Merge branch 'master' into dcd_notif

Signed-off-by: HiFiPhile <[email protected]>

22 files changed, 2498 insertions, 1661 deletions

diff --git a/src/class/audio/audio.h b/src/class/audio/audio.h
index d6f3e22e2..2f97c0f23 100644
--- a/src/class/audio/audio.h
+++ b/src/class/audio/audio.h
@@ -489,7 +489,7 @@ typedef enum
   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       = 0x80000000,
+  AUDIO_DATA_FORMAT_TYPE_I_RAW_DATA       = 0x80000000u,
 } audio_data_format_type_I_t;
 
 /// All remaining definitions are taken from the descriptor descriptions in the UAC2 main specification
@@ -640,7 +640,7 @@ typedef enum
   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                   = 0x80000000,
+  AUDIO_CHANNEL_CONFIG_RAW_DATA                   = 0x80000000u,
 } audio_channel_config_t;
 
 /// AUDIO Channel Cluster Descriptor (4.1)
diff --git a/src/class/audio/audio_device.c b/src/class/audio/audio_device.c
index 9ba38a20c..136f658df 100644
--- a/src/class/audio/audio_device.c
+++ b/src/class/audio/audio_device.c
@@ -2,6 +2,7 @@
  * The MIT License (MIT)
  *
  * Copyright (c) 2020 Reinhard Panhuber, Jerzy Kasenberg
+ * Copyright (c) 2023 HiFiPhile
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -65,8 +66,10 @@
 //--------------------------------------------------------------------+
 
 // Use ring buffer if it's available, some MCUs need extra RAM requirements
+// For DWC2 enable ring buffer will disable DMA (if available)
 #ifndef TUD_AUDIO_PREFER_RING_BUFFER
-  #if CFG_TUSB_MCU == OPT_MCU_LPC43XX || CFG_TUSB_MCU == OPT_MCU_LPC18XX || CFG_TUSB_MCU == OPT_MCU_MIMXRT1XXX
+  #if CFG_TUSB_MCU == OPT_MCU_LPC43XX || CFG_TUSB_MCU == OPT_MCU_LPC18XX || CFG_TUSB_MCU == OPT_MCU_MIMXRT1XXX || \
+      defined(TUP_USBIP_DWC2)
     #define TUD_AUDIO_PREFER_RING_BUFFER 0
   #else
     #define TUD_AUDIO_PREFER_RING_BUFFER 1
@@ -118,23 +121,23 @@
 // EP IN software buffers and mutexes
 #if CFG_TUD_AUDIO_ENABLE_EP_IN && !CFG_TUD_AUDIO_ENABLE_ENCODING
   #if CFG_TUD_AUDIO_FUNC_1_EP_IN_SW_BUF_SZ > 0
-    IN_SW_BUF_MEM_SECTION CFG_TUSB_MEM_ALIGN uint8_t audio_ep_in_sw_buf_1[CFG_TUD_AUDIO_FUNC_1_EP_IN_SW_BUF_SZ];
+    tu_static IN_SW_BUF_MEM_SECTION CFG_TUSB_MEM_ALIGN uint8_t audio_ep_in_sw_buf_1[CFG_TUD_AUDIO_FUNC_1_EP_IN_SW_BUF_SZ];
     #if CFG_FIFO_MUTEX
-    osal_mutex_def_t ep_in_ff_mutex_wr_1; // No need for read mutex as only USB driver reads from FIFO
+    tu_static osal_mutex_def_t ep_in_ff_mutex_wr_1; // No need for read mutex as only USB driver reads from FIFO
     #endif
   #endif // CFG_TUD_AUDIO_FUNC_1_EP_IN_SW_BUF_SZ > 0
 
   #if CFG_TUD_AUDIO > 1 && CFG_TUD_AUDIO_FUNC_2_EP_IN_SW_BUF_SZ > 0
-    IN_SW_BUF_MEM_SECTION CFG_TUSB_MEM_ALIGN uint8_t audio_ep_in_sw_buf_2[CFG_TUD_AUDIO_FUNC_2_EP_IN_SW_BUF_SZ];
+    tu_static IN_SW_BUF_MEM_SECTION CFG_TUSB_MEM_ALIGN uint8_t audio_ep_in_sw_buf_2[CFG_TUD_AUDIO_FUNC_2_EP_IN_SW_BUF_SZ];
     #if CFG_FIFO_MUTEX
-    osal_mutex_def_t ep_in_ff_mutex_wr_2; // No need for read mutex as only USB driver reads from FIFO
+    tu_static osal_mutex_def_t ep_in_ff_mutex_wr_2; // No need for read mutex as only USB driver reads from FIFO
     #endif
   #endif // CFG_TUD_AUDIO > 1 && CFG_TUD_AUDIO_FUNC_2_EP_IN_SW_BUF_SZ > 0
 
   #if CFG_TUD_AUDIO > 2 && CFG_TUD_AUDIO_FUNC_3_EP_IN_SW_BUF_SZ > 0
-    IN_SW_BUF_MEM_SECTION CFG_TUSB_MEM_ALIGN uint8_t audio_ep_in_sw_buf_3[CFG_TUD_AUDIO_FUNC_3_EP_IN_SW_BUF_SZ];
+    tu_static IN_SW_BUF_MEM_SECTION CFG_TUSB_MEM_ALIGN uint8_t audio_ep_in_sw_buf_3[CFG_TUD_AUDIO_FUNC_3_EP_IN_SW_BUF_SZ];
     #if CFG_FIFO_MUTEX
-    osal_mutex_def_t ep_in_ff_mutex_wr_3; // No need for read mutex as only USB driver reads from FIFO
+    tu_static osal_mutex_def_t ep_in_ff_mutex_wr_3; // No need for read mutex as only USB driver reads from FIFO
     #endif
   #endif // CFG_TUD_AUDIO > 2 && CFG_TUD_AUDIO_FUNC_3_EP_IN_SW_BUF_SZ > 0
 #endif // CFG_TUD_AUDIO_ENABLE_EP_IN && !CFG_TUD_AUDIO_ENABLE_ENCODING
@@ -144,38 +147,38 @@
 // - the software encoding is used - in this case the linear buffers serve as a target memory where logical channels are encoded into
 #if CFG_TUD_AUDIO_ENABLE_EP_IN && (USE_LINEAR_BUFFER || CFG_TUD_AUDIO_ENABLE_ENCODING)
   #if CFG_TUD_AUDIO_FUNC_1_EP_IN_SZ_MAX > 0
-    CFG_TUD_MEM_SECTION CFG_TUSB_MEM_ALIGN uint8_t lin_buf_in_1[CFG_TUD_AUDIO_FUNC_1_EP_IN_SZ_MAX];
+    tu_static CFG_TUD_MEM_SECTION CFG_TUSB_MEM_ALIGN uint8_t lin_buf_in_1[CFG_TUD_AUDIO_FUNC_1_EP_IN_SZ_MAX];
   #endif
 
   #if CFG_TUD_AUDIO > 1 && CFG_TUD_AUDIO_FUNC_2_EP_IN_SZ_MAX > 0
-    CFG_TUD_MEM_SECTION CFG_TUSB_MEM_ALIGN uint8_t lin_buf_in_2[CFG_TUD_AUDIO_FUNC_2_EP_IN_SZ_MAX];
+    tu_static CFG_TUD_MEM_SECTION CFG_TUSB_MEM_ALIGN uint8_t lin_buf_in_2[CFG_TUD_AUDIO_FUNC_2_EP_IN_SZ_MAX];
   #endif
 
   #if CFG_TUD_AUDIO > 2 && CFG_TUD_AUDIO_FUNC_3_EP_IN_SZ_MAX > 0
-    CFG_TUD_MEM_SECTION CFG_TUSB_MEM_ALIGN uint8_t lin_buf_in_3[CFG_TUD_AUDIO_FUNC_3_EP_IN_SZ_MAX];
+    tu_static CFG_TUD_MEM_SECTION CFG_TUSB_MEM_ALIGN uint8_t lin_buf_in_3[CFG_TUD_AUDIO_FUNC_3_EP_IN_SZ_MAX];
   #endif
 #endif // CFG_TUD_AUDIO_ENABLE_EP_IN && (USE_LINEAR_BUFFER || CFG_TUD_AUDIO_ENABLE_DECODING)
 
 // EP OUT software buffers and mutexes
 #if CFG_TUD_AUDIO_ENABLE_EP_OUT && !CFG_TUD_AUDIO_ENABLE_DECODING
   #if CFG_TUD_AUDIO_FUNC_1_EP_OUT_SW_BUF_SZ > 0
-    OUT_SW_BUF_MEM_SECTION CFG_TUSB_MEM_ALIGN uint8_t audio_ep_out_sw_buf_1[CFG_TUD_AUDIO_FUNC_1_EP_OUT_SW_BUF_SZ];
+    tu_static OUT_SW_BUF_MEM_SECTION CFG_TUSB_MEM_ALIGN uint8_t audio_ep_out_sw_buf_1[CFG_TUD_AUDIO_FUNC_1_EP_OUT_SW_BUF_SZ];
     #if CFG_FIFO_MUTEX
-    osal_mutex_def_t ep_out_ff_mutex_rd_1; // No need for write mutex as only USB driver writes into FIFO
+    tu_static osal_mutex_def_t ep_out_ff_mutex_rd_1; // No need for write mutex as only USB driver writes into FIFO
     #endif
   #endif // CFG_TUD_AUDIO_FUNC_1_EP_OUT_SW_BUF_SZ > 0
 
   #if CFG_TUD_AUDIO > 1 && CFG_TUD_AUDIO_FUNC_2_EP_OUT_SW_BUF_SZ > 0
-    OUT_SW_BUF_MEM_SECTION CFG_TUSB_MEM_ALIGN uint8_t audio_ep_out_sw_buf_2[CFG_TUD_AUDIO_FUNC_2_EP_OUT_SW_BUF_SZ];
+    tu_static OUT_SW_BUF_MEM_SECTION CFG_TUSB_MEM_ALIGN uint8_t audio_ep_out_sw_buf_2[CFG_TUD_AUDIO_FUNC_2_EP_OUT_SW_BUF_SZ];
     #if CFG_FIFO_MUTEX
-    osal_mutex_def_t ep_out_ff_mutex_rd_2; // No need for write mutex as only USB driver writes into FIFO
+    tu_static osal_mutex_def_t ep_out_ff_mutex_rd_2; // No need for write mutex as only USB driver writes into FIFO
     #endif
   #endif // CFG_TUD_AUDIO > 1 && CFG_TUD_AUDIO_FUNC_2_EP_OUT_SW_BUF_SZ > 0
 
   #if CFG_TUD_AUDIO > 2 && CFG_TUD_AUDIO_FUNC_3_EP_OUT_SW_BUF_SZ > 0
-    OUT_SW_BUF_MEM_SECTION CFG_TUSB_MEM_ALIGN uint8_t audio_ep_out_sw_buf_3[CFG_TUD_AUDIO_FUNC_3_EP_OUT_SW_BUF_SZ];
+    tu_static OUT_SW_BUF_MEM_SECTION CFG_TUSB_MEM_ALIGN uint8_t audio_ep_out_sw_buf_3[CFG_TUD_AUDIO_FUNC_3_EP_OUT_SW_BUF_SZ];
     #if CFG_FIFO_MUTEX
-    osal_mutex_def_t ep_out_ff_mutex_rd_3; // No need for write mutex as only USB driver writes into FIFO
+    tu_static osal_mutex_def_t ep_out_ff_mutex_rd_3; // No need for write mutex as only USB driver writes into FIFO
     #endif
   #endif // CFG_TUD_AUDIO > 2 && CFG_TUD_AUDIO_FUNC_3_EP_OUT_SW_BUF_SZ > 0
 #endif // CFG_TUD_AUDIO_ENABLE_EP_OUT && !CFG_TUD_AUDIO_ENABLE_DECODING
@@ -185,89 +188,89 @@
 // - the software encoding is used - in this case the linear buffers serve as a target memory where logical channels are encoded into
 #if CFG_TUD_AUDIO_ENABLE_EP_OUT && (USE_LINEAR_BUFFER || CFG_TUD_AUDIO_ENABLE_DECODING)
   #if CFG_TUD_AUDIO_FUNC_1_EP_OUT_SZ_MAX > 0
-    CFG_TUD_MEM_SECTION CFG_TUSB_MEM_ALIGN uint8_t lin_buf_out_1[CFG_TUD_AUDIO_FUNC_1_EP_OUT_SZ_MAX];
+    tu_static CFG_TUD_MEM_SECTION CFG_TUSB_MEM_ALIGN uint8_t lin_buf_out_1[CFG_TUD_AUDIO_FUNC_1_EP_OUT_SZ_MAX];
   #endif
 
   #if CFG_TUD_AUDIO > 1 && CFG_TUD_AUDIO_FUNC_2_EP_OUT_SZ_MAX > 0
-    CFG_TUD_MEM_SECTION CFG_TUSB_MEM_ALIGN uint8_t lin_buf_out_2[CFG_TUD_AUDIO_FUNC_2_EP_OUT_SZ_MAX];
+    tu_static CFG_TUD_MEM_SECTION CFG_TUSB_MEM_ALIGN uint8_t lin_buf_out_2[CFG_TUD_AUDIO_FUNC_2_EP_OUT_SZ_MAX];
   #endif
 
   #if CFG_TUD_AUDIO > 2 && CFG_TUD_AUDIO_FUNC_3_EP_OUT_SZ_MAX > 0
-    CFG_TUD_MEM_SECTION CFG_TUSB_MEM_ALIGN uint8_t lin_buf_out_3[CFG_TUD_AUDIO_FUNC_3_EP_OUT_SZ_MAX];
+    tu_static CFG_TUD_MEM_SECTION CFG_TUSB_MEM_ALIGN uint8_t lin_buf_out_3[CFG_TUD_AUDIO_FUNC_3_EP_OUT_SZ_MAX];
   #endif
 #endif // CFG_TUD_AUDIO_ENABLE_EP_OUT && (USE_LINEAR_BUFFER || CFG_TUD_AUDIO_ENABLE_DECODING)
 
 // Control buffers
-CFG_TUD_MEM_SECTION CFG_TUSB_MEM_ALIGN uint8_t ctrl_buf_1[CFG_TUD_AUDIO_FUNC_1_CTRL_BUF_SZ];
+tu_static CFG_TUD_MEM_SECTION CFG_TUSB_MEM_ALIGN uint8_t ctrl_buf_1[CFG_TUD_AUDIO_FUNC_1_CTRL_BUF_SZ];
 
 #if CFG_TUD_AUDIO > 1
-CFG_TUD_MEM_SECTION CFG_TUSB_MEM_ALIGN uint8_t ctrl_buf_2[CFG_TUD_AUDIO_FUNC_2_CTRL_BUF_SZ];
+tu_static CFG_TUD_MEM_SECTION CFG_TUSB_MEM_ALIGN uint8_t ctrl_buf_2[CFG_TUD_AUDIO_FUNC_2_CTRL_BUF_SZ];
 #endif
 
 #if CFG_TUD_AUDIO > 2
-CFG_TUD_MEM_SECTION CFG_TUSB_MEM_ALIGN uint8_t ctrl_buf_3[CFG_TUD_AUDIO_FUNC_3_CTRL_BUF_SZ];
+tu_static CFG_TUD_MEM_SECTION CFG_TUSB_MEM_ALIGN uint8_t ctrl_buf_3[CFG_TUD_AUDIO_FUNC_3_CTRL_BUF_SZ];
 #endif
 
 // Active alternate setting of interfaces
-uint8_t alt_setting_1[CFG_TUD_AUDIO_FUNC_1_N_AS_INT];
+tu_static uint8_t alt_setting_1[CFG_TUD_AUDIO_FUNC_1_N_AS_INT];
 
 #if CFG_TUD_AUDIO > 1 && CFG_TUD_AUDIO_FUNC_2_N_AS_INT > 0
-uint8_t alt_setting_2[CFG_TUD_AUDIO_FUNC_2_N_AS_INT];
+tu_static uint8_t alt_setting_2[CFG_TUD_AUDIO_FUNC_2_N_AS_INT];
 #endif
 
 #if CFG_TUD_AUDIO > 2 && CFG_TUD_AUDIO_FUNC_3_N_AS_INT > 0
-uint8_t alt_setting_3[CFG_TUD_AUDIO_FUNC_3_N_AS_INT];
+tu_static uint8_t alt_setting_3[CFG_TUD_AUDIO_FUNC_3_N_AS_INT];
 #endif
 
 // Software encoding/decoding support FIFOs
 #if CFG_TUD_AUDIO_ENABLE_EP_IN && CFG_TUD_AUDIO_ENABLE_ENCODING
   #if CFG_TUD_AUDIO_FUNC_1_TX_SUPP_SW_FIFO_SZ > 0
-    CFG_TUSB_MEM_ALIGN uint8_t tx_supp_ff_buf_1[CFG_TUD_AUDIO_FUNC_1_N_TX_SUPP_SW_FIFO][CFG_TUD_AUDIO_FUNC_1_TX_SUPP_SW_FIFO_SZ];
-    tu_fifo_t tx_supp_ff_1[CFG_TUD_AUDIO_FUNC_1_N_TX_SUPP_SW_FIFO];
+    tu_static CFG_TUSB_MEM_ALIGN uint8_t tx_supp_ff_buf_1[CFG_TUD_AUDIO_FUNC_1_N_TX_SUPP_SW_FIFO][CFG_TUD_AUDIO_FUNC_1_TX_SUPP_SW_FIFO_SZ];
+    tu_static tu_fifo_t tx_supp_ff_1[CFG_TUD_AUDIO_FUNC_1_N_TX_SUPP_SW_FIFO];
     #if CFG_FIFO_MUTEX
-    osal_mutex_def_t tx_supp_ff_mutex_wr_1[CFG_TUD_AUDIO_FUNC_1_N_TX_SUPP_SW_FIFO]; // No need for read mutex as only USB driver reads from FIFO
+    tu_static osal_mutex_def_t tx_supp_ff_mutex_wr_1[CFG_TUD_AUDIO_FUNC_1_N_TX_SUPP_SW_FIFO]; // No need for read mutex as only USB driver reads from FIFO
     #endif
   #endif
 
   #if CFG_TUD_AUDIO > 1 && CFG_TUD_AUDIO_FUNC_2_TX_SUPP_SW_FIFO_SZ > 0
-    CFG_TUSB_MEM_ALIGN uint8_t tx_supp_ff_buf_2[CFG_TUD_AUDIO_FUNC_2_N_TX_SUPP_SW_FIFO][CFG_TUD_AUDIO_FUNC_2_TX_SUPP_SW_FIFO_SZ];
-    tu_fifo_t tx_supp_ff_2[CFG_TUD_AUDIO_FUNC_2_N_TX_SUPP_SW_FIFO];
+    tu_static CFG_TUSB_MEM_ALIGN uint8_t tx_supp_ff_buf_2[CFG_TUD_AUDIO_FUNC_2_N_TX_SUPP_SW_FIFO][CFG_TUD_AUDIO_FUNC_2_TX_SUPP_SW_FIFO_SZ];
+    tu_static tu_fifo_t tx_supp_ff_2[CFG_TUD_AUDIO_FUNC_2_N_TX_SUPP_SW_FIFO];
     #if CFG_FIFO_MUTEX
-    osal_mutex_def_t tx_supp_ff_mutex_wr_2[CFG_TUD_AUDIO_FUNC_2_N_TX_SUPP_SW_FIFO]; // No need for read mutex as only USB driver reads from FIFO
+    tu_static osal_mutex_def_t tx_supp_ff_mutex_wr_2[CFG_TUD_AUDIO_FUNC_2_N_TX_SUPP_SW_FIFO]; // No need for read mutex as only USB driver reads from FIFO
     #endif
   #endif
 
   #if CFG_TUD_AUDIO > 2 && CFG_TUD_AUDIO_FUNC_3_TX_SUPP_SW_FIFO_SZ > 0
-    CFG_TUSB_MEM_ALIGN uint8_t tx_supp_ff_buf_3[CFG_TUD_AUDIO_FUNC_3_N_TX_SUPP_SW_FIFO][CFG_TUD_AUDIO_FUNC_3_TX_SUPP_SW_FIFO_SZ];
-    tu_fifo_t tx_supp_ff_3[CFG_TUD_AUDIO_FUNC_3_N_TX_SUPP_SW_FIFO];
+    tu_static CFG_TUSB_MEM_ALIGN uint8_t tx_supp_ff_buf_3[CFG_TUD_AUDIO_FUNC_3_N_TX_SUPP_SW_FIFO][CFG_TUD_AUDIO_FUNC_3_TX_SUPP_SW_FIFO_SZ];
+    tu_static tu_fifo_t tx_supp_ff_3[CFG_TUD_AUDIO_FUNC_3_N_TX_SUPP_SW_FIFO];
     #if CFG_FIFO_MUTEX
-    osal_mutex_def_t tx_supp_ff_mutex_wr_3[CFG_TUD_AUDIO_FUNC_3_N_TX_SUPP_SW_FIFO]; // No need for read mutex as only USB driver reads from FIFO
+    tu_static osal_mutex_def_t tx_supp_ff_mutex_wr_3[CFG_TUD_AUDIO_FUNC_3_N_TX_SUPP_SW_FIFO]; // No need for read mutex as only USB driver reads from FIFO
     #endif
   #endif
 #endif
 
 #if CFG_TUD_AUDIO_ENABLE_EP_OUT && CFG_TUD_AUDIO_ENABLE_DECODING
   #if CFG_TUD_AUDIO_FUNC_1_RX_SUPP_SW_FIFO_SZ > 0
-    CFG_TUSB_MEM_ALIGN uint8_t rx_supp_ff_buf_1[CFG_TUD_AUDIO_FUNC_1_N_RX_SUPP_SW_FIFO][CFG_TUD_AUDIO_FUNC_1_RX_SUPP_SW_FIFO_SZ];
-    tu_fifo_t rx_supp_ff_1[CFG_TUD_AUDIO_FUNC_1_N_RX_SUPP_SW_FIFO];
+    tu_static CFG_TUSB_MEM_ALIGN uint8_t rx_supp_ff_buf_1[CFG_TUD_AUDIO_FUNC_1_N_RX_SUPP_SW_FIFO][CFG_TUD_AUDIO_FUNC_1_RX_SUPP_SW_FIFO_SZ];
+    tu_static tu_fifo_t rx_supp_ff_1[CFG_TUD_AUDIO_FUNC_1_N_RX_SUPP_SW_FIFO];
     #if CFG_FIFO_MUTEX
-    osal_mutex_def_t rx_supp_ff_mutex_rd_1[CFG_TUD_AUDIO_FUNC_1_N_RX_SUPP_SW_FIFO]; // No need for write mutex as only USB driver writes into FIFO
+    tu_static osal_mutex_def_t rx_supp_ff_mutex_rd_1[CFG_TUD_AUDIO_FUNC_1_N_RX_SUPP_SW_FIFO]; // No need for write mutex as only USB driver writes into FIFO
     #endif
   #endif
 
   #if CFG_TUD_AUDIO > 1 && CFG_TUD_AUDIO_FUNC_2_RX_SUPP_SW_FIFO_SZ > 0
-    CFG_TUSB_MEM_ALIGN uint8_t rx_supp_ff_buf_2[CFG_TUD_AUDIO_FUNC_2_N_RX_SUPP_SW_FIFO][CFG_TUD_AUDIO_FUNC_2_RX_SUPP_SW_FIFO_SZ];
-    tu_fifo_t rx_supp_ff_2[CFG_TUD_AUDIO_FUNC_2_N_RX_SUPP_SW_FIFO];
+    tu_static CFG_TUSB_MEM_ALIGN uint8_t rx_supp_ff_buf_2[CFG_TUD_AUDIO_FUNC_2_N_RX_SUPP_SW_FIFO][CFG_TUD_AUDIO_FUNC_2_RX_SUPP_SW_FIFO_SZ];
+    tu_static tu_fifo_t rx_supp_ff_2[CFG_TUD_AUDIO_FUNC_2_N_RX_SUPP_SW_FIFO];
     #if CFG_FIFO_MUTEX
-    osal_mutex_def_t rx_supp_ff_mutex_rd_2[CFG_TUD_AUDIO_FUNC_2_N_RX_SUPP_SW_FIFO]; // No need for write mutex as only USB driver writes into FIFO
+    tu_static osal_mutex_def_t rx_supp_ff_mutex_rd_2[CFG_TUD_AUDIO_FUNC_2_N_RX_SUPP_SW_FIFO]; // No need for write mutex as only USB driver writes into FIFO
     #endif
   #endif
 
   #if CFG_TUD_AUDIO > 2 && CFG_TUD_AUDIO_FUNC_3_RX_SUPP_SW_FIFO_SZ > 0
-    CFG_TUSB_MEM_ALIGN uint8_t rx_supp_ff_buf_3[CFG_TUD_AUDIO_FUNC_3_N_RX_SUPP_SW_FIFO][CFG_TUD_AUDIO_FUNC_3_RX_SUPP_SW_FIFO_SZ];
-    tu_fifo_t rx_supp_ff_3[CFG_TUD_AUDIO_FUNC_3_N_RX_SUPP_SW_FIFO];
+    tu_static CFG_TUSB_MEM_ALIGN uint8_t rx_supp_ff_buf_3[CFG_TUD_AUDIO_FUNC_3_N_RX_SUPP_SW_FIFO][CFG_TUD_AUDIO_FUNC_3_RX_SUPP_SW_FIFO_SZ];
+    tu_static tu_fifo_t rx_supp_ff_3[CFG_TUD_AUDIO_FUNC_3_N_RX_SUPP_SW_FIFO];
     #if CFG_FIFO_MUTEX
-    osal_mutex_def_t rx_supp_ff_mutex_rd_3[CFG_TUD_AUDIO_FUNC_3_N_RX_SUPP_SW_FIFO]; // No need for write mutex as only USB driver writes into FIFO
+    tu_static osal_mutex_def_t rx_supp_ff_mutex_rd_3[CFG_TUD_AUDIO_FUNC_3_N_RX_SUPP_SW_FIFO]; // No need for write mutex as only USB driver writes into FIFO
     #endif
   #endif
 #endif
@@ -300,32 +303,18 @@ typedef struct
 
   bool mounted;                 // Device opened
 
-  /*------------- From this point, data is not cleared by bus reset -------------*/
-
   uint16_t desc_length;         // Length of audio function descriptor
 
-  // Buffer for control requests
-  uint8_t * ctrl_buf;
-  uint8_t ctrl_buf_sz;
-
-  // Current active alternate settings
-  uint8_t * alt_setting;   // We need to save the current alternate setting this way, because it is possible that there are AS interfaces which do not have an EP!
-
-  // EP Transfer buffers and FIFOs
-#if CFG_TUD_AUDIO_ENABLE_EP_OUT
-#if !CFG_TUD_AUDIO_ENABLE_DECODING
-  tu_fifo_t ep_out_ff;
-#endif
-
 #if CFG_TUD_AUDIO_ENABLE_FEEDBACK_EP
   struct {
-    CFG_TUSB_MEM_ALIGN uint32_t value;  // Feedback value for asynchronous mode (in 16.16 format).
+    CFG_TUSB_MEM_ALIGN uint32_t send_buf;
+    uint32_t value;       // Feedback value for asynchronous mode (in 16.16 format).
     uint32_t min_value;   // min value according to UAC2 FMT-2.0 section 2.3.1.1.
     uint32_t max_value;   // max value according to UAC2 FMT-2.0 section 2.3.1.1.
 
     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
@@ -335,28 +324,17 @@ typedef struct
         uint32_t mclk_freq;
       }fixed;
 
-#if 0 // implement later
       struct {
-        uint32_t nominal_value;
-        uint32_t threshold_bytes;
+        uint32_t nom_value;     // In 16.16 format
+        uint32_t fifo_lvl_avg;  // In 16.16 format
+        uint16_t fifo_lvl_thr;  // fifo level threshold
+        uint16_t rate_const[2]; // pre-computed feedback/fifo_depth rate
       }fifo_count;
-#endif
     }compute;
 
   } feedback;
 #endif // CFG_TUD_AUDIO_ENABLE_FEEDBACK_EP
 
-#endif // CFG_TUD_AUDIO_ENABLE_EP_OUT
-
-#if CFG_TUD_AUDIO_ENABLE_EP_IN && !CFG_TUD_AUDIO_ENABLE_ENCODING
-  tu_fifo_t ep_in_ff;
-#endif
-
-  // Audio control interrupt buffer - no FIFO - 6 Bytes according to UAC 2 specification (p. 74)
-#if CFG_TUD_AUDIO_ENABLE_INTERRUPT_EP
-  CFG_TUSB_MEM_ALIGN uint8_t ep_int_buf[6];
-#endif
-
   // Decoding parameters - parameters are set when alternate AS interface is set by host
   // Coding is currently only supported for EP. Software coding corresponding to AS interfaces without EPs are not supported currently.
 #if CFG_TUD_AUDIO_ENABLE_EP_OUT && CFG_TUD_AUDIO_ENABLE_DECODING
@@ -365,8 +343,7 @@ typedef struct
 
 #if CFG_TUD_AUDIO_ENABLE_TYPE_I_DECODING
   audio_data_format_type_I_t format_type_I_rx;
-  uint8_t n_bytes_per_sampe_rx;
-  uint8_t n_channels_per_ff_rx;
+  uint8_t n_bytes_per_sample_rx;
   uint8_t n_ff_used_rx;
 #endif
 #endif
@@ -382,26 +359,54 @@ typedef struct
 #if CFG_TUD_AUDIO_ENABLE_EP_IN && (CFG_TUD_AUDIO_ENABLE_ENCODING || CFG_TUD_AUDIO_EP_IN_FLOW_CONTROL)
   audio_format_type_t format_type_tx;
   uint8_t n_channels_tx;
-  uint8_t n_bytes_per_sampe_tx;
+  uint8_t n_bytes_per_sample_tx;
 
 #if CFG_TUD_AUDIO_ENABLE_TYPE_I_ENCODING
   audio_data_format_type_I_t format_type_I_tx;
-  uint8_t n_channels_per_ff_tx;
   uint8_t n_ff_used_tx;
 #endif
 #endif
 
+  /*------------- From this point, data is not cleared by bus reset -------------*/
+
+  // Buffer for control requests
+  uint8_t * ctrl_buf;
+  uint8_t ctrl_buf_sz;
+
+  // Current active alternate settings
+  uint8_t * alt_setting;   // We need to save the current alternate setting this way, because it is possible that there are AS interfaces which do not have an EP!
+
+  // EP Transfer buffers and FIFOs
+#if CFG_TUD_AUDIO_ENABLE_EP_OUT && !CFG_TUD_AUDIO_ENABLE_DECODING
+  tu_fifo_t ep_out_ff;
+#endif
+
+#if CFG_TUD_AUDIO_ENABLE_EP_IN && !CFG_TUD_AUDIO_ENABLE_ENCODING
+  tu_fifo_t ep_in_ff;
+#endif
+
+  // Audio control interrupt buffer - no FIFO - 6 Bytes according to UAC 2 specification (p. 74)
+#if CFG_TUD_AUDIO_ENABLE_INTERRUPT_EP
+  CFG_TUSB_MEM_ALIGN uint8_t ep_int_buf[6];
+#endif
+
   // Support FIFOs for software encoding and decoding
 #if CFG_TUD_AUDIO_ENABLE_EP_OUT && CFG_TUD_AUDIO_ENABLE_DECODING
   tu_fifo_t * rx_supp_ff;
   uint8_t n_rx_supp_ff;
   uint16_t rx_supp_ff_sz_max;
+#if CFG_TUD_AUDIO_ENABLE_TYPE_I_DECODING
+  uint8_t n_channels_per_ff_rx;
+#endif
 #endif
 
 #if CFG_TUD_AUDIO_ENABLE_EP_IN && CFG_TUD_AUDIO_ENABLE_ENCODING
   tu_fifo_t * tx_supp_ff;
   uint8_t n_tx_supp_ff;
   uint16_t tx_supp_ff_sz_max;
+#if CFG_TUD_AUDIO_ENABLE_TYPE_I_ENCODING
+  uint8_t n_channels_per_ff_tx;
+#endif
 #endif
 
   // 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 OR the support FIFOs are used
@@ -428,9 +433,146 @@ typedef struct
 #define ITF_MEM_RESET_SIZE   offsetof(audiod_function_t, ctrl_buf)
 
 //--------------------------------------------------------------------+
+// WEAK FUNCTION STUBS
+//--------------------------------------------------------------------+
+
+#if CFG_TUD_AUDIO_ENABLE_EP_IN
+TU_ATTR_WEAK bool tud_audio_tx_done_pre_load_cb(uint8_t rhport, uint8_t func_id, uint8_t ep_in, uint8_t cur_alt_setting) {
+  (void) rhport;
+  (void) func_id;
+  (void) ep_in;
+  (void) cur_alt_setting;
+  return true;
+}
+
+TU_ATTR_WEAK bool tud_audio_tx_done_post_load_cb(uint8_t rhport, uint16_t n_bytes_copied, uint8_t func_id, uint8_t ep_in, uint8_t cur_alt_setting) {
+  (void) rhport;
+  (void) n_bytes_copied;
+  (void) func_id;
+  (void) ep_in;
+  (void) cur_alt_setting;
+  return true;
+}
+#endif
+
+#if CFG_TUD_AUDIO_ENABLE_EP_OUT
+TU_ATTR_WEAK bool tud_audio_rx_done_pre_read_cb(uint8_t rhport, uint16_t n_bytes_received, uint8_t func_id, uint8_t ep_out, uint8_t cur_alt_setting) {
+  (void) rhport;
+  (void) n_bytes_received;
+  (void) func_id;
+  (void) ep_out;
+  (void) cur_alt_setting;
+  return true;
+}
+
+TU_ATTR_WEAK bool tud_audio_rx_done_post_read_cb(uint8_t rhport, uint16_t n_bytes_received, uint8_t func_id, uint8_t ep_out, uint8_t cur_alt_setting) {
+  (void) rhport;
+  (void) n_bytes_received;
+  (void) func_id;
+  (void) ep_out;
+  (void) cur_alt_setting;
+  return true;
+}
+#endif
+
+#if CFG_TUD_AUDIO_ENABLE_EP_OUT && CFG_TUD_AUDIO_ENABLE_FEEDBACK_EP
+TU_ATTR_WEAK void tud_audio_fb_done_cb(uint8_t func_id) {
+  (void) func_id;
+}
+
+TU_ATTR_WEAK void tud_audio_feedback_params_cb(uint8_t func_id, uint8_t alt_itf, audio_feedback_params_t* feedback_param) {
+  (void) func_id;
+  (void) 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;
+}
+#endif
+
+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;
+  (void) interval_shift;
+}
+
+#if CFG_TUD_AUDIO_ENABLE_INTERRUPT_EP
+TU_ATTR_WEAK void tud_audio_int_done_cb(uint8_t rhport) {
+  (void) rhport;
+}
+#endif
+
+// Invoked when audio set interface request received
+TU_ATTR_WEAK bool tud_audio_set_itf_cb(uint8_t rhport, tusb_control_request_t const * p_request) {
+  (void) rhport;
+  (void) p_request;
+  return true;
+}
+
+// Invoked when audio set interface request received which closes an EP
+TU_ATTR_WEAK bool tud_audio_set_itf_close_EP_cb(uint8_t rhport, tusb_control_request_t const * p_request) {
+  (void) rhport;
+  (void) p_request;
+  return true;
+}
+
+// Invoked when audio class specific set request received for an EP
+TU_ATTR_WEAK bool tud_audio_set_req_ep_cb(uint8_t rhport, tusb_control_request_t const * p_request, uint8_t *pBuff) {
+  (void) rhport;
+  (void) p_request;
+  (void) pBuff;
+  TU_LOG2("  No EP set request callback available!\r\n");
+  return false;   // In case no callback function is present or request can not be conducted we stall it
+}
+
+// Invoked when audio class specific set request received for an interface
+TU_ATTR_WEAK bool tud_audio_set_req_itf_cb(uint8_t rhport, tusb_control_request_t const * p_request, uint8_t *pBuff) {
+  (void) rhport;
+  (void) p_request;
+  (void) pBuff;
+  TU_LOG2("  No interface set request callback available!\r\n");
+  return false;   // In case no callback function is present or request can not be conducted we stall it
+}
+
+// Invoked when audio class specific set request received for an entity
+TU_ATTR_WEAK bool tud_audio_set_req_entity_cb(uint8_t rhport, tusb_control_request_t const * p_request, uint8_t *pBuff) {
+  (void) rhport;
+  (void) p_request;
+  (void) pBuff;
+  TU_LOG2("  No entity set request callback available!\r\n");
+  return false;   // In case no callback function is present or request can not be conducted we stall it
+}
+
+// Invoked when audio class specific get request received for an EP
+TU_ATTR_WEAK bool tud_audio_get_req_ep_cb(uint8_t rhport, tusb_control_request_t const * p_request) {
+  (void) rhport;
+  (void) p_request;
+  TU_LOG2("  No EP get request callback available!\r\n");
+  return false;   // Stall
+}
+
+// Invoked when audio class specific get request received for an interface
+TU_ATTR_WEAK bool tud_audio_get_req_itf_cb(uint8_t rhport, tusb_control_request_t const * p_request) {
+  (void) rhport;
+  (void) p_request;
+  TU_LOG2("  No interface get request callback available!\r\n");
+  return false;   // Stall
+}
+
+// Invoked when audio class specific get request received for an entity
+TU_ATTR_WEAK bool tud_audio_get_req_entity_cb(uint8_t rhport, tusb_control_request_t const * p_request) {
+  (void) rhport;
+  (void) p_request;
+  TU_LOG2("  No entity get request callback available!\r\n");
+  return false;   // Stall
+}
+
+//--------------------------------------------------------------------+
 // INTERNAL OBJECT & FUNCTION DECLARATION
 //--------------------------------------------------------------------+
-CFG_TUD_MEM_SECTION audiod_function_t _audiod_fct[CFG_TUD_AUDIO];
+tu_static CFG_TUD_MEM_SECTION audiod_function_t _audiod_fct[CFG_TUD_AUDIO];
 
 #if CFG_TUD_AUDIO_ENABLE_EP_OUT
 static bool audiod_rx_done_cb(uint8_t rhport, audiod_function_t* audio, uint16_t n_bytes_received);
@@ -473,7 +615,8 @@ static uint16_t audiod_tx_packet_size(const uint16_t* norminal_size, uint16_t da
 #endif
 
