Merge pull request #84 from hathach/develop

better support device MIDI

42 files changed, 1172 insertions, 260 deletions

diff --git a/README.md b/README.md
index fca608494..8cd2c1eac 100644
--- a/README.md
+++ b/README.md
@@ -50,8 +50,8 @@ The stack supports the following MCUs
 
 - **Nordic:** nRF52840
 - **NXP:** LPC11Uxx, LPC13xx, LPC175x_6x, LPC177x_8x, LPC18xx, LPC40xx, LPC43xx
-- **MicroChip:** SAMD21, SAMD51
-- **ST:** STM32F4
+- **MicroChip:** SAMD21, SAMD51 (device only)
+- **ST:** STM32F4 (device only)
 
 [Here is the list of supported Boards](docs/boards.md)
 
diff --git a/docs/boards.md b/docs/boards.md
index da49d4a1f..dee2ceeb1 100644
--- a/docs/boards.md
+++ b/docs/boards.md
@@ -25,6 +25,7 @@ This code base already had supported for a handful of following boards
 
 ### MicroChip SAMD
 
+- [Adafruit Feather M4 Express](https://www.adafruit.com/product/3857)
 - [Adafruit Metro M0 Express](https://www.adafruit.com/product/3505)
 - [Adafruit Metro M4 Express](https://www.adafruit.com/product/3382)
 
diff --git a/examples/device/cdc_msc_hid/src/main.c b/examples/device/cdc_msc_hid/src/main.c
index 8ebdddd80..771638ac4 100644
--- a/examples/device/cdc_msc_hid/src/main.c
+++ b/examples/device/cdc_msc_hid/src/main.c
@@ -263,7 +263,7 @@ void led_blinking_task(void)
   static uint32_t start_ms = 0;
   static bool led_state = false;
 
-  // Blink every 1000 ms
+  // Blink every interval ms
   if ( board_millis() - start_ms < blink_interval_ms) return; // not enough time
   start_ms += blink_interval_ms;
 
diff --git a/examples/device/cdc_msc_hid/src/tusb_config.h b/examples/device/cdc_msc_hid/src/tusb_config.h
index 2c89a63b7..e55dc9d01 100644
--- a/examples/device/cdc_msc_hid/src/tusb_config.h
+++ b/examples/device/cdc_msc_hid/src/tusb_config.h
@@ -79,25 +79,16 @@
 #define CFG_TUD_MIDI                0
 #define CFG_TUD_CUSTOM_CLASS        0
 
-//------------- CDC -------------//
-
-// FIFO size of CDC TX and RX
+// CDC FIFO size of TX and RX
 #define CFG_TUD_CDC_RX_BUFSIZE      64
 #define CFG_TUD_CDC_TX_BUFSIZE      64
 
-//------------- MSC -------------//
-
-// Buffer size of Device Mass storage
+// MSC Buffer size of Device Mass storage
 #define CFG_TUD_MSC_BUFSIZE         512
 
-//------------- HID -------------//
-
-// Should be sufficient to hold ID (if any) + Data
+// HID buffer size Should be sufficient to hold ID (if any) + Data
 #define CFG_TUD_HID_BUFSIZE         16
 
-#define CFG_TUD_MIDI_RX_BUFSIZE     512
-#define CFG_TUD_MIDI_TX_BUFSIZE     512
-
 #ifdef __cplusplus
  }
 #endif
diff --git a/examples/device/cdc_msc_hid/src/usb_descriptors.c b/examples/device/cdc_msc_hid/src/usb_descriptors.c
index 8cd6062be..1692151a0 100644
--- a/examples/device/cdc_msc_hid/src/usb_descriptors.c
+++ b/examples/device/cdc_msc_hid/src/usb_descriptors.c
@@ -32,7 +32,7 @@
  *   [MSB]         HID | MSC | CDC          [LSB]
  */
 #define _PID_MAP(itf, n)  ( (CFG_TUD_##itf) << (n) )
-#define USB_PID           (0x4000 | _PID_MAP(CDC, 0) | _PID_MAP(MSC, 1) | _PID_MAP(HID, 2) )
+#define USB_PID           (0x4000 | _PID_MAP(CDC, 0) | _PID_MAP(MSC, 1) | _PID_MAP(HID, 2) | _PID_MAP(MIDI, 3) )
 
 //------------- Device Descriptors -------------//
 tusb_desc_device_t const desc_device =
@@ -188,6 +188,8 @@ uint16_t const* tud_descriptor_string_cb(uint8_t index)
     chr_count = 1;
   }else
   {
+    // Convert ASCII string into UTF-16
+
     if ( !(index < sizeof(string_desc_arr)/sizeof(string_desc_arr[0])) ) return NULL;
 
     const char* str = string_desc_arr[index];
diff --git a/examples/device/cdc_msc_hid_freertos/src/tusb_config.h b/examples/device/cdc_msc_hid_freertos/src/tusb_config.h
index b4e18de92..76ec948e5 100644
--- a/examples/device/cdc_msc_hid_freertos/src/tusb_config.h
+++ b/examples/device/cdc_msc_hid_freertos/src/tusb_config.h
@@ -79,20 +79,14 @@
 #define CFG_TUD_MIDI                0
 #define CFG_TUD_CUSTOM_CLASS        0
 
-//------------- CDC -------------//
-
-// FIFO size of CDC TX and RX
+// CDC FIFO size of TX and RX
 #define CFG_TUD_CDC_RX_BUFSIZE      64
 #define CFG_TUD_CDC_TX_BUFSIZE      64
 
-//------------- MSC -------------//
-
-// Buffer size of Device Mass storage
+// MSC Buffer size of Device Mass storage
 #define CFG_TUD_MSC_BUFSIZE         512
 
-//------------- HID -------------//
-
-// Should be sufficient to hold ID (if any) + Data
+// HID buffer size Should be sufficient to hold ID (if any) + Data
 #define CFG_TUD_HID_BUFSIZE         16
 
 #ifdef __cplusplus
diff --git a/examples/device/cdc_msc_hid_freertos/src/usb_descriptors.c b/examples/device/cdc_msc_hid_freertos/src/usb_descriptors.c
index b60615ca7..579e1ebcf 100644
--- a/examples/device/cdc_msc_hid_freertos/src/usb_descriptors.c
+++ b/examples/device/cdc_msc_hid_freertos/src/usb_descriptors.c
@@ -32,7 +32,7 @@
  *   [MSB]         HID | MSC | CDC          [LSB]
  */
 #define _PID_MAP(itf, n)  ( (CFG_TUD_##itf) << (n) )
-#define USB_PID           (0x4000 | _PID_MAP(CDC, 0) | _PID_MAP(MSC, 1) | _PID_MAP(HID, 2) )
+#define USB_PID           (0x4000 | _PID_MAP(CDC, 0) | _PID_MAP(MSC, 1) | _PID_MAP(HID, 2) | _PID_MAP(MIDI, 3) )
 
 //------------- Device Descriptors -------------//
 tusb_desc_device_t const desc_device =
@@ -126,7 +126,7 @@ enum
 
 uint8_t const desc_configuration[] =
 {
-  // Inteface count, string index, total length, attribute, power in mA
+  // interface count, string index, total length, attribute, power in mA
   TUD_CONFIG_DESCRIPTOR(ITF_NUM_TOTAL, 0, CONFIG_TOTAL_LEN, TUSB_DESC_CONFIG_ATT_REMOTE_WAKEUP, 100),
 
 #if CFG_TUD_CDC
@@ -189,6 +189,8 @@ uint16_t const* tud_descriptor_string_cb(uint8_t index)
     chr_count = 1;
   }else
   {
+    // Convert ASCII string into UTF-16
+
     if ( !(index < sizeof(string_desc_arr)/sizeof(string_desc_arr[0])) ) return NULL;
 
     const char* str = string_desc_arr[index];
diff --git a/examples/device/hid_generic_inout/src/main.c b/examples/device/hid_generic_inout/src/main.c
index bbc61a797..77d6cf7b5 100644
--- a/examples/device/hid_generic_inout/src/main.c
+++ b/examples/device/hid_generic_inout/src/main.c
@@ -154,7 +154,7 @@ void led_blinking_task(void)
   static uint32_t start_ms = 0;
   static bool led_state = false;
 
-  // Blink every 1000 ms
+  // Blink every interval ms
   if ( board_millis() - start_ms < blink_interval_ms) return; // not enough time
   start_ms += blink_interval_ms;
 
diff --git a/examples/device/hid_generic_inout/src/tusb_config.h b/examples/device/hid_generic_inout/src/tusb_config.h
index dc7d98812..fb19d5169 100644
--- a/examples/device/hid_generic_inout/src/tusb_config.h
+++ b/examples/device/hid_generic_inout/src/tusb_config.h
@@ -78,9 +78,7 @@
 #define CFG_TUD_MIDI                0
 #define CFG_TUD_CUSTOM_CLASS        0
 
-//------------- HID -------------//
-
-// Should be sufficient to hold ID (if any) + Data
+// HID buffer size Should be sufficient to hold ID (if any) + Data
 #define CFG_TUD_HID_BUFSIZE         64
 
