Merge remote-tracking branch 'tinyusb/master' into n6_build

Signed-off-by: Zixun LI <[email protected]>

43 files changed, 4016 insertions, 2085 deletions

diff --git a/src/class/audio/audio.h b/src/class/audio/audio.h
index 0d1acadcc..cff38cc22 100644
--- a/src/class/audio/audio.h
+++ b/src/class/audio/audio.h
@@ -30,8 +30,8 @@
  *            Currently only MIDI subclass is supported
  *  @{ */
 
-#ifndef _TUSB_AUDIO_H__
-#define _TUSB_AUDIO_H__
+#ifndef TUSB_AUDIO_H__
+#define TUSB_AUDIO_H__
 
 #include "common/tusb_common.h"
 
@@ -39,917 +39,1255 @@
 extern "C" {
 #endif
 
-/// Audio Device Class Codes
+//--------------------------------------------------------------------+
+// GENERIC AUDIO CLASS CODES (COMMON TO UAC1 AND UAC2)
+//--------------------------------------------------------------------+
 
 /// A.2 - Audio Function Subclass Codes
-typedef enum
-{
+typedef enum {
   AUDIO_FUNCTION_SUBCLASS_UNDEFINED = 0x00,
 } audio_function_subclass_type_t;
 
 /// A.3 - Audio Function Protocol Codes
-typedef enum
-{
-  AUDIO_FUNC_PROTOCOL_CODE_UNDEF       = 0x00,
-  AUDIO_FUNC_PROTOCOL_CODE_V2          = 0x20, ///< Version 2.0
+typedef enum {
+  AUDIO_FUNC_PROTOCOL_CODE_UNDEF = 0x00,
+  AUDIO_FUNC_PROTOCOL_CODE_V1 = 0x00,///< Version 1.0 - same as undefined for backward compatibility
+  AUDIO_FUNC_PROTOCOL_CODE_V2 = 0x20,///< Version 2.0
 } audio_function_protocol_code_t;
 
 /// A.5 - Audio Interface Subclass Codes
-typedef enum
-{
+typedef enum {
   AUDIO_SUBCLASS_UNDEFINED = 0x00,
-  AUDIO_SUBCLASS_CONTROL         , ///< Audio Control
-  AUDIO_SUBCLASS_STREAMING       , ///< Audio Streaming
-  AUDIO_SUBCLASS_MIDI_STREAMING  , ///< MIDI Streaming
+  AUDIO_SUBCLASS_CONTROL,       ///< Audio Control
+  AUDIO_SUBCLASS_STREAMING,     ///< Audio Streaming
+  AUDIO_SUBCLASS_MIDI_STREAMING,///< MIDI Streaming
 } audio_subclass_type_t;
 
 /// A.6 - Audio Interface Protocol Codes
-typedef enum
-{
-  AUDIO_INT_PROTOCOL_CODE_UNDEF       = 0x00,
-  AUDIO_INT_PROTOCOL_CODE_V2          = 0x20, ///< Version 2.0
+typedef enum {
+  AUDIO_INT_PROTOCOL_CODE_UNDEF = 0x00,
+  AUDIO_INT_PROTOCOL_CODE_V1 = 0x00,///< Version 1.0 - same as undefined for backward compatibility
+  AUDIO_INT_PROTOCOL_CODE_V2 = 0x20,///< Version 2.0
 } audio_interface_protocol_code_t;
 
+/// Terminal Types
+
+/// 2.1 - Audio Class-Terminal Types
+typedef enum {
+  AUDIO_TERM_TYPE_USB_UNDEFINED = 0x0100,
+  AUDIO_TERM_TYPE_USB_STREAMING = 0x0101,
+  AUDIO_TERM_TYPE_USB_VENDOR_SPEC = 0x01FF,
+} audio_terminal_type_t;
+
+/// 2.2 - Audio Class-Input Terminal Types
+typedef enum {
+  AUDIO_TERM_TYPE_IN_UNDEFINED = 0x0200,
+  AUDIO_TERM_TYPE_IN_GENERIC_MIC = 0x0201,
+  AUDIO_TERM_TYPE_IN_DESKTOP_MIC = 0x0202,
+  AUDIO_TERM_TYPE_IN_PERSONAL_MIC = 0x0203,
+  AUDIO_TERM_TYPE_IN_OMNI_MIC = 0x0204,
+  AUDIO_TERM_TYPE_IN_ARRAY_MIC = 0x0205,
+  AUDIO_TERM_TYPE_IN_PROC_ARRAY_MIC = 0x0206,
+} audio_terminal_input_type_t;
+
+/// 2.3 - Audio Class-Output Terminal Types
+typedef enum {
+  AUDIO_TERM_TYPE_OUT_UNDEFINED = 0x0300,
+  AUDIO_TERM_TYPE_OUT_GENERIC_SPEAKER = 0x0301,
+  AUDIO_TERM_TYPE_OUT_HEADPHONES = 0x0302,
+  AUDIO_TERM_TYPE_OUT_HEAD_MNT_DISP_AUIDO = 0x0303,
+  AUDIO_TERM_TYPE_OUT_DESKTOP_SPEAKER = 0x0304,
+  AUDIO_TERM_TYPE_OUT_ROOM_SPEAKER = 0x0305,
+  AUDIO_TERM_TYPE_OUT_COMMUNICATION_SPEAKER = 0x0306,
+  AUDIO_TERM_TYPE_OUT_LOW_FRQ_EFFECTS_SPEAKER = 0x0307,
+} audio_terminal_output_type_t;
+
+/// Rest is yet to be implemented
+
+//--------------------------------------------------------------------+
+// USB AUDIO CLASS 1.0 (UAC1) DEFINITIONS
+//--------------------------------------------------------------------+
+
+/// A.5 - Audio Class-Specific AC Interface Descriptor Subtypes UAC1
+typedef enum {
+  AUDIO10_CS_AC_INTERFACE_AC_DESCRIPTOR_UNDEF = 0x00,
+  AUDIO10_CS_AC_INTERFACE_HEADER = 0x01,
+  AUDIO10_CS_AC_INTERFACE_INPUT_TERMINAL = 0x02,
+  AUDIO10_CS_AC_INTERFACE_OUTPUT_TERMINAL = 0x03,
+  AUDIO10_CS_AC_INTERFACE_MIXER_UNIT = 0x04,
+  AUDIO10_CS_AC_INTERFACE_SELECTOR_UNIT = 0x05,
+  AUDIO10_CS_AC_INTERFACE_FEATURE_UNIT = 0x06,
+  AUDIO10_CS_AC_INTERFACE_PROCESSING_UNIT = 0x07,
+  AUDIO10_CS_AC_INTERFACE_EXTENSION_UNIT = 0x08,
+} audio10_cs_ac_interface_subtype_t;
+
+/// A.6 - Audio Class-Specific AS Interface Descriptor Subtypes UAC1
+typedef enum {
+  AUDIO10_CS_AS_INTERFACE_AS_DESCRIPTOR_UNDEF = 0x00,
+  AUDIO10_CS_AS_INTERFACE_AS_GENERAL = 0x01,
+  AUDIO10_CS_AS_INTERFACE_FORMAT_TYPE = 0x02,
+} audio10_cs_as_interface_subtype_t;
+
+/// A.8 - Audio Class-Specific EP Descriptor Subtypes UAC1
+typedef enum {
+  AUDIO10_CS_EP_SUBTYPE_UNDEF = 0x00,
+  AUDIO10_CS_EP_SUBTYPE_GENERAL = 0x01,
+} audio10_cs_ep_subtype_t;
+
+/// A.9 - Audio Class-Specific Request Codes UAC1
+typedef enum {
+  AUDIO10_CS_REQ_UNDEF = 0x00,
+  AUDIO10_CS_REQ_SET_CUR = 0x01,
+  AUDIO10_CS_REQ_GET_CUR = 0x81,
+  AUDIO10_CS_REQ_SET_MIN = 0x02,
+  AUDIO10_CS_REQ_GET_MIN = 0x82,
+  AUDIO10_CS_REQ_SET_MAX = 0x03,
+  AUDIO10_CS_REQ_GET_MAX = 0x83,
+  AUDIO10_CS_REQ_SET_RES = 0x04,
+  AUDIO10_CS_REQ_GET_RES = 0x84,
+  AUDIO10_CS_REQ_SET_MEM = 0x05,
+  AUDIO10_CS_REQ_GET_MEM = 0x85,
+  AUDIO10_CS_REQ_GET_STAT = 0xFF,
+} audio10_cs_req_t;
+
+/// A.10.1 - Terminal Control Selectors UAC1
+typedef enum {
+  AUDIO10_TE_CTRL_UNDEF = 0x00,
+  AUDIO10_TE_CTRL_COPY_PROTECT = 0x01,
+} audio10_terminal_control_selector_t;
+
+/// A.10.2 - Feature Unit Control Selectors UAC1
+typedef enum {
+  AUDIO10_FU_CTRL_UNDEF = 0x00,
+  AUDIO10_FU_CTRL_MUTE = 0x01,
+  AUDIO10_FU_CTRL_VOLUME = 0x02,
+  AUDIO10_FU_CTRL_BASS = 0x03,
+  AUDIO10_FU_CTRL_MID = 0x04,
+  AUDIO10_FU_CTRL_TREBLE = 0x05,
+  AUDIO10_FU_CTRL_GRAPHIC_EQUALIZER = 0x06,
+  AUDIO10_FU_CTRL_AGC = 0x07,
+  AUDIO10_FU_CTRL_DELAY = 0x08,
+  AUDIO10_FU_CTRL_BASS_BOOST = 0x09,
+  AUDIO10_FU_CTRL_LOUDNESS = 0x0A,
+} audio10_feature_unit_control_selector_t;
+
+/// A.10.3.1 - Up/Down-mix Processing Unit Control Selectors UAC1
+typedef enum {
+  AUDIO10_UD_CTRL_UNDEF = 0x00,
+  AUDIO10_UD_CTRL_ENABLE = 0x01,
+  AUDIO10_UD_CTRL_MODE_SELECT = 0x02,
+} audio10_up_down_mix_control_selector_t;
+
+/// A.10.3.2 - Dolby Prologic Processing Unit Control Selectors UAC1
+typedef enum {
+  AUDIO10_DP_CTRL_UNDEF = 0x00,
+  AUDIO10_DP_CTRL_ENABLE = 0x01,
+  AUDIO10_DP_CTRL_MODE_SELECT = 0x02,
+} audio10_dolby_prologic_control_selector_t;
+
+/// A.10.3.3 - 3D Stereo Extender Processing Unit Control Selectors UAC1
+typedef enum {
+  AUDIO10_3D_CTRL_UNDEF = 0x00,
+  AUDIO10_3D_CTRL_ENABLE = 0x01,
+  AUDIO10_3D_CTRL_SPACIOUSNESS = 0x02,
+} audio10_3d_stereo_extender_control_selector_t;
+
+/// A.10.3.4 - Reverberation Processing Unit Control Selectors UAC1
+typedef enum {
+  AUDIO10_RV_CTRL_UNDEF = 0x00,
+  AUDIO10_RV_CTRL_ENABLE = 0x01,
+  AUDIO10_RV_CTRL_REVERB_LEVEL = 0x02,
+  AUDIO10_RV_CTRL_REVERB_TIME = 0x03,
+  AUDIO10_RV_CTRL_REVERB_FEEDBACK = 0x04,
+} audio10_reverberation_control_selector_t;
+
+/// A.10.3.5 - Chorus Processing Unit Control Selectors UAC1
+typedef enum {
+  AUDIO10_CH_CTRL_UNDEF = 0x00,
+  AUDIO10_CH_CTRL_ENABLE = 0x01,
+  AUDIO10_CH_CTRL_CHORUS_LEVEL = 0x02,
+  AUDIO10_CH_CTRL_CHORUS_RATE = 0x03,
+  AUDIO10_CH_CTRL_CHORUS_DEPTH = 0x04,
+} audio10_chorus_control_selector_t;
+
+/// A.10.3.6 - Dynamic Range Compressor Processing Unit Control Selectors UAC1
+typedef enum {
+  AUDIO10_DR_CTRL_UNDEF = 0x00,
+  AUDIO10_DR_CTRL_ENABLE = 0x01,
+  AUDIO10_DR_CTRL_COMPRESSION_RATE = 0x02,
+  AUDIO10_DR_CTRL_MAXAMPL = 0x03,
+  AUDIO10_DR_CTRL_THRESHOLD = 0x04,
+  AUDIO10_DR_CTRL_ATTACK_TIME = 0x05,
+  AUDIO10_DR_CTRL_RELEASE_TIME = 0x06,
+} audio10_dynamic_range_compression_control_selector_t;
+
+/// A.10.4 - Extension Unit Control Selectors UAC1
+typedef enum {
+  AUDIO10_XU_CTRL_UNDEF = 0x00,
+  AUDIO10_XU_CTRL_ENABLE = 0x01,
+} audio10_extension_unit_control_selector_t;
+
+/// A.10.5 - Endpoint Control Selectors UAC1
+typedef enum {
+  AUDIO10_EP_CTRL_UNDEF = 0x00,
+  AUDIO10_EP_CTRL_SAMPLING_FREQ = 0x01,
+  AUDIO10_EP_CTRL_PITCH = 0x02,
+} audio10_ep_control_selector_t;
+
+/// Audio Class-Specific AS Isochronous Data EP Attributes UAC1
+typedef enum {
+  AUDIO10_CS_AS_ISO_DATA_EP_ATT_MAX_PACKETS_ONLY = 0x80,
+  AUDIO10_CS_AS_ISO_DATA_EP_ATT_NON_MAX_PACKETS_OK = 0x00,
+  AUDIO10_CS_AS_ISO_DATA_EP_ATT_SAMPLING_FRQ = 0x01,
+  AUDIO10_CS_AS_ISO_DATA_EP_ATT_PITCH = 0x02,
+} audio10_cs_as_iso_data_ep_attribute_t;
+
+/// Audio Class-Specific AS Isochronous Data EP Lock Delay Units UAC1
+typedef enum {
+  AUDIO10_CS_AS_ISO_DATA_EP_LOCK_DELAY_UNIT_UNDEFINED = 0x00,
+  AUDIO10_CS_AS_ISO_DATA_EP_LOCK_DELAY_UNIT_MILLISEC = 0x01,
+  AUDIO10_CS_AS_ISO_DATA_EP_LOCK_DELAY_UNIT_PCM_SAMPLES = 0x02,
+} audio10_cs_as_iso_data_ep_lock_delay_unit_t;
+
+/// Audio Class-Feature Unit Controls UAC1
+typedef enum {
+  AUDIO10_FU_CONTROL_BM_MUTE = 1 << 0,
+  AUDIO10_FU_CONTROL_BM_VOLUME = 1 << 1,
+  AUDIO10_FU_CONTROL_BM_BASS = 1 << 2,
+  AUDIO10_FU_CONTROL_BM_MID = 1 << 3,
+  AUDIO10_FU_CONTROL_BM_TREBLE = 1 << 4,
+  AUDIO10_FU_CONTROL_BM_GRAPHIC_EQUALIZER = 1 << 5,
+  AUDIO10_FU_CONTROL_BM_AGC = 1 << 6,
+  AUDIO10_FU_CONTROL_BM_DELAY = 1 << 7,
+  AUDIO10_FU_CONTROL_BM_BASS_BOOST = 1 << 8,
+  AUDIO10_FU_CONTROL_BM_LOUDNESS = 1 << 9,
+} audio10_feature_unit_control_bitmap_t;
+
+/// A.1 - Audio Class-Format Type Codes UAC1
+typedef enum {
+  AUDIO10_FORMAT_TYPE_UNDEFINED = 0x00,
+  AUDIO10_FORMAT_TYPE_I = 0x01,
+  AUDIO10_FORMAT_TYPE_II = 0x02,
+  AUDIO10_FORMAT_TYPE_III = 0x03,
+} audio10_format_type_t;
+
+// A.1.1 - Audio Class-Audio Data Format Type I UAC1
+typedef enum {
+  AUDIO10_DATA_FORMAT_TYPE_I_PCM = 0x0001,
+  AUDIO10_DATA_FORMAT_TYPE_I_PCM8 = 0x0002,
+  AUDIO10_DATA_FORMAT_TYPE_I_IEEE_FLOAT = 0x0003,
+  AUDIO10_DATA_FORMAT_TYPE_I_ALAW = 0x0004,
+  AUDIO10_DATA_FORMAT_TYPE_I_MULAW = 0x0005,
+} audio10_data_format_type_I_t;
+
+// A.1.2 - Audio Class-Audio Data Format Type II UAC1
+typedef enum {
+  AUDIO10_DATA_FORMAT_TYPE_II_MPEG = 0x1001,
+  AUDIO10_DATA_FORMAT_TYPE_II_AC3 = 0x1002,
+} audio10_data_format_type_II_t;
+
+// A.1.3 - Audio Class-Audio Data Format Type III UAC1
+typedef enum {
+  AUDIO10_DATA_FORMAT_TYPE_III_IEC1937_AC3_1 = 0x2001,
+  AUDIO10_DATA_FORMAT_TYPE_III_IEC1937_MPEG1_L1_1 = 0x2002,
+  AUDIO10_DATA_FORMAT_TYPE_III_IEC1937_MPEG1_L23_1 = 0x2003,
+  AUDIO10_DATA_FORMAT_TYPE_III_IEC1937_MPEG2_EXT_1 = 0x2004,
+  AUDIO10_DATA_FORMAT_TYPE_III_IEC1937_MPEG2_L1_LS_1 = 0x2005,
+  AUDIO10_DATA_FORMAT_TYPE_III_IEC1937_MPEG2_L23_LS_1 = 0x2006,
+} audio10_data_format_type_III_t;
+
+/// Audio Class-Audio Channel Configuration UAC1 (Table A-7)
+typedef enum {
+  AUDIO10_CHANNEL_CONFIG_NON_PREDEFINED = 0x0000,
+  AUDIO10_CHANNEL_CONFIG_LEFT_FRONT = 0x0001,
+  AUDIO10_CHANNEL_CONFIG_RIGHT_FRONT = 0x0002,
+  AUDIO10_CHANNEL_CONFIG_CENTER_FRONT = 0x0004,
+  AUDIO10_CHANNEL_CONFIG_LOW_FRQ_EFFECTS = 0x0008,
+  AUDIO10_CHANNEL_CONFIG_LEFT_SURROUND = 0x0010,
+  AUDIO10_CHANNEL_CONFIG_RIGHT_SURROUND = 0x0020,
+  AUDIO10_CHANNEL_CONFIG_LEFT_OF_CENTER = 0x0040,
+  AUDIO10_CHANNEL_CONFIG_RIGHT_OF_CENTER = 0x0080,
+  AUDIO10_CHANNEL_CONFIG_SURROUND = 0x0100,
+  AUDIO10_CHANNEL_CONFIG_SIDE_LEFT = 0x0200,
+  AUDIO10_CHANNEL_CONFIG_SIDE_RIGHT = 0x0400,
+  AUDIO10_CHANNEL_CONFIG_TOP = 0x0800,
+} audio10_channel_config_t;
+
+
+//--------------------------------------------------------------------+
+// USB AUDIO CLASS 1.0 (UAC1) DESCRIPTORS
+//--------------------------------------------------------------------+
+
+/// AUDIO Class-Specific AC Interface Header Descriptor UAC1 (4.3.2)
+#define audio10_desc_cs_ac_interface_n_t(numInterfaces)                                                                                          \
+  struct TU_ATTR_PACKED {                                                                                                                        \
+    uint8_t bLength;                      /* Size of this descriptor in bytes: 8+n. */                                                           \
+    uint8_t bDescriptorType;              /* Descriptor Type. Value: TUSB_DESC_CS_INTERFACE. */                                                  \
+    uint8_t bDescriptorSubType;           /* Descriptor SubType. Value: AUDIO10_CS_AC_INTERFACE_HEADER. */                                       \
+    uint16_t bcdADC;                      /* Audio Device Class Specification Release Number in Binary-Coded Decimal. Value: 0x0100 for UAC1. */ \
+    uint16_t wTotalLength;                /* Total number of bytes returned for the class-specific AudioControl interface descriptor. */         \
+    uint8_t bInCollection;                /* The number of AudioStreaming and MIDIStreaming interfaces in the Audio Interface Collection. */     \
+    uint8_t baInterfaceNr[numInterfaces]; /* Interface number of the AudioStreaming or MIDIStreaming interface in the Collection. */             \
+  }
+
+/// AUDIO Input Terminal Descriptor UAC1 (4.3.2.1)
+typedef struct TU_ATTR_PACKED {
+  uint8_t bLength;           ///< Size of this descriptor in bytes: 12.
+  uint8_t bDescriptorType;   ///< Descriptor Type. Value: TUSB_DESC_CS_INTERFACE.
+  uint8_t bDescriptorSubType;///< Descriptor SubType. Value: AUDIO10_CS_AC_INTERFACE_INPUT_TERMINAL.
+  uint8_t bTerminalID;       ///< Constant uniquely identifying the Terminal within the audio function.
+  uint16_t wTerminalType;    ///< Constant characterizing the type of Terminal.
+  uint8_t bAssocTerminal;    ///< ID of the Output Terminal to which this Input Terminal is associated.
+  uint8_t bNrChannels;       ///< Number of logical output channels in the Terminal's output audio channel cluster.
+  uint16_t wChannelConfig;   ///< Describes the spatial location of the logical channels.
+  uint8_t iChannelNames;     ///< Index of a string descriptor, describing the name of the first logical channel.
+  uint8_t iTerminal;         ///< Index of a string descriptor, describing the Input Terminal.
+} audio10_desc_input_terminal_t;
+
+/// AUDIO Output Terminal Descriptor UAC1 (4.3.2.2)
+typedef struct TU_ATTR_PACKED {
+  uint8_t bLength;           ///< Size of this descriptor in bytes: 9.
+  uint8_t bDescriptorType;   ///< Descriptor Type. Value: TUSB_DESC_CS_INTERFACE.
+  uint8_t bDescriptorSubType;///< Descriptor SubType. Value: AUDIO10_CS_AC_INTERFACE_OUTPUT_TERMINAL.
+  uint8_t bTerminalID;       ///< Constant uniquely identifying the Terminal within the audio function.
+  uint16_t wTerminalType;    ///< Constant characterizing the type of Terminal.
+  uint8_t bAssocTerminal;    ///< Constant, identifying the Input Terminal to which this Output Terminal is associated.
+  uint8_t bSourceID;         ///< ID of the Unit or Terminal to which this Terminal is connected.
+  uint8_t iTerminal;         ///< Index of a string descriptor, describing the Output Terminal.
+} audio10_desc_output_terminal_t;
+
+/// AUDIO Mixer Unit Descriptor UAC1 (4.3.2.3)
+#define audio10_desc_mixer_unit_n_t(numInputPins, numControlBytes)                                                                 \
+  struct TU_ATTR_PACKED {                                                                                                          \
+    uint8_t bLength;                     /* Size of this descriptor in bytes: 10+p+n. */                                           \
+    uint8_t bDescriptorType;             /* Descriptor Type. Value: TUSB_DESC_CS_INTERFACE. */                                     \
+    uint8_t bDescriptorSubType;          /* Descriptor SubType. Value: AUDIO10_CS_AC_INTERFACE_MIXER_UNIT. */                      \
+    uint8_t bUnitID;                     /* Constant uniquely identifying the Unit within the audio function. */                   \
+    uint8_t bNrInPins;                   /* Number of Input Pins of this Unit: p. */                                               \
+    uint8_t baSourceID[numInputPins];    /* ID of the Unit or Terminal to which Input Pins of this Mixer Unit are connected. */    \
+    uint8_t bNrChannels;                 /* Number of logical output channels in the Mixer Unit's output audio channel cluster. */ \
+    uint16_t wChannelConfig;             /* Describes the spatial location of the logical channels. */                             \
+    uint8_t iChannelNames;               /* Index of a string descriptor, describing the name of the first logical channel. */     \
+    uint8_t bmControls[numControlBytes]; /* Mixer Unit Controls bitmap. */                                                         \
+    uint8_t iMixer;                      /* Index of a string descriptor, describing the Mixer Unit. */                            \
+  }
+
+/// AUDIO Selector Unit Descriptor UAC1 (4.3.2.4)
+#define audio10_desc_selector_unit_n_t(numInputPins)                                                                            \
+  struct TU_ATTR_PACKED {                                                                                                       \
+    uint8_t bLength;                  /* Size of this descriptor in bytes: 6+p. */                                              \
+    uint8_t bDescriptorType;          /* Descriptor Type. Value: TUSB_DESC_CS_INTERFACE. */                                     \
+    uint8_t bDescriptorSubType;       /* Descriptor SubType. Value: AUDIO10_CS_AC_INTERFACE_SELECTOR_UNIT. */                   \
+    uint8_t bUnitID;                  /* Constant uniquely identifying the Unit within the audio function. */                   \
+    uint8_t bNrInPins;                /* Number of Input Pins of this Unit: p. */                                               \
+    uint8_t baSourceID[numInputPins]; /* ID of the Unit or Terminal to which Input Pins of this Selector Unit are connected. */ \
+    uint8_t iSelector;                /* Index of a string descriptor, describing the Selector Unit. */                         \
+  }
+
+/// AUDIO Feature Unit Descriptor UAC1 (4.3.2.5)
+#define audio10_desc_feature_unit_n_t(numChannels, controlSize)                                                                     \
+  struct TU_ATTR_PACKED {                                                                                                           \
+    uint8_t bLength;                                      /* Size of this descriptor in bytes: 7+(ch+1)*n. */                       \
+    uint8_t bDescriptorType;                              /* Descriptor Type. Value: TUSB_DESC_CS_INTERFACE. */                     \
+    uint8_t bDescriptorSubType;                           /* Descriptor SubType. Value: AUDIO10_CS_AC_INTERFACE_FEATURE_UNIT. */    \
+    uint8_t bUnitID;                                      /* Constant uniquely identifying the Unit within the audio function. */   \
+    uint8_t bSourceID;                                    /* ID of the Unit or Terminal to which this Feature Unit is connected. */ \
+    uint8_t bControlSize;                                 /* Size in bytes of an element of the bmaControls() array. */             \
+    uint8_t bmaControls[(numChannels + 1) * controlSize]; /* Control bitmaps for master + logical channels. */                      \
+    uint8_t iFeature;                                     /* Index of a string descriptor, describing this Feature Unit. */         \
+  }
+
+/// AUDIO Processing Unit Descriptor UAC1 (4.3.2.6)
+#define audio10_desc_processing_unit_n_t(numInputPins, numControlBytes)                                                                 \
+  struct TU_ATTR_PACKED {                                                                                                               \
+    uint8_t bLength;                     /* Size of this descriptor in bytes: 13+p+n. */                                                \
+    uint8_t bDescriptorType;             /* Descriptor Type. Value: TUSB_DESC_CS_INTERFACE. */                                          \
+    uint8_t bDescriptorSubType;          /* Descriptor SubType. Value: AUDIO10_CS_AC_INTERFACE_PROCESSING_UNIT. */                      \
+    uint8_t bUnitID;                     /* Constant uniquely identifying the Unit within the audio function. */                        \
+    uint16_t wProcessType;               /* Constant identifying the type of processing this Unit is performing. */                     \
+    uint8_t bNrInPins;                   /* Number of Input Pins of this Unit: p. */                                                    \
+    uint8_t baSourceID[numInputPins];    /* ID of the Unit or Terminal to which Input Pins of this Processing Unit are connected. */    \
+    uint8_t bNrChannels;                 /* Number of logical output channels in the Processing Unit's output audio channel cluster. */ \
+    uint16_t wChannelConfig;             /* Describes the spatial location of the logical channels. */                                  \
+    uint8_t iChannelNames;               /* Index of a string descriptor, describing the name of the first logical channel. */          \
+    uint8_t bControlSize;                /* Size in bytes of the bmControls field. */                                                   \
+    uint8_t bmControls[numControlBytes]; /* Processing Unit Controls bitmap. */                                                         \
+    uint8_t iProcessing;                 /* Index of a string descriptor, describing the Processing Unit. */                            \
+  }
+
+/// AUDIO Extension Unit Descriptor UAC1 (4.3.2.7)
+#define audio10_desc_extension_unit_n_t(numInputPins, numControlBytes)                                                                 \
+  struct TU_ATTR_PACKED {                                                                                                              \
+    uint8_t bLength;                     /* Size of this descriptor in bytes: 13+p+n. */                                               \
+    uint8_t bDescriptorType;             /* Descriptor Type. Value: TUSB_DESC_CS_INTERFACE. */                                         \
+    uint8_t bDescriptorSubType;          /* Descriptor SubType. Value: AUDIO10_CS_AC_INTERFACE_EXTENSION_UNIT. */                      \
+    uint8_t bUnitID;                     /* Constant uniquely identifying the Unit within the audio function. */                       \
+    uint16_t wExtensionCode;             /* Vendor-specific code identifying the Extension Unit. */                                    \
+    uint8_t bNrInPins;                   /* Number of Input Pins of this Unit: p. */                                                   \
+    uint8_t baSourceID[numInputPins];    /* ID of the Unit or Terminal to which Input Pins of this Extension Unit are connected. */    \
+    uint8_t bNrChannels;                 /* Number of logical output channels in the Extension Unit's output audio channel cluster. */ \
+    uint16_t wChannelConfig;             /* Describes the spatial location of the logical channels. */                                 \
+    uint8_t iChannelNames;               /* Index of a string descriptor, describing the name of the first logical channel. */         \
+    uint8_t bControlSize;                /* Size in bytes of the bmControls field. */                                                  \
+    uint8_t bmControls[numControlBytes]; /* Extension Unit Controls bitmap. */                                                         \
+    uint8_t iExtension;                  /* Index of a string descriptor, describing the Extension Unit. */                            \
+  }
+
+/// AUDIO Class-Specific AS Interface Descriptor UAC1 (4.5.2)
+typedef struct TU_ATTR_PACKED {
+  uint8_t bLength;           ///< Size of this descriptor in bytes: 7.
+  uint8_t bDescriptorType;   ///< Descriptor Type. Value: TUSB_DESC_CS_INTERFACE.
+  uint8_t bDescriptorSubType;///< Descriptor SubType. Value: AUDIO10_CS_AS_INTERFACE_AS_GENERAL.
+  uint8_t bTerminalLink;     ///< The Terminal ID of the Terminal to which the endpoint of this interface is connected.
+  uint8_t bDelay;            ///< Expressed in number of frames.
+  uint16_t wFormatTag;       ///< The Audio Data Format that has to be used to communicate with this interface.
+} audio10_desc_cs_as_interface_t;
+
+/// AUDIO Type I Format Type Descriptor UAC1 (2.2.5)
+#define audio10_desc_type_I_format_n_t(numSamFreq)                                                                            \
+  struct TU_ATTR_PACKED {                                                                                                     \
+    uint8_t bLength;                  /* Size of this descriptor in bytes: 8+(ns*3). */                                       \
+    uint8_t bDescriptorType;          /* Descriptor Type. Value: TUSB_DESC_CS_INTERFACE. */                                   \
+    uint8_t bDescriptorSubType;       /* Descriptor SubType. Value: AUDIO10_CS_AS_INTERFACE_FORMAT_TYPE. */                   \
+    uint8_t bFormatType;              /* Constant identifying the Format Type the AudioStreaming interface is using. */       \
+    uint8_t bNrChannels;              /* Indicates the number of physical channels in the audio data stream. */               \
+    uint8_t bSubFrameSize;            /* The number of bytes occupied by one audio subframe. */                               \
+    uint8_t bBitResolution;           /* The number of effectively used bits from the available bits in an audio subframe. */ \
+    uint8_t bSamFreqType;             /* Indicates how the sampling frequency can be programmed. */                           \
+    uint8_t tSamFreq[numSamFreq * 3]; /* Sampling frequency or lower/upper bounds in Hz for the sampling frequency range. */  \
+  }
+
+/// AUDIO Type II Format Type Descriptor UAC1 (2.3.5)
+#define audio10_desc_type_II_format_n_t(numSamFreq)                                                                          \
+  struct TU_ATTR_PACKED {                                                                                                    \
+    uint8_t bLength;                  /* Size of this descriptor in bytes: 9+(ns*3). */                                      \
+    uint8_t bDescriptorType;          /* Descriptor Type. Value: TUSB_DESC_CS_INTERFACE. */                                  \
+    uint8_t bDescriptorSubType;       /* Descriptor SubType. Value: AUDIO10_CS_AS_INTERFACE_FORMAT_TYPE. */                  \
+    uint8_t bFormatType;              /* Constant identifying the Format Type the AudioStreaming interface is using. */      \
+    uint16_t wMaxBitRate;             /* Indicates the maximum number of bits per second this interface can handle. */       \
+    uint16_t wSamplesPerFrame;        /* Indicates the number of PCM audio samples contained in one encoded audio frame. */  \
+    uint8_t bSamFreqType;             /* Indicates how the sampling frequency can be programmed. */                          \
+    uint8_t tSamFreq[numSamFreq * 3]; /* Sampling frequency or lower/upper bounds in Hz for the sampling frequency range. */ \
+  }
+
+/// AUDIO Type III Format Type Descriptor UAC1 (2.4.5)
+#define audio10_desc_type_III_format_n_t(numSamFreq)                                                                          \
+  struct TU_ATTR_PACKED {                                                                                                     \
+    uint8_t bLength;                  /* Size of this descriptor in bytes: 8+(ns*3). */                                       \
+    uint8_t bDescriptorType;          /* Descriptor Type. Value: TUSB_DESC_CS_INTERFACE. */                                   \
+    uint8_t bDescriptorSubType;       /* Descriptor SubType. Value: AUDIO10_CS_AS_INTERFACE_FORMAT_TYPE. */                   \
+    uint8_t bFormatType;              /* Constant identifying the Format Type the AudioStreaming interface is using. */       \
+    uint8_t bNrChannels;              /* Indicates the number of physical channels in the audio data stream. */               \
+    uint8_t bSubFrameSize;            /* The number of bytes occupied by one audio subframe. */                               \
+    uint8_t bBitResolution;           /* The number of effectively used bits from the available bits in an audio subframe. */ \
+    uint8_t bSamFreqType;             /* Indicates how the sampling frequency can be programmed. */                           \
+    uint8_t tSamFreq[numSamFreq * 3]; /* Sampling frequency or lower/upper bounds in Hz for the sampling frequency range. */  \
+  }
+
+/// Standard AS Isochronous Audio Data Endpoint Descriptor UAC1 (4.6.1.1)
+typedef struct TU_ATTR_PACKED {
+  uint8_t bLength;         ///< Size of this descriptor in bytes: 9.
+  uint8_t bDescriptorType; ///< Descriptor Type. Value: TUSB_DESC_ENDPOINT.
+  uint8_t bEndpointAddress;///< The address of the endpoint on the USB device described by this descriptor.
+  struct TU_ATTR_PACKED {
+    uint8_t xfer  : 2;        // Control, ISO, Bulk, Interrupt
+    uint8_t sync  : 2;        // None, Asynchronous, Adaptive, Synchronous
+    uint8_t usage : 2;        // Data, Feedback, Implicit feedback
+    uint8_t       : 2;
+  } bmAttributes;
+  uint16_t wMaxPacketSize; ///< Maximum packet size this endpoint is capable of sending or receiving when this configuration is selected.
+  uint8_t bInterval;       ///< Interval for polling endpoint for data transfers.
+  uint8_t bRefresh;        ///< The rate at which the endpoint is refreshed.
+  uint8_t bSynchAddress;   ///< The address of the endpoint used to send synchronization information for the data endpoint.
+} audio10_desc_as_iso_data_ep_t;
+
+/// AUDIO Class-Specific AS Isochronous Audio Data Endpoint Descriptor UAC1 (4.6.1.2)
+typedef struct TU_ATTR_PACKED {
+  uint8_t bLength;           ///< Size of this descriptor in bytes: 7.
+  uint8_t bDescriptorType;   ///< Descriptor Type. Value: TUSB_DESC_CS_ENDPOINT.
+  uint8_t bDescriptorSubType;///< Descriptor SubType. Value: AUDIO10_CS_EP_SUBTYPE_GENERAL.
+  uint8_t bmAttributes;      ///< Bit 0: Sampling Frequency, Bit 1: Pitch, Bit 7: MaxPacketsOnly.
+  uint8_t bLockDelayUnits;   ///< Indicates the units used for the wLockDelay field.
+  uint16_t wLockDelay;       ///< Indicates the time it takes this endpoint to reliably lock its internal clock recovery circuitry.
+} audio10_desc_cs_as_iso_data_ep_t;
+
+/// AUDIO Interrupt Data Message Format UAC1 (3.7.1.2)
+typedef struct TU_ATTR_PACKED {
+  uint8_t bStatusType;///< Indicates the type of status information being reported.
+  uint8_t bOriginator;///< Indicates the entity that originated this status information.
+} audio10_interrupt_data_t;
+
+//--------------------------------------------------------------------+
+// USB AUDIO CLASS 2.0 (UAC2) DEFINITIONS
+//--------------------------------------------------------------------+
+
 /// A.7 - Audio Function Category Codes
-typedef enum
-{
-  AUDIO_FUNC_UNDEF              = 0x00,
-  AUDIO_FUNC_DESKTOP_SPEAKER    = 0x01,
-  AUDIO_FUNC_HOME_THEATER       = 0x02,
-  AUDIO_FUNC_MICROPHONE         = 0x03,
-  AUDIO_FUNC_HEADSET            = 0x04,
-  AUDIO_FUNC_TELEPHONE          = 0x05,
-  AUDIO_FUNC_CONVERTER          = 0x06,
-  AUDIO_FUNC_SOUND_RECODER      = 0x07,
-  AUDIO_FUNC_IO_BOX             = 0x08,
-  AUDIO_FUNC_MUSICAL_INSTRUMENT = 0x09,
-  AUDIO_FUNC_PRO_AUDIO          = 0x0A,
-  AUDIO_FUNC_AUDIO_VIDEO        = 0x0B,
-  AUDIO_FUNC_CONTROL_PANEL      = 0x0C,
-  AUDIO_FUNC_OTHER              = 0xFF,
-} audio_function_code_t;
+typedef enum {
+  AUDIO20_FUNC_UNDEF = 0x00,
+  AUDIO20_FUNC_DESKTOP_SPEAKER = 0x01,
+  AUDIO20_FUNC_HOME_THEATER = 0x02,
+  AUDIO20_FUNC_MICROPHONE = 0x03,
+  AUDIO20_FUNC_HEADSET = 0x04,
+  AUDIO20_FUNC_TELEPHONE = 0x05,
+  AUDIO20_FUNC_CONVERTER = 0x06,
+  AUDIO20_FUNC_SOUND_RECODER = 0x07,
+  AUDIO20_FUNC_IO_BOX = 0x08,
+  AUDIO20_FUNC_MUSICAL_INSTRUMENT = 0x09,
+  AUDIO20_FUNC_PRO_AUDIO = 0x0A,
+  AUDIO20_FUNC_AUDIO_VIDEO = 0x0B,
+  AUDIO20_FUNC_CONTROL_PANEL = 0x0C,
+  AUDIO20_FUNC_OTHER = 0xFF,
+} audio20_function_code_t;
 
 /// A.9 - Audio Class-Specific AC Interface Descriptor Subtypes UAC2
-typedef enum
-{
-  AUDIO_CS_AC_INTERFACE_AC_DESCRIPTOR_UNDEF   = 0x00,
-  AUDIO_CS_AC_INTERFACE_HEADER                = 0x01,
-  AUDIO_CS_AC_INTERFACE_INPUT_TERMINAL        = 0x02,
-  AUDIO_CS_AC_INTERFACE_OUTPUT_TERMINAL       = 0x03,
-  AUDIO_CS_AC_INTERFACE_MIXER_UNIT            = 0x04,
-  AUDIO_CS_AC_INTERFACE_SELECTOR_UNIT         = 0x05,
-  AUDIO_CS_AC_INTERFACE_FEATURE_UNIT          = 0x06,
-  AUDIO_CS_AC_INTERFACE_EFFECT_UNIT           = 0x07,
-  AUDIO_CS_AC_INTERFACE_PROCESSING_UNIT       = 0x08,
-  AUDIO_CS_AC_INTERFACE_EXTENSION_UNIT        = 0x09,
-  AUDIO_CS_AC_INTERFACE_CLOCK_SOURCE          = 0x0A,
-  AUDIO_CS_AC_INTERFACE_CLOCK_SELECTOR        = 0x0B,
-  AUDIO_CS_AC_INTERFACE_CLOCK_MULTIPLIER      = 0x0C,
-  AUDIO_CS_AC_INTERFACE_SAMPLE_RATE_CONVERTER = 0x0D,
-} audio_cs_ac_interface_subtype_t;
+typedef enum {
+  AUDIO20_CS_AC_INTERFACE_AC_DESCRIPTOR_UNDEF = 0x00,
+  AUDIO20_CS_AC_INTERFACE_HEADER = 0x01,
+  AUDIO20_CS_AC_INTERFACE_INPUT_TERMINAL = 0x02,
+  AUDIO20_CS_AC_INTERFACE_OUTPUT_TERMINAL = 0x03,
+  AUDIO20_CS_AC_INTERFACE_MIXER_UNIT = 0x04,
+  AUDIO20_CS_AC_INTERFACE_SELECTOR_UNIT = 0x05,
+  AUDIO20_CS_AC_INTERFACE_FEATURE_UNIT = 0x06,
+  AUDIO20_CS_AC_INTERFACE_EFFECT_UNIT = 0x07,
+  AUDIO20_CS_AC_INTERFACE_PROCESSING_UNIT = 0x08,
+  AUDIO20_CS_AC_INTERFACE_EXTENSION_UNIT = 0x09,
+  AUDIO20_CS_AC_INTERFACE_CLOCK_SOURCE = 0x0A,
+  AUDIO20_CS_AC_INTERFACE_CLOCK_SELECTOR = 0x0B,
+  AUDIO20_CS_AC_INTERFACE_CLOCK_MULTIPLIER = 0x0C,
+  AUDIO20_CS_AC_INTERFACE_SAMPLE_RATE_CONVERTER = 0x0D,
+} audio20_cs_ac_interface_subtype_t;
 
 /// A.10 - Audio Class-Specific AS Interface Descriptor Subtypes UAC2
-typedef enum
-{
-  AUDIO_CS_AS_INTERFACE_AS_DESCRIPTOR_UNDEF   = 0x00,
-  AUDIO_CS_AS_INTERFACE_AS_GENERAL            = 0x01,
-  AUDIO_CS_AS_INTERFACE_FORMAT_TYPE           = 0x02,
-  AUDIO_CS_AS_INTERFACE_ENCODER               = 0x03,
-  AUDIO_CS_AS_INTERFACE_DECODER               = 0x04,
-} audio_cs_as_interface_subtype_t;
+typedef enum {
+  AUDIO20_CS_AS_INTERFACE_AS_DESCRIPTOR_UNDEF = 0x00,
+  AUDIO20_CS_AS_INTERFACE_AS_GENERAL = 0x01,
+  AUDIO20_CS_AS_INTERFACE_FORMAT_TYPE = 0x02,
+  AUDIO20_CS_AS_INTERFACE_ENCODER = 0x03,
+  AUDIO20_CS_AS_INTERFACE_DECODER = 0x04,
+} audio20_cs_as_interface_subtype_t;
 
 /// A.11 - Effect Unit Effect Types
-typedef enum
-{
-  AUDIO_EFFECT_TYPE_UNDEF                     = 0x00,
-  AUDIO_EFFECT_TYPE_PARAM_EQ_SECTION          = 0x01,
-  AUDIO_EFFECT_TYPE_REVERBERATION             = 0x02,
-  AUDIO_EFFECT_TYPE_MOD_DELAY                 = 0x03,
-  AUDIO_EFFECT_TYPE_DYN_RANGE_COMP            = 0x04,
-} audio_effect_unit_effect_type_t;
+typedef enum {
+  AUDIO20_EFFECT_TYPE_UNDEF = 0x00,
+  AUDIO20_EFFECT_TYPE_PARAM_EQ_SECTION = 0x01,
+  AUDIO20_EFFECT_TYPE_REVERBERATION = 0x02,
+  AUDIO20_EFFECT_TYPE_MOD_DELAY = 0x03,
+  AUDIO20_EFFECT_TYPE_DYN_RANGE_COMP = 0x04,
+} audio20_effect_unit_effect_type_t;
 
 /// A.12 - Processing Unit Process Types
-typedef enum
-{
-  AUDIO_PROCESS_TYPE_UNDEF                    = 0x00,
-  AUDIO_PROCESS_TYPE_UP_DOWN_MIX              = 0x01,
-  AUDIO_PROCESS_TYPE_DOLBY_PROLOGIC           = 0x02,
-  AUDIO_PROCESS_TYPE_STEREO_EXTENDER          = 0x03,
-} audio_processing_unit_process_type_t;
+typedef enum {
+  AUDIO20_PROCESS_TYPE_UNDEF = 0x00,
+  AUDIO20_PROCESS_TYPE_UP_DOWN_MIX = 0x01,
+  AUDIO20_PROCESS_TYPE_DOLBY_PROLOGIC = 0x02,
+  AUDIO20_PROCESS_TYPE_STEREO_EXTENDER = 0x03,
+} audio20_processing_unit_process_type_t;
 
 /// A.13 - Audio Class-Specific EP Descriptor Subtypes UAC2
-typedef enum
-{
-  AUDIO_CS_EP_SUBTYPE_UNDEF                   = 0x00,
-  AUDIO_CS_EP_SUBTYPE_GENERAL                 = 0x01,
-} audio_cs_ep_subtype_t;
+typedef enum {
+  AUDIO20_CS_EP_SUBTYPE_UNDEF = 0x00,
+  AUDIO20_CS_EP_SUBTYPE_GENERAL = 0x01,
+} audio20_cs_ep_subtype_t;
 
-/// A.14 - Audio Class-Specific Request Codes
-typedef enum
-{
-  AUDIO_CS_REQ_UNDEF                          = 0x00,
-  AUDIO_CS_REQ_CUR                            = 0x01,
-  AUDIO_CS_REQ_RANGE                          = 0x02,
-  AUDIO_CS_REQ_MEM                            = 0x03,
-} audio_cs_req_t;
+/// A.14 - Audio Class-Specific Request Codes UAC2
+typedef enum {
+  AUDIO20_CS_REQ_UNDEF = 0x00,
+  AUDIO20_CS_REQ_CUR = 0x01,
+  AUDIO20_CS_REQ_RANGE = 0x02,
+  AUDIO20_CS_REQ_MEM = 0x03,
+} audio20_cs_req_t;
 
-/// A.17 - Control Selector Codes
+/// A.17 - Control Selector Codes UAC2
 
 /// A.17.1 - Clock Source Control Selectors
-typedef enum
-{
-  AUDIO_CS_CTRL_UNDEF                         = 0x00,
-  AUDIO_CS_CTRL_SAM_FREQ                      = 0x01,
-  AUDIO_CS_CTRL_CLK_VALID                     = 0x02,
-} audio_clock_src_control_selector_t;
+typedef enum {
+  AUDIO20_CS_CTRL_UNDEF = 0x00,
+  AUDIO20_CS_CTRL_SAM_FREQ = 0x01,
+  AUDIO20_CS_CTRL_CLK_VALID = 0x02,
+} audio20_clock_src_control_selector_t;
 
 /// A.17.2 - Clock Selector Control Selectors
-typedef enum
-{
-  AUDIO_CX_CTRL_UNDEF                         = 0x00,
-  AUDIO_CX_CTRL_CONTROL                       = 0x01,
-} audio_clock_sel_control_selector_t;
+typedef enum {
+  AUDIO20_CX_CTRL_UNDEF = 0x00,
+  AUDIO20_CX_CTRL_CONTROL = 0x01,
+} audio20_clock_sel_control_selector_t;
 
 /// A.17.3 - Clock Multiplier Control Selectors
-typedef enum
-{
-  AUDIO_CM_CTRL_UNDEF                         = 0x00,
-  AUDIO_CM_CTRL_NUMERATOR_CONTROL             = 0x01,
-  AUDIO_CM_CTRL_DENOMINATOR_CONTROL           = 0x02,
-} audio_clock_mul_control_selector_t;
+typedef enum {
+  AUDIO20_CM_CTRL_UNDEF = 0x00,
+  AUDIO20_CM_CTRL_NUMERATOR_CONTROL = 0x01,
+  AUDIO20_CM_CTRL_DENOMINATOR_CONTROL = 0x02,
+} audio20_clock_mul_control_selector_t;
 
-/// A.17.4 - Terminal Control Selectors
-typedef enum
-{
-  AUDIO_TE_CTRL_UNDEF                         = 0x00,
-  AUDIO_TE_CTRL_COPY_PROTECT                  = 0x01,
-  AUDIO_TE_CTRL_CONNECTOR                     = 0x02,
-  AUDIO_TE_CTRL_OVERLOAD                      = 0x03,
-  AUDIO_TE_CTRL_CLUSTER                       = 0x04,
-  AUDIO_TE_CTRL_UNDERFLOW                     = 0x05,
-  AUDIO_TE_CTRL_OVERFLOW                      = 0x06,
-  AUDIO_TE_CTRL_LATENCY                       = 0x07,
-} audio_terminal_control_selector_t;
+/// A.17.4 - Terminal Control Selectors UAC2
+typedef enum {
+  AUDIO20_TE_CTRL_UNDEF = 0x00,
+  AUDIO20_TE_CTRL_COPY_PROTECT = 0x01,
+  AUDIO20_TE_CTRL_CONNECTOR = 0x02,
+  AUDIO20_TE_CTRL_OVERLOAD = 0x03,
+  AUDIO20_TE_CTRL_CLUSTER = 0x04,
+  AUDIO20_TE_CTRL_UNDERFLOW = 0x05,
+  AUDIO20_TE_CTRL_OVERFLOW = 0x06,
+  AUDIO20_TE_CTRL_LATENCY = 0x07,
+} audio20_terminal_control_selector_t;
 
 /// A.17.5 - Mixer Control Selectors
-typedef enum
-{
-  AUDIO_MU_CTRL_UNDEF                         = 0x00,
-  AUDIO_MU_CTRL_MIXER                         = 0x01,
-  AUDIO_MU_CTRL_CLUSTER                       = 0x02,
-  AUDIO_MU_CTRL_UNDERFLOW                     = 0x03,
-  AUDIO_MU_CTRL_OVERFLOW                      = 0x04,
-  AUDIO_MU_CTRL_LATENCY                       = 0x05,
-} audio_mixer_control_selector_t;
+typedef enum {
+  AUDIO20_MU_CTRL_UNDEF = 0x00,
+  AUDIO20_MU_CTRL_MIXER = 0x01,
+  AUDIO20_MU_CTRL_CLUSTER = 0x02,
+  AUDIO20_MU_CTRL_UNDERFLOW = 0x03,
+  AUDIO20_MU_CTRL_OVERFLOW = 0x04,
+  AUDIO20_MU_CTRL_LATENCY = 0x05,
+} audio20_mixer_control_selector_t;
 
 /// A.17.6 - Selector Control Selectors
-typedef enum
-{
-  AUDIO_SU_CTRL_UNDEF                         = 0x00,
-  AUDIO_SU_CTRL_SELECTOR                      = 0x01,
-  AUDIO_SU_CTRL_LATENCY                       = 0x02,
-} audio_sel_control_selector_t;
+typedef enum {
+  AUDIO20_SU_CTRL_UNDEF = 0x00,
+  AUDIO20_SU_CTRL_SELECTOR = 0x01,
+  AUDIO20_SU_CTRL_LATENCY = 0x02,
+} audio20_sel_control_selector_t;
 
-/// A.17.7 - Feature Unit Control Selectors
-typedef enum
-{
-  AUDIO_FU_CTRL_UNDEF                         = 0x00,
-  AUDIO_FU_CTRL_MUTE                          = 0x01,
-  AUDIO_FU_CTRL_VOLUME                        = 0x02,
-  AUDIO_FU_CTRL_BASS                          = 0x03,
-  AUDIO_FU_CTRL_MID                           = 0x04,
-  AUDIO_FU_CTRL_TREBLE                        = 0x05,
-  AUDIO_FU_CTRL_GRAPHIC_EQUALIZER             = 0x06,
-  AUDIO_FU_CTRL_AGC                           = 0x07,
-  AUDIO_FU_CTRL_DELAY                         = 0x08,
-  AUDIO_FU_CTRL_BASS_BOOST                    = 0x09,
-  AUDIO_FU_CTRL_LOUDNESS                      = 0x0A,
-  AUDIO_FU_CTRL_INPUT_GAIN                    = 0x0B,
-  AUDIO_FU_CTRL_GAIN_PAD                      = 0x0C,
-  AUDIO_FU_CTRL_INVERTER                      = 0x0D,
-  AUDIO_FU_CTRL_UNDERFLOW                     = 0x0E,
-  AUDIO_FU_CTRL_OVERVLOW                      = 0x0F,
-  AUDIO_FU_CTRL_LATENCY                       = 0x10,
-} audio_feature_unit_control_selector_t;
+/// A.17.7 - Feature Unit Control Selectors UAC2
+typedef enum {
+  AUDIO20_FU_CTRL_UNDEF = 0x00,
+  AUDIO20_FU_CTRL_MUTE = 0x01,
+  AUDIO20_FU_CTRL_VOLUME = 0x02,
+  AUDIO20_FU_CTRL_BASS = 0x03,
+  AUDIO20_FU_CTRL_MID = 0x04,
+  AUDIO20_FU_CTRL_TREBLE = 0x05,
+  AUDIO20_FU_CTRL_GRAPHIC_EQUALIZER = 0x06,
+  AUDIO20_FU_CTRL_AGC = 0x07,
+  AUDIO20_FU_CTRL_DELAY = 0x08,
+  AUDIO20_FU_CTRL_BASS_BOOST = 0x09,
+  AUDIO20_FU_CTRL_LOUDNESS = 0x0A,
+  AUDIO20_FU_CTRL_INPUT_GAIN = 0x0B,
+  AUDIO20_FU_CTRL_GAIN_PAD = 0x0C,
+  AUDIO20_FU_CTRL_INVERTER = 0x0D,
+  AUDIO20_FU_CTRL_UNDERFLOW = 0x0E,
+  AUDIO20_FU_CTRL_OVERVLOW = 0x0F,
+  AUDIO20_FU_CTRL_LATENCY = 0x10,
+} audio20_feature_unit_control_selector_t;
 
 /// A.17.8 Effect Unit Control Selectors
 
 /// A.17.8.1 Parametric Equalizer Section Effect Unit Control Selectors
-typedef enum
-{
-  AUDIO_PE_CTRL_UNDEF                         = 0x00,
-  AUDIO_PE_CTRL_ENABLE                        = 0x01,
-  AUDIO_PE_CTRL_CENTERFREQ                    = 0x02,
-  AUDIO_PE_CTRL_QFACTOR                       = 0x03,
-  AUDIO_PE_CTRL_GAIN                          = 0x04,
-  AUDIO_PE_CTRL_UNDERFLOW                     = 0x05,
-  AUDIO_PE_CTRL_OVERFLOW                      = 0x06,
-  AUDIO_PE_CTRL_LATENCY                       = 0x07,
-} audio_parametric_equalizer_control_selector_t;
+typedef enum {
+  AUDIO20_PE_CTRL_UNDEF = 0x00,
+  AUDIO20_PE_CTRL_ENABLE = 0x01,
+  AUDIO20_PE_CTRL_CENTERFREQ = 0x02,
+  AUDIO20_PE_CTRL_QFACTOR = 0x03,
+  AUDIO20_PE_CTRL_GAIN = 0x04,
+  AUDIO20_PE_CTRL_UNDERFLOW = 0x05,
+  AUDIO20_PE_CTRL_OVERFLOW = 0x06,
+  AUDIO20_PE_CTRL_LATENCY = 0x07,
+} audio20_parametric_equalizer_control_selector_t;
 
 /// A.17.8.2 Reverberation Effect Unit Control Selectors
-typedef enum
-{
-  AUDIO_RV_CTRL_UNDEF                         = 0x00,
-  AUDIO_RV_CTRL_ENABLE                        = 0x01,
-  AUDIO_RV_CTRL_TYPE                          = 0x02,
-  AUDIO_RV_CTRL_LEVEL                         = 0x03,
-  AUDIO_RV_CTRL_TIME                          = 0x04,
-  AUDIO_RV_CTRL_FEEDBACK                      = 0x05,
-  AUDIO_RV_CTRL_PREDELAY                      = 0x06,
-  AUDIO_RV_CTRL_DENSITY                       = 0x07,
-  AUDIO_RV_CTRL_HIFREQ_ROLLOFF                = 0x08,
-  AUDIO_RV_CTRL_UNDERFLOW                     = 0x09,
-  AUDIO_RV_CTRL_OVERFLOW                      = 0x0A,
-  AUDIO_RV_CTRL_LATENCY                       = 0x0B,
-} audio_reverberation_effect_control_selector_t;
+typedef enum {
+  AUDIO20_RV_CTRL_UNDEF = 0x00,
+  AUDIO20_RV_CTRL_ENABLE = 0x01,
+  AUDIO20_RV_CTRL_TYPE = 0x02,
+  AUDIO20_RV_CTRL_LEVEL = 0x03,
+  AUDIO20_RV_CTRL_TIME = 0x04,
+  AUDIO20_RV_CTRL_FEEDBACK = 0x05,
+  AUDIO20_RV_CTRL_PREDELAY = 0x06,
+  AUDIO20_RV_CTRL_DENSITY = 0x07,
+  AUDIO20_RV_CTRL_HIFREQ_ROLLOFF = 0x08,
+  AUDIO20_RV_CTRL_UNDERFLOW = 0x09,
+  AUDIO20_RV_CTRL_OVERFLOW = 0x0A,
+  AUDIO20_RV_CTRL_LATENCY = 0x0B,
+} audio20_reverberation_effect_control_selector_t;
 
 /// A.17.8.3 Modulation Delay Effect Unit Control Selectors
-typedef enum
-{
-  AUDIO_MD_CTRL_UNDEF                         = 0x00,
-  AUDIO_MD_CTRL_ENABLE                        = 0x01,
-  AUDIO_MD_CTRL_BALANCE                       = 0x02,
-  AUDIO_MD_CTRL_RATE                          = 0x03,
-  AUDIO_MD_CTRL_DEPTH                         = 0x04,
-  AUDIO_MD_CTRL_TIME                          = 0x05,
-  AUDIO_MD_CTRL_FEEDBACK                      = 0x06,
-  AUDIO_MD_CTRL_UNDERFLOW                     = 0x07,
-  AUDIO_MD_CTRL_OVERFLOW                      = 0x08,
-  AUDIO_MD_CTRL_LATENCY                       = 0x09,
-} audio_modulation_delay_control_selector_t;
+typedef enum {
+  AUDIO20_MD_CTRL_UNDEF = 0x00,
+  AUDIO20_MD_CTRL_ENABLE = 0x01,
+  AUDIO20_MD_CTRL_BALANCE = 0x02,
+  AUDIO20_MD_CTRL_RATE = 0x03,
+  AUDIO20_MD_CTRL_DEPTH = 0x04,
+  AUDIO20_MD_CTRL_TIME = 0x05,
+  AUDIO20_MD_CTRL_FEEDBACK = 0x06,
+  AUDIO20_MD_CTRL_UNDERFLOW = 0x07,
+  AUDIO20_MD_CTRL_OVERFLOW = 0x08,
+  AUDIO20_MD_CTRL_LATENCY = 0x09,
+} audio20_modulation_delay_control_selector_t;
 
 /// A.17.8.4 Dynamic Range Compressor Effect Unit Control Selectors
-typedef enum
-{
-  AUDIO_DR_CTRL_UNDEF                         = 0x00,
-  AUDIO_DR_CTRL_ENABLE                        = 0x01,
-  AUDIO_DR_CTRL_COMPRESSION_RATE              = 0x02,
-  AUDIO_DR_CTRL_MAXAMPL                       = 0x03,
-  AUDIO_DR_CTRL_THRESHOLD                     = 0x04,
-  AUDIO_DR_CTRL_ATTACK_TIME                   = 0x05,
-  AUDIO_DR_CTRL_RELEASE_TIME                  = 0x06,
-  AUDIO_DR_CTRL_UNDERFLOW                     = 0x07,
-  AUDIO_DR_CTRL_OVERFLOW                      = 0x08,
-  AUDIO_DR_CTRL_LATENCY                       = 0x09,
-} audio_dynamic_range_compression_control_selector_t;
+typedef enum {
+  AUDIO20_DR_CTRL_UNDEF = 0x00,
+  AUDIO20_DR_CTRL_ENABLE = 0x01,
+  AUDIO20_DR_CTRL_COMPRESSION_RATE = 0x02,
+  AUDIO20_DR_CTRL_MAXAMPL = 0x03,
+  AUDIO20_DR_CTRL_THRESHOLD = 0x04,
+  AUDIO20_DR_CTRL_ATTACK_TIME = 0x05,
+  AUDIO20_DR_CTRL_RELEASE_TIME = 0x06,
+  AUDIO20_DR_CTRL_UNDERFLOW = 0x07,
+  AUDIO20_DR_CTRL_OVERFLOW = 0x08,
+  AUDIO20_DR_CTRL_LATENCY = 0x09,
+} audio20_dynamic_range_compression_control_selector_t;
 
 /// A.17.9 Processing Unit Control Selectors
 
 /// A.17.9.1 Up/Down-mix Processing Unit Control Selectors
-typedef enum
-{
-  AUDIO_UD_CTRL_UNDEF                         = 0x00,
-  AUDIO_UD_CTRL_ENABLE                        = 0x01,
-  AUDIO_UD_CTRL_MODE_SELECT                   = 0x02,
-  AUDIO_UD_CTRL_CLUSTER                       = 0x03,
-  AUDIO_UD_CTRL_UNDERFLOW                     = 0x04,
-  AUDIO_UD_CTRL_OVERFLOW                      = 0x05,
-  AUDIO_UD_CTRL_LATENCY                       = 0x06,
-} audio_up_down_mix_control_selector_t;
+typedef enum {
+  AUDIO20_UD_CTRL_UNDEF = 0x00,
+  AUDIO20_UD_CTRL_ENABLE = 0x01,
+  AUDIO20_UD_CTRL_MODE_SELECT = 0x02,
+  AUDIO20_UD_CTRL_CLUSTER = 0x03,
+  AUDIO20_UD_CTRL_UNDERFLOW = 0x04,
+  AUDIO20_UD_CTRL_OVERFLOW = 0x05,
+  AUDIO20_UD_CTRL_LATENCY = 0x06,
+} audio20_up_down_mix_control_selector_t;
 
 /// A.17.9.2 Dolby Prologic ™ Processing Unit Control Selectors
-typedef enum
-{
-  AUDIO_DP_CTRL_UNDEF                         = 0x00,
-  AUDIO_DP_CTRL_ENABLE                        = 0x01,
-  AUDIO_DP_CTRL_MODE_SELECT                   = 0x02,
-  AUDIO_DP_CTRL_CLUSTER                       = 0x03,
-  AUDIO_DP_CTRL_UNDERFLOW                     = 0x04,
-  AUDIO_DP_CTRL_OVERFLOW                      = 0x05,
-  AUDIO_DP_CTRL_LATENCY                       = 0x06,
-} audio_dolby_prologic_control_selector_t;
+typedef enum {
+  AUDIO20_DP_CTRL_UNDEF = 0x00,
+  AUDIO20_DP_CTRL_ENABLE = 0x01,
+  AUDIO20_DP_CTRL_MODE_SELECT = 0x02,
+  AUDIO20_DP_CTRL_CLUSTER = 0x03,
+  AUDIO20_DP_CTRL_UNDERFLOW = 0x04,
+  AUDIO20_DP_CTRL_OVERFLOW = 0x05,
+  AUDIO20_DP_CTRL_LATENCY = 0x06,
+} audio20_dolby_prologic_control_selector_t;
 
 /// A.17.9.3 Stereo Extender Processing Unit Control Selectors
-typedef enum
-{
-  AUDIO_ST_EXT_CTRL_UNDEF                     = 0x00,
-  AUDIO_ST_EXT_CTRL_ENABLE                    = 0x01,
-  AUDIO_ST_EXT_CTRL_WIDTH                     = 0x02,
-  AUDIO_ST_EXT_CTRL_UNDERFLOW                 = 0x03,
-  AUDIO_ST_EXT_CTRL_OVERFLOW                  = 0x04,
-  AUDIO_ST_EXT_CTRL_LATENCY                   = 0x05,
-} audio_stereo_extender_control_selector_t;
+typedef enum {
+  AUDIO20_ST_EXT_CTRL_UNDEF = 0x00,
+  AUDIO20_ST_EXT_CTRL_ENABLE = 0x01,
+  AUDIO20_ST_EXT_CTRL_WIDTH = 0x02,
+  AUDIO20_ST_EXT_CTRL_UNDERFLOW = 0x03,
+  AUDIO20_ST_EXT_CTRL_OVERFLOW = 0x04,
+  AUDIO20_ST_EXT_CTRL_LATENCY = 0x05,
+} audio20_stereo_extender_control_selector_t;
 
 /// A.17.10 Extension Unit Control Selectors
-typedef enum
-{
-  AUDIO_XU_CTRL_UNDEF                         = 0x00,
-  AUDIO_XU_CTRL_ENABLE                        = 0x01,
-  AUDIO_XU_CTRL_CLUSTER                       = 0x02,
-  AUDIO_XU_CTRL_UNDERFLOW                     = 0x03,
-  AUDIO_XU_CTRL_OVERFLOW                      = 0x04,
-  AUDIO_XU_CTRL_LATENCY                       = 0x05,
-} audio_extension_unit_control_selector_t;
+typedef enum {
+  AUDIO20_XU_CTRL_UNDEF = 0x00,
+  AUDIO20_XU_CTRL_ENABLE = 0x01,
+  AUDIO20_XU_CTRL_CLUSTER = 0x02,
+  AUDIO20_XU_CTRL_UNDERFLOW = 0x03,
+  AUDIO20_XU_CTRL_OVERFLOW = 0x04,
+  AUDIO20_XU_CTRL_LATENCY = 0x05,
+} audio20_extension_unit_control_selector_t;
 