 #if CFG_TUD_AUDIO_ENABLE_EP_OUT && CFG_TUD_AUDIO_ENABLE_FEEDBACK_EP
-static bool set_fb_params_freq(audiod_function_t* audio, uint32_t sample_freq, uint32_t mclk_freq);
+static bool audiod_set_fb_params_freq(audiod_function_t* audio, uint32_t sample_freq, uint32_t mclk_freq);
+static void audiod_fb_fifo_count_update(audiod_function_t* audio, uint16_t lvl_new);
 #endif
 
 bool tud_audio_n_mounted(uint8_t func_id)
@@ -554,19 +697,13 @@ static bool audiod_rx_done_cb(uint8_t rhport, audiod_function_t* audio, uint16_t
   uint8_t const *dummy2;
   uint8_t idx_audio_fct = 0;
 
-  if (tud_audio_rx_done_pre_read_cb || tud_audio_rx_done_post_read_cb)
-  {
-    idx_audio_fct = audiod_get_audio_fct_idx(audio);
-    TU_VERIFY(audiod_get_AS_interface_index(audio->ep_out_as_intf_num, audio, &idxItf, &dummy2));
-  }
+  idx_audio_fct = audiod_get_audio_fct_idx(audio);
+  TU_VERIFY(audiod_get_AS_interface_index(audio->ep_out_as_intf_num, audio, &idxItf, &dummy2));
 
   // Call a weak callback here - a possibility for user to get informed an audio packet was received and data gets now loaded into EP FIFO (or decoded into support RX software FIFO)
-  if (tud_audio_rx_done_pre_read_cb)
-  {
-    TU_VERIFY(tud_audio_rx_done_pre_read_cb(rhport, n_bytes_received, idx_audio_fct, audio->ep_out, audio->alt_setting[idxItf]));
-  }
+  TU_VERIFY(tud_audio_rx_done_pre_read_cb(rhport, n_bytes_received, idx_audio_fct, audio->ep_out, audio->alt_setting[idxItf]));
 
-#if CFG_TUD_AUDIO_ENABLE_DECODING && CFG_TUD_AUDIO_ENABLE_EP_OUT
+#if CFG_TUD_AUDIO_ENABLE_DECODING
 
   switch (audio->format_type_rx)
   {
@@ -615,13 +752,17 @@ static bool audiod_rx_done_cb(uint8_t rhport, audiod_function_t* audio, uint16_t
   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
+  if(audio->feedback.compute_method == AUDIO_FEEDBACK_METHOD_FIFO_COUNT)
+  {
+    audiod_fb_fifo_count_update(audio, tu_fifo_count(&audio->ep_out_ff));
+  }
+#endif
+
 #endif
 
   // Call a weak callback here - a possibility for user to get informed decoding was completed
-  if (tud_audio_rx_done_post_read_cb)
-  {
-    TU_VERIFY(tud_audio_rx_done_post_read_cb(rhport, n_bytes_received, idx_audio_fct, audio->ep_out, audio->alt_setting[idxItf]));
-  }
+  TU_VERIFY(tud_audio_rx_done_post_read_cb(rhport, n_bytes_received, idx_audio_fct, audio->ep_out, audio->alt_setting[idxItf]));
 
   return true;
 }
@@ -707,16 +848,16 @@ static bool audiod_decode_type_I_pcm(uint8_t rhport, audiod_function_t* audio, u
     if (info.len_lin != 0)
     {
       info.len_lin = tu_min16(nBytesPerFFToRead, info.len_lin);
-      src = &audio->lin_buf_out[cnt_ff*audio->n_channels_per_ff_rx * audio->n_bytes_per_sampe_rx];
+      src = &audio->lin_buf_out[cnt_ff*audio->n_channels_per_ff_rx * audio->n_bytes_per_sample_rx];
       dst_end = info.ptr_lin + info.len_lin;
-      src = audiod_interleaved_copy_bytes_fast_decode(audio->n_bytes_per_sampe_rx, info.ptr_lin, dst_end, src, n_ff_used);
+      src = audiod_interleaved_copy_bytes_fast_decode(audio->n_bytes_per_sample_rx, info.ptr_lin, dst_end, src, n_ff_used);
 
       // Handle wrapped part of FIFO
       info.len_wrap = tu_min16(nBytesPerFFToRead - info.len_lin, info.len_wrap);
       if (info.len_wrap != 0)
       {
         dst_end = info.ptr_wrap + info.len_wrap;
-        audiod_interleaved_copy_bytes_fast_decode(audio->n_bytes_per_sampe_rx, info.ptr_wrap, dst_end, src, n_ff_used);
+        audiod_interleaved_copy_bytes_fast_decode(audio->n_bytes_per_sample_rx, info.ptr_wrap, dst_end, src, n_ff_used);
       }
       tu_fifo_advance_write_pointer(&audio->rx_supp_ff[cnt_ff], info.len_lin + info.len_wrap);
     }
@@ -725,6 +866,13 @@ static bool audiod_decode_type_I_pcm(uint8_t rhport, audiod_function_t* audio, u
   // Number of bytes should be a multiple of CFG_TUD_AUDIO_N_BYTES_PER_SAMPLE_RX * CFG_TUD_AUDIO_N_CHANNELS_RX but checking makes no sense - no way to correct it
   // TU_VERIFY(cnt != n_bytes);
 
+#if CFG_TUD_AUDIO_ENABLE_FEEDBACK_EP
+  if(audio->feedback.compute_method == AUDIO_FEEDBACK_METHOD_FIFO_COUNT)
+  {
+    audiod_fb_fifo_count_update(audio, tu_fifo_count(&audio->rx_supp_ff[0]));
+  }
+#endif
+
   return true;
 }
 #endif //CFG_TUD_AUDIO_ENABLE_DECODING
@@ -848,7 +996,7 @@ static bool audiod_tx_done_cb(uint8_t rhport, audiod_function_t * audio)
 
   // 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 (in case FIFOs are used) or
   // if no FIFOs are used the user may use this call back to load its data into the EP IN buffer by use of tud_audio_n_write_ep_in_buffer().
-  if (tud_audio_tx_done_pre_load_cb) TU_VERIFY(tud_audio_tx_done_pre_load_cb(rhport, idx_audio_fct, audio->ep_in, audio->alt_setting[idxItf]));
+  TU_VERIFY(tud_audio_tx_done_pre_load_cb(rhport, idx_audio_fct, audio->ep_in, audio->alt_setting[idxItf]));
 
   // Send everything in ISO EP FIFO
   uint16_t n_bytes_tx;
@@ -911,7 +1059,7 @@ static bool audiod_tx_done_cb(uint8_t rhport, audiod_function_t * audio)
 #endif
 
   // Call a weak callback here - a possibility for user to get informed former TX was completed and how many bytes were loaded for the next frame
-  if (tud_audio_tx_done_post_load_cb) TU_VERIFY(tud_audio_tx_done_post_load_cb(rhport, n_bytes_tx, idx_audio_fct, audio->ep_in, audio->alt_setting[idxItf]));
+  TU_VERIFY(tud_audio_tx_done_post_load_cb(rhport, n_bytes_tx, idx_audio_fct, audio->ep_in, audio->alt_setting[idxItf]));
 
   return true;
 }
@@ -1024,7 +1172,7 @@ static uint16_t audiod_encode_type_I_pcm(uint8_t rhport, audiod_function_t* audi
   // Limit to maximum sample number - THIS IS A POSSIBLE ERROR SOURCE IF TOO MANY SAMPLE WOULD NEED TO BE SENT BUT CAN NOT!
   nBytesPerFFToSend = tu_min16(nBytesPerFFToSend, audio->ep_in_sz / n_ff_used);
   // Round to full number of samples (flooring)
-  uint16_t const nSlotSize = audio->n_channels_per_ff_tx * audio->n_bytes_per_sampe_tx;
+  uint16_t const nSlotSize = audio->n_channels_per_ff_tx * audio->n_bytes_per_sample_tx;
   nBytesPerFFToSend = (nBytesPerFFToSend / nSlotSize) * nSlotSize;
 #endif
 
@@ -1036,7 +1184,7 @@ static uint16_t audiod_encode_type_I_pcm(uint8_t rhport, audiod_function_t* audi
 
   for (cnt_ff = 0; cnt_ff < n_ff_used; cnt_ff++)
   {
-    dst = &audio->lin_buf_in[cnt_ff*audio->n_channels_per_ff_tx*audio->n_bytes_per_sampe_tx];
+    dst = &audio->lin_buf_in[cnt_ff*audio->n_channels_per_ff_tx*audio->n_bytes_per_sample_tx];
 
     tu_fifo_get_read_info(&audio->tx_supp_ff[cnt_ff], &info);
 
@@ -1044,7 +1192,7 @@ static uint16_t audiod_encode_type_I_pcm(uint8_t rhport, audiod_function_t* audi
     {
       info.len_lin = tu_min16(nBytesPerFFToSend, info.len_lin);       // Limit up to desired length
       src_end = (uint8_t *)info.ptr_lin + info.len_lin;
-      dst = audiod_interleaved_copy_bytes_fast_encode(audio->n_bytes_per_sampe_tx, info.ptr_lin, src_end, dst, n_ff_used);
+      dst = audiod_interleaved_copy_bytes_fast_encode(audio->n_bytes_per_sample_tx, info.ptr_lin, src_end, dst, n_ff_used);
 
       // Limit up to desired length
       info.len_wrap = tu_min16(nBytesPerFFToSend - info.len_lin, info.len_wrap);
@@ -1053,7 +1201,7 @@ static uint16_t audiod_encode_type_I_pcm(uint8_t rhport, audiod_function_t* audi
       if (info.len_wrap != 0)
       {
         src_end = (uint8_t *)info.ptr_wrap + info.len_wrap;
-        audiod_interleaved_copy_bytes_fast_encode(audio->n_bytes_per_sampe_tx, info.ptr_wrap, src_end, dst, n_ff_used);
+        audiod_interleaved_copy_bytes_fast_encode(audio->n_bytes_per_sample_tx, info.ptr_wrap, src_end, dst, n_ff_used);
       }
 
       tu_fifo_advance_read_pointer(&audio->tx_supp_ff[cnt_ff], info.len_lin + info.len_wrap);
@@ -1067,9 +1215,38 @@ static uint16_t audiod_encode_type_I_pcm(uint8_t rhport, audiod_function_t* audi
 // This function is called once a transmit of a feedback packet was successfully completed. Here, we get the next feedback value to be sent
 
 #if CFG_TUD_AUDIO_ENABLE_EP_OUT && CFG_TUD_AUDIO_ENABLE_FEEDBACK_EP
-static inline bool audiod_fb_send(uint8_t rhport, audiod_function_t *audio)
+static inline bool audiod_fb_send(audiod_function_t *audio)
 {
-  return usbd_edpt_xfer(rhport, audio->ep_fb, (uint8_t *) &audio->feedback.value, 4);
+  bool apply_correction = (TUSB_SPEED_FULL == tud_speed_get()) && audio->feedback.format_correction;
+  // Format the feedback value
+  if (apply_correction)
+  {
+    uint8_t * fb = (uint8_t *) &audio->feedback.send_buf;
+
+    // For FS format is 10.14
+    *(fb++) = (audio->feedback.value >> 2) & 0xFF;
+    *(fb++) = (audio->feedback.value >> 10) & 0xFF;
+    *(fb++) = (audio->feedback.value >> 18) & 0xFF;
+    *fb = 0;
+  } else
+  {
+    audio->feedback.send_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->feedback.send_buf, apply_correction ? 3 : 4);
 }
 #endif
 
@@ -1490,7 +1667,8 @@ uint16_t audiod_open(uint8_t rhport, tusb_desc_interface_t const * itf_desc, uin
   #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;
-        while (p_desc < p_desc_end)
+        // 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)
           {
@@ -1686,7 +1864,7 @@ static bool audiod_set_interface(uint8_t rhport, tusb_control_request_t const *
   #endif
 
     // Invoke callback - can be used to stop data sampling
-    if (tud_audio_set_itf_close_EP_cb) TU_VERIFY(tud_audio_set_itf_close_EP_cb(rhport, p_request));
+    TU_VERIFY(tud_audio_set_itf_close_EP_cb(rhport, p_request));
 
     audio->ep_in = 0;                           // Necessary?
 
@@ -1717,7 +1895,7 @@ static bool audiod_set_interface(uint8_t rhport, tusb_control_request_t const *
   #endif
 
     // Invoke callback - can be used to stop data sampling
-    if (tud_audio_set_itf_close_EP_cb) TU_VERIFY(tud_audio_set_itf_close_EP_cb(rhport, p_request));
+    TU_VERIFY(tud_audio_set_itf_close_EP_cb(rhport, p_request));
 
     audio->ep_out = 0;                          // Necessary?
 
@@ -1740,7 +1918,8 @@ static bool audiod_set_interface(uint8_t rhport, tusb_control_request_t const *
   uint8_t const *p_desc_end = audio->p_desc + audio->desc_length - TUD_AUDIO_DESC_IAD_LEN;
 
   // p_desc starts at required interface with alternate setting zero
-  while (p_desc < p_desc_end)
+  // Condition modified from p_desc < p_desc_end to prevent gcc>=12 strict-overflow warning
+  while (p_desc_end - p_desc > 0)
   {
     // Find correct interface
     if (tu_desc_type(p_desc) == TUSB_DESC_INTERFACE && ((tusb_desc_interface_t const * )p_desc)->bInterfaceNumber == itf && ((tusb_desc_interface_t const * )p_desc)->bAlternateSetting == alt)
@@ -1750,7 +1929,8 @@ static bool audiod_set_interface(uint8_t rhport, tusb_control_request_t const *
 #endif
       // From this point forward follow the EP descriptors associated to the current alternate setting interface - Open EPs if necessary
       uint8_t foundEPs = 0, nEps = ((tusb_desc_interface_t const * )p_desc)->bNumEndpoints;
-      while (foundEPs < nEps && p_desc < p_desc_end)
+      // Condition modified from p_desc < p_desc_end to prevent gcc>=12 strict-overflow warning
+      while (foundEPs < nEps && (p_desc_end - p_desc > 0))
       {
         if (tu_desc_type(p_desc) == TUSB_DESC_ENDPOINT)
         {
@@ -1779,8 +1959,8 @@ static bool audiod_set_interface(uint8_t rhport, tusb_control_request_t const *
 
             // Reconfigure size of support FIFOs - this is necessary to avoid samples to get split in case of a wrap
     #if CFG_TUD_AUDIO_ENABLE_ENCODING && CFG_TUD_AUDIO_ENABLE_TYPE_I_ENCODING
-            const uint16_t active_fifo_depth = (uint16_t) ((audio->tx_supp_ff_sz_max / (audio->n_channels_per_ff_tx * audio->n_bytes_per_sampe_tx))
-               * (audio->n_channels_per_ff_tx * audio->n_bytes_per_sampe_tx));
+            const uint16_t active_fifo_depth = (uint16_t) ((audio->tx_supp_ff_sz_max / (audio->n_channels_per_ff_tx * audio->n_bytes_per_sample_tx))
+               * (audio->n_channels_per_ff_tx * audio->n_bytes_per_sample_tx));
             for (uint8_t cnt = 0; cnt < audio->n_tx_supp_ff; cnt++)
             {
               tu_fifo_config(&audio->tx_supp_ff[cnt], audio->tx_supp_ff[cnt].buffer, active_fifo_depth, 1, true);
@@ -1810,7 +1990,7 @@ static bool audiod_set_interface(uint8_t rhport, tusb_control_request_t const *
 
             // Reconfigure size of support FIFOs - this is necessary to avoid samples to get split in case of a wrap
     #if CFG_TUD_AUDIO_ENABLE_TYPE_I_DECODING
-            const uint16_t active_fifo_depth = (audio->rx_supp_ff_sz_max / audio->n_bytes_per_sampe_rx) * audio->n_bytes_per_sampe_rx;
+            const uint16_t active_fifo_depth = (audio->rx_supp_ff_sz_max / audio->n_bytes_per_sample_rx) * audio->n_bytes_per_sample_rx;
             for (uint8_t cnt = 0; cnt < audio->n_rx_supp_ff; cnt++)
             {
               tu_fifo_config(&audio->rx_supp_ff[cnt], audio->rx_supp_ff[cnt].buffer, active_fifo_depth, 1, true);
@@ -1833,9 +2013,6 @@ static bool audiod_set_interface(uint8_t rhport, tusb_control_request_t const *
           {
             audio->ep_fb = ep_addr;
             audio->feedback.frame_shift = desc_ep->bInterval -1;
-
-            // Enable SOF interrupt if callback is implemented
-            if (tud_audio_feedback_interval_isr) usbd_sof_enable(rhport, true);
           }
   #endif
 #endif // CFG_TUD_AUDIO_ENABLE_EP_OUT
@@ -1848,20 +2025,23 @@ static bool audiod_set_interface(uint8_t rhport, tusb_control_request_t const *
       TU_VERIFY(foundEPs == nEps);
 
       // Invoke one callback for a final set interface
-      if (tud_audio_set_itf_cb) TU_VERIFY(tud_audio_set_itf_cb(rhport, p_request));
+      TU_VERIFY(tud_audio_set_itf_cb(rhport, p_request));
 
 #if CFG_TUD_AUDIO_ENABLE_FEEDBACK_EP
-      // Prepare feedback computation if callback is available
-      if (tud_audio_feedback_params_cb)
+      // 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/frame_div - 1) << 16;
+        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)
@@ -1869,20 +2049,32 @@ static bool audiod_set_interface(uint8_t rhport, tusb_control_request_t const *
           case AUDIO_FEEDBACK_METHOD_FREQUENCY_FIXED:
           case AUDIO_FEEDBACK_METHOD_FREQUENCY_FLOAT:
           case AUDIO_FEEDBACK_METHOD_FREQUENCY_POWER_OF_2:
-            set_fb_params_freq(audio, fb_param.sample_freq, fb_param.frequency.mclk_freq);
+            audiod_set_fb_params_freq(audio, fb_param.sample_freq, fb_param.frequency.mclk_freq);
           break;
 
-          #if 0 // implement later
           case AUDIO_FEEDBACK_METHOD_FIFO_COUNT:
           {
-            uint64_t fb64 = ((uint64_t) fb_param.sample_freq) << 16;
-            audio->feedback.compute.fifo_count.nominal_value = (uint32_t) (fb64 / frame_div);
-            audio->feedback.compute.fifo_count.threshold_bytes = fb_param.fifo_count.threshold_bytes;
-
-            tud_audio_fb_set(audio->feedback.compute.fifo_count.nominal_value);
+            // Initialize the threshold level to half filled
+            uint16_t fifo_lvl_thr;
+#if CFG_TUD_AUDIO_ENABLE_DECODING
+            fifo_lvl_thr = tu_fifo_depth(&audio->rx_supp_ff[0]) / 2;
+#else
+            fifo_lvl_thr = tu_fifo_depth(&audio->ep_out_ff) / 2;
+#endif
+            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;
-          #endif
 
           // nothing to do
           default: break;
@@ -1900,16 +2092,19 @@ static bool audiod_set_interface(uint8_t rhport, tusb_control_request_t const *
 
 #if CFG_TUD_AUDIO_ENABLE_FEEDBACK_EP
   // Disable SOF interrupt if no driver has any enabled feedback EP
-  bool disable = true;
+  bool enable_sof = false;
   for(uint8_t i=0; i < CFG_TUD_AUDIO; i++)
   {
-    if (_audiod_fct[i].ep_fb != 0)
+    if (_audiod_fct[i].ep_fb != 0 &&
+      (_audiod_fct[i].feedback.compute_method == AUDIO_FEEDBACK_METHOD_FREQUENCY_FIXED ||
+       _audiod_fct[i].feedback.compute_method == AUDIO_FEEDBACK_METHOD_FREQUENCY_FLOAT ||
+       _audiod_fct[i].feedback.compute_method == AUDIO_FEEDBACK_METHOD_FREQUENCY_POWER_OF_2 ))
     {
-      disable = false;
+      enable_sof = true;
       break;
     }
   }
-  if (disable) usbd_sof_enable(rhport, false);
+  usbd_sof_enable(rhport, SOF_CONSUMER_AUDIO, enable_sof);
 #endif
 
 #if CFG_TUD_AUDIO_ENABLE_EP_IN && CFG_TUD_AUDIO_EP_IN_FLOW_CONTROL
@@ -1939,35 +2134,19 @@ static bool audiod_control_complete(uint8_t rhport, tusb_control_request_t const
 
         if (entityID != 0)
         {
-          if (tud_audio_set_req_entity_cb)
-          {
-            // Check if entity is present and get corresponding driver index
-            TU_VERIFY(audiod_verify_entity_exists(itf, entityID, &func_id));
+          // Check if entity is present and get corresponding driver index
+          TU_VERIFY(audiod_verify_entity_exists(itf, entityID, &func_id));
 
-            // Invoke callback
-            return tud_audio_set_req_entity_cb(rhport, p_request, _audiod_fct[func_id].ctrl_buf);
-          }
-          else
-          {
-            TU_LOG2("  No entity set request callback available!\r\n");
-            return false;     // In case no callback function is present or request can not be conducted we stall it
-          }
+          // Invoke callback
+          return tud_audio_set_req_entity_cb(rhport, p_request, _audiod_fct[func_id].ctrl_buf);
         }
         else
         {
-          if (tud_audio_set_req_itf_cb)
-          {
-            // Find index of audio driver structure and verify interface really exists
-            TU_VERIFY(audiod_verify_itf_exists(itf, &func_id));
+          // 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);
-          }
-          else
-          {
-            TU_LOG2("  No interface set request callback available!\r\n");
-            return false;     // In case no callback function is present or request can not be conducted we stall it
-          }
+          // Invoke callback
+          return tud_audio_set_req_itf_cb(rhport, p_request, _audiod_fct[func_id].ctrl_buf);
         }
       }
       break;
@@ -1976,19 +2155,11 @@ static bool audiod_control_complete(uint8_t rhport, tusb_control_request_t const
       {
         uint8_t ep = TU_U16_LOW(p_request->wIndex);
 
-        if (tud_audio_set_req_ep_cb)
-        {
-          // Check if entity is present and get corresponding driver index
-          TU_VERIFY(audiod_verify_ep_exists(ep, &func_id));
+        // 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);
-        }
-        else
-        {
-          TU_LOG2("  No EP set request callback available!\r\n");
-          return false;   // In case no callback function is present or request can not be conducted we stall it
-        }
+        // Invoke callback
+        return tud_audio_set_req_ep_cb(rhport, p_request, _audiod_fct[func_id].ctrl_buf);
       }
       break;
       // Unknown/Unsupported recipient
@@ -2045,15 +2216,7 @@ static bool audiod_control_request(uint8_t rhport, tusb_control_request_t const
           // In case we got a get request invoke callback - callback needs to answer as defined in UAC2 specification page 89 - 5. Requests
           if (p_request->bmRequestType_bit.direction == TUSB_DIR_IN)
           {
-            if (tud_audio_get_req_entity_cb)
-            {
-              return tud_audio_get_req_entity_cb(rhport, p_request);
-            }
-            else
-            {
-              TU_LOG2("  No entity get request callback available!\r\n");
-              return false;   // Stall
-            }
+            return tud_audio_get_req_entity_cb(rhport, p_request);
           }
         }
         else
@@ -2064,15 +2227,7 @@ static bool audiod_control_request(uint8_t rhport, tusb_control_request_t const
           // In case we got a get request invoke callback - callback needs to answer as defined in UAC2 specification page 89 - 5. Requests
           if (p_request->bmRequestType_bit.direction == TUSB_DIR_IN)
           {
-            if (tud_audio_get_req_itf_cb)
-            {
-              return tud_audio_get_req_itf_cb(rhport, p_request);
-            }
-            else
-            {
-              TU_LOG2("  No interface get request callback available!\r\n");
-              return false;   // Stall
-            }
+            return tud_audio_get_req_itf_cb(rhport, p_request);
           }
         }
       }
@@ -2088,15 +2243,7 @@ static bool audiod_control_request(uint8_t rhport, tusb_control_request_t const
         // In case we got a get request invoke callback - callback needs to answer as defined in UAC2 specification page 89 - 5. Requests
         if (p_request->bmRequestType_bit.direction == TUSB_DIR_IN)
         {
-          if (tud_audio_get_req_ep_cb)
-          {
-            return tud_audio_get_req_ep_cb(rhport, p_request);
-          }
-          else
-          {
-            TU_LOG2("  No EP get request callback available!\r\n");
-            return false;     // Stall
-          }
+          return tud_audio_get_req_ep_cb(rhport, p_request);
         }
       }
       break;
@@ -2151,7 +2298,7 @@ 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
 
-      if (tud_audio_int_done_cb) tud_audio_int_done_cb(rhport);
+      tud_audio_int_done_cb(rhport);
       return true;
     }
 
@@ -2192,13 +2339,13 @@ bool audiod_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint3
     // Transmission of feedback EP finished
     if (audio->ep_fb == ep_addr)
     {
-      if (tud_audio_fb_done_cb) tud_audio_fb_done_cb(func_id);
+      tud_audio_fb_done_cb(func_id);
 
       // Schedule a transmit with the new value if EP is not busy
-      if (!usbd_edpt_busy(rhport, audio->ep_fb))
+      if (usbd_edpt_claim(rhport, audio->ep_fb))
       {
         // Schedule next transmission - value is changed bytud_audio_n_fb_set() in the meantime or the old value gets sent
-        return audiod_fb_send(rhport, audio);
+        return audiod_fb_send(audio);
       }
     }
 #endif
@@ -2210,7 +2357,7 @@ bool audiod_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint3
 
 #if CFG_TUD_AUDIO_ENABLE_EP_OUT && CFG_TUD_AUDIO_ENABLE_FEEDBACK_EP
 
-static bool set_fb_params_freq(audiod_function_t* audio, uint32_t sample_freq, uint32_t mclk_freq)
+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()
@@ -2229,11 +2376,11 @@ static bool set_fb_params_freq(audiod_function_t* audio, uint32_t sample_freq, u
   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 = 16 - audio->feedback.frame_shift - tu_log2(mclk_freq / sample_freq);
+    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 / mclk_freq * (1UL << (16 - audio->feedback.frame_shift));
+    audio->feedback.compute.float_const = (float)sample_freq / (float) mclk_freq * (1UL << (16 - (audio->feedback.frame_shift - 1)));
   }
   else
   {
@@ -2244,6 +2391,38 @@ static bool set_fb_params_freq(audiod_function_t* audio, uint32_t sample_freq, u
   return true;
 }
 
+static void audiod_fb_fifo_count_update(audiod_function_t* audio, uint16_t lvl_new)
+{
+  /* Low-pass (averaging) filter */
+  uint32_t lvl = audio->feedback.compute.fifo_count.fifo_lvl_avg;
+  lvl = (uint32_t)(((uint64_t)lvl * 63  + ((uint32_t)lvl_new << 16)) >> 6);
+  audio->feedback.compute.fifo_count.fifo_lvl_avg = lvl;
+
+  uint32_t const ff_lvl = lvl >> 16;
+  uint16_t const ff_thr = audio->feedback.compute.fifo_count.fifo_lvl_thr;
+  uint16_t const *rate   = audio->feedback.compute.fifo_count.rate_const;
+
+  uint32_t feedback;
+
+  if(ff_lvl < ff_thr)
+  {
+    feedback = audio->feedback.compute.fifo_count.nom_value + (ff_thr - ff_lvl) * rate[0];
+  } else
+  {
+    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;
+
+  // Schedule a transmit with the new value if EP is not busy - this triggers repetitive scheduling of the feedback value
+  if (usbd_edpt_claim(audio->rhport, audio->ep_fb))
+  {
+    audiod_fb_send(audio);
+  }
+}
+
 uint32_t tud_audio_feedback_update(uint8_t func_id, uint32_t cycles)
 {
   audiod_function_t* audio = &_audiod_fct[func_id];
@@ -2261,7 +2440,7 @@ uint32_t tud_audio_feedback_update(uint8_t func_id, uint32_t cycles)
 
     case AUDIO_FEEDBACK_METHOD_FREQUENCY_FIXED:
     {
-      uint64_t fb64 = (((uint64_t) cycles) * audio->feedback.compute.fixed.sample_freq) << (16 - audio->feedback.frame_shift);
+      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;
@@ -2280,6 +2459,21 @@ uint32_t tud_audio_feedback_update(uint8_t func_id, uint32_t cycles)
 
   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;
+
+  // Schedule a transmit with the new value if EP is not busy - this triggers repetitive scheduling of the feedback value
+  if (usbd_edpt_claim(_audiod_fct[func_id].rhport, _audiod_fct[func_id].ep_fb))
+  {
+    return audiod_fb_send(&_audiod_fct[func_id]);
+  }
+
+  return true;
+}
 #endif
 
 TU_ATTR_FAST_FUNC void audiod_sof_isr (uint8_t rhport, uint32_t frame_count)
@@ -2306,7 +2500,7 @@ TU_ATTR_FAST_FUNC void audiod_sof_isr (uint8_t rhport, uint32_t frame_count)
       uint32_t const interval = 1UL << (audio->feedback.frame_shift - hs_adjust);
       if ( 0 == (frame_count & (interval-1)) )
       {
-        if(tud_audio_feedback_interval_isr) tud_audio_feedback_interval_isr(i, frame_count, audio->feedback.frame_shift);
+        tud_audio_feedback_interval_isr(i, frame_count, audio->feedback.frame_shift);
       }
     }
   }
@@ -2394,7 +2588,8 @@ static bool audiod_get_AS_interface_index(uint8_t itf, audiod_function_t * audio
     p_desc += ((audio_desc_cs_ac_interface_t const *)p_desc)->wTotalLength;
 
     uint8_t tmp = 0;
-    while (p_desc < p_desc_end)
+    // Condition modified from p_desc < p_desc_end to prevent gcc>=12 strict-overflow warning
+    while (p_desc_end - p_desc > 0)
     {
       // We assume the number of alternate settings is increasing thus we return the index of alternate setting zero!
       if (tu_desc_type(p_desc) == TUSB_DESC_INTERFACE && ((tusb_desc_interface_t const * )p_desc)->bAlternateSetting == 0)
@@ -2447,7 +2642,8 @@ static bool audiod_verify_entity_exists(uint8_t itf, uint8_t entityID, uint8_t *
       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
 
-      while (p_desc < p_desc_end)
+      // Condition modified from p_desc < p_desc_end to prevent gcc>=12 strict-overflow warning
+      while (p_desc_end - p_desc > 0)
       {
         if (p_desc[3] == entityID)  // Entity IDs are always at offset 3
         {
@@ -2471,8 +2667,8 @@ static bool audiod_verify_itf_exists(uint8_t itf, uint8_t *func_id)
       // 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;
-
-      while (p_desc < p_desc_end)
+      // 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 *)_audiod_fct[i].p_desc)->bInterfaceNumber == itf)
         {
@@ -2500,7 +2696,8 @@ static bool audiod_verify_ep_exists(uint8_t ep, uint8_t *func_id)
       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;
 
-      while (p_desc < p_desc_end)
+      // 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 * )p_desc)->bEndpointAddress == ep)
         {
@@ -2531,8 +2728,8 @@ static void audiod_parse_for_AS_params(audiod_function_t* audio, uint8_t const *
 #endif
 
   p_desc = tu_desc_next(p_desc);    // Exclude standard AS interface descriptor of current alternate interface descriptor
-
-  while (p_desc < p_desc_end)
+  // Condition modified from p_desc < p_desc_end to prevent gcc>=12 strict-overflow warning
+  while (p_desc_end - p_desc > 0)
   {
     // Abort if follow up descriptor is a new standard interface descriptor - indicates the last AS descriptor was already finished
     if (tu_desc_type(p_desc) == TUSB_DESC_INTERFACE) break;
@@ -2581,14 +2778,14 @@ static void audiod_parse_for_AS_params(audiod_function_t* audio, uint8_t const *
 #if CFG_TUD_AUDIO_ENABLE_EP_IN
       if (as_itf == audio->ep_in_as_intf_num)
       {
-        audio->n_bytes_per_sampe_tx = ((audio_desc_type_I_format_t const * )p_desc)->bSubslotSize;
+        audio->n_bytes_per_sample_tx = ((audio_desc_type_I_format_t const * )p_desc)->bSubslotSize;
       }
 #endif
 
 #if CFG_TUD_AUDIO_ENABLE_EP_OUT && CFG_TUD_AUDIO_ENABLE_DECODING
       if (as_itf == audio->ep_out_as_intf_num)
       {
-        audio->n_bytes_per_sampe_rx = ((audio_desc_type_I_format_t const * )p_desc)->bSubslotSize;
+        audio->n_bytes_per_sample_rx = ((audio_desc_type_I_format_t const * )p_desc)->bSubslotSize;
       }
 #endif
     }
@@ -2607,7 +2804,7 @@ static bool audiod_calc_tx_packet_sz(audiod_function_t* audio)
 {
   TU_VERIFY(audio->format_type_tx == AUDIO_FORMAT_TYPE_I);
   TU_VERIFY(audio->n_channels_tx);
-  TU_VERIFY(audio->n_bytes_per_sampe_tx);
+  TU_VERIFY(audio->n_bytes_per_sample_tx);
   TU_VERIFY(audio->interval_tx);
   TU_VERIFY(audio->sample_rate_tx);
 
@@ -2616,9 +2813,9 @@ static bool audiod_calc_tx_packet_sz(audiod_function_t* audio)
   const uint16_t sample_normimal = (uint16_t)(audio->sample_rate_tx * interval / ((tud_speed_get() == TUSB_SPEED_FULL) ? 1000 : 8000));
   const uint16_t sample_reminder = (uint16_t)(audio->sample_rate_tx * interval % ((tud_speed_get() == TUSB_SPEED_FULL) ? 1000 : 8000));
 
-  const uint16_t packet_sz_tx_min = (uint16_t)((sample_normimal - 1) * audio->n_channels_tx * audio->n_bytes_per_sampe_tx);
-  const uint16_t packet_sz_tx_norm = (uint16_t)(sample_normimal * audio->n_channels_tx * audio->n_bytes_per_sampe_tx);
-  const uint16_t packet_sz_tx_max = (uint16_t)((sample_normimal + 1) * audio->n_channels_tx * audio->n_bytes_per_sampe_tx);
+  const uint16_t packet_sz_tx_min = (uint16_t)((sample_normimal - 1) * audio->n_channels_tx * audio->n_bytes_per_sample_tx);
+  const uint16_t packet_sz_tx_norm = (uint16_t)(sample_normimal * audio->n_channels_tx * audio->n_bytes_per_sample_tx);
+  const uint16_t packet_sz_tx_max = (uint16_t)((sample_normimal + 1) * audio->n_channels_tx * audio->n_bytes_per_sample_tx);
 
   // Endpoint size must larger than packet size
   TU_ASSERT(packet_sz_tx_max <= audio->ep_in_sz);
@@ -2691,44 +2888,8 @@ static uint16_t audiod_tx_packet_size(const uint16_t* norminal_size, uint16_t da
 
 #endif
 
-#if CFG_TUD_AUDIO_ENABLE_FEEDBACK_EP
-
-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);
-
-  // Format the feedback value
-#if CFG_TUD_AUDIO_ENABLE_FEEDBACK_FORMAT_CORRECTION
-  if ( TUSB_SPEED_FULL == tud_speed_get() )
-  {
-    uint8_t * fb = (uint8_t *) &_audiod_fct[func_id].feedback.value;
-
-    // For FS format is 10.14
-    *(fb++) = (feedback >> 2) & 0xFF;
-    *(fb++) = (feedback >> 10) & 0xFF;
-    *(fb++) = (feedback >> 18) & 0xFF;
-    // 4th byte is needed to work correctly with MS Windows
-    *fb = 0;
-  }else
-#else
-  {
-    // Send value as-is, caller will choose the appropriate format
-    _audiod_fct[func_id].feedback.value = feedback;
-  }
-#endif
-
-  // Schedule a transmit with the new value if EP is not busy - this triggers repetitive scheduling of the feedback value
-  if (!usbd_edpt_busy(_audiod_fct[func_id].rhport, _audiod_fct[func_id].ep_fb))
-  {
-    return audiod_fb_send(_audiod_fct[func_id].rhport, &_audiod_fct[func_id]);
-  }
-
-  return true;
-}
-#endif
-
 // No security checks here - internal function only which should always succeed
-uint8_t audiod_get_audio_fct_idx(audiod_function_t * audio)
+static uint8_t audiod_get_audio_fct_idx(audiod_function_t * audio)
 {
   for (uint8_t cnt=0; cnt < CFG_TUD_AUDIO; cnt++)
   {
diff --git a/src/class/audio/audio_device.h b/src/class/audio/audio_device.h
index b16514fd4..ae253f49d 100644
--- a/src/class/audio/audio_device.h
+++ b/src/class/audio/audio_device.h
@@ -3,6 +3,7 @@
  *
  * Copyright (c) 2020 Ha Thach (tinyusb.org)
  * Copyright (c) 2020 Reinhard Panhuber
+ * Copyright (c) 2023 HiFiPhile
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -192,6 +193,7 @@
 #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
@@ -242,7 +244,8 @@
 // Enable encoding/decodings - for these to work, support FIFOs need to be setup in appropriate numbers and size
 // The actual coding parameters of active AS alternate interface is parsed from the descriptors
 
-// The item size of the FIFO is always fixed to one i.e. bytes! Furthermore, the actively used FIFO depth is reconfigured such that the depth is a multiple of the current sample size in order to avoid samples to get split up in case of a wrap in the FIFO ring buffer (depth = (max_depth / sampe_sz) * sampe_sz)!
+// The item size of the FIFO is always fixed to one i.e. bytes! Furthermore, the actively used FIFO depth is reconfigured such that the depth is a multiple
+// of the current sample size in order to avoid samples to get split up in case of a wrap in the FIFO ring buffer (depth = (max_depth / sample_sz) * sample_sz)!
 // This is important to remind in case you use DMAs! If the sample sizes changes, the DMA MUST BE RECONFIGURED just like the FIFOs for a different depth!!!
 