 #ifdef __cplusplus
diff --git a/examples/device/hid_generic_inout/src/usb_descriptors.c b/examples/device/hid_generic_inout/src/usb_descriptors.c
index 3cf0f711b..ced915935 100644
--- a/examples/device/hid_generic_inout/src/usb_descriptors.c
+++ b/examples/device/hid_generic_inout/src/usb_descriptors.c
@@ -32,7 +32,7 @@
  *   [MSB]         HID | MSC | CDC          [LSB]
  */
 #define _PID_MAP(itf, n)  ( (CFG_TUD_##itf) << (n) )
-#define USB_PID           (0x4000 | _PID_MAP(CDC, 0) | _PID_MAP(MSC, 1) | _PID_MAP(HID, 2) )
+#define USB_PID           (0x4000 | _PID_MAP(CDC, 0) | _PID_MAP(MSC, 1) | _PID_MAP(HID, 2) | _PID_MAP(MIDI, 3) )
 
 //------------- Device Descriptors -------------//
 tusb_desc_device_t const desc_device =
@@ -81,7 +81,7 @@ enum
 
 uint8_t const desc_configuration[] =
 {
-  // Inteface count, string index, total length, attribute, power in mA
+  // interface count, string index, total length, attribute, power in mA
   TUD_CONFIG_DESCRIPTOR(ITF_NUM_TOTAL, 0, CONFIG_TOTAL_LEN, TUSB_DESC_CONFIG_ATT_REMOTE_WAKEUP, 100),
 
   // Interface number, string index, protocol, report descriptor len, EP In & Out address, size & polling interval
@@ -138,6 +138,8 @@ uint16_t const* tud_descriptor_string_cb(uint8_t index)
     chr_count = 1;
   }else
   {
+    // Convert ASCII string into UTF-16
+
     if ( !(index < sizeof(string_desc_arr)/sizeof(string_desc_arr[0])) ) return NULL;
 
     const char* str = string_desc_arr[index];
diff --git a/examples/device/midi_test/Makefile b/examples/device/midi_test/Makefile
new file mode 100644
index 000000000..5a455078e
--- /dev/null
+++ b/examples/device/midi_test/Makefile
@@ -0,0 +1,12 @@
+include ../../../tools/top.mk
+include ../../make.mk
+
+INC += \
+  src \
+  $(TOP)/hw \
+
+# Example source
+EXAMPLE_SOURCE += $(wildcard src/*.c)
+SRC_C += $(addprefix $(CURRENT_PATH)/, $(EXAMPLE_SOURCE))
+
+include ../../rules.mk
diff --git a/examples/device/midi_test/src/main.c b/examples/device/midi_test/src/main.c
new file mode 100644
index 000000000..0cb9b522d
--- /dev/null
+++ b/examples/device/midi_test/src/main.c
@@ -0,0 +1,167 @@
+/* 
+ * The MIT License (MIT)
+ *
+ * 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
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "bsp/board.h"
+#include "tusb.h"
+
+/* This MIDI example send sequence of note (on/off) repeatedly. To test on PC, you need to install
+ * synth software and midi connection management software. On
+ * - Linux (Ubuntu) : install qsynth, qjackctl. Then connect TinyUSB output port to FLUID Synth input port
+ *
+ */
+
+//--------------------------------------------------------------------+
+// MACRO CONSTANT TYPEDEF PROTYPES
+//--------------------------------------------------------------------+
+
+/* Blink pattern
+ * - 250 ms  : device not mounted
+ * - 1000 ms : device mounted
+ * - 2500 ms : device is suspended
+ */
+enum  {
+  BLINK_NOT_MOUNTED = 250,
+  BLINK_MOUNTED = 1000,
+  BLINK_SUSPENDED = 2500,
+};
+
+static uint32_t blink_interval_ms = BLINK_NOT_MOUNTED;
+
+void led_blinking_task(void);
+void midi_task(void);
+
+/*------------- MAIN -------------*/
+int main(void)
+{
+  board_init();
+
+  tusb_init();
+
+  while (1)
+  {
+    // tinyusb device task
+    tud_task();
+
+    led_blinking_task();
+
+    midi_task();
+  }
+
+  return 0;
+}
+
+//--------------------------------------------------------------------+
+// Device callbacks
+//--------------------------------------------------------------------+
+
+// Invoked when device is mounted
+void tud_mount_cb(void)
+{
+  blink_interval_ms = BLINK_MOUNTED;
+}
+
+// Invoked when device is unmounted
+void tud_umount_cb(void)
+{
+  blink_interval_ms = BLINK_NOT_MOUNTED;
+}
+
+// Invoked when usb bus is suspended
+// remote_wakeup_en : if host allow us  to perform remote wakeup
+// Within 7ms, device must draw an average of current less than 2.5 mA from bus
+void tud_suspend_cb(bool remote_wakeup_en)
+{
+  (void) remote_wakeup_en;
+  blink_interval_ms = BLINK_SUSPENDED;
+}
+
+// Invoked when usb bus is resumed
+void tud_resume_cb(void)
+{
+  blink_interval_ms = BLINK_MOUNTED;
+}
+
+//--------------------------------------------------------------------+
+// MIDI Task
+//--------------------------------------------------------------------+
+
+// Variable that holds the current position in the sequence.
+uint32_t note_pos = 0;
+
+// Store example melody as an array of note values
+uint8_t note_sequence[] =
+{
+  74,78,81,86,90,93,98,102,57,61,66,69,73,78,81,85,88,92,97,100,97,92,88,85,81,78,
+  74,69,66,62,57,62,66,69,74,78,81,86,90,93,97,102,97,93,90,85,81,78,73,68,64,61,
+  56,61,64,68,74,78,81,86,90,93,98,102
+};
+
+void midi_task(void)
+{
+  static uint32_t start_ms = 0;
+
+  // send note every 1000 ms
+  if (board_millis() - start_ms < 286) return; // not enough time
+  start_ms += 286;
+
+  // Previous positions in the note sequence.
+  int previous = note_pos - 1;
+
+  // If we currently are at position 0, set the
+  // previous position to the last note in the sequence.
+  if (previous < 0) previous = sizeof(note_sequence) - 1;
+
+  // Send Note On for current position at full velocity (127) on channel 1.
+  tudi_midi_write24(0, 0x90, note_sequence[note_pos], 127);
+
+  // Send Note Off for previous note.
+  tudi_midi_write24(0, 0x80, note_sequence[previous], 0);
+
+  // Increment position
+  note_pos++;
+
+  // If we are at the end of the sequence, start over.
+  if (note_pos >= sizeof(note_sequence)) note_pos = 0;
+}
+
+//--------------------------------------------------------------------+
+// BLINKING TASK
+//--------------------------------------------------------------------+
+void led_blinking_task(void)
+{
+  static uint32_t start_ms = 0;
+  static bool led_state = false;
+
+  // Blink every interval ms
+  if ( board_millis() - start_ms < blink_interval_ms) return; // not enough time
+  start_ms += blink_interval_ms;
+
+  board_led_write(led_state);
+  led_state = 1 - led_state; // toggle
+}
diff --git a/examples/device/midi_test/src/tusb_config.h b/examples/device/midi_test/src/tusb_config.h
new file mode 100644
index 000000000..6ea2f43db
--- /dev/null
+++ b/examples/device/midi_test/src/tusb_config.h
@@ -0,0 +1,89 @@
+/*
+ * The MIT License (MIT)
+ *
+ * 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
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ */
+
+#ifndef _TUSB_CONFIG_H_
+#define _TUSB_CONFIG_H_
+
+#ifdef __cplusplus
+ extern "C" {
+#endif
+
+//--------------------------------------------------------------------
+// COMMON CONFIGURATION
+//--------------------------------------------------------------------
+
+// defined by compiler flags for flexibility
+#ifndef CFG_TUSB_MCU
+  #error CFG_TUSB_MCU must be defined
+#endif
+
+#if CFG_TUSB_MCU == OPT_MCU_LPC43XX || CFG_TUSB_MCU == OPT_MCU_LPC18XX
+#define CFG_TUSB_RHPORT0_MODE       (OPT_MODE_DEVICE | OPT_MODE_HIGH_SPEED)
+#else
+#define CFG_TUSB_RHPORT0_MODE       OPT_MODE_DEVICE
+#endif
+
+#define CFG_TUSB_OS                 OPT_OS_NONE
+
+// CFG_TUSB_DEBUG is defined by compiler in DEBUG build
+// #define CFG_TUSB_DEBUG           0
+
+/* USB DMA on some MCUs can only access a specific SRAM region with restriction on alignment.
+ * Tinyusb use follows macros to declare transferring memory so that they can be put
+ * into those specific section.
+ * e.g
+ * - CFG_TUSB_MEM SECTION : __attribute__ (( section(".usb_ram") ))
+ * - CFG_TUSB_MEM_ALIGN   : __attribute__ ((aligned(4)))
+ */
+#ifndef CFG_TUSB_MEM_SECTION
+#define CFG_TUSB_MEM_SECTION
+#endif
+
+#ifndef CFG_TUSB_MEM_ALIGN
+#define CFG_TUSB_MEM_ALIGN          TU_ATTR_ALIGNED(4)
+#endif
+
+//--------------------------------------------------------------------
+// DEVICE CONFIGURATION
+//--------------------------------------------------------------------
+
+#define CFG_TUD_ENDOINT0_SIZE       64
+
+//------------- CLASS -------------//
+#define CFG_TUD_CDC                 0
+#define CFG_TUD_MSC                 0
+#define CFG_TUD_HID                 0
+#define CFG_TUD_MIDI                1
+#define CFG_TUD_CUSTOM_CLASS        0
+
+// MIDI FIFO size of TX and RX
+#define CFG_TUD_MIDI_RX_BUFSIZE     64
+#define CFG_TUD_MIDI_TX_BUFSIZE     64
+
+#ifdef __cplusplus
+ }
+#endif
+
+#endif /* _TUSB_CONFIG_H_ */
diff --git a/examples/device/midi_test/src/usb_descriptors.c b/examples/device/midi_test/src/usb_descriptors.c
new file mode 100644
index 000000000..192dacfbe
--- /dev/null
+++ b/examples/device/midi_test/src/usb_descriptors.c
@@ -0,0 +1,149 @@
+/* 
+ * The MIT License (MIT)
+ *
+ * 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
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ */
+
+#include "tusb.h"
+
+/* A combination of interfaces must have a unique product id, since PC will save device driver after the first plug.
+ * Same VID/PID with different interface e.g MSC (first), then CDC (later) will possibly cause system error on PC.
+ *
+ * Auto ProductID layout's Bitmap:
+ *   [MSB]       MIDI | HID | MSC | CDC          [LSB]
+ */
+#define _PID_MAP(itf, n)  ( (CFG_TUD_##itf) << (n) )
+#define USB_PID           (0x4000 | _PID_MAP(CDC, 0) | _PID_MAP(MSC, 1) | _PID_MAP(HID, 2) | _PID_MAP(MIDI, 3) )
+
+//------------- Device Descriptors -------------//
+tusb_desc_device_t const desc_device =
+{
+    .bLength            = sizeof(tusb_desc_device_t),
+    .bDescriptorType    = TUSB_DESC_DEVICE,
+    .bcdUSB             = 0x0200,
+    // Use Interface Association Descriptor (IAD) for Audio
+    // As required by USB Specs IAD's subclass must be common class (2) and protocol must be IAD (1)
+    .bDeviceClass       = TUSB_CLASS_MISC,
+    .bDeviceSubClass    = MISC_SUBCLASS_COMMON,
+    .bDeviceProtocol    = MISC_PROTOCOL_IAD,
+    .bMaxPacketSize0    = CFG_TUD_ENDOINT0_SIZE,
+
+    .idVendor           = 0xCafe,
+    .idProduct          = USB_PID,
+    .bcdDevice          = 0x0100,
+
+    .iManufacturer      = 0x01,
+    .iProduct           = 0x02,
+    .iSerialNumber      = 0x03,
+
+    .bNumConfigurations = 0x01
+};
+
+//------------- Configuration Descriptor -------------//
+enum
+{
+  ITF_NUM_MIDI = 0,
+  ITF_NUM_MIDI_STREAMING,
+  ITF_NUM_TOTAL
+};
+
+enum
+{
+  CONFIG_TOTAL_LEN = TUD_CONFIG_DESC_LEN + TUD_MIDI_DESC_LEN
+};
+
+// Use Endpoint 2 instead of 1 due to NXP MCU
+// LPC 17xx and 40xx endpoint type (bulk/interrupt/iso) are fixed by its number
+// 0 control, 1 In, 2 Bulk, 3 Iso, 4 In etc ...
+#define EPNUM_MIDI   0x02
+
+uint8_t const desc_configuration[] =
+{
+  // Interface count, string index, total length, attribute, power in mA
+  TUD_CONFIG_DESCRIPTOR(ITF_NUM_TOTAL, 0, CONFIG_TOTAL_LEN, TUSB_DESC_CONFIG_ATT_REMOTE_WAKEUP, 100),
+
+  // Interface number, string index, EP Out & EP In address, EP size
+  TUD_MIDI_DESCRIPTOR(ITF_NUM_MIDI, 0, EPNUM_MIDI, 0x80 | EPNUM_MIDI, (CFG_TUSB_RHPORT0_MODE & OPT_MODE_HIGH_SPEED) ? 512 : 64)
+};
+
+// Invoked when received GET DEVICE DESCRIPTOR
+// Application return pointer to descriptor
+uint8_t const * tud_descriptor_device_cb(void)
+{
+  return (uint8_t const *) &desc_device;
+}
+
+// Invoked when received GET CONFIGURATION DESCRIPTOR
+// Application return pointer to descriptor
+// Descriptor contents must exist long enough for transfer to complete
+uint8_t const * tud_descriptor_configuration_cb(uint8_t index)
+{
+  (void) index; // for multiple configurations
+  return desc_configuration;
+}
+
+//------------- String Descriptors -------------//
+
+// array of pointer to string descriptors
+char const* string_desc_arr [] =
+{
+  (const char[]) { 0x09, 0x04 }, // 0: is supported language is English (0x0409)
+  "TinyUSB",                     // 1: Manufacturer
+  "TinyUSB Device",              // 2: Product
+  "123456",                      // 3: Serials, should use chip ID
+};
+
+static uint16_t _desc_str[32];
+
+// Invoked when received GET STRING DESCRIPTOR request
+// Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
+uint16_t const* tud_descriptor_string_cb(uint8_t index)
+{
+  uint8_t chr_count;
+
+  if ( index == 0)
+  {
+    memcpy(&_desc_str[1], string_desc_arr[0], 2);
+    chr_count = 1;
+  }else
+  {
+    // Convert ASCII string into UTF-16
+
+    if ( !(index < sizeof(string_desc_arr)/sizeof(string_desc_arr[0])) ) return NULL;
+
+    const char* str = string_desc_arr[index];
+
+    // Cap at max char
+    chr_count = strlen(str);
+    if ( chr_count > 31 ) chr_count = 31;
+
+    for(uint8_t i=0; i<chr_count; i++)
+    {
+      _desc_str[1+i] = str[i];
+    }
+  }
+
+  // first byte is len, second byte is string type
+  _desc_str[0] = TUD_DESC_STR_HEADER(chr_count);
+
+  return _desc_str;
+}
diff --git a/examples/device/msc_dual_lun/src/main.c b/examples/device/msc_dual_lun/src/main.c
index 60500df93..060f20644 100644
--- a/examples/device/msc_dual_lun/src/main.c
+++ b/examples/device/msc_dual_lun/src/main.c
@@ -106,7 +106,7 @@ void led_blinking_task(void)
   static uint32_t start_ms = 0;
   static bool led_state = false;
 