 /// A.17.11 AudioStreaming Interface Control Selectors
-typedef enum
-{
-  AUDIO_AS_CTRL_UNDEF                         = 0x00,
-  AUDIO_AS_CTRL_ACT_ALT_SETTING               = 0x01,
-  AUDIO_AS_CTRL_VAL_ALT_SETTINGS              = 0x02,
-  AUDIO_AS_CTRL_AUDIO_DATA_FORMAT             = 0x03,
-} audio_audiostreaming_interface_control_selector_t;
+typedef enum {
+  AUDIO20_AS_CTRL_UNDEF = 0x00,
+  AUDIO20_AS_CTRL_ACT_ALT_SETTING = 0x01,
+  AUDIO20_AS_CTRL_VAL_ALT_SETTINGS = 0x02,
+  AUDIO20_AS_CTRL_AUDIO_DATA_FORMAT = 0x03,
+} audio20_audiostreaming_interface_control_selector_t;
 
 /// A.17.12 Encoder Control Selectors
-typedef enum
-{
-  AUDIO_EN_CTRL_UNDEF                         = 0x00,
-  AUDIO_EN_CTRL_BIT_RATE                      = 0x01,
-  AUDIO_EN_CTRL_QUALITY                       = 0x02,
-  AUDIO_EN_CTRL_VBR                           = 0x03,
-  AUDIO_EN_CTRL_TYPE                          = 0x04,
-  AUDIO_EN_CTRL_UNDERFLOW                     = 0x05,
-  AUDIO_EN_CTRL_OVERFLOW                      = 0x06,
-  AUDIO_EN_CTRL_ENCODER_ERROR                 = 0x07,
-  AUDIO_EN_CTRL_PARAM1                        = 0x08,
-  AUDIO_EN_CTRL_PARAM2                        = 0x09,
-  AUDIO_EN_CTRL_PARAM3                        = 0x0A,
-  AUDIO_EN_CTRL_PARAM4                        = 0x0B,
-  AUDIO_EN_CTRL_PARAM5                        = 0x0C,
-  AUDIO_EN_CTRL_PARAM6                        = 0x0D,
-  AUDIO_EN_CTRL_PARAM7                        = 0x0E,
-  AUDIO_EN_CTRL_PARAM8                        = 0x0F,
-} audio_encoder_control_selector_t;
+typedef enum {
+  AUDIO20_EN_CTRL_UNDEF = 0x00,
+  AUDIO20_EN_CTRL_BIT_RATE = 0x01,
+  AUDIO20_EN_CTRL_QUALITY = 0x02,
+  AUDIO20_EN_CTRL_VBR = 0x03,
+  AUDIO20_EN_CTRL_TYPE = 0x04,
+  AUDIO20_EN_CTRL_UNDERFLOW = 0x05,
+  AUDIO20_EN_CTRL_OVERFLOW = 0x06,
+  AUDIO20_EN_CTRL_ENCODER_ERROR = 0x07,
+  AUDIO20_EN_CTRL_PARAM1 = 0x08,
+  AUDIO20_EN_CTRL_PARAM2 = 0x09,
+  AUDIO20_EN_CTRL_PARAM3 = 0x0A,
+  AUDIO20_EN_CTRL_PARAM4 = 0x0B,
+  AUDIO20_EN_CTRL_PARAM5 = 0x0C,
+  AUDIO20_EN_CTRL_PARAM6 = 0x0D,
+  AUDIO20_EN_CTRL_PARAM7 = 0x0E,
+  AUDIO20_EN_CTRL_PARAM8 = 0x0F,
+} audio20_encoder_control_selector_t;
 
 /// A.17.13 Decoder Control Selectors
 
 /// A.17.13.1 MPEG Decoder Control Selectors
-typedef enum
-{
-  AUDIO_MPD_CTRL_UNDEF                        = 0x00,
-  AUDIO_MPD_CTRL_DUAL_CHANNEL                 = 0x01,
-  AUDIO_MPD_CTRL_SECOND_STEREO                = 0x02,
-  AUDIO_MPD_CTRL_MULTILINGUAL                 = 0x03,
-  AUDIO_MPD_CTRL_DYN_RANGE                    = 0x04,
-  AUDIO_MPD_CTRL_SCALING                      = 0x05,
-  AUDIO_MPD_CTRL_HILO_SCALING                 = 0x06,
-  AUDIO_MPD_CTRL_UNDERFLOW                    = 0x07,
-  AUDIO_MPD_CTRL_OVERFLOW                     = 0x08,
-  AUDIO_MPD_CTRL_DECODER_ERROR                = 0x09,
-} audio_MPEG_decoder_control_selector_t;
+typedef enum {
+  AUDIO20_MPD_CTRL_UNDEF = 0x00,
+  AUDIO20_MPD_CTRL_DUAL_CHANNEL = 0x01,
+  AUDIO20_MPD_CTRL_SECOND_STEREO = 0x02,
+  AUDIO20_MPD_CTRL_MULTILINGUAL = 0x03,
+  AUDIO20_MPD_CTRL_DYN_RANGE = 0x04,
+  AUDIO20_MPD_CTRL_SCALING = 0x05,
+  AUDIO20_MPD_CTRL_HILO_SCALING = 0x06,
+  AUDIO20_MPD_CTRL_UNDERFLOW = 0x07,
+  AUDIO20_MPD_CTRL_OVERFLOW = 0x08,
+  AUDIO20_MPD_CTRL_DECODER_ERROR = 0x09,
+} audio20_MPEG_decoder_control_selector_t;
 
 /// A.17.13.2 AC-3 Decoder Control Selectors
-typedef enum
-{
-  AUDIO_AD_CTRL_UNDEF                         = 0x00,
-  AUDIO_AD_CTRL_MODE                          = 0x01,
-  AUDIO_AD_CTRL_DYN_RANGE                     = 0x02,
-  AUDIO_AD_CTRL_SCALING                       = 0x03,
-  AUDIO_AD_CTRL_HILO_SCALING                  = 0x04,
-  AUDIO_AD_CTRL_UNDERFLOW                     = 0x05,
-  AUDIO_AD_CTRL_OVERFLOW                      = 0x06,
-  AUDIO_AD_CTRL_DECODER_ERROR                 = 0x07,
-} audio_AC3_decoder_control_selector_t;
+typedef enum {
+  AUDIO20_AD_CTRL_UNDEF = 0x00,
+  AUDIO20_AD_CTRL_MODE = 0x01,
+  AUDIO20_AD_CTRL_DYN_RANGE = 0x02,
+  AUDIO20_AD_CTRL_SCALING = 0x03,
+  AUDIO20_AD_CTRL_HILO_SCALING = 0x04,
+  AUDIO20_AD_CTRL_UNDERFLOW = 0x05,
+  AUDIO20_AD_CTRL_OVERFLOW = 0x06,
+  AUDIO20_AD_CTRL_DECODER_ERROR = 0x07,
+} audio20_AC3_decoder_control_selector_t;
 
 /// A.17.13.3 WMA Decoder Control Selectors
-typedef enum
-{
-  AUDIO_WD_CTRL_UNDEF                         = 0x00,
-  AUDIO_WD_CTRL_UNDERFLOW                     = 0x01,
-  AUDIO_WD_CTRL_OVERFLOW                      = 0x02,
-  AUDIO_WD_CTRL_DECODER_ERROR                 = 0x03,
-} audio_WMA_decoder_control_selector_t;
+typedef enum {
+  AUDIO20_WD_CTRL_UNDEF = 0x00,
+  AUDIO20_WD_CTRL_UNDERFLOW = 0x01,
+  AUDIO20_WD_CTRL_OVERFLOW = 0x02,
+  AUDIO20_WD_CTRL_DECODER_ERROR = 0x03,
+} audio20_WMA_decoder_control_selector_t;
 
 /// A.17.13.4 DTS Decoder Control Selectors
-typedef enum
-{
-  AUDIO_DD_CTRL_UNDEF                         = 0x00,
-  AUDIO_DD_CTRL_UNDERFLOW                     = 0x01,
-  AUDIO_DD_CTRL_OVERFLOW                      = 0x02,
-  AUDIO_DD_CTRL_DECODER_ERROR                 = 0x03,
-} audio_DTS_decoder_control_selector_t;
+typedef enum {
+  AUDIO20_DD_CTRL_UNDEF = 0x00,
+  AUDIO20_DD_CTRL_UNDERFLOW = 0x01,
+  AUDIO20_DD_CTRL_OVERFLOW = 0x02,
+  AUDIO20_DD_CTRL_DECODER_ERROR = 0x03,
+} audio20_DTS_decoder_control_selector_t;
 
 /// A.17.14 Endpoint Control Selectors
-typedef enum
-{
-  AUDIO_EP_CTRL_UNDEF                         = 0x00,
-  AUDIO_EP_CTRL_PITCH                         = 0x01,
-  AUDIO_EP_CTRL_DATA_OVERRUN                  = 0x02,
-  AUDIO_EP_CTRL_DATA_UNDERRUN                 = 0x03,
-} audio_EP_control_selector_t;
-
-/// Terminal Types
-
-/// 2.1 - Audio Class-Terminal Types UAC2
-typedef enum
-{
-  AUDIO_TERM_TYPE_USB_UNDEFINED       = 0x0100,
-  AUDIO_TERM_TYPE_USB_STREAMING       = 0x0101,
-  AUDIO_TERM_TYPE_USB_VENDOR_SPEC     = 0x01FF,
-} audio_terminal_type_t;
-
-/// 2.2 - Audio Class-Input Terminal Types UAC2
-typedef enum
-{
-  AUDIO_TERM_TYPE_IN_UNDEFINED        = 0x0200,
-  AUDIO_TERM_TYPE_IN_GENERIC_MIC      = 0x0201,
-  AUDIO_TERM_TYPE_IN_DESKTOP_MIC      = 0x0202,
-  AUDIO_TERM_TYPE_IN_PERSONAL_MIC     = 0x0203,
-  AUDIO_TERM_TYPE_IN_OMNI_MIC         = 0x0204,
-  AUDIO_TERM_TYPE_IN_ARRAY_MIC        = 0x0205,
-  AUDIO_TERM_TYPE_IN_PROC_ARRAY_MIC   = 0x0206,
-} audio_terminal_input_type_t;
-
-/// 2.3 - Audio Class-Output Terminal Types UAC2
-typedef enum
-{
-  AUDIO_TERM_TYPE_OUT_UNDEFINED               = 0x0300,
-  AUDIO_TERM_TYPE_OUT_GENERIC_SPEAKER         = 0x0301,
-  AUDIO_TERM_TYPE_OUT_HEADPHONES              = 0x0302,
-  AUDIO_TERM_TYPE_OUT_HEAD_MNT_DISP_AUIDO     = 0x0303,
-  AUDIO_TERM_TYPE_OUT_DESKTOP_SPEAKER         = 0x0304,
-  AUDIO_TERM_TYPE_OUT_ROOM_SPEAKER            = 0x0305,
-  AUDIO_TERM_TYPE_OUT_COMMUNICATION_SPEAKER   = 0x0306,
-  AUDIO_TERM_TYPE_OUT_LOW_FRQ_EFFECTS_SPEAKER = 0x0307,
-} audio_terminal_output_type_t;
-
-/// Rest is yet to be implemented
+typedef enum {
+  AUDIO20_EP_CTRL_UNDEF = 0x00,
+  AUDIO20_EP_CTRL_PITCH = 0x01,
+  AUDIO20_EP_CTRL_DATA_OVERRUN = 0x02,
+  AUDIO20_EP_CTRL_DATA_UNDERRUN = 0x03,
+} audio20_EP_control_selector_t;
 
 /// Additional Audio Device Class Codes - Source: Audio Data Formats
 
 /// A.1 - Audio Class-Format Type Codes UAC2
-typedef enum
-{
-  AUDIO_FORMAT_TYPE_UNDEFINED     = 0x00,
-  AUDIO_FORMAT_TYPE_I             = 0x01,
-  AUDIO_FORMAT_TYPE_II            = 0x02,
-  AUDIO_FORMAT_TYPE_III           = 0x03,
-  AUDIO_FORMAT_TYPE_IV            = 0x04,
-  AUDIO_EXT_FORMAT_TYPE_I         = 0x81,
-  AUDIO_EXT_FORMAT_TYPE_II        = 0x82,
-  AUDIO_EXT_FORMAT_TYPE_III       = 0x83,
-} audio_format_type_t;
+typedef enum {
+  AUDIO20_FORMAT_TYPE_UNDEFINED = 0x00,
+  AUDIO20_FORMAT_TYPE_I = 0x01,
+  AUDIO20_FORMAT_TYPE_II = 0x02,
+  AUDIO20_FORMAT_TYPE_III = 0x03,
+  AUDIO20_FORMAT_TYPE_IV = 0x04,
+  AUDIO20_EXT_FORMAT_TYPE_I = 0x81,
+  AUDIO20_EXT_FORMAT_TYPE_II = 0x82,
+  AUDIO20_EXT_FORMAT_TYPE_III = 0x83,
+} audio20_format_type_t;
 
 // A.2.1 - Audio Class-Audio Data Format Type I UAC2
-typedef enum
-{
-  AUDIO_DATA_FORMAT_TYPE_I_PCM            = (uint32_t) (1 << 0),
-  AUDIO_DATA_FORMAT_TYPE_I_PCM8           = (uint32_t) (1 << 1),
-  AUDIO_DATA_FORMAT_TYPE_I_IEEE_FLOAT     = (uint32_t) (1 << 2),
-  AUDIO_DATA_FORMAT_TYPE_I_ALAW           = (uint32_t) (1 << 3),
-  AUDIO_DATA_FORMAT_TYPE_I_MULAW          = (uint32_t) (1 << 4),
-  AUDIO_DATA_FORMAT_TYPE_I_RAW_DATA       = 0x80000000u,
-} audio_data_format_type_I_t;
+typedef enum {
+  AUDIO20_DATA_FORMAT_TYPE_I_PCM = 1 << 0,
+  AUDIO20_DATA_FORMAT_TYPE_I_PCM8 = 1 << 1,
+  AUDIO20_DATA_FORMAT_TYPE_I_IEEE_FLOAT = 1 << 2,
+  AUDIO20_DATA_FORMAT_TYPE_I_ALAW = 1 << 3,
+  AUDIO20_DATA_FORMAT_TYPE_I_MULAW = 1 << 4,
+  AUDIO20_DATA_FORMAT_TYPE_I_RAW_DATA = 0x80000000u,
+} audio20_data_format_type_I_t;
+
+/// Audio Class-Audio Channel Configuration UAC2 (Table A-11)
+typedef enum {
+  AUDIO20_CHANNEL_CONFIG_NON_PREDEFINED = 0x00000000,
+  AUDIO20_CHANNEL_CONFIG_FRONT_LEFT = 0x00000001,
+  AUDIO20_CHANNEL_CONFIG_FRONT_RIGHT = 0x00000002,
+  AUDIO20_CHANNEL_CONFIG_FRONT_CENTER = 0x00000004,
+  AUDIO20_CHANNEL_CONFIG_LOW_FRQ_EFFECTS = 0x00000008,
+  AUDIO20_CHANNEL_CONFIG_BACK_LEFT = 0x00000010,
+  AUDIO20_CHANNEL_CONFIG_BACK_RIGHT = 0x00000020,
+  AUDIO20_CHANNEL_CONFIG_FRONT_LEFT_OF_CENTER = 0x00000040,
+  AUDIO20_CHANNEL_CONFIG_FRONT_RIGHT_OF_CENTER = 0x00000080,
+  AUDIO20_CHANNEL_CONFIG_BACK_CENTER = 0x00000100,
+  AUDIO20_CHANNEL_CONFIG_SIDE_LEFT = 0x00000200,
+  AUDIO20_CHANNEL_CONFIG_SIDE_RIGHT = 0x00000400,
+  AUDIO20_CHANNEL_CONFIG_TOP_CENTER = 0x00000800,
+  AUDIO20_CHANNEL_CONFIG_TOP_FRONT_LEFT = 0x00001000,
+  AUDIO20_CHANNEL_CONFIG_TOP_FRONT_CENTER = 0x00002000,
+  AUDIO20_CHANNEL_CONFIG_TOP_FRONT_RIGHT = 0x00004000,
+  AUDIO20_CHANNEL_CONFIG_TOP_BACK_LEFT = 0x00008000,
+  AUDIO20_CHANNEL_CONFIG_TOP_BACK_CENTER = 0x00010000,
+  AUDIO20_CHANNEL_CONFIG_TOP_BACK_RIGHT = 0x00020000,
+  AUDIO20_CHANNEL_CONFIG_TOP_FRONT_LEFT_OF_CENTER = 0x00040000,
+  AUDIO20_CHANNEL_CONFIG_TOP_FRONT_RIGHT_OF_CENTER = 0x00080000,
+  AUDIO20_CHANNEL_CONFIG_LEFT_LOW_FRQ_EFFECTS = 0x00100000,
+  AUDIO20_CHANNEL_CONFIG_RIGHT_LOW_FRQ_EFFECTS = 0x00200000,
+  AUDIO20_CHANNEL_CONFIG_TOP_SIDE_LEFT = 0x00400000,
+  AUDIO20_CHANNEL_CONFIG_TOP_SIDE_RIGHT = 0x00800000,
+  AUDIO20_CHANNEL_CONFIG_BOTTOM_CENTER = 0x01000000,
+  AUDIO20_CHANNEL_CONFIG_BACK_LEFT_OF_CENTER = 0x02000000,
+  AUDIO20_CHANNEL_CONFIG_BACK_RIGHT_OF_CENTER = 0x04000000,
+  AUDIO20_CHANNEL_CONFIG_RAW_DATA = 0x80000000u,
+} audio20_channel_config_t;
 
 /// All remaining definitions are taken from the descriptor descriptions in the UAC2 main specification
 
 /// Audio Class-Control Values UAC2
-typedef enum
-{
-  AUDIO_CTRL_NONE     = 0x00,         ///< No Host access
-  AUDIO_CTRL_R        = 0x01,         ///< Host read access only
-  AUDIO_CTRL_RW       = 0x03,         ///< Host read write access
-} audio_control_t;
+typedef enum {
+  AUDIO20_CTRL_NONE = 0x00,///< No Host access
+  AUDIO20_CTRL_R = 0x01,   ///< Host read access only
+  AUDIO20_CTRL_RW = 0x03,  ///< Host read write access
+} audio20_control_t;
 
 /// Audio Class-Specific AC Interface Descriptor Controls UAC2
-typedef enum
-{
-  AUDIO_CS_AS_INTERFACE_CTRL_LATENCY_POS  = 0,
-} audio_cs_ac_interface_control_pos_t;
+typedef enum {
+  AUDIO20_CS_AS_INTERFACE_CTRL_LATENCY_POS = 0,
+} audio20_cs_ac_interface_control_pos_t;
 
 /// Audio Class-Specific AS Interface Descriptor Controls UAC2
-typedef enum
-{
-  AUDIO_CS_AS_INTERFACE_CTRL_ACTIVE_ALT_SET_POS   = 0,
-  AUDIO_CS_AS_INTERFACE_CTRL_VALID_ALT_SET_POS    = 2,
-} audio_cs_as_interface_control_pos_t;
+typedef enum {
+  AUDIO20_CS_AS_INTERFACE_CTRL_ACTIVE_ALT_SET_POS = 0,
+  AUDIO20_CS_AS_INTERFACE_CTRL_VALID_ALT_SET_POS = 2,
+} audio20_cs_as_interface_control_pos_t;
 
 /// Audio Class-Specific AS Isochronous Data EP Attributes UAC2
-typedef enum
-{
-  AUDIO_CS_AS_ISO_DATA_EP_ATT_MAX_PACKETS_ONLY    = 0x80,
-  AUDIO_CS_AS_ISO_DATA_EP_ATT_NON_MAX_PACKETS_OK  = 0x00,
-} audio_cs_as_iso_data_ep_attribute_t;
+typedef enum {
+  AUDIO20_CS_AS_ISO_DATA_EP_ATT_MAX_PACKETS_ONLY = 0x80,
+  AUDIO20_CS_AS_ISO_DATA_EP_ATT_NON_MAX_PACKETS_OK = 0x00,
+} audio20_cs_as_iso_data_ep_attribute_t;
 
 /// Audio Class-Specific AS Isochronous Data EP Controls UAC2
-typedef enum
-{
-  AUDIO_CS_AS_ISO_DATA_EP_CTRL_PITCH_POS          = 0,
-  AUDIO_CS_AS_ISO_DATA_EP_CTRL_DATA_OVERRUN_POS   = 2,
-  AUDIO_CS_AS_ISO_DATA_EP_CTRL_DATA_UNDERRUN_POS  = 4,
-} audio_cs_as_iso_data_ep_control_pos_t;
+typedef enum {
+  AUDIO20_CS_AS_ISO_DATA_EP_CTRL_PITCH_POS = 0,
+  AUDIO20_CS_AS_ISO_DATA_EP_CTRL_DATA_OVERRUN_POS = 2,
+  AUDIO20_CS_AS_ISO_DATA_EP_CTRL_DATA_UNDERRUN_POS = 4,
+} audio20_cs_as_iso_data_ep_control_pos_t;
 
 /// Audio Class-Specific AS Isochronous Data EP Lock Delay Units UAC2
-typedef enum
-{
-  AUDIO_CS_AS_ISO_DATA_EP_LOCK_DELAY_UNIT_UNDEFINED       = 0x00,
-  AUDIO_CS_AS_ISO_DATA_EP_LOCK_DELAY_UNIT_MILLISEC        = 0x01,
-  AUDIO_CS_AS_ISO_DATA_EP_LOCK_DELAY_UNIT_PCM_SAMPLES     = 0x02,
-} audio_cs_as_iso_data_ep_lock_delay_unit_t;
+typedef enum {
+  AUDIO20_CS_AS_ISO_DATA_EP_LOCK_DELAY_UNIT_UNDEFINED = 0x00,
+  AUDIO20_CS_AS_ISO_DATA_EP_LOCK_DELAY_UNIT_MILLISEC = 0x01,
+  AUDIO20_CS_AS_ISO_DATA_EP_LOCK_DELAY_UNIT_PCM_SAMPLES = 0x02,
+} audio20_cs_as_iso_data_ep_lock_delay_unit_t;
 
 /// Audio Class-Clock Source Attributes UAC2
-typedef enum
-{
-  AUDIO_CLOCK_SOURCE_ATT_EXT_CLK      = 0x00,
-  AUDIO_CLOCK_SOURCE_ATT_INT_FIX_CLK  = 0x01,
-  AUDIO_CLOCK_SOURCE_ATT_INT_VAR_CLK  = 0x02,
-  AUDIO_CLOCK_SOURCE_ATT_INT_PRO_CLK  = 0x03,
-  AUDIO_CLOCK_SOURCE_ATT_CLK_SYC_SOF  = 0x04,
-} audio_clock_source_attribute_t;
+typedef enum {
+  AUDIO20_CLOCK_SOURCE_ATT_EXT_CLK = 0x00,
+  AUDIO20_CLOCK_SOURCE_ATT_INT_FIX_CLK = 0x01,
+  AUDIO20_CLOCK_SOURCE_ATT_INT_VAR_CLK = 0x02,
+  AUDIO20_CLOCK_SOURCE_ATT_INT_PRO_CLK = 0x03,
+  AUDIO20_CLOCK_SOURCE_ATT_CLK_SYC_SOF = 0x04,
+} audio20_clock_source_attribute_t;
 
 /// Audio Class-Clock Source Controls UAC2
-typedef enum
-{
-  AUDIO_CLOCK_SOURCE_CTRL_CLK_FRQ_POS     = 0,
-  AUDIO_CLOCK_SOURCE_CTRL_CLK_VAL_POS     = 2,
-} audio_clock_source_control_pos_t;
+typedef enum {
+  AUDIO20_CLOCK_SOURCE_CTRL_CLK_FRQ_POS = 0,
+  AUDIO20_CLOCK_SOURCE_CTRL_CLK_VAL_POS = 2,
+} audio20_clock_source_control_pos_t;
 
 /// Audio Class-Clock Selector Controls UAC2
-typedef enum
-{
-  AUDIO_CLOCK_SELECTOR_CTRL_POS   = 0,
-} audio_clock_selector_control_pos_t;
+typedef enum {
+  AUDIO20_CLOCK_SELECTOR_CTRL_POS = 0,
+} audio20_clock_selector_control_pos_t;
 
 /// Audio Class-Clock Multiplier Controls UAC2
-typedef enum
-{
-  AUDIO_CLOCK_MULTIPLIER_CTRL_NUMERATOR_POS       = 0,
-  AUDIO_CLOCK_MULTIPLIER_CTRL_DENOMINATOR_POS     = 2,
-} audio_clock_multiplier_control_pos_t;
+typedef enum {
+  AUDIO20_CLOCK_MULTIPLIER_CTRL_NUMERATOR_POS = 0,
+  AUDIO20_CLOCK_MULTIPLIER_CTRL_DENOMINATOR_POS = 2,
+} audio20_clock_multiplier_control_pos_t;
 
 /// Audio Class-Input Terminal Controls UAC2
-typedef enum
-{
-  AUDIO_IN_TERM_CTRL_CPY_PROT_POS     = 0,
-  AUDIO_IN_TERM_CTRL_CONNECTOR_POS    = 2,
-  AUDIO_IN_TERM_CTRL_OVERLOAD_POS     = 4,
-  AUDIO_IN_TERM_CTRL_CLUSTER_POS      = 6,
-  AUDIO_IN_TERM_CTRL_UNDERFLOW_POS    = 8,
-  AUDIO_IN_TERM_CTRL_OVERFLOW_POS     = 10,
-} audio_terminal_input_control_pos_t;
+typedef enum {
+  AUDIO20_IN_TERM_CTRL_CPY_PROT_POS = 0,
+  AUDIO20_IN_TERM_CTRL_CONNECTOR_POS = 2,
+  AUDIO20_IN_TERM_CTRL_OVERLOAD_POS = 4,
+  AUDIO20_IN_TERM_CTRL_CLUSTER_POS = 6,
+  AUDIO20_IN_TERM_CTRL_UNDERFLOW_POS = 8,
+  AUDIO20_IN_TERM_CTRL_OVERFLOW_POS = 10,
+} audio20_terminal_input_control_pos_t;
 
 /// Audio Class-Output Terminal Controls UAC2
-typedef enum
-{
-  AUDIO_OUT_TERM_CTRL_CPY_PROT_POS    = 0,
-  AUDIO_OUT_TERM_CTRL_CONNECTOR_POS   = 2,
-  AUDIO_OUT_TERM_CTRL_OVERLOAD_POS    = 4,
-  AUDIO_OUT_TERM_CTRL_UNDERFLOW_POS   = 6,
-  AUDIO_OUT_TERM_CTRL_OVERFLOW_POS    = 8,
-} audio_terminal_output_control_pos_t;
+typedef enum {
+  AUDIO20_OUT_TERM_CTRL_CPY_PROT_POS = 0,
+  AUDIO20_OUT_TERM_CTRL_CONNECTOR_POS = 2,
+  AUDIO20_OUT_TERM_CTRL_OVERLOAD_POS = 4,
+  AUDIO20_OUT_TERM_CTRL_UNDERFLOW_POS = 6,
+  AUDIO20_OUT_TERM_CTRL_OVERFLOW_POS = 8,
+} audio20_terminal_output_control_pos_t;
 
 /// Audio Class-Feature Unit Controls UAC2
-typedef enum
-{
-  AUDIO_FEATURE_UNIT_CTRL_MUTE_POS            = 0,
-  AUDIO_FEATURE_UNIT_CTRL_VOLUME_POS          = 2,
-  AUDIO_FEATURE_UNIT_CTRL_BASS_POS            = 4,
-  AUDIO_FEATURE_UNIT_CTRL_MID_POS             = 6,
-  AUDIO_FEATURE_UNIT_CTRL_TREBLE_POS          = 8,
-  AUDIO_FEATURE_UNIT_CTRL_GRAPHIC_EQU_POS     = 10,
-  AUDIO_FEATURE_UNIT_CTRL_AGC_POS             = 12,
-  AUDIO_FEATURE_UNIT_CTRL_DELAY_POS           = 14,
-  AUDIO_FEATURE_UNIT_CTRL_BASS_BOOST_POS      = 16,
-  AUDIO_FEATURE_UNIT_CTRL_LOUDNESS_POS        = 18,
-  AUDIO_FEATURE_UNIT_CTRL_INPUT_GAIN_POS      = 20,
-  AUDIO_FEATURE_UNIT_CTRL_INPUT_GAIN_PAD_POS  = 22,
-  AUDIO_FEATURE_UNIT_CTRL_PHASE_INV_POS       = 24,
-  AUDIO_FEATURE_UNIT_CTRL_UNDERFLOW_POS       = 26,
-  AUDIO_FEATURE_UNIT_CTRL_OVERFLOW_POS        = 28,
-} audio_feature_unit_control_pos_t;
+typedef enum {
+  AUDIO20_FEATURE_UNIT_CTRL_MUTE_POS = 0,
+  AUDIO20_FEATURE_UNIT_CTRL_VOLUME_POS = 2,
+  AUDIO20_FEATURE_UNIT_CTRL_BASS_POS = 4,
+  AUDIO20_FEATURE_UNIT_CTRL_MID_POS = 6,
+  AUDIO20_FEATURE_UNIT_CTRL_TREBLE_POS = 8,
+  AUDIO20_FEATURE_UNIT_CTRL_GRAPHIC_EQU_POS = 10,
+  AUDIO20_FEATURE_UNIT_CTRL_AGC_POS = 12,
+  AUDIO20_FEATURE_UNIT_CTRL_DELAY_POS = 14,
+  AUDIO20_FEATURE_UNIT_CTRL_BASS_BOOST_POS = 16,
+  AUDIO20_FEATURE_UNIT_CTRL_LOUDNESS_POS = 18,
+  AUDIO20_FEATURE_UNIT_CTRL_INPUT_GAIN_POS = 20,
+  AUDIO20_FEATURE_UNIT_CTRL_INPUT_GAIN_PAD_POS = 22,
+  AUDIO20_FEATURE_UNIT_CTRL_PHASE_INV_POS = 24,
+  AUDIO20_FEATURE_UNIT_CTRL_UNDERFLOW_POS = 26,
+  AUDIO20_FEATURE_UNIT_CTRL_OVERFLOW_POS = 28,
+} audio20_feature_unit_control_pos_t;
 
-/// Audio Class-Audio Channel Configuration UAC2
-typedef enum
-{
-  AUDIO_CHANNEL_CONFIG_NON_PREDEFINED             = 0x00000000,
-  AUDIO_CHANNEL_CONFIG_FRONT_LEFT                 = 0x00000001,
-  AUDIO_CHANNEL_CONFIG_FRONT_RIGHT                = 0x00000002,
-  AUDIO_CHANNEL_CONFIG_FRONT_CENTER               = 0x00000004,
-  AUDIO_CHANNEL_CONFIG_LOW_FRQ_EFFECTS            = 0x00000008,
-  AUDIO_CHANNEL_CONFIG_BACK_LEFT                  = 0x00000010,
-  AUDIO_CHANNEL_CONFIG_BACK_RIGHT                 = 0x00000020,
-  AUDIO_CHANNEL_CONFIG_FRONT_LEFT_OF_CENTER       = 0x00000040,
-  AUDIO_CHANNEL_CONFIG_FRONT_RIGHT_OF_CENTER      = 0x00000080,
-  AUDIO_CHANNEL_CONFIG_BACK_CENTER                = 0x00000100,
-  AUDIO_CHANNEL_CONFIG_SIDE_LEFT                  = 0x00000200,
-  AUDIO_CHANNEL_CONFIG_SIDE_RIGHT                 = 0x00000400,
-  AUDIO_CHANNEL_CONFIG_TOP_CENTER                 = 0x00000800,
-  AUDIO_CHANNEL_CONFIG_TOP_FRONT_LEFT             = 0x00001000,
-  AUDIO_CHANNEL_CONFIG_TOP_FRONT_CENTER           = 0x00002000,
-  AUDIO_CHANNEL_CONFIG_TOP_FRONT_RIGHT            = 0x00004000,
-  AUDIO_CHANNEL_CONFIG_TOP_BACK_LEFT              = 0x00008000,
-  AUDIO_CHANNEL_CONFIG_TOP_BACK_CENTER            = 0x00010000,
-  AUDIO_CHANNEL_CONFIG_TOP_BACK_RIGHT             = 0x00020000,
-  AUDIO_CHANNEL_CONFIG_TOP_FRONT_LEFT_OF_CENTER   = 0x00040000,
-  AUDIO_CHANNEL_CONFIG_TOP_FRONT_RIGHT_OF_CENTER  = 0x00080000,
-  AUDIO_CHANNEL_CONFIG_LEFT_LOW_FRQ_EFFECTS       = 0x00100000,
-  AUDIO_CHANNEL_CONFIG_RIGHT_LOW_FRQ_EFFECTS      = 0x00200000,
-  AUDIO_CHANNEL_CONFIG_TOP_SIDE_LEFT              = 0x00400000,
-  AUDIO_CHANNEL_CONFIG_TOP_SIDE_RIGHT             = 0x00800000,
-  AUDIO_CHANNEL_CONFIG_BOTTOM_CENTER              = 0x01000000,
-  AUDIO_CHANNEL_CONFIG_BACK_LEFT_OF_CENTER        = 0x02000000,
-  AUDIO_CHANNEL_CONFIG_BACK_RIGHT_OF_CENTER       = 0x04000000,
-  AUDIO_CHANNEL_CONFIG_RAW_DATA                   = 0x80000000u,
-} audio_channel_config_t;
+//--------------------------------------------------------------------+
+// USB AUDIO CLASS 2.0 (UAC2) DESCRIPTORS
+//--------------------------------------------------------------------+
 
-/// AUDIO Channel Cluster Descriptor (4.1)
+/// AUDIO Channel Cluster Descriptor UAC2 (4.1)
 typedef struct TU_ATTR_PACKED {
-  uint8_t                 bNrChannels;        ///< Number of channels currently connected.
-  audio_channel_config_t  bmChannelConfig;    ///< Bitmap according to 'audio_channel_config_t' with a 1 set if channel is connected and 0 else. In case channels are non-predefined ignore them here (see UAC2 specification 4.1 Audio Channel Cluster Descriptor.
-  uint8_t                 iChannelNames;      ///< Index of a string descriptor, describing the name of the first inserted channel with a non-predefined spatial location.
-} audio_desc_channel_cluster_t;
+  uint8_t bNrChannels;                     ///< Number of channels currently connected.
+  uint32_t bmChannelConfig;///< Bitmap according to 'audio20_channel_config_t' with a 1 set if channel is connected and 0 else. In case channels are non-predefined ignore them here (see UAC2 specification 4.1 Audio Channel Cluster Descriptor.
+  uint8_t iChannelNames;                   ///< Index of a string descriptor, describing the name of the first inserted channel with a non-predefined spatial location.
+} audio20_desc_channel_cluster_t;
 
-/// AUDIO Class-Specific AC Interface Header Descriptor (4.7.2)
-typedef struct TU_ATTR_PACKED
-{
-  uint8_t bLength            ; ///< Size of this descriptor in bytes: 9.
-  uint8_t bDescriptorType    ; ///< Descriptor Type. Value: TUSB_DESC_CS_INTERFACE.
-  uint8_t bDescriptorSubType ; ///< Descriptor SubType. Value: AUDIO_CS_AC_INTERFACE_HEADER.
-  uint16_t bcdADC            ; ///< Audio Device Class Specification Release Number in Binary-Coded Decimal. Value: U16_TO_U8S_LE(0x0200).
-  uint8_t bCategory          ; ///< Constant, indicating the primary use of this audio function, as intended by the manufacturer. See: audio_function_t.
-  uint16_t wTotalLength      ; ///< Total number of bytes returned for the class-specific AudioControl interface descriptor. Includes the combined length of this descriptor header and all Clock Source, Unit and Terminal descriptors.
-  uint8_t bmControls         ; ///< See: audio_cs_ac_interface_control_pos_t.
-} audio_desc_cs_ac_interface_t;
-TU_VERIFY_STATIC(sizeof(audio_desc_cs_ac_interface_t) == 9, "size is not correct");
+/// AUDIO Class-Specific AC Interface Header Descriptor UAC2 (4.7.2)
+typedef struct TU_ATTR_PACKED {
+  uint8_t bLength;           ///< Size of this descriptor in bytes: 9.
+  uint8_t bDescriptorType;   ///< Descriptor Type. Value: TUSB_DESC_CS_INTERFACE.
+  uint8_t bDescriptorSubType;///< Descriptor SubType. Value: AUDIO20_CS_AC_INTERFACE_HEADER.
+  uint16_t bcdADC;           ///< Audio Device Class Specification Release Number in Binary-Coded Decimal. Value: U16_TO_U8S_LE(0x0200).
+  uint8_t bCategory;         ///< Constant, indicating the primary use of this audio function, as intended by the manufacturer. See: audio20_function_code_t.
+  uint16_t wTotalLength;     ///< Total number of bytes returned for the class-specific AudioControl interface descriptor. Includes the combined length of this descriptor header and all Clock Source, Unit and Terminal descriptors.
+  uint8_t bmControls;        ///< See: audio20_cs_ac_interface_control_pos_t.
+} audio20_desc_cs_ac_interface_t;
+TU_VERIFY_STATIC(sizeof(audio20_desc_cs_ac_interface_t) == 9, "size is not correct");
 
-/// AUDIO Clock Source Descriptor (4.7.2.1)
-typedef struct TU_ATTR_PACKED
-{
-  uint8_t bLength            ; ///< Size of this descriptor in bytes: 8.
-  uint8_t bDescriptorType    ; ///< Descriptor Type. Value: TUSB_DESC_CS_INTERFACE.
-  uint8_t bDescriptorSubType ; ///< Descriptor SubType. Value: AUDIO_CS_AC_INTERFACE_CLOCK_SOURCE.
-  uint8_t bClockID           ; ///< Constant uniquely identifying the Clock Source Entity within the audio function. This value is used in all requests to address this Entity.
-  uint8_t bmAttributes       ; ///< See: audio_clock_source_attribute_t.
-  uint8_t bmControls         ; ///< See: audio_clock_source_control_pos_t.
-  uint8_t bAssocTerminal     ; ///< Terminal ID of the Terminal that is associated with this Clock Source.
-  uint8_t iClockSource       ; ///< Index of a string descriptor, describing the Clock Source Entity.
-} audio_desc_clock_source_t;
+/// AUDIO Clock Source Descriptor UAC2 (4.7.2.1)
+typedef struct TU_ATTR_PACKED {
+  uint8_t bLength;           ///< Size of this descriptor in bytes: 8.
+  uint8_t bDescriptorType;   ///< Descriptor Type. Value: TUSB_DESC_CS_INTERFACE.
+  uint8_t bDescriptorSubType;///< Descriptor SubType. Value: AUDIO20_CS_AC_INTERFACE_CLOCK_SOURCE.
+  uint8_t bClockID;          ///< Constant uniquely identifying the Clock Source Entity within the audio function. This value is used in all requests to address this Entity.
+  uint8_t bmAttributes;      ///< See: audio20_clock_source_attribute_t.
+  uint8_t bmControls;        ///< See: audio20_clock_source_control_pos_t.
+  uint8_t bAssocTerminal;    ///< Terminal ID of the Terminal that is associated with this Clock Source.
+  uint8_t iClockSource;      ///< Index of a string descriptor, describing the Clock Source Entity.
+} audio20_desc_clock_source_t;
 
-/// AUDIO Clock Selector Descriptor (4.7.2.2) for ONE pin
-typedef struct TU_ATTR_PACKED
-{
-  uint8_t bLength            ; ///< Size of this descriptor, in bytes: 7+p.
-  uint8_t bDescriptorType    ; ///< Descriptor Type. Value: TUSB_DESC_CS_INTERFACE.
-  uint8_t bDescriptorSubType ; ///< Descriptor SubType. Value: AUDIO_CS_AC_INTERFACE_CLOCK_SELECTOR.
-  uint8_t bClockID           ; ///< Constant uniquely identifying the Clock Selector Entity within the audio function. This value is used in all requests to address this Entity.
-  uint8_t bNrInPins          ; ///< Number of Input Pins of this Unit: p = 1 thus bNrInPins = 1.
-  uint8_t baCSourceID        ; ///< ID of the Clock Entity to which the first Clock Input Pin of this Clock Selector Entity is connected..
-  uint8_t bmControls         ; ///< See: audio_clock_selector_control_pos_t.
-  uint8_t iClockSource       ; ///< Index of a string descriptor, describing the Clock Selector Entity.
-} audio_desc_clock_selector_t;
+/// AUDIO Clock Selector Descriptor UAC2 (4.7.2.2) for ONE pin
+typedef struct TU_ATTR_PACKED {
+  uint8_t bLength;           ///< Size of this descriptor, in bytes: 7+p.
+  uint8_t bDescriptorType;   ///< Descriptor Type. Value: TUSB_DESC_CS_INTERFACE.
+  uint8_t bDescriptorSubType;///< Descriptor SubType. Value: AUDIO20_CS_AC_INTERFACE_CLOCK_SELECTOR.
+  uint8_t bClockID;          ///< Constant uniquely identifying the Clock Selector Entity within the audio function. This value is used in all requests to address this Entity.
+  uint8_t bNrInPins;         ///< Number of Input Pins of this Unit: p = 1 thus bNrInPins = 1.
+  uint8_t baCSourceID;       ///< ID of the Clock Entity to which the first Clock Input Pin of this Clock Selector Entity is connected..
+  uint8_t bmControls;        ///< See: audio20_clock_selector_control_pos_t.
+  uint8_t iClockSource;      ///< Index of a string descriptor, describing the Clock Selector Entity.
+} audio20_desc_clock_selector_t;
 
 /// AUDIO Clock Selector Descriptor (4.7.2.2) for multiple pins
-#define audio_desc_clock_selector_n_t(source_num) \
-    struct TU_ATTR_PACKED {       \
-  uint8_t bLength               ; \
-  uint8_t bDescriptorType       ; \
-  uint8_t bDescriptorSubType    ; \
-  uint8_t bClockID              ; \
-  uint8_t bNrInPins             ; \
-  struct TU_ATTR_PACKED {         \
-    uint8_t baSourceID          ; \
-  } sourceID[source_num]        ; \
-  uint8_t bmControls            ; \
-  uint8_t iClockSource          ; \
-}
+#define audio20_desc_clock_selector_n_t(source_num) \
+  struct TU_ATTR_PACKED {                           \
+    uint8_t bLength;                                \
+    uint8_t bDescriptorType;                        \
+    uint8_t bDescriptorSubType;                     \
+    uint8_t bClockID;                               \
+    uint8_t bNrInPins;                              \
+    struct TU_ATTR_PACKED {                         \
+      uint8_t baSourceID;                           \
+    } sourceID[source_num];                         \
+    uint8_t bmControls;                             \
+    uint8_t iClockSource;                           \
+  }
 
-/// AUDIO Clock Multiplier Descriptor (4.7.2.3)
-typedef struct TU_ATTR_PACKED
-{
-  uint8_t bLength            ; ///< Size of this descriptor, in bytes: 7.
-  uint8_t bDescriptorType    ; ///< Descriptor Type. Value: TUSB_DESC_CS_INTERFACE.
-  uint8_t bDescriptorSubType ; ///< Descriptor SubType. Value: AUDIO_CS_AC_INTERFACE_CLOCK_MULTIPLIER.
-  uint8_t bClockID           ; ///< Constant uniquely identifying the Clock Multiplier Entity within the audio function. This value is used in all requests to address this Entity.
-  uint8_t bCSourceID         ; ///< ID of the Clock Entity to which the last Clock Input Pin of this Clock Selector Entity is connected.
-  uint8_t bmControls         ; ///< See: audio_clock_multiplier_control_pos_t.
-  uint8_t iClockSource       ; ///< Index of a string descriptor, describing the Clock Multiplier Entity.
-} audio_desc_clock_multiplier_t;
+/// AUDIO Clock Multiplier Descriptor UAC2 (4.7.2.3)
+typedef struct TU_ATTR_PACKED {
+  uint8_t bLength;           ///< Size of this descriptor, in bytes: 7.
+  uint8_t bDescriptorType;   ///< Descriptor Type. Value: TUSB_DESC_CS_INTERFACE.
+  uint8_t bDescriptorSubType;///< Descriptor SubType. Value: AUDIO20_CS_AC_INTERFACE_CLOCK_MULTIPLIER.
+  uint8_t bClockID;          ///< Constant uniquely identifying the Clock Multiplier Entity within the audio function. This value is used in all requests to address this Entity.
+  uint8_t bCSourceID;        ///< ID of the Clock Entity to which the last Clock Input Pin of this Clock Selector Entity is connected.
+  uint8_t bmControls;        ///< See: audio20_clock_multiplier_control_pos_t.
+  uint8_t iClockSource;      ///< Index of a string descriptor, describing the Clock Multiplier Entity.
+} audio20_desc_clock_multiplier_t;
 
 /// AUDIO Input Terminal Descriptor(4.7.2.4)
-typedef struct TU_ATTR_PACKED
-{
-  uint8_t bLength            ; ///< Size of this descriptor, in bytes: 17.
-  uint8_t bDescriptorType    ; ///< Descriptor Type. Value: TUSB_DESC_CS_INTERFACE.
-  uint8_t bDescriptorSubType ; ///< Descriptor SubType. Value: AUDIO_CS_AC_INTERFACE_INPUT_TERMINAL.
-  uint8_t bTerminalID        ; ///< Constant uniquely identifying the Terminal within the audio function. This value is used in all requests to address this terminal.
-  uint16_t wTerminalType     ; ///< Constant characterizing the type of Terminal. See: audio_terminal_type_t for USB streaming and audio_terminal_input_type_t for other input types.
-  uint8_t bAssocTerminal     ; ///< ID of the Output Terminal to which this Input Terminal is associated.
-  uint8_t bCSourceID         ; ///< ID of the Clock Entity to which this Input Terminal is connected.
-  uint8_t bNrChannels        ; ///< Number of logical output channels in the Terminal’s output audio channel cluster.
-  uint32_t bmChannelConfig   ; ///< Describes the spatial location of the logical channels. See:audio_channel_config_t.
-  uint8_t iChannelNames      ; ///< Index of a string descriptor, describing the name of the first logical channel.
-  uint16_t bmControls        ; ///< See: audio_terminal_input_control_pos_t.
-  uint8_t iTerminal          ; ///< Index of a string descriptor, describing the Input Terminal.
-} audio_desc_input_terminal_t;
+typedef struct TU_ATTR_PACKED {
+  uint8_t bLength;           ///< Size of this descriptor, in bytes: 17.
+  uint8_t bDescriptorType;   ///< Descriptor Type. Value: TUSB_DESC_CS_INTERFACE.
+  uint8_t bDescriptorSubType;///< Descriptor SubType. Value: AUDIO_CS_AC_INTERFACE_INPUT_TERMINAL.
+  uint8_t bTerminalID;       ///< Constant uniquely identifying the Terminal within the audio function. This value is used in all requests to address this terminal.
+  uint16_t wTerminalType;    ///< Constant characterizing the type of Terminal. See: audio_terminal_type_t for USB streaming and audio_terminal_input_type_t for other input types.
+  uint8_t bAssocTerminal;    ///< ID of the Output Terminal to which this Input Terminal is associated.
+  uint8_t bCSourceID;        ///< ID of the Clock Entity to which this Input Terminal is connected.
+  uint8_t bNrChannels;       ///< Number of logical output channels in the Terminal’s output audio channel cluster.
+  uint32_t bmChannelConfig;  ///< Describes the spatial location of the logical channels. See:audio20_channel_config_t.
+  uint8_t iChannelNames;     ///< Index of a string descriptor, describing the name of the first logical channel.
+  uint16_t bmControls;       ///< See: audio_terminal_input_control_pos_t.
+  uint8_t iTerminal;         ///< Index of a string descriptor, describing the Input Terminal.
+} audio20_desc_input_terminal_t;
 
-/// AUDIO Output Terminal Descriptor(4.7.2.5)
-typedef struct TU_ATTR_PACKED
-{
-  uint8_t bLength            ; ///< Size of this descriptor, in bytes: 12.
-  uint8_t bDescriptorType    ; ///< Descriptor Type. Value: TUSB_DESC_CS_INTERFACE.
-  uint8_t bDescriptorSubType ; ///< Descriptor SubType. Value: AUDIO_CS_AC_INTERFACE_OUTPUT_TERMINAL.
-  uint8_t bTerminalID        ; ///< Constant uniquely identifying the Terminal within the audio function. This value is used in all requests to address this Terminal.
-  uint16_t wTerminalType     ; ///< Constant characterizing the type of Terminal. See: audio_terminal_type_t for USB streaming and audio_terminal_output_type_t for other output types.
-  uint8_t bAssocTerminal     ; ///< Constant, identifying the Input Terminal to which this Output Terminal is associated.
-  uint8_t bSourceID          ; ///< ID of the Unit or Terminal to which this Terminal is connected.
-  uint8_t bCSourceID         ; ///< ID of the Clock Entity to which this Output Terminal is connected.
-  uint16_t bmControls        ; ///< See: audio_terminal_output_type_t.
-  uint8_t iTerminal          ; ///< Index of a string descriptor, describing the Output Terminal.
-} audio_desc_output_terminal_t;
+/// AUDIO Output Terminal Descriptor UAC2 (4.7.2.5)
+typedef struct TU_ATTR_PACKED {
+  uint8_t bLength;           ///< Size of this descriptor, in bytes: 12.
+  uint8_t bDescriptorType;   ///< Descriptor Type. Value: TUSB_DESC_CS_INTERFACE.
+  uint8_t bDescriptorSubType;///< Descriptor SubType. Value: AUDIO20_CS_AC_INTERFACE_OUTPUT_TERMINAL.
+  uint8_t bTerminalID;       ///< Constant uniquely identifying the Terminal within the audio function. This value is used in all requests to address this Terminal.
+  uint16_t wTerminalType;    ///< Constant characterizing the type of Terminal. See: audio20_terminal_type_t for USB streaming and audio20_terminal_output_type_t for other output types.
+  uint8_t bAssocTerminal;    ///< Constant, identifying the Input Terminal to which this Output Terminal is associated.
+  uint8_t bSourceID;         ///< ID of the Unit or Terminal to which this Terminal is connected.
+  uint8_t bCSourceID;        ///< ID of the Clock Entity to which this Output Terminal is connected.
+  uint16_t bmControls;       ///< See: audio20_terminal_output_control_pos_t.
+  uint8_t iTerminal;         ///< Index of a string descriptor, describing the Output Terminal.
+} audio20_desc_output_terminal_t;
 
-/// AUDIO Feature Unit Descriptor(4.7.2.8) for ONE channel
-typedef struct TU_ATTR_PACKED
-{
-  uint8_t bLength            ; ///< Size of this descriptor, in bytes: 14.
-  uint8_t bDescriptorType    ; ///< Descriptor Type. Value: TUSB_DESC_CS_INTERFACE.
-  uint8_t bDescriptorSubType ; ///< Descriptor SubType. Value: AUDIO_CS_AC_INTERFACE_FEATURE_UNIT.
-  uint8_t bUnitID            ; ///< Constant uniquely identifying the Unit within the audio function. This value is used in all requests to address this Unit.
-  uint8_t bSourceID          ; ///< ID of the Unit or Terminal to which this Feature Unit is connected.
+/// AUDIO Feature Unit Descriptor UAC2 (4.7.2.8) for ONE channel
+typedef struct TU_ATTR_PACKED {
+  uint8_t bLength;           ///< Size of this descriptor, in bytes: 14.
+  uint8_t bDescriptorType;   ///< Descriptor Type. Value: TUSB_DESC_CS_INTERFACE.
+  uint8_t bDescriptorSubType;///< Descriptor SubType. Value: AUDIO20_CS_AC_INTERFACE_FEATURE_UNIT.
+  uint8_t bUnitID;           ///< Constant uniquely identifying the Unit within the audio function. This value is used in all requests to address this Unit.
+  uint8_t bSourceID;         ///< ID of the Unit or Terminal to which this Feature Unit is connected.
   struct TU_ATTR_PACKED {
-    uint32_t bmaControls     ; ///< See: audio_feature_unit_control_pos_t. Controls0 is master channel 0 (always present) and Controls1 is logical channel 1.
-  } controls[2]              ;
-  uint8_t iTerminal          ; ///< Index of a string descriptor, describing this Feature Unit.
-} audio_desc_feature_unit_t;
+    uint32_t bmaControls;///< See: audio20_feature_unit_control_pos_t. Controls0 is master channel 0 (always present) and Controls1 is logical channel 1.
+  } controls[2];
+  uint8_t iTerminal;///< Index of a string descriptor, describing this Feature Unit.
+} audio20_desc_feature_unit_t;
 
 /// AUDIO Feature Unit Descriptor(4.7.2.8) for multiple channels
-#define audio_desc_feature_unit_n_t(ch_num)\
-    struct TU_ATTR_PACKED {         \
-  uint8_t bLength               ; /* 6+(ch_num+1)*4 */\
-    uint8_t bDescriptorType     ; \
-    uint8_t bDescriptorSubType  ; \
-    uint8_t bUnitID             ; \
-    uint8_t bSourceID           ; \
-    struct TU_ATTR_PACKED {       \
-      uint32_t bmaControls      ; \
-    } controls[ch_num+1]        ; \
-    uint8_t iTerminal           ; \
-}
+#define audio20_desc_feature_unit_n_t(ch_num) \
+  struct TU_ATTR_PACKED {                     \
+    uint8_t bLength; /* 6+(ch_num+1)*4 */     \
+    uint8_t bDescriptorType;                  \
+    uint8_t bDescriptorSubType;               \
+    uint8_t bUnitID;                          \
+    uint8_t bSourceID;                        \
+    struct TU_ATTR_PACKED {                   \
+      uint32_t bmaControls;                   \
+    } controls[ch_num + 1];                   \
+    uint8_t iTerminal;                        \
+  }
 
 /// AUDIO Class-Specific AS Interface Descriptor(4.9.2)
-typedef struct TU_ATTR_PACKED
-{
-  uint8_t bLength            ; ///< Size of this descriptor, in bytes: 16.
-  uint8_t bDescriptorType    ; ///< Descriptor Type. Value: TUSB_DESC_CS_INTERFACE.
-  uint8_t bDescriptorSubType ; ///< Descriptor SubType. Value: AUDIO_CS_AS_INTERFACE_AS_GENERAL.
-  uint8_t bTerminalLink      ; ///< The Terminal ID of the Terminal to which this interface is connected.
-  uint8_t bmControls         ; ///< See: audio_cs_as_interface_control_pos_t.
-  uint8_t bFormatType        ; ///< Constant identifying the Format Type the AudioStreaming interface is using. See: audio_format_type_t.
-  uint32_t bmFormats         ; ///< The Audio Data Format(s) that can be used to communicate with this interface.See: audio_data_format_type_I_t.
-  uint8_t bNrChannels        ; ///< Number of physical channels in the AS Interface audio channel cluster.
-  uint32_t bmChannelConfig   ; ///< Describes the spatial location of the physical channels. See: audio_channel_config_t.
-  uint8_t iChannelNames      ; ///< Index of a string descriptor, describing the name of the first physical channel.
-} audio_desc_cs_as_interface_t;
+typedef struct TU_ATTR_PACKED {
+  uint8_t bLength;           ///< Size of this descriptor, in bytes: 16.
+  uint8_t bDescriptorType;   ///< Descriptor Type. Value: TUSB_DESC_CS_INTERFACE.
+  uint8_t bDescriptorSubType;///< Descriptor SubType. Value: AUDIO20_CS_AS_INTERFACE_AS_GENERAL.
+  uint8_t bTerminalLink;     ///< The Terminal ID of the Terminal to which this interface is connected.
+  uint8_t bmControls;        ///< See: audio20_cs_as_interface_control_pos_t.
+  uint8_t bFormatType;       ///< Constant identifying the Format Type the AudioStreaming interface is using. See: audio20_format_type_t.
+  uint32_t bmFormats;        ///< The Audio Data Format(s) that can be used to communicate with this interface.See: audio20_data_format_type_I_t.
+  uint8_t bNrChannels;       ///< Number of physical channels in the AS Interface audio channel cluster.
+  uint32_t bmChannelConfig;  ///< Describes the spatial location of the physical channels. See: audio20_channel_config_t.
+  uint8_t iChannelNames;     ///< Index of a string descriptor, describing the name of the first physical channel.
+} audio20_desc_cs_as_interface_t;
 
 /// AUDIO Type I Format Type Descriptor(2.3.1.6 - Audio Formats)
-typedef struct TU_ATTR_PACKED
-{
-  uint8_t bLength            ; ///< Size of this descriptor, in bytes: 6.
-  uint8_t bDescriptorType    ; ///< Descriptor Type. Value: TUSB_DESC_CS_INTERFACE.
-  uint8_t bDescriptorSubType ; ///< Descriptor SubType. Value: AUDIO_CS_AS_INTERFACE_FORMAT_TYPE.
-  uint8_t bFormatType        ; ///< Constant identifying the Format Type the AudioStreaming interface is using. Value: AUDIO_FORMAT_TYPE_I.
-  uint8_t bSubslotSize       ; ///< The number of bytes occupied by one audio subslot. Can be 1, 2, 3 or 4.
-  uint8_t bBitResolution     ; ///< The number of effectively used bits from the available bits in an audio subslot.
-} audio_desc_type_I_format_t;
+typedef struct TU_ATTR_PACKED {
+  uint8_t bLength;           ///< Size of this descriptor, in bytes: 6.
+  uint8_t bDescriptorType;   ///< Descriptor Type. Value: TUSB_DESC_CS_INTERFACE.
+  uint8_t bDescriptorSubType;///< Descriptor SubType. Value: AUDIO20_CS_AS_INTERFACE_FORMAT_TYPE.
+  uint8_t bFormatType;       ///< Constant identifying the Format Type the AudioStreaming interface is using. Value: AUDIO20_FORMAT_TYPE_I.
+  uint8_t bSubslotSize;      ///< The number of bytes occupied by one audio subslot. Can be 1, 2, 3 or 4.
+  uint8_t bBitResolution;    ///< The number of effectively used bits from the available bits in an audio subslot.
+} audio20_desc_type_I_format_t;
 
 /// AUDIO Class-Specific AS Isochronous Audio Data Endpoint Descriptor(4.10.1.2)
-typedef struct TU_ATTR_PACKED
-{
-  uint8_t bLength            ; ///< Size of this descriptor, in bytes: 8.
-  uint8_t bDescriptorType    ; ///< Descriptor Type. Value: TUSB_DESC_CS_ENDPOINT.
-  uint8_t bDescriptorSubType ; ///< Descriptor SubType. Value: AUDIO_CS_EP_SUBTYPE_GENERAL.
-  uint8_t bmAttributes       ; ///< See: audio_cs_as_iso_data_ep_attribute_t.
-  uint8_t bmControls         ; ///< See: audio_cs_as_iso_data_ep_control_pos_t.
-  uint8_t bLockDelayUnits    ; ///< Indicates the units used for the wLockDelay field. See: audio_cs_as_iso_data_ep_lock_delay_unit_t.
-  uint16_t wLockDelay        ; ///< Indicates the time it takes this endpoint to reliably lock its internal clock recovery circuitry. Units used depend on the value of the bLockDelayUnits field.
-} audio_desc_cs_as_iso_data_ep_t;
+typedef struct TU_ATTR_PACKED {
+  uint8_t bLength;           ///< Size of this descriptor, in bytes: 8.
+  uint8_t bDescriptorType;   ///< Descriptor Type. Value: TUSB_DESC_CS_ENDPOINT.
+  uint8_t bDescriptorSubType;///< Descriptor SubType. Value: AUDIO20_CS_EP_SUBTYPE_GENERAL.
+  uint8_t bmAttributes;      ///< See: audio20_cs_as_iso_data_ep_attribute_t.
+  uint8_t bmControls;        ///< See: audio20_cs_as_iso_data_ep_control_pos_t.
+  uint8_t bLockDelayUnits;   ///< Indicates the units used for the wLockDelay field. See: audio20_cs_as_iso_data_ep_lock_delay_unit_t.
+  uint16_t wLockDelay;       ///< Indicates the time it takes this endpoint to reliably lock its internal clock recovery circuitry. Units used depend on the value of the bLockDelayUnits field.
+} audio20_desc_cs_as_iso_data_ep_t;
 
 // 5.2.2 Control Request Layout
-typedef struct TU_ATTR_PACKED
-{
-    union
-    {
-        struct TU_ATTR_PACKED
-        {
-            uint8_t recipient :  5; ///< Recipient type tusb_request_recipient_t.
-            uint8_t type      :  2; ///< Request type tusb_request_type_t.
-            uint8_t direction :  1; ///< Direction type. tusb_dir_t
-        } bmRequestType_bit;
+typedef struct TU_ATTR_PACKED {
+  union {
+    struct TU_ATTR_PACKED {
+      uint8_t recipient : 5;///< Recipient type tusb_request_recipient_t.
+      uint8_t type : 2;     ///< Request type tusb_request_type_t.
+      uint8_t direction : 1;///< Direction type. tusb_dir_t
+    } bmRequestType_bit;
 
-        uint8_t bmRequestType;
-    };
+    uint8_t bmRequestType;
+  };
 
-    uint8_t bRequest;  ///< Request type audio_cs_req_t
-    uint8_t bChannelNumber;
-    uint8_t bControlSelector;
-    union
-    {
-        uint8_t bInterface;
-        uint8_t bEndpoint;
-    };
-    uint8_t bEntityID;
-    uint16_t wLength;
-} audio_control_request_t;
+  uint8_t bRequest;///< Request type audio_cs_req_t
+  uint8_t bChannelNumber;
+  uint8_t bControlSelector;
+  union {
+    uint8_t bInterface;
+    uint8_t bEndpoint;
+  };
+  uint8_t bEntityID;
+  uint16_t wLength;
+} audio20_control_request_t;
 
 //// 5.2.3 Control Request Parameter Block Layout
 
 // 5.2.3.1 1-byte Control CUR Parameter Block
-typedef struct TU_ATTR_PACKED
-{
-  int8_t bCur               ;   ///< The setting for the CUR attribute of the addressed Control
-} audio_control_cur_1_t;
+typedef struct TU_ATTR_PACKED {
+  int8_t bCur;///< The setting for the CUR attribute of the addressed Control
+} audio20_control_cur_1_t;
 
 // 5.2.3.2 2-byte Control CUR Parameter Block
-typedef struct TU_ATTR_PACKED
-{
-  int16_t bCur              ;   ///< The setting for the CUR attribute of the addressed Control
-} audio_control_cur_2_t;
-
-// 5.2.3.3 4-byte Control CUR Parameter Block
-typedef struct TU_ATTR_PACKED
-{
-  int32_t bCur              ;   ///< The setting for the CUR attribute of the addressed Control
-} audio_control_cur_4_t;
-
-// Use the following ONLY for RECEIVED data - compiler does not know how many subranges are defined! Use the one below for predefined lengths - or if you know what you are doing do what you like
-// 5.2.3.1 1-byte Control RANGE Parameter Block
 typedef struct TU_ATTR_PACKED {
-  uint16_t wNumSubRanges;
-  struct TU_ATTR_PACKED {
-    int8_t bMin             ; /*The setting for the MIN attribute of the nth subrange of the addressed Control*/
-    int8_t bMax             ; /*The setting for the MAX attribute of the nth subrange of the addressed Control*/
-    uint8_t bRes            ; /*The setting for the RES attribute of the nth subrange of the addressed Control*/
-  } subrange[]              ;
-} audio_control_range_1_t;
+  int16_t bCur;///< The setting for the CUR attribute of the addressed Control
+} audio20_control_cur_2_t;
 
-// 5.2.3.2 2-byte Control RANGE Parameter Block
+// 5.2.3.3 4-byte Control CUR Parameter Block
 typedef struct TU_ATTR_PACKED {
-  uint16_t wNumSubRanges;
-  struct TU_ATTR_PACKED {
-    int16_t bMin            ; /*The setting for the MIN attribute of the nth subrange of the addressed Control*/
-    int16_t bMax            ; /*The setting for the MAX attribute of the nth subrange of the addressed Control*/
-    uint16_t bRes           ; /*The setting for the RES attribute of the nth subrange of the addressed Control*/
-  } subrange[]              ;
-} audio_control_range_2_t;
+  int32_t bCur;///< The setting for the CUR attribute of the addressed Control
+} audio20_control_cur_4_t;
 
-// 5.2.3.3 4-byte Control RANGE Parameter Block
-typedef struct TU_ATTR_PACKED {
-  uint16_t wNumSubRanges;
-  struct TU_ATTR_PACKED {
-    int32_t bMin            ; /*The setting for the MIN attribute of the nth subrange of the addressed Control*/
-    int32_t bMax            ; /*The setting for the MAX attribute of the nth subrange of the addressed Control*/
-    uint32_t bRes           ; /*The setting for the RES attribute of the nth subrange of the addressed Control*/
-  } subrange[]              ;
-} audio_control_range_4_t;
+// Use the following ONLY for RECEIVED data - compiler does not know how many subranges are defined! Use the #define macros below for predefined lengths.
 