 // For PCM encoding/decoding
@@ -446,63 +449,80 @@ static inline bool tud_audio_int_write                      (const audio_interru
 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 (weak is optional)
+// Application Callback API
 //--------------------------------------------------------------------+
 
 #if CFG_TUD_AUDIO_ENABLE_EP_IN
-TU_ATTR_WEAK bool tud_audio_tx_done_pre_load_cb(uint8_t rhport, uint8_t func_id, uint8_t ep_in, uint8_t cur_alt_setting);
-TU_ATTR_WEAK bool tud_audio_tx_done_post_load_cb(uint8_t rhport, uint16_t n_bytes_copied, uint8_t func_id, uint8_t ep_in, uint8_t cur_alt_setting);
+bool tud_audio_tx_done_pre_load_cb(uint8_t rhport, uint8_t func_id, uint8_t ep_in, uint8_t cur_alt_setting);
+bool tud_audio_tx_done_post_load_cb(uint8_t rhport, uint16_t n_bytes_copied, uint8_t func_id, uint8_t ep_in, uint8_t cur_alt_setting);
 #endif
 
 #if CFG_TUD_AUDIO_ENABLE_EP_OUT
-TU_ATTR_WEAK bool tud_audio_rx_done_pre_read_cb(uint8_t rhport, uint16_t n_bytes_received, uint8_t func_id, uint8_t ep_out, uint8_t cur_alt_setting);
-TU_ATTR_WEAK bool tud_audio_rx_done_post_read_cb(uint8_t rhport, uint16_t n_bytes_received, uint8_t func_id, uint8_t ep_out, uint8_t cur_alt_setting);
+bool tud_audio_rx_done_pre_read_cb(uint8_t rhport, uint16_t n_bytes_received, uint8_t func_id, uint8_t ep_out, uint8_t cur_alt_setting);
+bool tud_audio_rx_done_post_read_cb(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
-TU_ATTR_WEAK void tud_audio_fb_done_cb(uint8_t func_id);
+void tud_audio_fb_done_cb(uint8_t func_id);
 
 
-// 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. 8 frames), i.e. a larger delay is introduced.
-
-// 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(). Advantage: Reduced jitter in the feedback value computation, hence, the receive FIFO can be smaller (e.g. 2 frames) and thus a smaller delay is possible, disadvantage: higher CPU load due to SOF ISR handling every frame i.e. 1ms or 125us. This option is a great starting point to try the SOF ISR option but depending on your hardware setup (performance of the CPU) it might not work. If so, figure out why and use the next option. (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).
+// Note about feedback calculation
+//
+// 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.
+//
+// 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).
+// 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.
+//
+// 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.
 
-// Feedback value is determined by the user by use of SOF interrupt. The user may use tud_audio_sof_isr() which is called every SOF (of course only invoked when an alternate interface other than zero was set). The number of frames used to determine the feedback value for the currently active alternate setting can be get by tud_audio_get_fb_n_frames(). The feedback value must be set by use of tud_audio_n_fb_set().
 
 // 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, then tinyusb
-// expects 16.16 format and handles the conversion to 10.14 on FS.
+// 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.
+//
+// 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 macOS it seems the
-// driver can work with either format. So a good compromise is to keep format correction disabled and stick to 16.16 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.
-
+//
 // 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)
+// 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);
-static inline bool tud_audio_fb_set(uint32_t feedback);
 
-// Update feedback value with passed cycles since last time this update function is called.
+// Update feedback value with passed MCLK cycles since last time this update function is called.
 // Typically called within tud_audio_sof_isr(). Required tud_audio_feedback_params_cb() is implemented
 // This function will also call tud_audio_feedback_set()
 // return feedback value in 16.16 for reference (0 for error)
+// Example :
+//   binterval=3 (4ms); FS = 48kHz; MCLK = 12.288MHz
+//   In 4 SOF MCLK counted 49152 cycles
 uint32_t tud_audio_feedback_update(uint8_t func_id, uint32_t cycles);
 
 enum {
   AUDIO_FEEDBACK_METHOD_DISABLED,
   AUDIO_FEEDBACK_METHOD_FREQUENCY_FIXED,
   AUDIO_FEEDBACK_METHOD_FREQUENCY_FLOAT,
-  AUDIO_FEEDBACK_METHOD_FREQUENCY_POWER_OF_2,
-
-  // impelemnt later
-  // AUDIO_FEEDBACK_METHOD_FIFO_COUNT
+  AUDIO_FEEDBACK_METHOD_FREQUENCY_POWER_OF_2, // For driver internal use only
+  AUDIO_FEEDBACK_METHOD_FIFO_COUNT
 };
 
 typedef struct {
@@ -514,52 +534,50 @@ typedef struct {
       uint32_t mclk_freq; // Main clock frequency in Hz i.e. master clock to which sample clock is based on
     }frequency;
 
-#if 0 // implement later
-    struct {
-      uint32_t threshold_bytes; // minimum number of bytes received to be considered as filled/ready
-    }fifo_count;
-#endif
   };
 }audio_feedback_params_t;
 
 // Invoked when needed to set feedback parameters
-TU_ATTR_WEAK void tud_audio_feedback_params_cb(uint8_t func_id, uint8_t alt_itf, audio_feedback_params_t* feedback_param);
+void tud_audio_feedback_params_cb(uint8_t func_id, uint8_t alt_itf, audio_feedback_params_t* feedback_param);
 
 // Callback in ISR context, invoked periodically according to feedback endpoint bInterval.
 // Could be used to compute and update feedback value, should be placed in RAM if possible
 // frame_number  : current SOF count
 // interval_shift: number of bit shift i.e log2(interval) from Feedback endpoint descriptor
-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);
+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
-TU_ATTR_WEAK void tud_audio_int_done_cb(uint8_t rhport);
+void tud_audio_int_done_cb(uint8_t rhport);
 #endif
 
 // Invoked when audio set interface request received
-TU_ATTR_WEAK bool tud_audio_set_itf_cb(uint8_t rhport, tusb_control_request_t const * p_request);
+bool tud_audio_set_itf_cb(uint8_t rhport, tusb_control_request_t const * p_request);
 
 // Invoked when audio set interface request received which closes an EP
-TU_ATTR_WEAK bool tud_audio_set_itf_close_EP_cb(uint8_t rhport, tusb_control_request_t const * p_request);
+bool tud_audio_set_itf_close_EP_cb(uint8_t rhport, tusb_control_request_t const * p_request);
 
 // Invoked when audio class specific set request received for an EP
-TU_ATTR_WEAK bool tud_audio_set_req_ep_cb(uint8_t rhport, tusb_control_request_t const * p_request, uint8_t *pBuff);
+bool tud_audio_set_req_ep_cb(uint8_t rhport, tusb_control_request_t const * p_request, uint8_t *pBuff);
 
 // Invoked when audio class specific set request received for an interface
-TU_ATTR_WEAK bool tud_audio_set_req_itf_cb(uint8_t rhport, tusb_control_request_t const * p_request, uint8_t *pBuff);
+bool tud_audio_set_req_itf_cb(uint8_t rhport, tusb_control_request_t const * p_request, uint8_t *pBuff);
 
 // Invoked when audio class specific set request received for an entity
-TU_ATTR_WEAK bool tud_audio_set_req_entity_cb(uint8_t rhport, tusb_control_request_t const * p_request, uint8_t *pBuff);
+bool tud_audio_set_req_entity_cb(uint8_t rhport, tusb_control_request_t const * p_request, uint8_t *pBuff);
 
 // Invoked when audio class specific get request received for an EP
-TU_ATTR_WEAK bool tud_audio_get_req_ep_cb(uint8_t rhport, tusb_control_request_t const * p_request);
+bool tud_audio_get_req_ep_cb(uint8_t rhport, tusb_control_request_t const * p_request);
 
 // Invoked when audio class specific get request received for an interface
-TU_ATTR_WEAK bool tud_audio_get_req_itf_cb(uint8_t rhport, tusb_control_request_t const * p_request);
+bool tud_audio_get_req_itf_cb(uint8_t rhport, tusb_control_request_t const * p_request);
 
 // Invoked when audio class specific get request received for an entity
-TU_ATTR_WEAK bool tud_audio_get_req_entity_cb(uint8_t rhport, tusb_control_request_t const * p_request);
+bool tud_audio_get_req_entity_cb(uint8_t rhport, tusb_control_request_t const * p_request);
 
 //--------------------------------------------------------------------+
 // Inline Functions
diff --git a/src/class/bth/bth_device.c b/src/class/bth/bth_device.c
index cbf6e1332..a79908627 100755
--- a/src/class/bth/bth_device.c
+++ b/src/class/bth/bth_device.c
@@ -42,10 +42,14 @@ typedef struct
   uint8_t itf_num;
   uint8_t ep_ev;
   uint8_t ep_acl_in;
+  uint16_t ep_acl_in_pkt_sz;
   uint8_t ep_acl_out;
   uint8_t ep_voice[2];  // Not used yet
   uint8_t ep_voice_size[2][CFG_TUD_BTH_ISO_ALT_COUNT];
 
+  // Previous amount of bytes sent when issuing ZLP
+  uint32_t prev_xferred_bytes;
+
   // Endpoint Transfer buffer
   CFG_TUSB_MEM_ALIGN bt_hci_cmd_t hci_cmd;
   CFG_TUSB_MEM_ALIGN uint8_t epout_buf[CFG_TUD_BTH_DATA_EPSIZE];
@@ -127,11 +131,25 @@ uint16_t btd_open(uint8_t rhport, tusb_desc_interface_t const *itf_desc, uint16_
   TU_ASSERT(usbd_edpt_open(rhport, desc_ep), 0);
   _btd_itf.ep_ev = desc_ep->bEndpointAddress;
 
+  desc_ep = (tusb_desc_endpoint_t const *)tu_desc_next(desc_ep);
+
   // Open endpoint pair
-  TU_ASSERT(usbd_open_edpt_pair(rhport, tu_desc_next(desc_ep), 2, TUSB_XFER_BULK, &_btd_itf.ep_acl_out,
-                                &_btd_itf.ep_acl_in), 0);
+  TU_ASSERT(usbd_open_edpt_pair(rhport, (uint8_t const *)desc_ep, 2,
+                                TUSB_XFER_BULK, &_btd_itf.ep_acl_out,
+                                &_btd_itf.ep_acl_in),
+            0);
+
+  // Save acl in endpoint max packet size
+  tusb_desc_endpoint_t const *desc_ep_acl_in = desc_ep;
+  for (size_t p = 0; p < 2; p++) {
+    if (tu_edpt_dir(desc_ep_acl_in->bEndpointAddress) == TUSB_DIR_IN) {
+      _btd_itf.ep_acl_in_pkt_sz = tu_edpt_packet_size(desc_ep_acl_in);
+      break;
+    }
+    desc_ep_acl_in = (tusb_desc_endpoint_t const *)tu_desc_next(desc_ep_acl_in);
+  }
 
-  itf_desc = (tusb_desc_interface_t const *)tu_desc_next(tu_desc_next(tu_desc_next(desc_ep)));
+  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_itf.epout_buf, CFG_TUD_BTH_DATA_EPSIZE), 0);
@@ -238,10 +256,8 @@ bool btd_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb_control_request_t c
   return true;
 }
 
-bool btd_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint32_t xferred_bytes)
-{
-  (void)result;
-
+bool btd_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t result,
+                 uint32_t xferred_bytes) {
   // received new data from host
   if (ep_addr == _btd_itf.ep_acl_out)
   {
@@ -256,7 +272,20 @@ bool btd_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint32_t
   }
   else if (ep_addr == _btd_itf.ep_acl_in)
   {
-    if (tud_bt_acl_data_sent_cb) tud_bt_acl_data_sent_cb((uint16_t)xferred_bytes);
+    if ((result == XFER_RESULT_SUCCESS) && (xferred_bytes > 0) &&
+        ((xferred_bytes & (_btd_itf.ep_acl_in_pkt_sz - 1)) == 0)) {
+      // Save number of transferred bytes
+      _btd_itf.prev_xferred_bytes = xferred_bytes;
+
+      // Send zero-length packet
+      tud_bt_acl_data_send(NULL, 0);
+    } else if (tud_bt_acl_data_sent_cb) {
+      if (xferred_bytes == 0) {
+        xferred_bytes = _btd_itf.prev_xferred_bytes;
+        _btd_itf.prev_xferred_bytes = 0;
+      }
+      tud_bt_acl_data_sent_cb((uint16_t)xferred_bytes);
+    }
   }
 
   return true;
diff --git a/src/class/cdc/cdc_device.c b/src/class/cdc/cdc_device.c
index 5057805e2..6d4aae1f2 100644
--- a/src/class/cdc/cdc_device.c
+++ b/src/class/cdc/cdc_device.c
@@ -45,8 +45,7 @@
 //--------------------------------------------------------------------+
 #define BULK_PACKET_SIZE (TUD_OPT_HIGH_SPEED ? 512 : 64)
 
-typedef struct
-{
+typedef struct {
   uint8_t rhport;
   uint8_t itf_num;
   uint8_t ep_notif;
@@ -57,7 +56,7 @@ typedef struct
   uint8_t line_state;
 
   /*------------- From this point, data is not cleared by bus reset -------------*/
-  char    wanted_char;
+  char wanted_char;
   TU_ATTR_ALIGNED(4) cdc_line_coding_t line_coding;
 
   // FIFO
@@ -74,18 +73,21 @@ typedef struct
   CFG_TUSB_MEM_ALIGN cdc_notif_serial_state_t serial_state_buf;
   CFG_TUSB_MEM_ALIGN uint8_t epout_buf[CFG_TUD_CDC_EP_BUFSIZE];
   CFG_TUSB_MEM_ALIGN uint8_t epin_buf[CFG_TUD_CDC_EP_BUFSIZE];
-
-}cdcd_interface_t;
+} cdcd_interface_t;
 
 #define ITF_MEM_RESET_SIZE   offsetof(cdcd_interface_t, wanted_char)
 
 //--------------------------------------------------------------------+
 // INTERNAL OBJECT & FUNCTION DECLARATION
 //--------------------------------------------------------------------+
-CFG_TUD_MEM_SECTION tu_static cdcd_interface_t _cdcd_itf[CFG_TUD_CDC];
+CFG_TUD_MEM_SECTION static cdcd_interface_t _cdcd_itf[CFG_TUD_CDC];
+static tud_cdc_configure_fifo_t _cdcd_fifo_cfg;
+
+static bool _prep_out_transaction (cdcd_interface_t* p_cdc) {
+
+  // Skip if usb is not ready yet
+  TU_VERIFY(tud_ready() && p_cdc->ep_out);
 
-static bool _prep_out_transaction (cdcd_interface_t* p_cdc)
-{
   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.
@@ -100,14 +102,11 @@ static bool _prep_out_transaction (cdcd_interface_t* p_cdc)
   // fifo can be changed before endpoint is claimed
   available = tu_fifo_remaining(&p_cdc->rx_ff);
 
-  if ( available >= sizeof(p_cdc->epout_buf) )
-  {
+  if ( available >= sizeof(p_cdc->epout_buf) ) {
     return usbd_edpt_xfer(p_cdc->rhport, p_cdc->ep_out, p_cdc->epout_buf, sizeof(p_cdc->epout_buf));
-  }else
-  {
+  }else {
     // Release endpoint since we don't make any transfer
     usbd_edpt_release(p_cdc->rhport, p_cdc->ep_out);
-
     return false;
   }
 }
@@ -115,28 +114,35 @@ static bool _prep_out_transaction (cdcd_interface_t* p_cdc)
 //--------------------------------------------------------------------+
 // APPLICATION API
 //--------------------------------------------------------------------+
-bool tud_cdc_n_connected(uint8_t itf)
-{
+
+bool tud_cdc_configure_fifo(tud_cdc_configure_fifo_t const* cfg) {
+  TU_VERIFY(cfg);
+  _cdcd_fifo_cfg = (*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;
+}
+
+bool tud_cdc_n_connected(uint8_t itf) {
   // DTR (bit 0) active  is considered as connected
   return tud_ready() && tu_bit_test(_cdcd_itf[itf].line_state, 0);
 }
 
-uint8_t tud_cdc_n_get_line_state (uint8_t itf)
-{
+uint8_t tud_cdc_n_get_line_state(uint8_t itf) {
   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) {
   (*coding) = _cdcd_itf[itf].line_coding;
 }
 
-bool tud_cdc_n_send_uart_state (uint8_t itf, cdc_uart_state_t state)
-{
+bool tud_cdc_n_send_uart_state (uint8_t itf, cdc_uart_state_t state) {
   cdcd_interface_t* p_cdc = &_cdcd_itf[itf];
 
   // Skip if usb is not ready yet
-  TU_VERIFY( tud_ready(), 0 );
+  TU_VERIFY(tud_ready(), 0);
 
   // claim endpoint
   TU_VERIFY(usbd_edpt_claim(p_cdc->rhport, p_cdc->ep_notif));
@@ -152,34 +158,29 @@ bool tud_cdc_n_send_uart_state (uint8_t itf, cdc_uart_state_t state)
   return usbd_edpt_xfer(p_cdc->rhport, p_cdc->ep_notif, (uint8_t *)&p_cdc->serial_state_buf, sizeof(p_cdc->serial_state_buf));
 }
 
-void tud_cdc_n_set_wanted_char (uint8_t itf, char wanted)
-{
+void tud_cdc_n_set_wanted_char(uint8_t itf, char wanted) {
   _cdcd_itf[itf].wanted_char = wanted;
 }
 
 //--------------------------------------------------------------------+
 // READ API
 //--------------------------------------------------------------------+
-uint32_t tud_cdc_n_available(uint8_t itf)
-{
+uint32_t tud_cdc_n_available(uint8_t itf) {
   return tu_fifo_count(&_cdcd_itf[itf].rx_ff);
 }
 
-uint32_t tud_cdc_n_read(uint8_t itf, void* buffer, uint32_t bufsize)
-{
+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(p_cdc);
   return num_read;
 }
 
-bool tud_cdc_n_peek(uint8_t itf, uint8_t* chr)
-{
+bool tud_cdc_n_peek(uint8_t itf, uint8_t* chr) {
   return tu_fifo_peek(&_cdcd_itf[itf].rx_ff, chr);
 }
 
-void tud_cdc_n_read_flush (uint8_t itf)
-{
+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(p_cdc);
@@ -188,16 +189,15 @@ void tud_cdc_n_read_flush (uint8_t itf)
 //--------------------------------------------------------------------+
 // WRITE API
 //--------------------------------------------------------------------+
-uint32_t tud_cdc_n_write(uint8_t itf, void const* buffer, uint32_t bufsize)
-{
+uint32_t tud_cdc_n_write(uint8_t itf, void const* buffer, uint32_t bufsize) {
   cdcd_interface_t* p_cdc = &_cdcd_itf[itf];
   uint16_t ret = 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
+  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);
   }
@@ -205,28 +205,25 @@ uint32_t tud_cdc_n_write(uint8_t itf, void const* buffer, uint32_t bufsize)
   return ret;
 }
 
-uint32_t tud_cdc_n_write_flush (uint8_t itf)
-{
+uint32_t tud_cdc_n_write_flush(uint8_t itf) {
   cdcd_interface_t* p_cdc = &_cdcd_itf[itf];
 
   // Skip if usb is not ready yet
-  TU_VERIFY( tud_ready(), 0 );
+  TU_VERIFY(tud_ready(), 0);
 
   // No data to send
-  if ( !tu_fifo_count(&p_cdc->tx_ff) ) return 0;
+  if (!tu_fifo_count(&p_cdc->tx_ff)) return 0;
 
   // Claim the endpoint
-  TU_VERIFY( usbd_edpt_claim(p_cdc->rhport, p_cdc->ep_in), 0 );
+  TU_VERIFY(usbd_edpt_claim(p_cdc->rhport, p_cdc->ep_in), 0);
 
   // Pull data from FIFO
   uint16_t const count = tu_fifo_read_n(&p_cdc->tx_ff, p_cdc->epin_buf, sizeof(p_cdc->epin_buf));
 
-  if ( count )
-  {
-    TU_ASSERT( usbd_edpt_xfer(p_cdc->rhport, p_cdc->ep_in, p_cdc->epin_buf, count), 0 );
+  if (count) {
+    TU_ASSERT(usbd_edpt_xfer(p_cdc->rhport, p_cdc->ep_in, p_cdc->epin_buf, count), 0);
     return count;
-  }else
-  {
+  } 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);
@@ -234,33 +231,30 @@ uint32_t tud_cdc_n_write_flush (uint8_t itf)
   }
 }
 
-uint32_t tud_cdc_n_write_available (uint8_t itf)
-{
+uint32_t tud_cdc_n_write_available(uint8_t itf) {
   return tu_fifo_remaining(&_cdcd_itf[itf].tx_ff);
 }
 
-bool tud_cdc_n_write_clear (uint8_t itf)
-{
+bool tud_cdc_n_write_clear(uint8_t itf) {
   return tu_fifo_clear(&_cdcd_itf[itf].tx_ff);
 }
 
 //--------------------------------------------------------------------+
 // USBD Driver API
 //--------------------------------------------------------------------+
-void cdcd_init(void)
-{
+void cdcd_init(void) {
   tu_memclr(_cdcd_itf, sizeof(_cdcd_itf));
+  tu_memclr(&_cdcd_fifo_cfg, sizeof(_cdcd_fifo_cfg));
 
-  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];
 
     p_cdc->wanted_char = (char) -1;
 
     // default line coding is : stop bit = 1, parity = none, data bits = 8
-    p_cdc->line_coding.bit_rate  = 115200;
+    p_cdc->line_coding.bit_rate = 115200;
     p_cdc->line_coding.stop_bits = 0;
-    p_cdc->line_coding.parity    = 0;
+    p_cdc->line_coding.parity = 0;
     p_cdc->line_coding.data_bits = 8;
 
     // Config RX fifo
@@ -304,33 +298,28 @@ bool cdcd_deinit(void) {
   return true;
 }
 
-void cdcd_reset(uint8_t rhport)
-{
+void cdcd_reset(uint8_t rhport) {
   (void) rhport;
 
-  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];
 
     tu_memclr(p_cdc, ITF_MEM_RESET_SIZE);
-    tu_fifo_clear(&p_cdc->rx_ff);
-    tu_fifo_clear(&p_cdc->tx_ff);
+    if (!_cdcd_fifo_cfg.rx_persistent) tu_fifo_clear(&p_cdc->rx_ff);
+    if (!_cdcd_fifo_cfg.tx_persistent) tu_fifo_clear(&p_cdc->tx_ff);
     tu_fifo_set_overwritable(&p_cdc->tx_ff, true);
   }
 }
 
-uint16_t cdcd_open(uint8_t rhport, tusb_desc_interface_t const * itf_desc, uint16_t max_len)
-{
+uint16_t cdcd_open(uint8_t rhport, tusb_desc_interface_t const * 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);
 
   // Find available interface
-  cdcd_interface_t * p_cdc = NULL;
-  for(uint8_t cdc_id=0; cdc_id<CFG_TUD_CDC; cdc_id++)
-  {
-    if ( _cdcd_itf[cdc_id].ep_in == 0 )
-    {
+  cdcd_interface_t* p_cdc = NULL;
+  for (uint8_t cdc_id = 0; cdc_id < CFG_TUD_CDC; cdc_id++) {
+    if (_cdcd_itf[cdc_id].ep_in == 0) {
       p_cdc = &_cdcd_itf[cdc_id];
       break;
     }
@@ -342,39 +331,36 @@ uint16_t cdcd_open(uint8_t rhport, tusb_desc_interface_t const * itf_desc, uint1
   p_cdc->itf_num = itf_desc->bInterfaceNumber;
 
   uint16_t drv_len = sizeof(tusb_desc_interface_t);
-  uint8_t const * p_desc = tu_desc_next( itf_desc );
+  uint8_t const* p_desc = tu_desc_next(itf_desc);
 
   // Communication Functional Descriptors
-  while ( TUSB_DESC_CS_INTERFACE == tu_desc_type(p_desc) && drv_len <= max_len )
-  {
+  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);
+    p_desc = tu_desc_next(p_desc);
   }
 
-  if ( TUSB_DESC_ENDPOINT == tu_desc_type(p_desc) )
-  {
+  if (TUSB_DESC_ENDPOINT == tu_desc_type(p_desc)) {
     // notification endpoint
-    tusb_desc_endpoint_t const * desc_ep = (tusb_desc_endpoint_t const *) p_desc;
+    tusb_desc_endpoint_t const* desc_ep = (tusb_desc_endpoint_t const*) p_desc;
 
-    TU_ASSERT( usbd_edpt_open(rhport, desc_ep), 0 );
+    TU_ASSERT(usbd_edpt_open(rhport, desc_ep), 0);
     p_cdc->ep_notif = desc_ep->bEndpointAddress;
 
     drv_len += tu_desc_len(p_desc);
-    p_desc   = tu_desc_next(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 == ((tusb_desc_interface_t const *) p_desc)->bInterfaceClass) )
-  {
+  if ((TUSB_DESC_INTERFACE == tu_desc_type(p_desc)) &&
+      (TUSB_CLASS_CDC_DATA == ((tusb_desc_interface_t const*) p_desc)->bInterfaceClass)) {
     // next to endpoint descriptor
     drv_len += tu_desc_len(p_desc);
-    p_desc   = tu_desc_next(p_desc);
+    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 );
+    TU_ASSERT(usbd_open_edpt_pair(rhport, p_desc, 2, TUSB_XFER_BULK, &p_cdc->ep_out, &p_cdc->ep_in), 0);
 
-    drv_len += 2*sizeof(tusb_desc_endpoint_t);
+    drv_len += 2 * sizeof(tusb_desc_endpoint_t);
   }
 
   // Prepare for incoming data
@@ -386,8 +372,7 @@ uint16_t cdcd_open(uint8_t rhport, tusb_desc_interface_t const * itf_desc, uint1
 // 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 cdcd_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb_control_request_t const * request)
-{
+bool cdcd_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb_control_request_t const* request) {
   // Handle class request only
   TU_VERIFY(request->bmRequestType_bit.type == TUSB_REQ_TYPE_CLASS);
 
@@ -395,42 +380,33 @@ bool cdcd_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb_control_request_t
   cdcd_interface_t* p_cdc = _cdcd_itf;
 
   // Identify which interface to use
-  for ( ; ; itf++, p_cdc++)
-  {
+  for (;; itf++, p_cdc++) {
     if (itf >= TU_ARRAY_SIZE(_cdcd_itf)) return false;
 
-    if ( p_cdc->itf_num == request->wIndex ) break;
+    if (p_cdc->itf_num == request->wIndex) break;
   }
 
-  switch ( request->bRequest )
-  {
+  switch (request->bRequest) {
     case CDC_REQUEST_SET_LINE_CODING:
-      if (stage == CONTROL_STAGE_SETUP)
-      {
+      if (stage == CONTROL_STAGE_SETUP) {
         TU_LOG_DRV("  Set Line Coding\r\n");
         tud_control_xfer(rhport, request, &p_cdc->line_coding, sizeof(cdc_line_coding_t));
+      } else if (stage == CONTROL_STAGE_ACK) {
+        if (tud_cdc_line_coding_cb) tud_cdc_line_coding_cb(itf, &p_cdc->line_coding);
       }
-      else if ( stage == CONTROL_STAGE_ACK)
-      {
-        if ( tud_cdc_line_coding_cb ) tud_cdc_line_coding_cb(itf, &p_cdc->line_coding);
-      }
-    break;
+      break;
 
     case CDC_REQUEST_GET_LINE_CODING:
-      if (stage == CONTROL_STAGE_SETUP)
-      {
+      if (stage == CONTROL_STAGE_SETUP) {
         TU_LOG_DRV("  Get Line Coding\r\n");
         tud_control_xfer(rhport, request, &p_cdc->line_coding, sizeof(cdc_line_coding_t));
       }
-    break;
+      break;
 
     case CDC_REQUEST_SET_CONTROL_LINE_STATE:
-      if (stage == CONTROL_STAGE_SETUP)
-      {
+      if (stage == CONTROL_STAGE_SETUP) {
         tud_control_status(rhport, request);
-      }
-      else if (stage == CONTROL_STAGE_ACK)
-      {
+      } else if (stage == CONTROL_STAGE_ACK) {
         // CDC PSTN v1.2 section 6.3.12
         // Bit 0: Indicates if DTE is present or not.
         //        This signal corresponds to V.24 signal 108/2 and RS-232 signal DTR (Data Terminal Ready)
@@ -447,61 +423,54 @@ bool cdcd_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb_control_request_t
         TU_LOG_DRV("  Set Control Line State: DTR = %d, RTS = %d\r\n", dtr, rts);
 
         // Invoke callback
-        if ( tud_cdc_line_state_cb ) tud_cdc_line_state_cb(itf, dtr, rts);
+        if (tud_cdc_line_state_cb) tud_cdc_line_state_cb(itf, dtr, rts);
       }
-    break;
+      break;
+
     case CDC_REQUEST_SEND_BREAK:
-      if (stage == CONTROL_STAGE_SETUP)
-      {
+      if (stage == CONTROL_STAGE_SETUP) {
         tud_control_status(rhport, request);
-      }
-      else if (stage == CONTROL_STAGE_ACK)
-      {
+      } else if (stage == CONTROL_STAGE_ACK) {
         TU_LOG_DRV("  Send Break\r\n");
-        if ( tud_cdc_send_break_cb ) tud_cdc_send_break_cb(itf, request->wValue);
+        if (tud_cdc_send_break_cb) tud_cdc_send_break_cb(itf, request->wValue);
       }
-    break;
+      break;
 
-    default: return false; // stall unsupported request
+    default:
+      return false; // stall unsupported request
   }
 
   return true;
 }
 
-bool cdcd_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint32_t xferred_bytes)
-{
+bool cdcd_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint32_t xferred_bytes) {
   (void) result;
 
   uint8_t itf;
   cdcd_interface_t* p_cdc;
 
   // Identify which interface to use
-  for (itf = 0; itf < CFG_TUD_CDC; itf++)
-  {
+  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_notif )) break;
+    if ((ep_addr == p_cdc->ep_out) || (ep_addr == p_cdc->ep_in)|| (ep_addr == p_cdc->ep_notif)) break;
   }
   TU_ASSERT(itf < CFG_TUD_CDC);
 
   // Received new data
-  if ( ep_addr == p_cdc->ep_out )
-  {
+  if (ep_addr == p_cdc->ep_out) {
     tu_fifo_write_n(&p_cdc->rx_ff, p_cdc->epout_buf, (uint16_t) xferred_bytes);
 
     // Check for wanted char and invoke callback if needed
-    if ( tud_cdc_rx_wanted_cb && (((signed char) p_cdc->wanted_char) != -1) )
-    {
-      for ( uint32_t i = 0; i < xferred_bytes; i++ )
-      {
-        if ( (p_cdc->wanted_char == p_cdc->epout_buf[i]) && !tu_fifo_empty(&p_cdc->rx_ff) )
-        {
+    if (tud_cdc_rx_wanted_cb && (((signed char) p_cdc->wanted_char) != -1)) {
+      for (uint32_t i = 0; i < xferred_bytes; i++) {
+        if ((p_cdc->wanted_char == p_cdc->epout_buf[i]) && !tu_fifo_empty(&p_cdc->rx_ff)) {
           tud_cdc_rx_wanted_cb(itf, p_cdc->wanted_char);
         }
       }
     }
 
     // invoke receive callback (if there is still data)
-    if (tud_cdc_rx_cb && !tu_fifo_empty(&p_cdc->rx_ff) ) tud_cdc_rx_cb(itf);
+    if (tud_cdc_rx_cb && !tu_fifo_empty(&p_cdc->rx_ff)) tud_cdc_rx_cb(itf);
 
     // prepare for OUT transaction
     _prep_out_transaction(p_cdc);
@@ -510,19 +479,15 @@ bool cdcd_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint32_
   // 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 == p_cdc->ep_in) {
     // invoke transmit callback to possibly refill tx fifo
-    if ( tud_cdc_tx_complete_cb ) tud_cdc_tx_complete_cb(itf);
+    if (tud_cdc_tx_complete_cb) tud_cdc_tx_complete_cb(itf);
 
-    if ( 0 == tud_cdc_n_write_flush(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) )
-        {
+      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)) {
           usbd_edpt_xfer(rhport, p_cdc->ep_in, NULL, 0);
         }
       }
diff --git a/src/class/cdc/cdc_device.h b/src/class/cdc/cdc_device.h
index 92131f159..be0f31844 100644
--- a/src/class/cdc/cdc_device.h
+++ b/src/class/cdc/cdc_device.h
@@ -24,8 +24,8 @@
  * This file is part of the TinyUSB stack.
  */
 
-#ifndef _TUSB_CDC_DEVICE_H_
-#define _TUSB_CDC_DEVICE_H_
+#ifndef TUSB_CDC_DEVICE_H_
+#define TUSB_CDC_DEVICE_H_
 
 #include "cdc.h"
 
@@ -45,212 +45,174 @@
  extern "C" {
 #endif
 
-/** \addtogroup CDC_Serial Serial
- *  @{
- *  \defgroup   CDC_Serial_Device Device
- *  @{ */
+//--------------------------------------------------------------------+
+// Driver Configuration
+//--------------------------------------------------------------------+
+
+typedef struct TU_ATTR_PACKED {
+  uint8_t rx_persistent : 1; // keep rx fifo on bus reset or disconnect
+  uint8_t tx_persistent : 1; // keep tx fifo on bus reset or disconnect
+} tud_cdc_configure_fifo_t;
+
+// Configure CDC FIFOs behavior
+bool tud_cdc_configure_fifo(tud_cdc_configure_fifo_t const* cfg);
 
 //--------------------------------------------------------------------+
-// Application API (Multiple Ports)
-// CFG_TUD_CDC > 1
+// Application API (Multiple Ports) i.e. CFG_TUD_CDC > 1
 //--------------------------------------------------------------------+
 
+// Check if interface is ready
+bool tud_cdc_n_ready(uint8_t itf);
+
 // Check if terminal is connected to this port
-bool     tud_cdc_n_connected       (uint8_t itf);
+bool tud_cdc_n_connected(uint8_t itf);
 
 // Get current line state. Bit 0:  DTR (Data Terminal Ready), Bit 1: RTS (Request to Send)
-uint8_t  tud_cdc_n_get_line_state  (uint8_t itf);
+uint8_t tud_cdc_n_get_line_state(uint8_t itf);
 
 // Get current line encoding: bit rate, stop bits parity etc ..
-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);
 
 // Send UART status notification: DCD, DSR etc ..
-bool     tud_cdc_n_send_uart_state (uint8_t itf, cdc_uart_state_t state);
+bool tud_cdc_n_send_uart_state(uint8_t itf, cdc_uart_state_t state);
 
 // Set special character that will trigger tud_cdc_rx_wanted_cb() callback on receiving
-void     tud_cdc_n_set_wanted_char (uint8_t itf, char wanted);
+void tud_cdc_n_set_wanted_char(uint8_t itf, char wanted);
 
 // Get the number of bytes available for reading
-uint32_t tud_cdc_n_available       (uint8_t itf);
+uint32_t tud_cdc_n_available(uint8_t itf);
 
 // Read received bytes
-uint32_t tud_cdc_n_read            (uint8_t itf, void* buffer, uint32_t bufsize);
+uint32_t tud_cdc_n_read(uint8_t itf, void* buffer, uint32_t bufsize);
 
 // Read a byte, return -1 if there is none
-static inline
-int32_t  tud_cdc_n_read_char       (uint8_t itf);
+TU_ATTR_ALWAYS_INLINE static inline int32_t tud_cdc_n_read_char(uint8_t itf) {
+  uint8_t ch;
+  return tud_cdc_n_read(itf, &ch, 1) ? (int32_t) ch : -1;
+}
 
 // Clear the received FIFO
-void     tud_cdc_n_read_flush      (uint8_t itf);
+void tud_cdc_n_read_flush(uint8_t itf);
 
 // Get a byte from FIFO without removing it
-bool     tud_cdc_n_peek            (uint8_t itf, uint8_t* ui8);
+bool tud_cdc_n_peek(uint8_t itf, uint8_t* ui8);
 
 // Write bytes to TX FIFO, data may remain in the FIFO for a while
-uint32_t tud_cdc_n_write           (uint8_t itf, void const* buffer, uint32_t bufsize);
+uint32_t tud_cdc_n_write(uint8_t itf, void const* buffer, uint32_t bufsize);
 
 // Write a byte
-static inline
-uint32_t tud_cdc_n_write_char      (uint8_t itf, char ch);
+TU_ATTR_ALWAYS_INLINE static inline uint32_t tud_cdc_n_write_char(uint8_t itf, char ch) {
+  return tud_cdc_n_write(itf, &ch, 1);
+}
 
 // Write a null-terminated string
-static inline
-uint32_t tud_cdc_n_write_str       (uint8_t itf, char const* str);
+TU_ATTR_ALWAYS_INLINE static inline uint32_t tud_cdc_n_write_str(uint8_t itf, char const* str) {
+  return tud_cdc_n_write(itf, str, strlen(str));
+}
 
 // Force sending data if possible, return number of forced bytes
-uint32_t tud_cdc_n_write_flush     (uint8_t itf);
+uint32_t tud_cdc_n_write_flush(uint8_t itf);
 
 // Return the number of bytes (characters) available for writing to TX FIFO buffer in a single n_write operation.
-uint32_t tud_cdc_n_write_available (uint8_t itf);
+uint32_t tud_cdc_n_write_available(uint8_t itf);
 
 // Clear the transmit FIFO
-bool tud_cdc_n_write_clear (uint8_t itf);
+bool tud_cdc_n_write_clear(uint8_t itf);
 
 //--------------------------------------------------------------------+
 // Application API (Single Port)
 //--------------------------------------------------------------------+
-static inline bool     tud_cdc_connected       (void);
-static inline uint8_t  tud_cdc_get_line_state  (void);
-static inline void     tud_cdc_get_line_coding (cdc_line_coding_t* coding);
-static inline bool     tud_cdc_send_uart_state (cdc_uart_state_t state);
-static inline void     tud_cdc_set_wanted_char (char wanted);
-
-static inline uint32_t tud_cdc_available       (void);
-static inline int32_t  tud_cdc_read_char       (void);
-static inline uint32_t tud_cdc_read            (void* buffer, uint32_t bufsize);
-static inline void     tud_cdc_read_flush      (void);
-static inline bool     tud_cdc_peek            (uint8_t* ui8);
-
-static inline uint32_t tud_cdc_write_char      (char ch);
-static inline uint32_t tud_cdc_write           (void const* buffer, uint32_t bufsize);
-static inline uint32_t tud_cdc_write_str       (char const* str);
-static inline uint32_t tud_cdc_write_flush     (void);
-static inline uint32_t tud_cdc_write_available (void);
-static inline bool     tud_cdc_write_clear     (void);
-
-//--------------------------------------------------------------------+
-// Application Callback API (weak is optional)
-//--------------------------------------------------------------------+
-
-// Invoked when received new data
-TU_ATTR_WEAK void tud_cdc_rx_cb(uint8_t itf);
-
-// Invoked when received `wanted_char`
-TU_ATTR_WEAK void tud_cdc_rx_wanted_cb(uint8_t itf, char wanted_char);
-
-// Invoked when a TX is complete and therefore space becomes available in TX buffer
-TU_ATTR_WEAK void tud_cdc_tx_complete_cb(uint8_t itf);
-
-// Invoked when line state DTR & RTS are changed via SET_CONTROL_LINE_STATE
-TU_ATTR_WEAK void tud_cdc_line_state_cb(uint8_t itf, bool dtr, bool rts);
-
-// Invoked when line coding is change via SET_LINE_CODING
-TU_ATTR_WEAK void tud_cdc_line_coding_cb(uint8_t itf, cdc_line_coding_t const* p_line_coding);
-
-// Invoked when received send break
-TU_ATTR_WEAK void tud_cdc_send_break_cb(uint8_t itf, uint16_t duration_ms);
-
-//--------------------------------------------------------------------+
-// Inline Functions
-//--------------------------------------------------------------------+
-static inline int32_t tud_cdc_n_read_char (uint8_t itf)
-{
-  uint8_t ch;
-  return tud_cdc_n_read(itf, &ch, 1) ? (int32_t) ch : -1;
-}
 