-  // Blink every 1000 ms
+  // Blink every interval ms
   if ( board_millis() - start_ms < blink_interval_ms) return; // not enough time
   start_ms += blink_interval_ms;
 
diff --git a/examples/device/msc_dual_lun/src/tusb_config.h b/examples/device/msc_dual_lun/src/tusb_config.h
index ae57b4d60..db9974ea3 100644
--- a/examples/device/msc_dual_lun/src/tusb_config.h
+++ b/examples/device/msc_dual_lun/src/tusb_config.h
@@ -78,9 +78,7 @@
 #define CFG_TUD_MIDI                0
 #define CFG_TUD_CUSTOM_CLASS        0
 
-//------------- MSC -------------//
-
-// Buffer size of Device Mass storage
+// MSC Buffer size of Device Mass storage
 #define CFG_TUD_MSC_BUFSIZE         512
 
 #ifdef __cplusplus
diff --git a/examples/device/msc_dual_lun/src/usb_descriptors.c b/examples/device/msc_dual_lun/src/usb_descriptors.c
index 24bed9ecf..26ebe190c 100644
--- a/examples/device/msc_dual_lun/src/usb_descriptors.c
+++ b/examples/device/msc_dual_lun/src/usb_descriptors.c
@@ -32,7 +32,7 @@
  *   [MSB]         HID | MSC | CDC          [LSB]
  */
 #define _PID_MAP(itf, n)  ( (CFG_TUD_##itf) << (n) )
-#define USB_PID           (0x4000 | _PID_MAP(CDC, 0) | _PID_MAP(MSC, 1) | _PID_MAP(HID, 2) )
+#define USB_PID           (0x4000 | _PID_MAP(CDC, 0) | _PID_MAP(MSC, 1) | _PID_MAP(HID, 2) | _PID_MAP(MIDI, 3) )
 
 //------------- Device Descriptors -------------//
 tusb_desc_device_t const desc_device =
@@ -75,7 +75,7 @@ enum
 
 uint8_t const desc_configuration[] =
 {
-  // Inteface count, string index, total length, attribute, power in mA
+  // interface count, string index, total length, attribute, power in mA
   TUD_CONFIG_DESCRIPTOR(ITF_NUM_TOTAL, 0, CONFIG_TOTAL_LEN, TUSB_DESC_CONFIG_ATT_REMOTE_WAKEUP, 100),
 