 // 5.2.3.1 1-byte Control RANGE Parameter Block
-#define audio_control_range_1_n_t(numSubRanges) \
-    struct TU_ATTR_PACKED {                     \
-  uint16_t wNumSubRanges;                       \
-  struct TU_ATTR_PACKED {                       \
-      int8_t bMin               ; /*The setting for the MIN attribute of the nth subrange of the addressed Control*/\
-    int8_t bMax                 ; /*The setting for the MAX attribute of the nth subrange of the addressed Control*/\
-    uint8_t bRes                ; /*The setting for the RES attribute of the nth subrange of the addressed Control*/\
-    } subrange[numSubRanges]    ;               \
-}
+#define audio20_control_range_1_n_t(numSubRanges)                                                      \
+  struct TU_ATTR_PACKED {                                                                              \
+    uint16_t wNumSubRanges;                                                                            \
+    struct TU_ATTR_PACKED {                                                                            \
+      int8_t bMin;  /*The setting for the MIN attribute of the nth subrange of the addressed Control*/ \
+      int8_t bMax;  /*The setting for the MAX attribute of the nth subrange of the addressed Control*/ \
+      uint8_t bRes; /*The setting for the RES attribute of the nth subrange of the addressed Control*/ \
+    } subrange[numSubRanges];                                                                          \
+  }
 
 /// 5.2.3.2 2-byte Control RANGE Parameter Block
-#define audio_control_range_2_n_t(numSubRanges) \
-    struct TU_ATTR_PACKED {                     \
-  uint16_t wNumSubRanges;                       \
-  struct TU_ATTR_PACKED {                       \
-      int16_t bMin          ; /*The setting for the MIN attribute of the nth subrange of the addressed Control*/\
-    int16_t bMax            ; /*The setting for the MAX attribute of the nth subrange of the addressed Control*/\
-    uint16_t bRes           ; /*The setting for the RES attribute of the nth subrange of the addressed Control*/\
-    } subrange[numSubRanges];                   \
-}
+#define audio20_control_range_2_n_t(numSubRanges)                                                       \
+  struct TU_ATTR_PACKED {                                                                               \
+    uint16_t wNumSubRanges;                                                                             \
+    struct TU_ATTR_PACKED {                                                                             \
+      int16_t bMin;  /*The setting for the MIN attribute of the nth subrange of the addressed Control*/ \
+      int16_t bMax;  /*The setting for the MAX attribute of the nth subrange of the addressed Control*/ \
+      uint16_t bRes; /*The setting for the RES attribute of the nth subrange of the addressed Control*/ \
+    } subrange[numSubRanges];                                                                           \
+  }
 
 // 5.2.3.3 4-byte Control RANGE Parameter Block
-#define audio_control_range_4_n_t(numSubRanges) \
-    struct TU_ATTR_PACKED {                     \
-  uint16_t wNumSubRanges;                       \
-  struct TU_ATTR_PACKED {                       \
-      int32_t bMin          ; /*The setting for the MIN attribute of the nth subrange of the addressed Control*/\
-    int32_t bMax            ; /*The setting for the MAX attribute of the nth subrange of the addressed Control*/\
-    uint32_t bRes           ; /*The setting for the RES attribute of the nth subrange of the addressed Control*/\
-    } subrange[numSubRanges];                   \
-}
+#define audio20_control_range_4_n_t(numSubRanges)                                                       \
+  struct TU_ATTR_PACKED {                                                                               \
+    uint16_t wNumSubRanges;                                                                             \
+    struct TU_ATTR_PACKED {                                                                             \
+      int32_t bMin;  /*The setting for the MIN attribute of the nth subrange of the addressed Control*/ \
+      int32_t bMax;  /*The setting for the MAX attribute of the nth subrange of the addressed Control*/ \
+      uint32_t bRes; /*The setting for the RES attribute of the nth subrange of the addressed Control*/ \
+    } subrange[numSubRanges];                                                                           \
+  }
 
 // 6.1 Interrupt Data Message Format
-typedef struct TU_ATTR_PACKED
-{
+typedef struct TU_ATTR_PACKED {
   uint8_t bInfo;
   uint8_t bAttribute;
-  union
-  {
+  union {
     uint16_t wValue;
-    struct
-    {
+    struct {
       uint8_t wValue_cn_or_mcn;
       uint8_t wValue_cs;
     };
   };
-  union
-  {
+  union {
     uint16_t wIndex;
-    struct
-    {
+    struct {
       uint8_t wIndex_ep_or_int;
       uint8_t wIndex_entity_id;
     };
   };
+} audio20_interrupt_data_t;
+
+//--------------------------------------------------------------------+
+// APPLICATION HELPER DEFINITIONS
+//--------------------------------------------------------------------+
+
+// Combined Interrupt Data Message Format for both UAC1 and UAC2
+typedef union {
+  audio10_interrupt_data_t v1;
+  audio20_interrupt_data_t v2;
 } audio_interrupt_data_t;
 
+// MIDI1.0 use the same CS AC Interface Descriptor as UAC1
+typedef audio10_desc_cs_ac_interface_n_t(1) midi10_desc_cs_ac_interface_t;
+
+// UAC1.0 AC Interface Descriptor with 1 interface, used to read fields other than baInterfaceNr
+typedef audio10_desc_cs_ac_interface_n_t(1) audio10_desc_cs_ac_interface_1_t;
+
 /** @} */
 
 #ifdef __cplusplus
diff --git a/src/class/audio/audio_device.c b/src/class/audio/audio_device.c
index 701411401..1dda8af99 100644
--- a/src/class/audio/audio_device.c
+++ b/src/class/audio/audio_device.c
@@ -79,10 +79,9 @@
 // Linear buffer in case target MCU is not capable of handling a ring buffer FIFO e.g. no hardware buffer
 // is available or driver is would need to be changed dramatically
 
-// Only STM32 and dcd_transdimension use non-linear buffer for now
-// dwc2 except esp32sx (since it may use dcd_esp32sx)
+// Only STM32 and ChipIdea HS use non-linear buffer for now
 // Ring buffer is incompatible with dcache, since neither address nor size is aligned to cache line
-#if (defined(TUP_USBIP_DWC2) && !TU_CHECK_MCU(OPT_MCU_ESP32S2, OPT_MCU_ESP32S3)) || \
+#if defined(TUP_USBIP_DWC2) || \
     defined(TUP_USBIP_FSDEV) ||                                                     \
     CFG_TUSB_MCU == OPT_MCU_RX63X ||                                                \
     CFG_TUSB_MCU == OPT_MCU_RX65X ||                                                \
@@ -181,16 +180,8 @@ tu_static CFG_TUD_MEM_SECTION struct {
 } lin_buf_out;
 #endif// CFG_TUD_AUDIO_ENABLE_EP_OUT && USE_LINEAR_BUFFER
 
-// Control buffers
-tu_static CFG_TUD_MEM_SECTION struct {
-  TUD_EPBUF_DEF(buf1, CFG_TUD_AUDIO_FUNC_1_CTRL_BUF_SZ);
-  #if CFG_TUD_AUDIO > 1
-  TUD_EPBUF_DEF(buf2, CFG_TUD_AUDIO_FUNC_2_CTRL_BUF_SZ);
-  #endif
-  #if CFG_TUD_AUDIO > 2
-  TUD_EPBUF_DEF(buf3, CFG_TUD_AUDIO_FUNC_3_CTRL_BUF_SZ);
-  #endif
-} ctrl_buf;
+// Control buffer
+CFG_TUD_MEM_ALIGN uint8_t ctrl_buf[CFG_TUD_AUDIO_CTRL_BUF_SZ];
 
 // Aligned buffer for feedback EP
 #if CFG_TUD_AUDIO_ENABLE_EP_OUT && CFG_TUD_AUDIO_ENABLE_FEEDBACK_EP
@@ -218,12 +209,15 @@ typedef struct
 {
   uint8_t rhport;
   uint8_t const *p_desc;// Pointer pointing to Standard AC Interface Descriptor(4.7.1) - Audio Control descriptor defining audio function
+  uint8_t const *p_desc_as;// Pointer pointing to 1st Standard AS Interface Descriptor(4.9.1) - Audio Streaming descriptor defining audio function
+  uint16_t desc_length;// Length of audio function descriptor
 
 #if CFG_TUD_AUDIO_ENABLE_EP_IN
   uint8_t ep_in;            // TX audio data EP.
   uint16_t ep_in_sz;        // Current size of TX EP
   uint8_t ep_in_as_intf_num;// Corresponding Standard AS Interface Descriptor (4.9.1) belonging to output terminal to which this EP belongs - 0 is invalid (this fits to UAC2 specification since AS interfaces can not have interface number equal to zero)
   uint8_t ep_in_alt;        // Current alternate setting of TX EP
+  uint16_t ep_in_fifo_threshold;// Target size for the EP IN FIFO.
   #endif
 
 #if CFG_TUD_AUDIO_ENABLE_EP_OUT
@@ -243,8 +237,6 @@ typedef struct
 
   bool mounted;// Device opened
 
-  uint16_t desc_length;// Length of audio function descriptor
-
 #if CFG_TUD_AUDIO_ENABLE_FEEDBACK_EP
   struct {
     uint32_t value;    // Feedback value for asynchronous mode (in 16.16 format).
@@ -253,7 +245,6 @@ typedef struct
 
     uint8_t frame_shift;// bInterval-1 in unit of frame (FS), micro-frame (HS)
     uint8_t compute_method;
-    bool format_correction;
     union {
       uint8_t power_of_2;// pre-computed power of 2 shift
       float float_const; // pre-computed float constant
@@ -279,21 +270,13 @@ typedef struct
   uint16_t packet_sz_tx[3];
   uint8_t bclock_id_tx;
   uint8_t interval_tx;
-#endif
-
-// Encoding parameters - parameters are set when alternate AS interface is set by host
-#if CFG_TUD_AUDIO_ENABLE_EP_IN && CFG_TUD_AUDIO_EP_IN_FLOW_CONTROL
-  audio_format_type_t format_type_tx;
+  uint8_t format_type_tx;
   uint8_t n_channels_tx;
   uint8_t n_bytes_per_sample_tx;
 #endif
 
   /*------------- From this point, data is not cleared by bus reset -------------*/
 
-  // Buffer for control requests
-  uint8_t *ctrl_buf;
-  uint8_t ctrl_buf_sz;
-
 // EP Transfer buffers and FIFOs
 #if CFG_TUD_AUDIO_ENABLE_EP_OUT
   tu_fifo_t ep_out_ff;
@@ -327,7 +310,11 @@ typedef struct
   #define USE_LINEAR_BUFFER_RX 0
 #endif
 
-#define ITF_MEM_RESET_SIZE offsetof(audiod_function_t, ctrl_buf)
+#if CFG_TUD_AUDIO_ENABLE_EP_OUT
+#define ITF_MEM_RESET_SIZE offsetof(audiod_function_t, ep_out_ff)
+#else
+#define ITF_MEM_RESET_SIZE offsetof(audiod_function_t, ep_in_ff)
+#endif
 
 //--------------------------------------------------------------------+
 // WEAK FUNCTION STUBS
@@ -363,11 +350,6 @@ TU_ATTR_WEAK void tud_audio_feedback_params_cb(uint8_t func_id, uint8_t alt_itf,
   feedback_param->method = AUDIO_FEEDBACK_METHOD_DISABLED;
 }
 
-TU_ATTR_WEAK bool tud_audio_feedback_format_correction_cb(uint8_t func_id) {
-  (void) func_id;
-  return CFG_TUD_AUDIO_ENABLE_FEEDBACK_FORMAT_CORRECTION;
-}
-
 TU_ATTR_WEAK TU_ATTR_FAST_FUNC void tud_audio_feedback_interval_isr(uint8_t func_id, uint32_t frame_number, uint8_t interval_shift) {
   (void) func_id;
   (void) frame_number;
@@ -376,7 +358,7 @@ TU_ATTR_WEAK TU_ATTR_FAST_FUNC void tud_audio_feedback_interval_isr(uint8_t func
 #endif
 
 #if CFG_TUD_AUDIO_ENABLE_INTERRUPT_EP
-TU_ATTR_WEAK void tud_audio_int_xfer_cb(uint8_t rhport) {
+TU_ATTR_WEAK void tud_audio_int_done_cb(uint8_t rhport) {
   (void) rhport;
 }
 #endif
@@ -465,16 +447,16 @@ static bool audiod_set_interface(uint8_t rhport, tusb_control_request_t const *p
 static bool audiod_verify_entity_exists(uint8_t itf, uint8_t entityID, uint8_t *func_id);
 static bool audiod_verify_itf_exists(uint8_t itf, uint8_t *func_id);
 static bool audiod_verify_ep_exists(uint8_t ep, uint8_t *func_id);
-static uint8_t audiod_get_audio_fct_idx(audiod_function_t *audio);
+static inline uint8_t audiod_get_audio_fct_idx(audiod_function_t *audio);
 
 #if CFG_TUD_AUDIO_ENABLE_EP_IN && CFG_TUD_AUDIO_EP_IN_FLOW_CONTROL
 static void audiod_parse_flow_control_params(audiod_function_t *audio, uint8_t const *p_desc);
 static bool audiod_calc_tx_packet_sz(audiod_function_t *audio);
-static uint16_t audiod_tx_packet_size(const uint16_t *norminal_size, uint16_t data_count, uint16_t fifo_depth, uint16_t max_size);
+static uint16_t audiod_tx_packet_size(const uint16_t *nominal_size, uint16_t data_count, uint16_t fifo_depth, uint16_t fifo_threshold, uint16_t max_size);
 #endif
 
 #if CFG_TUD_AUDIO_ENABLE_EP_OUT && CFG_TUD_AUDIO_ENABLE_FEEDBACK_EP
-static bool audiod_set_fb_params_freq(audiod_function_t *audio, uint32_t sample_freq, uint32_t mclk_freq);
+static bool audiod_fb_params_prepare(uint8_t func_id, uint8_t alt);
 static void audiod_fb_fifo_count_update(audiod_function_t *audio, uint16_t lvl_new);
 #endif
 
@@ -518,13 +500,13 @@ static bool audiod_rx_xfer_isr(uint8_t rhport, audiod_function_t* audio, uint16_
 
   #if USE_LINEAR_BUFFER_RX
   // Data currently is in linear buffer, copy into EP OUT FIFO
-  TU_VERIFY(tu_fifo_write_n(&audio->ep_out_ff, audio->lin_buf_out, n_bytes_received));
+  TU_VERIFY(0 < tu_fifo_write_n(&audio->ep_out_ff, audio->lin_buf_out, n_bytes_received));
 
   // Schedule for next receive
-  TU_VERIFY(usbd_edpt_xfer(rhport, audio->ep_out, audio->lin_buf_out, audio->ep_out_sz), false);
+  TU_VERIFY(usbd_edpt_xfer(rhport, audio->ep_out, audio->lin_buf_out, audio->ep_out_sz, true));
   #else
   // Data is already placed in EP FIFO, schedule for next receive
-  TU_VERIFY(usbd_edpt_xfer_fifo(rhport, audio->ep_out, &audio->ep_out_ff, audio->ep_out_sz), false);
+  TU_VERIFY(usbd_edpt_xfer_fifo(rhport, audio->ep_out, &audio->ep_out_ff, audio->ep_out_sz, true));
   #endif
 
   #if CFG_TUD_AUDIO_ENABLE_FEEDBACK_EP
@@ -564,6 +546,17 @@ tu_fifo_t *tud_audio_n_get_ep_in_ff(uint8_t func_id) {
   return NULL;
 }
 
+uint16_t tud_audio_n_get_ep_in_fifo_threshold(uint8_t func_id) {
+  if (func_id < CFG_TUD_AUDIO) return _audiod_fct[func_id].ep_in_fifo_threshold;
+  return 0;
+}
+
+void tud_audio_n_set_ep_in_fifo_threshold(uint8_t func_id, uint16_t threshold) {
+  if (func_id < CFG_TUD_AUDIO && threshold < _audiod_fct[func_id].ep_in_ff.depth) {
+    _audiod_fct[func_id].ep_in_fifo_threshold = threshold;
+  }
+}
+
 static bool audiod_tx_xfer_isr(uint8_t rhport, audiod_function_t * audio, uint16_t n_bytes_sent) {
   uint8_t idx_audio_fct = audiod_get_audio_fct_idx(audio);
 
@@ -575,16 +568,16 @@ static bool audiod_tx_xfer_isr(uint8_t rhport, audiod_function_t * audio, uint16
 
   #if CFG_TUD_AUDIO_EP_IN_FLOW_CONTROL
   // packet_sz_tx is based on total packet size, here we want size for each support buffer.
-  n_bytes_tx = audiod_tx_packet_size(audio->packet_sz_tx, tu_fifo_count(&audio->ep_in_ff), audio->ep_in_ff.depth, audio->ep_in_sz);
+  n_bytes_tx = audiod_tx_packet_size(audio->packet_sz_tx, tu_fifo_count(&audio->ep_in_ff), audio->ep_in_ff.depth, audio->ep_in_fifo_threshold, audio->ep_in_sz);
   #else
   n_bytes_tx = tu_min16(tu_fifo_count(&audio->ep_in_ff), audio->ep_in_sz);// Limit up to max packet size, more can not be done for ISO
   #endif
   #if USE_LINEAR_BUFFER_TX
   tu_fifo_read_n(&audio->ep_in_ff, audio->lin_buf_in, n_bytes_tx);
-  TU_VERIFY(usbd_edpt_xfer(rhport, audio->ep_in, audio->lin_buf_in, n_bytes_tx));
+  TU_VERIFY(usbd_edpt_xfer(rhport, audio->ep_in, audio->lin_buf_in, n_bytes_tx, true));
   #else
   // Send everything in ISO EP FIFO
-  TU_VERIFY(usbd_edpt_xfer_fifo(rhport, audio->ep_in, &audio->ep_in_ff, n_bytes_tx));
+  TU_VERIFY(usbd_edpt_xfer_fifo(rhport, audio->ep_in, &audio->ep_in_ff, n_bytes_tx, true));
   #endif
 
   // Call a weak callback here - a possibility for user to get informed former TX was completed and data gets now loaded into EP in buffer
@@ -595,6 +588,10 @@ static bool audiod_tx_xfer_isr(uint8_t rhport, audiod_function_t * audio, uint16
 
 #endif
 
+//--------------------------------------------------------------------+
+// OTHER API
+//--------------------------------------------------------------------+
+
 #if CFG_TUD_AUDIO_ENABLE_INTERRUPT_EP
 // If no interrupt transmit is pending bytes get written into buffer and a transmit is scheduled - once transmit completed tud_audio_int_done_cb() is called in inform user
 bool tud_audio_int_n_write(uint8_t func_id, const audio_interrupt_data_t *data) {
@@ -605,10 +602,15 @@ bool tud_audio_int_n_write(uint8_t func_id, const audio_interrupt_data_t *data)
   // We write directly into the EP's buffer - abort if previous transfer not complete
   TU_VERIFY(usbd_edpt_claim(_audiod_fct[func_id].rhport, _audiod_fct[func_id].ep_int));
 
+  uint8_t size = tud_audio_n_version(func_id) == 2 ? sizeof(audio20_interrupt_data_t) : sizeof(audio10_interrupt_data_t);
+
+  // INT EP buffer must be large enough
+  TU_ASSERT(size <= sizeof(int_ep_buf[func_id].buf));
+
   // Check length
-  if (tu_memcpy_s(int_ep_buf[func_id].buf, sizeof(int_ep_buf[func_id].buf), data, sizeof(audio_interrupt_data_t)) == 0) {
+  if (tu_memcpy_s(int_ep_buf[func_id].buf, sizeof(int_ep_buf[func_id].buf), data, size) == 0) {
     // Schedule transmit
-    TU_ASSERT(usbd_edpt_xfer(_audiod_fct[func_id].rhport, _audiod_fct[func_id].ep_int, int_ep_buf[func_id].buf, sizeof(int_ep_buf[func_id].buf)), 0);
+    TU_ASSERT(usbd_edpt_xfer(_audiod_fct[func_id].rhport, _audiod_fct[func_id].ep_int, int_ep_buf[func_id].buf, size, false));
   } else {
     // Release endpoint since we don't make any transfer
     usbd_edpt_release(_audiod_fct[func_id].rhport, _audiod_fct[func_id].ep_int);
@@ -620,10 +622,11 @@ bool tud_audio_int_n_write(uint8_t func_id, const audio_interrupt_data_t *data)
 
 #if CFG_TUD_AUDIO_ENABLE_EP_OUT && CFG_TUD_AUDIO_ENABLE_FEEDBACK_EP
 // This function is called once a transmit of a feedback packet was successfully completed. Here, we get the next feedback value to be sent
-static inline bool audiod_fb_send(audiod_function_t *audio) {
-  bool apply_correction = (TUSB_SPEED_FULL == tud_speed_get()) && audio->feedback.format_correction;
+static inline bool audiod_fb_send(uint8_t func_id, bool is_isr) {
+  audiod_function_t *audio = &_audiod_fct[func_id];
+  uint8_t uac_version = tud_audio_n_version(func_id);
   // Format the feedback value
-  if (apply_correction) {
+  if (uac_version == 1) {
     uint8_t *fb = (uint8_t *) audio->fb_buf;
 
     // For FS format is 10.14
@@ -635,23 +638,70 @@ static inline bool audiod_fb_send(audiod_function_t *audio) {
     *audio->fb_buf = audio->feedback.value;
   }
 
-  // About feedback format on FS
-  //
-  // 3 variables: Format | packetSize | sendSize | Working OS:
-  //              16.16    4            4          Linux, Windows
-  //              16.16    4            3          Linux
-  //              16.16    3            4          Linux
-  //              16.16    3            3          Linux
-  //              10.14    4            4          Linux
-  //              10.14    4            3          Linux
-  //              10.14    3            4          Linux, OSX
-  //              10.14    3            3          Linux, OSX
-  //
-  // We send 3 bytes since sending packet larger than wMaxPacketSize is pretty ugly
-  return usbd_edpt_xfer(audio->rhport, audio->ep_fb, (uint8_t *) audio->fb_buf, apply_correction ? 3 : 4);
+  return usbd_edpt_xfer(audio->rhport, audio->ep_fb, (uint8_t *) audio->fb_buf, uac_version == 1 ? 3 : 4, is_isr);
+}
+
+uint32_t tud_audio_feedback_update(uint8_t func_id, uint32_t cycles) {
+  audiod_function_t *audio = &_audiod_fct[func_id];
+  uint32_t feedback;
+
+  switch (audio->feedback.compute_method) {
+    case AUDIO_FEEDBACK_METHOD_FREQUENCY_POWER_OF_2:
+      feedback = (cycles << audio->feedback.compute.power_of_2);
+      break;
+
+    case AUDIO_FEEDBACK_METHOD_FREQUENCY_FLOAT:
+      feedback = (uint32_t) ((float) cycles * audio->feedback.compute.float_const);
+      break;
+
+    case AUDIO_FEEDBACK_METHOD_FREQUENCY_FIXED: {
+      uint64_t fb64 = (((uint64_t) cycles) * audio->feedback.compute.fixed.sample_freq) << (16 - (audio->feedback.frame_shift - 1));
+      feedback = (uint32_t) (fb64 / audio->feedback.compute.fixed.mclk_freq);
+    } break;
+
+    default:
+      return 0;
+  }
+
+  // For Windows: https://docs.microsoft.com/en-us/windows-hardware/drivers/audio/usb-2-0-audio-drivers
+  // The size of isochronous packets created by the device must be within the limits specified in FMT-2.0 section 2.3.1.1.
+  // This means that the deviation of actual packet size from nominal size must not exceed +/- one audio slot
+  // (audio slot = channel count samples).
+  if (feedback > audio->feedback.max_value) {
+    feedback = audio->feedback.max_value;
+  }
+  if (feedback < audio->feedback.min_value) {
+    feedback = audio->feedback.min_value;
+  }
+
+  tud_audio_n_fb_set(func_id, feedback);
+
+  return feedback;
+}
+
+bool tud_audio_n_fb_set(uint8_t func_id, uint32_t feedback) {
+  TU_VERIFY(func_id < CFG_TUD_AUDIO && _audiod_fct[func_id].p_desc != NULL);
+
+  _audiod_fct[func_id].feedback.value = feedback;
+
+  return true;
 }
 #endif
 
+uint8_t tud_audio_n_version(uint8_t func_id) {
+  TU_VERIFY(func_id < CFG_TUD_AUDIO && _audiod_fct[func_id].p_desc != NULL);
+
+  uint8_t bIntfProtocol = ((tusb_desc_interface_t const *)_audiod_fct[func_id].p_desc)->bInterfaceProtocol;
+
+  if (bIntfProtocol == AUDIO_INT_PROTOCOL_CODE_V1) {
+    return 1;
+  } else if (bIntfProtocol == AUDIO_INT_PROTOCOL_CODE_V2) {
+    return 2;
+  } else {
+    return 0; // Unknown version
+  }
+}
+
 //--------------------------------------------------------------------+
 // USBD Driver API
 //--------------------------------------------------------------------+
@@ -661,29 +711,8 @@ void audiod_init(void) {
   for (uint8_t i = 0; i < CFG_TUD_AUDIO; i++) {
     audiod_function_t *audio = &_audiod_fct[i];
 
-    // Initialize control buffers
-    switch (i) {
-      case 0:
-        audio->ctrl_buf = ctrl_buf.buf1;
-        audio->ctrl_buf_sz = CFG_TUD_AUDIO_FUNC_1_CTRL_BUF_SZ;
-        break;
-#if CFG_TUD_AUDIO > 1 && CFG_TUD_AUDIO_FUNC_2_CTRL_BUF_SZ > 0
-      case 1:
-        audio->ctrl_buf = ctrl_buf.buf2;
-        audio->ctrl_buf_sz = CFG_TUD_AUDIO_FUNC_2_CTRL_BUF_SZ;
-        break;
-#endif
-#if CFG_TUD_AUDIO > 2 && CFG_TUD_AUDIO_FUNC_3_CTRL_BUF_SZ > 0
-      case 2:
-        audio->ctrl_buf = ctrl_buf.buf3;
-        audio->ctrl_buf_sz = CFG_TUD_AUDIO_FUNC_3_CTRL_BUF_SZ;
-        break;
-#endif
-    }
-
       // Initialize IN EP FIFO if required
 #if CFG_TUD_AUDIO_ENABLE_EP_IN
-
     switch (i) {
   #if CFG_TUD_AUDIO_FUNC_1_EP_IN_SW_BUF_SZ > 0
       case 0:
@@ -817,7 +846,8 @@ uint16_t audiod_open(uint8_t rhport, tusb_desc_interface_t const *itf_desc, uint
             AUDIO_SUBCLASS_CONTROL == itf_desc->bInterfaceSubClass);
 
   // Verify version is correct - this check can be omitted
-  TU_VERIFY(itf_desc->bInterfaceProtocol == AUDIO_INT_PROTOCOL_CODE_V2);
+  TU_VERIFY(itf_desc->bInterfaceProtocol == AUDIO_INT_PROTOCOL_CODE_V1 ||
+            itf_desc->bInterfaceProtocol == AUDIO_INT_PROTOCOL_CODE_V2);
 
   // Verify interrupt control EP is enabled if demanded by descriptor
   TU_ASSERT(itf_desc->bNumEndpoints <= 1);// 0 or 1 EPs are allowed
@@ -835,21 +865,32 @@ uint16_t audiod_open(uint8_t rhport, tusb_desc_interface_t const *itf_desc, uint
       _audiod_fct[i].p_desc = (uint8_t const *) itf_desc;// Save pointer to AC descriptor which is by specification always the first one
       _audiod_fct[i].rhport = rhport;
 
-      // Setup descriptor lengths
-      switch (i) {
-        case 0:
-          _audiod_fct[i].desc_length = CFG_TUD_AUDIO_FUNC_1_DESC_LEN;
-          break;
-#if CFG_TUD_AUDIO > 1
-        case 1:
-          _audiod_fct[i].desc_length = CFG_TUD_AUDIO_FUNC_2_DESC_LEN;
-          break;
-#endif
-#if CFG_TUD_AUDIO > 2
-        case 2:
-          _audiod_fct[i].desc_length = CFG_TUD_AUDIO_FUNC_3_DESC_LEN;
-          break;
-#endif
+      // Calculate descriptor length
+      {
+        uint8_t const *p_desc = (uint8_t const *) itf_desc;
+        uint8_t const *p_desc_end = p_desc + max_len;
+        uint16_t total_len = sizeof(tusb_desc_interface_t);
+        // Skip Standard AC interface descriptor
+        p_desc = tu_desc_next(p_desc);
+        while (p_desc_end - p_desc > 0) {
+          // Stop if:
+          // - Non audio streaming interface descriptor found
+          // - IAD found
+          if ((tu_desc_type(p_desc) == TUSB_DESC_INTERFACE &&
+              !(((tusb_desc_interface_t const *) p_desc)->bInterfaceClass == TUSB_CLASS_AUDIO && ((tusb_desc_interface_t const *) p_desc)->bInterfaceSubClass == AUDIO_SUBCLASS_STREAMING))
+              || tu_desc_type(p_desc) == TUSB_DESC_INTERFACE_ASSOCIATION) {
+            break;
+          } else if (tu_desc_type(p_desc) == TUSB_DESC_INTERFACE && ((tusb_desc_interface_t const *) p_desc)->bInterfaceSubClass == AUDIO_SUBCLASS_STREAMING) {
+            if (_audiod_fct[i].p_desc_as == NULL) {
+              _audiod_fct[i].p_desc_as = p_desc;
+            }
+          } else {
+            // nothing to do
+          }
+          total_len += p_desc[0];
+          p_desc = tu_desc_next(p_desc);
+        }
+        _audiod_fct[i].desc_length = total_len;
       }
 
 #ifdef TUP_DCD_EDPT_ISO_ALLOC
@@ -868,54 +909,67 @@ uint16_t audiod_open(uint8_t rhport, tusb_desc_interface_t const *itf_desc, uint
         uint8_t ep_fb = 0;
   #endif
         uint8_t const *p_desc = _audiod_fct[i].p_desc;
-        uint8_t const *p_desc_end = p_desc + _audiod_fct[i].desc_length - TUD_AUDIO_DESC_IAD_LEN;
+        uint8_t const *p_desc_end = p_desc + _audiod_fct[i].desc_length;
         // Condition modified from p_desc < p_desc_end to prevent gcc>=12 strict-overflow warning
         while (p_desc_end - p_desc > 0) {
           if (tu_desc_type(p_desc) == TUSB_DESC_ENDPOINT) {
+            // Unified UAC1/UAC2 endpoint processing
             tusb_desc_endpoint_t const *desc_ep = (tusb_desc_endpoint_t const *) p_desc;
-            if (desc_ep->bmAttributes.xfer == TUSB_XFER_ISOCHRONOUS) {
-  #if CFG_TUD_AUDIO_ENABLE_FEEDBACK_EP
-              // Explicit feedback EP
-              if (desc_ep->bmAttributes.usage == 1) {
-                ep_fb = desc_ep->bEndpointAddress;
-              }
-  #endif
-  #if CFG_TUD_AUDIO_ENABLE_EP_IN
-              // Data or data with implicit feedback IN EP
-              if (tu_edpt_dir(desc_ep->bEndpointAddress) == TUSB_DIR_IN
-                  && (desc_ep->bmAttributes.usage == 0 || desc_ep->bmAttributes.usage == 2)) {
-                ep_in = desc_ep->bEndpointAddress;
-                ep_in_size = TU_MAX(tu_edpt_packet_size(desc_ep), ep_in_size);
-              }
-  #endif
-  #if CFG_TUD_AUDIO_ENABLE_EP_OUT
-              // Data OUT EP
-              if (tu_edpt_dir(desc_ep->bEndpointAddress) == TUSB_DIR_OUT
-                  && desc_ep->bmAttributes.usage == 0) {
-                ep_out = desc_ep->bEndpointAddress;
-                ep_out_size = TU_MAX(tu_edpt_packet_size(desc_ep), ep_out_size);
-              }
-  #endif
+            bool is_feedback_ep = false;
+            bool is_data_ep = false;
+
+            if (tud_audio_n_version(i) == 1) {
+              // UAC1: Use bRefresh field to distinguish endpoint types
+              audio10_desc_as_iso_data_ep_t const *desc_ep_uac1 = (audio10_desc_as_iso_data_ep_t const *) p_desc;
+              is_data_ep = (desc_ep_uac1->bmAttributes.sync != TUSB_ISO_EP_ATT_NO_SYNC);
+              is_feedback_ep = (desc_ep_uac1->bmAttributes.sync == TUSB_ISO_EP_ATT_NO_SYNC);
+            } else {
+              // UAC2: Use bmAttributes.usage to distinguish endpoint types
+              is_data_ep = (desc_ep->bmAttributes.usage == 0 || desc_ep->bmAttributes.usage == 2);
+              is_feedback_ep = (desc_ep->bmAttributes.usage == 1);
             }
+
+    #if CFG_TUD_AUDIO_ENABLE_FEEDBACK_EP
+            // Explicit feedback EP
+            if (is_feedback_ep) {
+              ep_fb = desc_ep->bEndpointAddress;
+            }
+    #else
+            (void) is_feedback_ep;
+    #endif
+    #if CFG_TUD_AUDIO_ENABLE_EP_IN
+            // Data or data with implicit feedback IN EP
+            if (tu_edpt_dir(desc_ep->bEndpointAddress) == TUSB_DIR_IN && is_data_ep) {
+              ep_in = desc_ep->bEndpointAddress;
+              ep_in_size = TU_MAX(tu_edpt_packet_size(desc_ep), ep_in_size);
+            }
+    #endif
+    #if CFG_TUD_AUDIO_ENABLE_EP_OUT
+            // Data OUT EP
+            if (tu_edpt_dir(desc_ep->bEndpointAddress) == TUSB_DIR_OUT && is_data_ep) {
+              ep_out = desc_ep->bEndpointAddress;
+              ep_out_size = TU_MAX(tu_edpt_packet_size(desc_ep), ep_out_size);
+            }
+    #endif
           }
 
           p_desc = tu_desc_next(p_desc);
         }
 
   #if CFG_TUD_AUDIO_ENABLE_EP_IN
-        if (ep_in) {
+        if (ep_in != 0) {
           usbd_edpt_iso_alloc(rhport, ep_in, ep_in_size);
         }
   #endif
 
   #if CFG_TUD_AUDIO_ENABLE_EP_OUT
-        if (ep_out) {
+        if (ep_out != 0) {
           usbd_edpt_iso_alloc(rhport, ep_out, ep_out_size);
         }
   #endif
 
   #if CFG_TUD_AUDIO_ENABLE_FEEDBACK_EP
-        if (ep_fb) {
+        if (ep_fb != 0) {
           usbd_edpt_iso_alloc(rhport, ep_fb, 4);
         }
   #endif
@@ -925,22 +979,27 @@ uint16_t audiod_open(uint8_t rhport, tusb_desc_interface_t const *itf_desc, uint
 #if CFG_TUD_AUDIO_ENABLE_EP_IN && CFG_TUD_AUDIO_EP_IN_FLOW_CONTROL
       {
         uint8_t const *p_desc = _audiod_fct[i].p_desc;
-        uint8_t const *p_desc_end = p_desc + _audiod_fct[i].desc_length - TUD_AUDIO_DESC_IAD_LEN;
+        uint8_t const *p_desc_end = p_desc + _audiod_fct[i].desc_length;
         // Condition modified from p_desc < p_desc_end to prevent gcc>=12 strict-overflow warning
         while (p_desc_end - p_desc > 0) {
           if (tu_desc_type(p_desc) == TUSB_DESC_ENDPOINT) {
             tusb_desc_endpoint_t const *desc_ep = (tusb_desc_endpoint_t const *) p_desc;
             if (desc_ep->bmAttributes.xfer == TUSB_XFER_ISOCHRONOUS) {
               // For data or data with implicit feedback IN EP
+              // For UAC1 this is always the case since there is no usage field
               if (tu_edpt_dir(desc_ep->bEndpointAddress) == TUSB_DIR_IN
                   && (desc_ep->bmAttributes.usage == 0 || desc_ep->bmAttributes.usage == 2)) {
                 _audiod_fct[i].interval_tx = desc_ep->bInterval;
               }
             }
-          } else if (tu_desc_type(p_desc) == TUSB_DESC_CS_INTERFACE && tu_desc_subtype(p_desc) == AUDIO_CS_AC_INTERFACE_OUTPUT_TERMINAL) {
+          } else if (tud_audio_n_version(i) == 2 &&
+              tu_desc_type(p_desc) == TUSB_DESC_CS_INTERFACE && tu_desc_subtype(p_desc) == AUDIO20_CS_AC_INTERFACE_OUTPUT_TERMINAL) {
+              // For UAC2 only, UAC1 doesn't have a clock source
             if (tu_unaligned_read16(p_desc + 4) == AUDIO_TERM_TYPE_USB_STREAMING) {
               _audiod_fct[i].bclock_id_tx = p_desc[8];
             }
+          } else {
+            // nothing to do
           }
           p_desc = tu_desc_next(p_desc);
         }
@@ -950,7 +1009,7 @@ uint16_t audiod_open(uint8_t rhport, tusb_desc_interface_t const *itf_desc, uint
 #if CFG_TUD_AUDIO_ENABLE_INTERRUPT_EP
       {
         uint8_t const *p_desc = _audiod_fct[i].p_desc;
-        uint8_t const *p_desc_end = p_desc + _audiod_fct[i].desc_length - TUD_AUDIO_DESC_IAD_LEN;
+        uint8_t const *p_desc_end = p_desc + _audiod_fct[i].desc_length;
         // Condition modified from p_desc < p_desc_end to prevent gcc>=12 strict-overflow warning
         while (p_desc_end - p_desc > 0) {
           // For each endpoint
@@ -978,7 +1037,7 @@ uint16_t audiod_open(uint8_t rhport, tusb_desc_interface_t const *itf_desc, uint
   TU_ASSERT(i < CFG_TUD_AUDIO);
 
   // This is all we need so far - the EPs are setup by a later set_interface request (as per UAC2 specification)
-  uint16_t drv_len = _audiod_fct[i].desc_length - TUD_AUDIO_DESC_IAD_LEN;// - TUD_AUDIO_DESC_IAD_LEN since tinyUSB already handles the IAD descriptor
+  uint16_t drv_len = _audiod_fct[i].desc_length;
 
   return drv_len;
 }
@@ -1088,11 +1147,10 @@ static bool audiod_set_interface(uint8_t rhport, tusb_control_request_t const *p
 #endif// CFG_TUD_AUDIO_ENABLE_EP_OUT
 
   // Open new EP if necessary - EPs are only to be closed or opened for AS interfaces - Look for AS interface with correct alternate interface
-  uint8_t const *p_desc = tu_desc_next(audio->p_desc);
-  // Skip entire AC descriptor block
-  p_desc += ((audio_desc_cs_ac_interface_t const *) p_desc)->wTotalLength;
+
+  uint8_t const *p_desc = audio->p_desc_as;
   // Get pointer at end
-  uint8_t const *p_desc_end = audio->p_desc + audio->desc_length - TUD_AUDIO_DESC_IAD_LEN;
+  uint8_t const *p_desc_end = audio->p_desc + audio->desc_length;
 
   // p_desc starts at required interface with alternate setting zero
   // Condition modified from p_desc < p_desc_end to prevent gcc>=12 strict-overflow warning
@@ -1115,18 +1173,34 @@ static bool audiod_set_interface(uint8_t rhport, tusb_control_request_t const *p
 #endif
           uint8_t const ep_addr = desc_ep->bEndpointAddress;
 
+          bool is_feedback_ep = false;
+          bool is_data_ep = false;
+
+          if (tud_audio_n_version(func_id) == 1) {
+            // UAC1: Use bRefresh field to distinguish endpoint types
+            audio10_desc_as_iso_data_ep_t const *desc_ep_uac1 = (audio10_desc_as_iso_data_ep_t const *) p_desc;
+            is_data_ep = (desc_ep_uac1->bmAttributes.sync != TUSB_ISO_EP_ATT_NO_SYNC);
+            is_feedback_ep = (desc_ep_uac1->bmAttributes.sync == TUSB_ISO_EP_ATT_NO_SYNC);
+          } else {
+            // UAC2: Use bmAttributes.usage to distinguish endpoint types
+            is_data_ep = (desc_ep->bmAttributes.usage == 0 || desc_ep->bmAttributes.usage == 2);
+            is_feedback_ep = (desc_ep->bmAttributes.usage == 1);
+          }
+
           //TODO: We need to set EP non busy since this is not taken care of right now in ep_close() - THIS IS A WORKAROUND!
           usbd_edpt_clear_stall(rhport, ep_addr);
 
 #if CFG_TUD_AUDIO_ENABLE_EP_IN
           // For data or data with implicit feedback IN EP
-          if (tu_edpt_dir(ep_addr) == TUSB_DIR_IN && (desc_ep->bmAttributes.usage == 0 || desc_ep->bmAttributes.usage == 2))
+          if (tu_edpt_dir(ep_addr) == TUSB_DIR_IN && is_data_ep)
           {
             // Save address
             audio->ep_in = ep_addr;
             audio->ep_in_as_intf_num = itf;
             audio->ep_in_alt = alt;
             audio->ep_in_sz = tu_edpt_packet_size(desc_ep);
+            // Set the default EP IN FIFO threshold to half fifo depth.
+            audio->ep_in_fifo_threshold = audio->ep_in_ff.depth / 2;
 
             // If flow control is enabled, parse for the corresponding parameters - doing this here means only AS interfaces with EPs get scanned for parameters
   #if  CFG_TUD_AUDIO_EP_IN_FLOW_CONTROL
@@ -1134,17 +1208,17 @@ static bool audiod_set_interface(uint8_t rhport, tusb_control_request_t const *p
   #endif
             // Schedule first transmit if alternate interface is not zero, as sample data is available a ZLP is loaded
   #if USE_LINEAR_BUFFER_TX
-            TU_VERIFY(usbd_edpt_xfer(rhport, audio->ep_in, audio->lin_buf_in, 0));
+            TU_VERIFY(usbd_edpt_xfer(rhport, audio->ep_in, audio->lin_buf_in, 0, false));
   #else
             // Send everything in ISO EP FIFO
-            TU_VERIFY(usbd_edpt_xfer_fifo(rhport, audio->ep_in, &audio->ep_in_ff, 0));
+            TU_VERIFY(usbd_edpt_xfer_fifo(rhport, audio->ep_in, &audio->ep_in_ff, 0, false));
   #endif
           }
 #endif// CFG_TUD_AUDIO_ENABLE_EP_IN
 
 #if CFG_TUD_AUDIO_ENABLE_EP_OUT
           // Checking usage not necessary
-          if (tu_edpt_dir(ep_addr) == TUSB_DIR_OUT) {
+          if (tu_edpt_dir(ep_addr) == TUSB_DIR_OUT && is_data_ep) {
             // Save address
             audio->ep_out = ep_addr;
             audio->ep_out_as_intf_num = itf;
@@ -1153,21 +1227,25 @@ static bool audiod_set_interface(uint8_t rhport, tusb_control_request_t const *p
 
             // Prepare for incoming data
   #if USE_LINEAR_BUFFER_RX
-            TU_VERIFY(usbd_edpt_xfer(rhport, audio->ep_out, audio->lin_buf_out, audio->ep_out_sz), false);
+            TU_VERIFY(usbd_edpt_xfer(rhport, audio->ep_out, audio->lin_buf_out, audio->ep_out_sz, false));
   #else
-            TU_VERIFY(usbd_edpt_xfer_fifo(rhport, audio->ep_out, &audio->ep_out_ff, audio->ep_out_sz), false);
+            TU_VERIFY(usbd_edpt_xfer_fifo(rhport, audio->ep_out, &audio->ep_out_ff, audio->ep_out_sz, false));
   #endif
           }
 
   #if CFG_TUD_AUDIO_ENABLE_FEEDBACK_EP
           // Check if usage is explicit data feedback
-          if (tu_edpt_dir(ep_addr) == TUSB_DIR_IN && desc_ep->bmAttributes.usage == 1) {
+          if (is_feedback_ep) {
             audio->ep_fb = ep_addr;
             audio->feedback.frame_shift = desc_ep->bInterval - 1;
             // Schedule first feedback transmit
-            audiod_fb_send(audio);
+            audiod_fb_send(func_id, false);
           }
+  #else
+          (void) is_feedback_ep;
   #endif
+#else
+        (void) is_feedback_ep;
 #endif// CFG_TUD_AUDIO_ENABLE_EP_OUT
 
           foundEPs += 1;
@@ -1181,50 +1259,8 @@ static bool audiod_set_interface(uint8_t rhport, tusb_control_request_t const *p
       TU_VERIFY(tud_audio_set_itf_cb(rhport, p_request));
 
 #if CFG_TUD_AUDIO_ENABLE_FEEDBACK_EP
-      // Prepare feedback computation if endpoint is available
-      if (audio->ep_fb != 0) {
-        audio_feedback_params_t fb_param;
-
-        tud_audio_feedback_params_cb(func_id, alt, &fb_param);
-        audio->feedback.compute_method = fb_param.method;
-
-        if (TUSB_SPEED_FULL == tud_speed_get())
-          audio->feedback.format_correction = tud_audio_feedback_format_correction_cb(func_id);
-
-        // Minimal/Maximum value in 16.16 format for full speed (1ms per frame) or high speed (125 us per frame)
-        uint32_t const frame_div = (TUSB_SPEED_FULL == tud_speed_get()) ? 1000 : 8000;
-        audio->feedback.min_value = ((fb_param.sample_freq - 1) / frame_div) << 16;
-        audio->feedback.max_value = (fb_param.sample_freq / frame_div + 1) << 16;
-
-        switch (fb_param.method) {
-          case AUDIO_FEEDBACK_METHOD_FREQUENCY_FIXED:
-          case AUDIO_FEEDBACK_METHOD_FREQUENCY_FLOAT:
-          case AUDIO_FEEDBACK_METHOD_FREQUENCY_POWER_OF_2:
-            audiod_set_fb_params_freq(audio, fb_param.sample_freq, fb_param.frequency.mclk_freq);
-            break;
-
-          case AUDIO_FEEDBACK_METHOD_FIFO_COUNT: {
-            // Initialize the threshold level to half filled
-            uint16_t fifo_lvl_thr = tu_fifo_depth(&audio->ep_out_ff) / 2;
-            audio->feedback.compute.fifo_count.fifo_lvl_thr = fifo_lvl_thr;
-            audio->feedback.compute.fifo_count.fifo_lvl_avg = ((uint32_t) fifo_lvl_thr) << 16;
-            // Avoid 64bit division
-            uint32_t nominal = ((fb_param.sample_freq / 100) << 16) / (frame_div / 100);
-            audio->feedback.compute.fifo_count.nom_value = nominal;
-            audio->feedback.compute.fifo_count.rate_const[0] = (uint16_t) ((audio->feedback.max_value - nominal) / fifo_lvl_thr);
-            audio->feedback.compute.fifo_count.rate_const[1] = (uint16_t) ((nominal - audio->feedback.min_value) / fifo_lvl_thr);
-            // On HS feedback is more sensitive since packet size can vary every MSOF, could cause instability
-            if (tud_speed_get() == TUSB_SPEED_HIGH) {
-              audio->feedback.compute.fifo_count.rate_const[0] /= 8;
-              audio->feedback.compute.fifo_count.rate_const[1] /= 8;
-            }
-          } break;
-
-          // nothing to do
-          default:
-            break;
-        }
-      }
+      // Prepare feedback computation parameters
+      TU_VERIFY(audiod_fb_params_prepare(func_id, alt));
 #endif// CFG_TUD_AUDIO_ENABLE_FEEDBACK_EP
 
       // We are done - abort loop
@@ -1276,20 +1312,23 @@ static bool audiod_control_complete(uint8_t rhport, tusb_control_request_t const
           TU_VERIFY(audiod_verify_entity_exists(itf, entityID, &func_id));
 
 #if CFG_TUD_AUDIO_ENABLE_EP_IN && CFG_TUD_AUDIO_EP_IN_FLOW_CONTROL
-          uint8_t ctrlSel = TU_U16_HIGH(p_request->wValue);
-          if (_audiod_fct[func_id].bclock_id_tx == entityID && ctrlSel == AUDIO_CS_CTRL_SAM_FREQ && p_request->bRequest == AUDIO_CS_REQ_CUR) {
-            _audiod_fct[func_id].sample_rate_tx = tu_unaligned_read32(_audiod_fct[func_id].ctrl_buf);
+          if (tud_audio_n_version(func_id) == 2) {
+            uint8_t ctrlSel = TU_U16_HIGH(p_request->wValue);
+            if (_audiod_fct[func_id].bclock_id_tx == entityID && ctrlSel == AUDIO20_CS_CTRL_SAM_FREQ && p_request->bRequest == AUDIO20_CS_REQ_CUR) {
+              _audiod_fct[func_id].sample_rate_tx = tu_unaligned_read32(ctrl_buf);
+              audiod_calc_tx_packet_sz(&_audiod_fct[func_id]);
+            }
           }
 #endif
 
           // Invoke callback
-          return tud_audio_set_req_entity_cb(rhport, p_request, _audiod_fct[func_id].ctrl_buf);
+          return tud_audio_set_req_entity_cb(rhport, p_request, ctrl_buf);
         } else {
           // Find index of audio driver structure and verify interface really exists
           TU_VERIFY(audiod_verify_itf_exists(itf, &func_id));
 
           // Invoke callback
-          return tud_audio_set_req_itf_cb(rhport, p_request, _audiod_fct[func_id].ctrl_buf);
+          return tud_audio_set_req_itf_cb(rhport, p_request, ctrl_buf);
         }
       } break;
 
@@ -1299,8 +1338,32 @@ static bool audiod_control_complete(uint8_t rhport, tusb_control_request_t const
         // Check if entity is present and get corresponding driver index
         TU_VERIFY(audiod_verify_ep_exists(ep, &func_id));
 
-        // Invoke callback
-        return tud_audio_set_req_ep_cb(rhport, p_request, _audiod_fct[func_id].ctrl_buf);
+#if CFG_TUD_AUDIO_ENABLE_EP_IN && CFG_TUD_AUDIO_EP_IN_FLOW_CONTROL
+          if (tud_audio_n_version(func_id) == 1) {
+            if (_audiod_fct[func_id].ep_in == ep) {
+              uint8_t ctrlSel = TU_U16_HIGH(p_request->wValue);
+              if (ctrlSel == AUDIO10_EP_CTRL_SAMPLING_FREQ && p_request->bRequest == AUDIO10_CS_REQ_SET_CUR) {
+                _audiod_fct[func_id].sample_rate_tx = tu_unaligned_read32(ctrl_buf) & 0x00FFFFFF;
+                audiod_calc_tx_packet_sz(&_audiod_fct[func_id]);
+              }
+            }
+          }
+#endif
+
+          // Invoke callback
+          bool ret = tud_audio_set_req_ep_cb(rhport, p_request, ctrl_buf);
+
+#if CFG_TUD_AUDIO_ENABLE_EP_OUT && CFG_TUD_AUDIO_ENABLE_FEEDBACK_EP
+          if (ret && tud_audio_n_version(func_id) == 1) {
+            if (_audiod_fct[func_id].ep_out == ep) {
+              uint8_t ctrlSel = TU_U16_HIGH(p_request->wValue);
+              if (ctrlSel == AUDIO10_EP_CTRL_SAMPLING_FREQ && p_request->bRequest == AUDIO10_CS_REQ_SET_CUR) {
+                audiod_fb_params_prepare(func_id, _audiod_fct[func_id].ep_out_alt);
+              }
+            }
+          }
+#endif
+        return ret;
       } break;
       // Unknown/Unsupported recipient
       default:
@@ -1385,7 +1448,7 @@ static bool audiod_control_request(uint8_t rhport, tusb_control_request_t const
     }
 
     // If we end here, the received request is a set request - we schedule a receive for the data stage and return true here. We handle the rest later in audiod_control_complete() once the data stage was finished
-    TU_VERIFY(tud_control_xfer(rhport, p_request, _audiod_fct[func_id].ctrl_buf, _audiod_fct[func_id].ctrl_buf_sz));
+    TU_VERIFY(tud_control_xfer(rhport, p_request, ctrl_buf, sizeof(ctrl_buf)));
     return true;
   }
 
@@ -1399,6 +1462,8 @@ bool audiod_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb_control_request_
     return audiod_control_request(rhport, request);
   } else if (stage == CONTROL_STAGE_DATA) {
     return audiod_control_complete(rhport, request);
+  } else {
+    // nothing to do
   }
 
   return true;
@@ -1422,7 +1487,7 @@ bool audiod_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint3
       // I assume here, that things above are handled by PHY
       // All transmission is done - what remains to do is to inform job was completed
 
-      tud_audio_int_xfer_cb(rhport);
+      tud_audio_int_done_cb(rhport);
       return true;
     }
 
@@ -1473,7 +1538,7 @@ bool audiod_xfer_isr(uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint
     if (audio->ep_fb == ep_addr) {
       // Schedule a transmit with the new value if EP is not busy
       // Schedule next transmission - value is changed bytud_audio_n_fb_set() in the meantime or the old value gets sent
-      audiod_fb_send(audio);
+      audiod_fb_send(func_id, true);
       return true;
     }
   #endif
@@ -1485,30 +1550,72 @@ bool audiod_xfer_isr(uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint
 
 #if CFG_TUD_AUDIO_ENABLE_EP_OUT && CFG_TUD_AUDIO_ENABLE_FEEDBACK_EP
 
-static bool audiod_set_fb_params_freq(audiod_function_t *audio, uint32_t sample_freq, uint32_t mclk_freq) {
-  // Check if frame interval is within sane limits
-  // The interval value n_frames was taken from the descriptors within audiod_set_interface()
+static bool audiod_fb_params_prepare(uint8_t func_id, uint8_t alt) {
+  audiod_function_t *audio = &_audiod_fct[func_id];
 
-  // n_frames_min is ceil(2^10 * f_s / f_m) for full speed and ceil(2^13 * f_s / f_m) for high speed
-  // this lower limit ensures the measures feedback value has sufficient precision
-  uint32_t const k = (TUSB_SPEED_FULL == tud_speed_get()) ? 10 : 13;
-  uint32_t const n_frame = (1UL << audio->feedback.frame_shift);
+  // Prepare feedback computation if endpoint is available
+  if (audio->ep_fb != 0) {
+    audio_feedback_params_t fb_param = {0};
 
-  if ((((1UL << k) * sample_freq / mclk_freq) + 1) > n_frame) {
-    TU_LOG1("  UAC2 feedback interval too small\r\n");
-    TU_BREAKPOINT();
-    return false;
-  }
+    tud_audio_feedback_params_cb(func_id, alt, &fb_param);
+    audio->feedback.compute_method = fb_param.method;
 
-  // Check if parameters really allow for a power of two division
-  if ((mclk_freq % sample_freq) == 0 && tu_is_power_of_two(mclk_freq / sample_freq)) {
-    audio->feedback.compute_method = AUDIO_FEEDBACK_METHOD_FREQUENCY_POWER_OF_2;
-    audio->feedback.compute.power_of_2 = (uint8_t) (16 - (audio->feedback.frame_shift - 1) - tu_log2(mclk_freq / sample_freq));
-  } else if (audio->feedback.compute_method == AUDIO_FEEDBACK_METHOD_FREQUENCY_FLOAT) {
-    audio->feedback.compute.float_const = (float) sample_freq / (float) mclk_freq * (1UL << (16 - (audio->feedback.frame_shift - 1)));
-  } else {
-    audio->feedback.compute.fixed.sample_freq = sample_freq;
-    audio->feedback.compute.fixed.mclk_freq = mclk_freq;
+    // Minimal/Maximum value in 16.16 format for full speed (1ms per frame) or high speed (125 us per frame)
+    uint32_t const frame_div = (TUSB_SPEED_FULL == tud_speed_get()) ? 1000 : 8000;
+    audio->feedback.min_value = ((fb_param.sample_freq - 1) / frame_div) << 16;
+    audio->feedback.max_value = (fb_param.sample_freq / frame_div + 1) << 16;
+
+    switch (fb_param.method) {
+      case AUDIO_FEEDBACK_METHOD_FREQUENCY_FIXED:
+      case AUDIO_FEEDBACK_METHOD_FREQUENCY_FLOAT:
+      case AUDIO_FEEDBACK_METHOD_FREQUENCY_POWER_OF_2: {
+        // Check if frame interval is within sane limits
+        // The interval value n_frames was taken from the descriptors within audiod_set_interface()
+
+        // n_frames_min is ceil(2^10 * f_s / f_m) for full speed and ceil(2^13 * f_s / f_m) for high speed
+        // this lower limit ensures the measures feedback value has sufficient precision
+        uint32_t const k = (TUSB_SPEED_FULL == tud_speed_get()) ? 10 : 13;
+        uint32_t const n_frame = (1UL << audio->feedback.frame_shift);
+
+        if ((((1UL << k) * fb_param.sample_freq / fb_param.frequency.mclk_freq) + 1) > n_frame) {
+          TU_LOG1("  UAC2 feedback interval too small\r\n");
+          TU_BREAKPOINT();
+          return false;
+        }
+
+        // Check if parameters really allow for a power of two division
+        if ((fb_param.frequency.mclk_freq % fb_param.sample_freq) == 0 && tu_is_power_of_two(fb_param.frequency.mclk_freq / fb_param.sample_freq)) {
+          audio->feedback.compute_method = AUDIO_FEEDBACK_METHOD_FREQUENCY_POWER_OF_2;
+          audio->feedback.compute.power_of_2 = (uint8_t) (16 - (audio->feedback.frame_shift - 1) - tu_log2(fb_param.frequency.mclk_freq / fb_param.sample_freq));
+        } else if (audio->feedback.compute_method == AUDIO_FEEDBACK_METHOD_FREQUENCY_FLOAT) {
+          audio->feedback.compute.float_const = (float) fb_param.sample_freq / (float) fb_param.frequency.mclk_freq * (1UL << (16 - (audio->feedback.frame_shift - 1)));
+        } else {
+          audio->feedback.compute.fixed.sample_freq = fb_param.sample_freq;
+          audio->feedback.compute.fixed.mclk_freq = fb_param.frequency.mclk_freq;
+        }
+      } break;
+
+      case AUDIO_FEEDBACK_METHOD_FIFO_COUNT: {
+        // Determine FIFO threshold
+        uint16_t fifo_threshold = fb_param.fifo_count.fifo_threshold ? fb_param.fifo_count.fifo_threshold : tu_fifo_depth(&audio->ep_out_ff) / 2;
+        audio->feedback.compute.fifo_count.fifo_lvl_thr = fifo_threshold;
+        audio->feedback.compute.fifo_count.fifo_lvl_avg = ((uint32_t) fifo_threshold) << 16;
+        // Avoid 64bit division
+        uint32_t nominal = ((fb_param.sample_freq / 100) << 16) / (frame_div / 100);
+        audio->feedback.compute.fifo_count.nom_value = nominal;
+        audio->feedback.compute.fifo_count.rate_const[0] = (uint16_t) ((audio->feedback.max_value - nominal) / fifo_threshold);
+        audio->feedback.compute.fifo_count.rate_const[1] = (uint16_t) ((nominal - audio->feedback.min_value) / fifo_threshold);
+        // On HS feedback is more sensitive since packet size can vary every MSOF, could cause instability
+        if (tud_speed_get() == TUSB_SPEED_HIGH) {
+          audio->feedback.compute.fifo_count.rate_const[0] /= 8;
+          audio->feedback.compute.fifo_count.rate_const[1] /= 8;
+        }
+      } break;
+
+      // nothing to do
+      default:
+        break;
+    }
   }
 
   return true;
@@ -1532,52 +1639,15 @@ static void audiod_fb_fifo_count_update(audiod_function_t *audio, uint16_t lvl_n
     feedback = audio->feedback.compute.fifo_count.nom_value - (ff_lvl - ff_thr) * rate[1];
   }
 
-  if (feedback > audio->feedback.max_value) feedback = audio->feedback.max_value;
-  if (feedback < audio->feedback.min_value) feedback = audio->feedback.min_value;
-  audio->feedback.value = feedback;
-}
-
-uint32_t tud_audio_feedback_update(uint8_t func_id, uint32_t cycles) {
-  audiod_function_t *audio = &_audiod_fct[func_id];
-  uint32_t feedback;
-
-  switch (audio->feedback.compute_method) {
-    case AUDIO_FEEDBACK_METHOD_FREQUENCY_POWER_OF_2:
-      feedback = (cycles << audio->feedback.compute.power_of_2);
-      break;
-
-    case AUDIO_FEEDBACK_METHOD_FREQUENCY_FLOAT:
-      feedback = (uint32_t) ((float) cycles * audio->feedback.compute.float_const);
-      break;
-
-    case AUDIO_FEEDBACK_METHOD_FREQUENCY_FIXED: {
-      uint64_t fb64 = (((uint64_t) cycles) * audio->feedback.compute.fixed.sample_freq) << (16 - (audio->feedback.frame_shift - 1));
-      feedback = (uint32_t) (fb64 / audio->feedback.compute.fixed.mclk_freq);
-    } break;
-
-    default:
-      return 0;
+  if (feedback > audio->feedback.max_value) {
+    feedback = audio->feedback.max_value;
   }
-
-  // For Windows: https://docs.microsoft.com/en-us/windows-hardware/drivers/audio/usb-2-0-audio-drivers
-  // The size of isochronous packets created by the device must be within the limits specified in FMT-2.0 section 2.3.1.1.
-  // This means that the deviation of actual packet size from nominal size must not exceed +/- one audio slot
-  // (audio slot = channel count samples).
-  if (feedback > audio->feedback.max_value) feedback = audio->feedback.max_value;
-  if (feedback < audio->feedback.min_value) feedback = audio->feedback.min_value;
-
-  tud_audio_n_fb_set(func_id, feedback);
-
-  return feedback;
+  if (feedback < audio->feedback.min_value) {
+    feedback = audio->feedback.min_value;
+  }
+  audio->feedback.value = feedback;
 }
 
-bool tud_audio_n_fb_set(uint8_t func_id, uint32_t feedback) {
-  TU_VERIFY(func_id < CFG_TUD_AUDIO && _audiod_fct[func_id].p_desc != NULL);
-
-  _audiod_fct[func_id].feedback.value = feedback;
-
-  return true;
-}
 #endif
 
 TU_ATTR_FAST_FUNC void audiod_sof_isr(uint8_t rhport, uint32_t frame_count) {
@@ -1645,24 +1715,27 @@ bool tud_audio_buffer_and_schedule_control_xfer(uint8_t rhport, tusb_control_req
   }
 
   // Crop length
-  if (len > _audiod_fct[func_id].ctrl_buf_sz) len = _audiod_fct[func_id].ctrl_buf_sz;
+  if (len > sizeof(ctrl_buf)) len = sizeof(ctrl_buf);
 
   // Copy into buffer
-  TU_VERIFY(0 == tu_memcpy_s(_audiod_fct[func_id].ctrl_buf, _audiod_fct[func_id].ctrl_buf_sz, data, (size_t) len));
+  TU_VERIFY(0 == tu_memcpy_s(ctrl_buf, sizeof(ctrl_buf), data, (size_t) len));
 
 #if CFG_TUD_AUDIO_ENABLE_EP_IN && CFG_TUD_AUDIO_EP_IN_FLOW_CONTROL
-  // Find data for sampling_frequency_control
-  if (p_request->bmRequestType_bit.type == TUSB_REQ_TYPE_CLASS && p_request->bmRequestType_bit.recipient == TUSB_REQ_RCPT_INTERFACE) {
-    uint8_t entityID = TU_U16_HIGH(p_request->wIndex);
-    uint8_t ctrlSel = TU_U16_HIGH(p_request->wValue);
-    if (_audiod_fct[func_id].bclock_id_tx == entityID && ctrlSel == AUDIO_CS_CTRL_SAM_FREQ && p_request->bRequest == AUDIO_CS_REQ_CUR) {
-      _audiod_fct[func_id].sample_rate_tx = tu_unaligned_read32(_audiod_fct[func_id].ctrl_buf);
+  if (tud_audio_n_version(func_id) == 2) {
+    // Find data for sampling_frequency_control
+    if (p_request->bmRequestType_bit.type == TUSB_REQ_TYPE_CLASS && p_request->bmRequestType_bit.recipient == TUSB_REQ_RCPT_INTERFACE) {
+      uint8_t entityID = TU_U16_HIGH(p_request->wIndex);
+      uint8_t ctrlSel = TU_U16_HIGH(p_request->wValue);
+      if (_audiod_fct[func_id].bclock_id_tx == entityID && ctrlSel == AUDIO20_CS_CTRL_SAM_FREQ && p_request->bRequest == AUDIO20_CS_REQ_CUR) {
+        _audiod_fct[func_id].sample_rate_tx = tu_unaligned_read32(ctrl_buf);
+        audiod_calc_tx_packet_sz(&_audiod_fct[func_id]);
+      }
     }
   }
 #endif
 
   // Schedule transmit
-  return tud_control_xfer(rhport, p_request, (void *) _audiod_fct[func_id].ctrl_buf, len);
+  return tud_control_xfer(rhport, p_request, ctrl_buf, len);
 }
 
 // Verify an entity with the given ID exists and returns also the corresponding driver index
@@ -1673,11 +1746,9 @@ static bool audiod_verify_entity_exists(uint8_t itf, uint8_t entityID, uint8_t *
     if (_audiod_fct[i].p_desc && ((tusb_desc_interface_t const *) _audiod_fct[i].p_desc)->bInterfaceNumber == itf) {
       // Get pointers after class specific AC descriptors and end of AC descriptors - entities are defined in between
       uint8_t const *p_desc = tu_desc_next(_audiod_fct[i].p_desc);// Points to CS AC descriptor
-      uint8_t const *p_desc_end = ((audio_desc_cs_ac_interface_t const *) p_desc)->wTotalLength + p_desc;
       p_desc = tu_desc_next(p_desc);// Get past CS AC descriptor
 
-      // Condition modified from p_desc < p_desc_end to prevent gcc>=12 strict-overflow warning
-      while (p_desc_end - p_desc > 0) {
+      while (_audiod_fct[i].p_desc_as - p_desc > 0) {
         // Entity IDs are always at offset 3
         if (p_desc[3] == entityID) {
           *func_id = i;
@@ -1693,10 +1764,10 @@ static bool audiod_verify_entity_exists(uint8_t itf, uint8_t entityID, uint8_t *
 static bool audiod_verify_itf_exists(uint8_t itf, uint8_t *func_id) {
   uint8_t i;
   for (i = 0; i < CFG_TUD_AUDIO; i++) {
-    if (_audiod_fct[i].p_desc) {
+    if (_audiod_fct[i].p_desc != NULL) {
       // Get pointer at beginning and end
       uint8_t const *p_desc = _audiod_fct[i].p_desc;
-      uint8_t const *p_desc_end = _audiod_fct[i].p_desc + _audiod_fct[i].desc_length - TUD_AUDIO_DESC_IAD_LEN;
+      uint8_t const *p_desc_end = _audiod_fct[i].p_desc + _audiod_fct[i].desc_length;
       // Condition modified from p_desc < p_desc_end to prevent gcc>=12 strict-overflow warning
       while (p_desc_end - p_desc > 0) {
         if (tu_desc_type(p_desc) == TUSB_DESC_INTERFACE && ((tusb_desc_interface_t const *)p_desc)->bInterfaceNumber == itf) {
@@ -1718,8 +1789,7 @@ static bool audiod_verify_ep_exists(uint8_t ep, uint8_t *func_id) {
       uint8_t const *p_desc_end = _audiod_fct[i].p_desc + _audiod_fct[i].desc_length;
 
       // Advance past AC descriptors - EP we look for are streaming EPs
-      uint8_t const *p_desc = tu_desc_next(_audiod_fct[i].p_desc);
-      p_desc += ((audio_desc_cs_ac_interface_t const *) p_desc)->wTotalLength;
+      uint8_t const *p_desc = _audiod_fct[i].p_desc_as;
 
       // Condition modified from p_desc < p_desc_end to prevent gcc>=12 strict-overflow warning
       while (p_desc_end - p_desc > 0) {
@@ -1739,20 +1809,34 @@ static void audiod_parse_flow_control_params(audiod_function_t *audio, uint8_t c
 
   p_desc = tu_desc_next(p_desc);// Exclude standard AS interface descriptor of current alternate interface descriptor
 
-  // Look for a Class-Specific AS Interface Descriptor(4.9.2) to verify format type and format and also to get number of physical channels
-  if (tu_desc_type(p_desc) == TUSB_DESC_CS_INTERFACE && tu_desc_subtype(p_desc) == AUDIO_CS_AS_INTERFACE_AS_GENERAL) {
-    audio->n_channels_tx = ((audio_desc_cs_as_interface_t const *) p_desc)->bNrChannels;
-    audio->format_type_tx = (audio_format_type_t) (((audio_desc_cs_as_interface_t const *) p_desc)->bFormatType);
-    // Look for a Type I Format Type Descriptor(2.3.1.6 - Audio Formats)
-    p_desc = tu_desc_next(p_desc);
-    if (tu_desc_type(p_desc) == TUSB_DESC_CS_INTERFACE && tu_desc_subtype(p_desc) == AUDIO_CS_AS_INTERFACE_FORMAT_TYPE && ((audio_desc_type_I_format_t const *) p_desc)->bFormatType == AUDIO_FORMAT_TYPE_I) {
-      audio->n_bytes_per_sample_tx = ((audio_desc_type_I_format_t const *) p_desc)->bSubslotSize;
+  if (tud_audio_n_version(audiod_get_audio_fct_idx(audio)) == 1) {
+    p_desc = tu_desc_next(p_desc);// Exclude Class-Specific AS Interface Descriptor(4.5.2) to get to format type descriptor
+    if (tu_desc_type(p_desc) == TUSB_DESC_CS_INTERFACE && tu_desc_subtype(p_desc) == AUDIO10_CS_AS_INTERFACE_FORMAT_TYPE) {
+      audio->format_type_tx = ((audio10_desc_type_I_format_n_t(1) const *) p_desc)->bFormatType;
+      if (audio->format_type_tx == AUDIO10_FORMAT_TYPE_I) {
+        audio->n_channels_tx = ((audio10_desc_type_I_format_n_t(1) const *) p_desc)->bNrChannels;
+        audio->n_bytes_per_sample_tx = ((audio10_desc_type_I_format_n_t(1) const *) p_desc)->bSubFrameSize;
+        // Save sample rate - needed when EP doesn't support setting sample rate
+        audio->sample_rate_tx = tu_unaligned_read32(((audio10_desc_type_I_format_n_t(1) const *) p_desc)->tSamFreq) & 0x00FFFFFF;
+      }
+    }
+  } else {
+    // Look for a Class-Specific AS Interface Descriptor(4.9.2) to verify format type and format and also to get number of physical channels
+    if (tu_desc_type(p_desc) == TUSB_DESC_CS_INTERFACE && tu_desc_subtype(p_desc) == AUDIO20_CS_AS_INTERFACE_AS_GENERAL) {
+      audio->n_channels_tx = ((audio20_desc_cs_as_interface_t const *) p_desc)->bNrChannels;
+      audio->format_type_tx = ((audio20_desc_cs_as_interface_t const *) p_desc)->bFormatType;
+      // Look for a Type I Format Type Descriptor(2.3.1.6 - Audio Formats)
+      p_desc = tu_desc_next(p_desc);
+      if (tu_desc_type(p_desc) == TUSB_DESC_CS_INTERFACE && tu_desc_subtype(p_desc) == AUDIO20_CS_AS_INTERFACE_FORMAT_TYPE && ((audio20_desc_type_I_format_t const *) p_desc)->bFormatType == AUDIO20_FORMAT_TYPE_I) {
+        audio->n_bytes_per_sample_tx = ((audio20_desc_type_I_format_t const *) p_desc)->bSubslotSize;
+      }
     }
   }
 }
 
 static bool audiod_calc_tx_packet_sz(audiod_function_t *audio) {
-  TU_VERIFY(audio->format_type_tx == AUDIO_FORMAT_TYPE_I);
+  // AUDIO20_FORMAT_TYPE_I = AUDIO10_FORMAT_TYPE_I
+  TU_VERIFY(audio->format_type_tx == AUDIO20_FORMAT_TYPE_I);
   TU_VERIFY(audio->n_channels_tx);
   TU_VERIFY(audio->n_bytes_per_sample_tx);
   TU_VERIFY(audio->interval_tx);
@@ -1787,22 +1871,22 @@ static bool audiod_calc_tx_packet_sz(audiod_function_t *audio) {
   return true;
 }
 
-static uint16_t audiod_tx_packet_size(const uint16_t *norminal_size, uint16_t data_count, uint16_t fifo_depth, uint16_t max_depth) {
+static uint16_t audiod_tx_packet_size(const uint16_t *nominal_size, uint16_t data_count, uint16_t fifo_depth, uint16_t fifo_threshold, uint16_t max_depth) {
   // Flow control need a FIFO size of at least 4*Navg
-  if (norminal_size[1] && norminal_size[1] <= fifo_depth * 4) {
+  if (nominal_size[1] && nominal_size[1] <= fifo_depth * 4) {
     // Use blackout to prioritize normal size packet
     static int ctrl_blackout = 0;
     uint16_t packet_size;
-    uint16_t slot_size = norminal_size[2] - norminal_size[1];
-    if (data_count < norminal_size[0]) {
+    uint16_t slot_size = nominal_size[2] - nominal_size[1];
+    if (data_count < nominal_size[0]) {
       // If you get here frequently, then your I2S clock deviation is too big !
       packet_size = 0;
-    } else if (data_count < fifo_depth / 2 - slot_size && !ctrl_blackout) {
-      packet_size = norminal_size[0];
+    } else if (data_count < (fifo_threshold - slot_size) && !ctrl_blackout) {
+      packet_size = nominal_size[0];
       ctrl_blackout = 10;
-    } else if (data_count > fifo_depth / 2 + slot_size && !ctrl_blackout) {
-      packet_size = norminal_size[2];
-      if (norminal_size[0] == norminal_size[1]) {
+    } else if (data_count > (fifo_threshold + slot_size) && !ctrl_blackout) {
+      packet_size = nominal_size[2];
+      if (nominal_size[0] == nominal_size[1]) {
         // nav > INT(nav), eg. 44.1k, 88.2k
         ctrl_blackout = 0;
       } else {
@@ -1810,7 +1894,7 @@ static uint16_t audiod_tx_packet_size(const uint16_t *norminal_size, uint16_t da
         ctrl_blackout = 10;
       }
     } else {
-      packet_size = norminal_size[1];
+      packet_size = nominal_size[1];
       if (ctrl_blackout) {
         ctrl_blackout--;
       }
@@ -1825,11 +1909,8 @@ static uint16_t audiod_tx_packet_size(const uint16_t *norminal_size, uint16_t da
 #endif
 
 // No security checks here - internal function only which should always succeed
-static uint8_t audiod_get_audio_fct_idx(audiod_function_t *audio) {
-  for (uint8_t cnt = 0; cnt < CFG_TUD_AUDIO; cnt++) {
-    if (&_audiod_fct[cnt] == audio) return cnt;
-  }
-  return 0;
+static inline uint8_t audiod_get_audio_fct_idx(audiod_function_t *audio) {
+  return (uint8_t) (audio - _audiod_fct);
 }
 
 #endif // (CFG_TUD_ENABLED && CFG_TUD_AUDIO)
diff --git a/src/class/audio/audio_device.h b/src/class/audio/audio_device.h
index fd47c649d..1e0c46915 100644
--- a/src/class/audio/audio_device.h
+++ b/src/class/audio/audio_device.h
@@ -37,35 +37,10 @@
 
 // All sizes are in bytes!
 