-static inline uint32_t tud_cdc_n_write_char(uint8_t itf, char ch)
-{
-  return tud_cdc_n_write(itf, &ch, 1);
+TU_ATTR_ALWAYS_INLINE static inline bool tud_cdc_ready(void) {
+  return tud_cdc_n_ready(0);
 }
 
-static inline uint32_t tud_cdc_n_write_str (uint8_t itf, char const* str)
-{
-  return tud_cdc_n_write(itf, str, strlen(str));
-}
-
-static inline bool tud_cdc_connected (void)
-{
+TU_ATTR_ALWAYS_INLINE static inline bool tud_cdc_connected(void) {
   return tud_cdc_n_connected(0);
 }
 
-static inline uint8_t tud_cdc_get_line_state (void)
-{
+TU_ATTR_ALWAYS_INLINE static inline uint8_t tud_cdc_get_line_state(void) {
   return tud_cdc_n_get_line_state(0);
 }
 
-static inline void tud_cdc_get_line_coding (cdc_line_coding_t* coding)
-{
+TU_ATTR_ALWAYS_INLINE static inline void tud_cdc_get_line_coding(cdc_line_coding_t* coding) {
   tud_cdc_n_get_line_coding(0, coding);
 }
 
-static inline bool tud_cdc_send_uart_state (cdc_uart_state_t state)
-{
+TU_ATTR_ALWAYS_INLINE static inline bool tud_cdc_send_uart_state(cdc_uart_state_t state) {
   return tud_cdc_n_send_uart_state(0, state);
 }
 
-static inline void tud_cdc_set_wanted_char (char wanted)
-{
+
+TU_ATTR_ALWAYS_INLINE static inline void tud_cdc_set_wanted_char(char wanted) {
   tud_cdc_n_set_wanted_char(0, wanted);
 }
 
-static inline uint32_t tud_cdc_available (void)
-{
+TU_ATTR_ALWAYS_INLINE static inline uint32_t tud_cdc_available(void) {
   return tud_cdc_n_available(0);
 }
 
-static inline int32_t tud_cdc_read_char (void)
-{
+TU_ATTR_ALWAYS_INLINE static inline int32_t tud_cdc_read_char(void) {
   return tud_cdc_n_read_char(0);
 }
 
-static inline uint32_t tud_cdc_read (void* buffer, uint32_t bufsize)
-{
+TU_ATTR_ALWAYS_INLINE static inline uint32_t tud_cdc_read(void* buffer, uint32_t bufsize) {
   return tud_cdc_n_read(0, buffer, bufsize);
 }
 
-static inline void tud_cdc_read_flush (void)
-{
+TU_ATTR_ALWAYS_INLINE static inline void tud_cdc_read_flush(void) {
   tud_cdc_n_read_flush(0);
 }
 
-static inline bool tud_cdc_peek (uint8_t* ui8)
-{
+TU_ATTR_ALWAYS_INLINE static inline bool tud_cdc_peek(uint8_t* ui8) {
   return tud_cdc_n_peek(0, ui8);
 }
 
-static inline uint32_t tud_cdc_write_char (char ch)
-{
+TU_ATTR_ALWAYS_INLINE static inline uint32_t tud_cdc_write_char(char ch) {
   return tud_cdc_n_write_char(0, ch);
 }
 
-static inline uint32_t tud_cdc_write (void const* buffer, uint32_t bufsize)
-{
+TU_ATTR_ALWAYS_INLINE static inline uint32_t tud_cdc_write(void const* buffer, uint32_t bufsize) {
   return tud_cdc_n_write(0, buffer, bufsize);
 }
 
-static inline uint32_t tud_cdc_write_str (char const* str)
-{
+TU_ATTR_ALWAYS_INLINE static inline uint32_t tud_cdc_write_str(char const* str) {
   return tud_cdc_n_write_str(0, str);
 }
 
-static inline uint32_t tud_cdc_write_flush (void)
-{
+TU_ATTR_ALWAYS_INLINE static inline uint32_t tud_cdc_write_flush(void) {
   return tud_cdc_n_write_flush(0);
 }
 
-static inline uint32_t tud_cdc_write_available(void)
-{
+TU_ATTR_ALWAYS_INLINE static inline uint32_t tud_cdc_write_available(void) {
   return tud_cdc_n_write_available(0);
 }
 
-static inline bool tud_cdc_write_clear(void)
-{
+TU_ATTR_ALWAYS_INLINE static inline bool tud_cdc_write_clear(void) {
   return tud_cdc_n_write_clear(0);
 }
 
-/** @} */
-/** @} */
+//--------------------------------------------------------------------+
+// Application Callback API (weak is optional)
+//--------------------------------------------------------------------+
+
+// Invoked when received new data
+TU_ATTR_WEAK void tud_cdc_rx_cb(uint8_t itf);
+
+// Invoked when received `wanted_char`
+TU_ATTR_WEAK void tud_cdc_rx_wanted_cb(uint8_t itf, char wanted_char);
+
+// Invoked when a TX is complete and therefore space becomes available in TX buffer
+TU_ATTR_WEAK void tud_cdc_tx_complete_cb(uint8_t itf);
+
+// Invoked when line state DTR & RTS are changed via SET_CONTROL_LINE_STATE
+TU_ATTR_WEAK void tud_cdc_line_state_cb(uint8_t itf, bool dtr, bool rts);
+
+// Invoked when line coding is change via SET_LINE_CODING
+TU_ATTR_WEAK void tud_cdc_line_coding_cb(uint8_t itf, cdc_line_coding_t const* p_line_coding);
+
+// Invoked when received send break
+TU_ATTR_WEAK void tud_cdc_send_break_cb(uint8_t itf, uint16_t duration_ms);
 
 //--------------------------------------------------------------------+
 // INTERNAL USBD-CLASS DRIVER API
diff --git a/src/class/cdc/cdc_host.c b/src/class/cdc/cdc_host.c
index 133a10f6e..8717970e6 100644
--- a/src/class/cdc/cdc_host.c
+++ b/src/class/cdc/cdc_host.c
@@ -341,14 +341,14 @@ uint32_t tuh_cdc_write(uint8_t idx, void const* buffer, uint32_t bufsize) {
   cdch_interface_t* p_cdc = get_itf(idx);
   TU_VERIFY(p_cdc);
 
-  return tu_edpt_stream_write(&p_cdc->stream.tx, buffer, bufsize);
+  return tu_edpt_stream_write(p_cdc->daddr, &p_cdc->stream.tx, buffer, bufsize);
 }
 
 uint32_t tuh_cdc_write_flush(uint8_t idx) {
   cdch_interface_t* p_cdc = get_itf(idx);
   TU_VERIFY(p_cdc);
 
-  return tu_edpt_stream_write_xfer(&p_cdc->stream.tx);
+  return tu_edpt_stream_write_xfer(p_cdc->daddr, &p_cdc->stream.tx);
 }
 
 bool tuh_cdc_write_clear(uint8_t idx) {
@@ -362,7 +362,7 @@ uint32_t tuh_cdc_write_available(uint8_t idx) {
   cdch_interface_t* p_cdc = get_itf(idx);
   TU_VERIFY(p_cdc);
 
-  return tu_edpt_stream_write_available(&p_cdc->stream.tx);
+  return tu_edpt_stream_write_available(p_cdc->daddr, &p_cdc->stream.tx);
 }
 
 //--------------------------------------------------------------------+
@@ -373,7 +373,7 @@ uint32_t tuh_cdc_read (uint8_t idx, void* buffer, uint32_t bufsize) {
   cdch_interface_t* p_cdc = get_itf(idx);
   TU_VERIFY(p_cdc);
 
-  return tu_edpt_stream_read(&p_cdc->stream.rx, buffer, bufsize);
+  return tu_edpt_stream_read(p_cdc->daddr, &p_cdc->stream.rx, buffer, bufsize);
 }
 
 uint32_t tuh_cdc_read_available(uint8_t idx) {
@@ -395,7 +395,7 @@ 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->stream.rx);
+  tu_edpt_stream_read_xfer(p_cdc->daddr, &p_cdc->stream.rx);
   return ret;
 }
 
@@ -677,10 +677,10 @@ bool cdch_xfer_cb(uint8_t daddr, uint8_t ep_addr, xfer_result_t event, uint32_t
     // invoke tx complete callback to possibly refill tx fifo
     if (tuh_cdc_tx_complete_cb) tuh_cdc_tx_complete_cb(idx);
 
-    if ( 0 == tu_edpt_stream_write_xfer(&p_cdc->stream.tx) ) {
+    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(&p_cdc->stream.tx, xferred_bytes);
+      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
@@ -698,7 +698,7 @@ bool cdch_xfer_cb(uint8_t daddr, uint8_t ep_addr, xfer_result_t event, uint32_t
     if (tuh_cdc_rx_cb) tuh_cdc_rx_cb(idx);
 
     // prepare for next transfer if needed
-    tu_edpt_stream_read_xfer(&p_cdc->stream.rx);
+    tu_edpt_stream_read_xfer(daddr, &p_cdc->stream.rx);
   }else if ( ep_addr == p_cdc->ep_notif ) {
     // TODO handle notification endpoint
   }else {
@@ -719,9 +719,9 @@ static bool open_ep_stream_pair(cdch_interface_t* p_cdc, tusb_desc_endpoint_t co
     TU_ASSERT(tuh_edpt_open(p_cdc->daddr, desc_ep));
 
     if (tu_edpt_dir(desc_ep->bEndpointAddress) == TUSB_DIR_IN) {
-      tu_edpt_stream_open(&p_cdc->stream.rx, p_cdc->daddr, desc_ep);
+      tu_edpt_stream_open(&p_cdc->stream.rx, desc_ep);
     } else {
-      tu_edpt_stream_open(&p_cdc->stream.tx, p_cdc->daddr, desc_ep);
+      tu_edpt_stream_open(&p_cdc->stream.tx, desc_ep);
     }
 
     desc_ep = (tusb_desc_endpoint_t const*) tu_desc_next(desc_ep);
@@ -763,7 +763,7 @@ static void set_config_complete(cdch_interface_t * p_cdc, uint8_t idx, uint8_t i
   if (tuh_cdc_mount_cb) tuh_cdc_mount_cb(idx);
 
   // Prepare for incoming data
-  tu_edpt_stream_read_xfer(&p_cdc->stream.rx);
+  tu_edpt_stream_read_xfer(p_cdc->daddr, &p_cdc->stream.rx);
 
   // notify usbh that driver enumeration is complete
   usbh_driver_set_config_complete(p_cdc->daddr, itf_num);
diff --git a/src/class/hid/hid.h b/src/class/hid/hid.h
index fcaab7a50..c2b5a8a48 100644
--- a/src/class/hid/hid.h
+++ b/src/class/hid/hid.h
@@ -366,177 +366,224 @@ typedef enum
 //--------------------------------------------------------------------+
 // HID KEYCODE
 //--------------------------------------------------------------------+
-#define HID_KEY_NONE                      0x00
-#define HID_KEY_A                         0x04
-#define HID_KEY_B                         0x05
-#define HID_KEY_C                         0x06
-#define HID_KEY_D                         0x07
-#define HID_KEY_E                         0x08
-#define HID_KEY_F                         0x09
-#define HID_KEY_G                         0x0A
-#define HID_KEY_H                         0x0B
-#define HID_KEY_I                         0x0C
-#define HID_KEY_J                         0x0D
-#define HID_KEY_K                         0x0E
-#define HID_KEY_L                         0x0F
-#define HID_KEY_M                         0x10
-#define HID_KEY_N                         0x11
-#define HID_KEY_O                         0x12
-#define HID_KEY_P                         0x13
-#define HID_KEY_Q                         0x14
-#define HID_KEY_R                         0x15
-#define HID_KEY_S                         0x16
-#define HID_KEY_T                         0x17
-#define HID_KEY_U                         0x18
-#define HID_KEY_V                         0x19
-#define HID_KEY_W                         0x1A
-#define HID_KEY_X                         0x1B
-#define HID_KEY_Y                         0x1C
-#define HID_KEY_Z                         0x1D
-#define HID_KEY_1                         0x1E
-#define HID_KEY_2                         0x1F
-#define HID_KEY_3                         0x20
-#define HID_KEY_4                         0x21
-#define HID_KEY_5                         0x22
-#define HID_KEY_6                         0x23
-#define HID_KEY_7                         0x24
-#define HID_KEY_8                         0x25
-#define HID_KEY_9                         0x26
-#define HID_KEY_0                         0x27
-#define HID_KEY_ENTER                     0x28
-#define HID_KEY_ESCAPE                    0x29
-#define HID_KEY_BACKSPACE                 0x2A
-#define HID_KEY_TAB                       0x2B
-#define HID_KEY_SPACE                     0x2C
-#define HID_KEY_MINUS                     0x2D
-#define HID_KEY_EQUAL                     0x2E
-#define HID_KEY_BRACKET_LEFT              0x2F
-#define HID_KEY_BRACKET_RIGHT             0x30
-#define HID_KEY_BACKSLASH                 0x31
-#define HID_KEY_EUROPE_1                  0x32
-#define HID_KEY_SEMICOLON                 0x33
-#define HID_KEY_APOSTROPHE                0x34
-#define HID_KEY_GRAVE                     0x35
-#define HID_KEY_COMMA                     0x36
-#define HID_KEY_PERIOD                    0x37
-#define HID_KEY_SLASH                     0x38
-#define HID_KEY_CAPS_LOCK                 0x39
-#define HID_KEY_F1                        0x3A
-#define HID_KEY_F2                        0x3B
-#define HID_KEY_F3                        0x3C
-#define HID_KEY_F4                        0x3D
-#define HID_KEY_F5                        0x3E
-#define HID_KEY_F6                        0x3F
-#define HID_KEY_F7                        0x40
-#define HID_KEY_F8                        0x41
-#define HID_KEY_F9                        0x42
-#define HID_KEY_F10                       0x43
-#define HID_KEY_F11                       0x44
-#define HID_KEY_F12                       0x45
-#define HID_KEY_PRINT_SCREEN              0x46
-#define HID_KEY_SCROLL_LOCK               0x47
-#define HID_KEY_PAUSE                     0x48
-#define HID_KEY_INSERT                    0x49
-#define HID_KEY_HOME                      0x4A
-#define HID_KEY_PAGE_UP                   0x4B
-#define HID_KEY_DELETE                    0x4C
-#define HID_KEY_END                       0x4D
-#define HID_KEY_PAGE_DOWN                 0x4E
-#define HID_KEY_ARROW_RIGHT               0x4F
-#define HID_KEY_ARROW_LEFT                0x50
-#define HID_KEY_ARROW_DOWN                0x51
-#define HID_KEY_ARROW_UP                  0x52
-#define HID_KEY_NUM_LOCK                  0x53
-#define HID_KEY_KEYPAD_DIVIDE             0x54
-#define HID_KEY_KEYPAD_MULTIPLY           0x55
-#define HID_KEY_KEYPAD_SUBTRACT           0x56
-#define HID_KEY_KEYPAD_ADD                0x57
-#define HID_KEY_KEYPAD_ENTER              0x58
-#define HID_KEY_KEYPAD_1                  0x59
-#define HID_KEY_KEYPAD_2                  0x5A
-#define HID_KEY_KEYPAD_3                  0x5B
-#define HID_KEY_KEYPAD_4                  0x5C
-#define HID_KEY_KEYPAD_5                  0x5D
-#define HID_KEY_KEYPAD_6                  0x5E
-#define HID_KEY_KEYPAD_7                  0x5F
-#define HID_KEY_KEYPAD_8                  0x60
-#define HID_KEY_KEYPAD_9                  0x61
-#define HID_KEY_KEYPAD_0                  0x62
-#define HID_KEY_KEYPAD_DECIMAL            0x63
-#define HID_KEY_EUROPE_2                  0x64
-#define HID_KEY_APPLICATION               0x65
-#define HID_KEY_POWER                     0x66
-#define HID_KEY_KEYPAD_EQUAL              0x67
-#define HID_KEY_F13                       0x68
-#define HID_KEY_F14                       0x69
-#define HID_KEY_F15                       0x6A
-#define HID_KEY_F16                       0x6B
-#define HID_KEY_F17                       0x6C
-#define HID_KEY_F18                       0x6D
-#define HID_KEY_F19                       0x6E
-#define HID_KEY_F20                       0x6F
-#define HID_KEY_F21                       0x70
-#define HID_KEY_F22                       0x71
-#define HID_KEY_F23                       0x72
-#define HID_KEY_F24                       0x73
-#define HID_KEY_EXECUTE                   0x74
-#define HID_KEY_HELP                      0x75
-#define HID_KEY_MENU                      0x76
-#define HID_KEY_SELECT                    0x77
-#define HID_KEY_STOP                      0x78
-#define HID_KEY_AGAIN                     0x79
-#define HID_KEY_UNDO                      0x7A
-#define HID_KEY_CUT                       0x7B
-#define HID_KEY_COPY                      0x7C
-#define HID_KEY_PASTE                     0x7D
-#define HID_KEY_FIND                      0x7E
-#define HID_KEY_MUTE                      0x7F
-#define HID_KEY_VOLUME_UP                 0x80
-#define HID_KEY_VOLUME_DOWN               0x81
-#define HID_KEY_LOCKING_CAPS_LOCK         0x82
-#define HID_KEY_LOCKING_NUM_LOCK          0x83
-#define HID_KEY_LOCKING_SCROLL_LOCK       0x84
-#define HID_KEY_KEYPAD_COMMA              0x85
-#define HID_KEY_KEYPAD_EQUAL_SIGN         0x86
-#define HID_KEY_KANJI1                    0x87
-#define HID_KEY_KANJI2                    0x88
-#define HID_KEY_KANJI3                    0x89
-#define HID_KEY_KANJI4                    0x8A
-#define HID_KEY_KANJI5                    0x8B
-#define HID_KEY_KANJI6                    0x8C
-#define HID_KEY_KANJI7                    0x8D
-#define HID_KEY_KANJI8                    0x8E
-#define HID_KEY_KANJI9                    0x8F
-#define HID_KEY_LANG1                     0x90
-#define HID_KEY_LANG2                     0x91
-#define HID_KEY_LANG3                     0x92
-#define HID_KEY_LANG4                     0x93
-#define HID_KEY_LANG5                     0x94
-#define HID_KEY_LANG6                     0x95
-#define HID_KEY_LANG7                     0x96
-#define HID_KEY_LANG8                     0x97
-#define HID_KEY_LANG9                     0x98
-#define HID_KEY_ALTERNATE_ERASE           0x99
-#define HID_KEY_SYSREQ_ATTENTION          0x9A
-#define HID_KEY_CANCEL                    0x9B
-#define HID_KEY_CLEAR                     0x9C
-#define HID_KEY_PRIOR                     0x9D
-#define HID_KEY_RETURN                    0x9E
-#define HID_KEY_SEPARATOR                 0x9F
-#define HID_KEY_OUT                       0xA0
-#define HID_KEY_OPER                      0xA1
-#define HID_KEY_CLEAR_AGAIN               0xA2
-#define HID_KEY_CRSEL_PROPS               0xA3
-#define HID_KEY_EXSEL                     0xA4
-// RESERVED					                      0xA5-DF
-#define HID_KEY_CONTROL_LEFT              0xE0
-#define HID_KEY_SHIFT_LEFT                0xE1
-#define HID_KEY_ALT_LEFT                  0xE2
-#define HID_KEY_GUI_LEFT                  0xE3
-#define HID_KEY_CONTROL_RIGHT             0xE4
-#define HID_KEY_SHIFT_RIGHT               0xE5
-#define HID_KEY_ALT_RIGHT                 0xE6
-#define HID_KEY_GUI_RIGHT                 0xE7
+#define HID_KEY_NONE                        0x00
+#define HID_KEY_A                           0x04
+#define HID_KEY_B                           0x05
+#define HID_KEY_C                           0x06
+#define HID_KEY_D                           0x07
+#define HID_KEY_E                           0x08
+#define HID_KEY_F                           0x09
+#define HID_KEY_G                           0x0A
+#define HID_KEY_H                           0x0B
+#define HID_KEY_I                           0x0C
+#define HID_KEY_J                           0x0D
+#define HID_KEY_K                           0x0E
+#define HID_KEY_L                           0x0F
+#define HID_KEY_M                           0x10
+#define HID_KEY_N                           0x11
+#define HID_KEY_O                           0x12
+#define HID_KEY_P                           0x13
+#define HID_KEY_Q                           0x14
+#define HID_KEY_R                           0x15
+#define HID_KEY_S                           0x16
+#define HID_KEY_T                           0x17
+#define HID_KEY_U                           0x18
+#define HID_KEY_V                           0x19
+#define HID_KEY_W                           0x1A
+#define HID_KEY_X                           0x1B
+#define HID_KEY_Y                           0x1C
+#define HID_KEY_Z                           0x1D
+#define HID_KEY_1                           0x1E
+#define HID_KEY_2                           0x1F
+#define HID_KEY_3                           0x20
+#define HID_KEY_4                           0x21
+#define HID_KEY_5                           0x22
+#define HID_KEY_6                           0x23
+#define HID_KEY_7                           0x24
+#define HID_KEY_8                           0x25
+#define HID_KEY_9                           0x26
+#define HID_KEY_0                           0x27
+#define HID_KEY_ENTER                       0x28
+#define HID_KEY_ESCAPE                      0x29
+#define HID_KEY_BACKSPACE                   0x2A
+#define HID_KEY_TAB                         0x2B
+#define HID_KEY_SPACE                       0x2C
+#define HID_KEY_MINUS                       0x2D
+#define HID_KEY_EQUAL                       0x2E
+#define HID_KEY_BRACKET_LEFT                0x2F
+#define HID_KEY_BRACKET_RIGHT               0x30
+#define HID_KEY_BACKSLASH                   0x31
+#define HID_KEY_EUROPE_1                    0x32
+#define HID_KEY_SEMICOLON                   0x33
+#define HID_KEY_APOSTROPHE                  0x34
+#define HID_KEY_GRAVE                       0x35
+#define HID_KEY_COMMA                       0x36
+#define HID_KEY_PERIOD                      0x37
+#define HID_KEY_SLASH                       0x38
+#define HID_KEY_CAPS_LOCK                   0x39
+#define HID_KEY_F1                          0x3A
+#define HID_KEY_F2                          0x3B
+#define HID_KEY_F3                          0x3C
+#define HID_KEY_F4                          0x3D
+#define HID_KEY_F5                          0x3E
+#define HID_KEY_F6                          0x3F
+#define HID_KEY_F7                          0x40
+#define HID_KEY_F8                          0x41
+#define HID_KEY_F9                          0x42
+#define HID_KEY_F10                         0x43
+#define HID_KEY_F11                         0x44
+#define HID_KEY_F12                         0x45
+#define HID_KEY_PRINT_SCREEN                0x46
+#define HID_KEY_SCROLL_LOCK                 0x47
+#define HID_KEY_PAUSE                       0x48
+#define HID_KEY_INSERT                      0x49
+#define HID_KEY_HOME                        0x4A
+#define HID_KEY_PAGE_UP                     0x4B
+#define HID_KEY_DELETE                      0x4C
+#define HID_KEY_END                         0x4D
+#define HID_KEY_PAGE_DOWN                   0x4E
+#define HID_KEY_ARROW_RIGHT                 0x4F
+#define HID_KEY_ARROW_LEFT                  0x50
+#define HID_KEY_ARROW_DOWN                  0x51
+#define HID_KEY_ARROW_UP                    0x52
+#define HID_KEY_NUM_LOCK                    0x53
+#define HID_KEY_KEYPAD_DIVIDE               0x54
+#define HID_KEY_KEYPAD_MULTIPLY             0x55
+#define HID_KEY_KEYPAD_SUBTRACT             0x56
+#define HID_KEY_KEYPAD_ADD                  0x57
+#define HID_KEY_KEYPAD_ENTER                0x58
+#define HID_KEY_KEYPAD_1                    0x59
+#define HID_KEY_KEYPAD_2                    0x5A
+#define HID_KEY_KEYPAD_3                    0x5B
+#define HID_KEY_KEYPAD_4                    0x5C
+#define HID_KEY_KEYPAD_5                    0x5D
+#define HID_KEY_KEYPAD_6                    0x5E
+#define HID_KEY_KEYPAD_7                    0x5F
+#define HID_KEY_KEYPAD_8                    0x60
+#define HID_KEY_KEYPAD_9                    0x61
+#define HID_KEY_KEYPAD_0                    0x62
+#define HID_KEY_KEYPAD_DECIMAL              0x63
+#define HID_KEY_EUROPE_2                    0x64
+#define HID_KEY_APPLICATION                 0x65
+#define HID_KEY_POWER                       0x66
+#define HID_KEY_KEYPAD_EQUAL                0x67
+#define HID_KEY_F13                         0x68
+#define HID_KEY_F14                         0x69
+#define HID_KEY_F15                         0x6A
+#define HID_KEY_F16                         0x6B
+#define HID_KEY_F17                         0x6C
+#define HID_KEY_F18                         0x6D
+#define HID_KEY_F19                         0x6E
+#define HID_KEY_F20                         0x6F
+#define HID_KEY_F21                         0x70
+#define HID_KEY_F22                         0x71
+#define HID_KEY_F23                         0x72
+#define HID_KEY_F24                         0x73
+#define HID_KEY_EXECUTE                     0x74
+#define HID_KEY_HELP                        0x75
+#define HID_KEY_MENU                        0x76
+#define HID_KEY_SELECT                      0x77
+#define HID_KEY_STOP                        0x78
+#define HID_KEY_AGAIN                       0x79
+#define HID_KEY_UNDO                        0x7A
+#define HID_KEY_CUT                         0x7B
+#define HID_KEY_COPY                        0x7C
+#define HID_KEY_PASTE                       0x7D
+#define HID_KEY_FIND                        0x7E
+#define HID_KEY_MUTE                        0x7F
+#define HID_KEY_VOLUME_UP                   0x80
+#define HID_KEY_VOLUME_DOWN                 0x81
+#define HID_KEY_LOCKING_CAPS_LOCK           0x82
+#define HID_KEY_LOCKING_NUM_LOCK            0x83
+#define HID_KEY_LOCKING_SCROLL_LOCK         0x84
+#define HID_KEY_KEYPAD_COMMA                0x85
+#define HID_KEY_KEYPAD_EQUAL_SIGN           0x86
+#define HID_KEY_KANJI1                      0x87
+#define HID_KEY_KANJI2                      0x88
+#define HID_KEY_KANJI3                      0x89
+#define HID_KEY_KANJI4                      0x8A
+#define HID_KEY_KANJI5                      0x8B
+#define HID_KEY_KANJI6                      0x8C
+#define HID_KEY_KANJI7                      0x8D
+#define HID_KEY_KANJI8                      0x8E
+#define HID_KEY_KANJI9                      0x8F
+#define HID_KEY_LANG1                       0x90
+#define HID_KEY_LANG2                       0x91
+#define HID_KEY_LANG3                       0x92
+#define HID_KEY_LANG4                       0x93
+#define HID_KEY_LANG5                       0x94
+#define HID_KEY_LANG6                       0x95
+#define HID_KEY_LANG7                       0x96
+#define HID_KEY_LANG8                       0x97
+#define HID_KEY_LANG9                       0x98
+#define HID_KEY_ALTERNATE_ERASE             0x99
+#define HID_KEY_SYSREQ_ATTENTION            0x9A
+#define HID_KEY_CANCEL                      0x9B
+#define HID_KEY_CLEAR                       0x9C
+#define HID_KEY_PRIOR                       0x9D
+#define HID_KEY_RETURN                      0x9E
+#define HID_KEY_SEPARATOR                   0x9F
+#define HID_KEY_OUT                         0xA0
+#define HID_KEY_OPER                        0xA1
+#define HID_KEY_CLEAR_AGAIN                 0xA2
+#define HID_KEY_CRSEL_PROPS                 0xA3
+#define HID_KEY_EXSEL                       0xA4
+// RESERVED					                        0xA5-AF
+#define HID_KEY_KEYPAD_00                   0xB0
+#define HID_KEY_KEYPAD_000                  0xB1
+#define HID_KEY_THOUSANDS_SEPARATOR         0xB2
+#define HID_KEY_DECIMAL_SEPARATOR           0xB3
+#define HID_KEY_CURRENCY_UNIT               0xB4
+#define HID_KEY_CURRENCY_SUBUNIT            0xB5
+#define HID_KEY_KEYPAD_LEFT_PARENTHESIS     0xB6
+#define HID_KEY_KEYPAD_RIGHT_PARENTHESIS    0xB7
+#define HID_KEY_KEYPAD_LEFT_BRACE           0xB8
+#define HID_KEY_KEYPAD_RIGHT_BRACE          0xB9
+#define HID_KEY_KEYPAD_TAB                  0xBA
+#define HID_KEY_KEYPAD_BACKSPACE            0xBB
+#define HID_KEY_KEYPAD_A                    0xBC
+#define HID_KEY_KEYPAD_B                    0xBD
+#define HID_KEY_KEYPAD_C                    0xBE
+#define HID_KEY_KEYPAD_D                    0xBF
+#define HID_KEY_KEYPAD_E                    0xC0
+#define HID_KEY_KEYPAD_F                    0xC1
+#define HID_KEY_KEYPAD_XOR                  0xC2
+#define HID_KEY_KEYPAD_CARET                0xC3
+#define HID_KEY_KEYPAD_PERCENT              0xC4
+#define HID_KEY_KEYPAD_LESS_THAN            0xC5
+#define HID_KEY_KEYPAD_GREATER_THAN         0xC6
+#define HID_KEY_KEYPAD_AMPERSAND            0xC7
+#define HID_KEY_KEYPAD_DOUBLE_AMPERSAND     0xC8
+#define HID_KEY_KEYPAD_VERTICAL_BAR         0xC9
+#define HID_KEY_KEYPAD_DOUBLE_VERTICAL_BAR  0xCA
+#define HID_KEY_KEYPAD_COLON                0xCB
+#define HID_KEY_KEYPAD_HASH                 0xCC
+#define HID_KEY_KEYPAD_SPACE                0xCD
+#define HID_KEY_KEYPAD_AT                   0xCE
+#define HID_KEY_KEYPAD_EXCLAMATION          0xCF
+#define HID_KEY_KEYPAD_MEMORY_STORE         0xD0
+#define HID_KEY_KEYPAD_MEMORY_RECALL        0xD1
+#define HID_KEY_KEYPAD_MEMORY_CLEAR         0xD2
+#define HID_KEY_KEYPAD_MEMORY_ADD           0xD3
+#define HID_KEY_KEYPAD_MEMORY_SUBTRACT      0xD4
+#define HID_KEY_KEYPAD_MEMORY_MULTIPLY      0xD5
+#define HID_KEY_KEYPAD_MEMORY_DIVIDE        0xD6
+#define HID_KEY_KEYPAD_PLUS_MINUS           0xD7
+#define HID_KEY_KEYPAD_CLEAR                0xD8
+#define HID_KEY_KEYPAD_CLEAR_ENTRY          0xD9
+#define HID_KEY_KEYPAD_BINARY               0xDA
+#define HID_KEY_KEYPAD_OCTAL                0xDB
+#define HID_KEY_KEYPAD_DECIMAL_2            0xDC
+#define HID_KEY_KEYPAD_HEXADECIMAL          0xDD
+// RESERVED					                        0xDE-DF
+#define HID_KEY_CONTROL_LEFT                0xE0
+#define HID_KEY_SHIFT_LEFT                  0xE1
+#define HID_KEY_ALT_LEFT                    0xE2
+#define HID_KEY_GUI_LEFT                    0xE3
+#define HID_KEY_CONTROL_RIGHT               0xE4
+#define HID_KEY_SHIFT_RIGHT                 0xE5
+#define HID_KEY_ALT_RIGHT                   0xE6
+#define HID_KEY_GUI_RIGHT                   0xE7
 
 
 //--------------------------------------------------------------------+
@@ -697,32 +744,33 @@ enum {
 
 /// HID Usage Table - Table 1: Usage Page Summary
 enum {
-  HID_USAGE_PAGE_DESKTOP         = 0x01,
-  HID_USAGE_PAGE_SIMULATE        = 0x02,
-  HID_USAGE_PAGE_VIRTUAL_REALITY = 0x03,
-  HID_USAGE_PAGE_SPORT           = 0x04,
-  HID_USAGE_PAGE_GAME            = 0x05,
-  HID_USAGE_PAGE_GENERIC_DEVICE  = 0x06,
-  HID_USAGE_PAGE_KEYBOARD        = 0x07,
-  HID_USAGE_PAGE_LED             = 0x08,
-  HID_USAGE_PAGE_BUTTON          = 0x09,
-  HID_USAGE_PAGE_ORDINAL         = 0x0a,
-  HID_USAGE_PAGE_TELEPHONY       = 0x0b,
-  HID_USAGE_PAGE_CONSUMER        = 0x0c,
-  HID_USAGE_PAGE_DIGITIZER       = 0x0d,
-  HID_USAGE_PAGE_PID             = 0x0f,
-  HID_USAGE_PAGE_UNICODE         = 0x10,
-  HID_USAGE_PAGE_ALPHA_DISPLAY   = 0x14,
-  HID_USAGE_PAGE_MEDICAL         = 0x40,
-  HID_USAGE_PAGE_MONITOR         = 0x80, //0x80 - 0x83
-  HID_USAGE_PAGE_POWER           = 0x84, // 0x084 - 0x87
-  HID_USAGE_PAGE_BARCODE_SCANNER = 0x8c,
-  HID_USAGE_PAGE_SCALE           = 0x8d,
-  HID_USAGE_PAGE_MSR             = 0x8e,
-  HID_USAGE_PAGE_CAMERA          = 0x90,
-  HID_USAGE_PAGE_ARCADE          = 0x91,
-  HID_USAGE_PAGE_FIDO            = 0xF1D0, // FIDO alliance HID usage page
-  HID_USAGE_PAGE_VENDOR          = 0xFF00 // 0xFF00 - 0xFFFF
+  HID_USAGE_PAGE_DESKTOP                   = 0x01,
+  HID_USAGE_PAGE_SIMULATE                  = 0x02,
+  HID_USAGE_PAGE_VIRTUAL_REALITY           = 0x03,
+  HID_USAGE_PAGE_SPORT                     = 0x04,
+  HID_USAGE_PAGE_GAME                      = 0x05,
+  HID_USAGE_PAGE_GENERIC_DEVICE            = 0x06,
+  HID_USAGE_PAGE_KEYBOARD                  = 0x07,
+  HID_USAGE_PAGE_LED                       = 0x08,
+  HID_USAGE_PAGE_BUTTON                    = 0x09,
+  HID_USAGE_PAGE_ORDINAL                   = 0x0a,
+  HID_USAGE_PAGE_TELEPHONY                 = 0x0b,
+  HID_USAGE_PAGE_CONSUMER                  = 0x0c,
+  HID_USAGE_PAGE_DIGITIZER                 = 0x0d,
+  HID_USAGE_PAGE_PID                       = 0x0f,
+  HID_USAGE_PAGE_UNICODE                   = 0x10,
+  HID_USAGE_PAGE_ALPHA_DISPLAY             = 0x14,
+  HID_USAGE_PAGE_MEDICAL                   = 0x40,
+  HID_USAGE_PAGE_LIGHTING_AND_ILLUMINATION = 0x59,
+  HID_USAGE_PAGE_MONITOR                   = 0x80, // 0x80 - 0x83
+  HID_USAGE_PAGE_POWER                     = 0x84, // 0x084 - 0x87
+  HID_USAGE_PAGE_BARCODE_SCANNER           = 0x8c,
+  HID_USAGE_PAGE_SCALE                     = 0x8d,
+  HID_USAGE_PAGE_MSR                       = 0x8e,
+  HID_USAGE_PAGE_CAMERA                    = 0x90,
+  HID_USAGE_PAGE_ARCADE                    = 0x91,
+  HID_USAGE_PAGE_FIDO                      = 0xF1D0, // FIDO alliance HID usage page
+  HID_USAGE_PAGE_VENDOR                    = 0xFF00  // 0xFF00 - 0xFFFF
 };
 
 /// HID Usage Table - Table 6: Generic Desktop Page
@@ -801,8 +849,7 @@ enum {
 
 /// HID Usage Table: Consumer Page (0x0C)
 /// Only contains controls that supported by Windows (whole list is too long)
-enum
-{
+enum {
   // Generic Control
   HID_USAGE_CONSUMER_CONTROL                           = 0x0001,
 
@@ -858,9 +905,45 @@ enum
   HID_USAGE_CONSUMER_AC_PAN                            = 0x0238,
 };
 