   // Interface number, string index, EP Out & EP In address, EP size
@@ -123,6 +123,8 @@ uint16_t const* tud_descriptor_string_cb(uint8_t index)
     chr_count = 1;
   }else
   {
+    // Convert ASCII string into UTF-16
+
     if ( !(index < sizeof(string_desc_arr)/sizeof(string_desc_arr[0])) ) return NULL;
 
     const char* str = string_desc_arr[index];
diff --git a/examples/host/cdc_msc_hid/src/main.c b/examples/host/cdc_msc_hid/src/main.c
index 61f101127..8625bbcd0 100644
--- a/examples/host/cdc_msc_hid/src/main.c
+++ b/examples/host/cdc_msc_hid/src/main.c
@@ -169,7 +169,7 @@ void led_blinking_task(void)
 
   static bool led_state = false;
 
-  // Blink every 1000 ms
+  // Blink every interval ms
   if ( board_millis() - start_ms < interval_ms) return; // not enough time
   start_ms += interval_ms;
 
diff --git a/hw/bsp/feather_m4_express/board.mk b/hw/bsp/feather_m4_express/board.mk
new file mode 100644
index 000000000..c62d9bc33
--- /dev/null
+++ b/hw/bsp/feather_m4_express/board.mk
@@ -0,0 +1,47 @@
+CFLAGS += \
+  -D__SAMD51J19A__ \
+  -mthumb \
+  -mabi=aapcs-linux \
+  -mcpu=cortex-m4 \
+  -mfloat-abi=hard \
+  -mfpu=fpv4-sp-d16 \
+  -nostdlib -nostartfiles \
+  -DCFG_TUSB_MCU=OPT_MCU_SAMD51
+
+CFLAGS += -Wno-error=undef
+
+# All source paths should be relative to the top level.
+LD_FILE = hw/bsp/metro_m4_express/samd51g19a_flash.ld
+
+SRC_C += \
+	hw/mcu/microchip/samd/asf4/samd51/gcc/gcc/startup_samd51.c \
+	hw/mcu/microchip/samd/asf4/samd51/gcc/system_samd51.c \
+	hw/mcu/microchip/samd/asf4/samd51/hpl/gclk/hpl_gclk.c \
+	hw/mcu/microchip/samd/asf4/samd51/hpl/mclk/hpl_mclk.c \
+	hw/mcu/microchip/samd/asf4/samd51/hpl/osc32kctrl/hpl_osc32kctrl.c \
+	hw/mcu/microchip/samd/asf4/samd51/hpl/oscctrl/hpl_oscctrl.c \
+	hw/mcu/microchip/samd/asf4/samd51/hal/src/hal_atomic.c
+
+INC += \
+	$(TOP)/hw/mcu/microchip/samd/asf4/samd51/ \
+	$(TOP)/hw/mcu/microchip/samd/asf4/samd51/config \
+	$(TOP)/hw/mcu/microchip/samd/asf4/samd51/include \
+	$(TOP)/hw/mcu/microchip/samd/asf4/samd51/hal/include \
+	$(TOP)/hw/mcu/microchip/samd/asf4/samd51/hal/utils/include \
+	$(TOP)/hw/mcu/microchip/samd/asf4/samd51/hpl/port \
+	$(TOP)/hw/mcu/microchip/samd/asf4/samd51/hri \
+	$(TOP)/hw/mcu/microchip/samd/asf4/samd51/CMSIS/Include
+
+# For TinyUSB port source
+VENDOR = microchip
+CHIP_FAMILY = samd51
+
+# For freeRTOS port source
+FREERTOS_PORT = ARM_CM4F
+
+# For flash-jlink target
+JLINK_DEVICE = ATSAMD51J19
+JLINK_IF = swd
+
+# flash using jlink
+flash: flash-jlink
diff --git a/hw/bsp/feather_m4_express/board_feather_m4_express.c b/hw/bsp/feather_m4_express/board_feather_m4_express.c
new file mode 100644
index 000000000..2261e57b4
--- /dev/null
+++ b/hw/bsp/feather_m4_express/board_feather_m4_express.c
@@ -0,0 +1,120 @@
+/* 
+ * The MIT License (MIT)
+ *
+ * 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
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * This file is part of the TinyUSB stack.
+ */
+
+#include "bsp/board.h"
+
+#include "sam.h"
+#include "hal/include/hal_gpio.h"
+#include "hal/include/hal_init.h"
+#include "hpl/gclk/hpl_gclk_base.h"
+#include "hpl_mclk_config.h"
+
+//--------------------------------------------------------------------+
+// MACRO TYPEDEF CONSTANT ENUM DECLARATION
+//--------------------------------------------------------------------+
+#define LED_PIN      23
+#define BUTTON_PIN   22  // pin D12
+
+/* Referenced GCLKs, should be initialized firstly */
+#define _GCLK_INIT_1ST 0xFFFFFFFF
+
+/* Not referenced GCLKs, initialized last */
+#define _GCLK_INIT_LAST (~_GCLK_INIT_1ST)
+
+void board_init(void)
+{
+  // Clock init ( follow hpl_init.c )
+  hri_nvmctrl_set_CTRLA_RWS_bf(NVMCTRL, 0);
+
+  _osc32kctrl_init_sources();
+  _oscctrl_init_sources();
+  _mclk_init();
+#if _GCLK_INIT_1ST
+  _gclk_init_generators_by_fref(_GCLK_INIT_1ST);
+#endif
+  _oscctrl_init_referenced_generators();
+  _gclk_init_generators_by_fref(_GCLK_INIT_LAST);
+
+  // Led init
+  gpio_set_pin_direction(LED_PIN, GPIO_DIRECTION_OUT);
+  gpio_set_pin_level(LED_PIN, 0);
+
+  // Button init
+  gpio_set_pin_direction(BUTTON_PIN, GPIO_DIRECTION_IN);
+  gpio_set_pin_pull_mode(BUTTON_PIN, GPIO_PULL_UP);
+
+#if CFG_TUSB_OS  == OPT_OS_NONE
+  // 1ms tick timer (samd SystemCoreClock may not correct)
+  SysTick_Config(CONF_CPU_FREQUENCY / 1000);
+#endif
+
+  /* USB Clock init
+   * The USB module requires a GCLK_USB of 48 MHz ~ 0.25% clock
+   * for low speed and full speed operation. */
+  hri_gclk_write_PCHCTRL_reg(GCLK, USB_GCLK_ID, GCLK_PCHCTRL_GEN_GCLK1_Val | GCLK_PCHCTRL_CHEN);
+  hri_mclk_set_AHBMASK_USB_bit(MCLK);
+  hri_mclk_set_APBBMASK_USB_bit(MCLK);
+
+  // USB Pin Init
+  gpio_set_pin_direction(PIN_PA24, GPIO_DIRECTION_OUT);
+  gpio_set_pin_level(PIN_PA24, false);
+  gpio_set_pin_pull_mode(PIN_PA24, GPIO_PULL_OFF);
+  gpio_set_pin_direction(PIN_PA25, GPIO_DIRECTION_OUT);
+  gpio_set_pin_level(PIN_PA25, false);
+  gpio_set_pin_pull_mode(PIN_PA25, GPIO_PULL_OFF);
+
+  gpio_set_pin_function(PIN_PA24, PINMUX_PA24H_USB_DM);
+  gpio_set_pin_function(PIN_PA25, PINMUX_PA25H_USB_DP);
+}
+
+//--------------------------------------------------------------------+
+// Board porting API
+//--------------------------------------------------------------------+
+
+void board_led_write(bool state)
+{
+  gpio_set_pin_level(LED_PIN, state);
+}
+
+uint32_t board_button_read(void)
+{
+  // button is active low
+  return gpio_get_pin_level(BUTTON_PIN) ? 0 : 1;
+}
+
+#if CFG_TUSB_OS  == OPT_OS_NONE
+volatile uint32_t system_ticks = 0;
+
+void SysTick_Handler (void)
+{
+  system_ticks++;
+}
+
+uint32_t board_millis(void)
+{
+  return system_ticks;
+}
+#endif
diff --git a/hw/bsp/feather_m4_express/samd51g19a_flash.ld b/hw/bsp/feather_m4_express/samd51g19a_flash.ld
new file mode 100644
index 000000000..cf5db3800
--- /dev/null
+++ b/hw/bsp/feather_m4_express/samd51g19a_flash.ld
@@ -0,0 +1,164 @@
+/**
+ * \file
+ *
+ * \brief Linker script for running in internal FLASH on the SAMD51G19A
+ *
+ * Copyright (c) 2017 Microchip Technology Inc.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the Licence at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an AS IS BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * \asf_license_stop
+ *
+ */
+
+
+OUTPUT_FORMAT("elf32-littlearm", "elf32-littlearm", "elf32-littlearm")
+OUTPUT_ARCH(arm)
+SEARCH_DIR(.)
+
+/* Memory Spaces Definitions */
+MEMORY
+{
+  rom      (rx)  : ORIGIN = 0x00000000 + 16K, LENGTH = 0x00080000 - 16K
+  ram      (rwx) : ORIGIN = 0x20000000, LENGTH = 0x00030000
+  bkupram  (rwx) : ORIGIN = 0x47000000, LENGTH = 0x00002000
+  qspi     (rwx) : ORIGIN = 0x04000000, LENGTH = 0x01000000
+}
+
+/* The stack size used by the application. NOTE: you need to adjust according to your application. */
+STACK_SIZE = DEFINED(STACK_SIZE) ? STACK_SIZE : DEFINED(__stack_size__) ? __stack_size__ : 0xC000;
+
+/* Section Definitions */
+SECTIONS
+{
+    .text :
+    {
+        . = ALIGN(4);
+        _sfixed = .;
+        KEEP(*(.vectors .vectors.*))
+        *(.text .text.* .gnu.linkonce.t.*)
+        *(.glue_7t) *(.glue_7)
+        *(.rodata .rodata* .gnu.linkonce.r.*)
+        *(.ARM.extab* .gnu.linkonce.armextab.*)
+
+        /* Support C constructors, and C destructors in both user code
+           and the C library. This also provides support for C++ code. */
+        . = ALIGN(4);
+        KEEP(*(.init))
+        . = ALIGN(4);
+        __preinit_array_start = .;
+        KEEP (*(.preinit_array))
+        __preinit_array_end = .;
+
+        . = ALIGN(4);
+        __init_array_start = .;
+        KEEP (*(SORT(.init_array.*)))
+        KEEP (*(.init_array))
+        __init_array_end = .;
+
+        . = ALIGN(4);
+        KEEP (*crtbegin.o(.ctors))
+        KEEP (*(EXCLUDE_FILE (*crtend.o) .ctors))
+        KEEP (*(SORT(.ctors.*)))
+        KEEP (*crtend.o(.ctors))
+
+        . = ALIGN(4);
+        KEEP(*(.fini))
+
+        . = ALIGN(4);
+        __fini_array_start = .;
+        KEEP (*(.fini_array))
+        KEEP (*(SORT(.fini_array.*)))
+        __fini_array_end = .;
+
+        KEEP (*crtbegin.o(.dtors))
+        KEEP (*(EXCLUDE_FILE (*crtend.o) .dtors))
+        KEEP (*(SORT(.dtors.*)))
+        KEEP (*crtend.o(.dtors))
+
+        . = ALIGN(4);
+        _efixed = .;            /* End of text section */
+    } > rom
+
+    /* .ARM.exidx is sorted, so has to go in its own output section.  */
+    PROVIDE_HIDDEN (__exidx_start = .);
+    .ARM.exidx :
+    {
+      *(.ARM.exidx* .gnu.linkonce.armexidx.*)
+    } > rom
+    PROVIDE_HIDDEN (__exidx_end = .);
+
+    . = ALIGN(4);
+    _etext = .;
+
+    .relocate : AT (_etext)
+    {
+        . = ALIGN(4);
+        _srelocate = .;
+        *(.ramfunc .ramfunc.*);
+        *(.data .data.*);
+        . = ALIGN(4);
+        _erelocate = .;
+    } > ram
+
+    .bkupram (NOLOAD):
+    {
+        . = ALIGN(8);
+        _sbkupram = .;
+        *(.bkupram .bkupram.*);
+        . = ALIGN(8);
+        _ebkupram = .;
+    } > bkupram
+
+    .qspi (NOLOAD):
+    {
+        . = ALIGN(8);
+        _sqspi = .;
+        *(.qspi .qspi.*);
+        . = ALIGN(8);
+        _eqspi = .;
+    } > qspi
+
+    /* .bss section which is used for uninitialized data */
+    .bss (NOLOAD) :
+    {
+        . = ALIGN(4);
+        _sbss = . ;
+        _szero = .;
+        *(.bss .bss.*)
+        *(COMMON)
+        . = ALIGN(4);
+        _ebss = . ;
+        _ezero = .;
+        end = .;
+    } > ram
+
+    /* stack section */
+    .stack (NOLOAD):
+    {
+        . = ALIGN(8);
+        _sstack = .;
+        . = . + STACK_SIZE;
+        . = ALIGN(8);
+        _estack = .;
+    } > ram
+
+    . = ALIGN(4);
+    _end = . ;
+}
diff --git a/hw/bsp/metro_m4_express/board_metro_m4_express.c b/hw/bsp/metro_m4_express/board_metro_m4_express.c
index 7c1b9ace1..2abb44b40 100644
--- a/hw/bsp/metro_m4_express/board_metro_m4_express.c
+++ b/hw/bsp/metro_m4_express/board_metro_m4_express.c
@@ -36,7 +36,7 @@
 // MACRO TYPEDEF CONSTANT ENUM DECLARATION
 //--------------------------------------------------------------------+
 #define LED_PIN      16
-#define BUTTON_PIN   (32 + 17)  // pin D2
+#define BUTTON_PIN   17  // pin D12
 