-#ifndef CFG_TUD_AUDIO_FUNC_1_DESC_LEN
-#error You must tell the driver the length of the audio function descriptor including IAD descriptor
-#endif
-#if CFG_TUD_AUDIO > 1
-#ifndef CFG_TUD_AUDIO_FUNC_2_DESC_LEN
-#error You must tell the driver the length of the audio function descriptor including IAD descriptor
-#endif
-#endif
-#if CFG_TUD_AUDIO > 2
-#ifndef CFG_TUD_AUDIO_FUNC_3_DESC_LEN
-#error You must tell the driver the length of the audio function descriptor including IAD descriptor
-#endif
-#endif
-
-// Size of control buffer used to receive and send control messages via EP0 - has to be big enough to hold your biggest request structure e.g. range requests with multiple intervals defined or cluster descriptors
-#ifndef CFG_TUD_AUDIO_FUNC_1_CTRL_BUF_SZ
-#error You must define an audio class control request buffer size!
-#endif
-
-#if CFG_TUD_AUDIO > 1
-#ifndef CFG_TUD_AUDIO_FUNC_2_CTRL_BUF_SZ
-#error You must define an audio class control request buffer size!
-#endif
-#endif
-
-#if CFG_TUD_AUDIO > 2
-#ifndef CFG_TUD_AUDIO_FUNC_3_CTRL_BUF_SZ
-#error You must define an audio class control request buffer size!
-#endif
+// Size of control buffer used to receive and send control messages via EP0 - has to be big enough to hold your
+// biggest request structure e.g. range requests with multiple intervals defined or cluster descriptors
+#ifndef CFG_TUD_AUDIO_CTRL_BUF_SZ
+#define CFG_TUD_AUDIO_CTRL_BUF_SZ    64
 #endif
 
 // End point sizes IN BYTES - Limits: Full Speed <= 1023, High Speed <= 1024
@@ -167,7 +142,8 @@
 #endif
 #endif
 
-// (For TYPE-I format only) Flow control is necessary to allow IN ep send correct amount of data, unless it's a virtual device where data is perfectly synchronized to USB clock.
+// (For TYPE-I format only) Flow control is necessary to allow IN ep send correct amount of data, unless it's a
+// virtual device where data is perfectly synchronized to USB clock.
 #ifndef CFG_TUD_AUDIO_EP_IN_FLOW_CONTROL
 #define CFG_TUD_AUDIO_EP_IN_FLOW_CONTROL  1
 #endif
@@ -177,12 +153,6 @@
 #define CFG_TUD_AUDIO_ENABLE_FEEDBACK_EP                    0                             // Feedback - 0 or 1
 #endif
 
-// Enable/disable conversion from 16.16 to 10.14 format on full-speed devices. See tud_audio_n_fb_set().
-// Can be override by tud_audio_feedback_format_correction_cb()
-#ifndef CFG_TUD_AUDIO_ENABLE_FEEDBACK_FORMAT_CORRECTION
-#define CFG_TUD_AUDIO_ENABLE_FEEDBACK_FORMAT_CORRECTION     0                             // 0 or 1
-#endif
-
 // Enable/disable interrupt EP (required for notifying host of control changes)
 #ifndef CFG_TUD_AUDIO_ENABLE_INTERRUPT_EP
 #define CFG_TUD_AUDIO_ENABLE_INTERRUPT_EP                   0                             // Feedback - 0 or 1
@@ -205,6 +175,7 @@ extern "C" {
 // CFG_TUD_AUDIO > 1
 //--------------------------------------------------------------------+
 bool tud_audio_n_mounted(uint8_t func_id);
+uint8_t tud_audio_n_version(uint8_t func_id);
 
 #if CFG_TUD_AUDIO_ENABLE_EP_OUT
 uint16_t   tud_audio_n_available       (uint8_t func_id);
@@ -217,6 +188,8 @@ tu_fifo_t* tud_audio_n_get_ep_out_ff   (uint8_t func_id);
 uint16_t   tud_audio_n_write          (uint8_t func_id, const void * data, uint16_t len);
 bool       tud_audio_n_clear_ep_in_ff (uint8_t func_id);
 tu_fifo_t* tud_audio_n_get_ep_in_ff   (uint8_t func_id);
+uint16_t   tud_audio_n_get_ep_in_fifo_threshold(uint8_t func_id);
+void       tud_audio_n_set_ep_in_fifo_threshold(uint8_t func_id, uint16_t threshold);
 #endif
 
 #if CFG_TUD_AUDIO_ENABLE_INTERRUPT_EP
@@ -227,6 +200,7 @@ bool    tud_audio_int_n_write                     (uint8_t func_id, const audio_
 // Application API (Interface0)
 //--------------------------------------------------------------------+
 static inline bool         tud_audio_mounted                (void);
+static inline uint8_t      tud_audio_version                (void);
 
 #if CFG_TUD_AUDIO_ENABLE_EP_OUT
 static inline uint16_t   tud_audio_available       (void);
@@ -248,12 +222,15 @@ static inline bool tud_audio_int_write                      (const audio_interru
 #endif
 
 // Buffer control EP data and schedule a transmit
-// This function is intended to be used if you do not have a persistent buffer or memory location available (e.g. non-local variables) and need to answer onto a
-// get request. This function buffers your answer request frame into the control buffer of the corresponding audio driver and schedules a transmit for sending it.
-// Since transmission is triggered via interrupts, a persistent memory location is required onto which the buffer pointer in pointing. If you already have such
-// available you may directly use 'tud_control_xfer(...)'. In this case data does not need to be copied into an additional buffer and you save some time.
+// This function is intended to be used if you do not have a persistent buffer or memory location available
+// (e.g. non-local variables) and need to answer onto a get request. This function buffers your answer request
+// frame into the control buffer of the corresponding audio driver and schedules a transmit for sending it.
+// Since transmission is triggered via interrupts, a persistent memory location is required onto which the buffer
+// pointer in pointing. If you already have such available you may directly use 'tud_control_xfer(...)'. In this
+// case data does not need to be copied into an additional buffer and you save some time.
 // If the request's wLength is zero, a status packet is sent instead.
-bool tud_audio_buffer_and_schedule_control_xfer(uint8_t rhport, tusb_control_request_t const * p_request, void* data, uint16_t len);
+bool tud_audio_buffer_and_schedule_control_xfer(uint8_t rhport, tusb_control_request_t const * p_request,
+                                                 void* data, uint16_t len);
 
 //--------------------------------------------------------------------+
 // Application Callback API
@@ -261,14 +238,18 @@ bool tud_audio_buffer_and_schedule_control_xfer(uint8_t rhport, tusb_control_req
 
 #if CFG_TUD_AUDIO_ENABLE_EP_IN
 // Invoked in ISR context once an audio packet was sent successfully.
-// Normally this function is not needed, since the data transfer should be driven by audio clock (i.e. I2S clock), call tud_audio_write() in I2S receive callback.
-bool tud_audio_tx_done_isr(uint8_t rhport, uint16_t n_bytes_sent, uint8_t func_id, uint8_t ep_in, uint8_t cur_alt_setting);
+// Normally this function is not needed, since the data transfer should be driven by audio clock (i.e. I2S clock),
+// call tud_audio_write() in I2S receive callback.
+bool tud_audio_tx_done_isr(uint8_t rhport, uint16_t n_bytes_sent, uint8_t func_id, uint8_t ep_in,
+                           uint8_t cur_alt_setting);
 #endif
 
 #if CFG_TUD_AUDIO_ENABLE_EP_OUT
 // Invoked in ISR context once an audio packet was received successfully.
-// Normally this function is not needed, since the data transfer should be driven by audio clock (i.e. I2S clock), call tud_audio_read() in I2S transmit callback.
-bool tud_audio_rx_done_isr(uint8_t rhport, uint16_t n_bytes_received, uint8_t func_id, uint8_t ep_out, uint8_t cur_alt_setting);
+// Normally this function is not needed, since the data transfer should be driven by audio clock (i.e. I2S clock),
+// call tud_audio_read() in I2S transmit callback.
+bool tud_audio_rx_done_isr(uint8_t rhport, uint16_t n_bytes_received, uint8_t func_id, uint8_t ep_out,
+                           uint8_t cur_alt_setting);
 #endif
 
 #if CFG_TUD_AUDIO_ENABLE_EP_OUT && CFG_TUD_AUDIO_ENABLE_FEEDBACK_EP
@@ -277,42 +258,55 @@ bool tud_audio_rx_done_isr(uint8_t rhport, uint16_t n_bytes_received, uint8_t fu
 //
 // Option 1 - AUDIO_FEEDBACK_METHOD_FIFO_COUNT
 // Feedback value is calculated within the audio driver by regulating the FIFO level to half fill.
-// Advantage: No ISR interrupt is enabled, hence the CPU need not to handle an ISR every 1ms or 125us and thus less CPU load, well tested
-// (Windows, Linux, OSX) with a reliable result so far.
-// Disadvantage: A FIFO of minimal 4 frames is needed to compensate for jitter, an average delay of 2 frames is introduced.
+// Advantage: No SOF interrupt is enabled, hence the CPU need not to handle an ISR every 1ms or 125us and thus
+// less CPU load, well tested (Windows, Linux, OSX) with a reliable result so far.
+// Disadvantage: A FIFO of minimal 4 frames is needed to compensate for jitter, an average delay of 2 frames is
+// introduced.
 //
 // Option 2 - AUDIO_FEEDBACK_METHOD_FREQUENCY_FIXED / AUDIO_FEEDBACK_METHOD_FREQUENCY_FLOAT
-// Feedback value is calculated within the audio driver by use of SOF interrupt. The driver needs information about the master clock f_m from
-// which the audio sample frequency f_s is derived, f_s itself, and the cycle count of f_m at time of the SOF interrupt (e.g. by use of a hardware counter).
+// Feedback value is calculated within the audio driver by use of SOF interrupt. The driver needs information
+// about the master clock f_m from which the audio sample frequency f_s is derived, f_s itself, and the cycle
+// count of f_m at time of the SOF interrupt (e.g. by use of a hardware counter).
 // See tud_audio_set_fb_params() and tud_audio_feedback_update()
-// Advantage: Reduced jitter in the feedback value computation, hence, the receive FIFO can be smaller and thus a smaller delay is possible.
-// Disadvantage: higher CPU load due to SOF ISR handling every frame i.e. 1ms or 125us. (The most critical point is the reading of the cycle counter value of f_m.
-// It is read from within the SOF ISR - see: audiod_sof() -, hence, the ISR must has a high priority such that no software dependent "random" delay i.e. jitter is introduced).
-// Long-term drift could occur since error is accumulated.
+// Advantage: Reduced jitter in the feedback value computation, hence, the receive FIFO can be smaller and thus a
+// smaller delay is possible.
+// Disadvantage: higher CPU load due to SOF ISR handling every frame i.e. 1ms or 125us. (The most critical point
+// is the reading of the cycle counter value of f_m. It is read from within the SOF ISR - see: audiod_sof() -,
+// hence, the ISR must has a high priority such that no software dependent "random" delay i.e. jitter is
+// introduced). Long-term drift will cause the FIFO under/overflow, you still needs to correct it somehow.
 //
 // Option 3 - manual
-// Determined by the user itself and set by use of tud_audio_n_fb_set(). The feedback value may be determined e.g. from some fill status of some FIFO buffer.
-// Advantage: No ISR interrupt is enabled, hence the CPU need not to handle an ISR every 1ms or 125us and thus less CPU load.
-// Disadvantage: typically a larger FIFO is needed to compensate for jitter (e.g. 6 frames), i.e. a larger delay is introduced.
+// Determined by the user itself and set by use of tud_audio_n_fb_set(). The feedback value may be determined
+// e.g. from some fill status of some FIFO buffer.
+// Advantage: No ISR interrupt is enabled, hence the CPU need not to handle an ISR every 1ms or 125us and thus
+// less CPU load.
+// Disadvantage: typically a larger FIFO is needed to compensate for jitter (e.g. 6 frames), i.e. a larger delay
+// is introduced.
 
 
-// This function is used to provide data rate feedback from an asynchronous sink. Feedback value will be sent at FB endpoint interval till it's changed.
+// This function is used to provide data rate feedback from an asynchronous sink. Feedback value will be sent at
+// FB endpoint interval till it's changed.
 //
-// The feedback format is specified to be 16.16 for HS and 10.14 for FS devices (see Universal Serial Bus Specification Revision 2.0 5.12.4.2). By default,
-// the choice of format is left to the caller and feedback argument is sent as-is. If CFG_TUD_AUDIO_ENABLE_FEEDBACK_FORMAT_CORRECTION is set or tud_audio_feedback_format_correction_cb()
-// return true, then tinyusb expects 16.16 format and handles the conversion to 10.14 on FS.
+// The feedback format is specified to be 16.16 for HS and 10.14 for FS devices (see Universal Serial Bus
+// Specification Revision 2.0 5.12.4.2). For simplicity, this function always uses 16.16 format. For FS devices,
+// the driver will automatically convert the value to 10.14 format.
 //
-// Note that due to a bug in its USB Audio 2.0 driver, Windows currently requires 16.16 format for _all_ USB 2.0 devices. On Linux and it seems the
-// driver can work with either format.
+// Note that due to a bug in its USB Audio 2.0 driver, Windows currently requires 16.16 format for _all_ USB 2.0
+// devices. On Linux and it seems the driver can work with either format.
 //
-// Feedback value can be determined from within the SOF ISR of the audio driver. This should reduce jitter. If the feature is used, the user can not set the feedback value.
+// Feedback value can be determined from within the SOF ISR of the audio driver. This should reduce jitter. If the
+// feature is used, the user can not set the feedback value.
 //
 // Determine feedback value - The feedback method is described in 5.12.4.2 of the USB 2.0 spec
 // Boiled down, the feedback value Ff = n_samples / (micro)frame.
-// Since an accuracy of less than 1 Sample / second is desired, at least n_frames = ceil(2^K * f_s / f_m) frames need to be measured, where K = 10 for full speed and K = 13
-// for high speed, f_s is the sampling frequency e.g. 48 kHz and f_m is the cpu clock frequency e.g. 100 MHz (or any other master clock whose clock count is available and locked to f_s)
-// The update interval in the (4.10.2.1) Feedback Endpoint Descriptor must be less or equal to 2^(K - P), where P = min( ceil(log2(f_m / f_s)), K)
-// feedback = n_cycles / n_frames * f_s / f_m in 16.16 format, where n_cycles are the number of main clock cycles within fb_n_frames
+// Since an accuracy of less than 1 Sample / second is desired, at least n_frames = ceil(2^K * f_s / f_m) frames
+// need to be measured, where K = 10 for full speed and K = 13 for high speed, f_s is the sampling frequency
+// e.g. 48 kHz and f_m is the cpu clock frequency e.g. 100 MHz (or any other master clock whose clock count is
+// available and locked to f_s)
+// The update interval in the (4.10.2.1) Feedback Endpoint Descriptor must be less or equal to 2^(K - P), where
+// P = min( ceil(log2(f_m / f_s)), K)
+// feedback = n_cycles / n_frames * f_s / f_m in 16.16 format, where n_cycles are the number of main clock cycles
+// within fb_n_frames
 bool tud_audio_n_fb_set(uint8_t func_id, uint32_t feedback);
 
 // Update feedback value with passed MCLK cycles since last time this update function is called.
@@ -339,10 +333,12 @@ typedef struct {
   union {
     struct {
       uint32_t mclk_freq; // Main clock frequency in Hz i.e. master clock to which sample clock is based on
-    }frequency;
-
+    } frequency;
+    struct {
+      uint16_t fifo_threshold;  // Target FIFO threshold level, default to half FIFO if not set
+    } fifo_count;
   };
-}audio_feedback_params_t;
+} audio_feedback_params_t;
 
 // Invoked when needed to set feedback parameters
 void tud_audio_feedback_params_cb(uint8_t func_id, uint8_t alt_itf, audio_feedback_params_t* feedback_param);
@@ -352,13 +348,10 @@ void tud_audio_feedback_params_cb(uint8_t func_id, uint8_t alt_itf, audio_feedba
 // frame_number  : current SOF count
 // interval_shift: number of bit shift i.e log2(interval) from Feedback endpoint descriptor
 TU_ATTR_FAST_FUNC void tud_audio_feedback_interval_isr(uint8_t func_id, uint32_t frame_number, uint8_t interval_shift);
-
-// (Full-Speed only) Callback to set feedback format correction is applied or not,
-// default to CFG_TUD_AUDIO_ENABLE_FEEDBACK_FORMAT_CORRECTION if not implemented.
-bool tud_audio_feedback_format_correction_cb(uint8_t func_id);
 #endif // CFG_TUD_AUDIO_ENABLE_EP_OUT && CFG_TUD_AUDIO_ENABLE_FEEDBACK_EP
 
 #if CFG_TUD_AUDIO_ENABLE_INTERRUPT_EP
+// Invoked when an interrupt notification transfer is complete
 void tud_audio_int_done_cb(uint8_t rhport);
 #endif
 
@@ -397,6 +390,10 @@ TU_ATTR_ALWAYS_INLINE static inline bool tud_audio_mounted(void) {
   return tud_audio_n_mounted(0);
 }
 
+TU_ATTR_ALWAYS_INLINE static inline uint8_t tud_audio_version(void) {
+  return tud_audio_n_version(0);
+}
+
 #if CFG_TUD_AUDIO_ENABLE_EP_OUT
 
 TU_ATTR_ALWAYS_INLINE static inline uint16_t tud_audio_available(void) {
@@ -431,6 +428,16 @@ TU_ATTR_ALWAYS_INLINE static inline tu_fifo_t* tud_audio_get_ep_in_ff(void) {
   return tud_audio_n_get_ep_in_ff(0);
 }
 
+TU_ATTR_ALWAYS_INLINE static inline uint16_t tud_audio_get_ep_in_fifo_threshold(void)
+{
+  return tud_audio_n_get_ep_in_fifo_threshold(0);
+}
+
+TU_ATTR_ALWAYS_INLINE static inline void tud_audio_set_ep_in_fifo_threshold(uint16_t threshold)
+{
+  tud_audio_n_set_ep_in_fifo_threshold(0, threshold);
+}
+
 #endif
 
 #if CFG_TUD_AUDIO_ENABLE_INTERRUPT_EP
@@ -461,7 +468,7 @@ void     audiod_sof_isr        (uint8_t rhport, uint32_t frame_count);
 }
 #endif
 
-#endif /* _TUSB_AUDIO_DEVICE_H_ */
+#endif /* TUSB_AUDIO_DEVICE_H_ */
 
 /** @} */
 /** @} */
diff --git a/src/class/bth/bth_device.c b/src/class/bth/bth_device.c
index 3f1529cb6..b679d6ab6 100755
--- a/src/class/bth/bth_device.c
+++ b/src/class/bth/bth_device.c
@@ -67,7 +67,7 @@ static bool bt_tx_data(uint8_t ep, void *data, uint16_t len) {
   // skip if previous transfer not complete
   TU_VERIFY(!usbd_edpt_busy(rhport, ep));
 
-  TU_ASSERT(usbd_edpt_xfer(rhport, ep, data, len));
+  TU_ASSERT(usbd_edpt_xfer(rhport, ep, data, len, false));
 
   return true;
 }
@@ -169,7 +169,7 @@ uint16_t btd_open(uint8_t rhport, tusb_desc_interface_t const *itf_desc, uint16_
   itf_desc = (tusb_desc_interface_t const *) tu_desc_next(tu_desc_next(desc_ep));
 
   // Prepare for incoming data from host
-  TU_ASSERT(usbd_edpt_xfer(rhport, _btd_itf.ep_acl_out, _btd_epbuf.epout_buf, CFG_TUD_BTH_DATA_EPSIZE), 0);
+  TU_ASSERT(usbd_edpt_xfer(rhport, _btd_itf.ep_acl_out, _btd_epbuf.epout_buf, CFG_TUD_BTH_DATA_EPSIZE, false), 0);
 
   drv_len = hci_itf_size;
 
@@ -272,7 +272,7 @@ bool btd_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t result,
     tud_bt_acl_data_received_cb(_btd_epbuf.epout_buf, xferred_bytes);
 
     // prepare for next data
-    TU_ASSERT(usbd_edpt_xfer(rhport, _btd_itf.ep_acl_out, _btd_epbuf.epout_buf, CFG_TUD_BTH_DATA_EPSIZE));
+    TU_ASSERT(usbd_edpt_xfer(rhport, _btd_itf.ep_acl_out, _btd_epbuf.epout_buf, CFG_TUD_BTH_DATA_EPSIZE, false));
   } else if (ep_addr == _btd_itf.ep_ev) {
     tud_bt_event_sent_cb((uint16_t) xferred_bytes);
   } else if (ep_addr == _btd_itf.ep_acl_in) {
diff --git a/src/class/bth/bth_device.h b/src/class/bth/bth_device.h
index 68f073bff..89a056dc8 100755
--- a/src/class/bth/bth_device.h
+++ b/src/class/bth/bth_device.h
@@ -24,8 +24,8 @@
  * This file is part of the TinyUSB stack.
  */
 
-#ifndef _TUSB_BTH_DEVICE_H_
-#define _TUSB_BTH_DEVICE_H_
+#ifndef TUSB_BTH_DEVICE_H_
+#define TUSB_BTH_DEVICE_H_
 
 #include <common/tusb_common.h>
 #include <device/usbd.h>
@@ -114,4 +114,4 @@ bool     btd_xfer_cb         (uint8_t rhport, uint8_t edpt_addr, xfer_result_t r
  }
 #endif
 
-#endif /* _TUSB_BTH_DEVICE_H_ */
+#endif /* TUSB_BTH_DEVICE_H_ */
diff --git a/src/class/cdc/cdc.h b/src/class/cdc/cdc.h
index 10ba16a7c..679723ba6 100644
--- a/src/class/cdc/cdc.h
+++ b/src/class/cdc/cdc.h
@@ -29,8 +29,8 @@
  *            Currently only Abstract Control Model subclass is supported
  *  @{ */
 
-#ifndef _TUSB_CDC_H__
-#define _TUSB_CDC_H__
+#ifndef TUSB_CDC_H__
+#define TUSB_CDC_H__
 
 #include "common/tusb_common.h"
 
@@ -192,10 +192,10 @@ typedef enum {
   CDC_LINE_CODING_STOP_BITS_2   = 2, // 2   bits
 } cdc_line_coding_stopbits_t;
 
-#define CDC_LINE_CODING_STOP_BITS_TEXT(STOP_BITS) (        \
-  STOP_BITS == CDC_LINE_CODING_STOP_BITS_1 ?   "1" :       \
-  STOP_BITS == CDC_LINE_CODING_STOP_BITS_1_5 ? "1.5" :     \
-  STOP_BITS == CDC_LINE_CODING_STOP_BITS_2 ?   "2"   : "?" )
+#define CDC_LINE_CODING_STOP_BITS_TEXT(STOP_BITS) (          \
+  (STOP_BITS) == CDC_LINE_CODING_STOP_BITS_1   ? "1" :       \
+  (STOP_BITS) == CDC_LINE_CODING_STOP_BITS_1_5 ? "1.5" :     \
+  (STOP_BITS) == CDC_LINE_CODING_STOP_BITS_2   ? "2"   : "?" )
 
 // TODO Backward compatible for typos. Maybe removed in the future release
 #define CDC_LINE_CONDING_STOP_BITS_1   CDC_LINE_CODING_STOP_BITS_1
@@ -211,11 +211,11 @@ typedef enum {
 } cdc_line_coding_parity_t;
 
 #define CDC_LINE_CODING_PARITY_CHAR(PARITY) (        \
-  PARITY == CDC_LINE_CODING_PARITY_NONE  ? 'N' :     \
-  PARITY == CDC_LINE_CODING_PARITY_ODD   ? 'O' :     \
-  PARITY == CDC_LINE_CODING_PARITY_EVEN  ? 'E' :     \
-  PARITY == CDC_LINE_CODING_PARITY_MARK  ? 'M' :     \
-  PARITY == CDC_LINE_CODING_PARITY_SPACE ? 'S' : '?' )
+  (PARITY) == CDC_LINE_CODING_PARITY_NONE  ? 'N' :     \
+  (PARITY) == CDC_LINE_CODING_PARITY_ODD   ? 'O' :     \
+  (PARITY) == CDC_LINE_CODING_PARITY_EVEN  ? 'E' :     \
+  (PARITY) == CDC_LINE_CODING_PARITY_MARK  ? 'M' :     \
+  (PARITY) == CDC_LINE_CODING_PARITY_SPACE ? 'S' : '?' )
 
 //--------------------------------------------------------------------+
 // Management Element Notification (Notification Endpoint)
diff --git a/src/class/cdc/cdc_device.c b/src/class/cdc/cdc_device.c
index f1c4a3bbf..9e62c6509 100644
--- a/src/class/cdc/cdc_device.c
+++ b/src/class/cdc/cdc_device.c
@@ -48,28 +48,23 @@
 typedef struct {
   uint8_t rhport;
   uint8_t itf_num;
-  uint8_t ep_in;
-  uint8_t ep_out;
-
   uint8_t ep_notify;
   uint8_t line_state; // Bit 0: DTR, Bit 1: RTS
 
   /*------------- From this point, data is not cleared by bus reset -------------*/
-  char wanted_char;
   TU_ATTR_ALIGNED(4) cdc_line_coding_t line_coding;
+  char wanted_char;
 
-  // FIFO
-  tu_fifo_t rx_ff;
-  tu_fifo_t tx_ff;
-
-  uint8_t rx_ff_buf[CFG_TUD_CDC_RX_BUFSIZE];
-  uint8_t tx_ff_buf[CFG_TUD_CDC_TX_BUFSIZE];
+  struct {
+    tu_edpt_stream_t tx;
+    tu_edpt_stream_t rx;
 
-  OSAL_MUTEX_DEF(rx_ff_mutex);
-  OSAL_MUTEX_DEF(tx_ff_mutex);
+    uint8_t tx_ff_buf[CFG_TUD_CDC_TX_BUFSIZE];
+    uint8_t rx_ff_buf[CFG_TUD_CDC_RX_BUFSIZE];
+  } stream;
 } cdcd_interface_t;
 
-#define ITF_MEM_RESET_SIZE   offsetof(cdcd_interface_t, wanted_char)
+#define ITF_MEM_RESET_SIZE offsetof(cdcd_interface_t, line_coding)
 
 typedef struct {
   TUD_EPBUF_DEF(epout, CFG_TUD_CDC_EP_BUFSIZE);
@@ -81,110 +76,100 @@ typedef struct {
 } cdcd_epbuf_t;
 
 //--------------------------------------------------------------------+
-// INTERNAL OBJECT & FUNCTION DECLARATION
-//--------------------------------------------------------------------+
-static cdcd_interface_t _cdcd_itf[CFG_TUD_CDC];
-CFG_TUD_MEM_SECTION static cdcd_epbuf_t _cdcd_epbuf[CFG_TUD_CDC];
-
-static tud_cdc_configure_t _cdcd_cfg = TUD_CDC_CONFIGURE_DEFAULT();
-
-static bool _prep_out_transaction(uint8_t itf) {
-  const uint8_t rhport = 0;
-  cdcd_interface_t* p_cdc = &_cdcd_itf[itf];
-  cdcd_epbuf_t* p_epbuf = &_cdcd_epbuf[itf];
-
-  // Skip if usb is not ready yet
-  TU_VERIFY(tud_ready() && p_cdc->ep_out);
-
-  uint16_t available = tu_fifo_remaining(&p_cdc->rx_ff);
-
-  // Prepare for incoming data but only allow what we can store in the ring buffer.
-  // TODO Actually we can still carry out the transfer, keeping count of received bytes
-  // and slowly move it to the FIFO when read().
-  // This pre-check reduces endpoint claiming
-  TU_VERIFY(available >= CFG_TUD_CDC_EP_BUFSIZE);
-
-  // claim endpoint
-  TU_VERIFY(usbd_edpt_claim(p_cdc->rhport, p_cdc->ep_out));
-
-  // fifo can be changed before endpoint is claimed
-  available = tu_fifo_remaining(&p_cdc->rx_ff);
-
-  if (available >= CFG_TUD_CDC_EP_BUFSIZE) {
-    return usbd_edpt_xfer(rhport, p_cdc->ep_out, p_epbuf->epout, CFG_TUD_CDC_EP_BUFSIZE);
-  } else {
-    // Release endpoint since we don't make any transfer
-    usbd_edpt_release(p_cdc->rhport, p_cdc->ep_out);
-    return false;
-  }
-}
-
-//--------------------------------------------------------------------+
 // Weak stubs: invoked if no strong implementation is available
 //--------------------------------------------------------------------+
 TU_ATTR_WEAK void tud_cdc_rx_cb(uint8_t itf) {
-  (void) itf;
+  (void)itf;
 }
 
 TU_ATTR_WEAK void tud_cdc_rx_wanted_cb(uint8_t itf, char wanted_char) {
-  (void) itf;
-  (void) wanted_char;
+  (void)itf;
+  (void)wanted_char;
 }
 
 TU_ATTR_WEAK void tud_cdc_tx_complete_cb(uint8_t itf) {
-  (void) itf;
+  (void)itf;
 }
 
 TU_ATTR_WEAK void tud_cdc_notify_complete_cb(uint8_t itf) {
-  (void) itf;
+  (void)itf;
 }
 
 TU_ATTR_WEAK void tud_cdc_line_state_cb(uint8_t itf, bool dtr, bool rts) {
-  (void) itf;
-  (void) dtr;
-  (void) rts;
+  (void)itf;
+  (void)dtr;
+  (void)rts;
 }
 
-TU_ATTR_WEAK void tud_cdc_line_coding_cb(uint8_t itf, cdc_line_coding_t const* p_line_coding) {
-  (void) itf;
-  (void) p_line_coding;
+TU_ATTR_WEAK void tud_cdc_line_coding_cb(uint8_t itf, const cdc_line_coding_t *p_line_coding) {
+  (void)itf;
+  (void)p_line_coding;
 }
 
 TU_ATTR_WEAK void tud_cdc_send_break_cb(uint8_t itf, uint16_t duration_ms) {
-  (void) itf;
-  (void) duration_ms;
+  (void)itf;
+  (void)duration_ms;
+}
+
+//--------------------------------------------------------------------+
+// INTERNAL OBJECT & FUNCTION DECLARATION
+//--------------------------------------------------------------------+
+static cdcd_interface_t _cdcd_itf[CFG_TUD_CDC];
+CFG_TUD_MEM_SECTION static cdcd_epbuf_t _cdcd_epbuf[CFG_TUD_CDC];
+static tud_cdc_configure_t _cdcd_cfg = TUD_CDC_CONFIGURE_DEFAULT();
+
+TU_ATTR_ALWAYS_INLINE static inline uint8_t find_cdc_itf(uint8_t ep_addr) {
+  for (uint8_t idx = 0; idx < CFG_TUD_CDC; idx++) {
+    const cdcd_interface_t *p_cdc = &_cdcd_itf[idx];
+    if (ep_addr == p_cdc->stream.rx.ep_addr || ep_addr == p_cdc->stream.tx.ep_addr ||
+        (ep_addr == p_cdc->ep_notify && ep_addr != 0)) {
+      return idx;
+    }
+  }
+  return TUSB_INDEX_INVALID_8;
 }
 
 //--------------------------------------------------------------------+
 // APPLICATION API
 //--------------------------------------------------------------------+
 bool tud_cdc_configure(const tud_cdc_configure_t* driver_cfg) {
-  TU_VERIFY(driver_cfg);
+  TU_VERIFY(driver_cfg != NULL);
   _cdcd_cfg = *driver_cfg;
   return true;
 }
 
 bool tud_cdc_n_ready(uint8_t itf) {
-  return tud_ready() && _cdcd_itf[itf].ep_in != 0 && _cdcd_itf[itf].ep_out != 0;
+  TU_VERIFY(itf < CFG_TUD_CDC);
+  TU_VERIFY(tud_ready());
+  const cdcd_interface_t *p_cdc = &_cdcd_itf[itf];
+
+  const bool in_opened  = tu_edpt_stream_is_opened(&p_cdc->stream.tx);
+  const bool out_opened = tu_edpt_stream_is_opened(&p_cdc->stream.rx);
+  return in_opened && out_opened;
 }
 
 bool tud_cdc_n_connected(uint8_t itf) {
+  TU_VERIFY(itf < CFG_TUD_CDC);
+  TU_VERIFY(tud_ready());
   // DTR (bit 0) active  is considered as connected
-  return tud_ready() && tu_bit_test(_cdcd_itf[itf].line_state, 0);
+  return tu_bit_test(_cdcd_itf[itf].line_state, 0);
 }
 
 uint8_t tud_cdc_n_get_line_state(uint8_t itf) {
+  TU_VERIFY(itf < CFG_TUD_CDC, 0);
   return _cdcd_itf[itf].line_state;
 }
 
-void tud_cdc_n_get_line_coding(uint8_t itf, cdc_line_coding_t* coding) {
+void tud_cdc_n_get_line_coding(uint8_t itf, cdc_line_coding_t *coding) {
+  TU_VERIFY(itf < CFG_TUD_CDC, );
   (*coding) = _cdcd_itf[itf].line_coding;
 }
 
 #if CFG_TUD_CDC_NOTIFY
 bool tud_cdc_n_notify_uart_state (uint8_t itf, const cdc_notify_uart_state_t *state) {
-  cdcd_interface_t* p_cdc = &_cdcd_itf[itf];
-  cdcd_epbuf_t* p_epbuf = &_cdcd_epbuf[itf];
+  TU_VERIFY(itf < CFG_TUD_CDC);
+  cdcd_interface_t *p_cdc   = &_cdcd_itf[itf];
+  cdcd_epbuf_t     *p_epbuf = &_cdcd_epbuf[itf];
   TU_VERIFY(tud_ready() && p_cdc->ep_notify != 0);
   TU_VERIFY(usbd_edpt_claim(p_cdc->rhport, p_cdc->ep_notify));
 
@@ -196,12 +181,13 @@ bool tud_cdc_n_notify_uart_state (uint8_t itf, const cdc_notify_uart_state_t *st
   notify_msg->request.wLength = sizeof(cdc_notify_uart_state_t);
   notify_msg->serial_state = *state;
 
-  return usbd_edpt_xfer(p_cdc->rhport, p_cdc->ep_notify, (uint8_t *)notify_msg, 8 + sizeof(cdc_notify_uart_state_t));
+  return usbd_edpt_xfer(p_cdc->rhport, p_cdc->ep_notify, (uint8_t *)notify_msg, 8 + sizeof(cdc_notify_uart_state_t), false);
 }
 
 bool tud_cdc_n_notify_conn_speed_change(uint8_t itf, const cdc_notify_conn_speed_change_t* conn_speed_change) {
-  cdcd_interface_t* p_cdc = &_cdcd_itf[itf];
-  cdcd_epbuf_t* p_epbuf = &_cdcd_epbuf[itf];
+  TU_VERIFY(itf < CFG_TUD_CDC);
+  cdcd_interface_t *p_cdc   = &_cdcd_itf[itf];
+  cdcd_epbuf_t     *p_epbuf = &_cdcd_epbuf[itf];
   TU_VERIFY(tud_ready() && p_cdc->ep_notify != 0);
   TU_VERIFY(usbd_edpt_claim(p_cdc->rhport, p_cdc->ep_notify));
 
@@ -213,11 +199,12 @@ bool tud_cdc_n_notify_conn_speed_change(uint8_t itf, const cdc_notify_conn_speed
   notify_msg->request.wLength = sizeof(cdc_notify_conn_speed_change_t);
   notify_msg->conn_speed_change = *conn_speed_change;
 
-  return usbd_edpt_xfer(p_cdc->rhport, p_cdc->ep_notify, (uint8_t *)notify_msg, 8 + sizeof(cdc_notify_conn_speed_change_t));
+  return usbd_edpt_xfer(p_cdc->rhport, p_cdc->ep_notify, (uint8_t *)notify_msg, 8 + sizeof(cdc_notify_conn_speed_change_t), false);
 }
 #endif
 
 void tud_cdc_n_set_wanted_char(uint8_t itf, char wanted) {
+  TU_VERIFY(itf < CFG_TUD_CDC, );
   _cdcd_itf[itf].wanted_char = wanted;
 }
 
@@ -225,77 +212,53 @@ void tud_cdc_n_set_wanted_char(uint8_t itf, char wanted) {
 // READ API
 //--------------------------------------------------------------------+
 uint32_t tud_cdc_n_available(uint8_t itf) {
-  return tu_fifo_count(&_cdcd_itf[itf].rx_ff);
+  TU_VERIFY(itf < CFG_TUD_CDC, 0);
+  return tu_edpt_stream_read_available(&_cdcd_itf[itf].stream.rx);
 }
 
 uint32_t tud_cdc_n_read(uint8_t itf, void* buffer, uint32_t bufsize) {
-  cdcd_interface_t* p_cdc = &_cdcd_itf[itf];
-  uint32_t num_read = tu_fifo_read_n(&p_cdc->rx_ff, buffer, (uint16_t) TU_MIN(bufsize, UINT16_MAX));
-  _prep_out_transaction(itf);
-  return num_read;
+  TU_VERIFY(itf < CFG_TUD_CDC, 0);
+  cdcd_interface_t *p_cdc = &_cdcd_itf[itf];
+  return tu_edpt_stream_read(p_cdc->rhport, &p_cdc->stream.rx, buffer, bufsize);
 }
 
-bool tud_cdc_n_peek(uint8_t itf, uint8_t* chr) {
-  return tu_fifo_peek(&_cdcd_itf[itf].rx_ff, chr);
+bool tud_cdc_n_peek(uint8_t itf, uint8_t *chr) {
+  TU_VERIFY(itf < CFG_TUD_CDC);
+  return tu_edpt_stream_peek(&_cdcd_itf[itf].stream.rx, chr);
 }
 
 void tud_cdc_n_read_flush(uint8_t itf) {
-  cdcd_interface_t* p_cdc = &_cdcd_itf[itf];
-  tu_fifo_clear(&p_cdc->rx_ff);
-  _prep_out_transaction(itf);
+  TU_VERIFY(itf < CFG_TUD_CDC, );
+  cdcd_interface_t *p_cdc = &_cdcd_itf[itf];
+  tu_edpt_stream_clear(&p_cdc->stream.rx);
+  tu_edpt_stream_read_xfer(p_cdc->rhport, &p_cdc->stream.rx);
 }
 
 //--------------------------------------------------------------------+
 // WRITE API
 //--------------------------------------------------------------------+
 uint32_t tud_cdc_n_write(uint8_t itf, const void* buffer, uint32_t bufsize) {
-  cdcd_interface_t* p_cdc = &_cdcd_itf[itf];
-  uint16_t wr_count = tu_fifo_write_n(&p_cdc->tx_ff, buffer, (uint16_t) TU_MIN(bufsize, UINT16_MAX));
-
-  // flush if queue more than packet size
-  if (tu_fifo_count(&p_cdc->tx_ff) >= BULK_PACKET_SIZE
-      #if CFG_TUD_CDC_TX_BUFSIZE < BULK_PACKET_SIZE
-      || tu_fifo_full(&p_cdc->tx_ff) // check full if fifo size is less than packet size
-      #endif
-      ) {
-    tud_cdc_n_write_flush(itf);
-  }
-
-  return wr_count;
+  TU_VERIFY(itf < CFG_TUD_CDC, 0);
+  cdcd_interface_t *p_cdc = &_cdcd_itf[itf];
+  return tu_edpt_stream_write(p_cdc->rhport, &p_cdc->stream.tx, buffer, bufsize);
 }
 
 uint32_t tud_cdc_n_write_flush(uint8_t itf) {
-  cdcd_interface_t* p_cdc = &_cdcd_itf[itf];
-  cdcd_epbuf_t* p_epbuf = &_cdcd_epbuf[itf];
-  TU_VERIFY(tud_ready(), 0); // Skip if usb is not ready yet
-
-  // No data to send
-  if (!tu_fifo_count(&p_cdc->tx_ff)) {
-    return 0;
-  }
-
-  TU_VERIFY(usbd_edpt_claim(p_cdc->rhport, p_cdc->ep_in), 0); // Claim the endpoint
-
-  // Pull data from FIFO
-  const uint16_t count = tu_fifo_read_n(&p_cdc->tx_ff, p_epbuf->epin, CFG_TUD_CDC_EP_BUFSIZE);
-
-  if (count) {
-    TU_ASSERT(usbd_edpt_xfer(p_cdc->rhport, p_cdc->ep_in, p_epbuf->epin, count), 0);
-    return count;
-  } else {
-    // Release endpoint since we don't make any transfer
-    // Note: data is dropped if terminal is not connected
-    usbd_edpt_release(p_cdc->rhport, p_cdc->ep_in);
-    return 0;
-  }
+  TU_VERIFY(itf < CFG_TUD_CDC, 0);
+  cdcd_interface_t *p_cdc = &_cdcd_itf[itf];
+  return tu_edpt_stream_write_xfer(p_cdc->rhport, &p_cdc->stream.tx);
 }
 
 uint32_t tud_cdc_n_write_available(uint8_t itf) {
-  return tu_fifo_remaining(&_cdcd_itf[itf].tx_ff);
+  TU_VERIFY(itf < CFG_TUD_CDC, 0);
+  cdcd_interface_t *p_cdc = &_cdcd_itf[itf];
+  return tu_edpt_stream_write_available(p_cdc->rhport, &p_cdc->stream.tx);
 }
 
 bool tud_cdc_n_write_clear(uint8_t itf) {
-  return tu_fifo_clear(&_cdcd_itf[itf].tx_ff);
+  TU_VERIFY(itf < CFG_TUD_CDC);
+  cdcd_interface_t *p_cdc = &_cdcd_itf[itf];
+  return tu_edpt_stream_clear(&p_cdc->stream.tx);
 }
 
 //--------------------------------------------------------------------+
@@ -304,7 +267,8 @@ bool tud_cdc_n_write_clear(uint8_t itf) {
 void cdcd_init(void) {
   tu_memclr(_cdcd_itf, sizeof(_cdcd_itf));
   for (uint8_t i = 0; i < CFG_TUD_CDC; i++) {
-    cdcd_interface_t* p_cdc = &_cdcd_itf[i];
+    cdcd_interface_t *p_cdc   = &_cdcd_itf[i];
+    cdcd_epbuf_t     *p_epbuf = &_cdcd_epbuf[i];
 
     p_cdc->wanted_char = (char) -1;
 
@@ -314,44 +278,23 @@ void cdcd_init(void) {
     p_cdc->line_coding.parity = 0;
     p_cdc->line_coding.data_bits = 8;
 
-    // Config RX fifo
-    tu_fifo_config(&p_cdc->rx_ff, p_cdc->rx_ff_buf, TU_ARRAY_SIZE(p_cdc->rx_ff_buf), 1, false);
+    tu_edpt_stream_init(&p_cdc->stream.rx, false, false, false, p_cdc->stream.rx_ff_buf, CFG_TUD_CDC_RX_BUFSIZE,
+                        p_epbuf->epout, CFG_TUD_CDC_EP_BUFSIZE);
 
     // TX fifo can be configured to change to overwritable if not connected (DTR bit not set). Without DTR we do not
     // know if data is actually polled by terminal. This way the most current data is prioritized.
     // Default: is overwritable
-    tu_fifo_config(&p_cdc->tx_ff, p_cdc->tx_ff_buf, TU_ARRAY_SIZE(p_cdc->tx_ff_buf), 1, _cdcd_cfg.tx_overwritabe_if_not_connected);
-
-    #if OSAL_MUTEX_REQUIRED
-    osal_mutex_t mutex_rd = osal_mutex_create(&p_cdc->rx_ff_mutex);
-    osal_mutex_t mutex_wr = osal_mutex_create(&p_cdc->tx_ff_mutex);
-    TU_ASSERT(mutex_rd != NULL && mutex_wr != NULL, );
-
-    tu_fifo_config_mutex(&p_cdc->rx_ff, NULL, mutex_rd);
-    tu_fifo_config_mutex(&p_cdc->tx_ff, mutex_wr, NULL);
-    #endif
+    tu_edpt_stream_init(&p_cdc->stream.tx, false, true, _cdcd_cfg.tx_overwritabe_if_not_connected,
+                        p_cdc->stream.tx_ff_buf, CFG_TUD_CDC_TX_BUFSIZE, p_epbuf->epin, CFG_TUD_CDC_EP_BUFSIZE);
   }
 }
 
 bool cdcd_deinit(void) {
-  #if OSAL_MUTEX_REQUIRED
-  for(uint8_t i=0; i<CFG_TUD_CDC; i++) {
+  for (uint8_t i = 0; i < CFG_TUD_CDC; i++) {
     cdcd_interface_t* p_cdc = &_cdcd_itf[i];
-    osal_mutex_t mutex_rd = p_cdc->rx_ff.mutex_rd;
-    osal_mutex_t mutex_wr = p_cdc->tx_ff.mutex_wr;
-
-    if (mutex_rd) {
-      osal_mutex_delete(mutex_rd);
-      tu_fifo_config_mutex(&p_cdc->rx_ff, NULL, NULL);
-    }
-
-    if (mutex_wr) {
-      osal_mutex_delete(mutex_wr);
-      tu_fifo_config_mutex(&p_cdc->tx_ff, NULL, NULL);
-    }
+    tu_edpt_stream_deinit(&p_cdc->stream.rx);
+    tu_edpt_stream_deinit(&p_cdc->stream.tx);
   }
-  #endif
-
   return true;
 }
 
@@ -360,74 +303,85 @@ void cdcd_reset(uint8_t rhport) {
 
   for (uint8_t i = 0; i < CFG_TUD_CDC; i++) {
     cdcd_interface_t* p_cdc = &_cdcd_itf[i];
-
     tu_memclr(p_cdc, ITF_MEM_RESET_SIZE);
-    if (!_cdcd_cfg.rx_persistent) {
-      tu_fifo_clear(&p_cdc->rx_ff);
-    }
-    if (!_cdcd_cfg.tx_persistent) {
-      tu_fifo_clear(&p_cdc->tx_ff);
-    }
-    tu_fifo_set_overwritable(&p_cdc->tx_ff, _cdcd_cfg.tx_overwritabe_if_not_connected);
+
+    tu_fifo_set_overwritable(&p_cdc->stream.tx.ff, _cdcd_cfg.tx_overwritabe_if_not_connected); // back to default
+    tu_edpt_stream_close(&p_cdc->stream.rx);
+    tu_edpt_stream_close(&p_cdc->stream.tx);
   }
 }
 
 uint16_t cdcd_open(uint8_t rhport, const tusb_desc_interface_t* itf_desc, uint16_t max_len) {
   // Only support ACM subclass
-  TU_VERIFY( TUSB_CLASS_CDC                           == itf_desc->bInterfaceClass &&
-             CDC_COMM_SUBCLASS_ABSTRACT_CONTROL_MODEL == itf_desc->bInterfaceSubClass, 0);
+  TU_VERIFY(TUSB_CLASS_CDC == itf_desc->bInterfaceClass &&
+              CDC_COMM_SUBCLASS_ABSTRACT_CONTROL_MODEL == itf_desc->bInterfaceSubClass,
+            0);
 
-  // Find available interface
-  cdcd_interface_t* p_cdc;
-  uint8_t cdc_id;
-  for (cdc_id = 0; cdc_id < CFG_TUD_CDC; cdc_id++) {
-    p_cdc = &_cdcd_itf[cdc_id];
-    if (p_cdc->ep_in == 0) {
-      break;
-    }
-  }
+  const uint8_t cdc_id = find_cdc_itf(0); // Find available interface
   TU_ASSERT(cdc_id < CFG_TUD_CDC, 0);
+  cdcd_interface_t *p_cdc = &_cdcd_itf[cdc_id];
 
   //------------- Control Interface -------------//
   p_cdc->rhport = rhport;
   p_cdc->itf_num = itf_desc->bInterfaceNumber;
 
-  uint16_t drv_len = sizeof(tusb_desc_interface_t);
-  const uint8_t* p_desc = tu_desc_next(itf_desc);
+  const uint8_t *p_desc   = (const uint8_t *)itf_desc;
+  const uint8_t *desc_end = p_desc + max_len;
 
-  // Communication Functional Descriptors
-  while (TUSB_DESC_CS_INTERFACE == tu_desc_type(p_desc) && drv_len <= max_len) {
-    drv_len += tu_desc_len(p_desc);
+  // Skip all class-specific descriptor
+  p_desc = tu_desc_next(itf_desc);
+  while (tu_desc_in_bounds(p_desc, desc_end) && TUSB_DESC_CS_INTERFACE == tu_desc_type(p_desc)) {
     p_desc = tu_desc_next(p_desc);
   }
 
+  // notification endpoint (optional)
   if (TUSB_DESC_ENDPOINT == tu_desc_type(p_desc)) {
-    // notification endpoint
     const tusb_desc_endpoint_t* desc_ep = (const tusb_desc_endpoint_t*) p_desc;
     TU_ASSERT(usbd_edpt_open(rhport, desc_ep), 0);
     p_cdc->ep_notify = desc_ep->bEndpointAddress;
 
-    drv_len += tu_desc_len(p_desc);
     p_desc = tu_desc_next(p_desc);
   }
 
-  //------------- Data Interface (if any) -------------//
-  if ((TUSB_DESC_INTERFACE == tu_desc_type(p_desc)) &&
-      (TUSB_CLASS_CDC_DATA == ((const tusb_desc_interface_t*) p_desc)->bInterfaceClass)) {
-    // next to endpoint descriptor
-    drv_len += tu_desc_len(p_desc);
-    p_desc = tu_desc_next(p_desc);
+  //------------- Data Interface (optional) -------------//
+  if (TUSB_DESC_INTERFACE == tu_desc_type(p_desc)) {
+    const tusb_desc_interface_t *data_itf_desc = (const tusb_desc_interface_t *)p_desc;
+    if (TUSB_CLASS_CDC_DATA == data_itf_desc->bInterfaceClass) {
+      for (uint8_t e = 0; e < data_itf_desc->bNumEndpoints; e++) {
+        if (!tu_desc_in_bounds(p_desc, desc_end)) {
+          break;
+        }
+        p_desc = tu_desc_next(p_desc);
 
-    // Open endpoint pair
-    TU_ASSERT(usbd_open_edpt_pair(rhport, p_desc, 2, TUSB_XFER_BULK, &p_cdc->ep_out, &p_cdc->ep_in), 0);
+        const tusb_desc_endpoint_t *desc_ep = (const tusb_desc_endpoint_t *)p_desc;
+        TU_ASSERT(TUSB_DESC_ENDPOINT == desc_ep->bDescriptorType && TUSB_XFER_BULK == desc_ep->bmAttributes.xfer, 0);
 
-    drv_len += 2 * sizeof(tusb_desc_endpoint_t);
-  }
+        TU_ASSERT(usbd_edpt_open(rhport, desc_ep), 0);
+        if (tu_edpt_dir(desc_ep->bEndpointAddress) == TUSB_DIR_IN) {
+          tu_edpt_stream_t *stream_tx = &p_cdc->stream.tx;
 
-  // Prepare for incoming data
-  _prep_out_transaction(cdc_id);
+          tu_edpt_stream_open(stream_tx, desc_ep);
+          if (_cdcd_cfg.tx_persistent) {
+            tu_edpt_stream_write_xfer(rhport, stream_tx); // flush pending data
+          } else {
+            tu_edpt_stream_clear(stream_tx);
+          }
+        } else {
+          tu_edpt_stream_t *stream_rx = &p_cdc->stream.rx;
 
-  return drv_len;
+          tu_edpt_stream_open(stream_rx, desc_ep);
+          if (!_cdcd_cfg.rx_persistent) {
+            tu_edpt_stream_clear(stream_rx);
+          }
+          TU_ASSERT(tu_edpt_stream_read_xfer(rhport, stream_rx) > 0, 0); // prepare for incoming data
+        }
+      }
+
+      p_desc = tu_desc_next(p_desc);
+    }
+  }
+
+  return (uint16_t)(p_desc - (const uint8_t *)itf_desc);
 }
 
 // Invoked when a control transfer occurred on an interface of this class
@@ -456,6 +410,8 @@ bool cdcd_control_xfer_cb(uint8_t rhport, uint8_t stage, const tusb_control_requ
         tud_control_xfer(rhport, request, &p_cdc->line_coding, sizeof(cdc_line_coding_t));
       } else if (stage == CONTROL_STAGE_ACK) {
         tud_cdc_line_coding_cb(itf, &p_cdc->line_coding);
+      } else {
+        // nothing to do
       }
       break;
 
@@ -482,15 +438,15 @@ bool cdcd_control_xfer_cb(uint8_t rhport, uint8_t stage, const tusb_control_requ
 
         // If enabled: fifo overwriting is disabled if DTR bit is set and vice versa
         if (_cdcd_cfg.tx_overwritabe_if_not_connected) {
-          tu_fifo_set_overwritable(&p_cdc->tx_ff, !dtr);
+          tu_fifo_set_overwritable(&p_cdc->stream.tx.ff, !dtr);
         } else {
-          tu_fifo_set_overwritable(&p_cdc->tx_ff, false);
+          tu_fifo_set_overwritable(&p_cdc->stream.tx.ff, false);
         }
 
         TU_LOG_DRV("  Set Control Line State: DTR = %d, RTS = %d\r\n", dtr, rts);
-
-        // Invoke callback
-        tud_cdc_line_state_cb(itf, dtr, rts);
+        tud_cdc_line_state_cb(itf, dtr, rts); // invoke callback
+      } else {
+        // nothing to do
       }
       break;
 
@@ -500,6 +456,8 @@ bool cdcd_control_xfer_cb(uint8_t rhport, uint8_t stage, const tusb_control_requ
       } else if (stage == CONTROL_STAGE_ACK) {
         TU_LOG_DRV("  Send Break\r\n");
         tud_cdc_send_break_cb(itf, request->wValue);
+      } else {
+        // nothing to do
       }
       break;
 
@@ -511,58 +469,45 @@ bool cdcd_control_xfer_cb(uint8_t rhport, uint8_t stage, const tusb_control_requ
 }
 
 bool cdcd_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint32_t xferred_bytes) {
-  (void) result;
+  (void)result;
 
-  uint8_t itf;
-  cdcd_interface_t* p_cdc;
-
-  // Identify which interface to use
-  for (itf = 0; itf < CFG_TUD_CDC; itf++) {
-    p_cdc = &_cdcd_itf[itf];
-    if ((ep_addr == p_cdc->ep_out) || (ep_addr == p_cdc->ep_in) || (ep_addr == p_cdc->ep_notify)) {
-      break;
-    }
-  }
+  uint8_t itf = find_cdc_itf(ep_addr);
   TU_ASSERT(itf < CFG_TUD_CDC);
-  cdcd_epbuf_t* p_epbuf = &_cdcd_epbuf[itf];
+  cdcd_interface_t *p_cdc     = &_cdcd_itf[itf];
+  tu_edpt_stream_t *stream_rx = &p_cdc->stream.rx;
+  tu_edpt_stream_t *stream_tx = &p_cdc->stream.tx;
 
-  // Received new data
-  if (ep_addr == p_cdc->ep_out) {
-    tu_fifo_write_n(&p_cdc->rx_ff, p_epbuf->epout, (uint16_t) xferred_bytes);
+  // Received new data, move to fifo
+  if (ep_addr == stream_rx->ep_addr) {
+    tu_edpt_stream_read_xfer_complete(stream_rx, xferred_bytes);
 
-    // Check for wanted char and invoke callback if needed
-    if (((signed char) p_cdc->wanted_char) != -1) {
+    // Check for wanted char and invoke wanted callback (multiple times if multiple wanted received)
+    if (((signed char)p_cdc->wanted_char) != -1) {
       for (uint32_t i = 0; i < xferred_bytes; i++) {
-        if ((p_cdc->wanted_char == p_epbuf->epout[i]) && !tu_fifo_empty(&p_cdc->rx_ff)) {
+        if ((p_cdc->wanted_char == (char)stream_rx->ep_buf[i]) && !tu_edpt_stream_empty(stream_rx)) {
           tud_cdc_rx_wanted_cb(itf, p_cdc->wanted_char);
         }
       }
     }
 