+/// HID Usage Table - Lighting And Illumination Page (0x59)
+enum {
+  HID_USAGE_LIGHTING_LAMP_ARRAY                          = 0x01,
+  HID_USAGE_LIGHTING_LAMP_ARRAY_ATTRIBUTES_REPORT        = 0x02,
+  HID_USAGE_LIGHTING_LAMP_COUNT                          = 0x03,
+  HID_USAGE_LIGHTING_BOUNDING_BOX_WIDTH_IN_MICROMETERS   = 0x04,
+  HID_USAGE_LIGHTING_BOUNDING_BOX_HEIGHT_IN_MICROMETERS  = 0x05,
+  HID_USAGE_LIGHTING_BOUNDING_BOX_DEPTH_IN_MICROMETERS   = 0x06,
+  HID_USAGE_LIGHTING_LAMP_ARRAY_KIND                     = 0x07,
+  HID_USAGE_LIGHTING_MIN_UPDATE_INTERVAL_IN_MICROSECONDS = 0x08,
+  HID_USAGE_LIGHTING_LAMP_ATTRIBUTES_REQUEST_REPORT      = 0x20,
+  HID_USAGE_LIGHTING_LAMP_ID                             = 0x21,
+  HID_USAGE_LIGHTING_LAMP_ATTRIBUTES_RESPONSE_REPORT     = 0x22,
+  HID_USAGE_LIGHTING_POSITION_X_IN_MICROMETERS           = 0x23,
+  HID_USAGE_LIGHTING_POSITION_Y_IN_MICROMETERS           = 0x24,
+  HID_USAGE_LIGHTING_POSITION_Z_IN_MICROMETERS           = 0x25,
+  HID_USAGE_LIGHTING_LAMP_PURPOSES                       = 0x26,
+  HID_USAGE_LIGHTING_UPDATE_LATENCY_IN_MICROSECONDS      = 0x27,
+  HID_USAGE_LIGHTING_RED_LEVEL_COUNT                     = 0x28,
+  HID_USAGE_LIGHTING_GREEN_LEVEL_COUNT                   = 0x29,
+  HID_USAGE_LIGHTING_BLUE_LEVEL_COUNT                    = 0x2A,
+  HID_USAGE_LIGHTING_INTENSITY_LEVEL_COUNT               = 0x2B,
+  HID_USAGE_LIGHTING_IS_PROGRAMMABLE                     = 0x2C,
+  HID_USAGE_LIGHTING_INPUT_BINDING                       = 0x2D,
+  HID_USAGE_LIGHTING_LAMP_MULTI_UPDATE_REPORT            = 0x50,
+  HID_USAGE_LIGHTING_RED_UPDATE_CHANNEL                  = 0x51,
+  HID_USAGE_LIGHTING_GREEN_UPDATE_CHANNEL                = 0x52,
+  HID_USAGE_LIGHTING_BLUE_UPDATE_CHANNEL                 = 0x53,
+  HID_USAGE_LIGHTING_INTENSITY_UPDATE_CHANNEL            = 0x54,
+  HID_USAGE_LIGHTING_LAMP_UPDATE_FLAGS                   = 0x55,
+  HID_USAGE_LIGHTING_LAMP_RANGE_UPDATE_REPORT            = 0x60,
+  HID_USAGE_LIGHTING_LAMP_ID_START                       = 0x61,
+  HID_USAGE_LIGHTING_LAMP_ID_END                         = 0x62,
+  HID_USAGE_LIGHTING_LAMP_ARRAY_CONTROL_REPORT           = 0x70,
+  HID_USAGE_LIGHTING_AUTONOMOUS_MODE                     = 0x71,
+};
+
 /// HID Usage Table: FIDO Alliance Page (0xF1D0)
-enum
-{
+enum {
   HID_USAGE_FIDO_U2FHID   = 0x01, // U2FHID usage for top-level collection
   HID_USAGE_FIDO_DATA_IN  = 0x20, // Raw IN data report
   HID_USAGE_FIDO_DATA_OUT = 0x21  // Raw OUT data report
diff --git a/src/class/hid/hid_device.c b/src/class/hid/hid_device.c
index 5cc5a2488..ef6c7f3af 100644
--- a/src/class/hid/hid_device.c
+++ b/src/class/hid/hid_device.c
@@ -39,92 +39,109 @@
 //--------------------------------------------------------------------+
 // MACRO CONSTANT TYPEDEF
 //--------------------------------------------------------------------+
-typedef struct
-{
+typedef struct {
   uint8_t itf_num;
   uint8_t ep_in;
-  uint8_t ep_out;        // optional Out endpoint
-  uint8_t itf_protocol;  // Boot mouse or keyboard
+  uint8_t ep_out;       // optional Out endpoint
+  uint8_t itf_protocol; // Boot mouse or keyboard
 
+  uint16_t report_desc_len;
   uint8_t protocol_mode; // Boot (0) or Report protocol (1)
   uint8_t idle_rate;     // up to application to handle idle rate
-  uint16_t report_desc_len;
-
-  CFG_TUSB_MEM_ALIGN uint8_t epin_buf[CFG_TUD_HID_EP_BUFSIZE];
-  CFG_TUSB_MEM_ALIGN uint8_t epout_buf[CFG_TUD_HID_EP_BUFSIZE];
 
   // TODO save hid descriptor since host can specifically request this after enumeration
   // Note: HID descriptor may be not available from application after enumeration
-  tusb_hid_descriptor_hid_t const * hid_descriptor;
+  tusb_hid_descriptor_hid_t const *hid_descriptor;
+
+  uint8_t ctrl_buf[CFG_TUD_HID_EP_BUFSIZE];
+  CFG_TUSB_MEM_ALIGN uint8_t epin_buf[CFG_TUD_HID_EP_BUFSIZE];
+  CFG_TUSB_MEM_ALIGN uint8_t epout_buf[CFG_TUD_HID_EP_BUFSIZE];
 } hidd_interface_t;
 
 CFG_TUD_MEM_SECTION tu_static hidd_interface_t _hidd_itf[CFG_TUD_HID];
 
 /*------------- Helpers -------------*/
-static inline uint8_t get_index_by_itfnum(uint8_t itf_num)
-{
-	for (uint8_t i=0; i < CFG_TUD_HID; i++ )
-	{
-		if ( itf_num == _hidd_itf[i].itf_num ) return i;
-	}
+TU_ATTR_ALWAYS_INLINE static inline uint8_t get_index_by_itfnum(uint8_t itf_num) {
+  for (uint8_t i = 0; i < CFG_TUD_HID; i++) {
+    if (itf_num == _hidd_itf[i].itf_num) {
+      return i;
+    }
+  }
+  return 0xFF;
+}
 
-	return 0xFF;
+//--------------------------------------------------------------------+
+// Weak stubs: invoked if no strong implementation is available
+//--------------------------------------------------------------------+
+TU_ATTR_WEAK void tud_hid_set_protocol_cb(uint8_t instance, uint8_t protocol) {
+  (void) instance;
+  (void) protocol;
+}
+
+TU_ATTR_WEAK bool tud_hid_set_idle_cb(uint8_t instance, uint8_t idle_rate) {
+  (void) instance;
+  (void) idle_rate;
+  return true;
+}
+
+TU_ATTR_WEAK void tud_hid_report_complete_cb(uint8_t instance, uint8_t const* report, uint16_t len) {
+  (void) instance;
+  (void) report;
+  (void) len;
+}
+
+// Invoked when a transfer wasn't successful
+TU_ATTR_WEAK void tud_hid_report_failed_cb(uint8_t instance, hid_report_type_t report_type, uint8_t const* report, uint16_t xferred_bytes) {
+  (void) instance;
+  (void) report_type;
+  (void) report;
+  (void) xferred_bytes;
 }
 
 //--------------------------------------------------------------------+
 // APPLICATION API
 //--------------------------------------------------------------------+
-bool tud_hid_n_ready(uint8_t instance)
-{
+bool tud_hid_n_ready(uint8_t instance) {
   uint8_t const rhport = 0;
   uint8_t const ep_in = _hidd_itf[instance].ep_in;
   return tud_ready() && (ep_in != 0) && !usbd_edpt_busy(rhport, ep_in);
 }
 
-bool tud_hid_n_report(uint8_t instance, uint8_t report_id, void const* report, uint16_t len)
-{
+bool tud_hid_n_report(uint8_t instance, uint8_t report_id, void const *report, uint16_t len) {
   uint8_t const rhport = 0;
-  hidd_interface_t * p_hid = &_hidd_itf[instance];
+  hidd_interface_t *p_hid = &_hidd_itf[instance];
 
   // claim endpoint
-  TU_VERIFY( usbd_edpt_claim(rhport, p_hid->ep_in) );
+  TU_VERIFY(usbd_edpt_claim(rhport, p_hid->ep_in));
 
   // prepare data
-  if (report_id)
-  {
+  if (report_id) {
     p_hid->epin_buf[0] = report_id;
-    TU_VERIFY(0 == tu_memcpy_s(p_hid->epin_buf+1, CFG_TUD_HID_EP_BUFSIZE-1, report, len));
+    TU_VERIFY(0 == tu_memcpy_s(p_hid->epin_buf + 1, CFG_TUD_HID_EP_BUFSIZE - 1, report, len));
     len++;
-  }else
-  {
+  } else {
     TU_VERIFY(0 == tu_memcpy_s(p_hid->epin_buf, CFG_TUD_HID_EP_BUFSIZE, report, len));
   }
 
   return usbd_edpt_xfer(rhport, p_hid->ep_in, p_hid->epin_buf, len);
 }
 
-uint8_t tud_hid_n_interface_protocol(uint8_t instance)
-{
+uint8_t tud_hid_n_interface_protocol(uint8_t instance) {
   return _hidd_itf[instance].itf_protocol;
 }
 
-uint8_t tud_hid_n_get_protocol(uint8_t instance)
-{
+uint8_t tud_hid_n_get_protocol(uint8_t instance) {
   return _hidd_itf[instance].protocol_mode;
 }
 
-bool tud_hid_n_keyboard_report(uint8_t instance, uint8_t report_id, uint8_t modifier, uint8_t keycode[6])
-{
+bool tud_hid_n_keyboard_report(uint8_t instance, uint8_t report_id, uint8_t modifier, const uint8_t keycode[6]) {
   hid_keyboard_report_t report;
-
   report.modifier = modifier;
   report.reserved = 0;
 
-  if ( keycode )
-  {
+  if (keycode) {
     memcpy(report.keycode, keycode, sizeof(report.keycode));
-  }else
-  {
+  } else {
     tu_memclr(report.keycode, 6);
   }
 
@@ -132,45 +149,41 @@ bool tud_hid_n_keyboard_report(uint8_t instance, uint8_t report_id, uint8_t modi
 }
 
 bool tud_hid_n_mouse_report(uint8_t instance, uint8_t report_id,
-                            uint8_t buttons, int8_t x, int8_t y, int8_t vertical, int8_t horizontal)
-{
-  hid_mouse_report_t report =
-  {
+                            uint8_t buttons, int8_t x, int8_t y, int8_t vertical, int8_t horizontal) {
+  hid_mouse_report_t report = {
     .buttons = buttons,
-    .x       = x,
-    .y       = y,
-    .wheel   = vertical,
-    .pan     = horizontal
+    .x = x,
+    .y = y,
+    .wheel = vertical,
+    .pan = horizontal
   };
 
   return tud_hid_n_report(instance, report_id, &report, sizeof(report));
 }
 
-bool tud_hid_n_abs_mouse_report(uint8_t instance, uint8_t report_id, uint8_t buttons, int16_t x, int16_t y, int8_t vertical, int8_t horizontal)
-{
-  hid_abs_mouse_report_t report =
-  {
+bool tud_hid_n_abs_mouse_report(uint8_t instance, uint8_t report_id,
+                                uint8_t buttons, int16_t x, int16_t y, int8_t vertical, int8_t horizontal) {
+  hid_abs_mouse_report_t report = {
     .buttons = buttons,
-    .x       = x,
-    .y       = y,
-    .wheel   = vertical,
-    .pan     = horizontal
+    .x = x,
+    .y = y,
+    .wheel = vertical,
+    .pan = horizontal
   };
   return tud_hid_n_report(instance, report_id, &report, sizeof(report));
 }
 
 bool tud_hid_n_gamepad_report(uint8_t instance, uint8_t report_id,
                               int8_t x, int8_t y, int8_t z, int8_t rz, int8_t rx, int8_t ry, uint8_t hat, uint32_t buttons) {
-  hid_gamepad_report_t report =
-  {
-    .x       = x,
-    .y       = y,
-    .z       = z,
-    .rz      = rz,
-    .rx      = rx,
-    .ry      = ry,
-    .hat     = hat,
-    .buttons = buttons,
+  hid_gamepad_report_t report = {
+      .x = x,
+      .y = y,
+      .z = z,
+      .rz = rz,
+      .rx = rx,
+      .ry = ry,
+      .hat = hat,
+      .buttons = buttons,
   };
 
   return tud_hid_n_report(instance, report_id, &report, sizeof(report));
@@ -187,59 +200,54 @@ bool hidd_deinit(void) {
   return true;
 }
 
-void hidd_reset(uint8_t rhport)
-{
-  (void) rhport;
+void hidd_reset(uint8_t rhport) {
+  (void)rhport;
   tu_memclr(_hidd_itf, sizeof(_hidd_itf));
 }
 
-uint16_t hidd_open(uint8_t rhport, tusb_desc_interface_t const * desc_itf, uint16_t max_len)
- {
+uint16_t hidd_open(uint8_t rhport, tusb_desc_interface_t const *desc_itf, uint16_t max_len) {
   TU_VERIFY(TUSB_CLASS_HID == desc_itf->bInterfaceClass, 0);
 
   // len = interface + hid + n*endpoints
-  uint16_t const drv_len =
-      (uint16_t) (sizeof(tusb_desc_interface_t) + sizeof(tusb_hid_descriptor_hid_t) +
+  uint16_t const drv_len = (uint16_t) (sizeof(tusb_desc_interface_t) + sizeof(tusb_hid_descriptor_hid_t) +
                                        desc_itf->bNumEndpoints * sizeof(tusb_desc_endpoint_t));
   TU_ASSERT(max_len >= drv_len, 0);
 
   // Find available interface
-  hidd_interface_t * p_hid = NULL;
+  hidd_interface_t *p_hid = NULL;
   uint8_t hid_id;
-  for(hid_id=0; hid_id<CFG_TUD_HID; hid_id++)
-  {
-    if ( _hidd_itf[hid_id].ep_in == 0 )
-    {
+  for (hid_id = 0; hid_id < CFG_TUD_HID; hid_id++) {
+    if (_hidd_itf[hid_id].ep_in == 0) {
       p_hid = &_hidd_itf[hid_id];
       break;
     }
   }
   TU_ASSERT(p_hid, 0);
 
-  uint8_t const *p_desc = (uint8_t const *) desc_itf;
+  uint8_t const *p_desc = (uint8_t const *)desc_itf;
 
   //------------- HID descriptor -------------//
   p_desc = tu_desc_next(p_desc);
   TU_ASSERT(HID_DESC_TYPE_HID == tu_desc_type(p_desc), 0);
-  p_hid->hid_descriptor = (tusb_hid_descriptor_hid_t const *) p_desc;
+  p_hid->hid_descriptor = (tusb_hid_descriptor_hid_t const *)p_desc;
 
   //------------- Endpoint Descriptor -------------//
   p_desc = tu_desc_next(p_desc);
   TU_ASSERT(usbd_open_edpt_pair(rhport, p_desc, desc_itf->bNumEndpoints, TUSB_XFER_INTERRUPT, &p_hid->ep_out, &p_hid->ep_in), 0);
 
-  if ( desc_itf->bInterfaceSubClass == HID_SUBCLASS_BOOT ) p_hid->itf_protocol = desc_itf->bInterfaceProtocol;
+  if (desc_itf->bInterfaceSubClass == HID_SUBCLASS_BOOT) {
+    p_hid->itf_protocol = desc_itf->bInterfaceProtocol;
+  }
 
   p_hid->protocol_mode = HID_PROTOCOL_REPORT; // Per Specs: default is report mode
-  p_hid->itf_num       = desc_itf->bInterfaceNumber;
+  p_hid->itf_num = desc_itf->bInterfaceNumber;
 
   // Use offsetof to avoid pointer to the odd/misaligned address
-  p_hid->report_desc_len = tu_unaligned_read16((uint8_t const*) p_hid->hid_descriptor + offsetof(tusb_hid_descriptor_hid_t, wReportLength));
+  p_hid->report_desc_len = tu_unaligned_read16((uint8_t const *)p_hid->hid_descriptor + offsetof(tusb_hid_descriptor_hid_t, wReportLength));
 
   // Prepare for output endpoint
-  if (p_hid->ep_out)
-  {
-    if ( !usbd_edpt_xfer(rhport, p_hid->ep_out, p_hid->epout_buf, sizeof(p_hid->epout_buf)) )
-    {
+  if (p_hid->ep_out) {
+    if (!usbd_edpt_xfer(rhport, p_hid->ep_out, p_hid->epout_buf, sizeof(p_hid->epout_buf))) {
       TU_LOG_FAILED();
       TU_BREAKPOINT();
     }
@@ -251,177 +259,146 @@ uint16_t hidd_open(uint8_t rhport, tusb_desc_interface_t const * desc_itf, uint1
 // 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 hidd_control_xfer_cb (uint8_t rhport, uint8_t stage, tusb_control_request_t const * request)
-{
+bool hidd_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb_control_request_t const *request) {
   TU_VERIFY(request->bmRequestType_bit.recipient == TUSB_REQ_RCPT_INTERFACE);
 
-  uint8_t const hid_itf = get_index_by_itfnum((uint8_t) request->wIndex);
+  uint8_t const hid_itf = get_index_by_itfnum((uint8_t)request->wIndex);
   TU_VERIFY(hid_itf < CFG_TUD_HID);
 
-  hidd_interface_t* p_hid = &_hidd_itf[hid_itf];
+  hidd_interface_t *p_hid = &_hidd_itf[hid_itf];
 
-  if (request->bmRequestType_bit.type == TUSB_REQ_TYPE_STANDARD)
-  {
+  if (request->bmRequestType_bit.type == TUSB_REQ_TYPE_STANDARD) {
     //------------- STD Request -------------//
-    if ( stage == CONTROL_STAGE_SETUP )
-    {
-      uint8_t const desc_type  = tu_u16_high(request->wValue);
-      //uint8_t const desc_index = tu_u16_low (request->wValue);
+    if (stage == CONTROL_STAGE_SETUP) {
+      uint8_t const desc_type = tu_u16_high(request->wValue);
+      // uint8_t const desc_index = tu_u16_low (request->wValue);
 
-      if (request->bRequest == TUSB_REQ_GET_DESCRIPTOR && desc_type == HID_DESC_TYPE_HID)
-      {
+      if (request->bRequest == TUSB_REQ_GET_DESCRIPTOR && desc_type == HID_DESC_TYPE_HID) {
         TU_VERIFY(p_hid->hid_descriptor);
-        TU_VERIFY(tud_control_xfer(rhport, request, (void*)(uintptr_t) p_hid->hid_descriptor, p_hid->hid_descriptor->bLength));
-      }
-      else if (request->bRequest == TUSB_REQ_GET_DESCRIPTOR && desc_type == HID_DESC_TYPE_REPORT)
-      {
-        uint8_t const * desc_report = tud_hid_descriptor_report_cb(hid_itf);
-        tud_control_xfer(rhport, request, (void*)(uintptr_t) desc_report, p_hid->report_desc_len);
-      }
-      else
-      {
+        TU_VERIFY(tud_control_xfer(rhport, request, (void *)(uintptr_t)p_hid->hid_descriptor, p_hid->hid_descriptor->bLength));
+      } else if (request->bRequest == TUSB_REQ_GET_DESCRIPTOR && desc_type == HID_DESC_TYPE_REPORT) {
+        uint8_t const *desc_report = tud_hid_descriptor_report_cb(hid_itf);
+        tud_control_xfer(rhport, request, (void *)(uintptr_t)desc_report, p_hid->report_desc_len);
+      } else {
         return false; // stall unsupported request
       }
     }
-  }
-  else if (request->bmRequestType_bit.type == TUSB_REQ_TYPE_CLASS)
-  {
+  } else if (request->bmRequestType_bit.type == TUSB_REQ_TYPE_CLASS) {
     //------------- Class Specific Request -------------//
-    switch( request->bRequest )
-    {
+    switch (request->bRequest) {
       case HID_REQ_CONTROL_GET_REPORT:
-        if ( stage == CONTROL_STAGE_SETUP )
-        {
+        if (stage == CONTROL_STAGE_SETUP) {
           uint8_t const report_type = tu_u16_high(request->wValue);
-          uint8_t const report_id   = tu_u16_low(request->wValue);
+          uint8_t const report_id = tu_u16_low(request->wValue);
 
-          uint8_t* report_buf = p_hid->epin_buf;
+          uint8_t* report_buf = p_hid->ctrl_buf;
           uint16_t req_len = tu_min16(request->wLength, CFG_TUD_HID_EP_BUFSIZE);
-
           uint16_t xferlen = 0;
 
           // If host request a specific Report ID, add ID to as 1 byte of response
-          if ( (report_id != HID_REPORT_TYPE_INVALID) && (req_len > 1) )
-          {
+          if ((report_id != HID_REPORT_TYPE_INVALID) && (req_len > 1)) {
             *report_buf++ = report_id;
             req_len--;
-
             xferlen++;
           }
 
           xferlen += tud_hid_get_report_cb(hid_itf, report_id, (hid_report_type_t) report_type, report_buf, req_len);
-          TU_ASSERT( xferlen > 0 );
+          TU_ASSERT(xferlen > 0);
 
-          tud_control_xfer(rhport, request, p_hid->epin_buf, xferlen);
+          tud_control_xfer(rhport, request, p_hid->ctrl_buf, xferlen);
         }
-      break;
+        break;
 
-      case  HID_REQ_CONTROL_SET_REPORT:
-        if ( stage == CONTROL_STAGE_SETUP )
-        {
-          TU_VERIFY(request->wLength <= sizeof(p_hid->epout_buf));
-          tud_control_xfer(rhport, request, p_hid->epout_buf, request->wLength);
-        }
-        else if ( stage == CONTROL_STAGE_ACK )
-        {
+      case HID_REQ_CONTROL_SET_REPORT:
+        if (stage == CONTROL_STAGE_SETUP) {
+          TU_VERIFY(request->wLength <= sizeof(p_hid->ctrl_buf));
+          tud_control_xfer(rhport, request, p_hid->ctrl_buf, request->wLength);
+        } else if (stage == CONTROL_STAGE_ACK) {
           uint8_t const report_type = tu_u16_high(request->wValue);
-          uint8_t const report_id   = tu_u16_low(request->wValue);
+          uint8_t const report_id = tu_u16_low(request->wValue);
 
-          uint8_t const* report_buf = p_hid->epout_buf;
+          uint8_t const* report_buf = p_hid->ctrl_buf;
           uint16_t report_len = tu_min16(request->wLength, CFG_TUD_HID_EP_BUFSIZE);
 
           // If host request a specific Report ID, extract report ID in buffer before invoking callback
-          if ( (report_id != HID_REPORT_TYPE_INVALID) && (report_len > 1) && (report_id == report_buf[0]) )
-          {
+          if ((report_id != HID_REPORT_TYPE_INVALID) && (report_len > 1) && (report_id == report_buf[0])) {
             report_buf++;
             report_len--;
           }
 
           tud_hid_set_report_cb(hid_itf, report_id, (hid_report_type_t) report_type, report_buf, report_len);
         }
-      break;
+        break;
 
       case HID_REQ_CONTROL_SET_IDLE:
-        if ( stage == CONTROL_STAGE_SETUP )
-        {
+        if (stage == CONTROL_STAGE_SETUP) {
           p_hid->idle_rate = tu_u16_high(request->wValue);
-          if ( tud_hid_set_idle_cb )
-          {
-            // stall request if callback return false
-            TU_VERIFY( tud_hid_set_idle_cb( hid_itf, p_hid->idle_rate) );
-          }
-
+          TU_VERIFY(tud_hid_set_idle_cb(hid_itf, p_hid->idle_rate)); // stall if false
           tud_control_status(rhport, request);
         }
-      break;
+        break;
 
       case HID_REQ_CONTROL_GET_IDLE:
-        if ( stage == CONTROL_STAGE_SETUP )
-        {
+        if (stage == CONTROL_STAGE_SETUP) {
           // TODO idle rate of report
           tud_control_xfer(rhport, request, &p_hid->idle_rate, 1);
         }
-      break;
+        break;
 
       case HID_REQ_CONTROL_GET_PROTOCOL:
-        if ( stage == CONTROL_STAGE_SETUP )
-        {
+        if (stage == CONTROL_STAGE_SETUP) {
           tud_control_xfer(rhport, request, &p_hid->protocol_mode, 1);
         }
-      break;
+        break;
 
       case HID_REQ_CONTROL_SET_PROTOCOL:
-        if ( stage == CONTROL_STAGE_SETUP )
-        {
+        if (stage == CONTROL_STAGE_SETUP) {
           tud_control_status(rhport, request);
-        }
-        else if ( stage == CONTROL_STAGE_ACK )
-        {
+        } else if (stage == CONTROL_STAGE_ACK) {
           p_hid->protocol_mode = (uint8_t) request->wValue;
-          if (tud_hid_set_protocol_cb)
-          {
-            tud_hid_set_protocol_cb(hid_itf, p_hid->protocol_mode);
-          }
+          tud_hid_set_protocol_cb(hid_itf, p_hid->protocol_mode);
         }
-      break;
+        break;
 
-      default: return false; // stall unsupported request
+      default:
+        return false; // stall unsupported request
     }
-  }else
-  {
+  } else {
     return false; // stall unsupported request
   }
 
   return true;
 }
 
-bool hidd_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint32_t xferred_bytes)
-{
-  (void) result;
-
+bool hidd_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint32_t xferred_bytes) {
   uint8_t instance = 0;
-  hidd_interface_t * p_hid = _hidd_itf;
+  hidd_interface_t *p_hid = _hidd_itf;
 
   // Identify which interface to use
-  for (instance = 0; instance < CFG_TUD_HID; instance++)
-  {
+  for (instance = 0; instance < CFG_TUD_HID; instance++) {
     p_hid = &_hidd_itf[instance];
-    if ( (ep_addr == p_hid->ep_out) || (ep_addr == p_hid->ep_in) ) break;
+    if ((ep_addr == p_hid->ep_out) || (ep_addr == p_hid->ep_in)) {
+      break;
+    }
   }
   TU_ASSERT(instance < CFG_TUD_HID);
 
-  // Sent report successfully
-  if (ep_addr == p_hid->ep_in)
-  {
-    if (tud_hid_report_complete_cb)
-    {
+  if (ep_addr == p_hid->ep_in) {
+    // Input report
+    if (XFER_RESULT_SUCCESS == result) {
       tud_hid_report_complete_cb(instance, p_hid->epin_buf, (uint16_t) xferred_bytes);
+    } else {
+      tud_hid_report_failed_cb(instance, HID_REPORT_TYPE_INPUT, p_hid->epin_buf, (uint16_t) xferred_bytes);
     }
-  }
-  // Received report
-  else if (ep_addr == p_hid->ep_out)
-  {
-    tud_hid_set_report_cb(instance, 0, HID_REPORT_TYPE_INVALID, p_hid->epout_buf, (uint16_t) xferred_bytes);
+  } else {
+    // Output report
+    if (XFER_RESULT_SUCCESS == result) {
+      tud_hid_set_report_cb(instance, 0, HID_REPORT_TYPE_OUTPUT, p_hid->epout_buf, (uint16_t)xferred_bytes);
+    } else {
+      tud_hid_report_failed_cb(instance, HID_REPORT_TYPE_OUTPUT, p_hid->epout_buf, (uint16_t) xferred_bytes);
+    }
+
+    // prepare for new transfer
     TU_ASSERT(usbd_edpt_xfer(rhport, p_hid->ep_out, p_hid->epout_buf, sizeof(p_hid->epout_buf)));
   }
 
diff --git a/src/class/hid/hid_device.h b/src/class/hid/hid_device.h
index 040cad162..ab2e27373 100644
--- a/src/class/hid/hid_device.h
+++ b/src/class/hid/hid_device.h
@@ -24,8 +24,8 @@
  * This file is part of the TinyUSB stack.
  */
 
-#ifndef _TUSB_HID_DEVICE_H_
-#define _TUSB_HID_DEVICE_H_
+#ifndef TUSB_HID_DEVICE_H_
+#define TUSB_HID_DEVICE_H_
 
 #include "hid.h"
 
@@ -48,8 +48,7 @@
 #endif
 
 //--------------------------------------------------------------------+
-// Application API (Multiple Instances)
-// CFG_TUD_HID > 1
+// Application API (Multiple Instances) i.e. CFG_TUD_HID > 1
 //--------------------------------------------------------------------+
 
 // Check if the interface is ready to use
@@ -66,7 +65,7 @@ bool tud_hid_n_report(uint8_t instance, uint8_t report_id, void const* report, u
 
 // KEYBOARD: convenient helper to send keyboard report if application
 // use template layout report as defined by hid_keyboard_report_t
-bool tud_hid_n_keyboard_report(uint8_t instance, uint8_t report_id, uint8_t modifier, uint8_t keycode[6]);
+bool tud_hid_n_keyboard_report(uint8_t instance, uint8_t report_id, uint8_t modifier, const uint8_t keycode[6]);
 
 // MOUSE: convenient helper to send mouse report if application
 // use template layout report as defined by hid_mouse_report_t
@@ -76,12 +75,6 @@ bool tud_hid_n_mouse_report(uint8_t instance, uint8_t report_id, uint8_t buttons
 // use template layout report as defined by hid_abs_mouse_report_t
 bool tud_hid_n_abs_mouse_report(uint8_t instance, uint8_t report_id, uint8_t buttons, int16_t x, int16_t y, int8_t vertical, int8_t horizontal);
 
-
-static inline bool tud_hid_abs_mouse_report(uint8_t report_id, uint8_t buttons, int16_t x, int16_t y, int8_t vertical, int8_t horizontal)
-{
-  return tud_hid_n_abs_mouse_report(0, report_id, buttons, x, y, vertical, horizontal);
-}
-
 // Gamepad: convenient helper to send gamepad report if application
 // use template layout report TUD_HID_REPORT_DESC_GAMEPAD
 bool tud_hid_n_gamepad_report(uint8_t instance, uint8_t report_id, int8_t x, int8_t y, int8_t z, int8_t rz, int8_t rx, int8_t ry, uint8_t hat, uint32_t buttons);
@@ -89,16 +82,40 @@ bool tud_hid_n_gamepad_report(uint8_t instance, uint8_t report_id, int8_t x, int
 //--------------------------------------------------------------------+
 // Application API (Single Port)
 //--------------------------------------------------------------------+
-static inline bool    tud_hid_ready(void);
-static inline uint8_t tud_hid_interface_protocol(void);
-static inline uint8_t tud_hid_get_protocol(void);
-static inline bool    tud_hid_report(uint8_t report_id, void const* report, uint16_t len);
-static inline bool    tud_hid_keyboard_report(uint8_t report_id, uint8_t modifier, uint8_t keycode[6]);
-static inline bool    tud_hid_mouse_report(uint8_t report_id, uint8_t buttons, int8_t x, int8_t y, int8_t vertical, int8_t horizontal);
-static inline bool    tud_hid_gamepad_report(uint8_t report_id, int8_t x, int8_t y, int8_t z, int8_t rz, int8_t rx, int8_t ry, uint8_t hat, uint32_t buttons);
+TU_ATTR_ALWAYS_INLINE static inline bool tud_hid_ready(void) {
+  return tud_hid_n_ready(0);
+}
+
+TU_ATTR_ALWAYS_INLINE static inline uint8_t tud_hid_interface_protocol(void) {
+  return tud_hid_n_interface_protocol(0);
+}
+
+TU_ATTR_ALWAYS_INLINE static inline uint8_t tud_hid_get_protocol(void) {
+  return tud_hid_n_get_protocol(0);
+}
+
+TU_ATTR_ALWAYS_INLINE static inline bool tud_hid_report(uint8_t report_id, void const* report, uint16_t len) {
+  return tud_hid_n_report(0, report_id, report, len);
+}
+
+TU_ATTR_ALWAYS_INLINE static inline bool tud_hid_keyboard_report(uint8_t report_id, uint8_t modifier, const uint8_t keycode[6]) {
+  return tud_hid_n_keyboard_report(0, report_id, modifier, keycode);
+}
+
+TU_ATTR_ALWAYS_INLINE static inline bool tud_hid_mouse_report(uint8_t report_id, uint8_t buttons, int8_t x, int8_t y, int8_t vertical, int8_t horizontal) {
+  return tud_hid_n_mouse_report(0, report_id, buttons, x, y, vertical, horizontal);
+}
+
+TU_ATTR_ALWAYS_INLINE static inline bool tud_hid_abs_mouse_report(uint8_t report_id, uint8_t buttons, int16_t x, int16_t y, int8_t vertical, int8_t horizontal) {
+  return tud_hid_n_abs_mouse_report(0, report_id, buttons, x, y, vertical, horizontal);
+}
+
+TU_ATTR_ALWAYS_INLINE static inline bool tud_hid_gamepad_report(uint8_t report_id, int8_t x, int8_t y, int8_t z, int8_t rz, int8_t rx, int8_t ry, uint8_t hat, uint32_t buttons) {
+  return tud_hid_n_gamepad_report(0, report_id, x, y, z, rz, rx, ry, hat, buttons);
+}
 
 //--------------------------------------------------------------------+
-// Callbacks (Weak is optional)
+// Application Callbacks
 //--------------------------------------------------------------------+
 
 // Invoked when received GET HID REPORT DESCRIPTOR request
@@ -111,61 +128,25 @@ uint8_t const * tud_hid_descriptor_report_cb(uint8_t instance);
 uint16_t tud_hid_get_report_cb(uint8_t instance, uint8_t report_id, hid_report_type_t report_type, uint8_t* buffer, uint16_t reqlen);
 
 // Invoked when received SET_REPORT control request or
-// received data on OUT endpoint ( Report ID = 0, Type = 0 )
+// received data on OUT endpoint (Report ID = 0, Type = OUTPUT)
 void tud_hid_set_report_cb(uint8_t instance, uint8_t report_id, hid_report_type_t report_type, uint8_t const* buffer, uint16_t bufsize);
 
 // Invoked when received SET_PROTOCOL request
 // protocol is either HID_PROTOCOL_BOOT (0) or HID_PROTOCOL_REPORT (1)
-TU_ATTR_WEAK void tud_hid_set_protocol_cb(uint8_t instance, uint8_t protocol);
+void tud_hid_set_protocol_cb(uint8_t instance, uint8_t protocol);
 
 // Invoked when received SET_IDLE request. return false will stall the request
-// - Idle Rate = 0 : only send report if there is changes, i.e skip duplication
+// - Idle Rate = 0 : only send report if there is changes, i.e. skip duplication
 // - Idle Rate > 0 : skip duplication, but send at least 1 report every idle rate (in unit of 4 ms).
-TU_ATTR_WEAK bool tud_hid_set_idle_cb(uint8_t instance, uint8_t idle_rate);
+bool tud_hid_set_idle_cb(uint8_t instance, uint8_t idle_rate);
 
 // Invoked when sent REPORT successfully to host
 // Application can use this to send the next report
 // Note: For composite reports, report[0] is report ID
-TU_ATTR_WEAK void tud_hid_report_complete_cb(uint8_t instance, uint8_t const* report, uint16_t len);
+void tud_hid_report_complete_cb(uint8_t instance, uint8_t const* report, uint16_t len);
 
-
-//--------------------------------------------------------------------+
-// Inline Functions
-//--------------------------------------------------------------------+
-static inline bool tud_hid_ready(void)
-{
-  return tud_hid_n_ready(0);
-}
-
-static inline uint8_t tud_hid_interface_protocol(void)
-{
-  return tud_hid_n_interface_protocol(0);
-}
-
-static inline uint8_t tud_hid_get_protocol(void)
-{
-  return tud_hid_n_get_protocol(0);
-}
-
-static inline bool tud_hid_report(uint8_t report_id, void const* report, uint16_t len)
-{
-  return tud_hid_n_report(0, report_id, report, len);
-}
-
-static inline bool tud_hid_keyboard_report(uint8_t report_id, uint8_t modifier, uint8_t keycode[6])
-{
-  return tud_hid_n_keyboard_report(0, report_id, modifier, keycode);
-}
-
-static inline bool tud_hid_mouse_report(uint8_t report_id, uint8_t buttons, int8_t x, int8_t y, int8_t vertical, int8_t horizontal)
-{
-  return tud_hid_n_mouse_report(0, report_id, buttons, x, y, vertical, horizontal);
-}
-
-static inline bool  tud_hid_gamepad_report(uint8_t report_id, int8_t x, int8_t y, int8_t z, int8_t rz, int8_t rx, int8_t ry, uint8_t hat, uint32_t buttons)
-{
-  return tud_hid_n_gamepad_report(0, report_id, x, y, z, rz, rx, ry, hat, buttons);
-}
+// Invoked when a transfer wasn't successful
+void tud_hid_report_failed_cb(uint8_t instance, hid_report_type_t report_type, uint8_t const* report, uint16_t xferred_bytes);
 
 /* --------------------------------------------------------------------+
  * HID Report Descriptor Template
@@ -461,6 +442,178 @@ static inline bool  tud_hid_gamepad_report(uint8_t report_id, int8_t x, int8_t y
       HID_OUTPUT      ( HID_DATA | HID_VARIABLE | HID_ABSOLUTE  ),\
     HID_COLLECTION_END \
 