 /* Referenced GCLKs, should be initialized firstly */
 #define _GCLK_INIT_1ST 0xFFFFFFFF
diff --git a/src/class/audio/audio.h b/src/class/audio/audio.h
index c655e79e2..83b8906d2 100644
--- a/src/class/audio/audio.h
+++ b/src/class/audio/audio.h
@@ -29,8 +29,8 @@
  *            Currently only MIDI subclass is supported

  *  @{ */

 

-#ifndef _TUSB_CDC_H__

-#define _TUSB_CDC_H__

+#ifndef _TUSB_AUDIO_H__

+#define _TUSB_AUDIO_H__

 

 #include "common/tusb_common.h"

 

@@ -41,9 +41,9 @@
 /// Audio Interface Subclass Codes

 typedef enum

 {

-  AUDIO_SUBCLASS_AUDIO_CONTROL = 0x01  , ///< Audio Control

-  AUDIO_SUBCLASS_AUDIO_STREAMING       , ///< Audio Streaming

-  AUDIO_SUBCLASS_MIDI_STREAMING       ,  ///< MIDI Streaming

+  AUDIO_SUBCLASS_CONTROL = 0x01  , ///< Audio Control

+  AUDIO_SUBCLASS_STREAMING       , ///< Audio Streaming

+  AUDIO_SUBCLASS_MIDI_STREAMING  , ///< MIDI Streaming

 } audio_subclass_type_t;

 

 /// Audio Protocol Codes

@@ -54,6 +54,40 @@ typedef enum
   AUDIO_PROTOCOL_V3                   = 0x30, ///< Version 3.0

 } audio_protocol_type_t;

 

+/// Audio Function Category Codes

+typedef enum

+{

+  AUDIO_FUNC_DESKTOP_SPEAKER    = 0x01,

+  AUDIO_FUNC_HOME_THEATER       = 0x02,

+  AUDIO_FUNC_MICROPHONE         = 0x03,

+  AUDIO_FUNC_HEADSET            = 0x04,

+  AUDIO_FUNC_TELEPHONE          = 0x05,

+  AUDIO_FUNC_CONVERTER          = 0x06,

+  AUDIO_FUNC_SOUND_RECODER      = 0x07,

+  AUDIO_FUNC_IO_BOX             = 0x08,

+  AUDIO_FUNC_MUSICAL_INSTRUMENT = 0x09,

+  AUDIO_FUNC_PRO_AUDIO          = 0x0A,

+  AUDIO_FUNC_AUDIO_VIDEO        = 0x0B,

+  AUDIO_FUNC_CONTROL_PANEL      = 0x0C

+} audio_function_t;

+

+/// Audio Class-Specific AC Interface Descriptor Subtypes

+typedef enum

+{

+  AUDIO_CS_INTERFACE_HEADER                = 0x01,

+  AUDIO_CS_INTERFACE_INPUT_TERMINAL        = 0x02,

+  AUDIO_CS_INTERFACE_OUTPUT_TERMINAL       = 0x03,

+  AUDIO_CS_INTERFACE_MIXER_UNIT            = 0x04,

+  AUDIO_CS_INTERFACE_SELECTOR_UNIT         = 0x05,

+  AUDIO_CS_INTERFACE_FEATURE_UNIT          = 0x06,

+  AUDIO_CS_INTERFACE_EFFECT_UNIT           = 0x07,

+  AUDIO_CS_INTERFACE_PROCESSING_UNIT       = 0x08,

+  AUDIO_CS_INTERFACE_EXTENSION_UNIT        = 0x09,

+  AUDIO_CS_INTERFACE_CLOCK_SOURCE          = 0x0A,

+  AUDIO_CS_INTERFACE_CLOCK_SELECTOR        = 0x0B,

+  AUDIO_CS_INTERFACE_CLOCK_MULTIPLIER      = 0x0C,

+  AUDIO_CS_INTERFACE_SAMPLE_RATE_CONVERTER = 0x0D,

+} audio_cs_interface_subtype_t;

 

 /** @} */

 

diff --git a/src/class/cdc/cdc.h b/src/class/cdc/cdc.h
index 2e865bdbb..9cc8b82e3 100644
--- a/src/class/cdc/cdc.h
+++ b/src/class/cdc/cdc.h
@@ -41,7 +41,7 @@
 /** \defgroup ClassDriver_CDC_Common Common Definitions

  *  @{ */

 

-

+// TODO remove

 /// CDC Pipe ID, used to indicate which pipe the API is addressing to (Notification, Out, In)

 typedef enum

 {

@@ -52,8 +52,9 @@ typedef enum
 }cdc_pipeid_t;

 

 //--------------------------------------------------------------------+

-// CDC COMMUNICATION INTERFACE CLASS

+// CDC Communication Interface Class

 //--------------------------------------------------------------------+

+

 /// Communication Interface Subclass Codes

 typedef enum

 {

@@ -117,7 +118,7 @@ typedef enum
 }cdc_func_desc_type_t;

 