-    // invoke receive callback (if there is still data)
-    if (!tu_fifo_empty(&p_cdc->rx_ff)) {
+    // invoke receive callback if there is still data
+    if (!tu_edpt_stream_empty(stream_rx)) {
       tud_cdc_rx_cb(itf);
     }
 
-    // prepare for OUT transaction
-    _prep_out_transaction(itf);
+    tu_edpt_stream_read_xfer(rhport, stream_rx); // prepare for more data
   }
 
   // Data sent to host, we continue to fetch from tx fifo to send.
   // Note: This will cause incorrect baudrate set in line coding.
   //       Though maybe the baudrate is not really important !!!
-  if (ep_addr == p_cdc->ep_in) {
+  if (ep_addr == stream_tx->ep_addr) {
     // invoke transmit callback to possibly refill tx fifo
     tud_cdc_tx_complete_cb(itf);
 
-    if (0 == tud_cdc_n_write_flush(itf)) {
-      // If there is no data left, a ZLP should be sent if
-      // xferred_bytes is multiple of EP Packet size and not zero
-      if (!tu_fifo_count(&p_cdc->tx_ff) && xferred_bytes && (0 == (xferred_bytes & (BULK_PACKET_SIZE - 1)))) {
-        if (usbd_edpt_claim(rhport, p_cdc->ep_in)) {
-          TU_ASSERT(usbd_edpt_xfer(rhport, p_cdc->ep_in, NULL, 0));
-        }
-      }
+    if (0 == tu_edpt_stream_write_xfer(rhport, stream_tx)) {
+      // If there is no data left, a ZLP should be sent if needed
+      tu_edpt_stream_write_zlp_if_needed(rhport, stream_tx, xferred_bytes);
     }
   }
 
diff --git a/src/class/cdc/cdc_device.h b/src/class/cdc/cdc_device.h
index 9673b9807..6f21af4f3 100644
--- a/src/class/cdc/cdc_device.h
+++ b/src/class/cdc/cdc_device.h
@@ -53,15 +53,16 @@
 // Driver Configuration
 //--------------------------------------------------------------------+
 typedef struct TU_ATTR_PACKED {
-  uint8_t rx_persistent : 1; // keep rx fifo data even with bus reset or disconnect
-  uint8_t tx_persistent : 1; // keep tx fifo data even with reset or disconnect
-  uint8_t tx_overwritabe_if_not_connected : 1; // if not connected, tx fifo can be overwritten
+  bool rx_persistent : 1; // keep rx fifo data even with bus reset or disconnect
+  bool tx_persistent : 1; // keep tx fifo data even with reset or disconnect
+  bool tx_overwritabe_if_not_connected : 1; // if not connected, tx fifo can be overwritten
 } tud_cdc_configure_t;
+TU_VERIFY_STATIC(sizeof(tud_cdc_configure_t) == 1, "size is not correct");
 
 #define TUD_CDC_CONFIGURE_DEFAULT() { \
-  .rx_persistent = 0, \
-  .tx_persistent = 0, \
-  .tx_overwritabe_if_not_connected = 1, \
+  .rx_persistent = false, \
+  .tx_persistent = false, \
+  .tx_overwritabe_if_not_connected = true, \
 }
 
 // Configure CDC driver behavior
@@ -257,4 +258,4 @@ bool     cdcd_xfer_cb         (uint8_t rhport, uint8_t ep_addr, xfer_result_t re
  }
 #endif
 
-#endif /* _TUSB_CDC_DEVICE_H_ */
+#endif /* TUSB_CDC_DEVICE_H_ */
diff --git a/src/class/cdc/cdc_host.c b/src/class/cdc/cdc_host.c
index beef03eff..35717ddf6 100644
--- a/src/class/cdc/cdc_host.c
+++ b/src/class/cdc/cdc_host.c
@@ -298,6 +298,7 @@ TU_VERIFY_STATIC(TU_ARRAY_SIZE(serial_drivers) == SERIAL_DRIVER_COUNT, "Serial d
 //--------------------------------------------------------------------+
 // INTERNAL OBJECT & FUNCTION DECLARATION
 //--------------------------------------------------------------------+
+static bool open_ep_stream_pair(cdch_interface_t *p_cdc, const tusb_desc_endpoint_t *desc_ep);
 
 TU_ATTR_ALWAYS_INLINE static inline cdch_interface_t * get_itf(uint8_t idx) {
   TU_ASSERT(idx < CFG_TUH_CDC, NULL);
@@ -364,7 +365,7 @@ static cdch_interface_t* get_itf_by_xfer(const tuh_xfer_t * xfer) {
         #endif
 
         default:
-          break;
+          break; // unknown driver
       }
     }
   }
@@ -389,8 +390,6 @@ static cdch_interface_t * make_new_itf(uint8_t daddr, tusb_desc_interface_t cons
   return NULL;
 }
 
-static bool open_ep_stream_pair(cdch_interface_t * p_cdc , tusb_desc_endpoint_t const *desc_ep);
-
 //--------------------------------------------------------------------+
 // Weak stubs: invoked if no strong implementation is available
 //--------------------------------------------------------------------+
@@ -519,7 +518,7 @@ bool tuh_cdc_read_clear (uint8_t idx) {
   TU_VERIFY(p_cdc);
 
   bool ret = tu_edpt_stream_clear(&p_cdc->stream.rx);
-  tu_edpt_stream_read_xfer(p_cdc->daddr, &p_cdc->stream.rx);
+  (void)tu_edpt_stream_read_xfer(p_cdc->daddr, &p_cdc->stream.rx);
   return ret;
 }
 
@@ -602,7 +601,7 @@ bool tuh_cdc_set_line_coding(uint8_t idx, cdc_line_coding_t const *line_coding,
   p_cdc->requested_line.coding = *line_coding;
   p_cdc->user_complete_cb = complete_cb;
 
-  if (driver->set_line_coding) {
+  if (driver->set_line_coding != NULL) {
     // driver support set_line_coding request
     TU_VERIFY(driver->set_line_coding(p_cdc, complete_cb ? cdch_internal_control_complete : NULL, user_data));
 
@@ -611,7 +610,7 @@ bool tuh_cdc_set_line_coding(uint8_t idx, cdc_line_coding_t const *line_coding,
     }
   } else {
     // driver does not support set_line_coding and need 2 stage to set baudrate and data format separately
-    if (complete_cb) {
+    if (complete_cb != NULL) {
       // non-blocking
       TU_VERIFY(driver->set_baudrate(p_cdc, cdch_set_line_coding_stage1_baudrate_complete, user_data));
     } else {
@@ -619,7 +618,7 @@ bool tuh_cdc_set_line_coding(uint8_t idx, cdc_line_coding_t const *line_coding,
       xfer_result_t result = XFER_RESULT_INVALID;
 
       TU_VERIFY(driver->set_baudrate(p_cdc, NULL, (uintptr_t) &result));
-      if (user_data) {
+      if (user_data != 0) {
         *((xfer_result_t *) user_data) = result;
       }
       TU_VERIFY(result == XFER_RESULT_SUCCESS);
@@ -627,7 +626,7 @@ bool tuh_cdc_set_line_coding(uint8_t idx, cdc_line_coding_t const *line_coding,
 
       result = XFER_RESULT_INVALID;
       TU_VERIFY(driver->set_data_format(p_cdc, NULL, (uintptr_t) &result));
-      if (user_data) {
+      if (user_data != 0) {
         *((xfer_result_t *) user_data) = result;
       }
       TU_VERIFY(result == XFER_RESULT_SUCCESS);
@@ -648,13 +647,10 @@ bool cdch_init(void) {
   for (size_t i = 0; i < CFG_TUH_CDC; i++) {
     cdch_interface_t *p_cdc = &cdch_data[i];
     cdch_epbuf_t *epbuf = &cdch_epbuf[i];
-    tu_edpt_stream_init(&p_cdc->stream.tx, true, true, false,
-                        p_cdc->stream.tx_ff_buf, CFG_TUH_CDC_TX_BUFSIZE,
-                        epbuf->tx, CFG_TUH_CDC_TX_EPSIZE);
-
-    tu_edpt_stream_init(&p_cdc->stream.rx, true, false, false,
-                        p_cdc->stream.rx_ff_buf, CFG_TUH_CDC_RX_BUFSIZE,
-                        epbuf->rx, CFG_TUH_CDC_RX_EPSIZE);
+    TU_ASSERT(tu_edpt_stream_init(&p_cdc->stream.tx, true, true, false, p_cdc->stream.tx_ff_buf, CFG_TUH_CDC_TX_BUFSIZE,
+                                  epbuf->tx, CFG_TUH_CDC_TX_EPSIZE));
+    TU_ASSERT(tu_edpt_stream_init(&p_cdc->stream.rx, true, false, false, p_cdc->stream.rx_ff_buf,
+                                  CFG_TUH_CDC_RX_BUFSIZE, epbuf->rx, CFG_TUH_CDC_RX_EPSIZE));
   }
 
   return true;
@@ -663,8 +659,8 @@ bool cdch_init(void) {
 bool cdch_deinit(void) {
   for (size_t i = 0; i < CFG_TUH_CDC; i++) {
     cdch_interface_t *p_cdc = &cdch_data[i];
-    tu_edpt_stream_deinit(&p_cdc->stream.tx);
-    tu_edpt_stream_deinit(&p_cdc->stream.rx);
+    (void)tu_edpt_stream_deinit(&p_cdc->stream.tx);
+    (void)tu_edpt_stream_deinit(&p_cdc->stream.rx);
   }
   return true;
 }
@@ -674,11 +670,9 @@ void cdch_close(uint8_t daddr) {
     cdch_interface_t *p_cdc = &cdch_data[idx];
     if (p_cdc->daddr == daddr) {
       TU_LOG_CDC(p_cdc, "close");
+      tuh_cdc_umount_cb(idx); // invoke callback
 
-      // Invoke application callback
-      tuh_cdc_umount_cb(idx);
-
-      p_cdc->daddr = 0;
+      p_cdc->daddr            = 0;
       p_cdc->bInterfaceNumber = 0;
       p_cdc->mounted = false;
       tu_edpt_stream_close(&p_cdc->stream.tx);
@@ -696,13 +690,12 @@ bool cdch_xfer_cb(uint8_t daddr, uint8_t ep_addr, xfer_result_t event, uint32_t
   TU_ASSERT(p_cdc);
 
   if (ep_addr == p_cdc->stream.tx.ep_addr) {
-    // invoke tx complete callback to possibly refill tx fifo
-    tuh_cdc_tx_complete_cb(idx);
+    tuh_cdc_tx_complete_cb(idx); // invoke transmit complete callback
 
     if (0 == tu_edpt_stream_write_xfer(daddr, &p_cdc->stream.tx)) {
       // If there is no data left, a ZLP should be sent if:
       // - xferred_bytes is multiple of EP Packet size and not zero
-      tu_edpt_stream_write_zlp_if_needed(daddr, &p_cdc->stream.tx, xferred_bytes);
+      (void)tu_edpt_stream_write_zlp_if_needed(daddr, &p_cdc->stream.tx, xferred_bytes);
     }
   } else if (ep_addr == p_cdc->stream.rx.ep_addr) {
     #if CFG_TUH_CDC_FTDI
@@ -718,7 +711,6 @@ bool cdch_xfer_cb(uint8_t daddr, uint8_t ep_addr, xfer_result_t event, uint32_t
     #endif
     {
       tu_edpt_stream_read_xfer_complete(&p_cdc->stream.rx, xferred_bytes);
-
       tuh_cdc_rx_cb(idx); // invoke receive callback
     }
 
@@ -727,7 +719,7 @@ bool cdch_xfer_cb(uint8_t daddr, uint8_t ep_addr, xfer_result_t event, uint32_t
   } else if (ep_addr == p_cdc->ep_notif) {
     // TODO handle notification endpoint
   } else {
-    TU_ASSERT(false);
+    return false;
   }
 
   return true;
@@ -736,20 +728,17 @@ bool cdch_xfer_cb(uint8_t daddr, uint8_t ep_addr, xfer_result_t event, uint32_t
 //--------------------------------------------------------------------+
 // Enumeration
 //--------------------------------------------------------------------+
-
 static bool open_ep_stream_pair(cdch_interface_t *p_cdc, tusb_desc_endpoint_t const *desc_ep) {
   for (size_t i = 0; i < 2; i++) {
     TU_ASSERT(TUSB_DESC_ENDPOINT == desc_ep->bDescriptorType &&
               TUSB_XFER_BULK == desc_ep->bmAttributes.xfer);
     TU_ASSERT(tuh_edpt_open(p_cdc->daddr, desc_ep));
+    tu_edpt_stream_t *stream =
+      (tu_edpt_dir(desc_ep->bEndpointAddress) == TUSB_DIR_IN) ? &p_cdc->stream.rx : &p_cdc->stream.tx;
+    tu_edpt_stream_open(stream, desc_ep);
+    tu_edpt_stream_clear(stream);
 
-    if (tu_edpt_dir(desc_ep->bEndpointAddress) == TUSB_DIR_IN) {
-      tu_edpt_stream_open(&p_cdc->stream.rx, desc_ep);
-    } else {
-      tu_edpt_stream_open(&p_cdc->stream.tx, desc_ep);
-    }
-
-    desc_ep = (tusb_desc_endpoint_t const *) tu_desc_next(desc_ep);
+    desc_ep = (const tusb_desc_endpoint_t *)tu_desc_next(desc_ep);
   }
 
   return true;
@@ -777,6 +766,8 @@ bool cdch_open(uint8_t rhport, uint8_t daddr, tusb_desc_interface_t const *itf_d
         }
       }
     }
+  } else {
+    // not supported class
   }
 
   return false;
@@ -830,6 +821,7 @@ static void cdch_process_set_config(tuh_xfer_t *xfer) {
   }
 }
 
+// return false if there is no active transfer
 static bool set_line_state_on_enum(cdch_interface_t *p_cdc, tuh_xfer_t *xfer) {
   enum {
     ENUM_SET_LINE_CODING = 0,
@@ -894,7 +886,7 @@ static void cdch_internal_control_complete(tuh_xfer_t *xfer) {
 
   // Invoke application callback
   xfer->complete_cb = p_cdc->user_complete_cb;
-  if (xfer->complete_cb) {
+  if (xfer->complete_cb != NULL) {
     xfer->complete_cb(xfer);
   }
 }
@@ -910,7 +902,7 @@ static void cdch_set_line_coding_stage1_baudrate_complete(tuh_xfer_t *xfer) {
     TU_ASSERT(driver->set_data_format(p_cdc, cdch_set_line_coding_stage2_data_format_complete, xfer->user_data),);
   } else {
     xfer->complete_cb = p_cdc->user_complete_cb;
-    if (xfer->complete_cb) {
+    if (xfer->complete_cb != NULL) {
       xfer->complete_cb(xfer);
     }
   }
@@ -926,7 +918,7 @@ static void cdch_set_line_coding_stage2_data_format_complete(tuh_xfer_t *xfer) {
   }
 
   xfer->complete_cb = p_cdc->user_complete_cb;
-  if (xfer->complete_cb) {
+  if (xfer->complete_cb != NULL) {
     xfer->complete_cb(xfer);
   }
 }
@@ -950,12 +942,12 @@ static void acm_internal_control_complete(cdch_interface_t *p_cdc, tuh_xfer_t *x
       break;
 
     default:
-      break;
+      break; // unknown request
   }
 }
 
 static bool acm_set_control_line_state(cdch_interface_t *p_cdc, tuh_xfer_cb_t complete_cb, uintptr_t user_data) {
-  TU_VERIFY(p_cdc->acm.capability.support_line_request);
+  TU_VERIFY(p_cdc->acm.capability.support_line_request != 0);
 
   const tusb_control_request_t request = {
     .bmRequestType_bit = {
@@ -982,7 +974,7 @@ static bool acm_set_control_line_state(cdch_interface_t *p_cdc, tuh_xfer_cb_t co
 }
 
 static bool acm_set_line_coding(cdch_interface_t *p_cdc, tuh_xfer_cb_t complete_cb, uintptr_t user_data) {
-  TU_VERIFY(p_cdc->acm.capability.support_line_request);
+  TU_VERIFY(p_cdc->acm.capability.support_line_request != 0);
   TU_VERIFY((p_cdc->requested_line.coding.data_bits >= 5 && p_cdc->requested_line.coding.data_bits <= 8) ||
             p_cdc->requested_line.coding.data_bits == 16);
 
@@ -1136,7 +1128,6 @@ static inline bool ftdi_sio_reset(cdch_interface_t *p_cdc, tuh_xfer_cb_t complet
 
 // internal control complete to update state such as line state, line_coding
 static void ftdi_internal_control_complete(cdch_interface_t* p_cdc, tuh_xfer_t *xfer) {
-  TU_VERIFY(xfer->result == XFER_RESULT_SUCCESS,);
   const tusb_control_request_t * setup = xfer->setup;
   if (xfer->result == XFER_RESULT_SUCCESS) {
     if (setup->bRequest      == FTDI_SIO_SET_MODEM_CTRL_REQUEST &&
@@ -1168,10 +1159,10 @@ static bool ftdi_set_data_format(cdch_interface_t *p_cdc, tuh_xfer_cb_t complete
 
 static bool ftdi_set_baudrate(cdch_interface_t *p_cdc, tuh_xfer_cb_t complete_cb, uintptr_t user_data) {
   uint32_t index_value = ftdi_get_divisor(p_cdc);
-  TU_VERIFY(index_value);
+  TU_VERIFY(index_value != 0);
   uint16_t value = (uint16_t) index_value;
   uint16_t index = (uint16_t) (index_value >> 16);
-  if (p_cdc->ftdi.channel) {
+  if (p_cdc->ftdi.channel != 0) {
     index = (uint16_t) ((index << 8) | p_cdc->ftdi.channel);
   }
 
@@ -1365,7 +1356,7 @@ static uint32_t ftdi_232bm_baud_base_to_divisor(uint32_t baud, uint32_t base) {
   uint8_t divfrac[8] = {0, 3, 2, 4, 1, 5, 6, 7};
   uint32_t divisor;
   /* divisor shifted 3 bits to the left */
-  uint32_t divisor3 = DIV_ROUND_CLOSEST(base, 2 * baud);
+  uint32_t divisor3 = tu_div_round_nearest(base, 2 * baud);
   divisor = divisor3 >> 3;
   divisor |= (uint32_t) divfrac[divisor3 & 0x7] << 14;
   /* Deal with special cases for highest baud rates. */
@@ -1373,6 +1364,8 @@ static uint32_t ftdi_232bm_baud_base_to_divisor(uint32_t baud, uint32_t base) {
     divisor = 0;
   } else if (divisor == 0x4001) /* 1.5 */ {
     divisor = 1;
+  } else {
+    // nothing to do
   }
   return divisor;
 }
@@ -1387,7 +1380,7 @@ static uint32_t ftdi_2232h_baud_base_to_divisor(uint32_t baud, uint32_t base) {
   uint32_t divisor3;
 
   /* hi-speed baud rate is 10-bit sampling instead of 16-bit */
-  divisor3 = DIV_ROUND_CLOSEST(8 * base, 10 * baud);
+  divisor3 = tu_div_round_nearest(8 * base, 10 * baud);
 
   divisor = divisor3 >> 3;
   divisor |= (uint32_t) divfrac[divisor3 & 0x7] << 14;
@@ -1396,12 +1389,13 @@ static uint32_t ftdi_2232h_baud_base_to_divisor(uint32_t baud, uint32_t base) {
     divisor = 0;
   } else if (divisor == 0x4001) /* 1.5 */ {
     divisor = 1;
+  } else {
+    // nothing to do
   }
-  /*
-   * Set this bit to turn off a divide by 2.5 on baud rate generator
+
+  /* Set this bit to turn off a divide by 2.5 on baud rate generator
    * This enables baud rates up to 12Mbaud but cannot reach below 1200
-   * baud with this bit set
-   */
+   * baud with this bit set */
   divisor |= 0x00020000;
   return divisor;
 }
@@ -1413,7 +1407,7 @@ static inline uint32_t ftdi_2232h_baud_to_divisor(uint32_t baud) {
 static inline uint32_t ftdi_get_divisor(cdch_interface_t *p_cdc) {
   uint32_t baud = p_cdc->requested_line.coding.bit_rate;
   uint32_t div_value = 0;
-  TU_VERIFY(baud);
+  TU_VERIFY(baud != 0);
 
   switch (p_cdc->ftdi.chip_type) {
     case FTDI_UNKNOWN:
@@ -1553,7 +1547,8 @@ static void cp210x_internal_control_complete(cdch_interface_t *p_cdc, tuh_xfer_t
       p_cdc->line.coding.bit_rate = p_cdc->requested_line.coding.bit_rate;
       break;
 
-    default: break;
+    default:
+      break; // unsupported request
   }
 }
 
@@ -1714,7 +1709,8 @@ static void ch34x_internal_control_complete(cdch_interface_t *p_cdc, tuh_xfer_t
           p_cdc->line.coding.data_bits = p_cdc->requested_line.coding.data_bits;
           break;
 
-        default: break;
+        default:
+          break; // unsupported
       }
       break;
 
@@ -1722,19 +1718,20 @@ static void ch34x_internal_control_complete(cdch_interface_t *p_cdc, tuh_xfer_t
       p_cdc->line.control_state = p_cdc->requested_line.control_state;
       break;
 
-    default: break;
+    default:
+      break; // unsupported request
   }
 }
 
 static bool ch34x_set_data_format(cdch_interface_t *p_cdc, tuh_xfer_cb_t complete_cb, uintptr_t user_data) {
   const uint8_t lcr = ch34x_get_lcr(p_cdc);
-  TU_VERIFY(lcr);
+  TU_VERIFY(lcr > 0);
   return ch34x_write_reg(p_cdc, CH32X_REG16_LCR2_LCR, lcr, complete_cb, user_data);
 }
 
 static bool ch34x_set_baudrate(cdch_interface_t *p_cdc, tuh_xfer_cb_t complete_cb, uintptr_t user_data) {
   const uint16_t div_ps = ch34x_get_divisor_prescaler(p_cdc);
-  TU_VERIFY(div_ps);
+  TU_VERIFY(div_ps > 0);
   return ch34x_write_reg(p_cdc, CH34X_REG16_DIVISOR_PRESCALER, div_ps, complete_cb, user_data);
 }
 
@@ -1917,7 +1914,8 @@ static uint8_t ch34x_get_lcr(cdch_interface_t *p_cdc) {
       lcr |= CH34X_LCR_ENABLE_PAR | CH34X_LCR_MARK_SPACE | CH34X_LCR_PAR_EVEN;
       break;
 
-    default: break;
+    default:
+      break; // invalid parity
   }
 
   // 1.5 stop bits not supported
@@ -2000,13 +1998,15 @@ static inline bool pl2303_supports_hx_status(cdch_interface_t *p_cdc, tuh_xfer_c
 //  return pl2303_set_request(p_cdc, PL2303_BREAK_REQUEST, PL2303_BREAK_REQUEST_TYPE, state, 0, NULL, 0);
 //}
 
-static inline int pl2303_clear_halt(cdch_interface_t *p_cdc, uint8_t endp, tuh_xfer_cb_t complete_cb, uintptr_t user_data) {
+static inline bool
+pl2303_clear_halt(cdch_interface_t *p_cdc, uint8_t endp, tuh_xfer_cb_t complete_cb, uintptr_t user_data) {
   /* we don't care if it wasn't halted first. in fact some devices
    * (like some ibmcam model 1 units) seem to expect hosts to make
    * this request for iso endpoints, which can't halt!
    */
-  return pl2303_set_request(p_cdc, TUSB_REQ_CLEAR_FEATURE, PL2303_CLEAR_HALT_REQUEST_TYPE, TUSB_REQ_FEATURE_EDPT_HALT, endp,
-                            NULL, 0, complete_cb, user_data);
+  return pl2303_set_request(
+      p_cdc, TUSB_REQ_CLEAR_FEATURE, PL2303_CLEAR_HALT_REQUEST_TYPE, TUSB_REQ_FEATURE_EDPT_HALT, endp, NULL, 0,
+      complete_cb, user_data);
 }
 
 //------------- Driver API -------------//
@@ -2131,10 +2131,9 @@ static bool pl2303_process_set_config(cdch_interface_t *p_cdc, tuh_xfer_t *xfer)
       if (type == PL2303_TYPE_NEED_SUPPORTS_HX_STATUS) {
         TU_ASSERT(pl2303_supports_hx_status(p_cdc, cdch_process_set_config, CONFIG_PL2303_READ1));
         break;
-      } else {
-        // no transfer triggered and continue with CONFIG_PL2303_READ1
-        TU_ATTR_FALLTHROUGH;
       }
+      // no transfer triggered and continue with CONFIG_PL2303_READ1
+      TU_ATTR_FALLTHROUGH;
 
     case CONFIG_PL2303_READ1:
       // get supports_hx_status, type and quirks (step 2), do special read
@@ -2379,10 +2378,12 @@ static pl2303_type_t pl2303_detect_type(cdch_interface_t *p_cdc, uint8_t step) {
           return PL2303_TYPE_HXN;
 
         default:
-          break;
+          break; // unknown device
       }
       break;
-    default: break;
+
+    default:
+      break; // unknown device
   }
 
   TU_LOG_CDC(p_cdc, "unknown device type bcdUSB = 0x%04x", desc_dev.bcdUSB);
@@ -2444,8 +2445,9 @@ static uint32_t pl2303_encode_baud_rate_divisor(uint8_t buf[PL2303_LINE_CODING_B
    */
   baseline = 12000000 * 32;
   mantissa = baseline / baud;
-  if (mantissa == 0)
+  if (mantissa == 0) {
     mantissa = 1; /* Avoid dividing by zero if baud > 32 * 12M. */
+  }
   exponent = 0;
   while (mantissa >= 512) {
     if (exponent < 7) {
@@ -2517,7 +2519,7 @@ static bool pl2303_encode_baud_rate(cdch_interface_t *p_cdc, uint8_t buf[PL2303_
    * Use direct method for supported baud rates, otherwise use divisors.
    * Newer chip types do not support divisor encoding.
    */
-  if (type_data->no_divisors) {
+  if (type_data->no_divisors != 0) {
     baud_sup = baud;
   } else {
     baud_sup = pl2303_get_supported_baud_rate(baud);
@@ -2525,7 +2527,7 @@ static bool pl2303_encode_baud_rate(cdch_interface_t *p_cdc, uint8_t buf[PL2303_
 
   if (baud == baud_sup) {
     baud = pl2303_encode_baud_rate_direct(buf, baud);
-  } else if (type_data->alt_divisors) {
+  } else if (type_data->alt_divisors != 0) {
     baud = pl2303_encode_baud_rate_divisor_alt(buf, baud);
   } else {
     baud = pl2303_encode_baud_rate_divisor(buf, baud);
diff --git a/src/class/cdc/cdc_host.h b/src/class/cdc/cdc_host.h
index bf6711d7e..e8637beac 100644
--- a/src/class/cdc/cdc_host.h
+++ b/src/class/cdc/cdc_host.h
@@ -24,8 +24,8 @@
  * This file is part of the TinyUSB stack.
  */
 
-#ifndef _TUSB_CDC_HOST_H_
-#define _TUSB_CDC_HOST_H_
+#ifndef TUSB_CDC_HOST_H_
+#define TUSB_CDC_HOST_H_
 
 #include "cdc.h"
 
@@ -255,4 +255,4 @@ void cdch_close      (uint8_t dev_addr);
  }
 #endif
 
-#endif /* _TUSB_CDC_HOST_H_ */
+#endif /* TUSB_CDC_HOST_H_ */
diff --git a/src/class/cdc/cdc_rndis.h b/src/class/cdc/cdc_rndis.h
index ad153e0ac..fbbd43206 100644
--- a/src/class/cdc/cdc_rndis.h
+++ b/src/class/cdc/cdc_rndis.h
@@ -30,8 +30,8 @@
  *  \defgroup CDC_RNDIS_Common Common Definitions
  *  @{ */
 
-#ifndef _TUSB_CDC_RNDIS_H_
-#define _TUSB_CDC_RNDIS_H_
+#ifndef TUSB_CDC_RNDIS_H_
+#define TUSB_CDC_RNDIS_H_
 
 #include "cdc.h"
 
@@ -295,7 +295,7 @@ typedef enum
  }
 #endif
 
-#endif /* _TUSB_CDC_RNDIS_H_ */
+#endif /* TUSB_CDC_RNDIS_H_ */
 
 /** @} */
 /** @} */
diff --git a/src/class/cdc/cdc_rndis_host.h b/src/class/cdc/cdc_rndis_host.h
index bb431ec1f..e70d27f79 100644
--- a/src/class/cdc/cdc_rndis_host.h
+++ b/src/class/cdc/cdc_rndis_host.h
@@ -28,8 +28,8 @@
  * \defgroup CDC_RNSID_Host Host
  *  @{ */
 
-#ifndef _TUSB_CDC_RNDIS_HOST_H_
-#define _TUSB_CDC_RNDIS_HOST_H_
+#ifndef TUSB_CDC_RNDIS_HOST_H_
+#define TUSB_CDC_RNDIS_HOST_H_
 
 #include "common/tusb_common.h"
 #include "host/usbh.h"
@@ -58,6 +58,6 @@ void rndish_close(uint8_t dev_addr);
  }
 #endif
 
-#endif /* _TUSB_CDC_RNDIS_HOST_H_ */
+#endif /* TUSB_CDC_RNDIS_HOST_H_ */
 
 /** @} */
diff --git a/src/class/cdc/serial/ftdi_sio.h b/src/class/cdc/serial/ftdi_sio.h
index 8abf74f11..9bd56cef4 100644
--- a/src/class/cdc/serial/ftdi_sio.h
+++ b/src/class/cdc/serial/ftdi_sio.h
@@ -215,17 +215,4 @@ typedef struct ftdi_private {
 #define FTDI_NOT_POSSIBLE -1
 #define FTDI_REQUESTED    -2
 
-// division and round function overtaken from math.h
-#define DIV_ROUND_CLOSEST(x, divisor)(      \
-{             \
-  typeof(x) __x = x;        \
-  typeof(divisor) __d = divisor;      \
-  (((typeof(x))-1) > 0 ||       \
-   ((typeof(divisor))-1) > 0 ||     \
-   (((__x) > 0) == ((__d) > 0))) ?    \
-    (((__x) + ((__d) / 2)) / (__d)) : \
-    (((__x) - ((__d) / 2)) / (__d));  \
-}             \
-)
-
 #endif //TUSB_FTDI_SIO_H
diff --git a/src/class/dfu/dfu.h b/src/class/dfu/dfu.h
index 114c827b8..8cd63656a 100644
--- a/src/class/dfu/dfu.h
+++ b/src/class/dfu/dfu.h
@@ -24,8 +24,8 @@
  * This file is part of the TinyUSB stack.
  */
 
-#ifndef _TUSB_DFU_H_
-#define _TUSB_DFU_H_
+#ifndef TUSB_DFU_H_
+#define TUSB_DFU_H_
 
 #include "common/tusb_common.h"
 
@@ -116,4 +116,4 @@ TU_VERIFY_STATIC( sizeof(dfu_status_response_t) == 6, "size is not correct");
  }
 #endif
 
-#endif /* _TUSB_DFU_H_ */
+#endif /* TUSB_DFU_H_ */
diff --git a/src/class/dfu/dfu_device.c b/src/class/dfu/dfu_device.c
index 0d2b63b57..d3cc53918 100644
--- a/src/class/dfu/dfu_device.c
+++ b/src/class/dfu/dfu_device.c
@@ -50,21 +50,17 @@
 typedef struct {
   uint8_t attrs;
   uint8_t alt;
+  uint8_t state;
+  uint8_t status;
 
-  dfu_state_t state;
-  dfu_status_t status;
-
-  bool flashing_in_progress;
+  bool     flashing_in_progress;
   uint16_t block;
   uint16_t length;
 } dfu_state_ctx_t;
 
-// Only a single dfu state is allowed
 static dfu_state_ctx_t _dfu_ctx;
 
-CFG_TUD_MEM_SECTION static struct {
-  TUD_EPBUF_DEF(transfer_buf, CFG_TUD_DFU_XFER_BUFSIZE);
-} _dfu_epbuf;
+TU_ATTR_ALIGNED(4) uint8_t _transfer_buf[CFG_TUD_DFU_XFER_BUFSIZE];
 
 static void reset_state(void) {
   _dfu_ctx.state = DFU_IDLE;
@@ -253,6 +249,8 @@ bool dfu_moded_control_xfer_cb(uint8_t rhport, uint8_t stage, const tusb_control
           tud_control_status(rhport, request);
         } else if (stage == CONTROL_STAGE_ACK) {
           tud_dfu_detach_cb();
+        } else {
+          // nothing to do
         }
         break;
 
@@ -275,6 +273,8 @@ bool dfu_moded_control_xfer_cb(uint8_t rhport, uint8_t stage, const tusb_control
           tud_control_status(rhport, request);
         } else if (stage == CONTROL_STAGE_ACK) {
           tud_dfu_abort_cb(_dfu_ctx.alt);
+        } else {
+          // nothing to do
         }
         break;
 
@@ -283,10 +283,10 @@ bool dfu_moded_control_xfer_cb(uint8_t rhport, uint8_t stage, const tusb_control
           TU_VERIFY(_dfu_ctx.attrs & DFU_ATTR_CAN_UPLOAD);
           TU_VERIFY(request->wLength <= CFG_TUD_DFU_XFER_BUFSIZE);
 
-          const uint16_t xfer_len = tud_dfu_upload_cb(_dfu_ctx.alt, request->wValue, _dfu_epbuf.transfer_buf,
+          const uint16_t xfer_len = tud_dfu_upload_cb(_dfu_ctx.alt, request->wValue, _transfer_buf,
                                                       request->wLength);
 
-          return tud_control_xfer(rhport, request, _dfu_epbuf.transfer_buf, xfer_len);
+          return tud_control_xfer(rhport, request, _transfer_buf, xfer_len);
         }
         break;
 
@@ -303,10 +303,10 @@ bool dfu_moded_control_xfer_cb(uint8_t rhport, uint8_t stage, const tusb_control
           _dfu_ctx.block = request->wValue;
           _dfu_ctx.length = request->wLength;
 
-          if (request->wLength) {
+          if (request->wLength > 0) {
             // Download with payload -> transition to DOWNLOAD SYNC
             _dfu_ctx.state = DFU_DNLOAD_SYNC;
-            return tud_control_xfer(rhport, request, _dfu_epbuf.transfer_buf, request->wLength);
+            return tud_control_xfer(rhport, request, _transfer_buf, request->wLength);
           } else {
             // Download is complete -> transition to MANIFEST SYNC
             _dfu_ctx.state = DFU_MANIFEST_SYNC;
@@ -352,6 +352,8 @@ void tud_dfu_finish_flashing(uint8_t status) {
       _dfu_ctx.state = (_dfu_ctx.attrs & DFU_ATTR_MANIFESTATION_TOLERANT)
                          ? DFU_MANIFEST_SYNC
                          : DFU_MANIFEST_WAIT_RESET;
+    } else {
+      // nothing to do
     }
   } else {
     // failed while flashing, move to dfuError
@@ -378,10 +380,12 @@ static bool process_download_get_status(uint8_t rhport, uint8_t stage, const tus
   } else if (stage == CONTROL_STAGE_ACK) {
     if (_dfu_ctx.flashing_in_progress) {
       _dfu_ctx.state = DFU_DNBUSY;
-      tud_dfu_download_cb(_dfu_ctx.alt, _dfu_ctx.block, _dfu_epbuf.transfer_buf, _dfu_ctx.length);
+      tud_dfu_download_cb(_dfu_ctx.alt, _dfu_ctx.block, _transfer_buf, _dfu_ctx.length);
     } else {
       _dfu_ctx.state = DFU_DNLOAD_IDLE;
     }
+  } else {
+    // nothing to do
   }
 
   return true;
@@ -409,6 +413,8 @@ static bool process_manifest_get_status(uint8_t rhport, uint8_t stage, const tus
     } else {
       _dfu_ctx.state = DFU_IDLE;
     }
+  } else {
+    // nothing to do
   }
 
   return true;
diff --git a/src/class/dfu/dfu_device.h b/src/class/dfu/dfu_device.h
index e59e61ce9..b22b4c450 100644
--- a/src/class/dfu/dfu_device.h
+++ b/src/class/dfu/dfu_device.h
@@ -24,8 +24,8 @@
  * This file is part of the TinyUSB stack.
  */
 
-#ifndef _TUSB_DFU_DEVICE_H_
-#define _TUSB_DFU_DEVICE_H_
+#ifndef TUSB_DFU_DEVICE_H_
+#define TUSB_DFU_DEVICE_H_
 
 #include "dfu.h"
 
@@ -96,4 +96,4 @@ bool     dfu_moded_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb_control_r
  }
 #endif
 
-#endif /* _TUSB_DFU_MODE_DEVICE_H_ */
+#endif /* TUSB_DFU_MODE_DEVICE_H_ */
diff --git a/src/class/dfu/dfu_rt_device.h b/src/class/dfu/dfu_rt_device.h
index 67eb26d95..c4116d8fe 100644
--- a/src/class/dfu/dfu_rt_device.h
+++ b/src/class/dfu/dfu_rt_device.h
@@ -24,8 +24,8 @@
  * This file is part of the TinyUSB stack.
  */
 
-#ifndef _TUSB_DFU_RT_DEVICE_H_
-#define _TUSB_DFU_RT_DEVICE_H_
+#ifndef TUSB_DFU_RT_DEVICE_H_
+#define TUSB_DFU_RT_DEVICE_H_
 
 #include "dfu.h"
 
@@ -52,4 +52,4 @@ bool     dfu_rtd_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb_control_req
  }
 #endif
 
-#endif /* _TUSB_DFU_RT_DEVICE_H_ */
+#endif /* TUSB_DFU_RT_DEVICE_H_ */
diff --git a/src/class/hid/hid.h b/src/class/hid/hid.h
index b69f623a0..0883d95ac 100644
--- a/src/class/hid/hid.h
+++ b/src/class/hid/hid.h
@@ -28,8 +28,8 @@
  *  \defgroup ClassDriver_HID Human Interface Device (HID)
  *  @{ */
 
-#ifndef _TUSB_HID_H_
-#define _TUSB_HID_H_
+#ifndef TUSB_HID_H_
+#define TUSB_HID_H_
 
 #include "common/tusb_common.h"
 
@@ -2071,6 +2071,6 @@ enum {
  }
 #endif
 
-#endif /* _TUSB_HID_H__ */
+#endif /* TUSB_HID_H__ */
 
 /// @}
diff --git a/src/class/hid/hid_device.c b/src/class/hid/hid_device.c
index b4f24902b..6ee4cd9c1 100644
--- a/src/class/hid/hid_device.c
+++ b/src/class/hid/hid_device.c
@@ -128,7 +128,7 @@ bool tud_hid_n_report(uint8_t instance, uint8_t report_id, void const *report, u
     TU_VERIFY(0 == tu_memcpy_s(p_epbuf->epin, CFG_TUD_HID_EP_BUFSIZE, report, len));
   }
 
-  return usbd_edpt_xfer(rhport, p_hid->ep_in, p_epbuf->epin, len);
+  return usbd_edpt_xfer(rhport, p_hid->ep_in, p_epbuf->epin, len, false);
 }
 
 uint8_t tud_hid_n_interface_protocol(uint8_t instance) {
@@ -263,7 +263,7 @@ uint16_t hidd_open(uint8_t rhport, tusb_desc_interface_t const *desc_itf, uint16
 
   // Prepare for output endpoint
   if (p_hid->ep_out) {
-    TU_ASSERT(usbd_edpt_xfer(rhport, p_hid->ep_out, p_epbuf->epout, CFG_TUD_HID_EP_BUFSIZE), drv_len);
+    TU_ASSERT(usbd_edpt_xfer(rhport, p_hid->ep_out, p_epbuf->epout, CFG_TUD_HID_EP_BUFSIZE, false), drv_len);
   }
 
   return drv_len;
@@ -413,7 +413,7 @@ bool hidd_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint32_
     }
 
     // prepare for new transfer
-    TU_ASSERT(usbd_edpt_xfer(rhport, p_hid->ep_out, p_epbuf->epout, CFG_TUD_HID_EP_BUFSIZE));
+    TU_ASSERT(usbd_edpt_xfer(rhport, p_hid->ep_out, p_epbuf->epout, CFG_TUD_HID_EP_BUFSIZE, false));
   }
 
   return true;
diff --git a/src/class/hid/hid_device.h b/src/class/hid/hid_device.h
index fc1dbcbd8..32b572973 100644
--- a/src/class/hid/hid_device.h
+++ b/src/class/hid/hid_device.h
@@ -267,14 +267,14 @@ void tud_hid_report_failed_cb(uint8_t instance, hid_report_type_t report_type, u
 // Stylus Pen Report Descriptor Template
 #define TUD_HID_REPORT_DESC_STYLUS_PEN(...) \
   HID_USAGE_PAGE ( HID_USAGE_PAGE_DIGITIZER )                     , \
-  HID_USAGE      ( HID_USAGE_DIGITIZER_TOUCH_SCREEN )             , \
+  HID_USAGE      ( HID_USAGE_DIGITIZER_PEN )                      , \
   HID_COLLECTION ( HID_COLLECTION_APPLICATION  )                  , \
     /* Report ID if any */\
     __VA_ARGS__ \
-    HID_USAGE    ( HID_USAGE_DIGITIZER_STYLUS )                   , \
-    HID_COLLECTION ( HID_COLLECTION_PHYSICAL   )                  , \
-      HID_USAGE_PAGE  ( HID_USAGE_DIGITIZER_TIP_SWITCH )          , \
-      HID_USAGE_PAGE  ( HID_USAGE_DIGITIZER_IN_RANGE )            , \
+    HID_USAGE    ( HID_USAGE_DIGITIZER_STYLUS                    ), \
+    HID_COLLECTION ( HID_COLLECTION_PHYSICAL                     ), \
+        HID_USAGE  ( HID_USAGE_DIGITIZER_TIP_SWITCH              ), \
+        HID_USAGE  ( HID_USAGE_DIGITIZER_IN_RANGE                ), \
         HID_LOGICAL_MIN ( 0                                      ), \
         HID_LOGICAL_MAX ( 1                                      ), \
         HID_REPORT_SIZE ( 1                                      ), \
diff --git a/src/class/hid/hid_host.h b/src/class/hid/hid_host.h
index 032827af1..87f0e7dc9 100644
--- a/src/class/hid/hid_host.h
+++ b/src/class/hid/hid_host.h
@@ -24,8 +24,8 @@
  * This file is part of the TinyUSB stack.
  */
 
-#ifndef _TUSB_HID_HOST_H_
-#define _TUSB_HID_HOST_H_
+#ifndef TUSB_HID_HOST_H_
+#define TUSB_HID_HOST_H_
 
 #include "hid.h"
 
@@ -182,4 +182,4 @@ void hidh_close(uint8_t dev_addr);
 }
 #endif
 
-#endif /* _TUSB_HID_HOST_H_ */
+#endif /* TUSB_HID_HOST_H_ */
diff --git a/src/class/midi/midi_device.c b/src/class/midi/midi_device.c
index 7dac7c4a5..b20903d68 100644
--- a/src/class/midi/midi_device.c
+++ b/src/class/midi/midi_device.c
@@ -37,12 +37,18 @@
 #include "midi_device.h"
 
 //--------------------------------------------------------------------+
+// Weak stubs: invoked if no strong implementation is available
+//--------------------------------------------------------------------+
+TU_ATTR_WEAK void tud_midi_rx_cb(uint8_t itf) {
+  (void)itf;
+}
+
+//--------------------------------------------------------------------+
 // MACRO CONSTANT TYPEDEF
 //--------------------------------------------------------------------+
 typedef struct {
+  uint8_t rhport;
   uint8_t itf_num;
-  uint8_t ep_in;
-  uint8_t ep_out;
 
   // For Stream read()/write() API
   // Messages are always 4 bytes long, queue them for reading and writing so the
@@ -51,134 +57,97 @@ typedef struct {
   midi_driver_stream_t stream_read;
 
   /*------------- From this point, data is not cleared by bus reset -------------*/
-  // FIFO
-  tu_fifo_t rx_ff;
-  tu_fifo_t tx_ff;
-  uint8_t rx_ff_buf[CFG_TUD_MIDI_RX_BUFSIZE];
-  uint8_t tx_ff_buf[CFG_TUD_MIDI_TX_BUFSIZE];
+  // Endpoint stream
+  struct {
+    tu_edpt_stream_t tx;
+    tu_edpt_stream_t rx;
 
-  #if CFG_FIFO_MUTEX
-  osal_mutex_def_t rx_ff_mutex;
-  osal_mutex_def_t tx_ff_mutex;
-  #endif
+    uint8_t rx_ff_buf[CFG_TUD_MIDI_RX_BUFSIZE];
+    uint8_t tx_ff_buf[CFG_TUD_MIDI_TX_BUFSIZE];
+  } ep_stream;
 } midid_interface_t;
 
-#define ITF_MEM_RESET_SIZE   offsetof(midid_interface_t, rx_ff)
+#define ITF_MEM_RESET_SIZE offsetof(midid_interface_t, ep_stream)
+
+static midid_interface_t _midid_itf[CFG_TUD_MIDI];
 
 // Endpoint Transfer buffer
-CFG_TUD_MEM_SECTION static struct {
+typedef struct {
   TUD_EPBUF_DEF(epin, CFG_TUD_MIDI_EP_BUFSIZE);
   TUD_EPBUF_DEF(epout, CFG_TUD_MIDI_EP_BUFSIZE);
-} _midid_epbuf[CFG_TUD_MIDI];
+} midid_epbuf_t;
+
+CFG_TUD_MEM_SECTION static midid_epbuf_t _midid_epbuf[CFG_TUD_MIDI];
 
 //--------------------------------------------------------------------+
 // INTERNAL OBJECT & FUNCTION DECLARATION
 //--------------------------------------------------------------------+
-static midid_interface_t _midid_itf[CFG_TUD_MIDI];
-
 bool tud_midi_n_mounted (uint8_t itf) {
-  midid_interface_t* midi = &_midid_itf[itf];
-  return midi->ep_in && midi->ep_out;
-}
-
-static void _prep_out_transaction(uint8_t idx) {
-  const uint8_t rhport = 0;
-  midid_interface_t* p_midi = &_midid_itf[idx];
-  uint16_t available = tu_fifo_remaining(&p_midi->rx_ff);
-
-  // Prepare for incoming data but only allow what we can store in the ring buffer.
-  // TODO Actually we can still carry out the transfer, keeping count of received bytes
-  // and slowly move it to the FIFO when read().
-  // This pre-check reduces endpoint claiming
-  TU_VERIFY(available >= CFG_TUD_MIDI_EP_BUFSIZE, );
-
-  // claim endpoint
-  TU_VERIFY(usbd_edpt_claim(rhport, p_midi->ep_out), );
-
-  // fifo can be changed before endpoint is claimed
-  available = tu_fifo_remaining(&p_midi->rx_ff);
-
-  if ( available >= CFG_TUD_MIDI_EP_BUFSIZE )  {
-    usbd_edpt_xfer(rhport, p_midi->ep_out, _midid_epbuf[idx].epout, CFG_TUD_MIDI_EP_BUFSIZE);
-  }else
-  {
-    // Release endpoint since we don't make any transfer
-    usbd_edpt_release(rhport, p_midi->ep_out);
-  }
-}
-
+  midid_interface_t *p_midi = &_midid_itf[itf];
 
-//--------------------------------------------------------------------+
-// Weak stubs: invoked if no strong implementation is available
-//--------------------------------------------------------------------+
-TU_ATTR_WEAK void tud_midi_rx_cb(uint8_t itf) {
-  (void) itf;
+  const bool tx_opened = tu_edpt_stream_is_opened(&p_midi->ep_stream.tx);
+  const bool rx_opened = tu_edpt_stream_is_opened(&p_midi->ep_stream.rx);
+  return tx_opened && rx_opened;
 }
 
 //--------------------------------------------------------------------+
 // READ API
 //--------------------------------------------------------------------+
-uint32_t tud_midi_n_available(uint8_t itf, uint8_t cable_num)
-{
+uint32_t tud_midi_n_available(uint8_t itf, uint8_t cable_num) {
   (void) cable_num;
-
-  midid_interface_t* midi = &_midid_itf[itf];
-  const midi_driver_stream_t* stream = &midi->stream_read;
+  const midid_interface_t    *p_midi = &_midid_itf[itf];
+  const midi_driver_stream_t *stream = &p_midi->stream_read;
+  const tu_edpt_stream_t     *ep_str = &p_midi->ep_stream.rx;
 
   // when using with packet API stream total & index are both zero
-  return tu_fifo_count(&midi->rx_ff) + (uint8_t) (stream->total - stream->index);
+  return tu_edpt_stream_read_available(ep_str) + (uint8_t)(stream->total - stream->index);
 }
 
-uint32_t tud_midi_n_stream_read(uint8_t itf, uint8_t cable_num, void* buffer, uint32_t bufsize)
-{
+uint32_t tud_midi_n_stream_read(uint8_t itf, uint8_t cable_num, void *buffer, uint32_t bufsize) {
   (void) cable_num;
-  TU_VERIFY(bufsize, 0);
-
-  uint8_t* buf8 = (uint8_t*) buffer;
+  TU_VERIFY(buffer != NULL && bufsize > 0, 0);
 
-  midid_interface_t* midi = &_midid_itf[itf];
-  midi_driver_stream_t* stream = &midi->stream_read;
+  uint8_t              *buf8   = (uint8_t *)buffer;
+  midid_interface_t    *p_midi = &_midid_itf[itf];
+  midi_driver_stream_t *stream = &p_midi->stream_read;
 
   uint32_t total_read = 0;
-  while( bufsize )
-  {
+  while (bufsize > 0) {
     // Get new packet from fifo, then set packet expected bytes
-    if ( stream->total == 0 )
-    {
-      // return if there is no more data from fifo
-      if ( !tud_midi_n_packet_read(itf, stream->buffer) ) return total_read;
+    if (stream->total == 0) {
+      if (!tud_midi_n_packet_read(itf, stream->buffer)) {
+        return total_read; // return if there is no more data from fifo
+      }
 
-      uint8_t const code_index = stream->buffer[0] & 0x0f;
+      const uint8_t code_index = stream->buffer[0] & 0x0f;
 
       // MIDI 1.0 Table 4-1: Code Index Number Classifications
-      switch(code_index)
-      {
+      switch (code_index) {
         case MIDI_CIN_MISC:
         case MIDI_CIN_CABLE_EVENT:
           // These are reserved and unused, possibly issue somewhere, skip this packet
           return 0;
-        break;
 
         case MIDI_CIN_SYSEX_END_1BYTE:
         case MIDI_CIN_1BYTE_DATA:
           stream->total = 1;
-        break;
+          break;
 
         case MIDI_CIN_SYSCOM_2BYTE     :
         case MIDI_CIN_SYSEX_END_2BYTE  :
         case MIDI_CIN_PROGRAM_CHANGE   :
         case MIDI_CIN_CHANNEL_PRESSURE :
           stream->total = 2;
-        break;
+          break;
 
         default:
           stream->total = 3;
-        break;
+          break;
       }
     }
 
     // Copy data up to bufsize
-    uint8_t const count = (uint8_t) tu_min32(stream->total - stream->index, bufsize);
+    const uint8_t count = (uint8_t)tu_min32((uint32_t)(stream->total - stream->index), bufsize);
 
     // Skip the header (1st byte) in the buffer
     TU_VERIFY(0 == tu_memcpy_s(buf8, bufsize, stream->buffer + 1 + stream->index, count));
@@ -189,8 +158,7 @@ uint32_t tud_midi_n_stream_read(uint8_t itf, uint8_t cable_num, void* buffer, ui
     bufsize -= count;
 
     // complete current event packet, reset stream
-    if ( stream->total == stream->index )
-    {
+    if (stream->total == stream->index) {
       stream->index = 0;
       stream->total = 0;
     }
@@ -199,150 +167,107 @@ uint32_t tud_midi_n_stream_read(uint8_t itf, uint8_t cable_num, void* buffer, ui
   return total_read;
 }
 
-bool tud_midi_n_packet_read (uint8_t itf, uint8_t packet[4])
-{
-  midid_interface_t* midi = &_midid_itf[itf];
-  TU_VERIFY(midi->ep_out);
+bool tud_midi_n_packet_read(uint8_t itf, uint8_t packet[4]) {
+  midid_interface_t *p_midi = &_midid_itf[itf];
+  tu_edpt_stream_t  *ep_str = &p_midi->ep_stream.rx;
+  TU_VERIFY(tu_edpt_stream_is_opened(ep_str));
+  return 4 == tu_edpt_stream_read(p_midi->rhport, ep_str, packet, 4);
+}
+
+uint32_t tud_midi_n_packet_read_n(uint8_t itf, uint8_t packets[], uint32_t max_packets) {
+  midid_interface_t *p_midi = &_midid_itf[itf];
+  tu_edpt_stream_t  *ep_str = &p_midi->ep_stream.rx;
+  TU_VERIFY(tu_edpt_stream_is_opened(ep_str), 0);
 
-  const uint32_t num_read = tu_fifo_read_n(&midi->rx_ff, packet, 4);
-  _prep_out_transaction(itf);
-  return (num_read == 4);
+  const uint32_t num_read = tu_edpt_stream_read(p_midi->rhport, ep_str, packets, 4u * max_packets);
+  return num_read >> 2u;
 }
 
 //--------------------------------------------------------------------+
 // WRITE API
 //--------------------------------------------------------------------+
-
-static uint32_t write_flush(uint8_t idx) {
-  midid_interface_t* midi = &_midid_itf[idx];
-
-  if (!tu_fifo_count(&midi->tx_ff)) {
-    return 0; // No data to send
-  }
-
-  const uint8_t rhport = 0;
-
-  // skip if previous transfer not complete
-  TU_VERIFY( usbd_edpt_claim(rhport, midi->ep_in), 0 );
-
-  uint16_t count = tu_fifo_read_n(&midi->tx_ff, _midid_epbuf[idx].epin, CFG_TUD_MIDI_EP_BUFSIZE);
-
-  if (count) {
-    TU_ASSERT( usbd_edpt_xfer(rhport, midi->ep_in, _midid_epbuf[idx].epin, count), 0 );
-    return count;
-  }else {
-    // Release endpoint since we don't make any transfer
-    usbd_edpt_release(rhport, midi->ep_in);
-    return 0;
-  }
-}
-
-uint32_t tud_midi_n_stream_write(uint8_t itf, uint8_t cable_num, const uint8_t* buffer, uint32_t bufsize)
-{
-  midid_interface_t* midi = &_midid_itf[itf];
-  TU_VERIFY(midi->ep_in, 0);
-
-  midi_driver_stream_t* stream = &midi->stream_write;
+uint32_t tud_midi_n_stream_write(uint8_t itf, uint8_t cable_num, const uint8_t *buffer, uint32_t bufsize) {
+  midid_interface_t *p_midi = &_midid_itf[itf];
+  midi_driver_stream_t *stream = &p_midi->stream_write;
+  tu_edpt_stream_t  *ep_str = &p_midi->ep_stream.tx;
+  TU_VERIFY(tu_edpt_stream_is_opened(ep_str), 0);
 
   uint32_t i = 0;
-  while ( (i < bufsize) && (tu_fifo_remaining(&midi->tx_ff) >= 4) )
-  {
+  while (i < bufsize) {
+    if (tu_edpt_stream_write_available(p_midi->rhport, ep_str) < 4) {
+      break;
+    }
+
     const uint8_t data = buffer[i];
     i++;
 
-    if ( stream->index == 0 )
-    {
+    if (stream->index == 0) {
       //------------- New event packet -------------//
       const uint8_t msg = data >> 4;
 
-      stream->index = 2;
+      stream->index     = 2;
       stream->buffer[1] = data;
 
       // Check to see if we're still in a SysEx transmit.
-      if ( ((stream->buffer[0]) & 0xF) == MIDI_CIN_SYSEX_START )
-      {
-        if ( data == MIDI_STATUS_SYSEX_END )
-        {
-          stream->buffer[0] = (uint8_t) ((cable_num << 4) | MIDI_CIN_SYSEX_END_1BYTE);
-          stream->total = 2;
-        }
-        else
-        {
+      if (((stream->buffer[0]) & 0xF) == MIDI_CIN_SYSEX_START) {
+        if (data == MIDI_STATUS_SYSEX_END) {
+          stream->buffer[0] = (uint8_t)((cable_num << 4) | MIDI_CIN_SYSEX_END_1BYTE);
+          stream->total     = 2;
+        } else {
           stream->total = 4;
         }
-      }
-      else if ( (msg >= 0x8 && msg <= 0xB) || msg == 0xE )
-      {
+      } else if ((msg >= 0x8 && msg <= 0xB) || msg == 0xE) {
         // Channel Voice Messages
-        stream->buffer[0] = (uint8_t) ((cable_num << 4) | msg);
-        stream->total = 4;
-      }
-      else if ( msg == 0xC || msg == 0xD)
-      {
+        stream->buffer[0] = (uint8_t)((cable_num << 4) | msg);
+        stream->total     = 4;
+      } else if (msg == 0xC || msg == 0xD) {
         // Channel Voice Messages, two-byte variants (Program Change and Channel Pressure)
-        stream->buffer[0] = (uint8_t) ((cable_num << 4) | msg);
-        stream->total = 3;
-      }
-      else if ( msg == 0xf )
-      {
+        stream->buffer[0] = (uint8_t)((cable_num << 4) | msg);
+        stream->total     = 3;
+      } else if (msg == 0xf) {
         // System message
-        if ( data == MIDI_STATUS_SYSEX_START )
-        {
+        if (data == MIDI_STATUS_SYSEX_START) {
           stream->buffer[0] = MIDI_CIN_SYSEX_START;
-          stream->total = 4;
-        }
-        else if ( data == MIDI_STATUS_SYSCOM_TIME_CODE_QUARTER_FRAME || data == MIDI_STATUS_SYSCOM_SONG_SELECT )
-        {
+          stream->total     = 4;
+        } else if (data == MIDI_STATUS_SYSCOM_TIME_CODE_QUARTER_FRAME || data == MIDI_STATUS_SYSCOM_SONG_SELECT) {
           stream->buffer[0] = MIDI_CIN_SYSCOM_2BYTE;
-          stream->total = 3;
-        }
-        else if ( data == MIDI_STATUS_SYSCOM_SONG_POSITION_POINTER )
-        {
+          stream->total     = 3;
+        } else if (data == MIDI_STATUS_SYSCOM_SONG_POSITION_POINTER) {
           stream->buffer[0] = MIDI_CIN_SYSCOM_3BYTE;
-          stream->total = 4;
-        }
-        else
-        {
+          stream->total     = 4;
+        } else {
           stream->buffer[0] = MIDI_CIN_SYSEX_END_1BYTE;
-          stream->total = 2;
+          stream->total     = 2;
         }
         stream->buffer[0] |= (uint8_t)(cable_num << 4);
-      }
-      else
-      {
+      } else {
         // Pack individual bytes if we don't support packing them into words.
-        stream->buffer[0] = (uint8_t) (cable_num << 4 | 0xf);
+        stream->buffer[0] = (uint8_t)(cable_num << 4 | 0xf);
         stream->buffer[2] = 0;
         stream->buffer[3] = 0;
-        stream->index = 2;
-        stream->total = 2;
+        stream->total     = 2; // index already set to 2
       }
-    }
-    else
-    {
+    } else {
       //------------- On-going (buffering) packet -------------//
-
       TU_ASSERT(stream->index < 4, i);
       stream->buffer[stream->index] = data;
       stream->index++;
 
       // See if this byte ends a SysEx.
-      if ( (stream->buffer[0] & 0xF) == MIDI_CIN_SYSEX_START && data == MIDI_STATUS_SYSEX_END )
-      {
-        stream->buffer[0] = (uint8_t) ((cable_num << 4) | (MIDI_CIN_SYSEX_START + (stream->index - 1)));
-        stream->total = stream->index;
+      if ((stream->buffer[0] & 0xF) == MIDI_CIN_SYSEX_START && data == MIDI_STATUS_SYSEX_END) {
+        stream->buffer[0] = (uint8_t)((cable_num << 4) | (MIDI_CIN_SYSEX_START + (stream->index - 1)));
+        stream->total     = stream->index;
       }
     }
 
     // Send out packet
-    if ( stream->index == stream->total )
-    {
+    if (stream->index == stream->total) {
       // zeroes unused bytes
       for (uint8_t idx = stream->total; idx < 4; idx++) {
         stream->buffer[idx] = 0;
       }
 
-      const uint16_t count = tu_fifo_write_n(&midi->tx_ff, stream->buffer, 4);
+      const uint32_t count = tu_edpt_stream_write(p_midi->rhport, ep_str, stream->buffer, 4);
 
       // complete current event packet, reset stream
       stream->index = stream->total = 0;
@@ -352,25 +277,37 @@ uint32_t tud_midi_n_stream_write(uint8_t itf, uint8_t cable_num, const uint8_t*
     }
   }
 
-  write_flush(itf);
+  (void)tu_edpt_stream_write_xfer(p_midi->rhport, ep_str);
 
   return i;
 }
 
 bool tud_midi_n_packet_write (uint8_t itf, const uint8_t packet[4]) {
-  midid_interface_t* midi = &_midid_itf[itf];
-  TU_VERIFY(midi->ep_in);
+  midid_interface_t *p_midi = &_midid_itf[itf];
+  tu_edpt_stream_t  *ep_str = &p_midi->ep_stream.tx;
+  TU_VERIFY(tu_edpt_stream_is_opened(ep_str));
 
-  if (tu_fifo_remaining(&midi->tx_ff) < 4) {
-    return false;
-  }
-
-  tu_fifo_write_n(&midi->tx_ff, packet, 4);
-  write_flush(itf);
+  TU_VERIFY(tu_edpt_stream_write_available(p_midi->rhport, ep_str) >= 4);
+  TU_VERIFY(tu_edpt_stream_write(p_midi->rhport, ep_str, packet, 4) > 0);
+  (void)tu_edpt_stream_write_xfer(p_midi->rhport, ep_str);
 
   return true;
 }
 
+uint32_t tud_midi_n_packet_write_n(uint8_t itf, const uint8_t packets[], uint32_t n_packets) {
+  midid_interface_t *p_midi = &_midid_itf[itf];
+  tu_edpt_stream_t  *ep_str = &p_midi->ep_stream.tx;
+  TU_VERIFY(tu_edpt_stream_is_opened(ep_str), 0);
+
+  uint32_t n_bytes = tu_edpt_stream_write_available(p_midi->rhport, ep_str);
+  n_bytes          = tu_min32(tu_align4(n_bytes), n_packets << 2u);
+
+  const uint32_t n_write = tu_edpt_stream_write(p_midi->rhport, ep_str, packets, n_bytes);
+  (void)tu_edpt_stream_write_xfer(p_midi->rhport, ep_str);
+
+  return n_write >> 2u;
+}
+
 //--------------------------------------------------------------------+
 // USBD Driver API
 //--------------------------------------------------------------------+
@@ -378,72 +315,64 @@ void midid_init(void) {
   tu_memclr(_midid_itf, sizeof(_midid_itf));
 
   for (uint8_t i = 0; i < CFG_TUD_MIDI; i++) {
-    midid_interface_t* midi = &_midid_itf[i];
-
-    // config fifo
-    tu_fifo_config(&midi->rx_ff, midi->rx_ff_buf, CFG_TUD_MIDI_RX_BUFSIZE, 1, false); // true, true
-    tu_fifo_config(&midi->tx_ff, midi->tx_ff_buf, CFG_TUD_MIDI_TX_BUFSIZE, 1, false); // OBVS.
+    midid_interface_t *p_midi  = &_midid_itf[i];
+    midid_epbuf_t     *p_epbuf = &_midid_epbuf[i];
 
-    #if CFG_FIFO_MUTEX
-    osal_mutex_t mutex_rd = osal_mutex_create(&midi->rx_ff_mutex);
-    osal_mutex_t mutex_wr = osal_mutex_create(&midi->tx_ff_mutex);
-    TU_ASSERT(mutex_wr != NULL && mutex_wr != NULL, );
+    tu_edpt_stream_init(
+        &p_midi->ep_stream.rx, false, false, false, p_midi->ep_stream.rx_ff_buf, CFG_TUD_MIDI_RX_BUFSIZE,
+        p_epbuf->epout, CFG_TUD_MIDI_EP_BUFSIZE);
 
-    tu_fifo_config_mutex(&midi->rx_ff, NULL, mutex_rd);
-    tu_fifo_config_mutex(&midi->tx_ff, mutex_wr, NULL);
-    #endif
+    tu_edpt_stream_init(
+        &p_midi->ep_stream.tx, false, true, false, p_midi->ep_stream.tx_ff_buf, CFG_TUD_MIDI_TX_BUFSIZE, p_epbuf->epin,
+        CFG_TUD_MIDI_EP_BUFSIZE);
   }
 }
 
 bool midid_deinit(void) {
-  #if CFG_FIFO_MUTEX
-  for(uint8_t i=0; i<CFG_TUD_MIDI; i++) {
-    midid_interface_t* midi = &_midid_itf[i];
-    osal_mutex_t mutex_rd = midi->rx_ff.mutex_rd;
-    osal_mutex_t mutex_wr = midi->tx_ff.mutex_wr;
-
-    if (mutex_rd) {
-      osal_mutex_delete(mutex_rd);
-      tu_fifo_config_mutex(&midi->rx_ff, NULL, NULL);
-    }
-
-    if (mutex_wr) {
-      osal_mutex_delete(mutex_wr);
-      tu_fifo_config_mutex(&midi->tx_ff, NULL, NULL);
-    }
+  for (uint8_t i = 0; i < CFG_TUD_MIDI; i++) {
+    midid_interface_t *p_midi = &_midid_itf[i];
+    tu_edpt_stream_deinit(&p_midi->ep_stream.rx);
+    tu_edpt_stream_deinit(&p_midi->ep_stream.tx);
   }
-  #endif
-
   return true;
 }
 