+// HID Lighting and Illumination Report Descriptor Template
+// - 1st parameter is report id (required)
+//   Creates 6 report ids for lighting HID usages in the following order:
+//     report_id+0: HID_USAGE_LIGHTING_LAMP_ARRAY_ATTRIBUTES_REPORT
+//     report_id+1: HID_USAGE_LIGHTING_LAMP_ATTRIBUTES_REQUEST_REPORT
+//     report_id+2: HID_USAGE_LIGHTING_LAMP_ATTRIBUTES_RESPONSE_REPORT
+//     report_id+3: HID_USAGE_LIGHTING_LAMP_MULTI_UPDATE_REPORT
+//     report_id+4: HID_USAGE_LIGHTING_LAMP_RANGE_UPDATE_REPORT
+//     report_id+5: HID_USAGE_LIGHTING_LAMP_ARRAY_CONTROL_REPORT
+#define TUD_HID_REPORT_DESC_LIGHTING(report_id) \
+  HID_USAGE_PAGE ( HID_USAGE_PAGE_LIGHTING_AND_ILLUMINATION ),\
+  HID_USAGE      ( HID_USAGE_LIGHTING_LAMP_ARRAY            ),\
+  HID_COLLECTION ( HID_COLLECTION_APPLICATION               ),\
+    /* Lamp Array Attributes Report */ \
+    HID_REPORT_ID (report_id                                    ) \
+    HID_USAGE ( HID_USAGE_LIGHTING_LAMP_ARRAY_ATTRIBUTES_REPORT ),\
+    HID_COLLECTION ( HID_COLLECTION_LOGICAL                     ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_LAMP_COUNT                          ),\
+      HID_LOGICAL_MIN   ( 0                                                      ),\
+      HID_LOGICAL_MAX_N ( 65535, 3                                               ),\
+      HID_REPORT_SIZE   ( 16                                                     ),\
+      HID_REPORT_COUNT  ( 1                                                      ),\
+      HID_FEATURE       ( HID_CONSTANT | HID_VARIABLE | HID_ABSOLUTE             ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_BOUNDING_BOX_WIDTH_IN_MICROMETERS   ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_BOUNDING_BOX_HEIGHT_IN_MICROMETERS  ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_BOUNDING_BOX_DEPTH_IN_MICROMETERS   ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_LAMP_ARRAY_KIND                     ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_MIN_UPDATE_INTERVAL_IN_MICROSECONDS ),\
+      HID_LOGICAL_MIN   ( 0                                                      ),\
+      HID_LOGICAL_MAX_N ( 2147483647, 3                                          ),\
+      HID_REPORT_SIZE   ( 32                                                     ),\
+      HID_REPORT_COUNT  ( 5                                                      ),\
+      HID_FEATURE       ( HID_CONSTANT | HID_VARIABLE | HID_ABSOLUTE             ),\
+    HID_COLLECTION_END ,\
+    /* Lamp Attributes Request Report */ \
+    HID_REPORT_ID       ( report_id + 1                                     ) \
+    HID_USAGE           ( HID_USAGE_LIGHTING_LAMP_ATTRIBUTES_REQUEST_REPORT ),\
+    HID_COLLECTION      ( HID_COLLECTION_LOGICAL                            ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_LAMP_ID             ),\
+      HID_LOGICAL_MIN   ( 0                                      ),\
+      HID_LOGICAL_MAX_N ( 65535, 3                               ),\
+      HID_REPORT_SIZE   ( 16                                     ),\
+      HID_REPORT_COUNT  ( 1                                      ),\
+      HID_FEATURE       ( HID_DATA | HID_VARIABLE | HID_ABSOLUTE ),\
+    HID_COLLECTION_END ,\
+    /* Lamp Attributes Response Report */ \
+    HID_REPORT_ID       ( report_id + 2                                      ) \
+    HID_USAGE           ( HID_USAGE_LIGHTING_LAMP_ATTRIBUTES_RESPONSE_REPORT ),\
+    HID_COLLECTION      ( HID_COLLECTION_LOGICAL                             ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_LAMP_ID                        ),\
+      HID_LOGICAL_MIN   ( 0                                                 ),\
+      HID_LOGICAL_MAX_N ( 65535, 3                                          ),\
+      HID_REPORT_SIZE   ( 16                                                ),\
+      HID_REPORT_COUNT  ( 1                                                 ),\
+      HID_FEATURE       ( HID_DATA | HID_VARIABLE | HID_ABSOLUTE            ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_POSITION_X_IN_MICROMETERS      ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_POSITION_Y_IN_MICROMETERS      ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_POSITION_Z_IN_MICROMETERS      ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_UPDATE_LATENCY_IN_MICROSECONDS ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_LAMP_PURPOSES                  ),\
+      HID_LOGICAL_MIN   ( 0                                                 ),\
+      HID_LOGICAL_MAX_N ( 2147483647, 3                                     ),\
+      HID_REPORT_SIZE   ( 32                                                ),\
+      HID_REPORT_COUNT  ( 5                                                 ),\
+      HID_FEATURE       ( HID_DATA | HID_VARIABLE | HID_ABSOLUTE            ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_RED_LEVEL_COUNT                ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_GREEN_LEVEL_COUNT              ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_BLUE_LEVEL_COUNT               ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_INTENSITY_LEVEL_COUNT          ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_IS_PROGRAMMABLE                ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_INPUT_BINDING                  ),\
+      HID_LOGICAL_MIN   ( 0                                                 ),\
+      HID_LOGICAL_MAX_N ( 255, 2                                            ),\
+      HID_REPORT_SIZE   ( 8                                                 ),\
+      HID_REPORT_COUNT  ( 6                                                 ),\
+      HID_FEATURE       ( HID_DATA | HID_VARIABLE | HID_ABSOLUTE            ),\
+    HID_COLLECTION_END ,\
+    /* Lamp Multi-Update Report */ \
+    HID_REPORT_ID       ( report_id + 3                               ) \
+    HID_USAGE           ( HID_USAGE_LIGHTING_LAMP_MULTI_UPDATE_REPORT ),\
+    HID_COLLECTION      ( HID_COLLECTION_LOGICAL                      ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_LAMP_COUNT               ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_LAMP_UPDATE_FLAGS        ),\
+      HID_LOGICAL_MIN   ( 0                                           ),\
+      HID_LOGICAL_MAX   ( 8                                           ),\
+      HID_REPORT_SIZE   ( 8                                           ),\
+      HID_REPORT_COUNT  ( 2                                           ),\
+      HID_FEATURE       ( HID_DATA | HID_VARIABLE | HID_ABSOLUTE      ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_LAMP_ID                  ),\
+      HID_LOGICAL_MIN   ( 0                                           ),\
+      HID_LOGICAL_MAX_N ( 65535, 3                                    ),\
+      HID_REPORT_SIZE   ( 16                                          ),\
+      HID_REPORT_COUNT  ( 8                                           ),\
+      HID_FEATURE       ( HID_DATA | HID_VARIABLE | HID_ABSOLUTE      ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_RED_UPDATE_CHANNEL       ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_GREEN_UPDATE_CHANNEL     ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_BLUE_UPDATE_CHANNEL      ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_INTENSITY_UPDATE_CHANNEL ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_RED_UPDATE_CHANNEL       ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_GREEN_UPDATE_CHANNEL     ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_BLUE_UPDATE_CHANNEL      ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_INTENSITY_UPDATE_CHANNEL ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_RED_UPDATE_CHANNEL       ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_GREEN_UPDATE_CHANNEL     ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_BLUE_UPDATE_CHANNEL      ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_INTENSITY_UPDATE_CHANNEL ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_RED_UPDATE_CHANNEL       ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_GREEN_UPDATE_CHANNEL     ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_BLUE_UPDATE_CHANNEL      ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_INTENSITY_UPDATE_CHANNEL ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_RED_UPDATE_CHANNEL       ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_GREEN_UPDATE_CHANNEL     ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_BLUE_UPDATE_CHANNEL      ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_INTENSITY_UPDATE_CHANNEL ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_RED_UPDATE_CHANNEL       ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_GREEN_UPDATE_CHANNEL     ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_BLUE_UPDATE_CHANNEL      ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_INTENSITY_UPDATE_CHANNEL ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_RED_UPDATE_CHANNEL       ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_GREEN_UPDATE_CHANNEL     ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_BLUE_UPDATE_CHANNEL      ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_INTENSITY_UPDATE_CHANNEL ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_RED_UPDATE_CHANNEL       ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_GREEN_UPDATE_CHANNEL     ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_BLUE_UPDATE_CHANNEL      ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_INTENSITY_UPDATE_CHANNEL ),\
+      HID_LOGICAL_MIN   ( 0                                           ),\
+      HID_LOGICAL_MAX_N ( 255, 2                                      ),\
+      HID_REPORT_SIZE   ( 8                                           ),\
+      HID_REPORT_COUNT  ( 32                                          ),\
+      HID_FEATURE       ( HID_DATA | HID_VARIABLE | HID_ABSOLUTE      ),\
+    HID_COLLECTION_END ,\
+    /* Lamp Range Update Report */ \
+    HID_REPORT_ID       ( report_id + 4 ) \
+    HID_USAGE           ( HID_USAGE_LIGHTING_LAMP_RANGE_UPDATE_REPORT ),\
+    HID_COLLECTION      ( HID_COLLECTION_LOGICAL                      ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_LAMP_UPDATE_FLAGS        ),\
+      HID_LOGICAL_MIN   ( 0                                           ),\
+      HID_LOGICAL_MAX   ( 8                                           ),\
+      HID_REPORT_SIZE   ( 8                                           ),\
+      HID_REPORT_COUNT  ( 1                                           ),\
+      HID_FEATURE       ( HID_DATA | HID_VARIABLE | HID_ABSOLUTE      ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_LAMP_ID_START            ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_LAMP_ID_END              ),\
+      HID_LOGICAL_MIN   ( 0                                           ),\
+      HID_LOGICAL_MAX_N ( 65535, 3                                    ),\
+      HID_REPORT_SIZE   ( 16                                          ),\
+      HID_REPORT_COUNT  ( 2                                           ),\
+      HID_FEATURE       ( HID_DATA | HID_VARIABLE | HID_ABSOLUTE      ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_RED_UPDATE_CHANNEL       ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_GREEN_UPDATE_CHANNEL     ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_BLUE_UPDATE_CHANNEL      ),\
+      HID_USAGE         ( HID_USAGE_LIGHTING_INTENSITY_UPDATE_CHANNEL ),\
+      HID_LOGICAL_MIN   ( 0                                           ),\
+      HID_LOGICAL_MAX_N ( 255, 2                                      ),\
+      HID_REPORT_SIZE   ( 8                                           ),\
+      HID_REPORT_COUNT  ( 4                                           ),\
+      HID_FEATURE       ( HID_DATA | HID_VARIABLE | HID_ABSOLUTE      ),\
+    HID_COLLECTION_END ,\
+    /* Lamp Array Control Report */ \
+    HID_REPORT_ID      ( report_id + 5                                ) \
+    HID_USAGE          ( HID_USAGE_LIGHTING_LAMP_ARRAY_CONTROL_REPORT ),\
+    HID_COLLECTION     ( HID_COLLECTION_LOGICAL                       ),\
+      HID_USAGE        ( HID_USAGE_LIGHTING_AUTONOMOUS_MODE     ),\
+      HID_LOGICAL_MIN  ( 0                                      ),\
+      HID_LOGICAL_MAX  ( 1                                      ),\
+      HID_REPORT_SIZE  ( 8                                      ),\
+      HID_REPORT_COUNT ( 1                                      ),\
+      HID_FEATURE      ( HID_DATA | HID_VARIABLE | HID_ABSOLUTE ),\
+    HID_COLLECTION_END ,\
+  HID_COLLECTION_END \
+
 //--------------------------------------------------------------------+
 // Internal Class Driver API
 //--------------------------------------------------------------------+
@@ -475,4 +628,4 @@ bool     hidd_xfer_cb         (uint8_t rhport, uint8_t ep_addr, xfer_result_t ev
  }
 #endif
 
-#endif /* _TUSB_HID_DEVICE_H_ */
+#endif
diff --git a/src/class/hid/hid_host.c b/src/class/hid/hid_host.c
index 115a8a4df..7639a8fc6 100644
--- a/src/class/hid/hid_host.c
+++ b/src/class/hid/hid_host.c
@@ -657,7 +657,9 @@ uint8_t tuh_hid_parse_report_descriptor(tuh_hid_report_info_t* report_info_arr,
     uint8_t const data8 = desc_report[0];
 
     TU_LOG(3, "tag = %d, type = %d, size = %d, data = ", tag, type, size);
-    for (uint32_t i = 0; i < size; i++) TU_LOG(3, "%02X ", desc_report[i]);
+    for (uint32_t i = 0; i < size; i++) {
+      TU_LOG(3, "%02X ", desc_report[i]);
+    }
     TU_LOG(3, "\r\n");
 
     switch (type) {
diff --git a/src/class/msc/msc_device.c b/src/class/msc/msc_device.c
index 588fcaaca..447560b4d 100644
--- a/src/class/msc/msc_device.c
+++ b/src/class/msc/msc_device.c
@@ -689,6 +689,24 @@ static int32_t proc_builtin_scsi(uint8_t lun, uint8_t const scsi_cmd[16], uint8_
       }
     break;
 
+    case SCSI_CMD_PREVENT_ALLOW_MEDIUM_REMOVAL:
+      resplen = 0;
+
+      if (tud_msc_prevent_allow_medium_removal_cb)
+      {
+         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
+          resplen = - 1;
+
+          // set default sense if not set by callback
+          if ( p_msc->sense_key == 0 ) set_sense_medium_not_present(lun);
+        }
+      }
+    break;
+
+
     case SCSI_CMD_READ_CAPACITY_10:
     {
       uint32_t block_count;
diff --git a/src/class/msc/msc_device.h b/src/class/msc/msc_device.h
index 4247a40bd..29acd280a 100644
--- a/src/class/msc/msc_device.h
+++ b/src/class/msc/msc_device.h
@@ -131,6 +131,9 @@ TU_ATTR_WEAK uint8_t tud_msc_get_maxlun_cb(void);
 // - Start = 1 : active mode, if load_eject = 1 : load disk storage
 TU_ATTR_WEAK bool tud_msc_start_stop_cb(uint8_t lun, uint8_t power_condition, bool start, bool load_eject);
 
+//Invoked when we receive the Prevent / Allow Medium Removal command
+TU_ATTR_WEAK bool tud_msc_prevent_allow_medium_removal_cb(uint8_t lun, uint8_t prohibit_removal, uint8_t control);
+
 // Invoked when received REQUEST_SENSE
 TU_ATTR_WEAK int32_t tud_msc_request_sense_cb(uint8_t lun, void* buffer, uint16_t bufsize);
 
diff --git a/src/class/net/ncm.h b/src/class/net/ncm.h
index 96ba11fbc..1b987fca0 100644
--- a/src/class/net/ncm.h
+++ b/src/class/net/ncm.h
@@ -2,6 +2,7 @@
  * The MIT License (MIT)
  *
  * Copyright (c) 2021, Ha Thach (tinyusb.org)
+ * Copyright (c) 2024, Hardy Griech
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -24,22 +25,58 @@
  * This file is part of the TinyUSB stack.
  */
 
-
 #ifndef _TUSB_NCM_H_
 #define _TUSB_NCM_H_
 
 #include "common/tusb_common.h"
 
-#ifdef __cplusplus
- extern "C" {
+// NTB buffers size for reception side, must be >> MTU to avoid TCP retransmission (driver issue ?)
+// Linux use 2048 as minimal size
+#ifndef CFG_TUD_NCM_OUT_NTB_MAX_SIZE
+  #define CFG_TUD_NCM_OUT_NTB_MAX_SIZE 3200
 #endif
 
-// Table 4.3 Data Class Interface Protocol Codes
-typedef enum
-{
-  NCM_DATA_PROTOCOL_NETWORK_TRANSFER_BLOCK = 0x01
-} ncm_data_interface_protocol_code_t;
+// NTB buffers size for reception side, must be > MTU
+// Linux use 2048 as minimal size
+#ifndef CFG_TUD_NCM_IN_NTB_MAX_SIZE
+  #define CFG_TUD_NCM_IN_NTB_MAX_SIZE 3200
+#endif
+
+// Number of NTB buffers for reception side
+// Depending on the configuration, this parameter could be increased with the cost of additional RAM requirements
+// On Full-Speed (RP2040) :
+//    1  - good performance
+//    2  - up to 30% more performance with iperf with small packets
+//    >2 - no performance gain
+// On High-Speed (STM32F7) :
+//    No performance gain
+#ifndef CFG_TUD_NCM_OUT_NTB_N
+  #define CFG_TUD_NCM_OUT_NTB_N 1
+#endif
 
+// Number of NTB buffers for transmission side
+// Depending on the configuration, this parameter could be increased with the cost of additional RAM requirements
+// On Full-Speed (RP2040) :
+//    1 - good performance but SystemView shows lost events (on load test)
+//    2 - up to 50% more performance with iperf with small packets, "tud_network_can_xmit: request blocked"
+//        happens from time to time with SystemView
+//    3 - "tud_network_can_xmit: request blocked" never happens
+//    >3 - no performance gain
+// On High-Speed (STM32F7) :
+//    No performance gain
+#ifndef CFG_TUD_NCM_IN_NTB_N
+  #define CFG_TUD_NCM_IN_NTB_N 1
+#endif
+
+// How many datagrams it is allowed to put into an NTB for transmission side
+#ifndef CFG_TUD_NCM_IN_MAX_DATAGRAMS_PER_NTB
+  #define CFG_TUD_NCM_IN_MAX_DATAGRAMS_PER_NTB 8
+#endif
+
+// This tells the host how many datagrams it is allowed to put into an NTB
+#ifndef CFG_TUD_NCM_OUT_MAX_DATAGRAMS_PER_NTB
+  #define CFG_TUD_NCM_OUT_MAX_DATAGRAMS_PER_NTB 6
+#endif
 
 // Table 6.2 Class-Specific Request Codes for Network Control Model subclass
 typedef enum
@@ -62,8 +99,65 @@ typedef enum
   NCM_SET_CRC_MODE                                 = 0x8A,
 } ncm_request_code_t;
 
-#ifdef __cplusplus
- }
-#endif
+#define NTH16_SIGNATURE 0x484D434E
+#define NDP16_SIGNATURE_NCM0 0x304D434E
+#define NDP16_SIGNATURE_NCM1 0x314D434E
+
+typedef struct TU_ATTR_PACKED {
+  uint16_t wLength;
+  uint16_t bmNtbFormatsSupported;
+  uint32_t dwNtbInMaxSize;
+  uint16_t wNdbInDivisor;
+  uint16_t wNdbInPayloadRemainder;
+  uint16_t wNdbInAlignment;
+  uint16_t wReserved;
+  uint32_t dwNtbOutMaxSize;
+  uint16_t wNdbOutDivisor;
+  uint16_t wNdbOutPayloadRemainder;
+  uint16_t wNdbOutAlignment;
+  uint16_t wNtbOutMaxDatagrams;
+} ntb_parameters_t;
+
+typedef struct TU_ATTR_PACKED {
+  uint32_t dwSignature;
+  uint16_t wHeaderLength;
+  uint16_t wSequence;
+  uint16_t wBlockLength;
+  uint16_t wNdpIndex;
+} nth16_t;
+
+typedef struct TU_ATTR_PACKED {
+  uint16_t wDatagramIndex;
+  uint16_t wDatagramLength;
+} ndp16_datagram_t;
+
+typedef struct TU_ATTR_PACKED {
+  uint32_t dwSignature;
+  uint16_t wLength;
+  uint16_t wNextNdpIndex;
+  //ndp16_datagram_t datagram[];
+} ndp16_t;
+
+typedef union TU_ATTR_PACKED {
+  struct {
+    nth16_t nth;
+    ndp16_t ndp;
+    ndp16_datagram_t ndp_datagram[CFG_TUD_NCM_IN_MAX_DATAGRAMS_PER_NTB + 1];
+  };
+  uint8_t data[CFG_TUD_NCM_IN_NTB_MAX_SIZE];
+} xmit_ntb_t;
+
+typedef union TU_ATTR_PACKED {
+  struct {
+    nth16_t nth;
+    // only the header is at a guaranteed position
+  };
+  uint8_t data[CFG_TUD_NCM_OUT_NTB_MAX_SIZE];
+} recv_ntb_t;
+
+struct ncm_notify_t {
+  tusb_control_request_t header;
+  uint32_t downlink, uplink;
+};
 
 #endif
diff --git a/src/class/net/ncm_device.c b/src/class/net/ncm_device.c
index f84bd9f73..90d747185 100644
--- a/src/class/net/ncm_device.c
+++ b/src/class/net/ncm_device.c
@@ -1,9 +1,10 @@
 /*
  * The MIT License (MIT)
  *
+ * Copyright (c) 2019 Ha Thach (tinyusb.org)
+ * Copyright (c) 2024 Hardy Griech
  * Copyright (c) 2020 Jacob Berg Potter
  * Copyright (c) 2020 Peter Lawrence
- * Copyright (c) 2019 Ha Thach (tinyusb.org)
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -26,12 +27,37 @@
  * This file is part of the TinyUSB stack.
  */
 
+/**
+ * Small Glossary (from the spec)
+ * --------------
+ * Datagram - A collection of bytes forming a single item of information, passed as a unit from source to destination.
+ * NCM      - Network Control Model
+ * NDP      - NCM Datagram Pointer: NTB structure that delineates Datagrams (typically Ethernet frames) within an NTB
+ * NTB      - NCM Transfer Block: a data structure for efficient USB encapsulation of one or more datagrams
+ *            Each NTB is designed to be a single USB transfer
+ * NTH      - NTB Header: a data structure at the front of each NTB, which provides the information needed to validate
+ *            the NTB and begin decoding
+ *
+ * Some explanations
+ * -----------------
+ * - rhport        is the USB port of the device, in most cases "0"
+ * - itf_data_alt  if != 0 -> data xmit/recv are allowed (see spec)
+ * - ep_in         IN endpoints take data from the device intended to go in to the host (the device transmits)
+ * - ep_out        OUT endpoints send data out of the host to the device (the device receives)
+ */
+
 #include "tusb_option.h"
 
-#if ( CFG_TUD_ENABLED && CFG_TUD_NCM )
+#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"
+
+#include "ncm.h"
 #include "net_device.h"
 
 // Level where CFG_TUSB_DEBUG must be at least for this driver is logged
@@ -41,482 +67,829 @@
 
 #define TU_LOG_DRV(...)   TU_LOG(CFG_TUD_NCM_LOG_LEVEL, __VA_ARGS__)
 
-//--------------------------------------------------------------------+
-// MACRO CONSTANT TYPEDEF
-//--------------------------------------------------------------------+
+// Alignment must be 4
+#define TUD_NCM_ALIGNMENT   4
+// calculate alignment of xmit datagrams within an NTB
+#define XMIT_ALIGN_OFFSET(x) ((TUD_NCM_ALIGNMENT - ((x) & (TUD_NCM_ALIGNMENT - 1))) & (TUD_NCM_ALIGNMENT - 1))
 
-#define NTH16_SIGNATURE      0x484D434E
-#define NDP16_SIGNATURE_NCM0 0x304D434E
-#define NDP16_SIGNATURE_NCM1 0x314D434E
+//-----------------------------------------------------------------------------
+//
+// Module global things
+//
+#define XMIT_NTB_N CFG_TUD_NCM_IN_NTB_N
+#define RECV_NTB_N CFG_TUD_NCM_OUT_NTB_N
 
-typedef struct TU_ATTR_PACKED
-{
-  uint16_t wLength;
-  uint16_t bmNtbFormatsSupported;
-  uint32_t dwNtbInMaxSize;
-  uint16_t wNdbInDivisor;
-  uint16_t wNdbInPayloadRemainder;
-  uint16_t wNdbInAlignment;
-  uint16_t wReserved;
-  uint32_t dwNtbOutMaxSize;
-  uint16_t wNdbOutDivisor;
-  uint16_t wNdbOutPayloadRemainder;
-  uint16_t wNdbOutAlignment;
-  uint16_t wNtbOutMaxDatagrams;
-} ntb_parameters_t;
+typedef struct {
+  // general
+  uint8_t ep_in;        // endpoint for outgoing datagrams (naming is a little bit confusing)
+  uint8_t ep_out;       // endpoint for incoming datagrams (naming is a little bit confusing)
+  uint8_t ep_notif;     // endpoint for notifications
+  uint8_t itf_num;      // interface number
+  uint8_t itf_data_alt; // ==0 -> no endpoints, i.e. no network traffic, ==1 -> normal operation with two endpoints (spec, chapter 5.3)
+  uint8_t rhport;       // storage of \a rhport because some callbacks are done without it
 
-typedef struct TU_ATTR_PACKED
-{
-  uint32_t dwSignature;
-  uint16_t wHeaderLength;
-  uint16_t wSequence;
-  uint16_t wBlockLength;
-  uint16_t wNdpIndex;
-} nth16_t;
+  // recv handling
+  CFG_TUSB_MEM_ALIGN recv_ntb_t recv_ntb[RECV_NTB_N];   // actual recv NTBs
+  recv_ntb_t *recv_free_ntb[RECV_NTB_N];                // free list of recv NTBs
+  recv_ntb_t *recv_ready_ntb[RECV_NTB_N];               // NTBs waiting for transmission to glue logic
+  recv_ntb_t *recv_tinyusb_ntb;                         // buffer for the running transfer TinyUSB -> driver
+  recv_ntb_t *recv_glue_ntb;                            // buffer for the running transfer driver -> glue logic
+  uint16_t recv_glue_ntb_datagram_ndx;                  // index into \a recv_glue_ntb_datagram
 
-typedef struct TU_ATTR_PACKED
-{
-  uint16_t wDatagramIndex;
-  uint16_t wDatagramLength;
-} ndp16_datagram_t;
+  // xmit handling
+  CFG_TUSB_MEM_ALIGN xmit_ntb_t xmit_ntb[XMIT_NTB_N];   // actual xmit NTBs
+  xmit_ntb_t *xmit_free_ntb[XMIT_NTB_N];                // free list of xmit NTBs
+  xmit_ntb_t *xmit_ready_ntb[XMIT_NTB_N];               // NTBs waiting for transmission to TinyUSB
+  xmit_ntb_t *xmit_tinyusb_ntb;                         // buffer for the running transfer driver -> TinyUSB
+  xmit_ntb_t *xmit_glue_ntb;                            // buffer for the running transfer glue logic -> driver
+  uint16_t xmit_sequence;                               // NTB sequence counter
+  uint16_t xmit_glue_ntb_datagram_ndx;                  // index into \a xmit_glue_ntb_datagram
 
-typedef struct TU_ATTR_PACKED
-{
-  uint32_t dwSignature;
-  uint16_t wLength;
-  uint16_t wNextNdpIndex;
-  ndp16_datagram_t datagram[];
-} ndp16_t;
+  // notification handling
+  enum {
+    NOTIFICATION_SPEED,
+    NOTIFICATION_CONNECTED,
+    NOTIFICATION_DONE
+  } notification_xmit_state;            // state of notification transmission
+  bool notification_xmit_is_running;    // notification is currently transmitted
+} ncm_interface_t;
 
-typedef union TU_ATTR_PACKED {
-  struct {
-    nth16_t nth;
-    ndp16_t ndp;
-  };
-  uint8_t data[CFG_TUD_NCM_IN_NTB_MAX_SIZE];
-} transmit_ntb_t;
+CFG_TUD_MEM_SECTION CFG_TUD_MEM_ALIGN tu_static ncm_interface_t ncm_interface;
 
-struct ecm_notify_struct
-{
-  tusb_control_request_t header;
-  uint32_t downlink, uplink;
+/**
+ * This is the NTB parameter structure
+ *
+ * \attention
+ *     We are lucky, that byte order is correct
+ */
+CFG_TUD_MEM_SECTION CFG_TUD_MEM_ALIGN tu_static const ntb_parameters_t ntb_parameters = {
+  .wLength                  = sizeof(ntb_parameters_t),
+  .bmNtbFormatsSupported    = 0x01,// 16-bit NTB supported
+  .dwNtbInMaxSize           = CFG_TUD_NCM_IN_NTB_MAX_SIZE,
+  .wNdbInDivisor            = 1,
+  .wNdbInPayloadRemainder   = 0,
+  .wNdbInAlignment          = TUD_NCM_ALIGNMENT,
+  .wReserved                = 0,
+  .dwNtbOutMaxSize          = CFG_TUD_NCM_OUT_NTB_MAX_SIZE,
+  .wNdbOutDivisor           = 1,
+  .wNdbOutPayloadRemainder  = 0,
+  .wNdbOutAlignment         = TUD_NCM_ALIGNMENT,
+  .wNtbOutMaxDatagrams      = CFG_TUD_NCM_OUT_MAX_DATAGRAMS_PER_NTB,
 };
 
-typedef struct
-{
-  uint8_t itf_num;      // Index number of Management Interface, +1 for Data Interface
-  uint8_t itf_data_alt; // Alternate setting of Data Interface. 0 : inactive, 1 : active
+// Some confusing remarks about wNtbOutMaxDatagrams...
+//      ==1 -> SystemView packets/s goes up to 2000 and events are lost during startup
+//      ==0 -> SystemView runs fine, iperf shows in wireshark a lot of error
+//      ==6 -> SystemView runs fine, iperf also
+//      >6  -> iperf starts to show errors
+//      -> 6 seems to be the best value.  Why?  Don't know, perhaps only on my system?
+//
+//      iperf:    for MSS in 100 200 400 800 1200 1450 1500; do iperf -c 192.168.14.1 -e -i 1 -M $MSS -l 8192 -P 1; sleep 2; done
+//      sysview:  SYSTICKS_PER_SEC=35000, IDLE_US=1000, PRINT_MOD=1000
+//
 
-  uint8_t ep_notif;
-  uint8_t ep_in;
-  uint8_t ep_out;
+//-----------------------------------------------------------------------------
+//
+// everything about notifications
+//
+tu_static struct ncm_notify_t ncm_notify_connected = {
+    .header = {
+        .bmRequestType_bit = {
+            .recipient = TUSB_REQ_RCPT_INTERFACE,
+            .type = TUSB_REQ_TYPE_CLASS,
+            .direction = TUSB_DIR_IN},
+        .bRequest = CDC_NOTIF_NETWORK_CONNECTION,
+        .wValue = 1 /* Connected */,
+        .wLength = 0,
+    },
+};
 
-  const ndp16_t *ndp;
-  uint8_t num_datagrams, current_datagram_index;
+tu_static struct ncm_notify_t ncm_notify_speed_change = {
+    .header = {
+        .bmRequestType_bit = {
+            .recipient = TUSB_REQ_RCPT_INTERFACE,
+            .type = TUSB_REQ_TYPE_CLASS,
+            .direction = TUSB_DIR_IN},
+        .bRequest = CDC_NOTIF_CONNECTION_SPEED_CHANGE,
+        .wLength = 8,
+    },
+    .downlink = TUD_OPT_HIGH_SPEED ? 480000000 : 12000000,
+    .uplink = TUD_OPT_HIGH_SPEED ? 480000000 : 12000000,
+};
 
-  enum {
-    REPORT_SPEED,
-    REPORT_CONNECTED,
-    REPORT_DONE
-  } report_state;
-  bool report_pending;
+/**
+ * Transmit next notification to the host (if appropriate).
+ * Notifications are transferred to the host once during connection setup.
+ */
+static void notification_xmit(uint8_t rhport, bool force_next) {
+  TU_LOG_DRV("notification_xmit(%d, %d) - %d %d\n", force_next, rhport, ncm_interface.notification_xmit_state, ncm_interface.notification_xmit_is_running);
 
-  uint8_t  current_ntb;           // Index in transmit_ntb[] that is currently being filled with datagrams
-  uint8_t  datagram_count;        // Number of datagrams in transmit_ntb[current_ntb]
-  uint16_t next_datagram_offset;  // Offset in transmit_ntb[current_ntb].data to place the next datagram
-  uint16_t ntb_in_size;           // Maximum size of transmitted (IN to host) NTBs; initially CFG_TUD_NCM_IN_NTB_MAX_SIZE
-  uint8_t  max_datagrams_per_ntb; // Maximum number of datagrams per NTB; initially CFG_TUD_NCM_MAX_DATAGRAMS_PER_NTB
+  if (!force_next && ncm_interface.notification_xmit_is_running) {
+    return;
+  }
 
-  uint16_t nth_sequence;          // Sequence number counter for transmitted NTBs
+  if (ncm_interface.notification_xmit_state == NOTIFICATION_SPEED) {
+    TU_LOG_DRV("  NOTIFICATION_SPEED\n");
+    ncm_notify_speed_change.header.wIndex = ncm_interface.itf_num;
+    usbd_edpt_xfer(rhport, ncm_interface.ep_notif, (uint8_t *) &ncm_notify_speed_change, sizeof(ncm_notify_speed_change));
+    ncm_interface.notification_xmit_state = NOTIFICATION_CONNECTED;
+    ncm_interface.notification_xmit_is_running = true;
+  } else if (ncm_interface.notification_xmit_state == NOTIFICATION_CONNECTED) {
+    TU_LOG_DRV("  NOTIFICATION_CONNECTED\n");
+    ncm_notify_connected.header.wIndex = ncm_interface.itf_num;
+    usbd_edpt_xfer(rhport, ncm_interface.ep_notif, (uint8_t *) &ncm_notify_connected, sizeof(ncm_notify_connected));
+    ncm_interface.notification_xmit_state = NOTIFICATION_DONE;
+    ncm_interface.notification_xmit_is_running = true;
+  } else {
+    TU_LOG_DRV("  NOTIFICATION_FINISHED\n");
+  }
+} // notification_xmit
 
-  bool transferring;
+//-----------------------------------------------------------------------------
+//
+// everything about packet transmission (driver -> TinyUSB)
+//
 
-} ncm_interface_t;
+/**
+ * Put NTB into the transmitter free list.
+ */
+static void xmit_put_ntb_into_free_list(xmit_ntb_t *free_ntb) {
+  TU_LOG_DRV("xmit_put_ntb_into_free_list() - %p\n", ncm_interface.xmit_tinyusb_ntb);
 
-//--------------------------------------------------------------------+
-// INTERNAL OBJECT & FUNCTION DECLARATION
-//--------------------------------------------------------------------+
+  if (free_ntb == NULL) { // can happen due to ZLPs
+    return;
+  }
 
-CFG_TUD_MEM_SECTION CFG_TUSB_MEM_ALIGN tu_static const ntb_parameters_t ntb_parameters = {
-    .wLength                 = sizeof(ntb_parameters_t),
-    .bmNtbFormatsSupported   = 0x01,
-    .dwNtbInMaxSize          = CFG_TUD_NCM_IN_NTB_MAX_SIZE,
-    .wNdbInDivisor           = 4,
-    .wNdbInPayloadRemainder  = 0,
-    .wNdbInAlignment         = CFG_TUD_NCM_ALIGNMENT,
-    .wReserved               = 0,
-    .dwNtbOutMaxSize         = CFG_TUD_NCM_OUT_NTB_MAX_SIZE,
-    .wNdbOutDivisor          = 4,
-    .wNdbOutPayloadRemainder = 0,
-    .wNdbOutAlignment        = CFG_TUD_NCM_ALIGNMENT,
-    .wNtbOutMaxDatagrams     = 0
-};
+  for (int i = 0; i < XMIT_NTB_N; ++i) {
+    if (ncm_interface.xmit_free_ntb[i] == NULL) {
+      ncm_interface.xmit_free_ntb[i] = free_ntb;
+      return;
+    }
+  }
+  TU_LOG_DRV("(EE) xmit_put_ntb_into_free_list - no entry in free list\n");// this should not happen
+} // xmit_put_ntb_into_free_list
 
-CFG_TUD_MEM_SECTION CFG_TUSB_MEM_ALIGN tu_static transmit_ntb_t transmit_ntb[2];
+/**
+ * Get an NTB from the free list
+ */
+static xmit_ntb_t *xmit_get_free_ntb(void) {
+  TU_LOG_DRV("xmit_get_free_ntb()\n");
 
-CFG_TUD_MEM_SECTION CFG_TUSB_MEM_ALIGN tu_static uint8_t receive_ntb[CFG_TUD_NCM_OUT_NTB_MAX_SIZE];
+  for (int i = 0; i < XMIT_NTB_N; ++i) {
+    if (ncm_interface.xmit_free_ntb[i] != NULL) {
+      xmit_ntb_t *free = ncm_interface.xmit_free_ntb[i];
+      ncm_interface.xmit_free_ntb[i] = NULL;
+      return free;
+    }
+  }
+  return NULL;
+} // xmit_get_free_ntb
 
-tu_static ncm_interface_t ncm_interface;
+/**
+ * Put a filled NTB into the ready list
+ */
+static void xmit_put_ntb_into_ready_list(xmit_ntb_t *ready_ntb) {
+  TU_LOG_DRV("xmit_put_ntb_into_ready_list(%p) %d\n", ready_ntb, ready_ntb->nth.wBlockLength);
 
-/*
- * Set up the NTB state in ncm_interface to be ready to add datagrams.
+  for (int i = 0; i < XMIT_NTB_N; ++i) {
+    if (ncm_interface.xmit_ready_ntb[i] == NULL) {
+      ncm_interface.xmit_ready_ntb[i] = ready_ntb;
+      return;
+    }
+  }
+  TU_LOG_DRV("(EE) xmit_put_ntb_into_ready_list: ready list full\n");// this should not happen
+} // xmit_put_ntb_into_ready_list
+
+/**
+ * Get the next NTB from the ready list (and remove it from the list).
+ * If the ready list is empty, return NULL.
  */
-static void ncm_prepare_for_tx(void) {
-  ncm_interface.datagram_count = 0;
-  // datagrams start after all the headers
-  ncm_interface.next_datagram_offset = sizeof(nth16_t) + sizeof(ndp16_t)
-      + ((CFG_TUD_NCM_MAX_DATAGRAMS_PER_NTB + 1) * sizeof(ndp16_datagram_t));
-}
+static xmit_ntb_t *xmit_get_next_ready_ntb(void) {
+  xmit_ntb_t *r = NULL;
 
-/*
- * If not already transmitting, start sending the current NTB to the host and swap buffers
- * to start filling the other one with datagrams.
+  r = ncm_interface.xmit_ready_ntb[0];
+  memmove(ncm_interface.xmit_ready_ntb + 0, ncm_interface.xmit_ready_ntb + 1, sizeof(ncm_interface.xmit_ready_ntb) - sizeof(ncm_interface.xmit_ready_ntb[0]));
+  ncm_interface.xmit_ready_ntb[XMIT_NTB_N - 1] = NULL;
+
+  TU_LOG_DRV("recv_get_next_ready_ntb: %p\n", r);
+  return r;
+} // xmit_get_next_ready_ntb
+
+/**
+ * Transmit a ZLP if required
+ *
+ * \note
+ *    Insertion of the ZLPs is a little bit different then described in the spec.
+ *    But the below implementation actually works.  Don't know if this is a spec
+ *    or TinyUSB issue.
+ *
+ * \pre
+ *    This must be called from netd_xfer_cb() so that ep_in is ready
  */
-static void ncm_start_tx(void) {
-  if (ncm_interface.transferring) {
+static bool xmit_insert_required_zlp(uint8_t rhport, uint32_t xferred_bytes) {
+  TU_LOG_DRV("xmit_insert_required_zlp(%d,%ld)\n", rhport, xferred_bytes);
+
+  if (xferred_bytes == 0 || xferred_bytes % CFG_TUD_NET_ENDPOINT_SIZE != 0) {
+    return false;
+  }
+
+  TU_ASSERT(ncm_interface.itf_data_alt == 1, false);
+  TU_ASSERT(!usbd_edpt_busy(rhport, ncm_interface.ep_in), false);
+
+  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);
+
+  return true;
+} // xmit_insert_required_zlp
+
+/**
+ * Start transmission if it there is a waiting packet and if can be done from interface side.
+ */
+static void xmit_start_if_possible(uint8_t rhport) {
+  TU_LOG_DRV("xmit_start_if_possible()\n");
+
+  if (ncm_interface.xmit_tinyusb_ntb != NULL) {
+    TU_LOG_DRV("  !xmit_start_if_possible 1\n");
+    return;
+  }
+  if (ncm_interface.itf_data_alt != 1) {
+    TU_LOG_DRV("(EE) !xmit_start_if_possible 2\n");
+    return;
+  }
+  if (usbd_edpt_busy(rhport, ncm_interface.ep_in)) {
+    TU_LOG_DRV("  !xmit_start_if_possible 3\n");
     return;
   }
 