 //--------------------------------------------------------------------+

-// CDC DATA INTERFACE CLASS

+// CDC Data Interface Class

 //--------------------------------------------------------------------+

 

 // SUBCLASS code of Data Interface is not used and should/must be zero

@@ -138,8 +139,9 @@ typedef enum{
 }cdc_data_protocol_type_t;

 

 //--------------------------------------------------------------------+

-// MANAGEMENT ELEMENT REQUEST (CONTROL ENDPOINT)

+// Management Element Request (Control Endpoint)

 //--------------------------------------------------------------------+

+

 /// Communication Interface Management Element Request Codes

 typedef enum

 {

@@ -189,8 +191,9 @@ typedef enum
 }cdc_management_request_t;

 

 //--------------------------------------------------------------------+

-// MANAGEMENT ELEMENENT NOTIFICATION (NOTIFICATION ENDPOINT)

+// Management Elemenent Notification (Notification Endpoint)

 //--------------------------------------------------------------------+

+

 /// Communication Interface Management Element Notification Codes

 typedef enum

 {

@@ -209,14 +212,15 @@ typedef enum
 }cdc_notification_request_t;

 

 //--------------------------------------------------------------------+

-// FUNCTIONAL DESCRIPTOR (COMMUNICATION INTERFACE)

+// Class Specific Functional Descriptor (Communication Interface)

 //--------------------------------------------------------------------+

+

 /// Header Functional Descriptor (Communication Interface)

 typedef struct TU_ATTR_PACKED

 {

   uint8_t bLength            ; ///< Size of this descriptor in bytes.

   uint8_t bDescriptorType    ; ///< Descriptor Type, must be Class-Specific

-  uint8_t bDescriptorSubType ; ///< Descriptor SubType one of above CDC_FUCN_DESC_

+  uint8_t bDescriptorSubType ; ///< Descriptor SubType one of above CDC_FUNC_DESC_

   uint16_t bcdCDC            ; ///< CDC release number in Binary-Coded Decimal

 }cdc_desc_func_header_t;

 

@@ -246,7 +250,7 @@ typedef struct TU_ATTR_PACKED
   uint8_t bDescriptorType     ; ///< Descriptor Type, must be Class-Specific

   uint8_t bDescriptorSubType  ; ///< Descriptor SubType one of above CDC_FUCN_DESC_

   uint8_t iCountryCodeRelDate ; ///< Index of a string giving the release date for the implemented ISO 3166 Country Codes.

-  uint16_t wCountryCode[]     ; ///< Country code in the format as defined in [ISO3166], release date as specified inoffset 3 for the first supported country.

+  uint16_t wCountryCode       ; ///< Country code in the format as defined in [ISO3166], release date as specified inoffset 3 for the first supported country.

 }cdc_desc_func_country_selection_t;

 

 #define cdc_desc_func_country_selection_n_t(no_country) \

diff --git a/src/class/cdc/cdc_device.c b/src/class/cdc/cdc_device.c
index 0a41147c9..6d13dafc0 100644
--- a/src/class/cdc/cdc_device.c
+++ b/src/class/cdc/cdc_device.c
@@ -73,21 +73,18 @@ typedef struct
 //--------------------------------------------------------------------+

 CFG_TUSB_MEM_SECTION static cdcd_interface_t _cdcd_itf[CFG_TUD_CDC];

 

-//bool pending_read_from_host; TODO remove

 static void _prep_out_transaction (uint8_t itf)

 {

   cdcd_interface_t* p_cdc = &_cdcd_itf[itf];

 

   // skip if previous transfer not complete

   if ( usbd_edpt_busy(TUD_OPT_RHPORT, p_cdc->ep_out) ) return;

-  //if (pending_read_from_host) return;

 

   // Prepare for incoming data but only allow what we can store in the ring buffer.

   uint16_t max_read = tu_fifo_remaining(&p_cdc->rx_ff);

   if ( max_read >= CFG_TUD_CDC_EPSIZE )

   {

     usbd_edpt_xfer(TUD_OPT_RHPORT, p_cdc->ep_out, p_cdc->epout_buf, CFG_TUD_CDC_EPSIZE);

-//    pending_read_from_host = true;

   }

 }

 

@@ -265,7 +262,7 @@ bool cdcd_open(uint8_t rhport, tusb_desc_interface_t const * itf_desc, uint16_t
   (*p_length) = sizeof(tusb_desc_interface_t);

 

   // Communication Functional Descriptors

-  while ( TUSB_DESC_CLASS_SPECIFIC == tu_desc_type(p_desc) )

+  while ( TUSB_DESC_CS_INTERFACE == tu_desc_type(p_desc) )

   {

     (*p_length) += tu_desc_len(p_desc);

     p_desc = tu_desc_next(p_desc);

@@ -296,7 +293,6 @@ bool cdcd_open(uint8_t rhport, tusb_desc_interface_t const * itf_desc, uint16_t
   }

 

   // Prepare for incoming data

-//  pending_read_from_host = false;

   _prep_out_transaction(cdc_id);

 

   return true;

@@ -374,7 +370,7 @@ bool cdcd_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint32_
   uint8_t const itf = 0;

   cdcd_interface_t* p_cdc = &_cdcd_itf[itf];

 

-  // receive new data

+  // Received new data

   if ( ep_addr == p_cdc->ep_out )

   {

     for(uint32_t i=0; i<xferred_bytes; i++)

@@ -392,11 +388,18 @@ bool cdcd_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint32_
     if (tud_cdc_rx_cb && tu_fifo_count(&p_cdc->rx_ff) ) tud_cdc_rx_cb(itf);

 

     // prepare for OUT transaction

-//    pending_read_from_host = false;

     _prep_out_transaction(itf);

   }

 

-  // nothing to do with in and notif endpoint for now

+  // Data sent to host, we could continue to fetch data tx fifo to send.

+  // But it will cause incorrect baudrate set in line coding.

+  // Though maybe the baudrate is not really important !!!

+//  if ( ep_addr == p_cdc->ep_in )

+//  {

+//

+//  }

+

+  // nothing to do with notif endpoint for now

 

   return true;

 }

diff --git a/src/class/cdc/cdc_device.h b/src/class/cdc/cdc_device.h
index 3c1af9dbf..8d09094a0 100644
--- a/src/class/cdc/cdc_device.h
+++ b/src/class/cdc/cdc_device.h
@@ -48,7 +48,7 @@
  *  @{ */

 

 //--------------------------------------------------------------------+

-// APPLICATION API (Multiple Interfaces)

+// Application API (Multiple Interfaces)

 // CFG_TUD_CDC > 1

 //--------------------------------------------------------------------+

 bool        tud_cdc_n_connected       (uint8_t itf);

@@ -68,26 +68,26 @@ uint32_t    tud_cdc_n_write_str       (uint8_t itf, char const* str);
 bool        tud_cdc_n_write_flush     (uint8_t itf);

 

 //--------------------------------------------------------------------+

-// APPLICATION API (Interface0)

+// Application API (Interface0)

 //--------------------------------------------------------------------+

-static inline bool        tud_cdc_connected       (void)                                 { return tud_cdc_n_connected(0);              }

-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)            { return tud_cdc_n_get_line_coding(0, coding);}

-static inline void        tud_cdc_set_wanted_char (char wanted)                          { tud_cdc_n_set_wanted_char(0, wanted);       }

+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 void        tud_cdc_set_wanted_char (char wanted);

 

-static inline uint32_t    tud_cdc_available       (void)                                 { return tud_cdc_n_available(0);              }

-static inline signed char tud_cdc_read_char       (void)                                 { return tud_cdc_n_read_char(0);              }

-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)                                 { tud_cdc_n_read_flush(0);                    }

-static inline signed char tud_cdc_peek            (int pos)                              { return tud_cdc_n_peek(0, pos);              }

+static inline uint32_t    tud_cdc_available       (void);

+static inline signed char 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 signed char tud_cdc_peek            (int pos);

 

-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) { return tud_cdc_n_write(0, buffer, bufsize); }

-static inline uint32_t    tud_cdc_write_str       (char const* str)                      { return tud_cdc_n_write_str(0, str);         }

-static inline bool        tud_cdc_write_flush     (void)                                 { return tud_cdc_n_write_flush(0);            }

+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 bool        tud_cdc_write_flush     (void);

 

 //--------------------------------------------------------------------+

-// APPLICATION CALLBACK API (WEAK is optional)

+// Application Callback API (weak is optional)

 //--------------------------------------------------------------------+

 

 // Invoked when received new data

@@ -102,6 +102,74 @@ 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);

 

+//--------------------------------------------------------------------+

+// Inline Functions

+//--------------------------------------------------------------------+

+static inline bool tud_cdc_connected (void)

+{

+  return tud_cdc_n_connected(0);

+}

+

+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)

+{

+  return tud_cdc_n_get_line_coding(0, coding);

+}

+

+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)

+{

+  return tud_cdc_n_available(0);

+}

+

+static inline signed char tud_cdc_read_char (void)

+{

+  return tud_cdc_n_read_char(0);

+}

+

+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)

+{

+  tud_cdc_n_read_flush(0);

+}

+

+static inline signed char tud_cdc_peek (int pos)

+{

+  return tud_cdc_n_peek(0, pos);

+}

+

+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)

+{

+  return tud_cdc_n_write(0, buffer, bufsize);