-void midid_reset(uint8_t rhport)
-{
-  (void) rhport;
+void midid_reset(uint8_t rhport) {
+  (void)rhport;
+  for (uint8_t i = 0; i < CFG_TUD_MIDI; i++) {
+    midid_interface_t *p_midi = &_midid_itf[i];
+    tu_memclr(p_midi, ITF_MEM_RESET_SIZE);
+
+    tu_edpt_stream_clear(&p_midi->ep_stream.rx);
+    tu_edpt_stream_close(&p_midi->ep_stream.rx);
+
+    tu_edpt_stream_clear(&p_midi->ep_stream.tx);
+    tu_edpt_stream_close(&p_midi->ep_stream.tx);
+  }
+}
 
-  for(uint8_t i=0; i<CFG_TUD_MIDI; i++)
-  {
-    midid_interface_t* midi = &_midid_itf[i];
-    tu_memclr(midi, ITF_MEM_RESET_SIZE);
-    tu_fifo_clear(&midi->rx_ff);
-    tu_fifo_clear(&midi->tx_ff);
+TU_ATTR_ALWAYS_INLINE static inline uint8_t find_midi_itf(uint8_t ep_addr) {
+  for (uint8_t idx = 0; idx < CFG_TUD_MIDI; idx++) {
+    const midid_interface_t *p_midi = &_midid_itf[idx];
+    if (ep_addr == p_midi->ep_stream.rx.ep_addr || ep_addr == p_midi->ep_stream.tx.ep_addr) {
+      return idx;
+    }
   }
+  return TUSB_INDEX_INVALID_8;
 }
 
-uint16_t midid_open(uint8_t rhport, const tusb_desc_interface_t* desc_itf, uint16_t max_len) {
-  uint16_t drv_len = 0;
-  uint8_t const * p_desc = (uint8_t const *)desc_itf;
+uint16_t midid_open(uint8_t rhport, const tusb_desc_interface_t *desc_itf, uint16_t max_len) {
+  const uint8_t *p_desc   = (const uint8_t *)desc_itf;
+  const uint8_t *desc_end = p_desc + max_len;
 
   // 1st Interface is Audio Control v1 (optional)
   if (TUSB_CLASS_AUDIO               == desc_itf->bInterfaceClass    &&
       AUDIO_SUBCLASS_CONTROL         == desc_itf->bInterfaceSubClass &&
       AUDIO_FUNC_PROTOCOL_CODE_UNDEF == desc_itf->bInterfaceProtocol) {
-    drv_len = tu_desc_len(desc_itf);
     p_desc = tu_desc_next(desc_itf);
     // Skip Class Specific descriptors
-    while (TUSB_DESC_CS_INTERFACE == tu_desc_type(p_desc) && drv_len <= max_len) {
-      drv_len += tu_desc_len(p_desc);
-      p_desc   = tu_desc_next(p_desc);
+    while (tu_desc_in_bounds(p_desc, desc_end) && TUSB_DESC_CS_INTERFACE == tu_desc_type(p_desc)) {
+      p_desc = tu_desc_next(p_desc);
     }
   }
 
@@ -451,59 +380,48 @@ uint16_t midid_open(uint8_t rhport, const tusb_desc_interface_t* desc_itf, uint1
   TU_VERIFY(TUSB_DESC_INTERFACE == tu_desc_type(p_desc), 0);
   const tusb_desc_interface_t* desc_midi = (const tusb_desc_interface_t*) p_desc;
 
-  TU_VERIFY(TUSB_CLASS_AUDIO               == desc_midi->bInterfaceClass    &&
-            AUDIO_SUBCLASS_MIDI_STREAMING  == desc_midi->bInterfaceSubClass &&
-            AUDIO_FUNC_PROTOCOL_CODE_UNDEF == desc_midi->bInterfaceProtocol, 0);
+  TU_VERIFY(TUSB_CLASS_AUDIO == desc_midi->bInterfaceClass &&
+              AUDIO_SUBCLASS_MIDI_STREAMING == desc_midi->bInterfaceSubClass &&
+              AUDIO_FUNC_PROTOCOL_CODE_UNDEF == desc_midi->bInterfaceProtocol,
+            0);
 
-  // Find available interface
-  midid_interface_t * p_midi = NULL;
-  uint8_t idx;
-  for(idx=0; idx<CFG_TUD_MIDI; idx++) {
-    if ( _midid_itf[idx].ep_in == 0 && _midid_itf[idx].ep_out == 0 ) {
-      p_midi = &_midid_itf[idx];
-      break;
-    }
-  }
-  TU_ASSERT(p_midi);
+  uint8_t idx = find_midi_itf(0); // find unused interface
+  TU_ASSERT(idx < CFG_TUD_MIDI, 0);
+  midid_interface_t *p_midi = &_midid_itf[idx];
 
+  p_midi->rhport  = rhport;
   p_midi->itf_num = desc_midi->bInterfaceNumber;
   (void) p_midi->itf_num;
 
-  // next descriptor
-  drv_len += tu_desc_len(p_desc);
-  p_desc   = tu_desc_next(p_desc);
+  p_desc = tu_desc_next(p_desc);
 
   // Find and open endpoint descriptors
-  uint8_t found_endpoints = 0;
-  while ( (found_endpoints < desc_midi->bNumEndpoints) && (drv_len <= max_len)  )
-  {
-    if ( TUSB_DESC_ENDPOINT == tu_desc_type(p_desc) )
-    {
-      TU_ASSERT(usbd_edpt_open(rhport, (const tusb_desc_endpoint_t*) p_desc), 0);
-      uint8_t ep_addr = ((const tusb_desc_endpoint_t*) p_desc)->bEndpointAddress;
+  uint8_t found_ep = 0;
+  while ((found_ep < desc_midi->bNumEndpoints) && tu_desc_in_bounds(p_desc, desc_end)) {
+    if (TUSB_DESC_ENDPOINT == tu_desc_type(p_desc)) {
+      const tusb_desc_endpoint_t *desc_ep = (const tusb_desc_endpoint_t *)p_desc;
+      TU_ASSERT(usbd_edpt_open(rhport, desc_ep), 0);
+      const uint8_t ep_addr = ((const tusb_desc_endpoint_t *)p_desc)->bEndpointAddress;
 
-      if (tu_edpt_dir(ep_addr) == TUSB_DIR_IN)
-      {
-        p_midi->ep_in = ep_addr;
+      if (tu_edpt_dir(ep_addr) == TUSB_DIR_IN) {
+        tu_edpt_stream_t *stream_tx = &p_midi->ep_stream.tx;
+        tu_edpt_stream_open(stream_tx, desc_ep);
+        tu_edpt_stream_clear(stream_tx);
       } else {
-        p_midi->ep_out = ep_addr;
+        tu_edpt_stream_t *stream_rx = &p_midi->ep_stream.rx;
+        tu_edpt_stream_open(stream_rx, desc_ep);
+        tu_edpt_stream_clear(stream_rx);
+        TU_ASSERT(tu_edpt_stream_read_xfer(rhport, stream_rx) > 0, 0); // prepare to receive data
       }
 
-      // Class Specific MIDI Stream endpoint descriptor
-      drv_len += tu_desc_len(p_desc);
-      p_desc   = tu_desc_next(p_desc);
-
-      found_endpoints += 1;
+      p_desc = tu_desc_next(p_desc);                                   // skip CS Endpoint descriptor
+      found_ep++;
     }
 
-    drv_len += tu_desc_len(p_desc);
-    p_desc   = tu_desc_next(p_desc);
+    p_desc = tu_desc_next(p_desc);
   }
 
-  // Prepare for incoming data
-  _prep_out_transaction(idx);
-
-  return drv_len;
+  return (uint16_t)(p_desc - (const uint8_t *)desc_itf);
 }
 
 // Invoked when a control transfer occurred on an interface of this class
@@ -514,44 +432,31 @@ bool midid_control_xfer_cb(uint8_t rhport, uint8_t stage, const tusb_control_req
   return false; // driver doesn't support any request yet
 }
 
-bool midid_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint32_t xferred_bytes)
-{
-  (void) result;
-  (void) rhport;
-
-  uint8_t idx;
-  midid_interface_t* p_midi;
+bool midid_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint32_t xferred_bytes) {
+  (void)result;
 
-  // Identify which interface to use
-  for (idx = 0; idx < CFG_TUD_MIDI; idx++) {
-    p_midi = &_midid_itf[idx];
-    if ((ep_addr == p_midi->ep_out) || (ep_addr == p_midi->ep_in)) {
-      break;
-    }
-  }
+  uint8_t idx = find_midi_itf(ep_addr);
   TU_ASSERT(idx < CFG_TUD_MIDI);
+  midid_interface_t *p_midi = &_midid_itf[idx];
 
-  // receive new data
-  if (ep_addr == p_midi->ep_out) {
-    tu_fifo_write_n(&p_midi->rx_ff, _midid_epbuf[idx].epout, (uint16_t)xferred_bytes);
+  tu_edpt_stream_t *ep_st_rx = &p_midi->ep_stream.rx;
+  tu_edpt_stream_t *ep_st_tx = &p_midi->ep_stream.tx;
 
-    // invoke receive callback if available
-    tud_midi_rx_cb(idx);
-
-    // prepare for next
-    // TODO for now ep_out is not used by public API therefore there is no race condition,
-    // and does not need to claim like ep_in
-    _prep_out_transaction(idx);
-  } else if (ep_addr == p_midi->ep_in) {
-    if (0 == write_flush(idx)) {
-      // If there is no data left, a ZLP should be sent if
-      // xferred_bytes is multiple of EP size and not zero
-      if (!tu_fifo_count(&p_midi->tx_ff) && xferred_bytes && (0 == (xferred_bytes % CFG_TUD_MIDI_EP_BUFSIZE))) {
-        if (usbd_edpt_claim(rhport, p_midi->ep_in)) {
-          usbd_edpt_xfer(rhport, p_midi->ep_in, NULL, 0);
-        }
-      }
+  if (ep_addr == ep_st_rx->ep_addr) {
+    // Received new data: put into stream's fifo
+    if (result == XFER_RESULT_SUCCESS) {
+      tu_edpt_stream_read_xfer_complete(ep_st_rx, xferred_bytes);
+      tud_midi_rx_cb(idx);                      // invoke callback
     }
+    tu_edpt_stream_read_xfer(rhport, ep_st_rx); // prepare for next data
+  } else if (ep_addr == ep_st_tx->ep_addr && result == XFER_RESULT_SUCCESS) {
+    // sent complete: try to send more if possible
+    if (0 == tu_edpt_stream_write_xfer(rhport, ep_st_tx)) {
+      // If there is no data left, a ZLP should be sent if needed
+      (void)tu_edpt_stream_write_zlp_if_needed(rhport, ep_st_tx, xferred_bytes);
+    }
+  } else {
+    return false;
   }
 
   return true;
diff --git a/src/class/midi/midi_device.h b/src/class/midi/midi_device.h
index c2c6e9859..ddbc2f9f0 100644
--- a/src/class/midi/midi_device.h
+++ b/src/class/midi/midi_device.h
@@ -24,8 +24,8 @@
  * This file is part of the TinyUSB stack.
  */
 
-#ifndef _TUSB_MIDI_DEVICE_H_
-#define _TUSB_MIDI_DEVICE_H_
+#ifndef TUSB_MIDI_DEVICE_H_
+#define TUSB_MIDI_DEVICE_H_
 
 #include "class/audio/audio.h"
 #include "midi.h"
@@ -36,21 +36,21 @@
 
 #if !defined(CFG_TUD_MIDI_EP_BUFSIZE) && defined(CFG_TUD_MIDI_EPSIZE)
   #warning CFG_TUD_MIDI_EPSIZE is renamed to CFG_TUD_MIDI_EP_BUFSIZE, please update to use the new name
-  #define CFG_TUD_MIDI_EP_BUFSIZE    CFG_TUD_MIDI_EPSIZE
+  #define CFG_TUD_MIDI_EP_BUFSIZE CFG_TUD_MIDI_EPSIZE
 #endif
 
 #ifndef CFG_TUD_MIDI_EP_BUFSIZE
-  #define CFG_TUD_MIDI_EP_BUFSIZE     (TUD_OPT_HIGH_SPEED ? 512 : 64)
+  #define CFG_TUD_MIDI_EP_BUFSIZE (TUD_OPT_HIGH_SPEED ? 512 : 64)
 #endif
 
 #ifdef __cplusplus
- extern "C" {
+extern "C" {
 #endif
 
-/** \addtogroup MIDI_Serial Serial
- *  @{
- *  \defgroup   MIDI_Serial_Device Device
- *  @{ */
+//--------------------------------------------------------------------+
+// Application Callback API (optional)
+//--------------------------------------------------------------------+
+void tud_midi_rx_cb(uint8_t itf);
 
 //--------------------------------------------------------------------+
 // Application API (Multiple Interfaces)
@@ -58,117 +58,77 @@
 //--------------------------------------------------------------------+
 
 // Check if midi interface is mounted
-bool     tud_midi_n_mounted      (uint8_t itf);
+bool tud_midi_n_mounted(uint8_t itf);
 
 // Get the number of bytes available for reading
-uint32_t tud_midi_n_available    (uint8_t itf, uint8_t cable_num);
-
-// Read byte stream              (legacy)
-uint32_t tud_midi_n_stream_read  (uint8_t itf, uint8_t cable_num, void* buffer, uint32_t bufsize);
-
-// Write byte Stream             (legacy)
-uint32_t tud_midi_n_stream_write (uint8_t itf, uint8_t cable_num, uint8_t const* buffer, uint32_t bufsize);
-
-// Read event packet             (4 bytes)
-bool     tud_midi_n_packet_read  (uint8_t itf, uint8_t packet[4]);
-
-// Write event packet            (4 bytes)
-bool     tud_midi_n_packet_write (uint8_t itf, uint8_t const packet[4]);
+uint32_t tud_midi_n_available(uint8_t itf, uint8_t cable_num);
 
-//--------------------------------------------------------------------+
-// Application API (Single Interface)
-//--------------------------------------------------------------------+
-static inline bool     tud_midi_mounted      (void);
-static inline uint32_t tud_midi_available    (void);
-
-static inline uint32_t tud_midi_stream_read  (void* buffer, uint32_t bufsize);
-static inline uint32_t tud_midi_stream_write (uint8_t cable_num, uint8_t const* buffer, uint32_t bufsize);
-
-static inline bool     tud_midi_packet_read  (uint8_t packet[4]);
-static inline bool     tud_midi_packet_write (uint8_t const packet[4]);
-
-//------------- Deprecated API name  -------------//
-// TODO remove after 0.10.0 release
-
-TU_ATTR_DEPRECATED("tud_midi_read() is renamed to tud_midi_stream_read()")
-static inline uint32_t tud_midi_read (void* buffer, uint32_t bufsize)
-{
-  return tud_midi_stream_read(buffer, bufsize);
-}
+// Read byte stream (legacy)
+uint32_t tud_midi_n_stream_read(uint8_t itf, uint8_t cable_num, void *buffer, uint32_t bufsize);
 
-TU_ATTR_DEPRECATED("tud_midi_write() is renamed to tud_midi_stream_write()")
-static inline uint32_t tud_midi_write(uint8_t cable_num, uint8_t const* buffer, uint32_t bufsize)
-{
-  return tud_midi_stream_write(cable_num, buffer, bufsize);
-}
+// Write byte Stream (legacy)
+uint32_t tud_midi_n_stream_write(uint8_t itf, uint8_t cable_num, const uint8_t *buffer, uint32_t bufsize);
 
+// Read an event 4-byte packet
+bool tud_midi_n_packet_read(uint8_t itf, uint8_t packet[4]);
 
-TU_ATTR_DEPRECATED("tud_midi_send() is renamed to tud_midi_packet_write()")
-static inline bool tud_midi_send(uint8_t packet[4])
-{
-  return tud_midi_packet_write(packet);
-}
+// Read multiple event packets, return number of read packets
+uint32_t tud_midi_n_packet_read_n(uint8_t itf, uint8_t packets[], uint32_t max_packets);
 
-TU_ATTR_DEPRECATED("tud_midi_receive() is renamed to tud_midi_packet_read()")
-static inline bool tud_midi_receive(uint8_t packet[4])
-{
-  return tud_midi_packet_read(packet);
-}
+// Write an event 4-byte packet
+bool tud_midi_n_packet_write(uint8_t itf, const uint8_t packet[4]);
 
-//--------------------------------------------------------------------+
-// Application Callback API (optional)
-//--------------------------------------------------------------------+
-void tud_midi_rx_cb(uint8_t itf);
+// Write multiple event packets, return number of written packets
+uint32_t tud_midi_n_packet_write_n(uint8_t itf, const uint8_t packets[], uint32_t n_packets);
 
 //--------------------------------------------------------------------+
-// Inline Functions
+// Application API (Single Interface)
 //--------------------------------------------------------------------+
-
-static inline bool tud_midi_mounted (void)
-{
+TU_ATTR_ALWAYS_INLINE static inline bool tud_midi_mounted(void) {
   return tud_midi_n_mounted(0);
 }
 
-static inline uint32_t tud_midi_available (void)
-{
+TU_ATTR_ALWAYS_INLINE static inline uint32_t tud_midi_available(void) {
   return tud_midi_n_available(0, 0);
 }
 
-static inline uint32_t tud_midi_stream_read (void* buffer, uint32_t bufsize)
-{
+TU_ATTR_ALWAYS_INLINE static inline uint32_t tud_midi_stream_read(void *buffer, uint32_t bufsize) {
   return tud_midi_n_stream_read(0, 0, buffer, bufsize);
 }
 
-static inline uint32_t tud_midi_stream_write (uint8_t cable_num, uint8_t const* buffer, uint32_t bufsize)
-{
+TU_ATTR_ALWAYS_INLINE static inline uint32_t
+tud_midi_stream_write(uint8_t cable_num, const uint8_t *buffer, uint32_t bufsize) {
   return tud_midi_n_stream_write(0, cable_num, buffer, bufsize);
 }
 
-static inline bool tud_midi_packet_read (uint8_t packet[4])
-{
+TU_ATTR_ALWAYS_INLINE static inline bool tud_midi_packet_read(uint8_t packet[4]) {
   return tud_midi_n_packet_read(0, packet);
 }
 
-static inline bool tud_midi_packet_write (uint8_t const packet[4])
-{
+TU_ATTR_ALWAYS_INLINE static inline uint32_t tud_midi_packet_read_n(uint8_t packets[], uint32_t max_packets) {
+  return tud_midi_n_packet_read_n(0, packets, max_packets);
+}
+
+TU_ATTR_ALWAYS_INLINE static inline bool tud_midi_packet_write(const uint8_t packet[4]) {
   return tud_midi_n_packet_write(0, packet);
 }
 
+TU_ATTR_ALWAYS_INLINE static inline uint32_t tud_midi_packet_write_n(const uint8_t packets[], uint32_t n_packets) {
+  return tud_midi_n_packet_write_n(0, packets, n_packets);
+}
+
 //--------------------------------------------------------------------+
 // Internal Class Driver API
 //--------------------------------------------------------------------+
-void     midid_init            (void);
-bool     midid_deinit          (void);
-void     midid_reset           (uint8_t rhport);
-uint16_t midid_open            (uint8_t rhport, tusb_desc_interface_t const * itf_desc, uint16_t max_len);
-bool     midid_control_xfer_cb (uint8_t rhport, uint8_t stage, tusb_control_request_t const * request);
-bool     midid_xfer_cb         (uint8_t rhport, uint8_t edpt_addr, xfer_result_t result, uint32_t xferred_bytes);
+void     midid_init(void);
+bool     midid_deinit(void);
+void     midid_reset(uint8_t rhport);
+uint16_t midid_open(uint8_t rhport, const tusb_desc_interface_t *itf_desc, uint16_t max_len);
+bool     midid_control_xfer_cb(uint8_t rhport, uint8_t stage, const tusb_control_request_t *request);
+bool     midid_xfer_cb(uint8_t rhport, uint8_t edpt_addr, xfer_result_t result, uint32_t xferred_bytes);
 
 #ifdef __cplusplus
- }
+}
 #endif
 
-#endif /* _TUSB_MIDI_DEVICE_H_ */
-
-/** @} */
-/** @} */
+#endif
diff --git a/src/class/midi/midi_host.c b/src/class/midi/midi_host.c
index e6ace316c..07062875c 100644
--- a/src/class/midi/midi_host.c
+++ b/src/class/midi/midi_host.c
@@ -59,9 +59,6 @@ typedef struct {
   uint8_t iInterface;
   uint8_t itf_count;        // number of interface including Audio Control + MIDI streaming
 
-  uint8_t ep_in;          // IN endpoint address
-  uint8_t ep_out;         // OUT endpoint address
-
   uint8_t rx_cable_count;  // IN endpoint CS descriptor bNumEmbMIDIJack value
   uint8_t tx_cable_count;  // OUT endpoint CS descriptor bNumEmbMIDIJack value
 
@@ -147,8 +144,6 @@ void midih_close(uint8_t daddr) {
       TU_LOG_DRV("  MIDI close addr = %u index = %u\r\n", daddr, idx);
       tuh_midi_umount_cb(idx);
 
-      p_midi->ep_in = 0;
-      p_midi->ep_out = 0;
       p_midi->bInterfaceNumber = 0;
       p_midi->rx_cable_count = 0;
       p_midi->tx_cable_count = 0;
@@ -169,23 +164,25 @@ bool midih_xfer_cb(uint8_t dev_addr, uint8_t ep_addr, xfer_result_t result, uint
   const uint8_t idx = get_idx_by_ep_addr(dev_addr, ep_addr);
   TU_VERIFY(idx < CFG_TUH_MIDI);
   midih_interface_t *p_midi = &_midi_host[idx];
+  tu_edpt_stream_t  *ep_str_rx = &p_midi->ep_stream.rx;
+  tu_edpt_stream_t  *ep_str_tx = &p_midi->ep_stream.tx;
 
-  if (ep_addr == p_midi->ep_stream.rx.ep_addr) {
+  if (ep_addr == ep_str_rx->ep_addr) {
     // receive new data, put it into FIFO and invoke callback if available
     // Note: some devices send back all zero packets even if there is no data ready
-    if (xferred_bytes && !tu_mem_is_zero(p_midi->ep_stream.rx.ep_buf, xferred_bytes)) {
-      tu_edpt_stream_read_xfer_complete(&p_midi->ep_stream.rx, xferred_bytes);
+    if (xferred_bytes && !tu_mem_is_zero(ep_str_rx->ep_buf, xferred_bytes)) {
+      tu_edpt_stream_read_xfer_complete(ep_str_rx, xferred_bytes);
       tuh_midi_rx_cb(idx, xferred_bytes);
     }
 
-    tu_edpt_stream_read_xfer(dev_addr, &p_midi->ep_stream.rx); // prepare for next transfer
-  } else if (ep_addr == p_midi->ep_stream.tx.ep_addr) {
+    tu_edpt_stream_read_xfer(dev_addr, ep_str_rx); // prepare for next transfer
+  } else if (ep_addr == ep_str_tx->ep_addr) {
     tuh_midi_tx_cb(idx, xferred_bytes);
 
-    if (0 == tu_edpt_stream_write_xfer(dev_addr, &p_midi->ep_stream.tx)) {
+    if (0 == tu_edpt_stream_write_xfer(dev_addr, ep_str_tx)) {
       // If there is no data left, a ZLP should be sent if
       // xferred_bytes is multiple of EP size and not zero
-      tu_edpt_stream_write_zlp_if_needed(dev_addr, &p_midi->ep_stream.tx, xferred_bytes);
+      tu_edpt_stream_write_zlp_if_needed(dev_addr, ep_str_tx, xferred_bytes);
     }
   }
 
@@ -220,11 +217,11 @@ bool midih_open(uint8_t rhport, uint8_t dev_addr, tusb_desc_interface_t const *d
   // driver after parsing the audio control interface and then resume parsing
   // the streaming audio interface.
   if (AUDIO_SUBCLASS_CONTROL == desc_itf->bInterfaceSubClass) {
-    TU_VERIFY(max_len > 2*sizeof(tusb_desc_interface_t) + sizeof(audio_desc_cs_ac_interface_t));
+    TU_VERIFY(max_len > 2*sizeof(tusb_desc_interface_t) + sizeof(midi10_desc_cs_ac_interface_t));
 
     p_desc = tu_desc_next(p_desc);
     TU_VERIFY(tu_desc_type(p_desc) == TUSB_DESC_CS_INTERFACE &&
-              tu_desc_subtype(p_desc) == AUDIO_CS_AC_INTERFACE_HEADER);
+              tu_desc_subtype(p_desc) == AUDIO10_CS_AC_INTERFACE_HEADER);
     desc_cb.desc_audio_control = desc_itf;
 
     p_desc = tu_desc_next(p_desc);
@@ -295,21 +292,20 @@ bool midih_open(uint8_t rhport, uint8_t dev_addr, tusb_desc_interface_t const *d
         const midi_desc_cs_endpoint_t *p_csep = (const midi_desc_cs_endpoint_t *) p_desc;
 
         TU_LOG_DRV("  Endpoint and CS_Endpoint descriptor %02x\r\n", p_ep->bEndpointAddress);
+        tu_edpt_stream_t *ep_stream;
         if (tu_edpt_dir(p_ep->bEndpointAddress) == TUSB_DIR_OUT) {
-          p_midi->ep_out = p_ep->bEndpointAddress;
           p_midi->tx_cable_count = p_csep->bNumEmbMIDIJack;
           desc_cb.desc_epout = p_ep;
-
-          TU_ASSERT(tuh_edpt_open(dev_addr, p_ep));
-          tu_edpt_stream_open(&p_midi->ep_stream.tx, p_ep);
+          ep_stream              = &p_midi->ep_stream.tx;
         } else {
-          p_midi->ep_in = p_ep->bEndpointAddress;
           p_midi->rx_cable_count = p_csep->bNumEmbMIDIJack;
-          desc_cb.desc_epin = p_ep;
-
-          TU_ASSERT(tuh_edpt_open(dev_addr, p_ep));
-          tu_edpt_stream_open(&p_midi->ep_stream.rx, p_ep);
+          desc_cb.desc_epin      = p_ep;
+          ep_stream              = &p_midi->ep_stream.rx;
         }
+        TU_ASSERT(tuh_edpt_open(dev_addr, p_ep));
+        tu_edpt_stream_open(ep_stream, p_ep);
+        tu_edpt_stream_clear(ep_stream);
+
         break;
       }
 
@@ -379,8 +375,14 @@ bool tuh_midi_itf_get_info(uint8_t idx, tuh_itf_info_t* info) {
   desc->bDescriptorType    = TUSB_DESC_INTERFACE;
 
   desc->bInterfaceNumber   = p_midi->bInterfaceNumber;
-  desc->bAlternateSetting  = 0;
-  desc->bNumEndpoints      = (uint8_t)((p_midi->ep_in != 0 ? 1:0) + (p_midi->ep_out != 0 ? 1:0));
+  desc->bAlternateSetting = 0;
+  desc->bNumEndpoints     = 0;
+  if (tu_edpt_stream_is_opened(&p_midi->ep_stream.tx)) {
+    desc->bNumEndpoints++;
+  }
+  if (tu_edpt_stream_is_opened(&p_midi->ep_stream.rx)) {
+    desc->bNumEndpoints++;
+  }
   desc->bInterfaceClass    = TUSB_CLASS_AUDIO;
   desc->bInterfaceSubClass = AUDIO_SUBCLASS_MIDI_STREAMING;
   desc->bInterfaceProtocol = 0;
diff --git a/src/class/msc/msc.h b/src/class/msc/msc.h
index b2b44eac4..3b5d4a855 100644
--- a/src/class/msc/msc.h
+++ b/src/class/msc/msc.h
@@ -24,8 +24,8 @@
  * This file is part of the TinyUSB stack.
  */
 
-#ifndef _TUSB_MSC_H_
-#define _TUSB_MSC_H_
+#ifndef TUSB_MSC_H_
+#define TUSB_MSC_H_
 
 #include "common/tusb_common.h"
 
@@ -398,4 +398,4 @@ TU_VERIFY_STATIC(sizeof(scsi_write10_t) == 10, "size is not correct");
  }
 #endif
 
-#endif /* _TUSB_MSC_H_ */
+#endif /* TUSB_MSC_H_ */
diff --git a/src/class/msc/msc_device.c b/src/class/msc/msc_device.c
index b0eafd5da..15bfafc35 100644
--- a/src/class/msc/msc_device.c
+++ b/src/class/msc/msc_device.c
@@ -83,7 +83,7 @@ typedef struct {
   uint8_t add_sense_code;
   uint8_t add_sense_qualifier;
 
-  uint8_t pending_io; // pending async IO
+  bool pending_io; // pending async IO
 }mscd_interface_t;
 
 static mscd_interface_t _mscd_itf;
@@ -92,6 +92,8 @@ CFG_TUD_MEM_SECTION static struct {
   TUD_EPBUF_DEF(buf, CFG_TUD_MSC_EP_BUFSIZE);
 } _mscd_epbuf;
 
+TU_VERIFY_STATIC(CFG_TUD_MSC_EP_BUFSIZE >= 64, "CFG_TUD_MSC_EP_BUFSIZE must be at least 64");
+
 //--------------------------------------------------------------------+
 // INTERNAL OBJECT & FUNCTION DECLARATION
 //--------------------------------------------------------------------+
@@ -107,19 +109,19 @@ TU_ATTR_ALWAYS_INLINE static inline bool is_data_in(uint8_t dir) {
   return tu_bit_test(dir, 7);
 }
 
-static inline bool send_csw(mscd_interface_t* p_msc) {
+TU_ATTR_ALWAYS_INLINE static inline bool send_csw(mscd_interface_t* p_msc) {
   // Data residue is always = host expect - actual transferred
   uint8_t rhport = p_msc->rhport;
   p_msc->csw.data_residue = p_msc->cbw.total_bytes - p_msc->xferred_len;
   p_msc->stage = MSC_STAGE_STATUS_SENT;
-  memcpy(_mscd_epbuf.buf, &p_msc->csw, sizeof(msc_csw_t));
-  return usbd_edpt_xfer(rhport, p_msc->ep_in , _mscd_epbuf.buf, sizeof(msc_csw_t));
+  memcpy(_mscd_epbuf.buf, &p_msc->csw, sizeof(msc_csw_t)); //-V1086
+  return usbd_edpt_xfer(rhport, p_msc->ep_in , _mscd_epbuf.buf, sizeof(msc_csw_t), false);
 }
 
-static inline bool prepare_cbw(mscd_interface_t* p_msc) {
+TU_ATTR_ALWAYS_INLINE static inline bool prepare_cbw(mscd_interface_t* p_msc) {
   uint8_t rhport = p_msc->rhport;
   p_msc->stage = MSC_STAGE_CMD;
-  return usbd_edpt_xfer(rhport, p_msc->ep_out,  _mscd_epbuf.buf, sizeof(msc_cbw_t));
+  return usbd_edpt_xfer(rhport, p_msc->ep_out,  _mscd_epbuf.buf, sizeof(msc_cbw_t), false);
 }
 
 static void fail_scsi_op(mscd_interface_t* p_msc, uint8_t status) {
@@ -133,7 +135,7 @@ static void fail_scsi_op(mscd_interface_t* p_msc, uint8_t status) {
 
   // failed but sense key is not set: default to Illegal Request
   if (p_msc->sense_key == 0) {
-    tud_msc_set_sense(p_cbw->lun, SCSI_SENSE_ILLEGAL_REQUEST, 0x20, 0x00);
+    (void) tud_msc_set_sense(p_cbw->lun, SCSI_SENSE_ILLEGAL_REQUEST, 0x20, 0x00);
   }
 
   // If there is data stage and not yet complete, stall it
@@ -146,18 +148,18 @@ static void fail_scsi_op(mscd_interface_t* p_msc, uint8_t status) {
   }
 }
 
-static inline uint32_t rdwr10_get_lba(uint8_t const command[]) {
+TU_ATTR_ALWAYS_INLINE static inline uint32_t rdwr10_get_lba(uint8_t const command[]) {
   // use offsetof to avoid pointer to the odd/unaligned address
   const uint32_t lba = tu_unaligned_read32(command + offsetof(scsi_write10_t, lba));
   return tu_ntohl(lba); // lba is in Big Endian
 }
 
-static inline uint16_t rdwr10_get_blockcount(msc_cbw_t const* cbw) {
+TU_ATTR_ALWAYS_INLINE static inline uint16_t rdwr10_get_blockcount(msc_cbw_t const* cbw) {
   uint16_t const block_count = tu_unaligned_read16(cbw->command + offsetof(scsi_write10_t, block_count));
   return tu_ntohs(block_count);
 }
 
-static inline uint16_t rdwr10_get_blocksize(msc_cbw_t const* cbw) {
+TU_ATTR_ALWAYS_INLINE static inline uint16_t rdwr10_get_blocksize(msc_cbw_t const* cbw) {
   // first extract block count in the command
   uint16_t const block_count = rdwr10_get_blockcount(cbw);
   if (block_count == 0) {
@@ -171,7 +173,7 @@ static uint8_t rdwr10_validate_cmd(msc_cbw_t const* cbw) {
   uint16_t const block_count = rdwr10_get_blockcount(cbw);
 
   if (cbw->total_bytes == 0) {
-    if (block_count) {
+    if (block_count > 0) {
       TU_LOG_DRV("  SCSI case 2 (Hn < Di) or case 3 (Hn < Do) \r\n");
       status = MSC_CSW_STATUS_PHASE_ERROR;
     } else {
@@ -190,6 +192,8 @@ static uint8_t rdwr10_validate_cmd(msc_cbw_t const* cbw) {
     } else if (cbw->total_bytes / block_count == 0) {
       TU_LOG_DRV(" Computed block size = 0. SCSI case 7 Hi < Di (READ10) or case 13 Ho < Do (WRIT10)\r\n");
       status = MSC_CSW_STATUS_PHASE_ERROR;
+    } else {
+      // nothing to do
     }
   }
 
@@ -309,7 +313,7 @@ bool tud_msc_set_sense(uint8_t lun, uint8_t sense_key, uint8_t add_sense_code, u
 
 TU_ATTR_ALWAYS_INLINE static inline void set_sense_medium_not_present(uint8_t lun) {
   // default sense is NOT READY, MEDIUM NOT PRESENT
-  tud_msc_set_sense(lun, SCSI_SENSE_NOT_READY, 0x3A, 0x00);
+  (void) tud_msc_set_sense(lun, SCSI_SENSE_NOT_READY, 0x3A, 0x00);
 }
 
 static void proc_async_io_done(void *bytes_io) {
@@ -318,7 +322,7 @@ static void proc_async_io_done(void *bytes_io) {
   const int32_t nbytes = (int32_t) (intptr_t) bytes_io;
   const uint8_t cmd = p_msc->cbw.command[0];
 
-  p_msc->pending_io = 0;
+  p_msc->pending_io = false;
   switch (cmd) {
     case SCSI_CMD_READ_10:
       proc_read_io_data(p_msc, nbytes);
@@ -328,7 +332,7 @@ static void proc_async_io_done(void *bytes_io) {
       proc_write_io_data(p_msc, (uint32_t) nbytes, nbytes);
       break;
 
-    default: break;
+    default: break; // nothing to do
   }
 
   // send status if stage is transitioned to STATUS
@@ -429,6 +433,8 @@ bool mscd_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb_control_request_t
             TU_ASSERT(prepare_cbw(p_msc));
           }
         }
+      } else {
+        // nothing to do
       }
     }
 
@@ -451,7 +457,7 @@ bool mscd_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb_control_request_t
       TU_VERIFY(request->wValue == 0 && request->wLength == 1);
 
       uint8_t maxlun = tud_msc_get_maxlun_cb();
-      TU_VERIFY(maxlun);
+      TU_VERIFY(maxlun != 0);
       maxlun--; // MAX LUN is minus 1 by specs
       tud_control_xfer(rhport, request, &maxlun, 1);
       break;
@@ -510,7 +516,7 @@ bool mscd_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t event, uint32_t
 
         if (status != MSC_CSW_STATUS_PASSED) {
           fail_scsi_op(p_msc, status);
-        } else if (p_cbw->total_bytes) {
+        } else if (p_cbw->total_bytes > 0) {
           if (SCSI_CMD_READ_10 == p_cbw->command[0]) {
             proc_read10_cmd(p_msc);
           } else {
@@ -531,7 +537,7 @@ bool mscd_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t event, uint32_t
           } else {
             // Didn't check for case 9 (Ho > Dn), which requires examining scsi command first
             // but it is OK to just receive data then responded with failed status
-            TU_ASSERT(usbd_edpt_xfer(rhport, p_msc->ep_out, _mscd_epbuf.buf, (uint16_t) p_msc->total_len));
+            TU_ASSERT(usbd_edpt_xfer(rhport, p_msc->ep_out, _mscd_epbuf.buf, (uint16_t) p_msc->total_len, false));
           }
         } else {
           // First process if it is a built-in commands
@@ -547,7 +553,7 @@ bool mscd_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t event, uint32_t
             TU_LOG_DRV("  SCSI unsupported or failed command\r\n");
             fail_scsi_op(p_msc, MSC_CSW_STATUS_FAILED);
           } else if (resplen == 0) {
-            if (p_cbw->total_bytes) {
+            if (p_cbw->total_bytes > 0) {
               // 6.7 The 13 Cases: case 4 (Hi > Dn)
               // TU_LOG_DRV("  SCSI case 4 (Hi > Dn): %lu\r\n", p_cbw->total_bytes);
               fail_scsi_op(p_msc, MSC_CSW_STATUS_FAILED);
@@ -563,7 +569,7 @@ bool mscd_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t event, uint32_t
             } else {
               // cannot return more than host expect
               p_msc->total_len = tu_min32((uint32_t)resplen, p_cbw->total_bytes);
-              TU_ASSERT(usbd_edpt_xfer(rhport, p_msc->ep_in, _mscd_epbuf.buf, (uint16_t) p_msc->total_len));
+              TU_ASSERT(usbd_edpt_xfer(rhport, p_msc->ep_in, _mscd_epbuf.buf, (uint16_t) p_msc->total_len, false));
             }
           }
         }
@@ -647,7 +653,7 @@ bool mscd_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t event, uint32_t
       }
       break;
 
-    default: break;
+    default: break; // nothing to do
   }
 
   if (p_msc->stage == MSC_STAGE_STATUS) {
@@ -683,9 +689,8 @@ static int32_t proc_builtin_scsi(uint8_t lun, uint8_t const scsi_cmd[16], uint8_
       }
       break;
 
-    case SCSI_CMD_START_STOP_UNIT:
+    case SCSI_CMD_START_STOP_UNIT: {
       resplen = 0;
-
       scsi_start_stop_unit_t const* start_stop = (scsi_start_stop_unit_t const*)scsi_cmd;
       if (!tud_msc_start_stop_cb(lun, start_stop->power_condition, start_stop->start, start_stop->load_eject)) {
         // Failed status response
@@ -697,10 +702,10 @@ static int32_t proc_builtin_scsi(uint8_t lun, uint8_t const scsi_cmd[16], uint8_
         }
       }
       break;
+    }
 
-    case SCSI_CMD_PREVENT_ALLOW_MEDIUM_REMOVAL:
+    case SCSI_CMD_PREVENT_ALLOW_MEDIUM_REMOVAL: {
       resplen = 0;
-
       scsi_prevent_allow_medium_removal_t const* prevent_allow = (scsi_prevent_allow_medium_removal_t const*)scsi_cmd;
       if (!tud_msc_prevent_allow_medium_removal_cb(lun, prevent_allow->prohibit_removal, prevent_allow->control)) {
         // Failed status response
@@ -712,7 +717,7 @@ static int32_t proc_builtin_scsi(uint8_t lun, uint8_t const scsi_cmd[16], uint8_
         }
       }
       break;
-
+    }
 
     case SCSI_CMD_READ_CAPACITY_10: {
       uint32_t block_count;
@@ -740,8 +745,8 @@ static int32_t proc_builtin_scsi(uint8_t lun, uint8_t const scsi_cmd[16], uint8_
         resplen = sizeof(read_capa10);
         TU_VERIFY(0 == tu_memcpy_s(buffer, bufsize, &read_capa10, (size_t) resplen));
       }
+      break;
     }
-    break;
 
     case SCSI_CMD_READ_FORMAT_CAPACITY: {
       scsi_read_format_capacity_data_t read_fmt_capa = {
@@ -772,8 +777,8 @@ static int32_t proc_builtin_scsi(uint8_t lun, uint8_t const scsi_cmd[16], uint8_
         resplen = sizeof(read_fmt_capa);
         TU_VERIFY(0 == tu_memcpy_s(buffer, bufsize, &read_fmt_capa, (size_t) resplen));
       }
+      break;
     }
-    break;
 
     case SCSI_CMD_INQUIRY: {
       scsi_inquiry_resp_t *inquiry_rsp = (scsi_inquiry_resp_t *) buffer;
@@ -789,8 +794,8 @@ static int32_t proc_builtin_scsi(uint8_t lun, uint8_t const scsi_cmd[16], uint8_
         tud_msc_inquiry_cb(lun, inquiry_rsp->vendor_id, inquiry_rsp->product_id, inquiry_rsp->product_rev);
         resplen = sizeof(scsi_inquiry_resp_t);
       }
+      break;
     }
-    break;
 
     case SCSI_CMD_MODE_SENSE_6: {
       scsi_mode_sense6_resp_t mode_resp = {
@@ -807,8 +812,8 @@ static int32_t proc_builtin_scsi(uint8_t lun, uint8_t const scsi_cmd[16], uint8_
 
       resplen = sizeof(mode_resp);
       TU_VERIFY(0 == tu_memcpy_s(buffer, bufsize, &mode_resp, (size_t) resplen));
+      break;
     }
-    break;
 
     case SCSI_CMD_REQUEST_SENSE: {
       scsi_sense_fixed_resp_t sense_rsp = {
@@ -828,9 +833,9 @@ static int32_t proc_builtin_scsi(uint8_t lun, uint8_t const scsi_cmd[16], uint8_
       resplen = tud_msc_request_sense_cb(lun, buffer, (uint16_t)bufsize);
 
       // Clear sense data after copy
-      tud_msc_set_sense(lun, 0, 0, 0);
+      (void) tud_msc_set_sense(lun, 0, 0, 0);
+      break;
     }
-    break;
 
     default: resplen = -1;
       break;
@@ -842,6 +847,7 @@ static int32_t proc_builtin_scsi(uint8_t lun, uint8_t const scsi_cmd[16], uint8_
 static void proc_read10_cmd(mscd_interface_t* p_msc) {
   msc_cbw_t const* p_cbw = &p_msc->cbw;
   uint16_t const block_sz = rdwr10_get_blocksize(p_cbw); // already verified non-zero
+  TU_VERIFY(block_sz != 0, );
   // Adjust lba & offset with transferred bytes
   uint32_t const lba = rdwr10_get_lba(p_cbw->command) + (p_msc->xferred_len / block_sz);
   uint32_t const offset = p_msc->xferred_len % block_sz;
@@ -849,10 +855,10 @@ static void proc_read10_cmd(mscd_interface_t* p_msc) {
   // remaining bytes capped at class buffer
   int32_t nbytes = (int32_t)tu_min32(CFG_TUD_MSC_EP_BUFSIZE, p_cbw->total_bytes - p_msc->xferred_len);
 
-  p_msc->pending_io = 1;
+  p_msc->pending_io = true;
   nbytes = tud_msc_read10_cb(p_cbw->lun, lba, offset, _mscd_epbuf.buf, (uint32_t)nbytes);
   if (nbytes != TUD_MSC_RET_ASYNC) {
-    p_msc->pending_io = 0;
+    p_msc->pending_io = false;
     proc_read_io_data(p_msc, nbytes);
   }
 }
@@ -860,7 +866,7 @@ static void proc_read10_cmd(mscd_interface_t* p_msc) {
 static void proc_read_io_data(mscd_interface_t* p_msc, int32_t nbytes) {
   const uint8_t rhport = p_msc->rhport;
   if (nbytes > 0) {
-    TU_ASSERT(usbd_edpt_xfer(rhport, p_msc->ep_in, _mscd_epbuf.buf, (uint16_t) nbytes),);
+    TU_ASSERT(usbd_edpt_xfer(rhport, p_msc->ep_in, _mscd_epbuf.buf, (uint16_t) nbytes, false),);
   } else {
     // nbytes is status
     switch (nbytes) {
@@ -876,19 +882,19 @@ static void proc_read_io_data(mscd_interface_t* p_msc, int32_t nbytes) {
         dcd_event_xfer_complete(rhport, p_msc->ep_in, 0, XFER_RESULT_SUCCESS, false);
         break;
 
-      default: break;
+      default: break; // nothing to do
     }
   }
 }
 
 static void proc_write10_cmd(mscd_interface_t* p_msc) {
   msc_cbw_t const* p_cbw = &p_msc->cbw;
-  bool writable = tud_msc_is_writable_cb(p_cbw->lun);
+  const bool writable = tud_msc_is_writable_cb(p_cbw->lun);
 
   if (!writable) {
     // Not writable, complete this SCSI op with error
     // Sense = Write protected
-    tud_msc_set_sense(p_cbw->lun, SCSI_SENSE_DATA_PROTECT, 0x27, 0x00);
+    (void) tud_msc_set_sense(p_cbw->lun, SCSI_SENSE_DATA_PROTECT, 0x27, 0x00);
     fail_scsi_op(p_msc, MSC_CSW_STATUS_FAILED);
     return;
   }
@@ -896,22 +902,23 @@ static void proc_write10_cmd(mscd_interface_t* p_msc) {
   // remaining bytes capped at class buffer
   uint16_t nbytes = (uint16_t)tu_min32(CFG_TUD_MSC_EP_BUFSIZE, p_cbw->total_bytes - p_msc->xferred_len);
   // Write10 callback will be called later when usb transfer complete
-  TU_ASSERT(usbd_edpt_xfer(p_msc->rhport, p_msc->ep_out, _mscd_epbuf.buf, nbytes),);
+  TU_ASSERT(usbd_edpt_xfer(p_msc->rhport, p_msc->ep_out, _mscd_epbuf.buf, nbytes, false),);
 }
 
 // process new data arrived from WRITE10
 static void proc_write10_host_data(mscd_interface_t* p_msc, uint32_t xferred_bytes) {
   msc_cbw_t const* p_cbw = &p_msc->cbw;
   uint16_t const block_sz = rdwr10_get_blocksize(p_cbw); // already verified non-zero
+  TU_VERIFY(block_sz != 0, );
 
   // Adjust lba & offset with transferred bytes
   uint32_t const lba = rdwr10_get_lba(p_cbw->command) + (p_msc->xferred_len / block_sz);
   uint32_t const offset = p_msc->xferred_len % block_sz;
 
-  p_msc->pending_io = 1;
+  p_msc->pending_io = true;
   int32_t nbytes =  tud_msc_write10_cb(p_cbw->lun, lba, offset, _mscd_epbuf.buf, xferred_bytes);
   if (nbytes != TUD_MSC_RET_ASYNC) {
-    p_msc->pending_io = 0;
+    p_msc->pending_io = false;
     proc_write_io_data(p_msc, xferred_bytes, nbytes);
   }
 }
@@ -927,7 +934,7 @@ static void proc_write_io_data(mscd_interface_t* p_msc, uint32_t xferred_bytes,
         fail_scsi_op(p_msc, MSC_CSW_STATUS_FAILED);
         break;
 
-      default: break;
+      default: break; // nothing to do
     }
   } else {
     if ((uint32_t)nbytes < xferred_bytes) {
diff --git a/src/class/msc/msc_device.h b/src/class/msc/msc_device.h
index 7d898e988..21e24971b 100644
--- a/src/class/msc/msc_device.h
+++ b/src/class/msc/msc_device.h
@@ -24,8 +24,8 @@
  * This file is part of the TinyUSB stack.
  */
 
-#ifndef _TUSB_MSC_DEVICE_H_
-#define _TUSB_MSC_DEVICE_H_
+#ifndef TUSB_MSC_DEVICE_H_
+#define TUSB_MSC_DEVICE_H_
 
 #include "common/tusb_common.h"
 #include "msc.h"
@@ -167,4 +167,4 @@ bool     mscd_xfer_cb         (uint8_t rhport, uint8_t ep_addr, xfer_result_t ev
  }
 #endif
 
-#endif /* _TUSB_MSC_DEVICE_H_ */
+#endif /* TUSB_MSC_DEVICE_H_ */
diff --git a/src/class/msc/msc_host.c b/src/class/msc/msc_host.c
index eb69ae400..daff345c5 100644
--- a/src/class/msc/msc_host.c
+++ b/src/class/msc/msc_host.c
@@ -123,7 +123,10 @@ bool tuh_msc_mounted(uint8_t dev_addr) {
 
 bool tuh_msc_ready(uint8_t dev_addr) {
   msch_interface_t* p_msc = get_itf(dev_addr);
-  return p_msc->mounted && !usbh_edpt_busy(dev_addr, p_msc->ep_in) && !usbh_edpt_busy(dev_addr, p_msc->ep_out);
+  TU_VERIFY(p_msc->mounted);
+  const bool epin_busy = usbh_edpt_busy(dev_addr, p_msc->ep_in);
+  const bool epout_busy = usbh_edpt_busy(dev_addr, p_msc->ep_out);
+  return !epin_busy && !epout_busy;
 }
 
 //--------------------------------------------------------------------+
@@ -152,7 +155,7 @@ bool tuh_msc_scsi_command(uint8_t daddr, msc_cbw_t const* cbw, void* data,
   p_msc->stage = MSC_STAGE_CMD;
 
   if (!usbh_edpt_xfer(daddr, p_msc->ep_out, (uint8_t*) &epbuf->cbw, sizeof(msc_cbw_t))) {
-    usbh_edpt_release(daddr, p_msc->ep_out);
+    (void) usbh_edpt_release(daddr, p_msc->ep_out);
     return false;
   }
 
@@ -191,7 +194,7 @@ bool tuh_msc_inquiry(uint8_t dev_addr, uint8_t lun, scsi_inquiry_resp_t* respons
       .cmd_code     = SCSI_CMD_INQUIRY,
       .alloc_length = sizeof(scsi_inquiry_resp_t)
   };
-  memcpy(cbw.command, &cmd_inquiry, cbw.cmd_len);
+  memcpy(cbw.command, &cmd_inquiry, cbw.cmd_len); //-V1086
 
   return tuh_msc_scsi_command(dev_addr, &cbw, response, complete_cb, arg);
 }
@@ -225,7 +228,7 @@ bool tuh_msc_request_sense(uint8_t dev_addr, uint8_t lun, void* response,
       .cmd_code     = SCSI_CMD_REQUEST_SENSE,
       .alloc_length = 18
   };
-  memcpy(cbw.command, &cmd_request_sense, cbw.cmd_len);
+  memcpy(cbw.command, &cmd_request_sense, cbw.cmd_len); //-V1086
 
   return tuh_msc_scsi_command(dev_addr, &cbw, response, complete_cb, arg);
 }
@@ -247,7 +250,7 @@ bool tuh_msc_read10(uint8_t dev_addr, uint8_t lun, void* buffer, uint32_t lba, u
       .lba         = tu_htonl(lba),
       .block_count = tu_htons(block_count)
   };
-  memcpy(cbw.command, &cmd_read10, cbw.cmd_len);
+  memcpy(cbw.command, &cmd_read10, cbw.cmd_len); //-V1086
 
   return tuh_msc_scsi_command(dev_addr, &cbw, buffer, complete_cb, arg);
 }
@@ -269,7 +272,7 @@ bool tuh_msc_write10(uint8_t dev_addr, uint8_t lun, void const* buffer, uint32_t
       .lba         = tu_htonl(lba),
       .block_count = tu_htons(block_count)
   };
-  memcpy(cbw.command, &cmd_write10, cbw.cmd_len);
+  memcpy(cbw.command, &cmd_write10, cbw.cmd_len); //-V1086
 
   return tuh_msc_scsi_command(dev_addr, &cbw, (void*) (uintptr_t) buffer, complete_cb, arg);
 }
@@ -338,8 +341,7 @@ bool msch_xfer_cb(uint8_t dev_addr, uint8_t ep_addr, xfer_result_t event, uint32
         TU_ASSERT(usbh_edpt_xfer(dev_addr, ep_data, p_msc->buffer, (uint16_t) cbw->total_bytes));
         break;
       }
-
-      TU_ATTR_FALLTHROUGH; // fallthrough to status stage
+      TU_ATTR_FALLTHROUGH; // fallthrough to data stage
 
     case MSC_STAGE_DATA:
       // Status stage
@@ -350,20 +352,19 @@ bool msch_xfer_cb(uint8_t dev_addr, uint8_t ep_addr, xfer_result_t event, uint32
     case MSC_STAGE_STATUS:
       // SCSI op is complete
       p_msc->stage = MSC_STAGE_IDLE;
-
-      if (p_msc->complete_cb) {
+      if (p_msc->complete_cb != NULL) {
         tuh_msc_complete_data_t const cb_data = {
             .cbw = cbw,
             .csw = csw,
             .scsi_data = p_msc->buffer,
             .user_arg = p_msc->complete_arg
         };
-        p_msc->complete_cb(dev_addr, &cb_data);
+        (void) p_msc->complete_cb(dev_addr, &cb_data);
       }
       break;
 
-      // unknown state
     default:
+      // unknown state
       break;
   }
 
@@ -501,7 +502,7 @@ static bool config_read_capacity_complete(uint8_t dev_addr, tuh_msc_complete_dat
 
   // Capacity response field: Block size and Last LBA are both Big-Endian
   scsi_read_capacity10_resp_t* resp = (scsi_read_capacity10_resp_t*) (uintptr_t) enum_buf;
-  p_msc->capacity[cbw->lun].block_count = tu_ntohl(resp->last_lba) + 1;
+  p_msc->capacity[cbw->lun].block_count = (uint32_t) (tu_ntohl(resp->last_lba) + 1u);
   p_msc->capacity[cbw->lun].block_size  = tu_ntohl(resp->block_size);
 