-  transmit_ntb_t *ntb = &transmit_ntb[ncm_interface.current_ntb];
-  size_t ntb_length = ncm_interface.next_datagram_offset;
+  ncm_interface.xmit_tinyusb_ntb = xmit_get_next_ready_ntb();
+  if (ncm_interface.xmit_tinyusb_ntb == NULL) {
+    if (ncm_interface.xmit_glue_ntb == NULL || ncm_interface.xmit_glue_ntb_datagram_ndx == 0) {
+      // -> really nothing is waiting
+      return;
+    }
+    ncm_interface.xmit_tinyusb_ntb = ncm_interface.xmit_glue_ntb;
+    ncm_interface.xmit_glue_ntb = NULL;
+  }
+
+  #if CFG_TUD_NCM_LOG_LEVEL >= 3
+  {
+    uint16_t len = ncm_interface.xmit_tinyusb_ntb->nth.wBlockLength;
+    TU_LOG_BUF(3, ncm_interface.xmit_tinyusb_ntb->data[i], len);
+  }
+  #endif
+
+  if (ncm_interface.xmit_glue_ntb_datagram_ndx != 1) {
+    TU_LOG_DRV(">> %d %d\n", ncm_interface.xmit_tinyusb_ntb->nth.wBlockLength, ncm_interface.xmit_glue_ntb_datagram_ndx);
+  }
+
+  // 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);
+} // xmit_start_if_possible
+
+/**
+ * check if a new datagram fits into the current NTB
+ */
+static bool xmit_requested_datagram_fits_into_current_ntb(uint16_t datagram_size) {
+  TU_LOG_DRV("xmit_requested_datagram_fits_into_current_ntb(%d) - %p %p\n", datagram_size, ncm_interface.xmit_tinyusb_ntb, ncm_interface.xmit_glue_ntb);
+
+  if (ncm_interface.xmit_glue_ntb == NULL) {
+    return false;
+  }
+  if (ncm_interface.xmit_glue_ntb_datagram_ndx >= CFG_TUD_NCM_IN_MAX_DATAGRAMS_PER_NTB) {
+    return false;
+  }
+  if (ncm_interface.xmit_glue_ntb->nth.wBlockLength + datagram_size + XMIT_ALIGN_OFFSET(datagram_size) > CFG_TUD_NCM_OUT_NTB_MAX_SIZE) {
+    return false;
+  }
+  return true;
+} // xmit_requested_datagram_fits_into_current_ntb
+
+/**
+ * Setup an NTB for the glue logic
+ */
+static bool xmit_setup_next_glue_ntb(void) {
+  TU_LOG_DRV("xmit_setup_next_glue_ntb - %p\n", ncm_interface.xmit_glue_ntb);
+
+  if (ncm_interface.xmit_glue_ntb != NULL) {
+    // put NTB into waiting list (the new datagram did not fit in)
+    xmit_put_ntb_into_ready_list(ncm_interface.xmit_glue_ntb);
+  }
+
+  ncm_interface.xmit_glue_ntb = xmit_get_free_ntb();// get next buffer (if any)
+  if (ncm_interface.xmit_glue_ntb == NULL) {
+    TU_LOG_DRV("  xmit_setup_next_glue_ntb - nothing free\n");// should happen rarely
+    return false;
+  }
+
+  ncm_interface.xmit_glue_ntb_datagram_ndx = 0;
+
+  xmit_ntb_t *ntb = ncm_interface.xmit_glue_ntb;
 
   // Fill in NTB header
   ntb->nth.dwSignature = NTH16_SIGNATURE;
-  ntb->nth.wHeaderLength = sizeof(nth16_t);
-  ntb->nth.wSequence = ncm_interface.nth_sequence++;
-  ntb->nth.wBlockLength = ntb_length;
-  ntb->nth.wNdpIndex = sizeof(nth16_t);
+  ntb->nth.wHeaderLength = sizeof(ntb->nth);
+  ntb->nth.wSequence = ncm_interface.xmit_sequence++;
+  ntb->nth.wBlockLength = sizeof(ntb->nth) + sizeof(ntb->ndp) + sizeof(ntb->ndp_datagram);
+  ntb->nth.wNdpIndex = sizeof(ntb->nth);
 
   // Fill in NDP16 header and terminator
   ntb->ndp.dwSignature = NDP16_SIGNATURE_NCM0;
-  ntb->ndp.wLength = sizeof(ndp16_t) + (ncm_interface.datagram_count + 1) * sizeof(ndp16_datagram_t);
+  ntb->ndp.wLength = sizeof(ntb->ndp) + sizeof(ntb->ndp_datagram);
   ntb->ndp.wNextNdpIndex = 0;
-  ntb->ndp.datagram[ncm_interface.datagram_count].wDatagramIndex = 0;
-  ntb->ndp.datagram[ncm_interface.datagram_count].wDatagramLength = 0;
-
-  // Kick off an endpoint transfer
-  usbd_edpt_xfer(0, ncm_interface.ep_in, ntb->data, ntb_length);
-  ncm_interface.transferring = true;
 
-  // Swap to the other NTB and clear it out
-  ncm_interface.current_ntb = 1 - ncm_interface.current_ntb;
-  ncm_prepare_for_tx();
-}
+  memset(ntb->ndp_datagram, 0, sizeof(ntb->ndp_datagram));
+  return true;
+} // xmit_setup_next_glue_ntb
 
-tu_static struct ecm_notify_struct ncm_notify_connected =
-{
-    .header = {
-        .bmRequestType_bit = {
-          .recipient = TUSB_REQ_RCPT_INTERFACE,
-          .type      = TUSB_REQ_TYPE_CLASS,
-          .direction = TUSB_DIR_IN
-        },
-        .bRequest      = CDC_NOTIF_NETWORK_CONNECTION,
-        .wValue        = 1 /* Connected */,
-        .wLength       = 0,
-    },
-};
+//-----------------------------------------------------------------------------
+//
+// all the recv_*() stuff (TinyUSB -> driver -> glue logic)
+//
 
-tu_static struct ecm_notify_struct ncm_notify_speed_change =
-{
-    .header = {
-        .bmRequestType_bit = {
-          .recipient = TUSB_REQ_RCPT_INTERFACE,
-          .type      = TUSB_REQ_TYPE_CLASS,
-          .direction = TUSB_DIR_IN
-        },
-        .bRequest = CDC_NOTIF_CONNECTION_SPEED_CHANGE,
-        .wLength = 8,
-    },
-    .downlink = 10000000,
-    .uplink = 10000000,
-};
+/**
+ * Return pointer to an available receive buffer or NULL.
+ * Returned buffer (if any) has the size \a CFG_TUD_NCM_OUT_NTB_MAX_SIZE.
+ */
+static recv_ntb_t *recv_get_free_ntb(void) {
+  TU_LOG_DRV("recv_get_free_ntb()\n");
 
-void tud_network_recv_renew(void)
-{
-  if (!ncm_interface.num_datagrams)
-  {
-    usbd_edpt_xfer(0, ncm_interface.ep_out, receive_ntb, sizeof(receive_ntb));
-    return;
+  for (int i = 0; i < RECV_NTB_N; ++i) {
+    if (ncm_interface.recv_free_ntb[i] != NULL) {
+      recv_ntb_t *free = ncm_interface.recv_free_ntb[i];
+      ncm_interface.recv_free_ntb[i] = NULL;
+      return free;
+    }
   }
+  return NULL;
+} // recv_get_free_ntb
 
-  const ndp16_t *ndp = ncm_interface.ndp;
-  const int i = ncm_interface.current_datagram_index;
-  ncm_interface.current_datagram_index++;
-  ncm_interface.num_datagrams--;
+/**
+ * Get the next NTB from the ready list (and remove it from the list).
+ * If the ready list is empty, return NULL.
+ */
+static recv_ntb_t *recv_get_next_ready_ntb(void) {
+  recv_ntb_t *r = NULL;
 
-  tud_network_recv_cb(receive_ntb + ndp->datagram[i].wDatagramIndex, ndp->datagram[i].wDatagramLength);
-}
+  r = ncm_interface.recv_ready_ntb[0];
+  memmove(ncm_interface.recv_ready_ntb + 0, ncm_interface.recv_ready_ntb + 1, sizeof(ncm_interface.recv_ready_ntb) - sizeof(ncm_interface.recv_ready_ntb[0]));
+  ncm_interface.recv_ready_ntb[RECV_NTB_N - 1] = NULL;
 
-//--------------------------------------------------------------------+
-// USBD Driver API
-//--------------------------------------------------------------------+
+  TU_LOG_DRV("recv_get_next_ready_ntb: %p\n", r);
+  return r;
+} // recv_get_next_ready_ntb
 
-void netd_init(void)
-{
-  tu_memclr(&ncm_interface, sizeof(ncm_interface));
-  ncm_interface.ntb_in_size = CFG_TUD_NCM_IN_NTB_MAX_SIZE;
-  ncm_interface.max_datagrams_per_ntb = CFG_TUD_NCM_MAX_DATAGRAMS_PER_NTB;
-  ncm_prepare_for_tx();
-}
+/**
+ * Put NTB into the receiver free list.
+ */
+static void recv_put_ntb_into_free_list(recv_ntb_t *free_ntb) {
+  TU_LOG_DRV("recv_put_ntb_into_free_list(%p)\n", free_ntb);
 
-bool netd_deinit(void) {
-  return true;
-}
+  for (int i = 0; i < RECV_NTB_N; ++i) {
+    if (ncm_interface.recv_free_ntb[i] == NULL) {
+      ncm_interface.recv_free_ntb[i] = free_ntb;
+      return;
+    }
+  }
+  TU_LOG_DRV("(EE) recv_put_ntb_into_free_list - no entry in free list\n");// this should not happen
+} // recv_put_ntb_into_free_list
 
-void netd_reset(uint8_t rhport)
-{
-  (void) rhport;
+/**
+ * \a ready_ntb holds a validated NTB,
+ * put this buffer into the waiting list.
+ */
+static void recv_put_ntb_into_ready_list(recv_ntb_t *ready_ntb) {
+  TU_LOG_DRV("recv_put_ntb_into_ready_list(%p) %d\n", ready_ntb, ready_ntb->nth.wBlockLength);
 
-  netd_init();
-}
+  for (int i = 0; i < RECV_NTB_N; ++i) {
+    if (ncm_interface.recv_ready_ntb[i] == NULL) {
+      ncm_interface.recv_ready_ntb[i] = ready_ntb;
+      return;
+    }
+  }
+  TU_LOG_DRV("(EE) recv_put_ntb_into_ready_list: ready list full\n");// this should not happen
+} // recv_put_ntb_into_ready_list
 
-uint16_t netd_open(uint8_t rhport, tusb_desc_interface_t const * itf_desc, uint16_t max_len)
-{
-  // confirm interface hasn't already been allocated
-  TU_ASSERT(0 == ncm_interface.ep_notif, 0);
+/**
+ * If possible, start a new reception TinyUSB -> driver.
+ */
+static void recv_try_to_start_new_reception(uint8_t rhport) {
+  TU_LOG_DRV("recv_try_to_start_new_reception(%d)\n", rhport);
 
-  //------------- Management Interface -------------//
-  ncm_interface.itf_num = itf_desc->bInterfaceNumber;
+  if (ncm_interface.itf_data_alt != 1) {
+    return;
+  }
+  if (ncm_interface.recv_tinyusb_ntb != NULL) {
+    return;
+  }
+  if (usbd_edpt_busy(rhport, ncm_interface.ep_out)) {
+    return;
+  }
 
-  uint16_t drv_len = sizeof(tusb_desc_interface_t);
-  uint8_t const * p_desc = tu_desc_next( itf_desc );
+  ncm_interface.recv_tinyusb_ntb = recv_get_free_ntb();
+  if (ncm_interface.recv_tinyusb_ntb == NULL) {
+    return;
+  }
 
-  // Communication Functional 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);
+  // 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);
+  if (!r) {
+    recv_put_ntb_into_free_list(ncm_interface.recv_tinyusb_ntb);
+    ncm_interface.recv_tinyusb_ntb = NULL;
   }
+} // recv_try_to_start_new_reception
 
-  // notification endpoint (if any)
-  if ( TUSB_DESC_ENDPOINT == tu_desc_type(p_desc) )
-  {
-    TU_ASSERT( usbd_edpt_open(rhport, (tusb_desc_endpoint_t const *) p_desc), 0 );
+/**
+ * Validate incoming datagram.
+ * \return true if valid
+ *
+ * \note
+ *    \a ndp16->wNextNdpIndex != 0 is not supported
+ */
+static bool recv_validate_datagram(const recv_ntb_t *ntb, uint32_t len) {
+  const nth16_t *nth16 = &(ntb->nth);
 
-    ncm_interface.ep_notif = ((tusb_desc_endpoint_t const *) p_desc)->bEndpointAddress;
+  TU_LOG_DRV("recv_validate_datagram(%p, %d)\n", ntb, (int) len);
 
-    drv_len += tu_desc_len(p_desc);
-    p_desc   = tu_desc_next(p_desc);
+  // check header
+  if (nth16->wHeaderLength != sizeof(nth16_t)) {
+    TU_LOG_DRV("(EE) ill nth16 length: %d\n", nth16->wHeaderLength);
+    return false;
+  }
+  if (nth16->dwSignature != NTH16_SIGNATURE) {
+    TU_LOG_DRV("(EE) ill signature: 0x%08x\n", (unsigned) nth16->dwSignature);
+    return false;
+  }
+  if (len < sizeof(nth16_t) + sizeof(ndp16_t) + 2 * sizeof(ndp16_datagram_t)) {
+    TU_LOG_DRV("(EE) ill min len: %lu\n", len);
+    return false;
+  }
+  if (nth16->wBlockLength > len) {
+    TU_LOG_DRV("(EE) ill block length: %d > %lu\n", nth16->wBlockLength, len);
+    return false;
+  }
+  if (nth16->wBlockLength > CFG_TUD_NCM_OUT_NTB_MAX_SIZE) {
+    TU_LOG_DRV("(EE) ill block length2: %d > %d\n", nth16->wBlockLength, CFG_TUD_NCM_OUT_NTB_MAX_SIZE);
+    return false;
+  }
+  if (nth16->wNdpIndex < sizeof(nth16) || nth16->wNdpIndex > len - (sizeof(ndp16_t) + 2 * sizeof(ndp16_datagram_t))) {
+    TU_LOG_DRV("(EE) ill position of first ndp: %d (%lu)\n", nth16->wNdpIndex, len);
+    return false;
   }
 
-  //------------- Data Interface -------------//
-  // - CDC-NCM data interface has 2 alternate settings
-  //   - 0 : zero endpoints for inactive (default)
-  //   - 1 : IN & OUT endpoints for transfer of NTBs
-  TU_ASSERT(TUSB_DESC_INTERFACE == tu_desc_type(p_desc), 0);
+  // check (first) NDP(16)
+  const ndp16_t *ndp16 = (const ndp16_t *) (ntb->data + nth16->wNdpIndex);
 
-  do
-  {
-    tusb_desc_interface_t const * data_itf_desc = (tusb_desc_interface_t const *) p_desc;
-    TU_ASSERT(TUSB_CLASS_CDC_DATA == data_itf_desc->bInterfaceClass, 0);
+  if (ndp16->wLength < sizeof(ndp16_t) + 2 * sizeof(ndp16_datagram_t)) {
+    TU_LOG_DRV("(EE) ill ndp16 length: %d\n", ndp16->wLength);
+    return false;
+  }
+  if (ndp16->dwSignature != NDP16_SIGNATURE_NCM0 && ndp16->dwSignature != NDP16_SIGNATURE_NCM1) {
+    TU_LOG_DRV("(EE) ill signature: 0x%08x\n", (unsigned) ndp16->dwSignature);
+    return false;
+  }
+  if (ndp16->wNextNdpIndex != 0) {
+    TU_LOG_DRV("(EE) cannot handle wNextNdpIndex!=0 (%d)\n", ndp16->wNextNdpIndex);
+    return false;
+  }
 
-    drv_len += tu_desc_len(p_desc);
-    p_desc   = tu_desc_next(p_desc);
-  } while((TUSB_DESC_INTERFACE == tu_desc_type(p_desc)) && (drv_len <= max_len));
+  const ndp16_datagram_t *ndp16_datagram = (const ndp16_datagram_t *) (ntb->data + nth16->wNdpIndex + sizeof(ndp16_t));
+  int ndx = 0;
+  uint16_t max_ndx = (uint16_t) ((ndp16->wLength - sizeof(ndp16_t)) / sizeof(ndp16_datagram_t));
 
-  // Pair of endpoints
-  TU_ASSERT(TUSB_DESC_ENDPOINT == tu_desc_type(p_desc), 0);
+  if (max_ndx > 2) { // number of datagrams in NTB > 1
+    TU_LOG_DRV("<< %d (%d)\n", max_ndx - 1, ntb->nth.wBlockLength);
+  }
+  if (ndp16_datagram[max_ndx - 1].wDatagramIndex != 0 || ndp16_datagram[max_ndx - 1].wDatagramLength != 0) {
+    TU_LOG_DRV("  max_ndx != 0\n");
+    return false;
+  }
+  while (ndp16_datagram[ndx].wDatagramIndex != 0 && ndp16_datagram[ndx].wDatagramLength != 0) {
+    TU_LOG_DRV("  << %d %d\n", ndp16_datagram[ndx].wDatagramIndex, ndp16_datagram[ndx].wDatagramLength);
+    if (ndp16_datagram[ndx].wDatagramIndex > len) {
+      TU_LOG_DRV("(EE) ill start of datagram[%d]: %d (%lu)\n", ndx, ndp16_datagram[ndx].wDatagramIndex, len);
+      return false;
+    }
+    if (ndp16_datagram[ndx].wDatagramIndex + ndp16_datagram[ndx].wDatagramLength > len) {
+      TU_LOG_DRV("(EE) ill end of datagram[%d]: %d (%lu)\n", ndx, ndp16_datagram[ndx].wDatagramIndex + ndp16_datagram[ndx].wDatagramLength, len);
+      return false;
+    }
+    ++ndx;
+  }
 
-  TU_ASSERT(usbd_open_edpt_pair(rhport, p_desc, 2, TUSB_XFER_BULK, &ncm_interface.ep_out, &ncm_interface.ep_in) );
+  #if CFG_TUD_NCM_LOG_LEVEL >= 3
+  TU_LOG_BUF(3, ntb->data[i], len);
+  #endif
 
-  drv_len += 2*sizeof(tusb_desc_endpoint_t);
+  // -> ntb contains a valid packet structure
+  //    ok... I did not check for garbage within the datagram indices...
+  return true;
+} // recv_validate_datagram
 
-  return drv_len;
-}
+/**
+ * Transfer the next (pending) datagram to the glue logic and return receive buffer if empty.
+ */
+static void recv_transfer_datagram_to_glue_logic(void) {
+  TU_LOG_DRV("recv_transfer_datagram_to_glue_logic()\n");
 
-static void ncm_report(void)
-{
-  uint8_t const rhport = 0;
-  if (ncm_interface.report_state == REPORT_SPEED) {
-    ncm_notify_speed_change.header.wIndex = ncm_interface.itf_num;
-    usbd_edpt_xfer(rhport, ncm_interface.ep_notif, (uint8_t *) &ncm_notify_speed_change, sizeof(ncm_notify_speed_change));
-    ncm_interface.report_state = REPORT_CONNECTED;
-    ncm_interface.report_pending = true;
-  } else if (ncm_interface.report_state == REPORT_CONNECTED) {
-    ncm_notify_connected.header.wIndex = ncm_interface.itf_num;
-    usbd_edpt_xfer(rhport, ncm_interface.ep_notif, (uint8_t *) &ncm_notify_connected, sizeof(ncm_notify_connected));
-    ncm_interface.report_state = REPORT_DONE;
-    ncm_interface.report_pending = true;
+  if (ncm_interface.recv_glue_ntb == NULL) {
+    ncm_interface.recv_glue_ntb = recv_get_next_ready_ntb();
+    TU_LOG_DRV("  new buffer for glue logic: %p\n", ncm_interface.recv_glue_ntb);
+    ncm_interface.recv_glue_ntb_datagram_ndx = 0;
   }
-}
 
-TU_ATTR_WEAK void tud_network_link_state_cb(bool state)
-{
-  (void)state;
-}
+  if (ncm_interface.recv_glue_ntb != NULL) {
+    const ndp16_datagram_t *ndp16_datagram = (ndp16_datagram_t *) (ncm_interface.recv_glue_ntb->data + ncm_interface.recv_glue_ntb->nth.wNdpIndex + sizeof(ndp16_t));
 
-// Handle class control request
-// return false to stall control endpoint (e.g unsupported request)
-bool netd_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb_control_request_t const * request)
-{
-  if ( stage != CONTROL_STAGE_SETUP ) return true;
+    if (ndp16_datagram[ncm_interface.recv_glue_ntb_datagram_ndx].wDatagramIndex == 0) {
+      TU_LOG_DRV("(EE) SOMETHING WENT WRONG 1\n");
+    } else if (ndp16_datagram[ncm_interface.recv_glue_ntb_datagram_ndx].wDatagramLength == 0) {
+      TU_LOG_DRV("(EE) SOMETHING WENT WRONG 2\n");
+    } else {
+      uint16_t datagramIndex = ndp16_datagram[ncm_interface.recv_glue_ntb_datagram_ndx].wDatagramIndex;
+      uint16_t datagramLength = ndp16_datagram[ncm_interface.recv_glue_ntb_datagram_ndx].wDatagramLength;
 
-  switch ( request->bmRequestType_bit.type )
-  {
-    case TUSB_REQ_TYPE_STANDARD:
-      switch ( request->bRequest )
-      {
-        case TUSB_REQ_GET_INTERFACE:
-        {
-          uint8_t const req_itfnum = (uint8_t) request->wIndex;
-          TU_VERIFY(ncm_interface.itf_num + 1 == req_itfnum);
+      TU_LOG_DRV("  recv[%d] - %d %d\n", ncm_interface.recv_glue_ntb_datagram_ndx, datagramIndex, datagramLength);
+      if (tud_network_recv_cb(ncm_interface.recv_glue_ntb->data + datagramIndex, datagramLength)) {
+        // send datagram successfully to glue logic
+        TU_LOG_DRV("    OK\n");
+        datagramIndex = ndp16_datagram[ncm_interface.recv_glue_ntb_datagram_ndx + 1].wDatagramIndex;
+        datagramLength = ndp16_datagram[ncm_interface.recv_glue_ntb_datagram_ndx + 1].wDatagramLength;
 
-          tud_control_xfer(rhport, request, &ncm_interface.itf_data_alt, 1);
+        if (datagramIndex != 0 && datagramLength != 0) {
+          // -> next datagram
+          ++ncm_interface.recv_glue_ntb_datagram_ndx;
+        } else {
+          // end of datagrams reached
+          recv_put_ntb_into_free_list(ncm_interface.recv_glue_ntb);
+          ncm_interface.recv_glue_ntb = NULL;
         }
-          break;
+      }
+    }
+  }
+} // recv_transfer_datagram_to_glue_logic
 
-        case TUSB_REQ_SET_INTERFACE:
-        {
-          uint8_t const req_itfnum = (uint8_t) request->wIndex;
-          uint8_t const req_alt    = (uint8_t) request->wValue;
+//-----------------------------------------------------------------------------
+//
+// all the tud_network_*() stuff (glue logic -> driver)
+//
 
-          // Only valid for Data Interface with Alternate is either 0 or 1
-          TU_VERIFY(ncm_interface.itf_num + 1 == req_itfnum && req_alt < 2);
+/**
+ * Check if the glue logic is allowed to call tud_network_xmit().
+ * This function also fetches a next buffer if required, so that tud_network_xmit() is ready for copy
+ * and transmission operation.
+ */
+bool tud_network_can_xmit(uint16_t size) {
+  TU_LOG_DRV("tud_network_can_xmit(%d)\n", size);
 
-          if (req_alt != ncm_interface.itf_data_alt) {
-            ncm_interface.itf_data_alt = req_alt;
+  TU_ASSERT(size <= CFG_TUD_NCM_OUT_NTB_MAX_SIZE - (sizeof(nth16_t) + sizeof(ndp16_t) + 2 * sizeof(ndp16_datagram_t)), false);
 
-            if (ncm_interface.itf_data_alt) {
-              if (!usbd_edpt_busy(rhport, ncm_interface.ep_out)) {
-                tud_network_recv_renew(); // prepare for incoming datagrams
-              }
-              if (!ncm_interface.report_pending) {
-                ncm_report();
-              }
-            }
+  if (xmit_requested_datagram_fits_into_current_ntb(size) || xmit_setup_next_glue_ntb()) {
+    // -> everything is fine
+    return true;
+  }
+  xmit_start_if_possible(ncm_interface.rhport);
+  TU_LOG_DRV("(II) tud_network_can_xmit: request blocked\n");// could happen if all xmit buffers are full (but should happen rarely)
+  return false;
+} // tud_network_can_xmit
 
-            tud_network_link_state_cb(ncm_interface.itf_data_alt);
-          }
+/**
+ * Put a datagram into a waiting NTB.
+ * If currently no transmission is started, then initiate transmission.
+ */
+void tud_network_xmit(void *ref, uint16_t arg) {
+  TU_LOG_DRV("tud_network_xmit(%p, %d)\n", ref, arg);
 
-          tud_control_status(rhport, request);
-        }
-          break;
+  if (ncm_interface.xmit_glue_ntb == NULL) {
+    TU_LOG_DRV("(EE) tud_network_xmit: no buffer\n");// must not happen (really)
+    return;
+  }
 
-          // unsupported request
-        default: return false;
-      }
-      break;
+  xmit_ntb_t *ntb = ncm_interface.xmit_glue_ntb;
 
-    case TUSB_REQ_TYPE_CLASS:
-      TU_VERIFY (ncm_interface.itf_num == request->wIndex);
+  // copy new datagram to the end of the current NTB
+  uint16_t size = tud_network_xmit_cb(ntb->data + ntb->nth.wBlockLength, ref, arg);
 
-      if (NCM_GET_NTB_PARAMETERS == request->bRequest)
-      {
-        tud_control_xfer(rhport, request, (void*)(uintptr_t) &ntb_parameters, sizeof(ntb_parameters));
-      }
+  // correct NTB internals
+  ntb->ndp_datagram[ncm_interface.xmit_glue_ntb_datagram_ndx].wDatagramIndex = ntb->nth.wBlockLength;
+  ntb->ndp_datagram[ncm_interface.xmit_glue_ntb_datagram_ndx].wDatagramLength = size;
+  ncm_interface.xmit_glue_ntb_datagram_ndx += 1;
 
-      break;
+  ntb->nth.wBlockLength += (uint16_t) (size + XMIT_ALIGN_OFFSET(size));
 
-      // unsupported request
-    default: return false;
+  if (ntb->nth.wBlockLength > CFG_TUD_NCM_OUT_NTB_MAX_SIZE) {
+    TU_LOG_DRV("(EE) tud_network_xmit: buffer overflow\n"); // must not happen (really)
+    return;
   }
 
-  return true;
-}
+  xmit_start_if_possible(ncm_interface.rhport);
+} // tud_network_xmit
 
-static void handle_incoming_datagram(uint32_t len)
-{
-  uint32_t size = len;
+/**
+ * Keep the receive logic busy and transfer pending packets to the glue logic.
+ */
+void tud_network_recv_renew(void) {
+  TU_LOG_DRV("tud_network_recv_renew()\n");
 
-  if (len == 0) {
-    return;
-  }
+  recv_transfer_datagram_to_glue_logic();
+  recv_try_to_start_new_reception(ncm_interface.rhport);
+} // tud_network_recv_renew
 
-  TU_ASSERT(size >= sizeof(nth16_t), );
+/**
+ * Same as tud_network_recv_renew() but knows \a rhport
+ */
+void tud_network_recv_renew_r(uint8_t rhport) {
+  TU_LOG_DRV("tud_network_recv_renew_r(%d)\n", rhport);
 
-  const nth16_t *hdr = (const nth16_t *)receive_ntb;
-  TU_ASSERT(hdr->dwSignature == NTH16_SIGNATURE, );
-  TU_ASSERT(hdr->wNdpIndex >= sizeof(nth16_t) && (hdr->wNdpIndex + sizeof(ndp16_t)) <= len, );
+  ncm_interface.rhport = rhport;
+  tud_network_recv_renew();
+} // tud_network_recv_renew
 
-  const ndp16_t *ndp = (const ndp16_t *)(receive_ntb + hdr->wNdpIndex);
-  TU_ASSERT(ndp->dwSignature == NDP16_SIGNATURE_NCM0 || ndp->dwSignature == NDP16_SIGNATURE_NCM1, );
-  TU_ASSERT(hdr->wNdpIndex + ndp->wLength <= len, );
+//-----------------------------------------------------------------------------
+//
+// all the netd_*() stuff (interface TinyUSB -> driver)
+//
+/**
+ * Initialize the driver data structures.
+ * Might be called several times.
+ */
+void netd_init(void) {
+  TU_LOG_DRV("netd_init()\n");
 
-  int num_datagrams = (ndp->wLength - 12) / 4;
-  ncm_interface.current_datagram_index = 0;
-  ncm_interface.num_datagrams = 0;
-  ncm_interface.ndp = ndp;
-  for (int i = 0; i < num_datagrams && ndp->datagram[i].wDatagramIndex && ndp->datagram[i].wDatagramLength; i++)
-  {
-    ncm_interface.num_datagrams++;
+  memset(&ncm_interface, 0, sizeof(ncm_interface));
+
+  for (int i = 0; i < XMIT_NTB_N; ++i) {
+    ncm_interface.xmit_free_ntb[i] = ncm_interface.xmit_ntb + i;
   }
+  for (int i = 0; i < RECV_NTB_N; ++i) {
+    ncm_interface.recv_free_ntb[i] = ncm_interface.recv_ntb + i;
+  }
+} // netd_init
 
-  tud_network_recv_renew();
+/**
+ * Deinit driver
+ */
+bool netd_deinit(void) {
+  return true;
 }
 
-bool netd_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint32_t xferred_bytes)
-{
+/**
+ * Resets the port.
+ * In this driver this is the same as netd_init()
+ */
+void netd_reset(uint8_t rhport) {
   (void) rhport;
-  (void) result;
 
-  /* new datagram receive_ntb */
-  if (ep_addr == ncm_interface.ep_out )
-  {
-    handle_incoming_datagram(xferred_bytes);
-  }
+  netd_init();
+} // netd_reset
 
-  /* data transmission finished */
-  if (ep_addr == ncm_interface.ep_in )
-  {
-    if (ncm_interface.transferring) {
-      ncm_interface.transferring = false;
-    }
+/**
+ * Open the USB interface.
+ * - parse the USB descriptor \a TUD_CDC_NCM_DESCRIPTOR for itfnum and endpoints
+ * - a specific order of elements in the descriptor is tested.
+ *
+ * \note
+ *   Actually all of the information could be read directly from \a itf_desc, because the
+ *   structure and the values are well known.  But we do it this way.
+ *
+ * \post
+ * - \a itf_num set
+ * - \a ep_notif, \a ep_in and \a ep_out are set
+ * - USB interface is open
+ */
+uint16_t netd_open(uint8_t rhport, tusb_desc_interface_t const *itf_desc, uint16_t max_len) {
+  TU_ASSERT(ncm_interface.ep_notif == 0, 0);// assure that the interface is only opened once
 
-    // If there are datagrams queued up that we tried to send while this NTB was being emitted, send them now
-    if (ncm_interface.datagram_count && ncm_interface.itf_data_alt == 1) {
-      ncm_start_tx();
-    }
-  }
+  ncm_interface.itf_num = itf_desc->bInterfaceNumber;// management interface
 
-  if (ep_addr == ncm_interface.ep_notif )
-  {
-    ncm_interface.report_pending = false;
-    ncm_report();
+  // skip the two first entries and the following TUSB_DESC_CS_INTERFACE entries
+  uint16_t drv_len = sizeof(tusb_desc_interface_t);
+  uint8_t const *p_desc = tu_desc_next(itf_desc);
+  while (tu_desc_type(p_desc) == TUSB_DESC_CS_INTERFACE && drv_len <= max_len) {
+    drv_len += tu_desc_len(p_desc);
+    p_desc = tu_desc_next(p_desc);
   }
 
-  return true;
-}
+  // get notification endpoint
+  TU_ASSERT(tu_desc_type(p_desc) == TUSB_DESC_ENDPOINT, 0);
+  TU_ASSERT(usbd_edpt_open(rhport, (tusb_desc_endpoint_t const *) p_desc), 0);
+  ncm_interface.ep_notif = ((tusb_desc_endpoint_t const *) p_desc)->bEndpointAddress;
+  drv_len += tu_desc_len(p_desc);
+  p_desc = tu_desc_next(p_desc);
 
-// poll network driver for its ability to accept another packet to transmit
-bool tud_network_can_xmit(uint16_t size)
-{
-  TU_VERIFY(ncm_interface.itf_data_alt == 1);
+  // skip the following TUSB_DESC_INTERFACE entries (which must be TUSB_CLASS_CDC_DATA)
+  while (tu_desc_type(p_desc) == TUSB_DESC_INTERFACE && drv_len <= max_len) {
+    tusb_desc_interface_t const *data_itf_desc = (tusb_desc_interface_t const *) p_desc;
+    TU_ASSERT(data_itf_desc->bInterfaceClass == TUSB_CLASS_CDC_DATA, 0);
 
-  if (ncm_interface.datagram_count >= ncm_interface.max_datagrams_per_ntb) {
-    TU_LOG_DRV("NTB full [by count]\r\n");
-    return false;
+    drv_len += tu_desc_len(p_desc);
+    p_desc = tu_desc_next(p_desc);
   }
 
-  size_t next_datagram_offset = ncm_interface.next_datagram_offset;
-  if (next_datagram_offset + size > ncm_interface.ntb_in_size) {
-    TU_LOG_DRV("ntb full [by size]\r\n");
-    return false;
+  // a TUSB_DESC_ENDPOINT (actually two) must follow, open these endpoints
+  TU_ASSERT(tu_desc_type(p_desc) == TUSB_DESC_ENDPOINT, 0);
+  TU_ASSERT(usbd_open_edpt_pair(rhport, p_desc, 2, TUSB_XFER_BULK, &ncm_interface.ep_out, &ncm_interface.ep_in));
+  drv_len += 2 * sizeof(tusb_desc_endpoint_t);
+
+  return drv_len;
+} // netd_open
+
+/**
+ * Handle TinyUSB requests to process transfer events.
+ */
+bool netd_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint32_t xferred_bytes) {
+  (void) result;
+
+  if (ep_addr == ncm_interface.ep_out) {
+    // new NTB received
+    // - make the NTB valid
+    // - if ready transfer datagrams to the glue logic for further processing
+    // - if there is a free receive buffer, initiate reception
+    if (!recv_validate_datagram(ncm_interface.recv_tinyusb_ntb, xferred_bytes)) {
+      // verification failed: ignore NTB and return it to free
+      TU_LOG_DRV("(EE) VALIDATION FAILED. WHAT CAN WE DO IN THIS CASE?\n");
+    } else {
+      // packet ok -> put it into ready list
+      recv_put_ntb_into_ready_list(ncm_interface.recv_tinyusb_ntb);
+    }
+    ncm_interface.recv_tinyusb_ntb = NULL;
+    tud_network_recv_renew_r(rhport);
+  } else if (ep_addr == ncm_interface.ep_in) {
+    // transmission of an NTB finished
+    // - free the transmitted NTB buffer
+    // - insert ZLPs when necessary
+    // - if there is another transmit NTB waiting, try to start transmission
+    xmit_put_ntb_into_free_list(ncm_interface.xmit_tinyusb_ntb);
+    ncm_interface.xmit_tinyusb_ntb = NULL;
+    if (!xmit_insert_required_zlp(rhport, xferred_bytes)) {
+      xmit_start_if_possible(rhport);
+    }
+  } else if (ep_addr == ncm_interface.ep_notif) {
+    // next transfer on notification channel
+    notification_xmit(rhport, true);
   }
 
   return true;
-}
+} // netd_xfer_cb
 
-void tud_network_xmit(void *ref, uint16_t arg)
-{
-  transmit_ntb_t *ntb = &transmit_ntb[ncm_interface.current_ntb];
-  size_t next_datagram_offset = ncm_interface.next_datagram_offset;
+/**
+ * Respond to TinyUSB control requests.
+ * At startup transmission of notification packets are done here.
+ */
+bool netd_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb_control_request_t const *request) {
+  if (stage != CONTROL_STAGE_SETUP) {
+    return true;
+  }
 
-  uint16_t size = tud_network_xmit_cb(ntb->data + next_datagram_offset, ref, arg);
+  switch (request->bmRequestType_bit.type) {
+    case TUSB_REQ_TYPE_STANDARD:
 
-  ntb->ndp.datagram[ncm_interface.datagram_count].wDatagramIndex = ncm_interface.next_datagram_offset;
-  ntb->ndp.datagram[ncm_interface.datagram_count].wDatagramLength = size;
+      switch (request->bRequest) {
+        case TUSB_REQ_GET_INTERFACE: {
+          TU_VERIFY(ncm_interface.itf_num + 1 == request->wIndex, false);
 
-  ncm_interface.datagram_count++;
-  next_datagram_offset += size;
+          tud_control_xfer(rhport, request, &ncm_interface.itf_data_alt, 1);
+        } break;
 
-  // round up so the next datagram is aligned correctly
-  next_datagram_offset += (CFG_TUD_NCM_ALIGNMENT - 1);
-  next_datagram_offset -= (next_datagram_offset % CFG_TUD_NCM_ALIGNMENT);
+        case TUSB_REQ_SET_INTERFACE: {
+          TU_VERIFY(ncm_interface.itf_num + 1 == request->wIndex && request->wValue < 2, false);
 
-  ncm_interface.next_datagram_offset = next_datagram_offset;
+          ncm_interface.itf_data_alt = (uint8_t) request->wValue;
 
-  ncm_start_tx();
-}
+          if (ncm_interface.itf_data_alt == 1) {
+            tud_network_recv_renew_r(rhport);
+            notification_xmit(rhport, false);
+          }
+          tud_control_status(rhport, request);
+        } break;
 
-#endif
+        // unsupported request
+        default:
+          return false;
+      }
+      break;
+
+    case TUSB_REQ_TYPE_CLASS:
+      TU_VERIFY(ncm_interface.itf_num == request->wIndex, false);
+      switch (request->bRequest) {
+        case NCM_GET_NTB_PARAMETERS: {
+          // transfer NTB parameters to host.
+          tud_control_xfer(rhport, request, (void *) (uintptr_t) &ntb_parameters, sizeof(ntb_parameters));
+        } break;
+
+          // unsupported request
+        default:
+          return false;
+      }
+      break;
+      // unsupported request
+    default:
+      return false;
+  }
+
+  return true;
+} // netd_control_xfer_cb
+
+#endif // ( CFG_TUD_ENABLED && CFG_TUD_NCM )
diff --git a/src/class/net/net_device.h b/src/class/net/net_device.h
index da1a7b1e8..4c9a92f2d 100644
--- a/src/class/net/net_device.h
+++ b/src/class/net/net_device.h
@@ -28,14 +28,13 @@
 #ifndef _TUSB_NET_DEVICE_H_
 #define _TUSB_NET_DEVICE_H_
 