+}

+

+static inline uint32_t tud_cdc_write_str (char const* str)

+{

+  return tud_cdc_n_write_str(0, str);

+}

+

+static inline bool tud_cdc_write_flush (void)

+{

+  return tud_cdc_n_write_flush(0);

+}

+

 /** @} */

 /** @} */

 

diff --git a/src/class/cdc/cdc_host.c b/src/class/cdc/cdc_host.c
index b64d4a1fe..6a6f508b3 100644
--- a/src/class/cdc/cdc_host.c
+++ b/src/class/cdc/cdc_host.c
@@ -142,7 +142,7 @@ bool cdch_open(uint8_t rhport, uint8_t dev_addr, tusb_desc_interface_t const *it
   (*p_length) = sizeof(tusb_desc_interface_t);

 

   // Communication Functional Descriptors

-  while( TUSB_DESC_CLASS_SPECIFIC == p_desc[DESC_OFFSET_TYPE] )

+  while( TUSB_DESC_CS_INTERFACE == p_desc[DESC_OFFSET_TYPE] )

   {

     if ( CDC_FUNC_DESC_ABSTRACT_CONTROL_MANAGEMENT == cdc_functional_desc_typeof(p_desc) )

     {

diff --git a/src/class/midi/midi.h b/src/class/midi/midi.h
index 50f2be679..b3cc17af9 100644
--- a/src/class/midi/midi.h
+++ b/src/class/midi/midi.h
@@ -39,27 +39,122 @@
 #endif

 

 //--------------------------------------------------------------------+

-// FUNCTIONAL DESCRIPTOR (COMMUNICATION INTERFACE)

+// Class Specific Descriptor

 //--------------------------------------------------------------------+

-/// Header Functional Descriptor (Communication Interface)

+

+typedef enum

+{

+  MIDI_CS_INTERFACE_HEADER    = 0x01,

+  MIDI_CS_INTERFACE_IN_JACK   = 0x02,

+  MIDI_CS_INTERFACE_OUT_JACK  = 0x03,

+  MIDI_CS_INTERFACE_ELEMENT   = 0x04,

+} midi_cs_interface_subtype_t;

+

+typedef enum

+{

+  MIDI_CS_ENDPOINT_GENERAL = 0x01

+} midi_cs_endpoint_subtype_t;

+

+typedef enum

+{

+  MIDI_JACK_EMBEDDED = 0x01,

+  MIDI_JACK_EXTERNAL = 0x02

+} midi_jack_type_t;

+

+/// MIDI Interface Header Descriptor

 typedef struct TU_ATTR_PACKED

 {

   uint8_t bLength            ; ///< Size of this descriptor in bytes.

   uint8_t bDescriptorType    ; ///< Descriptor Type, must be Class-Specific

-  uint8_t bDescriptorSubType ; ///< Descriptor SubType one of above MIDI_FUCN_DESC_

+  uint8_t bDescriptorSubType ; ///< Descriptor SubType

   uint16_t bcdMSC            ; ///< MidiStreaming SubClass release number in Binary-Coded Decimal

   uint16_t wTotalLength      ;

-}midi_desc_func_header_t;

+} midi_desc_header_t;

+

+/// MIDI In Jack Descriptor

+typedef struct TU_ATTR_PACKED

+{

+  uint8_t bLength            ; ///< Size of this descriptor in bytes.

+  uint8_t bDescriptorType    ; ///< Descriptor Type, must be Class-Specific

+  uint8_t bDescriptorSubType ; ///< Descriptor SubType

+  uint8_t bJackType          ; ///< Embedded or External

+  uint8_t bJackID            ; ///< Unique ID for MIDI IN Jack

+  uint8_t iJack              ; ///< string descriptor

+} midi_desc_in_jack_t;

+

+

+/// MIDI Out Jack Descriptor with single pin

+typedef struct TU_ATTR_PACKED

+{

+  uint8_t bLength            ; ///< Size of this descriptor in bytes.

+  uint8_t bDescriptorType    ; ///< Descriptor Type, must be Class-Specific

+  uint8_t bDescriptorSubType ; ///< Descriptor SubType

+  uint8_t bJackType          ; ///< Embedded or External

+  uint8_t bJackID            ; ///< Unique ID for MIDI IN Jack

+  uint8_t bNrInputPins;

+

+  uint8_t baSourceID;

+  uint8_t baSourcePin;

+

+  uint8_t iJack              ; ///< string descriptor

+} midi_desc_out_jack_t ;

+

+/// MIDI Out Jack Descriptor with multiple pins

+#define midi_desc_out_jack_n_t(input_num) \

+  struct TU_ATTR_PACKED { \

+    uint8_t bLength            ; \

+    uint8_t bDescriptorType    ; \

+    uint8_t bDescriptorSubType ; \

+    uint8_t bJackType          ; \

+    uint8_t bJackID            ; \

+    uint8_t bNrInputPins       ; \

+    struct TU_ATTR_PACKED {      \

+        uint8_t baSourceID;      \

+        uint8_t baSourcePin;     \

+    } pins[input_num];           \

+   uint8_t iJack              ;  \

+  }

 

-/// Union Functional Descriptor (Communication Interface)

+/// MIDI Element Descriptor

 typedef struct TU_ATTR_PACKED

 {

-  uint8_t bLength                  ; ///< Size of this descriptor in bytes.

-  uint8_t bDescriptorType          ; ///< Descriptor Type, must be Class-Specific

-  uint8_t bDescriptorSubType       ; ///< Descriptor SubType one of above CDC_FUCN_DESC_

-  uint8_t bControlInterface        ; ///< Interface number of Communication Interface

-  uint8_t bSubordinateInterface    ; ///< Array of Interface number of Data Interface

-}cdc_desc_func_union_t;

+  uint8_t bLength            ; ///< Size of this descriptor in bytes.

+  uint8_t bDescriptorType    ; ///< Descriptor Type, must be Class-Specific

+  uint8_t bDescriptorSubType ; ///< Descriptor SubType

+  uint8_t bElementID;

+

+  uint8_t bNrInputPins;

+  uint8_t baSourceID;

+  uint8_t baSourcePin;

+

+  uint8_t bNrOutputPins;

+  uint8_t bInTerminalLink;

+  uint8_t bOutTerminalLink;

+  uint8_t bElCapsSize;

+

+  uint16_t bmElementCaps;

+  uint8_t  iElement;

+} midi_desc_element_t;

+

+/// MIDI Element Descriptor with multiple pins

+#define midi_desc_element_n_t(input_num) \

+  struct TU_ATTR_PACKED {       \

+    uint8_t bLength;            \

+    uint8_t bDescriptorType;    \

+    uint8_t bDescriptorSubType; \

+    uint8_t bElementID;         \

+    uint8_t bNrInputPins;       \

+    struct TU_ATTR_PACKED {     \

+        uint8_t baSourceID;     \

+        uint8_t baSourcePin;    \

+    } pins[input_num];          \

+    uint8_t bNrOutputPins;      \

+    uint8_t bInTerminalLink;    \

+    uint8_t bOutTerminalLink;   \

+    uint8_t bElCapsSize;        \

+    uint16_t bmElementCaps;     \

+    uint8_t  iElement;          \

+ }

 

 /** @} */

 

diff --git a/src/class/midi/midi_device.c b/src/class/midi/midi_device.c
index 2454db47e..76776d71c 100644
--- a/src/class/midi/midi_device.c
+++ b/src/class/midi/midi_device.c
@@ -74,7 +74,8 @@ typedef struct
 //--------------------------------------------------------------------+

 CFG_TUSB_MEM_SECTION midid_interface_t _midid_itf[CFG_TUD_MIDI];

 

-bool tud_midi_n_connected(uint8_t itf) {

+bool tud_midi_n_mounted (uint8_t itf)

+{

   midid_interface_t* midi = &_midid_itf[itf];

   return midi->itf_num != 0;

 }

@@ -87,12 +88,6 @@ uint32_t tud_midi_n_available(uint8_t itf, uint8_t jack_id)
   return tu_fifo_count(&_midid_itf[itf].rx_ff);

 }

 

-char tud_midi_n_read_char(uint8_t itf, uint8_t jack_id)

-{

-  char ch;

-  return tu_fifo_read(&_midid_itf[itf].rx_ff, &ch) ? ch : (-1);

-}

-

 uint32_t tud_midi_n_read(uint8_t itf, uint8_t jack_id, void* buffer, uint32_t bufsize)

 {

   return tu_fifo_read_n(&_midid_itf[itf].rx_ff, buffer, bufsize);

@@ -103,7 +98,6 @@ void tud_midi_n_read_flush (uint8_t itf, uint8_t jack_id)
   tu_fifo_clear(&_midid_itf[itf].rx_ff);

 }

 

-

 void midi_rx_done_cb(midid_interface_t* midi, uint8_t const* buffer, uint32_t bufsize) {

   if (bufsize % 4 != 0) {

     return;

@@ -133,15 +127,14 @@ void midi_rx_done_cb(midid_interface_t* midi, uint8_t const* buffer, uint32_t bu
 

 static bool maybe_transmit(midid_interface_t* midi, uint8_t itf_index)