   // Mark enumeration is complete
diff --git a/src/class/mtp/mtp.h b/src/class/mtp/mtp.h
new file mode 100644
index 000000000..236cf98e0
--- /dev/null
+++ b/src/class/mtp/mtp.h
@@ -0,0 +1,888 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2025 Ennebi Elettronica (https://ennebielettronica.com)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * This file is part of the TinyUSB stack.
+ */
+
+#ifndef TUSB_MTP_H_
+#define TUSB_MTP_H_
+
+#include "common/tusb_common.h"
+
+#if (CFG_TUD_ENABLED && CFG_TUD_MTP)
+
+#ifdef __cplusplus
+ extern "C" {
+#endif
+
+//--------------------------------------------------------------------+
+// Media Transfer Protocol Class Constant
+//--------------------------------------------------------------------+
+
+// Media Transfer Protocol Subclass
+typedef enum {
+  MTP_SUBCLASS_STILL_IMAGE = 1
+} mtp_subclass_type_t;
+
+// MTP Protocol.
+typedef enum {
+  MTP_PROTOCOL_PIMA_15470 = 1, ///< Picture Transfer Protocol (PIMA 15470)
+} mtp_protocol_type_t;
+
+// PTP/MTP protocol phases
+typedef enum {
+  MTP_PHASE_COMMAND = 0,
+  MTP_PHASE_DATA,
+  MTP_PHASE_RESPONSE,
+  MTP_PHASE_ERROR
+} mtp_phase_type_t;
+
+// PTP/MTP Class requests, PIMA 15740-2000: D.5.2
+typedef enum {
+  MTP_REQ_CANCEL             = 0x64,
+  MTP_REQ_GET_EXT_EVENT_DATA = 0x65,
+  MTP_REQ_RESET              = 0x66,
+  MTP_REQ_GET_DEVICE_STATUS  = 0x67,
+} mtp_class_request_t;
+
+// PTP/MTP Container type
+typedef enum {
+  MTP_CONTAINER_TYPE_UNDEFINED      = 0,
+  MTP_CONTAINER_TYPE_COMMAND_BLOCK  = 1,
+  MTP_CONTAINER_TYPE_DATA_BLOCK     = 2,
+  MTP_CONTAINER_TYPE_RESPONSE_BLOCK = 3,
+  MTP_CONTAINER_TYPE_EVENT_BLOCK    = 4,
+} mtp_container_type_t;
+
+// MTP 1.1 Appendix A: Object formats
+typedef enum {
+  // ---- Base formats ----
+  MTP_OBJ_FORMAT_UNDEFINED        = 0x3000u, // Undefined object
+  MTP_OBJ_FORMAT_ASSOCIATION      = 0x3001u, // Association (for example, a folder)
+  MTP_OBJ_FORMAT_SCRIPT           = 0x3002u, // Device model-specific script
+  MTP_OBJ_FORMAT_EXECUTABLE       = 0x3003u, // Device model-specific binary executable
+  MTP_OBJ_FORMAT_TEXT             = 0x3004u, // Text file
+  MTP_OBJ_FORMAT_HTML             = 0x3005u, // Hypertext Markup Language file (text)
+  MTP_OBJ_FORMAT_DPOF             = 0x3006u, // Digital Print Order Format file (text)
+  MTP_OBJ_FORMAT_AIFF             = 0x3007u, // Audio clip (AIFF)
+  MTP_OBJ_FORMAT_WAV              = 0x3008u, // Audio clip (WAV)
+  MTP_OBJ_FORMAT_MP3              = 0x3009u, // MPEG-1 Layer III audio (ISO/IEC 13818-3)
+  MTP_OBJ_FORMAT_AVI              = 0x300Au, // Video clip (AVI)
+  MTP_OBJ_FORMAT_MPEG             = 0x300Bu, // Video clip (MPEG)
+  MTP_OBJ_FORMAT_ASF              = 0x300Cu, // Microsoft Advanced Streaming Format (video)
+
+  // ---- Image formats ----
+  MTP_OBJ_FORMAT_UNDEFINED_IMAGE  = 0x3800u, // Undefined image object
+  MTP_OBJ_FORMAT_EXIF_JPEG        = 0x3801u, // Exchangeable Image Format, JEIDA standard
+  MTP_OBJ_FORMAT_TIFF_EP          = 0x3802u, // Tag Image File Format for Electronic Photography
+  MTP_OBJ_FORMAT_FLASHPIX         = 0x3803u, // Structured Storage Image Format (FlashPix)
+  MTP_OBJ_FORMAT_BMP              = 0x3804u, // Microsoft Windows Bitmap file
+  MTP_OBJ_FORMAT_CIFF             = 0x3805u, // Canon Camera Image File Format
+  MTP_OBJ_FORMAT_UNDEFINED_3806   = 0x3806u, // Reserved / Undefined
+  MTP_OBJ_FORMAT_GIF              = 0x3807u, // Graphics Interchange Format
+  MTP_OBJ_FORMAT_JFIF             = 0x3808u, // JPEG File Interchange Format
+  MTP_OBJ_FORMAT_CD               = 0x3809u, // PhotoCD Image Pac
+  MTP_OBJ_FORMAT_PICT             = 0x380Au, // Quickdraw Image Format
+  MTP_OBJ_FORMAT_PNG              = 0x380Bu, // Portable Network Graphics
+  MTP_OBJ_FORMAT_UNDEFINED_380C   = 0x380Cu, // Reserved / Undefined
+  MTP_OBJ_FORMAT_TIFF             = 0x380Du, // Tag Image File Format (baseline)
+  MTP_OBJ_FORMAT_TIFF_IT          = 0x380Eu, // Tag Image File Format for IT (graphic arts)
+  MTP_OBJ_FORMAT_JP2              = 0x380Fu, // JPEG2000 Baseline File Format
+  MTP_OBJ_FORMAT_JPX              = 0x3810u, // JPEG2000 Extended File Format
+
+  // ---- Firmware & misc ----
+  MTP_OBJ_FORMAT_UNDEFINED_FIRMWARE = 0xB802u, // Undefined Firmware
+  MTP_OBJ_FORMAT_WBMP               = 0xB803u, // Wireless Application Protocol Bitmap Format (.wbmp)
+  MTP_OBJ_FORMAT_WINDOWS_IMAGE      = 0xB881u, // Windows Image Format
+  MTP_OBJ_FORMAT_JPEGXR             = 0xB804u, // JPEG XR (.hdp, .jxr, .wdp)
+
+  // ---- Audio formats ----
+  MTP_OBJ_FORMAT_UNDEFINED_AUDIO  = 0xB900u, // Undefined audio object
+  MTP_OBJ_FORMAT_WMA              = 0xB901u, // Windows Media Audio
+  MTP_OBJ_FORMAT_OGG              = 0xB902u, // OGG container
+  MTP_OBJ_FORMAT_AAC              = 0xB903u, // Advanced Audio Coding (.aac)
+  MTP_OBJ_FORMAT_AUDIBLE          = 0xB904u, // Audible format
+  MTP_OBJ_FORMAT_FLAC             = 0xB906u, // Free Lossless Audio Codec
+  MTP_OBJ_FORMAT_QCELP            = 0xB907u, // Qualcomm Code Excited Linear Prediction (.qcp)
+  MTP_OBJ_FORMAT_AMR              = 0xB908u, // Adaptive Multi-Rate audio (.amr)
+
+  // ---- Video formats ----
+  MTP_OBJ_FORMAT_UNDEFINED_VIDEO  = 0xB980u, // Undefined video object
+  MTP_OBJ_FORMAT_WMV              = 0xB981u, // Windows Media Video
+  MTP_OBJ_FORMAT_MP4              = 0xB982u, // MP4 Container (ISO 14496-1)
+  MTP_OBJ_FORMAT_MP2              = 0xB983u, // MPEG-1 Layer II audio
+  MTP_OBJ_FORMAT_3GP              = 0xB984u, // 3GP Container
+  MTP_OBJ_FORMAT_3G2              = 0xB985u, // 3GPP2 Container
+  MTP_OBJ_FORMAT_AVCHD            = 0xB986u, // AVCHD (MPEG-4 AVC + Dolby Digital)
+  MTP_OBJ_FORMAT_ATSC_TS          = 0xB987u, // ATSC-compliant MPEG-2 Transport Stream
+  MTP_OBJ_FORMAT_DVB_TS           = 0xB988u, // DVB-compliant MPEG-2 Transport Stream
+
+  // ---- Collections ----
+  MTP_OBJ_FORMAT_UNDEFINED_COLLECTION          = 0xBA00u, // Undefined collection
+  MTP_OBJ_FORMAT_ABSTRACT_MULTIMEDIA_ALBUM     = 0xBA01u, // Abstract Multimedia Album
+  MTP_OBJ_FORMAT_ABSTRACT_IMAGE_ALBUM          = 0xBA02u, // Abstract Image Album
+  MTP_OBJ_FORMAT_ABSTRACT_AUDIO_ALBUM          = 0xBA03u, // Abstract Audio Album
+  MTP_OBJ_FORMAT_ABSTRACT_VIDEO_ALBUM          = 0xBA04u, // Abstract Video Album
+  MTP_OBJ_FORMAT_ABSTRACT_AV_PLAYLIST          = 0xBA05u, // Abstract Audio & Video Playlist
+  MTP_OBJ_FORMAT_ABSTRACT_CONTACT_GROUP        = 0xBA06u, // Abstract Contact Group
+  MTP_OBJ_FORMAT_ABSTRACT_MESSAGE_FOLDER       = 0xBA07u, // Abstract Message Folder
+  MTP_OBJ_FORMAT_ABSTRACT_CHAPTERED_PRODUCTION = 0xBA08u, // Abstract Chaptered Production
+  MTP_OBJ_FORMAT_ABSTRACT_AUDIO_PLAYLIST       = 0xBA09u, // Abstract Audio Playlist
+  MTP_OBJ_FORMAT_ABSTRACT_VIDEO_PLAYLIST       = 0xBA0Au, // Abstract Video Playlist
+  MTP_OBJ_FORMAT_ABSTRACT_MEDIACAST            = 0xBA0Bu, // Abstract Mediacast (RSS enclosure)
+
+  // ---- Playlist formats ----
+  MTP_OBJ_FORMAT_WPL_PLAYLIST     = 0xBA10u, // Windows Media Player Playlist (.wpl)
+  MTP_OBJ_FORMAT_M3U_PLAYLIST     = 0xBA11u, // M3U Playlist
+  MTP_OBJ_FORMAT_MPL_PLAYLIST     = 0xBA12u, // MPL Playlist
+  MTP_OBJ_FORMAT_ASX_PLAYLIST     = 0xBA13u, // ASX Playlist
+  MTP_OBJ_FORMAT_PLS_PLAYLIST     = 0xBA14u, // PLS Playlist
+
+  // ---- Document formats ----
+  MTP_OBJ_FORMAT_UNDEFINED_DOC    = 0xBA80u, // Undefined Document
+  MTP_OBJ_FORMAT_ABSTRACT_DOC     = 0xBA81u, // Abstract Document
+  MTP_OBJ_FORMAT_XML_DOC          = 0xBA82u, // XML Document
+  MTP_OBJ_FORMAT_DOC              = 0xBA83u, // Microsoft Word Document
+  MTP_OBJ_FORMAT_MHT_DOC          = 0xBA84u, // MHT Compiled HTML Document
+  MTP_OBJ_FORMAT_XLS              = 0xBA85u, // Microsoft Excel Spreadsheet
+  MTP_OBJ_FORMAT_PPT              = 0xBA86u, // Microsoft PowerPoint Presentation
+
+  // ---- Messaging ----
+  MTP_OBJ_FORMAT_UNDEFINED_MSG    = 0xBB00u, // Undefined Message
+  MTP_OBJ_FORMAT_ABSTRACT_MSG     = 0xBB01u, // Abstract Message
+
+  // ---- Bookmarks ----
+  MTP_OBJ_FORMAT_UNDEFINED_BOOKMARK = 0xBB10u, // Undefined Bookmark
+  MTP_OBJ_FORMAT_ABSTRACT_BOOKMARK  = 0xBB11u, // Abstract Bookmark
+
+  // ---- Appointments ----
+  MTP_OBJ_FORMAT_UNDEFINED_APPT   = 0xBB20u, // Undefined Appointment
+  MTP_OBJ_FORMAT_ABSTRACT_APPT    = 0xBB21u, // Abstract Appointment
+  MTP_OBJ_FORMAT_VCALENDAR1       = 0xBB22u, // vCalendar 1.0
+
+  // ---- Tasks ----
+  MTP_OBJ_FORMAT_UNDEFINED_TASK   = 0xBB40u, // Undefined Task
+  MTP_OBJ_FORMAT_ABSTRACT_TASK    = 0xBB41u, // Abstract Task
+  MTP_OBJ_FORMAT_ICALENDAR        = 0xBB42u, // iCalendar
+
+  // ---- Notes ----
+  MTP_OBJ_FORMAT_UNDEFINED_NOTE   = 0xBB60u, // Undefined Note
+  MTP_OBJ_FORMAT_ABSTRACT_NOTE    = 0xBB61u, // Abstract Note
+
+  // ---- Contacts ----
+  MTP_OBJ_FORMAT_UNDEFINED_CONTACT= 0xBB80u, // Undefined Contact
+  MTP_OBJ_FORMAT_ABSTRACT_CONTACT = 0xBB81u, // Abstract Contact
+  MTP_OBJ_FORMAT_VCARD2           = 0xBB82u, // vCard 2.1
+  MTP_OBJ_FORMAT_VCARD3           = 0xBB83u, // vCard 3.0
+} mtp_object_formats_t;
+
+// MTP 1.1 Appendix B: Object Properties
+typedef enum {
+  MTP_OBJ_PROP_STORAGE_ID                 = 0xDC01u, // StorageID
+  MTP_OBJ_PROP_OBJECT_FORMAT              = 0xDC02u, // Object Format
+  MTP_OBJ_PROP_PROTECTION_STATUS          = 0xDC03u, // Protection Status
+  MTP_OBJ_PROP_OBJECT_SIZE                = 0xDC04u, // Object Size
+  MTP_OBJ_PROP_ASSOCIATION_TYPE           = 0xDC05u, // Association Type
+  MTP_OBJ_PROP_ASSOCIATION_DESC           = 0xDC06u, // Association Description
+  MTP_OBJ_PROP_OBJECT_FILE_NAME           = 0xDC07u, // Object File Name
+  MTP_OBJ_PROP_DATE_CREATED               = 0xDC08u, // Date Created
+  MTP_OBJ_PROP_DATE_MODIFIED              = 0xDC09u, // Date Modified
+  MTP_OBJ_PROP_KEYWORDS                   = 0xDC0Au, // Keywords
+  MTP_OBJ_PROP_PARENT_OBJECT              = 0xDC0Bu, // Parent Object
+  MTP_OBJ_PROP_ALLOWED_FOLDER_CONTENTS    = 0xDC0Cu, // Allowed Folder Contents
+  MTP_OBJ_PROP_HIDDEN                     = 0xDC0Du, // Hidden
+  MTP_OBJ_PROP_SYSTEM_OBJECT              = 0xDC0Eu, // System Object
+  // 0xDC0F-0xDC40 is reserved
+
+  MTP_OBJ_PROP_PERSISTENT_UID             = 0xDC41u, // Persistent Unique Object Identifier
+  MTP_OBJ_PROP_SYNC_ID                    = 0xDC42u, // SyncID
+  MTP_OBJ_PROP_PROPERTY_BAG               = 0xDC43u, // Property Bag
+  MTP_OBJ_PROP_NAME                       = 0xDC44u, // Name
+  MTP_OBJ_PROP_CREATED_BY                 = 0xDC45u, // Created By
+  MTP_OBJ_PROP_ARTIST                     = 0xDC46u, // Artist
+  MTP_OBJ_PROP_DATE_AUTHORED              = 0xDC47u, // Date Authored
+  MTP_OBJ_PROP_DESCRIPTION                = 0xDC48u, // Description
+  MTP_OBJ_PROP_URL_REFERENCE              = 0xDC49u, // URL Reference
+  MTP_OBJ_PROP_LANGUAGE_LOCALE            = 0xDC4Au, // Language-Locale
+  MTP_OBJ_PROP_COPYRIGHT_INFO             = 0xDC4Bu, // Copyright Information
+  MTP_OBJ_PROP_SOURCE                     = 0xDC4Cu, // Source
+  MTP_OBJ_PROP_ORIGIN_LOCATION            = 0xDC4Du, // Origin Location
+  MTP_OBJ_PROP_DATE_ADDED                 = 0xDC4Eu, // Date Added
+  MTP_OBJ_PROP_NON_CONSUMABLE             = 0xDC4Fu, // Non-Consumable
+  MTP_OBJ_PROP_CORRUPT_UNPLAYABLE         = 0xDC50u, // Corrupt/Unplayable
+  MTP_OBJ_PROP_PRODUCER_SERIAL_NUMBER     = 0xDC51u, // ProducerSerialNumber
+  // 0xDC52-0xDC80 is reserved
+
+  MTP_OBJ_PROP_REP_SAMPLE_FORMAT          = 0xDC81u, // Representative Sample Format
+  MTP_OBJ_PROP_REP_SAMPLE_SIZE            = 0xDC82u, // Representative Sample Size
+  MTP_OBJ_PROP_REP_SAMPLE_HEIGHT          = 0xDC83u, // Representative Sample Height
+  MTP_OBJ_PROP_REP_SAMPLE_WIDTH           = 0xDC84u, // Representative Sample Width
+  MTP_OBJ_PROP_REP_SAMPLE_DURATION        = 0xDC85u, // Representative Sample Duration
+  MTP_OBJ_PROP_REP_SAMPLE_DATA            = 0xDC86u, // Representative Sample Data
+  MTP_OBJ_PROP_WIDTH                      = 0xDC87u, // Width
+  MTP_OBJ_PROP_HEIGHT                     = 0xDC88u, // Height
+  MTP_OBJ_PROP_DURATION                   = 0xDC89u, // Duration
+  MTP_OBJ_PROP_RATING                     = 0xDC8Au, // Rating
+  MTP_OBJ_PROP_TRACK                      = 0xDC8Bu, // Track
+  MTP_OBJ_PROP_GENRE                      = 0xDC8Cu, // Genre
+  MTP_OBJ_PROP_CREDITS                    = 0xDC8Du, // Credits
+  MTP_OBJ_PROP_LYRICS                     = 0xDC8Eu, // Lyrics
+  MTP_OBJ_PROP_SUBSCRIPTION_CONTENT_ID    = 0xDC8Fu, // Subscription Content ID
+  MTP_OBJ_PROP_PRODUCED_BY                = 0xDC90u, // Produced By
+  MTP_OBJ_PROP_USE_COUNT                  = 0xDC91u, // Use Count
+  MTP_OBJ_PROP_SKIP_COUNT                 = 0xDC92u, // Skip Count
+  MTP_OBJ_PROP_LAST_ACCESSED              = 0xDC93u, // Last Accessed
+  MTP_OBJ_PROP_PARENTAL_RATING            = 0xDC94u, // Parental Rating
+  MTP_OBJ_PROP_META_GENRE                 = 0xDC95u, // Meta Genre
+  MTP_OBJ_PROP_COMPOSER                   = 0xDC96u, // Composer
+  MTP_OBJ_PROP_EFFECTIVE_RATING           = 0xDC97u, // Effective Rating
+  MTP_OBJ_PROP_SUBTITLE                   = 0xDC98u, // Subtitle
+  MTP_OBJ_PROP_ORIGINAL_RELEASE_DATE      = 0xDC99u, // Original Release Date
+  MTP_OBJ_PROP_ALBUM_NAME                 = 0xDC9Au, // Album Name
+  MTP_OBJ_PROP_ALBUM_ARTIST               = 0xDC9Bu, // Album Artist
+  MTP_OBJ_PROP_MOOD                       = 0xDC9Cu, // Mood
+  MTP_OBJ_PROP_DRM_STATUS                 = 0xDC9Du, // DRM Status
+  MTP_OBJ_PROP_SUB_DESCRIPTION            = 0xDC9Eu, // Sub Description
+  // 0xDC9F-0xDCD0 is reserved
+
+  MTP_OBJ_PROP_IS_CROPPED                 = 0xDCD1u, // Is Cropped
+  MTP_OBJ_PROP_IS_COLOUR_CORRECTED        = 0xDCD2u, // Is Colour Corrected
+  MTP_OBJ_PROP_IMAGE_BIT_DEPTH            = 0xDCD3u, // Image Bit Depth
+  MTP_OBJ_PROP_FNUMBER                    = 0xDCD4u, // Fnumber (aperture ×100)
+  MTP_OBJ_PROP_EXPOSURE_TIME              = 0xDCD5u, // Exposure Time (sec ×10,000)
+  MTP_OBJ_PROP_EXPOSURE_INDEX             = 0xDCD6u, // Exposure Index (ISO)
+  // 0xDCD7-0xDCDF is reserved
+
+  MTP_OBJ_PROP_DISPLAY_NAME               = 0xDCE0u, // Display Name
+  MTP_OBJ_PROP_BODY_TEXT                  = 0xDCE1u, // Body Text
+  MTP_OBJ_PROP_SUBJECT                    = 0xDCE2u, // Subject
+  MTP_OBJ_PROP_PRIORITY                   = 0xDCE3u, // Priority
+  // 0xDCE4-0xDCFF is reserved
+
+  MTP_OBJ_PROP_GIVEN_NAME                 = 0xDD00u, // Given Name
+  MTP_OBJ_PROP_MIDDLE_NAMES               = 0xDD01u, // Middle Names
+  MTP_OBJ_PROP_FAMILY_NAME                = 0xDD02u, // Family Name
+  MTP_OBJ_PROP_PREFIX                     = 0xDD03u, // Prefix
+  MTP_OBJ_PROP_SUFFIX                     = 0xDD04u, // Suffix
+  MTP_OBJ_PROP_PHONETIC_GIVEN_NAME        = 0xDD05u, // Phonetic Given Name
+  MTP_OBJ_PROP_PHONETIC_FAMILY_NAME       = 0xDD06u, // Phonetic Family Name
+  MTP_OBJ_PROP_EMAIL_PRIMARY              = 0xDD07u, // Email Primary
+  MTP_OBJ_PROP_EMAIL_PERSONAL_1           = 0xDD08u, // Email Personal 1
+  MTP_OBJ_PROP_EMAIL_PERSONAL_2           = 0xDD09u, // Email Personal 2
+  MTP_OBJ_PROP_EMAIL_BUSINESS_1           = 0xDD0Au, // Email Business 1
+  MTP_OBJ_PROP_EMAIL_BUSINESS_2           = 0xDD0Bu, // Email Business 2
+  MTP_OBJ_PROP_EMAIL_OTHERS               = 0xDD0Cu, // Email Others
+  MTP_OBJ_PROP_PHONE_PRIMARY              = 0xDD0Du, // Phone Number Primary
+  MTP_OBJ_PROP_PHONE_PERSONAL_1           = 0xDD0Eu, // Phone Number Personal
+  MTP_OBJ_PROP_PHONE_PERSONAL_2           = 0xDD0Fu, // Phone Number Personal 2
+  MTP_OBJ_PROP_PHONE_BUSINESS_1           = 0xDD10u, // Phone Number Business
+  MTP_OBJ_PROP_PHONE_BUSINESS_2           = 0xDD11u, // Phone Number Business 2
+  MTP_OBJ_PROP_PHONE_MOBILE_1             = 0xDD12u, // Phone Number Mobile
+  MTP_OBJ_PROP_PHONE_MOBILE_2             = 0xDD13u, // Phone Number Mobile 2
+  MTP_OBJ_PROP_FAX_PRIMARY                = 0xDD14u, // Fax Number Primary
+  MTP_OBJ_PROP_FAX_PERSONAL               = 0xDD15u, // Fax Number Personal
+  MTP_OBJ_PROP_FAX_BUSINESS               = 0xDD16u, // Fax Number Business
+  MTP_OBJ_PROP_PAGER_NUMBER               = 0xDD17u, // Pager Number
+  MTP_OBJ_PROP_PHONE_OTHERS               = 0xDD18u, // Phone Number Others
+  MTP_OBJ_PROP_WEB_PRIMARY                = 0xDD19u, // Primary Web Address
+  MTP_OBJ_PROP_WEB_PERSONAL               = 0xDD1Au, // Personal Web Address
+  MTP_OBJ_PROP_WEB_BUSINESS               = 0xDD1Bu, // Business Web Address
+  MTP_OBJ_PROP_IM_ADDRESS_1               = 0xDD1Cu, // Instant Messenger Address
+  MTP_OBJ_PROP_IM_ADDRESS_2               = 0xDD1Du, // Instant Messenger Address 2
+  MTP_OBJ_PROP_IM_ADDRESS_3               = 0xDD1Eu, // Instant Messenger Address 3
+  MTP_OBJ_PROP_ADDR_PERSONAL_FULL         = 0xDD1Fu, // Postal Address Personal Full
+  MTP_OBJ_PROP_ADDR_PERSONAL_LINE1        = 0xDD20u, // Postal Address Personal Line 1
+  MTP_OBJ_PROP_ADDR_PERSONAL_LINE2        = 0xDD21u, // Postal Address Personal Line 2
+  MTP_OBJ_PROP_ADDR_PERSONAL_CITY         = 0xDD22u, // Postal Address Personal City
+  MTP_OBJ_PROP_ADDR_PERSONAL_REGION       = 0xDD23u, // Postal Address Personal Region
+  MTP_OBJ_PROP_ADDR_PERSONAL_POSTAL_CODE  = 0xDD24u, // Postal Address Personal Postal Code
+  MTP_OBJ_PROP_ADDR_PERSONAL_COUNTRY      = 0xDD25u, // Postal Address Personal Country
+  MTP_OBJ_PROP_ADDR_BUSINESS_FULL         = 0xDD26u, // Postal Address Business Full
+  MTP_OBJ_PROP_ADDR_BUSINESS_LINE1        = 0xDD27u, // Postal Address Business Line 1
+  MTP_OBJ_PROP_ADDR_BUSINESS_LINE2        = 0xDD28u, // Postal Address Business Line 2
+  MTP_OBJ_PROP_ADDR_BUSINESS_CITY         = 0xDD29u, // Postal Address Business City
+  MTP_OBJ_PROP_ADDR_BUSINESS_REGION       = 0xDD2Au, // Postal Address Business Region
+  MTP_OBJ_PROP_ADDR_BUSINESS_POSTAL_CODE  = 0xDD2Bu, // Postal Address Business Postal Code
+  MTP_OBJ_PROP_ADDR_BUSINESS_COUNTRY      = 0xDD2Cu, // Postal Address Business Country
+  MTP_OBJ_PROP_ADDR_OTHER_FULL            = 0xDD2Du, // Postal Address Other Full
+  MTP_OBJ_PROP_ADDR_OTHER_LINE1           = 0xDD2Eu, // Postal Address Other Line 1
+  MTP_OBJ_PROP_ADDR_OTHER_LINE2           = 0xDD2Fu, // Postal Address Other Line 2
+  MTP_OBJ_PROP_ADDR_OTHER_CITY            = 0xDD30u, // Postal Address Other City
+  MTP_OBJ_PROP_ADDR_OTHER_REGION          = 0xDD31u, // Postal Address Other Region
+  MTP_OBJ_PROP_ADDR_OTHER_POSTAL_CODE     = 0xDD32u, // Postal Address Other Postal Code
+  MTP_OBJ_PROP_ADDR_OTHER_COUNTRY         = 0xDD33u, // Postal Address Other Country
+  MTP_OBJ_PROP_ORGANIZATION_NAME          = 0xDD34u, // Organization Name
+  MTP_OBJ_PROP_PHONETIC_ORG_NAME          = 0xDD35u, // Phonetic Organization Name
+  MTP_OBJ_PROP_ROLE                       = 0xDD36u, // Role
+  MTP_OBJ_PROP_BIRTHDATE                  = 0xDD37u, // Birthdate
+  // 0xDD38-0xDD3F is reserved
+
+  MTP_OBJ_PROP_MESSAGE_TO                 = 0xDD40u, // Message To
+  MTP_OBJ_PROP_MESSAGE_CC                 = 0xDD41u, // Message CC
+  MTP_OBJ_PROP_MESSAGE_BCC                = 0xDD42u, // Message BCC
+  MTP_OBJ_PROP_MESSAGE_READ               = 0xDD43u, // Message Read
+  MTP_OBJ_PROP_MESSAGE_RECEIVED_TIME      = 0xDD44u, // Message Received Time
+  MTP_OBJ_PROP_MESSAGE_SENDER             = 0xDD45u, // Message Sender
+  // 0xDD46-0xDD4F is reserved
+
+  MTP_OBJ_PROP_ACTIVITY_BEGIN_TIME        = 0xDD50u, // Activity Begin Time
+  MTP_OBJ_PROP_ACTIVITY_END_TIME          = 0xDD51u, // Activity End Time
+  MTP_OBJ_PROP_ACTIVITY_LOCATION          = 0xDD52u, // Activity Location
+  // 0xDD53 is reserved
+  MTP_OBJ_PROP_ACTIVITY_REQUIRED_ATTENDEES= 0xDD54u, // Activity Required Attendees
+  MTP_OBJ_PROP_ACTIVITY_OPTIONAL_ATTENDEES= 0xDD55u, // Activity Optional Attendees
+  MTP_OBJ_PROP_ACTIVITY_RESOURCES         = 0xDD56u, // Activity Resources
+  MTP_OBJ_PROP_ACTIVITY_ACCEPTED          = 0xDD57u, // Activity Accepted
+  MTP_OBJ_PROP_ACTIVITY_TENTATIVE         = 0xDD58u, // Activity Tentative
+  MTP_OBJ_PROP_ACTIVITY_DECLINED          = 0xDD59u, // Activity Declined
+  MTP_OBJ_PROP_ACTIVITY_REMINDER_TIME     = 0xDD5Au, // Activity Reminder Time
+  MTP_OBJ_PROP_ACTIVITY_OWNER             = 0xDD5Bu, // Activity Owner
+  MTP_OBJ_PROP_ACTIVITY_STATUS            = 0xDD5Cu, // Activity Status
+  MTP_OBJ_PROP_OWNER                      = 0xDD5Du, // Owner
+  MTP_OBJ_PROP_EDITOR                     = 0xDD5Eu, // Editor
+  MTP_OBJ_PROP_WEBMASTER                  = 0xDD5Fu, // Webmaster
+
+  MTP_OBJ_PROP_URL_SOURCE                 = 0xDD60u, // URL Source
+  MTP_OBJ_PROP_URL_DESTINATION            = 0xDD61u, // URL Destination
+  MTP_OBJ_PROP_TIME_BOOKMARK              = 0xDD62u, // Time Bookmark
+  MTP_OBJ_PROP_OBJECT_BOOKMARK            = 0xDD63u, // Object Bookmark
+  MTP_OBJ_PROP_BYTE_BOOKMARK              = 0xDD64u, // Byte Bookmark
+  // 0xDD65-0xDD6F is reserved
+
+  MTP_OBJ_PROP_LAST_BUILD_DATE            = 0xDD70u, // Last Build Date
+  MTP_OBJ_PROP_TIME_TO_LIVE               = 0xDD71u, // Time to Live (minutes)
+  MTP_OBJ_PROP_MEDIA_GUID                 = 0xDD72u, // Media GUID
+  // 0xDD73-0xDDFF is reserved
+
+  // media encoding
+  MTP_OBJ_PROP_TOTAL_BITRATE              = 0xDE91u, // Total BitRate
+  MTP_OBJ_PROP_BITRATE_TYPE               = 0xDE92u, // Bitrate Type
+  MTP_OBJ_PROP_SAMPLE_RATE                = 0xDE93u, // Sample Rate
+  MTP_OBJ_PROP_NUM_CHANNELS               = 0xDE94u, // Number Of Channels
+  MTP_OBJ_PROP_AUDIO_BITDEPTH             = 0xDE95u, // Audio BitDepth
+  // 0xDE96 is reserved
+  MTP_OBJ_PROP_SCAN_TYPE                  = 0xDE97u, // Scan Type
+  // 0xDE98 is reserved
+  MTP_OBJ_PROP_AUDIO_WAVE_CODEC           = 0xDE99u, // Audio WAVE Codec
+  MTP_OBJ_PROP_AUDIO_BITRATE              = 0xDE9Au, // Audio BitRate
+  MTP_OBJ_PROP_VIDEO_FOURCC_CODEC         = 0xDE9Bu, // Video FourCC Codec
+  MTP_OBJ_PROP_VIDEO_BITRATE              = 0xDE9Cu, // Video BitRate
+  MTP_OBJ_PROP_FRAMES_PER_KSEC            = 0xDE9Du, // Frames Per Thousand Seconds
+  MTP_OBJ_PROP_KEYFRAME_DISTANCE          = 0xDE9Eu, // KeyFrame Distance (ms)
+  MTP_OBJ_PROP_BUFFER_SIZE                = 0xDE9Fu, // Buffer Size
+  MTP_OBJ_PROP_ENCODING_QUALITY           = 0xDEA0u, // Encoding Quality
+  MTP_OBJ_PROP_ENCODING_PROFILE           = 0xDEA1u  // Encoding Profile
+} mtp_object_properties_t;
+
+
+// MTP 1.1 Appendeix C: Device Properties
+typedef enum {
+  MTP_DEV_PROP_UNDEFINED                      = 0x5000u,
+  MTP_DEV_PROP_BATTERY_LEVEL                  = 0x5001u,
+  MTP_DEV_PROP_FUNCTIONAL_MODE                = 0x5002u,
+  MTP_DEV_PROP_IMAGE_SIZE                     = 0x5003u,
+  MTP_DEV_PROP_COMPRESSION_SETTING            = 0x5004u,
+  MTP_DEV_PROP_WHITE_BALANCE                  = 0x5005u,
+  MTP_DEV_PROP_RGB_GAIN                       = 0x5006u,
+  MTP_DEV_PROP_F_NUMBER                       = 0x5007u,
+  MTP_DEV_PROP_FOCAL_LENGTH                   = 0x5008u,
+  MTP_DEV_PROP_FOCUS_DISTANCE                 = 0x5009u,
+  MTP_DEV_PROP_FOCUS_MODE                     = 0x500Au,
+  MTP_DEV_PROP_EXPOSURE_METERING_MODE         = 0x500Bu,
+  MTP_DEV_PROP_FLASH_MODE                     = 0x500Cu,
+  MTP_DEV_PROP_EXPOSURE_TIME                  = 0x500Du,
+  MTP_DEV_PROP_EXPOSURE_PROGRAM_MODE          = 0x500Eu,
+  MTP_DEV_PROP_EXPOSURE_INDEX                 = 0x500Fu,
+  MTP_DEV_PROP_EXPOSURE_BIAS_COMPENSATION     = 0x5010u,
+  MTP_DEV_PROP_DATE_TIME                      = 0x5011u,
+  MTP_DEV_PROP_CAPTURE_DELAY                  = 0x5012u,
+  MTP_DEV_PROP_STILL_CAPTURE_MODE             = 0x5013u,
+  MTP_DEV_PROP_CONTRAST                       = 0x5014u,
+  MTP_DEV_PROP_SHARPNESS                      = 0x5015u,
+  MTP_DEV_PROP_DIGITAL_ZOOM                   = 0x5016u,
+  MTP_DEV_PROP_EFFECT_MODE                    = 0x5017u,
+  MTP_DEV_PROP_BURST_NUMBER                   = 0x5018u,
+  MTP_DEV_PROP_BURST_INTERVAL                 = 0x5019u,
+  MTP_DEV_PROP_TIMELAPSE_NUMBER               = 0x501Au,
+  MTP_DEV_PROP_TIMELAPSE_INTERVAL             = 0x501Bu,
+  MTP_DEV_PROP_FOCUS_METERING_MODE            = 0x501Cu,
+  MTP_DEV_PROP_UPLOAD_URL                     = 0x501Du,
+  MTP_DEV_PROP_ARTIST                         = 0x501Eu,
+  MTP_DEV_PROP_COPYRIGHT_INFO                 = 0x501Fu,
+  MTP_DEV_PROP_SYNCHRONIZTION_PARTNER         = 0xD401,
+  MTP_DEV_PROP_DEVICE_FRIENDLY_NAME           = 0xD402u,
+  MTP_DEV_PROP_VOLUME                         = 0xD403u,
+  MTP_DEV_PROP_SUPPORTED_FORMATS_ORDERED      = 0xD404u,
+  MTP_DEV_PROP_DEVICE_ICON                    = 0xD405u,
+  MTP_DEV_PROP_SECTION_INITIATOR_VERSION_INFO = 0xD406u,
+  MTP_DEV_PROP_PERCEIVED_DEVICE_TYPE          = 0xD407u,
+  MTP_DEV_PROP_PLAYBACK_RATE                  = 0xD410u,
+  MTP_DEV_PROP_PLAYBACK_OBJECT                = 0xD411u,
+  MTP_DEV_PROP_PLAYBACK_CONTAINER_INDEX       = 0xD412u,
+} mtp_event_properties_t;
+
+// MTP 1.1 Appendix D: Operations
+typedef enum {
+  MTP_OP_UNDEFINED                  = 0x1000u,
+  MTP_OP_GET_DEVICE_INFO            = 0x1001u,
+  MTP_OP_OPEN_SESSION               = 0x1002u,
+  MTP_OP_CLOSE_SESSION              = 0x1003u,
+  MTP_OP_GET_STORAGE_IDS            = 0x1004u,
+  MTP_OP_GET_STORAGE_INFO           = 0x1005u,
+  MTP_OP_GET_NUM_OBJECTS            = 0x1006u,
+  MTP_OP_GET_OBJECT_HANDLES         = 0x1007u,
+  MTP_OP_GET_OBJECT_INFO            = 0x1008u,
+  MTP_OP_GET_OBJECT                 = 0x1009u,
+  MTP_OP_GET_THUMB                  = 0x100Au,
+  MTP_OP_DELETE_OBJECT              = 0x100Bu,
+  MTP_OP_SEND_OBJECT_INFO           = 0x100Cu,
+  MTP_OP_SEND_OBJECT                = 0x100Du,
+  MTP_OP_INITIATE_CAPTURE           = 0x100Eu,
+  MTP_OP_FORMAT_STORE               = 0x100Fu,
+  MTP_OP_RESET_DEVICE               = 0x1010u,
+  MTP_OP_SELF_TEST                  = 0x1011u,
+  MTP_OP_SET_OBJECT_PROTECTION      = 0x1012u,
+  MTP_OP_POWER_DOWN                 = 0x1013u,
+  MTP_OP_GET_DEVICE_PROP_DESC       = 0x1014u,
+  MTP_OP_GET_DEVICE_PROP_VALUE      = 0x1015u,
+  MTP_OP_SET_DEVICE_PROP_VALUE      = 0x1016u,
+  MTP_OP_RESET_DEVICE_PROP_VALUE    = 0x1017u,
+  MTP_OP_TERMINATE_OPEN_CAPTURE     = 0x1018u,
+  MTP_OP_MOVE_OBJECT                = 0x1019u,
+  MTP_OP_COPY_OBJECT                = 0x101Au,
+  MTP_OP_GET_PARTIAL_OBJECT         = 0x101Bu,
+  MTP_OP_INITIATE_OPEN_CAPTURE      = 0x101Bu,
+  MTP_OP_GET_OBJECT_PROPS_SUPPORTED = 0x9801u,
+  MTP_OP_GET_OBJECT_PROP_DESC       = 0x9802u,
+  MTP_OP_GET_OBJECT_PROP_VALUE      = 0x9803u,
+  MTP_OP_SET_OBJECT_PROP_VALUE      = 0x9804u,
+  MTP_OP_GET_OBJECT_PROPLIST        = 0x9805u,
+  MTP_OP_GET_OBJECT_PROP_REFERENCES = 0x9810u,
+
+  MTP_OP_GET_SERVICE_IDS            = 0x9301u,
+  MTP_OP_GET_SERVICE_INFO           = 0x9302u,
+  MTP_OP_GET_SERVICE_CAPABILITIES   = 0x9303u,
+  MTP_OP_GET_SERVICE_PROP_DESC      = 0x9304u,
+
+  // Appendix E: Enhanced Operations
+  MTP_OP_GET_OBJECT_PROP_LIST         = 0x9805u,
+  MTP_OP_SET_OBJECT_PROP_LIST         = 0x9806u,
+  MTP_OP_GET_INTERDEPENDENT_PROP_DESC = 0x9807u,
+  MTP_OP_SEND_OBJECT_PROP_LIST        = 0x9808u,
+} mtp_operation_code_t;
+
+// Appendix F: Responses
+typedef enum {
+  MTP_RESP_UNDEFINED                           = 0x2000u,
+  MTP_RESP_OK                                  = 0x2001u,
+  MTP_RESP_GENERAL_ERROR                       = 0x2002u,
+  MTP_RESP_SESSION_NOT_OPEN                    = 0x2003u,
+  MTP_RESP_INVALID_TRANSACTION_ID              = 0x2004u,
+  MTP_RESP_OPERATION_NOT_SUPPORTED             = 0x2005u,
+  MTP_RESP_PARAMETER_NOT_SUPPORTED             = 0x2006u,
+  MTP_RESP_INCOMPLETE_TRANSFER                 = 0x2007u,
+  MTP_RESP_INVALID_STORAGE_ID                  = 0x2008u,
+  MTP_RESP_INVALID_OBJECT_HANDLE               = 0x2009u,
+  MTP_RESP_DEVICE_PROP_NOT_SUPPORTED           = 0x200Au,
+  MTP_RESP_INVALID_OBJECT_FORMAT_CODE          = 0x200Bu,
+  MTP_RESP_STORE_FULL                          = 0x200Cu,
+  MTP_RESP_OBJECT_WRITE_PROTECTED              = 0x200Du,
+  MPT_RESC_STORE_READ_ONLY                     = 0x200Eu,
+  MTP_RESP_ACCESS_DENIED                       = 0x200Fu,
+  MTP_RESP_NO_THUMBNAIL_PRESENT                = 0x2010u,
+  MTP_RESP_SELF_TEST_FAILED                    = 0x2011u,
+  MTP_RESP_PARTIAL_DELETION                    = 0x2012u,
+  MTP_RESP_STORE_NOT_AVAILABLE                 = 0x2013u,
+  MTP_RESP_SPECIFICATION_BY_FORMAT_UNSUPPORTED = 0x2014u,
+  MTP_RESP_NO_VALID_OBJECTINFO                 = 0x2015u,
+  MTP_RESP_INVALID_CODE_FORMAT                 = 0x2016u,
+  MTP_RESP_UNKNOWN_VENDOR_CODE                 = 0x2017u,
+  MTP_RESP_CAPTURE_ALREADY_TERMINATED          = 0x2018u,
+  MTP_RESP_DEVICE_BUSY                         = 0x2019u,
+  MTP_RESP_INVALID_PARENT_OBJECT               = 0x201Au,
+  MTP_RESP_INVALID_DEVICE_PROP_FORMAT          = 0x201Bu,
+  MTP_RESP_INVALID_DEVICE_PROP_VALUE           = 0x201Cu,
+  MTP_RESP_INVALID_PARAMETER                   = 0x201Du,
+  MTP_RESP_SESSION_ALREADY_OPEN                = 0x201Eu,
+  MTP_RESP_TRANSACTION_CANCELLED               = 0x201Fu,
+  MTP_RESP_SPEC_OF_DESTINATION_UNSUPPORTED     = 0x2020u,
+
+  MTP_RESP_INVALID_OBJECT_PROP_CODE            = 0xA801u,
+  MTP_RESP_INVALID_OBJECT_PROP_FORMAT          = 0xA802u,
+  MTP_RESP_INVALID_OBJECT_PROP_VALUE           = 0xA803u,
+  MTP_RESP_INVALID_OBJECT_REFERENCE            = 0xA804u,
+  MTP_RESP_GROUP_NOT_SUPPORTED                 = 0xA805u,
+  MTP_RESP_INVALID_DATASET                     = 0xA806u,
+  MTP_RESP_SPEC_BY_GROUP_UNSUPPORTED           = 0xA807u,
+  MTP_RESP_SPEC_BY_DEPTH_UNSUPPORTED           = 0xA808u,
+  MTP_RESP_OBJECT_TOO_LARGE                    = 0xA809u,
+  MTP_RESP_OBJECT_PROP_NOT_SUPPORTED           = 0xA80Au,
+} mtp_response_t;
+
+// Appendix G: Events
+typedef enum {
+  MTP_EVENT_UNDEFINED                 = 0x4000,
+  MTP_EVENT_CANCEL_TRANSACTION        = 0x4001,
+  MTP_EVENT_OBJECT_ADDED              = 0x4002,
+  MTP_EVENT_OBJECT_REMOVED            = 0x4003,
+  MTP_EVENT_STORE_ADDED               = 0x4004,
+  MTP_EVENT_STORE_REMOVED             = 0x4005,
+  MTP_EVENT_DEVICE_PROP_CHANGED       = 0x4006,
+  MTP_EVENT_OBJECT_INFO_CHANGED       = 0x4007,
+  MTP_EVENT_DEVICE_INFO_CHANGED       = 0x4008,
+  MTP_EVENT_REQUEST_OBJECT_TRANSFER   = 0x4009,
+  MTP_EVENT_STORE_FULL                = 0x400Au,
+  MTP_EVENT_DEVICE_RESET              = 0x400Bu,
+  MTP_EVENT_STORAGE_INFO_CHANGED      = 0x400Cu,
+  MTP_EVENT_CAPTURE_COMPLETE          = 0x400Du,
+  MTP_EVENT_UNREPORTED_STATUS         = 0x400Eu,
+  MTP_EVENT_OBJECT_PROP_CHANGED       = 0xC801u,
+  MTP_EVENT_OBJECT_PROP_DESC_CHANGED  = 0xC802u,
+  MTP_EVENT_OBJECT_REFERENCES_CHANGED = 0xC803u,
+} mtp_event_code_t;
+
+// Datatypes
+typedef enum {
+  MTP_DATA_TYPE_UNDEFINED = 0x0000u,
+  // scalars
+  MTP_DATA_TYPE_INT8      = 0x0001u,
+  MTP_DATA_TYPE_UINT8     = 0x0002u,
+  MTP_DATA_TYPE_INT16     = 0x0003u,
+  MTP_DATA_TYPE_UINT16    = 0x0004u,
+  MTP_DATA_TYPE_INT32     = 0x0005u,
+  MTP_DATA_TYPE_UINT32    = 0x0006u,
+  MTP_DATA_TYPE_INT64     = 0x0007u,
+  MTP_DATA_TYPE_UINT64    = 0x0008u,
+  MTP_DATA_TYPE_INT128    = 0x0009u,
+  MTP_DATA_TYPE_UINT128   = 0x000Au,
+  // array
+  MTP_DATA_TYPE_AINT8     = 0x4001u,
+  MTP_DATA_TYPE_AUINT8    = 0x4002u,
+  MTP_DATA_TYPE_AINT16    = 0x4003u,
+  MTP_DATA_TYPE_AUINT16   = 0x4004u,
+  MTP_DATA_TYPE_AINT32    = 0x4005u,
+  MTP_DATA_TYPE_AUINT32   = 0x4006u,
+  MTP_DATA_TYPE_AINT64    = 0x4007u,
+  MTP_DATA_TYPE_AUINT64   = 0x4008u,
+  MTP_DATA_TYPE_AINT128   = 0x4009u,
+  MTP_DATA_TYPE_AUINT128  = 0x400Au,
+  MTP_DATA_TYPE_STR       = 0xFFFFu,
+} mtp_data_type_t;
+
+// Get/Set
+typedef enum {
+  MTP_MODE_GET     = 0x00u,
+  MTP_MODE_GET_SET = 0x01u,
+} mtp_mode_get_set_t;
+
+typedef enum {
+  MTP_STORAGE_TYPE_UNDEFINED     = 0x0000u,
+  MTP_STORAGE_TYPE_FIXED_ROM     = 0x0001u,
+  MTP_STORAGE_TYPE_REMOVABLE_ROM = 0x0002u,
+  MTP_STORAGE_TYPE_FIXED_RAM     = 0x0003u,
+  MTP_STORAGE_TYPE_REMOVABLE_RAM = 0x0004u,
+} mtp_storage_type_t;
+
+typedef enum {
+  MTP_FILESYSTEM_TYPE_UNDEFINED            = 0x0000u,
+  MTP_FILESYSTEM_TYPE_GENERIC_FLAT         = 0x0001u,
+  MTP_FILESYSTEM_TYPE_GENERIC_HIERARCHICAL = 0x0002u,
+  MTP_FILESYSTEM_TYPE_DCF                  = 0x0003u,
+} mtp_filesystem_type_t;
+
+typedef enum {
+  MTP_ACCESS_CAPABILITY_READ_WRITE                        = 0x0000u,
+  MTP_ACCESS_CAPABILITY_READ_ONLY_WITHOUT_OBJECT_DELETION = 0x0001u,
+  MTP_ACCESS_CAPABILITY_READ_ONLY_WITH_OBJECT_DELETION    = 0x0002u,
+} mtp_access_capability_t;
+
+typedef enum {
+  MTP_PROTECTION_STATUS_NO_PROTECTION  = 0x0000u,
+  MTP_PROTECTION_STATUS_READ_ONLY      = 0x0001u,
+  MTP_PROTECTION_STATUS_READ_ONLY_DATA = 0x8002u,
+  MTP_PROTECTION_NON_TRANSFERABLE_DATA = 0x8003u,
+} mtp_protection_status_t;
+
+typedef enum {
+  MTP_ASSOCIATION_UNDEFINED            = 0x0000u,
+  MTP_ASSOCIATION_GENERIC_FOLDER       = 0x0001u,
+  MTP_ASSOCIATION_ALBUM                = 0x0002u,
+  MTP_ASSOCIATION_TIME_SEQUENCE        = 0x0003u,
+  MTP_ASSOCIATION_HORIZONTAL_PANORAMIC = 0x0004u,
+  MTP_ASSOCIATION_VERTICAL_PANORAMIC   = 0x0005u,
+  MTP_ASSOCIATION_2D_PANORAMIC         = 0x0006u,
+  MTP_ASSOCIATION_ANCILLARY_DATA       = 0x0007u,
+} mtp_association_t;
+
+//--------------------------------------------------------------------+
+// Data structures
+//--------------------------------------------------------------------+
+typedef struct TU_ATTR_PACKED {
+  uint32_t len;
+  uint16_t type;
+  uint16_t code;
+  uint32_t transaction_id;
+} mtp_container_header_t;
+TU_VERIFY_STATIC(sizeof(mtp_container_header_t) == 12, "size is not correct");
+
+typedef struct TU_ATTR_PACKED {
+  mtp_container_header_t header;
+  uint32_t params[5];
+} mtp_container_command_t;
+TU_VERIFY_STATIC(sizeof(mtp_container_command_t) == 32, "size is not correct");
+
+// PTP/MTP Generic container
+typedef struct TU_ATTR_PACKED {
+  mtp_container_header_t header;
+  uint8_t payload[(CFG_TUD_MTP_EP_BUFSIZE - sizeof(mtp_container_header_t))];
+} mtp_generic_container_t;
+
+typedef struct {
+  mtp_container_header_t* header;
+  union {
+    uint8_t*  payload;
+    uint16_t* payload16;
+    uint32_t* payload32;
+  };
+  uint32_t payload_bytes; // available bytes for read/write
+} mtp_container_info_t;
+
+typedef struct TU_ATTR_PACKED {
+  uint16_t code;
+  uint32_t session_id;
+  uint32_t transaction_id;
+  uint32_t params[3];
+} mtp_event_t;
+TU_VERIFY_STATIC(sizeof(mtp_event_t) == 22, "size is not correct");
+
+#define mtp_string_t(_nchars) \
+  struct TU_ATTR_PACKED { \
+    uint8_t count; /* in characters including null */ \
+    uint16_t utf16[_nchars]; \
+  }
+
+#define mtp_array_t(_type, _count) \
+   struct TU_ATTR_PACKED { \
+     uint32_t count; \
+     _type arr[_count];\
+   }
+
+#define mtp_aint8_t(_count)  mtp_array_t(int8_t, _count)
+#define mtp_auint16_t(_count) mtp_array_t(uint16_t, _count)
+#define mtp_auint32_t(_count) mtp_array_t(uint32_t, _count)
+#define mtp_auint64_t(_count) mtp_array_t(uint64_t, _count)
+
+#define MTP_STORAGE_INFO_STRUCT(_storage_desc_chars, _volume_id_chars) \
+  struct TU_ATTR_PACKED { \
+    uint16_t storage_type; \
+    uint16_t filesystem_type; \
+    uint16_t access_capability; \
+    uint64_t max_capacity_in_bytes; \
+    uint64_t free_space_in_bytes; \
+    uint32_t free_space_in_objects; \
+    mtp_string_t(_storage_desc_chars) storage_description; \
+    mtp_string_t(_volume_id_chars) volume_identifier; \
+  }
+
+// Object Info Dataset without dynamic string: filename, date_created, date_modified, keywords
+typedef struct TU_ATTR_PACKED {
+  uint32_t storage_id;
+  uint16_t object_format;
+  uint16_t protection_status;
+  uint32_t object_compressed_size;
+  uint16_t thumb_format;
+  uint32_t thumb_compressed_size;
+  uint32_t thumb_pix_width;
+  uint32_t thumb_pix_height;
+  uint32_t image_pix_width;
+  uint32_t image_pix_height;
+  uint32_t image_bit_depth;
+  uint32_t parent_object; // 0: root
+  uint16_t association_type;
+  uint32_t association_desc;
+  uint32_t sequence_number;
+  // mtp_string_t() filename
+  // mtp_string_t() date_created
+  // mtp_string_t() date_modified
+  // mtp_string_t() keywords
+} mtp_object_info_header_t;
+
+// Device property desc up to get/set
+typedef struct TU_ATTR_PACKED {
+  uint16_t device_property_code;
+  uint16_t datatype;
+  uint8_t  get_set;
+} mtp_device_prop_desc_header_t;
+
+// The following fields will be dynamically added to the struct at runtime:
+// - wstring factory_def_value;
+// - wstring current_value_len;
+// - uint8_t form_flag;
+
+// no form
+#define MTP_DEVICE_PROPERTIES_STRUCT(_type) \
+   struct TU_ATTR_PACKED { \
+     uint16_t device_property_code; \
+     uint16_t datatype; \
+     uint8_t get_set; \
+     _type factory_default; \
+     _type current_value; \
+     uint8_t form_flag; /* 0: none, 1: range, 2: enum */ \
+   };
+
+typedef struct TU_ATTR_PACKED {
+  uint16_t code;
+  uint32_t transaction_id;
+} mtp_request_reset_cancel_data_t;
+TU_VERIFY_STATIC(sizeof(mtp_request_reset_cancel_data_t) == 6, "size is not correct");
+
+//--------------------------------------------------------------------+
+// Container helper function
+// return number of bytes added
+//--------------------------------------------------------------------+
+
+// return payload buffer for next write
+TU_ATTR_ALWAYS_INLINE static inline uint8_t* mtp_container_payload_ptr(mtp_container_info_t* p_container) {
+  // only 1st packet include header
+  uint32_t pos = p_container->header->len - sizeof(mtp_container_header_t);
+  while (pos > CFG_TUD_MTP_EP_BUFSIZE) {
+    pos -= CFG_TUD_MTP_EP_BUFSIZE;
+  }
+  return p_container->payload + pos;
+}
+
+// only add_raw does partial copy
+TU_ATTR_ALWAYS_INLINE static inline uint32_t mtp_container_add_raw(mtp_container_info_t* p_container, const void* data, uint32_t len) {
+  uint8_t* buf = mtp_container_payload_ptr(p_container);
+  const uint32_t added_len = tu_min32(len, CFG_TUD_MTP_EP_BUFSIZE - p_container->header->len);
+  if (added_len > 0) {
+    memcpy(buf, data, added_len);
+  }
+  p_container->header->len += len; // always increase len, even partial copy
+  return added_len;
+}
+
+TU_ATTR_ALWAYS_INLINE static inline uint32_t mtp_container_add_array(mtp_container_info_t* p_container, uint8_t scalar_size, uint32_t count, const void* data) {
+  const uint32_t added_len = 4 + count * scalar_size;
+  TU_ASSERT(p_container->header->len + added_len < CFG_TUD_MTP_EP_BUFSIZE, 0);
+  uint8_t* buf = p_container->payload + p_container->header->len - sizeof(mtp_container_header_t);
+
+  tu_unaligned_write32(buf, count);
+  p_container->header->len += 4;
+  buf += 4;
+
+  memcpy(buf, data, count * scalar_size);
+  p_container->header->len += count * scalar_size;
+
+  return added_len;
+}
+
+TU_ATTR_ALWAYS_INLINE static inline uint32_t mtp_container_add_string(mtp_container_info_t* p_container, uint16_t* utf16) {
+  uint8_t count = 0;
+  while (utf16[count] != 0u) {
+    count++;
+  }
+  const uint32_t added_len = 1u + (uint32_t) count * 2u;
+  TU_ASSERT(p_container->header->len + added_len < CFG_TUD_MTP_EP_BUFSIZE, 0);
+  uint8_t* buf = p_container->payload + p_container->header->len - sizeof(mtp_container_header_t);
+
+  *buf++ = count;
+  p_container->header->len++;
+
+  memcpy(buf, utf16, 2u * (uint32_t) count);
+  p_container->header->len += 2u * count;
+
+  return added_len;
+}
+
+TU_ATTR_ALWAYS_INLINE static inline uint32_t mtp_container_add_cstring(mtp_container_info_t* p_container, const char* str) {
+  const uint8_t len = (uint8_t) (strlen(str) + 1); // include null
+  TU_ASSERT(p_container->header->len + 1 + 2 * len < CFG_TUD_MTP_EP_BUFSIZE, 0);
+  uint8_t* buf = p_container->payload + p_container->header->len - sizeof(mtp_container_header_t);
+
+  if (len == 1) {
+    // empty string (null only): single zero byte
+    *buf = 0;
+    p_container->header->len++;
+    return 1u;
+  } else {
+    *buf++ = len;
+    p_container->header->len++;
+
+    for (uint8_t i = 0; i < len; i++) {
+      buf[0] = str[i];
+      buf[1] = 0;
+      buf += 2;
+      p_container->header->len += 2;
+    }
+    return 1u + 2u * len;
+  }
+}
+
+TU_ATTR_ALWAYS_INLINE static inline uint32_t mtp_container_add_uint8(mtp_container_info_t* p_container, uint8_t data) {
+  return mtp_container_add_raw(p_container, &data, 1);
+}
+
+TU_ATTR_ALWAYS_INLINE static inline uint32_t mtp_container_add_uint16(mtp_container_info_t* p_container, uint16_t data) {
+  return mtp_container_add_raw(p_container, &data, 2);
+}
+
+TU_ATTR_ALWAYS_INLINE static inline uint32_t mtp_container_add_uint32(mtp_container_info_t* p_container, uint32_t data) {
+  return mtp_container_add_raw(p_container, &data, 4);
+}
+
+TU_ATTR_ALWAYS_INLINE static inline uint32_t mtp_container_add_uint64(mtp_container_info_t* p_container, uint64_t data) {
+  return mtp_container_add_raw(p_container, &data, 8);
+}
+
+TU_ATTR_ALWAYS_INLINE static inline uint32_t mtp_container_add_uint128(mtp_container_info_t* p_container, const void* data) {
+  return mtp_container_add_raw(p_container, data, 16);
+}
+
+TU_ATTR_ALWAYS_INLINE static inline uint32_t mtp_container_add_auint8(mtp_container_info_t* p_container, uint32_t count, const uint8_t* data) {
+  return mtp_container_add_array(p_container, sizeof(uint8_t), count, data);
+}
+
+TU_ATTR_ALWAYS_INLINE static inline uint32_t mtp_container_add_auint16(mtp_container_info_t* p_container, uint32_t count, const uint16_t* data) {
+  return mtp_container_add_array(p_container, sizeof(uint16_t), count, data);
+}
+
+TU_ATTR_ALWAYS_INLINE static inline uint32_t mtp_container_add_auint32(mtp_container_info_t* p_container, uint32_t count, const uint32_t* data) {
+  return mtp_container_add_array(p_container, sizeof(uint32_t), count, data);
+}
+
+//--------------------------------------------------------------------+
+//
+//--------------------------------------------------------------------+
+TU_ATTR_ALWAYS_INLINE static inline uint32_t mtp_container_get_string(uint8_t* buf, uint16_t utf16[]) {
+  size_t nchars = *buf++;
+  memcpy(utf16, buf, 2u * nchars);
+  return 1u + 2u * nchars;
+}
+
+#ifdef __cplusplus
+ }
+#endif
+
+#endif
+#endif
diff --git a/src/class/mtp/mtp_device.c b/src/class/mtp/mtp_device.c
new file mode 100644
index 000000000..764019e42
--- /dev/null
+++ b/src/class/mtp/mtp_device.c
@@ -0,0 +1,540 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2025 Ennebi Elettronica (https://ennebielettronica.com)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * This file is part of the TinyUSB stack.
+ */
+
+#include "tusb_option.h"
+
+#if (CFG_TUD_ENABLED && CFG_TUD_MTP)
+
+//--------------------------------------------------------------------+
+// INCLUDE
+//--------------------------------------------------------------------+
+#include "device/dcd.h"
+#include "device/usbd.h"
+#include "device/usbd_pvt.h"
+
+#include "mtp_device.h"
+
+// Level where CFG_TUSB_DEBUG must be at least for this driver is logged
+#ifndef CFG_TUD_MTP_LOG_LEVEL
+  #define CFG_TUD_MTP_LOG_LEVEL   CFG_TUD_LOG_LEVEL
+#endif
+
+#define TU_LOG_DRV(...)   TU_LOG(CFG_TUD_MTP_LOG_LEVEL, __VA_ARGS__)
+
+//--------------------------------------------------------------------+
+// Weak stubs: invoked if no strong implementation is available
+//--------------------------------------------------------------------+
+TU_ATTR_WEAK bool tud_mtp_request_cancel_cb(tud_mtp_request_cb_data_t* cb_data) {
+  (void) cb_data;
+  return false;
+}
+TU_ATTR_WEAK bool tud_mtp_request_device_reset_cb(tud_mtp_request_cb_data_t* cb_data) {
+  (void) cb_data;
+  return false;
+}
+TU_ATTR_WEAK int32_t tud_mtp_request_get_extended_event_cb(tud_mtp_request_cb_data_t* cb_data) {
+  (void) cb_data;
+  return -1;
+}
+TU_ATTR_WEAK int32_t tud_mtp_request_get_device_status_cb(tud_mtp_request_cb_data_t* cb_data) {
+  (void) cb_data;
+  return -1;
+}
+TU_ATTR_WEAK bool tud_mtp_request_vendor_cb(tud_mtp_request_cb_data_t* cb_data) {
+  (void) cb_data;
+  return false;
+}
+TU_ATTR_WEAK int32_t tud_mtp_command_received_cb(tud_mtp_cb_data_t * cb_data) {
+  (void) cb_data;
+  return -1;
+}
+TU_ATTR_WEAK int32_t tud_mtp_data_xfer_cb(tud_mtp_cb_data_t* cb_data) {
+  (void) cb_data;
+  return -1;
+}
+TU_ATTR_WEAK int32_t tud_mtp_data_complete_cb(tud_mtp_cb_data_t* cb_data) {
+  (void) cb_data;
+  return -1;
+}
+TU_ATTR_WEAK int32_t tud_mtp_response_complete_cb(tud_mtp_cb_data_t* cb_data) {
+  (void) cb_data;
+  return -1;
+}
+
+//--------------------------------------------------------------------+
+// STRUCT
+//--------------------------------------------------------------------+
+typedef struct {
+  uint8_t rhport;
+  uint8_t itf_num;
+  uint8_t ep_in;
+  uint8_t ep_out;
+  uint8_t ep_event;
+
+  // Bulk Only Transfer (BOT) Protocol
+  uint8_t  phase;
+
+  uint32_t total_len;
+  uint32_t xferred_len;
+
+  uint32_t session_id;
+  mtp_container_command_t command;
+  mtp_container_header_t io_header;
+
+  TU_ATTR_ALIGNED(4) uint8_t control_buf[CFG_TUD_MTP_EP_CONTROL_BUFSIZE];
+} mtpd_interface_t;
+
+typedef struct {
+  TUD_EPBUF_DEF(buf, CFG_TUD_MTP_EP_BUFSIZE);
+  TUD_EPBUF_TYPE_DEF(mtp_event_t, buf_event);
+} mtpd_epbuf_t;
+
+//--------------------------------------------------------------------+
+// INTERNAL FUNCTION DECLARATION
+//--------------------------------------------------------------------+
+static mtpd_interface_t _mtpd_itf;
+CFG_TUD_MEM_SECTION static mtpd_epbuf_t _mtpd_epbuf;
+
+static void preprocess_cmd(mtpd_interface_t* p_mtp, tud_mtp_cb_data_t* cb_data);
+
+//--------------------------------------------------------------------+
+// Debug
+//--------------------------------------------------------------------+
+#if CFG_TUSB_DEBUG >= CFG_TUD_MTP_LOG_LEVEL
+
+TU_ATTR_UNUSED static tu_lookup_entry_t const _mpt_op_lookup[] = {
+{.key = MTP_OP_UNDEFINED                    , .data = "Undefined"                 } ,
+{.key = MTP_OP_GET_DEVICE_INFO              , .data = "GetDeviceInfo"             } ,
+{.key = MTP_OP_OPEN_SESSION                 , .data = "OpenSession"               } ,
+{.key = MTP_OP_CLOSE_SESSION                , .data = "CloseSession"              } ,
+{.key = MTP_OP_GET_STORAGE_IDS              , .data = "GetStorageIDs"             } ,
+{.key = MTP_OP_GET_STORAGE_INFO             , .data = "GetStorageInfo"            } ,
+{.key = MTP_OP_GET_NUM_OBJECTS              , .data = "GetNumObjects"             } ,
+{.key = MTP_OP_GET_OBJECT_HANDLES           , .data = "GetObjectHandles"          } ,
+{.key = MTP_OP_GET_OBJECT_INFO              , .data = "GetObjectInfo"             } ,
+{.key = MTP_OP_GET_OBJECT                   , .data = "GetObject"                 } ,
+{.key = MTP_OP_GET_THUMB                    , .data = "GetThumb"                  } ,
+{.key = MTP_OP_DELETE_OBJECT                , .data = "DeleteObject"              } ,
+{.key = MTP_OP_SEND_OBJECT_INFO             , .data = "SendObjectInfo"            } ,
+{.key = MTP_OP_SEND_OBJECT                  , .data = "SendObject"                } ,
+{.key = MTP_OP_INITIATE_CAPTURE             , .data = "InitiateCapture"           } ,
+{.key = MTP_OP_FORMAT_STORE                 , .data = "FormatStore"               } ,
+{.key = MTP_OP_RESET_DEVICE                 , .data = "ResetDevice"               } ,
+{.key = MTP_OP_SELF_TEST                    , .data = "SelfTest"                  } ,
+{.key = MTP_OP_SET_OBJECT_PROTECTION        , .data = "SetObjectProtection"       } ,
+{.key = MTP_OP_POWER_DOWN                   , .data = "PowerDown"                 } ,
+{.key = MTP_OP_GET_DEVICE_PROP_DESC         , .data = "GetDevicePropDesc"         } ,
+{.key = MTP_OP_GET_DEVICE_PROP_VALUE        , .data = "GetDevicePropValue"        } ,
+{.key = MTP_OP_SET_DEVICE_PROP_VALUE        , .data = "SetDevicePropValue"        } ,
+{.key = MTP_OP_RESET_DEVICE_PROP_VALUE      , .data = "ResetDevicePropValue"      } ,
+{.key = MTP_OP_TERMINATE_OPEN_CAPTURE       , .data = "TerminateOpenCapture"      } ,
+{.key = MTP_OP_MOVE_OBJECT                  , .data = "MoveObject"                } ,
+{.key = MTP_OP_COPY_OBJECT                  , .data = "CopyObject"                } ,
+{.key = MTP_OP_GET_PARTIAL_OBJECT           , .data = "GetPartialObject"          } ,
+{.key = MTP_OP_INITIATE_OPEN_CAPTURE        , .data = "InitiateOpenCapture"       } ,
+{.key = MTP_OP_GET_OBJECT_PROPS_SUPPORTED   , .data = "GetObjectPropsSupported"   } ,
+{.key = MTP_OP_GET_OBJECT_PROP_DESC         , .data = "GetObjectPropDesc"         } ,
+{.key = MTP_OP_GET_OBJECT_PROP_VALUE        , .data = "GetObjectPropValue"        } ,
+{.key = MTP_OP_SET_OBJECT_PROP_VALUE        , .data = "SetObjectPropValue"        } ,
+{.key = MTP_OP_GET_OBJECT_PROPLIST          , .data = "GetObjectPropList"         } ,
+{.key = MTP_OP_GET_OBJECT_PROP_REFERENCES   , .data = "GetObjectPropReferences"   } ,
+{.key = MTP_OP_GET_SERVICE_IDS              , .data = "GetServiceIDs"             } ,
+{.key = MTP_OP_GET_SERVICE_INFO             , .data = "GetServiceInfo"            } ,
+{.key = MTP_OP_GET_SERVICE_CAPABILITIES     , .data = "GetServiceCapabilities"    } ,
+{.key = MTP_OP_GET_SERVICE_PROP_DESC        , .data = "GetServicePropDesc"        } ,
+{.key = MTP_OP_GET_OBJECT_PROP_LIST         , .data = "GetObjectPropList"         } ,
+{.key = MTP_OP_SET_OBJECT_PROP_LIST         , .data = "SetObjectPropList"         } ,
+{.key = MTP_OP_GET_INTERDEPENDENT_PROP_DESC , .data = "GetInterdependentPropDesc" } ,
+{.key = MTP_OP_SEND_OBJECT_PROP_LIST        , .data = "SendObjectPropList"        }
+};
+
+TU_ATTR_UNUSED static tu_lookup_table_t const _mtp_op_table = {
+  .count = TU_ARRAY_SIZE(_mpt_op_lookup),
+  .items = _mpt_op_lookup
+};
+
+TU_ATTR_UNUSED static const char* _mtp_phase_str[] = {
+  "Command",
+  "Data",
+  "Response",
+  "Error"
+};
+
+#endif
+
+
+//--------------------------------------------------------------------+
+// Helper
+//--------------------------------------------------------------------+
+static bool prepare_new_command(mtpd_interface_t* p_mtp) {
+  p_mtp->phase = MTP_PHASE_COMMAND;
+  return usbd_edpt_xfer(p_mtp->rhport, p_mtp->ep_out, _mtpd_epbuf.buf, CFG_TUD_MTP_EP_BUFSIZE, false);
+}
+
+static bool mtpd_data_xfer(mtp_container_info_t* p_container, uint8_t ep_addr) {
+  mtpd_interface_t* p_mtp = &_mtpd_itf;
+  if (p_mtp->phase == MTP_PHASE_COMMAND) {
+    // 1st data block: header + payload
+    p_mtp->phase = MTP_PHASE_DATA;
+    p_mtp->xferred_len = 0;
+
+    if (tu_edpt_dir(ep_addr) == TUSB_DIR_IN) {
+      p_mtp->total_len = p_container->header->len;
+      p_container->header->type = MTP_CONTAINER_TYPE_DATA_BLOCK;
+      p_container->header->transaction_id = p_mtp->command.header.transaction_id;
+      p_mtp->io_header = *p_container->header; // save header for subsequent data
+    } else {
+      // OUT transfer: total length is at least max packet size
+      p_mtp->total_len = tu_max32(p_container->header->len, CFG_TUD_MTP_EP_BUFSIZE);
+    }
+  } else {
+    // subsequent data block: payload only
+    TU_ASSERT(p_mtp->phase == MTP_PHASE_DATA);
+  }
+
+  const uint16_t xact_len = (uint16_t) tu_min32(p_mtp->total_len - p_mtp->xferred_len, CFG_TUD_MTP_EP_BUFSIZE);
+  if (xact_len) {
+    // already transferred all bytes in header's length. Application make an unnecessary extra call
+    TU_VERIFY(usbd_edpt_claim(p_mtp->rhport, ep_addr));
+    TU_ASSERT(usbd_edpt_xfer(p_mtp->rhport, ep_addr, _mtpd_epbuf.buf, xact_len, false));
+  }
+  return true;
+}
+
+bool tud_mtp_data_send(mtp_container_info_t* p_container) {
+  return mtpd_data_xfer(p_container, _mtpd_itf.ep_in);
+}
+
+bool tud_mtp_data_receive(mtp_container_info_t* p_container) {
+  return mtpd_data_xfer(p_container, _mtpd_itf.ep_out);
+}
+
+bool tud_mtp_response_send(mtp_container_info_t* p_container) {
+  mtpd_interface_t* p_mtp = &_mtpd_itf;
+  p_mtp->phase = MTP_PHASE_RESPONSE;
+  p_container->header->type = MTP_CONTAINER_TYPE_RESPONSE_BLOCK;
+  p_container->header->transaction_id = p_mtp->command.header.transaction_id;
+  TU_VERIFY(usbd_edpt_claim(p_mtp->rhport, p_mtp->ep_in));
+  return usbd_edpt_xfer(p_mtp->rhport, p_mtp->ep_in, _mtpd_epbuf.buf, (uint16_t) p_container->header->len, false);
+}
+
+bool tud_mtp_mounted(void) {
+  mtpd_interface_t* p_mtp = &_mtpd_itf;
+  return p_mtp->ep_out != 0 && p_mtp->ep_in != 0;
+}
+
+bool tud_mtp_event_send(mtp_event_t* event) {
+  mtpd_interface_t* p_mtp = &_mtpd_itf;
+  TU_VERIFY(p_mtp->ep_event != 0);
+  _mtpd_epbuf.buf_event = *event;
+  TU_VERIFY(usbd_edpt_claim(p_mtp->rhport, p_mtp->ep_event)); // Claim the endpoint
+  return usbd_edpt_xfer(p_mtp->rhport, p_mtp->ep_event, (uint8_t*) &_mtpd_epbuf.buf_event, sizeof(mtp_event_t), false);
+}
+
+//--------------------------------------------------------------------+
+// USBD Driver API
+//--------------------------------------------------------------------+
+void mtpd_init(void) {
+  tu_memclr(&_mtpd_itf, sizeof(mtpd_interface_t));
+}
+
+bool mtpd_deinit(void) {
+  return true; // nothing to do
+}
+
+void mtpd_reset(uint8_t rhport) {
+  (void) rhport;
+  tu_memclr(&_mtpd_itf, sizeof(mtpd_interface_t));
+}
+
+uint16_t mtpd_open(uint8_t rhport, tusb_desc_interface_t const* itf_desc, uint16_t max_len) {
+  // only support PIMA 15470 protocol
+  TU_VERIFY(TUSB_CLASS_IMAGE == itf_desc->bInterfaceClass &&
+            MTP_SUBCLASS_STILL_IMAGE == itf_desc->bInterfaceSubClass &&
+            MTP_PROTOCOL_PIMA_15470 == itf_desc->bInterfaceProtocol, 0);
+
+  // mtp driver length is fixed
+  const uint16_t mtpd_itf_size = sizeof(tusb_desc_interface_t) + 3 * sizeof(tusb_desc_endpoint_t);
+
+  // Max length must be at least 1 interface + 3 endpoints
+  TU_ASSERT(itf_desc->bNumEndpoints == 3 && max_len >= mtpd_itf_size);
+  mtpd_interface_t* p_mtp = &_mtpd_itf;
+  tu_memclr(p_mtp, sizeof(mtpd_interface_t));
+  p_mtp->rhport = rhport;
+  p_mtp->itf_num = itf_desc->bInterfaceNumber;
+
+  // Open interrupt IN endpoint
+  const tusb_desc_endpoint_t* ep_desc = (const tusb_desc_endpoint_t*) tu_desc_next(itf_desc);
+  TU_ASSERT(ep_desc->bDescriptorType == TUSB_DESC_ENDPOINT && ep_desc->bmAttributes.xfer == TUSB_XFER_INTERRUPT, 0);
+  TU_ASSERT(usbd_edpt_open(rhport, ep_desc), 0);
+  p_mtp->ep_event = ep_desc->bEndpointAddress;
+
+  // Open endpoint pair
+  TU_ASSERT(usbd_open_edpt_pair(rhport, tu_desc_next(ep_desc), 2, TUSB_XFER_BULK, &p_mtp->ep_out, &p_mtp->ep_in), 0);
+  TU_ASSERT(prepare_new_command(p_mtp), 0);
+
+  return mtpd_itf_size;
+}
+
+// Invoked when a control transfer occurred on an interface of this class
+// Driver response accordingly to the request and the transfer stage (setup/data/ack)
+// return false to stall control endpoint (e.g unsupported request)
+bool mtpd_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb_control_request_t const* request) {
+  mtpd_interface_t* p_mtp = &_mtpd_itf;
+  tud_mtp_request_cb_data_t cb_data = {
+    .idx = 0,
+    .stage = stage,
+    .session_id = p_mtp->session_id,
+    .request = request,
+    .buf = p_mtp->control_buf,
+    .bufsize = tu_le16toh(request->wLength),
+  };
+
+  switch (request->bRequest) {
+    case MTP_REQ_CANCEL:
+      TU_LOG_DRV("  MTP request: Cancel\n");
+      if (stage == CONTROL_STAGE_SETUP) {
+        return tud_control_xfer(rhport, request, p_mtp->control_buf, CFG_TUD_MTP_EP_CONTROL_BUFSIZE);
+      } else if (stage == CONTROL_STAGE_ACK) {
+        return tud_mtp_request_cancel_cb(&cb_data);
+      }
+      break;
+
+    case MTP_REQ_GET_EXT_EVENT_DATA:
+      TU_LOG_DRV("  MTP request: Get Extended Event Data\n");
+      if (stage == CONTROL_STAGE_SETUP) {
+        const int32_t len = tud_mtp_request_get_extended_event_cb(&cb_data);
+        TU_VERIFY(len > 0);
+        return tud_control_xfer(rhport,request, p_mtp->control_buf, (uint16_t) len);
+      }
+      break;
+
+    case MTP_REQ_RESET:
+      TU_LOG_DRV("  MTP request: Device Reset\n");
+      // used by the host to return the Still Image Capture Device to the Idle state after the Bulk-pipe has stalled
+      if (stage == CONTROL_STAGE_SETUP) {
+        // clear stalled
+        if (usbd_edpt_stalled(rhport, p_mtp->ep_out)) {
+          usbd_edpt_clear_stall(rhport, p_mtp->ep_out);
+        }
+        if (usbd_edpt_stalled(rhport, p_mtp->ep_in)) {
+          usbd_edpt_clear_stall(rhport, p_mtp->ep_in);
+        }
+      } else if (stage == CONTROL_STAGE_ACK) {
+        prepare_new_command(p_mtp);
+        return tud_mtp_request_device_reset_cb(&cb_data);
+      }
+      break;
+
+    case MTP_REQ_GET_DEVICE_STATUS: {
+      TU_LOG_DRV("  MTP request: Get Device Status\n");
+      if (stage == CONTROL_STAGE_SETUP) {
+        const int32_t len = tud_mtp_request_get_device_status_cb(&cb_data);
+        TU_VERIFY(len > 0);
+        return tud_control_xfer(rhport, request, p_mtp->control_buf, (uint16_t) len);
+      }
+      break;
+    }
+
+    default:
+      return tud_mtp_request_vendor_cb(&cb_data);
+  }
+
+  return true;
+}
+
+// Transfer on bulk endpoints
+bool mtpd_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t event, uint32_t xferred_bytes) {
+  if (ep_addr == _mtpd_itf.ep_event) {
+    // nothing to do
+    return true;
+  }
+
+  mtpd_interface_t* p_mtp = &_mtpd_itf;
+  mtp_generic_container_t* p_container = (mtp_generic_container_t*) _mtpd_epbuf.buf;
+
+#if CFG_TUSB_DEBUG >= CFG_TUD_MTP_LOG_LEVEL
+  tu_lookup_find(&_mtp_op_table, p_mtp->command.header.code);
+  TU_LOG_DRV("  MTP %s: %s phase\r\n", (const char *) tu_lookup_find(&_mtp_op_table, p_mtp->command.header.code),
+    _mtp_phase_str[p_mtp->phase]);
+#endif
+
+  const mtp_container_info_t headered_packet = {
+    .header = &p_container->header,
+    .payload = p_container->payload,
+    .payload_bytes = CFG_TUD_MTP_EP_BUFSIZE - sizeof(mtp_container_header_t)
+  };
+
+  const mtp_container_info_t headerless_packet = {
+    .header = &p_mtp->io_header,
+    .payload = _mtpd_epbuf.buf,
+    .payload_bytes = CFG_TUD_MTP_EP_BUFSIZE
+  };
+
+  tud_mtp_cb_data_t cb_data;
+  cb_data.idx = 0;
+  cb_data.phase = p_mtp->phase;
+  cb_data.session_id = p_mtp->session_id;
+  cb_data.command_container = &p_mtp->command;
+  cb_data.io_container = headered_packet;
+  cb_data.total_xferred_bytes = 0;
+  cb_data.xfer_result = event;
+
+  switch (p_mtp->phase) {
+    case MTP_PHASE_COMMAND: {
+      // received new command
+      TU_VERIFY(ep_addr == p_mtp->ep_out && p_container->header.type == MTP_CONTAINER_TYPE_COMMAND_BLOCK);
+      memcpy(&p_mtp->command, p_container, sizeof(mtp_container_command_t)); // save new command
+      p_container->header.len = sizeof(mtp_container_header_t); // default container to header only
+      preprocess_cmd(p_mtp, &cb_data);
+      if (tud_mtp_command_received_cb(&cb_data) < 0) {
+        p_mtp->phase = MTP_PHASE_ERROR;
+      }
+      break;
+    }
+
+    case MTP_PHASE_DATA: {
+      const uint16_t bulk_mps = (tud_speed_get() == TUSB_SPEED_HIGH) ? 512 : 64;
+      p_mtp->xferred_len += xferred_bytes;
+      cb_data.total_xferred_bytes = p_mtp->xferred_len;
+
+      bool is_complete = false;
+      // complete if ZLP or short packet or overflow
+      if (xferred_bytes == 0 || // ZLP
+          (xferred_bytes & (bulk_mps - 1)) || // short packet
+          p_mtp->xferred_len > p_mtp->total_len) {
+        is_complete = true;
+      }
+
+      if (ep_addr == p_mtp->ep_in) {
+        // Data In
+        if (is_complete) {
+          cb_data.io_container.header->len = sizeof(mtp_container_header_t);
+          tud_mtp_data_complete_cb(&cb_data);
+        } else {
+          // 2nd+ packet: payload only
+          cb_data.io_container = headerless_packet;
+          tud_mtp_data_xfer_cb(&cb_data);
+        }
+      } else {
+        // Data Out
+        if (p_mtp->xferred_len == xferred_bytes) {
+          // 1st OUT packet: header + payload
+          p_mtp->io_header = p_container->header; // save header for subsequent transaction
+          cb_data.io_container.payload_bytes = xferred_bytes - sizeof(mtp_container_header_t);
+        } else {
+          // 2nd+ packet: payload only
+          cb_data.io_container = headerless_packet;
+          cb_data.io_container.payload_bytes = xferred_bytes;
+        }
+        tud_mtp_data_xfer_cb(&cb_data);
+
+        if (is_complete) {
+          // back to header + payload for response
+          cb_data.io_container = headered_packet;
+          cb_data.io_container.header->len = sizeof(mtp_container_header_t);
+          tud_mtp_data_complete_cb(&cb_data);
+        }
+      }
+      break;
+    }
+
+    case MTP_PHASE_RESPONSE:
+      // response phase is complete -> prepare for new command
+      TU_ASSERT(ep_addr == p_mtp->ep_in);
+      tud_mtp_response_complete_cb(&cb_data);
+      prepare_new_command(p_mtp);
+      break;
+
+    case MTP_PHASE_ERROR:
+      // handled after switch, supposedly to be empty
+      break;
+    default: return false;
+  }
+
+   if (p_mtp->phase == MTP_PHASE_ERROR) {
+    // stall both IN & OUT endpoints
+    usbd_edpt_stall(rhport, p_mtp->ep_out);
+    usbd_edpt_stall(rhport, p_mtp->ep_in);
+  }
+
+  return true;
+}
+
+
+//--------------------------------------------------------------------+
+// MTPD Internal functionality
+//--------------------------------------------------------------------+
+
+// pre-processed commands
+void preprocess_cmd(mtpd_interface_t* p_mtp, tud_mtp_cb_data_t* cb_data) {
+  switch (p_mtp->command.header.code) {
+    case MTP_OP_GET_DEVICE_INFO: {
+      tud_mtp_device_info_t dev_info = {
+        .standard_version = 100,
+        .mtp_vendor_extension_id = 6, // MTP specs say 0xFFFFFFFF but libMTP check for value 6
+        .mtp_version = 100,
+        .mtp_extensions = {
+          .count = sizeof(CFG_TUD_MTP_DEVICEINFO_EXTENSIONS),
+          .utf16 = { 0 }
+        },
+        .functional_mode = 0x0000,
+        .supported_operations = {
+          .count = TU_ARGS_NUM(CFG_TUD_MTP_DEVICEINFO_SUPPORTED_OPERATIONS),
+          .arr = { CFG_TUD_MTP_DEVICEINFO_SUPPORTED_OPERATIONS }
+        },
+        .supported_events = {
+          .count = TU_ARGS_NUM(CFG_TUD_MTP_DEVICEINFO_SUPPORTED_EVENTS),
+          .arr = { CFG_TUD_MTP_DEVICEINFO_SUPPORTED_EVENTS }
+        },
+        .supported_device_properties = {
+          .count = TU_ARGS_NUM(CFG_TUD_MTP_DEVICEINFO_SUPPORTED_DEVICE_PROPERTIES),
+          .arr = { CFG_TUD_MTP_DEVICEINFO_SUPPORTED_DEVICE_PROPERTIES }
+        },
+        .capture_formats = {
+          .count = TU_ARGS_NUM(CFG_TUD_MTP_DEVICEINFO_CAPTURE_FORMATS),
+          .arr = { CFG_TUD_MTP_DEVICEINFO_CAPTURE_FORMATS }
+        },
+        .playback_formats = {
+          .count = TU_ARGS_NUM(CFG_TUD_MTP_DEVICEINFO_PLAYBACK_FORMATS),
+          .arr = { CFG_TUD_MTP_DEVICEINFO_PLAYBACK_FORMATS }
+        }
+      };
+
+      for (uint8_t i=0; i < dev_info.mtp_extensions.count; i++) {
+        dev_info.mtp_extensions.utf16[i] = (uint16_t)CFG_TUD_MTP_DEVICEINFO_EXTENSIONS[i];
+      }
+
+      mtp_container_add_raw(&cb_data->io_container, &dev_info, sizeof(tud_mtp_device_info_t));
+      break;
+    }
+
+    default:
+      break;
+  }
+}
+
+#endif
diff --git a/src/class/mtp/mtp_device.h b/src/class/mtp/mtp_device.h
new file mode 100644
index 000000000..a33f1dc08
--- /dev/null
+++ b/src/class/mtp/mtp_device.h
@@ -0,0 +1,169 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2025 Ennebi Elettronica (https://ennebielettronica.com)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN0
+ * THE SOFTWARE.
+ *
+ * This file is part of the TinyUSB stack.
+ */
+
+#ifndef TUSB_MTP_DEVICE_H_
+#define TUSB_MTP_DEVICE_H_
+
+#include "common/tusb_common.h"
+#include "mtp.h"
+
+#if (CFG_TUD_ENABLED && CFG_TUD_MTP)
+
+#ifdef __cplusplus
+ extern "C" {
+#endif
+
+// callback data for Bulk Only Transfer (BOT) protocol
+typedef struct {
+  uint8_t idx; // mtp instance
+  uint8_t phase; // current phase
+  uint32_t session_id;
+
+  const mtp_container_command_t* command_container;
+  mtp_container_info_t io_container;
+
+  tusb_xfer_result_t xfer_result;
+  uint32_t total_xferred_bytes; // number of bytes transferred so far in this phase
+} tud_mtp_cb_data_t;
+
+// callback data for Control requests
+typedef struct {
+  uint8_t idx;
+  uint8_t stage; // control stage
+
+  // buffer for data stage
+  uint16_t bufsize;
+  uint8_t* buf;
+
+  const tusb_control_request_t* request;
+
+  uint32_t session_id;
+} tud_mtp_request_cb_data_t;
+
+// Number of supported operations, events, device properties, capture formats, playback formats
+// and max number of characters for strings manufacturer, model, device_version, serial_number
+#define MTP_DEVICE_INFO_STRUCT(_extension_nchars, _op_count, _event_count, _devprop_count, _capture_count, _playback_count) \
+  struct TU_ATTR_PACKED { \
+    uint16_t standard_version; \
+    uint32_t mtp_vendor_extension_id; \
+    uint16_t mtp_version; \
+    mtp_string_t(_extension_nchars) mtp_extensions; \
+    uint16_t functional_mode; \
+    mtp_auint16_t(_op_count) supported_operations; \
+    mtp_auint16_t(_event_count) supported_events; \
+    mtp_auint16_t(_devprop_count) supported_device_properties; \
+    mtp_auint16_t(_capture_count) capture_formats; \
+    mtp_auint16_t(_playback_count) playback_formats; \
+    /* string fields will be added using append function */ \
+  }
+
+typedef MTP_DEVICE_INFO_STRUCT( //-V2586 [MISRA-C-18.7] Flexible array members should not be declared
+  sizeof(CFG_TUD_MTP_DEVICEINFO_EXTENSIONS), TU_ARGS_NUM(CFG_TUD_MTP_DEVICEINFO_SUPPORTED_OPERATIONS),
+  TU_ARGS_NUM(CFG_TUD_MTP_DEVICEINFO_SUPPORTED_EVENTS), TU_ARGS_NUM(CFG_TUD_MTP_DEVICEINFO_SUPPORTED_DEVICE_PROPERTIES),
+  TU_ARGS_NUM(CFG_TUD_MTP_DEVICEINFO_CAPTURE_FORMATS), TU_ARGS_NUM(CFG_TUD_MTP_DEVICEINFO_PLAYBACK_FORMATS)
+) tud_mtp_device_info_t;
+
+//--------------------------------------------------------------------+
+// Application API
+//--------------------------------------------------------------------+
+
+// check if mtp interface is mounted
+bool tud_mtp_mounted(void);
+
+// send data phase
+bool tud_mtp_data_send(mtp_container_info_t* p_container);
+
+// receive data phase
+bool tud_mtp_data_receive(mtp_container_info_t* p_container);
+
+// send response
+bool tud_mtp_response_send(mtp_container_info_t* p_container);
+
+// send event notification on event endpoint
+bool tud_mtp_event_send(mtp_event_t* event);
+
+//--------------------------------------------------------------------+
+// Control request Callbacks
+//--------------------------------------------------------------------+
+
+// Invoked when received Cancel request. Data is available in callback data's buffer
+// return false to stall the request
+bool tud_mtp_request_cancel_cb(tud_mtp_request_cb_data_t* cb_data);
+
+// Invoked when received Device Reset request
+// return false to stall the request
+bool tud_mtp_request_device_reset_cb(tud_mtp_request_cb_data_t* cb_data);
+
+// Invoked when received Get Extended Event request. Application fill callback data's buffer for response
+// return negative to stall the request
+int32_t tud_mtp_request_get_extended_event_cb(tud_mtp_request_cb_data_t* cb_data);
+
+// Invoked when received Get DeviceStatus request. Application fill callback data's buffer for response
+// return negative to stall the request
+int32_t tud_mtp_request_get_device_status_cb(tud_mtp_request_cb_data_t* cb_data);
+
+// Invoked when received vendor-specific request not in the above standard MTP requests
+// return false to stall the request
+bool tud_mtp_request_vendor_cb(tud_mtp_request_cb_data_t* cb_data);
+
+//--------------------------------------------------------------------+
+// Bulk only protocol Callbacks
+//--------------------------------------------------------------------+
+
+// Invoked when new command is received. Application fill the cb_data->io_container and call tud_mtp_data_send() or
+// tud_mtp_response_send() for Data or Response phase.
+// Return negative to stall the endpoints
+int32_t tud_mtp_command_received_cb(tud_mtp_cb_data_t * cb_data);
+
+// Invoked when a data packet is transferred. If data spans over multiple packets, application can use
+// total_xferred_bytes and io_container's payload_bytes to determine the offset and remaining bytes to be transferred.
+// Return negative to stall the endpoints
+int32_t tud_mtp_data_xfer_cb(tud_mtp_cb_data_t* cb_data);
+
+// Invoked when all bytes in DATA phase is complete. A response packet is expected
+// Return negative to stall the endpoints
+int32_t tud_mtp_data_complete_cb(tud_mtp_cb_data_t* cb_data);
+
+// Invoked when response phase is complete
+// Return negative to stall the endpoints
+int32_t tud_mtp_response_complete_cb(tud_mtp_cb_data_t* cb_data);
+
+//--------------------------------------------------------------------+
+// Internal Class Driver API
+//--------------------------------------------------------------------+
+void     mtpd_init            (void);
+bool     mtpd_deinit          (void);
+void     mtpd_reset           (uint8_t rhport);
+uint16_t mtpd_open            (uint8_t rhport, tusb_desc_interface_t const *itf_desc, uint16_t max_len);
+bool     mtpd_control_xfer_cb (uint8_t rhport, uint8_t stage, tusb_control_request_t const *p_request);
+bool     mtpd_xfer_cb         (uint8_t rhport, uint8_t ep_addr, xfer_result_t event, uint32_t xferred_bytes);
+
+#ifdef __cplusplus
+ }
+#endif
+
+#endif
+#endif
diff --git a/src/class/net/ecm_rndis_device.c b/src/class/net/ecm_rndis_device.c
index 299eb97c8..eaa82c187 100644
--- a/src/class/net/ecm_rndis_device.c
+++ b/src/class/net/ecm_rndis_device.c
@@ -35,8 +35,6 @@
 #include "net_device.h"
 #include "rndis_protocol.h"
 