+#include <stdint.h>
 #include "class/cdc/cdc.h"
 
 #if CFG_TUD_ECM_RNDIS && CFG_TUD_NCM
 #error "Cannot enable both ECM_RNDIS and NCM network drivers"
 #endif
 
-#include "ncm.h"
-
 /* declared here, NOT in usb_descriptors.c, so that the driver can intelligently ZLP as needed */
 #define CFG_TUD_NET_ENDPOINT_SIZE (TUD_OPT_HIGH_SPEED ? 512 : 64)
 
@@ -44,21 +43,13 @@
 #define CFG_TUD_NET_MTU           1514
 #endif
 
-#ifndef CFG_TUD_NCM_IN_NTB_MAX_SIZE
-#define CFG_TUD_NCM_IN_NTB_MAX_SIZE 3200
-#endif
-
-#ifndef CFG_TUD_NCM_OUT_NTB_MAX_SIZE
-#define CFG_TUD_NCM_OUT_NTB_MAX_SIZE 3200
-#endif
 
-#ifndef CFG_TUD_NCM_MAX_DATAGRAMS_PER_NTB
-#define CFG_TUD_NCM_MAX_DATAGRAMS_PER_NTB 8
-#endif
+// Table 4.3 Data Class Interface Protocol Codes
+typedef enum
+{
+  NCM_DATA_PROTOCOL_NETWORK_TRANSFER_BLOCK = 0x01
+} ncm_data_interface_protocol_code_t;
 
-#ifndef CFG_TUD_NCM_ALIGNMENT
-#define CFG_TUD_NCM_ALIGNMENT 4
-#endif
 
 #ifdef __cplusplus
  extern "C" {
@@ -96,11 +87,6 @@ void tud_network_init_cb(void);
 // TODO removed later since it is not part of tinyusb stack
 extern uint8_t tud_network_mac_address[6];
 
-//------------- NCM -------------//
-
-// callback to client providing optional indication of internal state of network driver
-void tud_network_link_state_cb(bool state);
-
 //--------------------------------------------------------------------+
 // INTERNAL USBD-CLASS DRIVER API
 //--------------------------------------------------------------------+
diff --git a/src/class/usbtmc/usbtmc.h b/src/class/usbtmc/usbtmc.h
index 090ab3c4a..327de087c 100644
--- a/src/class/usbtmc/usbtmc.h
+++ b/src/class/usbtmc/usbtmc.h
@@ -184,6 +184,23 @@ typedef enum {
 } usmtmc_request_type_enum;
 
 typedef enum {
+  // The last and first valid bNotify1 for use by the USBTMC class specification.
+  USBTMC_bNOTIFY1_USBTMC_FIRST          = 0x00,
+  USBTMC_bNOTIFY1_USBTMC_LAST           = 0x3F,
+
+  // The last and first valid bNotify1 for use by vendors.
+  USBTMC_bNOTIFY1_VENDOR_SPECIFIC_FIRST = 0x40,
+  USBTMC_bNOTIFY1_VENDOR_SPECIFIC_LAST  = 0x7F,
+
+  // The last and first valid bNotify1 for use by USBTMC subclass specifications.
+  USBTMC_bNOTIFY1_SUBCLASS_FIRST        = 0x80,
+  USBTMC_bNOTIFY1_SUBCLASS_LAST         = 0xFF,
+
+  // From the USB488 Subclass Specification, Section 3.4.
+  USB488_bNOTIFY1_SRQ                   = 0x81,
+} usbtmc_int_in_payload_format;
+
+typedef enum {
   USBTMC_STATUS_SUCCESS = 0x01,
   USBTMC_STATUS_PENDING = 0x02,
   USBTMC_STATUS_FAILED = 0x80,
@@ -305,6 +322,14 @@ TU_VERIFY_STATIC(sizeof(usbtmc_read_stb_rsp_488_t) == 3u, "struct wrong length")
 
 typedef struct TU_ATTR_PACKED
 {
+  uint8_t bNotify1; // Must be USB488_bNOTIFY1_SRQ
+  uint8_t StatusByte;
+} usbtmc_srq_interrupt_488_t;
+
+TU_VERIFY_STATIC(sizeof(usbtmc_srq_interrupt_488_t) == 2u, "struct wrong length");
+
+typedef struct TU_ATTR_PACKED
+{
   struct TU_ATTR_PACKED
   {
       unsigned int bTag : 7;
diff --git a/src/class/usbtmc/usbtmc_device.c b/src/class/usbtmc/usbtmc_device.c
index f6cddfbd7..129ff465d 100644
--- a/src/class/usbtmc/usbtmc_device.c
+++ b/src/class/usbtmc/usbtmc_device.c
@@ -86,6 +86,11 @@ tu_static char logMsg[150];
 // imposes a minimum buffer size of 32 bytes.
 #define USBTMCD_BUFFER_SIZE (TUD_OPT_HIGH_SPEED ? 512 : 64)
 
+// Interrupt endpoint buffer size, default to 2 bytes as USB488 specification.
+#ifndef CFG_TUD_USBTMC_INT_EP_SIZE
+#define CFG_TUD_USBTMC_INT_EP_SIZE 2
+#endif
+
 /*
  * The state machine does not allow simultaneous reading and writing. This is
  * consistent with USBTMC.
@@ -124,13 +129,15 @@ typedef struct
   uint8_t ep_bulk_in;
   uint8_t ep_bulk_out;
   uint8_t ep_int_in;
+  uint32_t ep_bulk_in_wMaxPacketSize;
+  uint32_t ep_bulk_out_wMaxPacketSize;
   // IN buffer is only used for first packet, not the remainder
   // in order to deal with prepending header
   CFG_TUSB_MEM_ALIGN uint8_t ep_bulk_in_buf[USBTMCD_BUFFER_SIZE];
-  uint32_t ep_bulk_in_wMaxPacketSize;
   // OUT buffer receives one packet at a time
   CFG_TUSB_MEM_ALIGN uint8_t ep_bulk_out_buf[USBTMCD_BUFFER_SIZE];
-  uint32_t ep_bulk_out_wMaxPacketSize;
+  // Buffer int msg to ensure alignment and placement correctness
+  CFG_TUSB_MEM_ALIGN uint8_t ep_int_in_buf[CFG_TUD_USBTMC_INT_EP_SIZE];
 
   uint32_t transfer_size_remaining; // also used for requested length for bulk IN.
   uint32_t transfer_size_sent;      // To keep track of data bytes that have been queued in FIFO (not header bytes)
@@ -240,6 +247,19 @@ bool tud_usbtmc_transmit_dev_msg_data(
   return true;
 }
 
+bool tud_usbtmc_transmit_notification_data(const void * data, size_t len)
+{
+#ifndef NDEBUG
+  TU_ASSERT(len > 0);
+  TU_ASSERT(usbtmc_state.ep_int_in != 0);
+#endif
+  TU_VERIFY(usbd_edpt_busy(usbtmc_state.rhport, usbtmc_state.ep_int_in));
+
+  TU_VERIFY(tu_memcpy_s(usbtmc_state.ep_int_in_buf, sizeof(usbtmc_state.ep_int_in_buf), data, len) == 0);
+  TU_VERIFY(usbd_edpt_xfer(usbtmc_state.rhport, usbtmc_state.ep_int_in, usbtmc_state.ep_int_in_buf, (uint16_t)len));
+  return true;
+}
+
 void usbtmcd_init_cb(void)
 {
   usbtmc_state.capabilities = tud_usbtmc_get_capabilities_cb();
@@ -547,9 +567,10 @@ bool usbtmcd_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint
     case STATE_TX_INITIATED:
       if(usbtmc_state.transfer_size_remaining >= sizeof(usbtmc_state.ep_bulk_in_buf))
       {
-        // FIXME! This removes const below!
+        // Copy buffer to ensure alignment correctness
+        memcpy(usbtmc_state.ep_bulk_in_buf, usbtmc_state.devInBuffer, sizeof(usbtmc_state.ep_bulk_in_buf));
         TU_VERIFY( usbd_edpt_xfer(rhport, usbtmc_state.ep_bulk_in,
-            (void*)(uintptr_t) usbtmc_state.devInBuffer, sizeof(usbtmc_state.ep_bulk_in_buf)));
+            usbtmc_state.ep_bulk_in_buf, sizeof(usbtmc_state.ep_bulk_in_buf)));
         usbtmc_state.devInBuffer += sizeof(usbtmc_state.ep_bulk_in_buf);
         usbtmc_state.transfer_size_remaining -= sizeof(usbtmc_state.ep_bulk_in_buf);
         usbtmc_state.transfer_size_sent += sizeof(usbtmc_state.ep_bulk_in_buf);
@@ -585,7 +606,9 @@ bool usbtmcd_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint
     }
   }
   else if (ep_addr == usbtmc_state.ep_int_in) {
-    // Good?
+    if (tud_usbtmc_notification_complete_cb) {
+      TU_VERIFY(tud_usbtmc_notification_complete_cb());
+    }
     return true;
   }
   return false;
diff --git a/src/class/usbtmc/usbtmc_device.h b/src/class/usbtmc/usbtmc_device.h
index 3299a36eb..b85ef12b5 100644
--- a/src/class/usbtmc/usbtmc_device.h
+++ b/src/class/usbtmc/usbtmc_device.h
@@ -73,6 +73,10 @@ bool tud_usbtmc_check_abort_bulk_in_cb(usbtmc_check_abort_bulk_rsp_t *rsp);
 bool tud_usbtmc_check_abort_bulk_out_cb(usbtmc_check_abort_bulk_rsp_t *rsp);
 bool tud_usbtmc_check_clear_cb(usbtmc_get_clear_status_rsp_t *rsp);
 
+// The interrupt-IN endpoint buffer was transmitted to the host. Use
+// tud_usbtmc_transmit_notification_data to send another notification.
+TU_ATTR_WEAK bool tud_usbtmc_notification_complete_cb(void);
+
 // Indicator pulse should be 0.5 to 1.0 seconds long
 TU_ATTR_WEAK bool tud_usbtmc_indicator_pulse_cb(tusb_control_request_t const * msg, uint8_t *tmcResult);
 
@@ -82,17 +86,23 @@ TU_ATTR_WEAK bool tud_usbtmc_msg_trigger_cb(usbtmc_msg_generic_t* msg);
 //TU_ATTR_WEAK bool tud_usbtmc_app_go_to_local_cb();
 #endif
 
-/*******************************************
- * Called from app
- *
- * We keep a reference to the buffer, so it MUST not change until the app is
- * notified that the transfer is complete.
- ******************************************/
-
+// Called from app
+//
+// We keep a reference to the buffer, so it MUST not change until the app is
+// notified that the transfer is complete.
 bool tud_usbtmc_transmit_dev_msg_data(
     const void * data, size_t len,
     bool endOfMessage, bool usingTermChar);
 
+// Buffers a notification to be sent to the host. The data starts
+// with the bNotify1 field, see the USBTMC Specification, Table 13.
+//
+// If the previous notification data has not yet been sent, this
+// returns false.
+//
+// Requires an interrupt endpoint in the interface.
+bool tud_usbtmc_transmit_notification_data(const void * data, size_t len);
+
 bool tud_usbtmc_start_bus_read(void);
 
 
@@ -105,9 +115,4 @@ void     usbtmcd_reset_cb(uint8_t rhport);
 bool     usbtmcd_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint32_t xferred_bytes);
 bool     usbtmcd_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb_control_request_t const * request);
 
-/************************************************************
- * USBTMC Descriptor Templates
- *************************************************************/
-
-
 #endif /* CLASS_USBTMC_USBTMC_DEVICE_H_ */
diff --git a/src/class/vendor/vendor_device.c b/src/class/vendor/vendor_device.c
index e87ce3997..ca04d9a01 100644
--- a/src/class/vendor/vendor_device.c
+++ b/src/class/vendor/vendor_device.c
@@ -36,134 +36,103 @@
 //--------------------------------------------------------------------+
 // MACRO CONSTANT TYPEDEF
 //--------------------------------------------------------------------+
-typedef struct
-{
+typedef struct {
   uint8_t itf_num;
-  uint8_t ep_in;
-  uint8_t ep_out;
 
   /*------------- From this point, data is not cleared by bus reset -------------*/
-  tu_fifo_t rx_ff;
-  tu_fifo_t tx_ff;
+  // Endpoint Transfer buffer
+  CFG_TUD_MEM_ALIGN uint8_t epout_buf[CFG_TUD_VENDOR_EPSIZE];
+  CFG_TUD_MEM_ALIGN uint8_t epin_buf[CFG_TUD_VENDOR_EPSIZE];
 
-  uint8_t rx_ff_buf[CFG_TUD_VENDOR_RX_BUFSIZE];
-  uint8_t tx_ff_buf[CFG_TUD_VENDOR_TX_BUFSIZE];
+  struct {
+    tu_edpt_stream_t stream;
+    #if CFG_TUD_VENDOR_TX_BUFSIZE > 0
+    uint8_t ff_buf[CFG_TUD_VENDOR_TX_BUFSIZE];
+    #endif
+  }tx;
 
-  OSAL_MUTEX_DEF(rx_ff_mutex);
-  OSAL_MUTEX_DEF(tx_ff_mutex);
+  struct {
+    tu_edpt_stream_t stream;
+    #if CFG_TUD_VENDOR_RX_BUFSIZE > 0
+    uint8_t ff_buf[CFG_TUD_VENDOR_RX_BUFSIZE];
+    #endif
+  } rx;
 
-  // Endpoint Transfer buffer
-  CFG_TUSB_MEM_ALIGN uint8_t epout_buf[CFG_TUD_VENDOR_EPSIZE];
-  CFG_TUSB_MEM_ALIGN uint8_t epin_buf[CFG_TUD_VENDOR_EPSIZE];
 } vendord_interface_t;
 
-CFG_TUD_MEM_SECTION tu_static vendord_interface_t _vendord_itf[CFG_TUD_VENDOR];
+CFG_TUD_MEM_SECTION static vendord_interface_t _vendord_itf[CFG_TUD_VENDOR];
 
-#define ITF_MEM_RESET_SIZE   offsetof(vendord_interface_t, rx_ff)
-
-
-bool tud_vendor_n_mounted (uint8_t itf)
-{
-  return _vendord_itf[itf].ep_in && _vendord_itf[itf].ep_out;
-}
+#define ITF_MEM_RESET_SIZE   (offsetof(vendord_interface_t, itf_num) + sizeof(((vendord_interface_t *)0)->itf_num))
 
-uint32_t tud_vendor_n_available (uint8_t itf)
-{
-  return tu_fifo_count(&_vendord_itf[itf].rx_ff);
-}
+//--------------------------------------------------------------------
+// Application API
+//--------------------------------------------------------------------
 
-bool tud_vendor_n_peek(uint8_t itf, uint8_t* u8)
-{
-  return tu_fifo_peek(&_vendord_itf[itf].rx_ff, u8);
+bool tud_vendor_n_mounted(uint8_t itf) {
+  TU_VERIFY(itf < CFG_TUD_VENDOR);
+  vendord_interface_t* p_itf = &_vendord_itf[itf];
+  return p_itf->rx.stream.ep_addr || p_itf->tx.stream.ep_addr;
 }
 
 //--------------------------------------------------------------------+
 // Read API
 //--------------------------------------------------------------------+
-static void _prep_out_transaction (vendord_interface_t* p_itf)
-{
-  uint8_t const rhport = 0;
+uint32_t tud_vendor_n_available(uint8_t itf) {
+  TU_VERIFY(itf < CFG_TUD_VENDOR, 0);
+  vendord_interface_t* p_itf = &_vendord_itf[itf];
 
-    // claim endpoint
-  TU_VERIFY(usbd_edpt_claim(rhport, p_itf->ep_out), );
+  return tu_edpt_stream_read_available(&p_itf->rx.stream);
+}
 
-  // Prepare for incoming data but only allow what we can store in the ring buffer.
-  uint16_t max_read = tu_fifo_remaining(&p_itf->rx_ff);
-  if ( max_read >= CFG_TUD_VENDOR_EPSIZE )
-  {
-    usbd_edpt_xfer(rhport, p_itf->ep_out, p_itf->epout_buf, CFG_TUD_VENDOR_EPSIZE);
-  }
-  else
-  {
-    // Release endpoint since we don't make any transfer
-    usbd_edpt_release(rhport, p_itf->ep_out);
-  }
+bool tud_vendor_n_peek(uint8_t itf, uint8_t* u8) {
+  TU_VERIFY(itf < CFG_TUD_VENDOR);
+  vendord_interface_t* p_itf = &_vendord_itf[itf];
+
+  return tu_edpt_stream_peek(&p_itf->rx.stream, u8);
 }
 
-uint32_t tud_vendor_n_read (uint8_t itf, void* buffer, uint32_t bufsize)
-{
+uint32_t tud_vendor_n_read (uint8_t itf, void* buffer, uint32_t bufsize) {
+  TU_VERIFY(itf < CFG_TUD_VENDOR, 0);
   vendord_interface_t* p_itf = &_vendord_itf[itf];
-  uint32_t num_read = tu_fifo_read_n(&p_itf->rx_ff, buffer, (uint16_t) bufsize);
-  _prep_out_transaction(p_itf);
-  return num_read;
+  uint8_t const rhport = 0;
+
+  return tu_edpt_stream_read(rhport, &p_itf->rx.stream, buffer, bufsize);
 }
 
-void tud_vendor_n_read_flush (uint8_t itf)
-{
+void tud_vendor_n_read_flush (uint8_t itf) {
+  TU_VERIFY(itf < CFG_TUD_VENDOR, );
   vendord_interface_t* p_itf = &_vendord_itf[itf];
-  tu_fifo_clear(&p_itf->rx_ff);
-  _prep_out_transaction(p_itf);
+  uint8_t const rhport = 0;
+
+  tu_edpt_stream_clear(&p_itf->rx.stream);
+  tu_edpt_stream_read_xfer(rhport, &p_itf->rx.stream);
 }
 
 //--------------------------------------------------------------------+
 // Write API
 //--------------------------------------------------------------------+
-uint32_t tud_vendor_n_write (uint8_t itf, void const* buffer, uint32_t bufsize)
-{
+uint32_t tud_vendor_n_write (uint8_t itf, void const* buffer, uint32_t bufsize) {
+  TU_VERIFY(itf < CFG_TUD_VENDOR, 0);
   vendord_interface_t* p_itf = &_vendord_itf[itf];
-  uint16_t ret = tu_fifo_write_n(&p_itf->tx_ff, buffer, (uint16_t) bufsize);
+  uint8_t const rhport = 0;
 
-  // flush if queue more than packet size
-  if (tu_fifo_count(&p_itf->tx_ff) >= CFG_TUD_VENDOR_EPSIZE) {
-    tud_vendor_n_write_flush(itf);
-  }
-  return ret;
+  return tu_edpt_stream_write(rhport, &p_itf->tx.stream, buffer, (uint16_t) bufsize);
 }
 
-uint32_t tud_vendor_n_write_flush (uint8_t itf)
-{
+uint32_t tud_vendor_n_write_flush (uint8_t itf) {
+  TU_VERIFY(itf < CFG_TUD_VENDOR, 0);
   vendord_interface_t* p_itf = &_vendord_itf[itf];
-
-  // Skip if usb is not ready yet
-  TU_VERIFY( tud_ready(), 0 );
-
-  // No data to send
-  if ( !tu_fifo_count(&p_itf->tx_ff) ) return 0;
-
   uint8_t const rhport = 0;
 
-  // Claim the endpoint
-  TU_VERIFY( usbd_edpt_claim(rhport, p_itf->ep_in), 0 );
-
-  // Pull data from FIFO
-  uint16_t const count = tu_fifo_read_n(&p_itf->tx_ff, p_itf->epin_buf, sizeof(p_itf->epin_buf));
-
-  if ( count )
-  {
-    TU_ASSERT( usbd_edpt_xfer(rhport, p_itf->ep_in, p_itf->epin_buf, 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(rhport, p_itf->ep_in);
-    return 0;
-  }
+  return tu_edpt_stream_write_xfer(rhport, &p_itf->tx.stream);
 }
 
-uint32_t tud_vendor_n_write_available (uint8_t itf)
-{
-  return tu_fifo_remaining(&_vendord_itf[itf].tx_ff);
+uint32_t tud_vendor_n_write_available (uint8_t itf) {
+  TU_VERIFY(itf < CFG_TUD_VENDOR, 0);
+  vendord_interface_t* p_itf = &_vendord_itf[itf];
+  uint8_t const rhport = 0;
+
+  return tu_edpt_stream_write_available(rhport, &p_itf->tx.stream);
 }
 
 //--------------------------------------------------------------------+
@@ -175,70 +144,61 @@ void vendord_init(void) {
   for(uint8_t i=0; i<CFG_TUD_VENDOR; i++) {
     vendord_interface_t* p_itf = &_vendord_itf[i];
 
-    // config fifo
-    tu_fifo_config(&p_itf->rx_ff, p_itf->rx_ff_buf, CFG_TUD_VENDOR_RX_BUFSIZE, 1, false);
-    tu_fifo_config(&p_itf->tx_ff, p_itf->tx_ff_buf, CFG_TUD_VENDOR_TX_BUFSIZE, 1, false);
+    uint8_t* rx_ff_buf =
+                        #if CFG_TUD_VENDOR_RX_BUFSIZE > 0
+                          p_itf->rx.ff_buf;
+                        #else
+                          NULL;
+                        #endif
 
-    #if OSAL_MUTEX_REQUIRED
-    osal_mutex_t mutex_rd = osal_mutex_create(&p_itf->rx_ff_mutex);
-    osal_mutex_t mutex_wr = osal_mutex_create(&p_itf->tx_ff_mutex);
-    TU_ASSERT(mutex_rd && mutex_wr,);
+    tu_edpt_stream_init(&p_itf->rx.stream, false, false, false,
+                        rx_ff_buf, CFG_TUD_VENDOR_RX_BUFSIZE,
+                        p_itf->epout_buf, CFG_TUD_VENDOR_EPSIZE);
 
-    tu_fifo_config_mutex(&p_itf->rx_ff, NULL, mutex_rd);
-    tu_fifo_config_mutex(&p_itf->tx_ff, mutex_wr, NULL);
-    #endif
+    uint8_t* tx_ff_buf =
+                        #if CFG_TUD_VENDOR_TX_BUFSIZE > 0
+                          p_itf->tx.ff_buf;
+                        #else
+                          NULL;
+                        #endif
+
+    tu_edpt_stream_init(&p_itf->tx.stream, false, true, false,
+                        tx_ff_buf, CFG_TUD_VENDOR_TX_BUFSIZE,
+                        p_itf->epin_buf, CFG_TUD_VENDOR_EPSIZE);
   }
 }
 
 bool vendord_deinit(void) {
-  #if OSAL_MUTEX_REQUIRED
   for(uint8_t i=0; i<CFG_TUD_VENDOR; i++) {
     vendord_interface_t* p_itf = &_vendord_itf[i];
-    osal_mutex_t mutex_rd = p_itf->rx_ff.mutex_rd;
-    osal_mutex_t mutex_wr = p_itf->tx_ff.mutex_wr;
-
-    if (mutex_rd) {
-      osal_mutex_delete(mutex_rd);
-      tu_fifo_config_mutex(&p_itf->rx_ff, NULL, NULL);
-    }
-
-    if (mutex_wr) {
-      osal_mutex_delete(mutex_wr);
-      tu_fifo_config_mutex(&p_itf->tx_ff, NULL, NULL);
-    }
+    tu_edpt_stream_deinit(&p_itf->rx.stream);
+    tu_edpt_stream_deinit(&p_itf->tx.stream);
   }
-  #endif
-
   return true;
 }
 
-void vendord_reset(uint8_t rhport)
-{
+void vendord_reset(uint8_t rhport) {
   (void) rhport;
 
-  for(uint8_t i=0; i<CFG_TUD_VENDOR; i++)
-  {
+  for(uint8_t i=0; i<CFG_TUD_VENDOR; i++) {
     vendord_interface_t* p_itf = &_vendord_itf[i];
-
     tu_memclr(p_itf, ITF_MEM_RESET_SIZE);
-    tu_fifo_clear(&p_itf->rx_ff);
-    tu_fifo_clear(&p_itf->tx_ff);
+    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_close(&p_itf->tx.stream);
   }
 }
 
-uint16_t vendord_open(uint8_t rhport, tusb_desc_interface_t const * desc_itf, uint16_t max_len)
-{
+uint16_t vendord_open(uint8_t rhport, tusb_desc_interface_t const * desc_itf, uint16_t max_len) {
   TU_VERIFY(TUSB_CLASS_VENDOR_SPECIFIC == desc_itf->bInterfaceClass, 0);
-
-  uint8_t const * p_desc = tu_desc_next(desc_itf);
-  uint8_t const * desc_end = p_desc + max_len;
+  const uint8_t* p_desc = tu_desc_next(desc_itf);
+  const uint8_t* desc_end = p_desc + max_len;
 
   // Find available interface
   vendord_interface_t* p_vendor = NULL;
-  for(uint8_t i=0; i<CFG_TUD_VENDOR; i++)
-  {
-    if ( _vendord_itf[i].ep_in == 0 && _vendord_itf[i].ep_out == 0 )
-    {
+  for(uint8_t i=0; i<CFG_TUD_VENDOR; i++) {
+    if (!tud_vendor_n_mounted(i)) {
       p_vendor = &_vendord_itf[i];
       break;
     }
@@ -246,61 +206,68 @@ uint16_t vendord_open(uint8_t rhport, tusb_desc_interface_t const * desc_itf, ui
   TU_VERIFY(p_vendor, 0);
 
   p_vendor->itf_num = desc_itf->bInterfaceNumber;
-  if (desc_itf->bNumEndpoints)
-  {
+  uint8_t found_ep = 0;
+  while (found_ep < desc_itf->bNumEndpoints) {
     // skip non-endpoint descriptors
-    while ( (TUSB_DESC_ENDPOINT != tu_desc_type(p_desc)) && (p_desc < desc_end) )
-    {
+    while ( (TUSB_DESC_ENDPOINT != tu_desc_type(p_desc)) && (p_desc < desc_end) ) {
       p_desc = tu_desc_next(p_desc);
     }
+    if (p_desc >= desc_end) {
+      break;
+    }
 
-    // Open endpoint pair with usbd helper
-    TU_ASSERT(usbd_open_edpt_pair(rhport, p_desc, desc_itf->bNumEndpoints, TUSB_XFER_BULK, &p_vendor->ep_out, &p_vendor->ep_in), 0);
-
-    p_desc += desc_itf->bNumEndpoints*sizeof(tusb_desc_endpoint_t);
+    const tusb_desc_endpoint_t* desc_ep = (const tusb_desc_endpoint_t*) p_desc;
+    TU_ASSERT(usbd_edpt_open(rhport, desc_ep));
+    found_ep++;
 
-    // Prepare for incoming data
-    if ( p_vendor->ep_out )
-    {
-      _prep_out_transaction(p_vendor);
+    if (tu_edpt_dir(desc_ep->bEndpointAddress) == TUSB_DIR_IN) {
+      tu_edpt_stream_open(&p_vendor->tx.stream, desc_ep);
+      tud_vendor_n_write_flush((uint8_t)(p_vendor - _vendord_itf));
+    } else {
+      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
     }
 
-    if ( p_vendor->ep_in ) tud_vendor_n_write_flush((uint8_t)(p_vendor - _vendord_itf));
+    p_desc = tu_desc_next(p_desc);
   }
 
   return (uint16_t) ((uintptr_t) p_desc - (uintptr_t) desc_itf);
 }
 
-bool vendord_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint32_t xferred_bytes)
-{
-  (void) rhport;
+bool vendord_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint32_t xferred_bytes) {
   (void) result;
 
   uint8_t itf = 0;
   vendord_interface_t* p_itf = _vendord_itf;
 
-  for ( ; ; itf++, p_itf++)
-  {
-    if (itf >= TU_ARRAY_SIZE(_vendord_itf)) return false;
-
-    if ( ( ep_addr == p_itf->ep_out ) || ( ep_addr == p_itf->ep_in ) ) break;
+  for ( ; ; itf++, p_itf++) {
+    if (itf >= CFG_TUD_VENDOR) return false;
+    if ((ep_addr == p_itf->rx.stream.ep_addr) || (ep_addr == p_itf->tx.stream.ep_addr)) break;
   }
 
-  if ( ep_addr == p_itf->ep_out )
-  {
-    // Receive new data
-    tu_fifo_write_n(&p_itf->rx_ff, p_itf->epout_buf, (uint16_t) xferred_bytes);
+  if ( ep_addr == p_itf->rx.stream.ep_addr ) {
+    // Received new data: put into stream's fifo
+    tu_edpt_stream_read_xfer_complete(&p_itf->rx.stream, xferred_bytes);
 
     // Invoked callback if any
-    if (tud_vendor_rx_cb) tud_vendor_rx_cb(itf);
+    if (tud_vendor_rx_cb) {
+      tud_vendor_rx_cb(itf, p_itf->epout_buf, (uint16_t) xferred_bytes);
+    }
 
-    _prep_out_transaction(p_itf);
-  }
-  else if ( ep_addr == p_itf->ep_in )
-  {
-    if (tud_vendor_tx_cb) tud_vendor_tx_cb(itf, (uint16_t) xferred_bytes);
-    // Send complete, try to send more if possible
-    tud_vendor_n_write_flush(itf);
+    tu_edpt_stream_read_xfer(rhport, &p_itf->rx.stream);
+  } else if ( ep_addr == p_itf->tx.stream.ep_addr ) {
+    // Send complete
+    if (tud_vendor_tx_cb) {
+      tud_vendor_tx_cb(itf, (uint16_t) xferred_bytes);
+    }
+
+    #if CFG_TUD_VENDOR_TX_BUFSIZE > 0
+    // try to send more if possible
+    if ( 0 == tu_edpt_stream_write_xfer(rhport, &p_itf->tx.stream) ) {
+      // 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(rhport, &p_itf->tx.stream, xferred_bytes);
+    }
+    #endif
   }
 
   return true;
diff --git a/src/class/vendor/vendor_device.h b/src/class/vendor/vendor_device.h
index cd69ec7c6..149ae2d56 100644
--- a/src/class/vendor/vendor_device.h
+++ b/src/class/vendor/vendor_device.h
@@ -33,15 +33,24 @@
 #define CFG_TUD_VENDOR_EPSIZE     64
 #endif
 
+// RX FIFO can be disabled by setting this value to 0
+#ifndef CFG_TUD_VENDOR_RX_BUFSIZE
+#define CFG_TUD_VENDOR_RX_BUFSIZE    64
+#endif
+
+// TX FIFO can be disabled by setting this value to 0
+#ifndef CFG_TUD_VENDOR_TX_BUFSIZE
+#define CFG_TUD_VENDOR_TX_BUFSIZE    64
+#endif
+
 #ifdef __cplusplus
  extern "C" {
 #endif
 
 //--------------------------------------------------------------------+
-// Application API (Multiple Interfaces)
+// Application API (Multiple Interfaces) i.e CFG_TUD_VENDOR > 1
 //--------------------------------------------------------------------+
 bool     tud_vendor_n_mounted         (uint8_t itf);
-
 uint32_t tud_vendor_n_available       (uint8_t itf);
 uint32_t tud_vendor_n_read            (uint8_t itf, void* buffer, uint32_t bufsize);
 bool     tud_vendor_n_peek            (uint8_t itf, uint8_t* ui8);
@@ -51,89 +60,73 @@ uint32_t tud_vendor_n_write           (uint8_t itf, void const* buffer, uint32_t
 uint32_t tud_vendor_n_write_flush     (uint8_t itf);
 uint32_t tud_vendor_n_write_available (uint8_t itf);
 
-static inline uint32_t tud_vendor_n_write_str (uint8_t itf, char const* str);
+TU_ATTR_ALWAYS_INLINE static inline uint32_t tud_vendor_n_write_str (uint8_t itf, char const* str);
 
 // backward compatible
 #define tud_vendor_n_flush(itf) tud_vendor_n_write_flush(itf)
 
 //--------------------------------------------------------------------+
-// Application API (Single Port)
+// Application API (Single Port) i.e CFG_TUD_VENDOR = 1
 //--------------------------------------------------------------------+
-static inline bool     tud_vendor_mounted         (void);
-static inline uint32_t tud_vendor_available       (void);
-static inline uint32_t tud_vendor_read            (void* buffer, uint32_t bufsize);
-static inline bool     tud_vendor_peek            (uint8_t* ui8);
-static inline void     tud_vendor_read_flush      (void);
-static inline uint32_t tud_vendor_write           (void const* buffer, uint32_t bufsize);
-static inline uint32_t tud_vendor_write_str       (char const* str);
-static inline uint32_t tud_vendor_write_available (void);
-static inline uint32_t tud_vendor_write_flush     (void);
 
-// backward compatible
-#define tud_vendor_flush() tud_vendor_write_flush()
-
-//--------------------------------------------------------------------+
-// Application Callback API (weak is optional)
-//--------------------------------------------------------------------+
-
-// Invoked when received new data
-TU_ATTR_WEAK void tud_vendor_rx_cb(uint8_t itf);
-// Invoked when last rx transfer finished
-TU_ATTR_WEAK void tud_vendor_tx_cb(uint8_t itf, uint32_t sent_bytes);
-
-//--------------------------------------------------------------------+
-// Inline Functions
-//--------------------------------------------------------------------+
-
-static inline uint32_t tud_vendor_n_write_str (uint8_t itf, char const* str)
-{
-  return tud_vendor_n_write(itf, str, strlen(str));
+TU_ATTR_ALWAYS_INLINE static inline uint32_t tud_vendor_n_write_str(uint8_t itf, char const* str) {
+ return tud_vendor_n_write(itf, str, strlen(str));
 }
 
-static inline bool tud_vendor_mounted (void)
-{
-  return tud_vendor_n_mounted(0);
+TU_ATTR_ALWAYS_INLINE static inline bool tud_vendor_mounted(void) {
+ return tud_vendor_n_mounted(0);
 }
 
-static inline uint32_t tud_vendor_available (void)
-{
-  return tud_vendor_n_available(0);
+TU_ATTR_ALWAYS_INLINE static inline uint32_t tud_vendor_available(void) {
+ return tud_vendor_n_available(0);
 }
 
-static inline uint32_t tud_vendor_read (void* buffer, uint32_t bufsize)
-{
-  return tud_vendor_n_read(0, buffer, bufsize);
+TU_ATTR_ALWAYS_INLINE static inline uint32_t tud_vendor_read(void* buffer, uint32_t bufsize) {
+ return tud_vendor_n_read(0, buffer, bufsize);
 }
 
-static inline bool tud_vendor_peek (uint8_t* ui8)
-{
-  return tud_vendor_n_peek(0, ui8);
+TU_ATTR_ALWAYS_INLINE static inline bool tud_vendor_peek(uint8_t* ui8) {
+ return tud_vendor_n_peek(0, ui8);
 }
 
-static inline void tud_vendor_read_flush(void)
-{
-    tud_vendor_n_read_flush(0);
+TU_ATTR_ALWAYS_INLINE static inline void tud_vendor_read_flush(void) {
+ tud_vendor_n_read_flush(0);
 }
 
-static inline uint32_t tud_vendor_write (void const* buffer, uint32_t bufsize)
-{
-  return tud_vendor_n_write(0, buffer, bufsize);
+TU_ATTR_ALWAYS_INLINE static inline uint32_t tud_vendor_write(void const* buffer, uint32_t bufsize) {
+ return tud_vendor_n_write(0, buffer, bufsize);
 }
 
-static inline uint32_t tud_vendor_write_flush (void)
-{
-  return tud_vendor_n_write_flush(0);
+TU_ATTR_ALWAYS_INLINE static inline uint32_t tud_vendor_write_str(char const* str) {
+ return tud_vendor_n_write_str(0, str);
 }
 
-static inline uint32_t tud_vendor_write_str (char const* str)
-{
-  return tud_vendor_n_write_str(0, str);
+TU_ATTR_ALWAYS_INLINE static inline uint32_t tud_vendor_write_flush(void) {
+ return tud_vendor_n_write_flush(0);
 }
 
-static inline uint32_t tud_vendor_write_available (void)
-{
-  return tud_vendor_n_write_available(0);
+#if CFG_TUD_VENDOR_TX_BUFSIZE > 0
+TU_ATTR_ALWAYS_INLINE static inline uint32_t tud_vendor_write_available(void) {
+ return tud_vendor_n_write_available(0);
 }
+#endif
+
+// backward compatible
+#define tud_vendor_flush() tud_vendor_write_flush()
+
+//--------------------------------------------------------------------+
+// Application Callback API (weak is optional)
+//--------------------------------------------------------------------+
+
+// Invoked when received new data
+TU_ATTR_WEAK void tud_vendor_rx_cb(uint8_t itf, uint8_t const* buffer, uint16_t bufsize);
+// Invoked when last rx transfer finished
+TU_ATTR_WEAK void tud_vendor_tx_cb(uint8_t itf, uint32_t sent_bytes);
+
+//--------------------------------------------------------------------+
+// Inline Functions
+//--------------------------------------------------------------------+
+
 
 //--------------------------------------------------------------------+
 // Internal Class Driver API
diff --git a/src/class/video/video_device.c b/src/class/video/video_device.c
index 4218835aa..70dbb5b9e 100644
--- a/src/class/video/video_device.c
+++ b/src/class/video/video_device.c
@@ -398,7 +398,7 @@ static inline void const *_find_desc_format(void const *beg, void const *end, ui
     if ((fmt == VIDEO_CS_ITF_VS_FORMAT_UNCOMPRESSED ||
          fmt == VIDEO_CS_ITF_VS_FORMAT_MJPEG ||
          fmt == VIDEO_CS_ITF_VS_FORMAT_DV ||
-         fmt == VIDEO_CS_ITF_VS_FRAME_FRAME_BASED) &&
+         fmt == VIDEO_CS_ITF_VS_FORMAT_FRAME_BASED) &&
         fmtnum == p[3]) {
       return cur;
     }
@@ -707,7 +707,7 @@ static bool _open_vc_itf(uint8_t rhport, videod_interface_t *self, uint_fast8_t
 
   /* The first descriptor is a video control interface descriptor. */
   uint8_t const *cur = _find_desc_itf(beg, end, _desc_itfnum(beg), altnum);
-  TU_LOG_DRV("    cur %d\r\n", cur - beg);
+  TU_LOG_DRV("    cur %" PRId32 "\r\n", (int32_t) (cur - beg));
   TU_VERIFY(cur < end);
 
   tusb_desc_vc_itf_t const *vc = (tusb_desc_vc_itf_t const *)cur;