-extern void rndis_class_set_handler(uint8_t *data, int size); /* found in ./misc/networking/rndis_reports.c */
-
 #define CFG_TUD_NET_PACKET_PREFIX_LEN sizeof(rndis_data_packet_t)
 #define CFG_TUD_NET_PACKET_SUFFIX_LEN 0
 
@@ -84,12 +82,12 @@ static bool can_xmit;
 static bool ecm_link_is_up = true;  // Store link state for ECM mode
 
 void tud_network_recv_renew(void) {
-  usbd_edpt_xfer(0, _netd_itf.ep_out, _netd_epbuf.rx, NETD_PACKET_SIZE);
+  usbd_edpt_xfer(0, _netd_itf.ep_out, _netd_epbuf.rx, NETD_PACKET_SIZE, false);
 }
 
 static void do_in_xfer(uint8_t *buf, uint16_t len) {
   can_xmit = false;
-  usbd_edpt_xfer(0, _netd_itf.ep_in, buf, len);
+  usbd_edpt_xfer(0, _netd_itf.ep_in, buf, len, false);
 }
 
 void netd_report(uint8_t *buf, uint16_t len) {
@@ -102,7 +100,7 @@ void netd_report(uint8_t *buf, uint16_t len) {
   }
 
   memcpy(_netd_epbuf.notify, buf, len);
-  usbd_edpt_xfer(rhport, _netd_itf.ep_notif, _netd_epbuf.notify, len);
+  usbd_edpt_xfer(rhport, _netd_itf.ep_notif, _netd_epbuf.notify, len, false);
 }
 
 //--------------------------------------------------------------------+
diff --git a/src/class/net/ncm.h b/src/class/net/ncm.h
index 0245a87f2..8989fe0b4 100644
--- a/src/class/net/ncm.h
+++ b/src/class/net/ncm.h
@@ -25,8 +25,8 @@
  * This file is part of the TinyUSB stack.
  */
 
-#ifndef _TUSB_NCM_H_
-#define _TUSB_NCM_H_
+#ifndef TUSB_NCM_H_
+#define TUSB_NCM_H_
 
 #include "common/tusb_common.h"
 
diff --git a/src/class/net/ncm_device.c b/src/class/net/ncm_device.c
index 02833c5f1..3e19b5f3a 100644
--- a/src/class/net/ncm_device.c
+++ b/src/class/net/ncm_device.c
@@ -50,10 +50,6 @@
 
 #if (CFG_TUD_ENABLED && CFG_TUD_NCM)
 
-#include <stdbool.h>
-#include <stdint.h>
-#include <stdio.h>
-
 #include "device/usbd.h"
 #include "device/usbd_pvt.h"
 
@@ -205,7 +201,7 @@ static void notification_xmit(uint8_t rhport, bool force_next) {
 
     uint16_t notif_len = sizeof(notify_speed_change.header) + notify_speed_change.header.wLength;
     ncm_epbuf.epnotif = notify_speed_change;
-    usbd_edpt_xfer(rhport, ncm_interface.ep_notif, (uint8_t*) &ncm_epbuf.epnotif, notif_len);
+    usbd_edpt_xfer(rhport, ncm_interface.ep_notif, (uint8_t*) &ncm_epbuf.epnotif, notif_len, false);
 
     ncm_interface.notification_xmit_state = NOTIFICATION_CONNECTED;
     ncm_interface.notification_xmit_is_running = true;
@@ -227,7 +223,7 @@ static void notification_xmit(uint8_t rhport, bool force_next) {
 
     uint16_t notif_len = sizeof(notify_connected.header) + notify_connected.header.wLength;
     ncm_epbuf.epnotif = notify_connected;
-    usbd_edpt_xfer(rhport, ncm_interface.ep_notif, (uint8_t *) &ncm_epbuf.epnotif, notif_len);
+    usbd_edpt_xfer(rhport, ncm_interface.ep_notif, (uint8_t *) &ncm_epbuf.epnotif, notif_len, false);
 
     ncm_interface.notification_xmit_state = NOTIFICATION_DONE;
     ncm_interface.notification_xmit_is_running = true;
@@ -331,7 +327,7 @@ static bool xmit_insert_required_zlp(uint8_t rhport, uint32_t xferred_bytes) {
   TU_LOG_DRV("xmit_insert_required_zlp! (%u)\n", (unsigned) xferred_bytes);
 
   // start transmission of the ZLP
-  usbd_edpt_xfer(rhport, ncm_interface.ep_in, NULL, 0);
+  usbd_edpt_xfer(rhport, ncm_interface.ep_in, NULL, 0, false);
 
   return true;
 } // xmit_insert_required_zlp
@@ -377,7 +373,7 @@ static void xmit_start_if_possible(uint8_t rhport) {
   }
 
   // Kick off an endpoint transfer
-  usbd_edpt_xfer(0, ncm_interface.ep_in, ncm_interface.xmit_tinyusb_ntb->data, ncm_interface.xmit_tinyusb_ntb->nth.wBlockLength);
+  usbd_edpt_xfer(0, ncm_interface.ep_in, ncm_interface.xmit_tinyusb_ntb->data, ncm_interface.xmit_tinyusb_ntb->nth.wBlockLength, false);
 } // xmit_start_if_possible
 
 /**
@@ -526,7 +522,7 @@ static void recv_try_to_start_new_reception(uint8_t rhport) {
 
   // initiate transfer
   TU_LOG_DRV("  start reception\n");
-  bool r = usbd_edpt_xfer(rhport, ncm_interface.ep_out, ncm_interface.recv_tinyusb_ntb->data, CFG_TUD_NCM_OUT_NTB_MAX_SIZE);
+  bool r = usbd_edpt_xfer(rhport, ncm_interface.ep_out, ncm_interface.recv_tinyusb_ntb->data, CFG_TUD_NCM_OUT_NTB_MAX_SIZE, false);
   if (!r) {
     recv_put_ntb_into_free_list(ncm_interface.recv_tinyusb_ntb);
     ncm_interface.recv_tinyusb_ntb = NULL;
diff --git a/src/class/net/net_device.h b/src/class/net/net_device.h
index fff2623b7..96c03fd61 100644
--- a/src/class/net/net_device.h
+++ b/src/class/net/net_device.h
@@ -25,8 +25,8 @@
  * This file is part of the TinyUSB stack.
  */
 
-#ifndef _TUSB_NET_DEVICE_H_
-#define _TUSB_NET_DEVICE_H_
+#ifndef TUSB_NET_DEVICE_H_
+#define TUSB_NET_DEVICE_H_
 
 #include <stdint.h>
 #include "class/cdc/cdc.h"
@@ -56,6 +56,13 @@ typedef enum
 #endif
 
 //--------------------------------------------------------------------+
+// Implemented by Application
+//--------------------------------------------------------------------+
+#if CFG_TUD_ECM_RNDIS
+extern void rndis_class_set_handler(uint8_t *data, int size);
+#endif
+
+//--------------------------------------------------------------------+
 // Application API
 //--------------------------------------------------------------------+
 
@@ -107,4 +114,4 @@ void     netd_report          (uint8_t *buf, uint16_t len);
  }
 #endif
 
-#endif /* _TUSB_NET_DEVICE_H_ */
+#endif /* TUSB_NET_DEVICE_H_ */
diff --git a/src/class/usbtmc/usbtmc.h b/src/class/usbtmc/usbtmc.h
index 327de087c..3bf5e1a17 100644
--- a/src/class/usbtmc/usbtmc.h
+++ b/src/class/usbtmc/usbtmc.h
@@ -25,8 +25,8 @@
  * This file is part of the TinyUSB stack.
  */
 
-#ifndef _TUSB_USBTMC_H__
-#define _TUSB_USBTMC_H__
+#ifndef TUSB_USBTMC_H__
+#define TUSB_USBTMC_H__
 
 #include "common/tusb_common.h"
 
diff --git a/src/class/usbtmc/usbtmc_device.c b/src/class/usbtmc/usbtmc_device.c
index 3f6bedd4c..4b0bb01ec 100644
--- a/src/class/usbtmc/usbtmc_device.c
+++ b/src/class/usbtmc/usbtmc_device.c
@@ -261,7 +261,7 @@ bool tud_usbtmc_transmit_dev_msg_data(
   bool stateChanged =
       atomicChangeState(STATE_TX_REQUESTED, (packetLen >= txBufLen) ? STATE_TX_INITIATED : STATE_TX_SHORTED);
   TU_VERIFY(stateChanged);
-  TU_VERIFY(usbd_edpt_xfer(usbtmc_state.rhport, usbtmc_state.ep_bulk_in, usbtmc_epbuf.epin, (uint16_t) packetLen));
+  TU_VERIFY(usbd_edpt_xfer(usbtmc_state.rhport, usbtmc_state.ep_bulk_in, usbtmc_epbuf.epin, (uint16_t) packetLen, false));
   return true;
 }
 
@@ -273,7 +273,7 @@ bool tud_usbtmc_transmit_notification_data(const void *data, size_t len) {
   TU_VERIFY(usbd_edpt_busy(usbtmc_state.rhport, usbtmc_state.ep_int_in));
 
   TU_VERIFY(tu_memcpy_s(usbtmc_epbuf.epnotif, CFG_TUD_USBTMC_INT_EP_SIZE, data, len) == 0);
-  TU_VERIFY(usbd_edpt_xfer(usbtmc_state.rhport, usbtmc_state.ep_int_in, usbtmc_epbuf.epnotif, (uint16_t) len));
+  TU_VERIFY(usbd_edpt_xfer(usbtmc_state.rhport, usbtmc_state.ep_int_in, usbtmc_epbuf.epnotif, (uint16_t) len, false));
   return true;
 }
 
@@ -396,7 +396,7 @@ bool tud_usbtmc_start_bus_read(void) {
     default:
       return false;
   }
-  TU_VERIFY(usbd_edpt_xfer(usbtmc_state.rhport, usbtmc_state.ep_bulk_out, usbtmc_epbuf.epout, (uint16_t) usbtmc_state.ep_bulk_out_wMaxPacketSize));
+  TU_VERIFY(usbd_edpt_xfer(usbtmc_state.rhport, usbtmc_state.ep_bulk_out, usbtmc_epbuf.epout, (uint16_t) usbtmc_state.ep_bulk_out_wMaxPacketSize, false));
   return true;
 }
 
@@ -567,7 +567,7 @@ bool usbtmcd_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint
         if (usbtmc_state.transfer_size_remaining >= USBTMCD_BUFFER_SIZE) {
           // Copy buffer to ensure alignment correctness
           memcpy(usbtmc_epbuf.epin, usbtmc_state.devInBuffer, USBTMCD_BUFFER_SIZE);
-          TU_VERIFY(usbd_edpt_xfer(rhport, usbtmc_state.ep_bulk_in, usbtmc_epbuf.epin, USBTMCD_BUFFER_SIZE));
+          TU_VERIFY(usbd_edpt_xfer(rhport, usbtmc_state.ep_bulk_in, usbtmc_epbuf.epin, USBTMCD_BUFFER_SIZE, false));
           usbtmc_state.devInBuffer += USBTMCD_BUFFER_SIZE;
           usbtmc_state.transfer_size_remaining -= USBTMCD_BUFFER_SIZE;
           usbtmc_state.transfer_size_sent += USBTMCD_BUFFER_SIZE;
@@ -578,7 +578,7 @@ bool usbtmcd_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint
           usbtmc_state.transfer_size_sent += packetLen;
           usbtmc_state.transfer_size_remaining = 0;
           usbtmc_state.devInBuffer = NULL;
-          TU_VERIFY(usbd_edpt_xfer(rhport, usbtmc_state.ep_bulk_in, usbtmc_epbuf.epin, (uint16_t) packetLen));
+          TU_VERIFY(usbd_edpt_xfer(rhport, usbtmc_state.ep_bulk_in, usbtmc_epbuf.epin, (uint16_t) packetLen, false));
           if (((packetLen % usbtmc_state.ep_bulk_in_wMaxPacketSize) != 0) || (packetLen == 0)) {
             usbtmc_state.state = STATE_TX_SHORTED;
           }
@@ -587,7 +587,7 @@ bool usbtmcd_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint
 
       case STATE_ABORTING_BULK_IN:
         // need to send short packet  (ZLP?)
-        TU_VERIFY(usbd_edpt_xfer(rhport, usbtmc_state.ep_bulk_in, usbtmc_epbuf.epin, (uint16_t) 0u));
+        TU_VERIFY(usbd_edpt_xfer(rhport, usbtmc_state.ep_bulk_in, usbtmc_epbuf.epin, (uint16_t) 0u, false));
         usbtmc_state.state = STATE_ABORTING_BULK_IN_SHORTED;
         return true;
 
@@ -713,7 +713,7 @@ bool usbtmcd_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb_control_request
         criticalLeave();
         if (usbtmc_state.transfer_size_sent == 0) {
           // Send short packet, nothing is in the buffer yet
-          TU_VERIFY(usbd_edpt_xfer(rhport, usbtmc_state.ep_bulk_in, usbtmc_epbuf.epin, (uint16_t) 0u));
+          TU_VERIFY(usbd_edpt_xfer(rhport, usbtmc_state.ep_bulk_in, usbtmc_epbuf.epin, (uint16_t) 0u, false));
           usbtmc_state.state = STATE_ABORTING_BULK_IN_SHORTED;
         }
         TU_VERIFY(tud_usbtmc_initiate_abort_bulk_in_cb(&(rsp.USBTMC_status)));
@@ -841,7 +841,7 @@ bool usbtmcd_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb_control_request
                   },
                   .StatusByte = tud_usbtmc_get_stb_cb(&(rsp.USBTMC_status))};
           // Must be queued before control request response sent (USB488v1.0 4.3.1.2)
-          usbd_edpt_xfer(rhport, usbtmc_state.ep_int_in, (void *) &intMsg, sizeof(intMsg));
+          usbd_edpt_xfer(rhport, usbtmc_state.ep_int_in, (void *) &intMsg, sizeof(intMsg), false);
         }
       } else {
         rsp.statusByte = tud_usbtmc_get_stb_cb(&(rsp.USBTMC_status));
diff --git a/src/class/vendor/vendor_device.c b/src/class/vendor/vendor_device.c
index 27724b194..7da4d2239 100644
--- a/src/class/vendor/vendor_device.c
+++ b/src/class/vendor/vendor_device.c
@@ -202,8 +202,9 @@ void vendord_reset(uint8_t rhport) {
     vendord_interface_t* p_itf = &_vendord_itf[i];
     tu_memclr(p_itf, ITF_MEM_RESET_SIZE);
     tu_edpt_stream_clear(&p_itf->rx.stream);
-    tu_edpt_stream_clear(&p_itf->tx.stream);
     tu_edpt_stream_close(&p_itf->rx.stream);
+
+    tu_edpt_stream_clear(&p_itf->tx.stream);
     tu_edpt_stream_close(&p_itf->tx.stream);
   }
 }
@@ -233,16 +234,18 @@ uint16_t vendord_open(uint8_t rhport, const tusb_desc_interface_t* desc_itf, uin
       const tusb_desc_endpoint_t* desc_ep = (const tusb_desc_endpoint_t*) p_desc;
       TU_ASSERT(usbd_edpt_open(rhport, desc_ep));
 
-      // open endpoint stream, skip if already opened
+      // open endpoint stream, skip if already opened (multiple IN/OUT endpoints)
       if (tu_edpt_dir(desc_ep->bEndpointAddress) == TUSB_DIR_IN) {
-        if (p_vendor->tx.stream.ep_addr == 0) {
-          tu_edpt_stream_open(&p_vendor->tx.stream, desc_ep);
-          tud_vendor_n_write_flush(itf);
+        tu_edpt_stream_t *stream_tx = &p_vendor->tx.stream;
+        if (stream_tx->ep_addr == 0) {
+          tu_edpt_stream_open(stream_tx, desc_ep);
+          tu_edpt_stream_write_xfer(rhport, stream_tx); // flush pending data
         }
       } else {
-        if (p_vendor->rx.stream.ep_addr == 0) {
-          tu_edpt_stream_open(&p_vendor->rx.stream, desc_ep);
-          TU_ASSERT(tu_edpt_stream_read_xfer(rhport, &p_vendor->rx.stream) > 0, 0); // prepare for incoming data
+        tu_edpt_stream_t *stream_rx = &p_vendor->rx.stream;
+        if (stream_rx->ep_addr == 0) {
+          tu_edpt_stream_open(stream_rx, desc_ep);
+          TU_ASSERT(tu_edpt_stream_read_xfer(rhport, stream_rx) > 0, 0); // prepare for incoming data
         }
       }
     }
diff --git a/src/class/vendor/vendor_device.h b/src/class/vendor/vendor_device.h
index 5fe4fc9ff..5376f3917 100644
--- a/src/class/vendor/vendor_device.h
+++ b/src/class/vendor/vendor_device.h
@@ -24,8 +24,8 @@
  * This file is part of the TinyUSB stack.
  */
 
-#ifndef _TUSB_VENDOR_DEVICE_H_
-#define _TUSB_VENDOR_DEVICE_H_
+#ifndef TUSB_VENDOR_DEVICE_H_
+#define TUSB_VENDOR_DEVICE_H_
 
 #include "common/tusb_common.h"
 
@@ -141,4 +141,4 @@ bool     vendord_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t event, u
  }
 #endif
 
-#endif /* _TUSB_VENDOR_DEVICE_H_ */
+#endif /* TUSB_VENDOR_DEVICE_H_ */
diff --git a/src/class/vendor/vendor_host.h b/src/class/vendor/vendor_host.h
index acfebe7a4..00e3c3402 100644
--- a/src/class/vendor/vendor_host.h
+++ b/src/class/vendor/vendor_host.h
@@ -24,8 +24,8 @@
  * This file is part of the TinyUSB stack.
  */
 
-#ifndef _TUSB_VENDOR_HOST_H_
-#define _TUSB_VENDOR_HOST_H_
+#ifndef TUSB_VENDOR_HOST_H_
+#define TUSB_VENDOR_HOST_H_
 
 #include "common/tusb_common.h"
 
@@ -64,4 +64,4 @@ void cush_close(uint8_t dev_addr);
  }
 #endif
 
-#endif /* _TUSB_VENDOR_HOST_H_ */
+#endif /* TUSB_VENDOR_HOST_H_ */
diff --git a/src/class/video/video.h b/src/class/video/video.h
index f348e187b..5bdf4b840 100644
--- a/src/class/video/video.h
+++ b/src/class/video/video.h
@@ -219,11 +219,11 @@ typedef enum {
     uint8_t  baInterfaceNr[_nitf]; \
   }
 
-typedef tusb_desc_video_control_header_nitf_t()  tusb_desc_video_control_header_t;
-typedef tusb_desc_video_control_header_nitf_t(1) tusb_desc_video_control_header_1itf_t;
-typedef tusb_desc_video_control_header_nitf_t(2) tusb_desc_video_control_header_2itf_t;
-typedef tusb_desc_video_control_header_nitf_t(3) tusb_desc_video_control_header_3itf_t;
-typedef tusb_desc_video_control_header_nitf_t(4) tusb_desc_video_control_header_4itf_t;
+typedef tusb_desc_video_control_header_nitf_t()  tusb_desc_video_control_header_t; //-V2586 incorrectly detected as flexible array
+typedef tusb_desc_video_control_header_nitf_t(1) tusb_desc_video_control_header_1itf_t; //-V2586 incorrectly detected as flexible array
+typedef tusb_desc_video_control_header_nitf_t(2) tusb_desc_video_control_header_2itf_t; //-V2586 incorrectly detected as flexible array
+typedef tusb_desc_video_control_header_nitf_t(3) tusb_desc_video_control_header_3itf_t; //-V2586 incorrectly detected as flexible array
+typedef tusb_desc_video_control_header_nitf_t(4) tusb_desc_video_control_header_4itf_t; //-V2586 incorrectly detected as flexible array
 
 typedef struct TU_ATTR_PACKED {
   uint8_t  bLength;
diff --git a/src/class/video/video_device.c b/src/class/video/video_device.c
index 5c00cc358..b2375def9 100644
--- a/src/class/video/video_device.c
+++ b/src/class/video/video_device.c
@@ -103,7 +103,7 @@ typedef struct TU_ATTR_PACKED {
   uint8_t index_vc;  /* index of bound video control interface */
   uint8_t index_vs;  /* index from the video control interface */
   struct {
-    uint16_t beg;    /* Offset of the begging of video streaming interface descriptor */
+    uint16_t beg;    /* Offset of the beginning of video streaming interface descriptor */
     uint16_t end;    /* Offset of the end of video streaming interface descriptor */
     uint16_t cur;    /* Offset of the current settings */
     uint16_t ep[2];  /* Offset of endpoint descriptors. 0: streaming, 1: still capture */
@@ -214,6 +214,12 @@ TU_ATTR_WEAK int tud_video_commit_cb(uint_fast8_t ctl_idx, uint_fast8_t stm_idx,
   return VIDEO_ERROR_NONE;
 }
 
+TU_ATTR_WEAK void tud_video_prepare_payload_cb(uint_fast8_t ctl_idx, uint_fast8_t stm_idx, tud_video_payload_request_t* request) {
+  (void) ctl_idx;
+  (void) stm_idx;
+  (void) request;
+}
+
 //--------------------------------------------------------------------+
 //
 //--------------------------------------------------------------------+
@@ -244,9 +250,13 @@ static inline uint8_t _desc_ep_addr(void const *desc) {
  * @return instance */
 static videod_streaming_interface_t* _get_instance_streaming(uint_fast8_t ctl_idx, uint_fast8_t stm_idx) {
   videod_interface_t *ctl = &_videod_itf[ctl_idx];
-  if (!ctl->beg) return NULL;
+  if (!ctl->beg) {
+    return NULL;
+  }
   videod_streaming_interface_t *stm = &_videod_streaming_itf[ctl->stm[stm_idx]];
-  if (!stm->desc.beg) return NULL;
+  if (!stm->desc.beg) {
+    return NULL;
+  }
   return stm;
 }
 
@@ -255,7 +265,9 @@ static tusb_desc_vc_itf_t const* _get_desc_vc(videod_interface_t const *self) {
 }
 
 static tusb_desc_vs_itf_t const* _get_desc_vs(videod_streaming_interface_t const *self) {
-  if (!self->desc.cur) return NULL;
+  if (!self->desc.cur) {
+    return NULL;
+  }
   uint8_t const *desc = _videod_itf[self->index_vc].beg;
   return (tusb_desc_vs_itf_t const*)(desc + self->desc.cur);
 }
@@ -366,8 +378,12 @@ static void const* _find_desc_ep(void const *beg, void const *end)
 {
   for (void const *cur = beg; cur < end; cur = tu_desc_next(cur)) {
     uint_fast8_t desc_type = tu_desc_type(cur);
-    if (TUSB_DESC_ENDPOINT == desc_type) return cur;
-    if (TUSB_DESC_INTERFACE == desc_type) break;
+    if (TUSB_DESC_ENDPOINT == desc_type) {
+      return cur;
+    }
+    if (TUSB_DESC_INTERFACE == desc_type) {
+      break;
+    }
   }
   return end;
 }
@@ -453,8 +469,10 @@ static bool _update_streaming_parameters(videod_streaming_interface_t const *stm
   tusb_desc_vs_itf_t const *vs = _get_desc_vs(stm);
   uint_fast8_t fmtnum = param->bFormatIndex;
   TU_ASSERT(vs && fmtnum <= vs->stm.bNumFormats);
-  if (!fmtnum) {
-    if (1 < vs->stm.bNumFormats) return true; /* Need to negotiate all variables. */
+  if (0 == fmtnum) {
+    if (1 < vs->stm.bNumFormats) {
+      return true; /* Need to negotiate all variables. */
+    }
     fmtnum = 1;
     param->bFormatIndex = 1;
   }
@@ -492,8 +510,10 @@ static bool _update_streaming_parameters(videod_streaming_interface_t const *stm
 
   uint_fast8_t frmnum = param->bFrameIndex;
   TU_ASSERT(frmnum <= fmt->bNumFrameDescriptors);
-  if (!frmnum) {
-    if (1 < fmt->bNumFrameDescriptors) return true;
+  if (0 == frmnum) {
+    if (1 < fmt->bNumFrameDescriptors) {
+      return true;
+    }
     frmnum = 1;
     param->bFrameIndex = 1;
   }
@@ -502,7 +522,7 @@ static bool _update_streaming_parameters(videod_streaming_interface_t const *stm
 
   /* Set the parameters determined by the frame  */
   uint_fast32_t frame_size = param->dwMaxVideoFrameSize;
-  if (!frame_size) {
+  if (0 == frame_size) {
     switch (fmt->bDescriptorSubType) {
       case VIDEO_CS_ITF_VS_FORMAT_UNCOMPRESSED:
         frame_size = (uint_fast32_t)frm->wWidth * frm->wHeight * fmt->uncompressed.bBitsPerPixel / 8;
@@ -522,7 +542,7 @@ static bool _update_streaming_parameters(videod_streaming_interface_t const *stm
   }
 
   uint_fast32_t interval = param->dwFrameInterval;
-  if (!interval) {
+  if (0 == interval) {
     if ((1 < frm->uncompressed.bFrameIntervalType) ||
         ((0 == frm->uncompressed.bFrameIntervalType) &&
          (frm->uncompressed.dwFrameInterval[1] != frm->uncompressed.dwFrameInterval[0]))) {
@@ -532,7 +552,7 @@ static bool _update_streaming_parameters(videod_streaming_interface_t const *stm
     param->dwFrameInterval = interval;
   }
   uint_fast32_t interval_ms = interval / 10000;
-  TU_ASSERT(interval_ms);
+  TU_ASSERT(interval_ms != 0);
   uint_fast32_t payload_size = (frame_size + interval_ms - 1) / interval_ms + 2;
   if (CFG_TUD_VIDEO_STREAMING_EP_BUFSIZE < payload_size) {
     payload_size = CFG_TUD_VIDEO_STREAMING_EP_BUFSIZE;
@@ -550,7 +570,7 @@ static bool _negotiate_streaming_parameters(videod_streaming_interface_t const *
                                             video_probe_and_commit_control_t *param)
 {
   uint_fast8_t const fmtnum = param->bFormatIndex;
-  if (!fmtnum) {
+  if (0 == fmtnum) {
     switch (request) {
       case VIDEO_REQUEST_GET_MAX:
         if (_get_desc_vs(stm))
@@ -581,7 +601,7 @@ static bool _negotiate_streaming_parameters(videod_streaming_interface_t const *
   }
 
   uint_fast8_t frmnum = param->bFrameIndex;
-  if (!frmnum) {
+  if (0 == frmnum) {
     tusb_desc_vs_itf_t const *vs = _get_desc_vs(stm);
     TU_ASSERT(vs);
     void const *end = _end_of_streaming_descriptor(vs);
@@ -637,7 +657,7 @@ static bool _negotiate_streaming_parameters(videod_streaming_interface_t const *
     return true;
   }
 
-  if (!param->dwFrameInterval) {
+  if (0 == param->dwFrameInterval) {
     tusb_desc_vs_itf_t const *vs = _get_desc_vs(stm);
     TU_ASSERT(vs);
     void const *end = _end_of_streaming_descriptor(vs);
@@ -686,12 +706,12 @@ static bool _negotiate_streaming_parameters(videod_streaming_interface_t const *
       default: return false;
     }
     param->dwFrameInterval = interval;
-    if (!interval) {
+    if (0 == interval) {
       param->dwMaxPayloadTransferSize = 0;
     } else {
       uint_fast32_t frame_size = param->dwMaxVideoFrameSize;
       uint_fast32_t payload_size;
-      if (!interval_ms) {
+      if (0 == interval_ms) {
         payload_size = frame_size + 2;
       } else {
         payload_size = (frame_size + interval_ms - 1) / interval_ms + 2;
@@ -719,7 +739,7 @@ static bool _close_vc_itf(uint8_t rhport, videod_interface_t *self)
 
   /* The end of the video control interface descriptor. */
   void const *end = _end_of_control_descriptor(vc);
-  if (vc->std.bNumEndpoints) {
+  if (vc->std.bNumEndpoints != 0) {
     /* Find the notification endpoint descriptor. */
     cur = _find_desc(cur, end, TUSB_DESC_ENDPOINT);
     TU_ASSERT(cur < end);
@@ -757,7 +777,7 @@ static bool _open_vc_itf(uint8_t rhport, videod_interface_t *self, uint_fast8_t
   cur += vc->std.bLength + vc->ctl.bLength;
   TU_LOG_DRV("    bNumEndpoints %d\r\n", vc->std.bNumEndpoints);
   /* Open the notification endpoint if it exist. */
-  if (vc->std.bNumEndpoints) {
+  if (vc->std.bNumEndpoints != 0) {
     /* Support for 1 endpoint only. */
     TU_VERIFY(1 == vc->std.bNumEndpoints);
     /* Find the notification endpoint descriptor. */
@@ -843,7 +863,7 @@ static bool _open_vs_itf(uint8_t rhport, videod_streaming_interface_t *stm, uint
     stm->desc.ep[i] = (uint16_t) (cur - desc);
     TU_LOG_DRV("    open EP%02x\r\n", _desc_ep_addr(cur));
   }
-  if (altnum) {
+  if (altnum != 0) {
     stm->state = VS_STATE_STREAMING;
   }
   TU_LOG_DRV("    done\r\n");
@@ -860,7 +880,16 @@ static uint_fast16_t _prepare_in_payload(videod_streaming_interface_t *stm, uint
   }
   TU_ASSERT(pkt_len >= hdr_len);
   uint_fast16_t data_len = pkt_len - hdr_len;
-  memcpy(&ep_buf[hdr_len], stm->buffer + stm->offset, data_len);
+  if (stm->buffer) {
+    memcpy(&ep_buf[hdr_len], stm->buffer + stm->offset, data_len);
+  } else {
+    tud_video_payload_request_t rqst = {
+      .buf = &ep_buf[hdr_len],
+      .length = data_len,
+      .offset = stm->offset
+    };
+    tud_video_prepare_payload_cb(stm->index_vc, stm->index_vs, &rqst);
+  }
   stm->offset += data_len;
   remaining -= data_len;
   if (!remaining) {
@@ -929,16 +958,14 @@ static int handle_video_ctl_cs_req(uint8_t rhport, uint8_t stage,
           return VIDEO_ERROR_NONE;
 
         case VIDEO_REQUEST_GET_CUR:
-          if (stage == CONTROL_STAGE_SETUP)
-          {
+          if (stage == CONTROL_STAGE_SETUP) {
             TU_VERIFY(1 == request->wLength, VIDEO_ERROR_UNKNOWN);
             TU_VERIFY(tud_control_xfer(rhport, request, &self->power_mode, sizeof(self->power_mode)), VIDEO_ERROR_UNKNOWN);
           }
           return VIDEO_ERROR_NONE;
 
         case VIDEO_REQUEST_GET_INFO:
-          if (stage == CONTROL_STAGE_SETUP)
-          {
+          if (stage == CONTROL_STAGE_SETUP) {
             TU_VERIFY(1 == request->wLength, VIDEO_ERROR_UNKNOWN);
             TU_VERIFY(tud_control_xfer(rhport, request, (uint8_t*)(uintptr_t) &_cap_get_set, sizeof(_cap_get_set)), VIDEO_ERROR_UNKNOWN);
           }
@@ -951,15 +978,13 @@ static int handle_video_ctl_cs_req(uint8_t rhport, uint8_t stage,
     case VIDEO_VC_CTL_REQUEST_ERROR_CODE:
       switch (request->bRequest) {
         case VIDEO_REQUEST_GET_CUR:
-          if (stage == CONTROL_STAGE_SETUP)
-          {
+          if (stage == CONTROL_STAGE_SETUP) {
             TU_VERIFY(tud_control_xfer(rhport, request, &self->error_code, sizeof(uint8_t)), VIDEO_ERROR_UNKNOWN);
           }
           return VIDEO_ERROR_NONE;
 
         case VIDEO_REQUEST_GET_INFO:
-          if (stage == CONTROL_STAGE_SETUP)
-          {
+          if (stage == CONTROL_STAGE_SETUP) {
             TU_VERIFY(tud_control_xfer(rhport, request, (uint8_t*)(uintptr_t) &_cap_get, sizeof(_cap_get)), VIDEO_ERROR_UNKNOWN);
           }
           return VIDEO_ERROR_NONE;
@@ -986,7 +1011,7 @@ static int handle_video_ctl_req(uint8_t rhport, uint8_t stage,
 
     case TUSB_REQ_TYPE_CLASS: {
       uint_fast8_t entity_id = TU_U16_HIGH(request->wIndex);
-      if (!entity_id) {
+      if (0 == entity_id) {
         return handle_video_ctl_cs_req(rhport, stage, request, ctl_idx);
       } else {
         TU_VERIFY(_find_desc_entity(_get_desc_vc(&_videod_itf[ctl_idx]), entity_id), VIDEO_ERROR_INVALID_REQUEST);
@@ -1001,14 +1026,12 @@ static int handle_video_ctl_req(uint8_t rhport, uint8_t stage,
 
 static int handle_video_stm_std_req(uint8_t rhport, uint8_t stage,
                                     tusb_control_request_t const *request,
-                                    uint_fast8_t stm_idx)
-{
+                                    uint_fast8_t stm_idx) {
   TU_LOG_DRV("\r\n");
   videod_streaming_interface_t *self = &_videod_streaming_itf[stm_idx];
   switch (request->bRequest) {
     case TUSB_REQ_GET_INTERFACE:
-      if (stage == CONTROL_STAGE_SETUP)
-      {
+      if (stage == CONTROL_STAGE_SETUP) {
         TU_VERIFY(1 == request->wLength, VIDEO_ERROR_UNKNOWN);
         tusb_desc_vs_itf_t const *vs = _get_desc_vs(self);
         TU_VERIFY(vs, VIDEO_ERROR_UNKNOWN);
@@ -1075,12 +1098,14 @@ static int handle_video_stm_cs_req(uint8_t rhport, uint8_t stage,
           } else if (stage == CONTROL_STAGE_DATA) {
             TU_VERIFY(_update_streaming_parameters(stm, &stm->probe_commit_payload),
                       VIDEO_ERROR_INVALID_VALUE_WITHIN_RANGE);
+          } else {
+            // nothing to do
           }
           return VIDEO_ERROR_NONE;
 
         case VIDEO_REQUEST_GET_CUR:
           if (stage == CONTROL_STAGE_SETUP) {
-            TU_VERIFY(request->wLength, VIDEO_ERROR_UNKNOWN);
+            TU_VERIFY(request->wLength != 0, VIDEO_ERROR_UNKNOWN);
             TU_VERIFY(tud_control_xfer(rhport, request, &stm->probe_commit_payload, sizeof(video_probe_and_commit_control_t)), VIDEO_ERROR_UNKNOWN);
           }
           return VIDEO_ERROR_NONE;
@@ -1090,7 +1115,7 @@ static int handle_video_stm_cs_req(uint8_t rhport, uint8_t stage,
         case VIDEO_REQUEST_GET_RES:
         case VIDEO_REQUEST_GET_DEF:
           if (stage == CONTROL_STAGE_SETUP) {
-            TU_VERIFY(request->wLength, VIDEO_ERROR_UNKNOWN);
+            TU_VERIFY(request->wLength != 0, VIDEO_ERROR_UNKNOWN);
             video_probe_and_commit_control_t tmp = stm->probe_commit_payload;
             TU_VERIFY(_negotiate_streaming_parameters(stm, request->bRequest, &tmp), VIDEO_ERROR_INVALID_VALUE_WITHIN_RANGE);
             TU_VERIFY(tud_control_xfer(rhport, request, &tmp, sizeof(tmp)), VIDEO_ERROR_UNKNOWN);
@@ -1137,12 +1162,14 @@ static int handle_video_stm_cs_req(uint8_t rhport, uint8_t stage,
               hdr->bHeaderLength = sizeof(*hdr);
               hdr->bmHeaderInfo  = 0;
             }
+          } else {
+            // nothing to do
           }
           return VIDEO_ERROR_NONE;
 
         case VIDEO_REQUEST_GET_CUR:
           if (stage == CONTROL_STAGE_SETUP) {
-            TU_VERIFY(request->wLength, VIDEO_ERROR_UNKNOWN);
+            TU_VERIFY(request->wLength != 0, VIDEO_ERROR_UNKNOWN);
             TU_VERIFY(tud_control_xfer(rhport, request, &stm->probe_commit_payload, sizeof(video_probe_and_commit_control_t)), VIDEO_ERROR_UNKNOWN);
           }
           return VIDEO_ERROR_NONE;
@@ -1185,14 +1212,15 @@ static int handle_video_stm_cs_req(uint8_t rhport, uint8_t stage,
 
 static int handle_video_stm_req(uint8_t rhport, uint8_t stage,
                                 tusb_control_request_t const *request,
-                                uint_fast8_t stm_idx)
-{
+                                uint_fast8_t stm_idx) {
   switch (request->bmRequestType_bit.type) {
     case TUSB_REQ_TYPE_STANDARD:
       return handle_video_stm_std_req(rhport, stage, request, stm_idx);
 
     case TUSB_REQ_TYPE_CLASS:
-      if (TU_U16_HIGH(request->wIndex)) return VIDEO_ERROR_INVALID_REQUEST;
+      if (0 != TU_U16_HIGH(request->wIndex)) {
+        return VIDEO_ERROR_INVALID_REQUEST;
+      }
       return handle_video_stm_cs_req(rhport, stage, request, stm_idx);
 
     default: return VIDEO_ERROR_INVALID_REQUEST;
@@ -1203,11 +1231,12 @@ static int handle_video_stm_req(uint8_t rhport, uint8_t stage,
 // APPLICATION API
 //--------------------------------------------------------------------+
 
-bool tud_video_n_connected(uint_fast8_t ctl_idx)
-{
+bool tud_video_n_connected(uint_fast8_t ctl_idx) {
   TU_ASSERT(ctl_idx < CFG_TUD_VIDEO);
   videod_streaming_interface_t *stm = _get_instance_streaming(ctl_idx, 0);
-  if (stm) return true;
+  if (stm != NULL) {
+    return true;
+  }
   return false;
 }
 
@@ -1216,15 +1245,21 @@ bool tud_video_n_streaming(uint_fast8_t ctl_idx, uint_fast8_t stm_idx)
   TU_ASSERT(ctl_idx < CFG_TUD_VIDEO);
   TU_ASSERT(stm_idx < CFG_TUD_VIDEO_STREAMING);
   videod_streaming_interface_t *stm = _get_instance_streaming(ctl_idx, stm_idx);
-  if (!stm || !stm->desc.ep[0]) return false;
-  if (stm->state == VS_STATE_PROBING) return false;
+  if (NULL == stm || 0 == stm->desc.ep[0]) {
+    return false;
+  }
+  if (stm->state == VS_STATE_PROBING) {
+    return false;
+  }
 
-#ifdef TUP_DCD_EDPT_ISO_ALLOC
+  #ifdef TUP_DCD_EDPT_ISO_ALLOC
   uint8_t const *desc = _videod_itf[stm->index_vc].beg;
   uint_fast16_t ofs_ep = stm->desc.ep[0];
   tusb_desc_endpoint_t const *ep = (tusb_desc_endpoint_t const*)(desc + ofs_ep);
   if (ep->bmAttributes.xfer == TUSB_XFER_ISOCHRONOUS) {
-    if (stm->state == VS_STATE_COMMITTED) return false;
+    if (stm->state == VS_STATE_COMMITTED) {
+      return false;
+    }
   }
 #endif
 
@@ -1235,25 +1270,36 @@ bool tud_video_n_frame_xfer(uint_fast8_t ctl_idx, uint_fast8_t stm_idx, void *bu
   TU_ASSERT(ctl_idx < CFG_TUD_VIDEO);
   TU_ASSERT(stm_idx < CFG_TUD_VIDEO_STREAMING);
 
-  if (!buffer || !bufsize) return false;
+  if (0 == bufsize) {
+    return false;
+  }
+
   videod_streaming_interface_t *stm = _get_instance_streaming(ctl_idx, stm_idx);
   videod_streaming_epbuf_t *stm_epbuf = &_videod_streaming_epbuf[ctl_idx];
 
-  if (!stm || !stm->desc.ep[0] || stm->buffer) return false;
-  if (stm->state == VS_STATE_PROBING) return false;
+  if (NULL == stm || 0 == stm->desc.ep[0] || stm->bufsize) {
+    return false;
+  }
+  if (stm->state == VS_STATE_PROBING) {
+    return false;
+  }
 
   /* Find EP address */
   uint8_t const *desc = _videod_itf[stm->index_vc].beg;
   uint8_t ep_addr = 0;
   for (uint_fast8_t i = 0; i < CFG_TUD_VIDEO_STREAMING; ++i) {
     uint_fast16_t ofs_ep = stm->desc.ep[i];
-    if (!ofs_ep) continue;
+    if (0 == ofs_ep) {
+      continue;
+    }
     ep_addr = _desc_ep_addr(desc + ofs_ep);
     break;
   }
-  if (!ep_addr) return false;
+  if (0 == ep_addr) {
+    return false;
+  }
 
-  TU_VERIFY( usbd_edpt_claim(0, ep_addr) );
+  TU_VERIFY(usbd_edpt_claim(0, ep_addr));
   /* update the packet header */
   tusb_video_payload_header_t *hdr = (tusb_video_payload_header_t*)stm_epbuf->buf;
   hdr->FrameID   ^= 1;
@@ -1262,7 +1308,7 @@ bool tud_video_n_frame_xfer(uint_fast8_t ctl_idx, uint_fast8_t stm_idx, void *bu
   stm->buffer     = (uint8_t*)buffer;
   stm->bufsize    = bufsize;
   uint_fast16_t pkt_len = _prepare_in_payload(stm, stm_epbuf->buf);
-  TU_ASSERT( usbd_edpt_xfer(0, ep_addr, stm_epbuf->buf, (uint16_t) pkt_len), 0);
+  TU_ASSERT( usbd_edpt_xfer(0, ep_addr, stm_epbuf->buf, (uint16_t) pkt_len, false), 0);
   return true;
 }
 
@@ -1305,7 +1351,9 @@ uint16_t videod_open(uint8_t rhport, tusb_desc_interface_t const * itf_desc, uin
   videod_interface_t *self = NULL;
   uint8_t ctl_idx;
   for (ctl_idx = 0; ctl_idx < CFG_TUD_VIDEO; ++ctl_idx) {
-    if (_videod_itf[ctl_idx].beg) continue;
+    if (NULL != _videod_itf[ctl_idx].beg) {
+      continue;
+    }
     self = &_videod_itf[ctl_idx];
     break;
   }
@@ -1326,7 +1374,9 @@ uint16_t videod_open(uint8_t rhport, tusb_desc_interface_t const * itf_desc, uin
     videod_streaming_interface_t *stm = NULL;
     /* find free streaming interface handle */
     for (uint8_t i = 0; i < CFG_TUD_VIDEO_STREAMING; ++i) {
-      if (_videod_streaming_itf[i].desc.beg) continue;
+      if (0 != _videod_streaming_itf[i].desc.beg) {
+        continue;
+      }
       stm = &_videod_streaming_itf[i];
       self->stm[stm_idx] = i;
       break;
@@ -1354,7 +1404,9 @@ uint16_t videod_open(uint8_t rhport, tusb_desc_interface_t const * itf_desc, uin
       }
       p_desc = tu_desc_next(p_desc);
     }
-    if(ep_addr > 0 && ep_size > 0) usbd_edpt_iso_alloc(rhport, ep_addr, ep_size);
+    if(ep_addr > 0 && ep_size > 0) {
+      usbd_edpt_iso_alloc(rhport, ep_addr, ep_size);
+    }
 #endif
     if (0 == stm_idx && 1 == bInCollection) {
       /* If there is only one streaming interface and no alternate settings,
@@ -1381,31 +1433,43 @@ bool videod_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb_control_request_
   uint_fast8_t itf;
   for (itf = 0; itf < CFG_TUD_VIDEO; ++itf) {
     void const *desc = _videod_itf[itf].beg;
-    if (!desc) continue;
-    if (itfnum == _desc_itfnum(desc)) break;
+    if (!desc) {
+      continue;
+    }
+    if (itfnum == _desc_itfnum(desc)) {
+      break;
+    }
   }
 
   if (itf < CFG_TUD_VIDEO) {
     TU_LOG_DRV("  VC[%d]: ", itf);
     err = handle_video_ctl_req(rhport, stage, request, itf);
     _videod_itf[itf].error_code = (uint8_t)err;
-    if (err) return false;
+    if (0 != err) {
+      return false;
+    }
     return true;
   }
 
   /* Identify which streaming interface to use */
   for (itf = 0; itf < CFG_TUD_VIDEO_STREAMING; ++itf) {
     videod_streaming_interface_t *stm = &_videod_streaming_itf[itf];
-    if (!stm->desc.beg) continue;
+    if (0 == stm->desc.beg) {
+      continue;
+    }
     uint8_t const *desc = _videod_itf[stm->index_vc].beg;
-    if (itfnum == _desc_itfnum(desc + stm->desc.beg)) break;
+    if (itfnum == _desc_itfnum(desc + stm->desc.beg)) {
+      break;
+    }
   }
 
   if (itf < CFG_TUD_VIDEO_STREAMING) {
     TU_LOG_DRV("  VS[%d]: ", itf);
     err = handle_video_stm_req(rhport, stage, request, itf);
     _videod_streaming_itf[itf].error_code = (uint8_t)err;
-    if (err) return false;
+    if (err != 0) {
+      return false;
+    }
     return true;
   }
   return false;
@@ -1421,19 +1485,23 @@ bool videod_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint3
   for (itf = 0; itf < CFG_TUD_VIDEO_STREAMING; ++itf) {
     stm = &_videod_streaming_itf[itf];
     uint_fast16_t const ep_ofs = stm->desc.ep[0];
-    if (!ep_ofs) continue;
+    if (0 == ep_ofs) {
+      continue;
+    }
     ctl = &_videod_itf[stm->index_vc];
     uint8_t const *desc = ctl->beg;
-    if (ep_addr == _desc_ep_addr(desc + ep_ofs)) break;
+    if (ep_addr == _desc_ep_addr(desc + ep_ofs)) {
+      break;
+    }
   }
   TU_ASSERT(itf < CFG_TUD_VIDEO_STREAMING);
   videod_streaming_epbuf_t *stm_epbuf = &_videod_streaming_epbuf[itf];
 
   if (stm->offset < stm->bufsize) {
     /* Claim the endpoint */
-    TU_VERIFY( usbd_edpt_claim(rhport, ep_addr), 0);
+    TU_VERIFY(usbd_edpt_claim(rhport, ep_addr), 0);
     uint_fast16_t pkt_len = _prepare_in_payload(stm, stm_epbuf->buf);
-    TU_ASSERT( usbd_edpt_xfer(rhport, ep_addr, stm_epbuf->buf, (uint16_t) pkt_len), 0);
+    TU_ASSERT(usbd_edpt_xfer(rhport, ep_addr, stm_epbuf->buf, (uint16_t) pkt_len, false), 0);
   } else {
     stm->buffer  = NULL;
     stm->bufsize = 0;
diff --git a/src/class/video/video_device.h b/src/class/video/video_device.h
index 2b41c3bfe..f14555e4f 100644
--- a/src/class/video/video_device.h
+++ b/src/class/video/video_device.h
@@ -35,6 +35,16 @@
 extern "C" {
 #endif
 
+
+//--------------------------------------------------------------------+
+// Payload request
+//--------------------------------------------------------------------+
+typedef struct TU_ATTR_PACKED {
+    void* buf;      /* Payload buffer to be filled */
+    size_t length;  /* Length of the requested data in bytes */
+    size_t offset;  /* Offset within the frame (in bytes) */
+} tud_video_payload_request_t;
+
 //--------------------------------------------------------------------+
 // Application API (Multiple Ports)
 // CFG_TUD_VIDEO > 1
@@ -83,6 +93,16 @@ int tud_video_power_mode_cb(uint_fast8_t ctl_idx, uint8_t power_mod);
 int tud_video_commit_cb(uint_fast8_t ctl_idx, uint_fast8_t stm_idx,
                                      video_probe_and_commit_control_t const *parameters);
 
+/** Invoked if buffer is set to NULL (allows bufferless on the fly data generation)
+ *
+ * @param[in]   ctl_idx       Destination control interface index
+ * @param[in]   stm_idx       Destination streaming interface index
+ * @param[out]  payload_buf   Payload storage buffer (target buffer for requested data)
+ * @param[in]   payload_size  Size of payload_buf (requested data size)
+ * @param[in]   offset        Current byte offset relative to given bufsize from tud_video_n_frame_xfer (framesize)
+ * @return video_error_code_t */
+void tud_video_prepare_payload_cb(uint_fast8_t ctl_idx, uint_fast8_t stm_idx, tud_video_payload_request_t* request);
+
 //--------------------------------------------------------------------+
 // INTERNAL USBD-CLASS DRIVER API
 //--------------------------------------------------------------------+