 {

-    TU_VERIFY( !usbd_edpt_busy(TUD_OPT_RHPORT, midi->ep_in) ); // skip if previous transfer not complete

+  TU_VERIFY( !usbd_edpt_busy(TUD_OPT_RHPORT, midi->ep_in) ); // skip if previous transfer not complete

 

-    uint16_t count = tu_fifo_read_n(&midi->tx_ff, midi->epin_buf, CFG_TUD_MIDI_EPSIZE);

-    if (count > 0)

-    {

-      TU_VERIFY( tud_midi_n_connected(itf_index) ); // fifo is empty if not connected

-      TU_ASSERT( usbd_edpt_xfer(TUD_OPT_RHPORT, midi->ep_in, midi->epin_buf, count) );

-    }

-    return true;

+  uint16_t count = tu_fifo_read_n(&midi->tx_ff, midi->epin_buf, CFG_TUD_MIDI_EPSIZE);

+  if (count > 0)

+  {

+    TU_ASSERT( usbd_edpt_xfer(TUD_OPT_RHPORT, midi->ep_in, midi->epin_buf, count) );

+  }

+  return true;

 }

 

 uint32_t tud_midi_n_write(uint8_t itf, uint8_t jack_id, uint8_t const* buffer, uint32_t bufsize)

@@ -252,7 +245,7 @@ void midid_reset(uint8_t rhport)
 bool midid_open(uint8_t rhport, tusb_desc_interface_t const * p_interface_desc, uint16_t *p_length)

 {

   // For now handle the audio control interface as well.

-  if ( AUDIO_SUBCLASS_AUDIO_CONTROL == p_interface_desc->bInterfaceSubClass) {

+  if ( AUDIO_SUBCLASS_CONTROL == p_interface_desc->bInterfaceSubClass) {

     uint8_t const * p_desc = tu_desc_next ( (uint8_t const *) p_interface_desc );

     (*p_length) = sizeof(tusb_desc_interface_t);

 

diff --git a/src/class/midi/midi_device.h b/src/class/midi/midi_device.h
index 45e009010..490abaf89 100644
--- a/src/class/midi/midi_device.h
+++ b/src/class/midi/midi_device.h
@@ -29,7 +29,9 @@
 

 #include "common/tusb_common.h"

 #include "device/usbd.h"

+

 #include "class/audio/audio.h"

+#include "midi.h"

 

 //--------------------------------------------------------------------+

 // Class Driver Configuration

@@ -38,7 +40,6 @@
 #define CFG_TUD_MIDI_EPSIZE 64

 #endif

 

-

 #ifdef __cplusplus

  extern "C" {

 #endif

@@ -49,42 +50,75 @@
  *  @{ */

 

 //--------------------------------------------------------------------+

-// APPLICATION API (Multiple Interfaces)

+// Application API (Multiple Interfaces)

 // CFG_TUD_MIDI > 1

 //--------------------------------------------------------------------+

-bool     tud_midi_n_connected       (uint8_t itf);

+bool     tud_midi_n_mounted    (uint8_t itf);

+uint32_t tud_midi_n_available  (uint8_t itf, uint8_t jack_id);

+uint32_t tud_midi_n_read       (uint8_t itf, uint8_t jack_id, void* buffer, uint32_t bufsize);

+void     tud_midi_n_read_flush (uint8_t itf, uint8_t jack_id);

+uint32_t tud_midi_n_write      (uint8_t itf, uint8_t jack_id, uint8_t const* buffer, uint32_t bufsize);

 

-uint32_t tud_midi_n_available       (uint8_t itf, uint8_t jack_id);

-char     tud_midi_n_read_char       (uint8_t itf, uint8_t jack_id);

-uint32_t tud_midi_n_read            (uint8_t itf, uint8_t jack_id, void* buffer, uint32_t bufsize);

-void     tud_midi_n_read_flush      (uint8_t itf, uint8_t jack_id);

-char     tud_midi_n_peek            (uint8_t itf, uint8_t jack_id, int pos);

-

-uint32_t tud_midi_n_write_char      (uint8_t itf, char ch);

-uint32_t tud_midi_n_write           (uint8_t itf, uint8_t jack_id, uint8_t const* buffer, uint32_t bufsize);

-bool     tud_midi_n_write_flush     (uint8_t itf);

+static inline

+uint32_t tud_midi_n_write24    (uint8_t itf, uint8_t jack_id, uint8_t b1, uint8_t b2, uint8_t b3);

 

 //--------------------------------------------------------------------+

-// APPLICATION API (Interface0)

+// Application API (Interface0)

 //--------------------------------------------------------------------+

-static inline bool     tud_midi_connected       (void)                                 { return tud_midi_n_connected(0);              }

-

-static inline uint32_t tud_midi_available       (void)                                 { return tud_midi_n_available(0, 0);              }

-static inline char     tud_midi_read_char       (void)                                 { return tud_midi_n_read_char(0, 0);              }

-static inline uint32_t tud_midi_read            (void* buffer, uint32_t bufsize)       { return tud_midi_n_read(0, 0, buffer, bufsize);  }

-static inline void     tud_midi_read_flush      (void)                                 { tud_midi_n_read_flush(0, 0);                    }

-static inline char     tud_midi_peek            (int pos)                              { return tud_midi_n_peek(0, 0, pos);              }

-

-static inline uint32_t tud_midi_write_char      (char ch)                              { return tud_midi_n_write_char(0, ch);         }

-static inline uint32_t tud_midi_write           (uint8_t jack_id, void const* buffer, uint32_t bufsize) { return tud_midi_n_write(0, jack_id, buffer, bufsize); }

-static inline bool     tud_midi_write_flush     (void)                                 { return tud_midi_n_write_flush(0);            }

+static inline bool     tud_midi_mounted    (void);

+static inline uint32_t tud_midi_available  (void);

+static inline uint32_t tud_midi_read       (void* buffer, uint32_t bufsize);

+static inline void     tud_midi_read_flush (void);

+static inline uint32_t tud_midi_write      (uint8_t jack_id, uint8_t const* buffer, uint32_t bufsize);

+static inline uint32_t tudi_midi_write24   (uint8_t jack_id, uint8_t b1, uint8_t b2, uint8_t b3);

 

 //--------------------------------------------------------------------+

-// APPLICATION CALLBACK API (WEAK is optional)

+// Application Callback API (weak is optional)

 //--------------------------------------------------------------------+

 TU_ATTR_WEAK void tud_midi_rx_cb(uint8_t itf);

 

 //--------------------------------------------------------------------+

+// Inline Functions

+//--------------------------------------------------------------------+

+

+static inline uint32_t tud_midi_n_write24 (uint8_t itf, uint8_t jack_id, uint8_t b1, uint8_t b2, uint8_t b3)

+{

+  uint8_t msg[3] = { b1, b2, b3 };

+  return tud_midi_n_write(itf, jack_id, msg, 3);

+}

+

+static inline bool tud_midi_mounted (void)

+{

+  return tud_midi_n_mounted(0);

+}

+

+static inline uint32_t tud_midi_available (void)

+{

+  return tud_midi_n_available(0, 0);

+}

+

+static inline uint32_t tud_midi_read (void* buffer, uint32_t bufsize)

+{

+  return tud_midi_n_read(0, 0, buffer, bufsize);

+}

+

+static inline void tud_midi_read_flush (void)

+{

+  tud_midi_n_read_flush(0, 0);

+}

+

+static inline uint32_t tud_midi_write (uint8_t jack_id, uint8_t const* buffer, uint32_t bufsize)

+{

+  return tud_midi_n_write(0, jack_id, buffer, bufsize);

+}

+

+static inline uint32_t tudi_midi_write24 (uint8_t jack_id, uint8_t b1, uint8_t b2, uint8_t b3)

+{

+  uint8_t msg[3] = { b1, b2, b3 };

+  return tud_midi_write(jack_id, msg, 3);

+}

+

+//--------------------------------------------------------------------+

 // Internal Class Driver API

 //--------------------------------------------------------------------+

 void midid_init               (void);

diff --git a/src/common/tusb_types.h b/src/common/tusb_types.h
index 34ad26f15..fd6e435e6 100644
--- a/src/common/tusb_types.h
+++ b/src/common/tusb_types.h
@@ -72,18 +72,24 @@ typedef enum
 /// USB Descriptor Types (section 9.4 table 9-5)

 typedef enum

 {

-  TUSB_DESC_DEVICE                = 0x01 ,

-  TUSB_DESC_CONFIGURATION         = 0x02 ,

-  TUSB_DESC_STRING                = 0x03 ,

-  TUSB_DESC_INTERFACE             = 0x04 ,

-  TUSB_DESC_ENDPOINT              = 0x05 ,

-  TUSB_DESC_DEVICE_QUALIFIER      = 0x06 ,

-  TUSB_DESC_OTHER_SPEED_CONFIG    = 0x07 ,

-  TUSB_DESC_INTERFACE_POWER       = 0x08 ,

-  TUSB_DESC_OTG                   = 0x09 ,

-  TUSB_DESC_DEBUG                 = 0x0A ,

-  TUSB_DESC_INTERFACE_ASSOCIATION = 0x0B ,

-  TUSB_DESC_CLASS_SPECIFIC        = 0x24

+  TUSB_DESC_DEVICE                = 0x01,

+  TUSB_DESC_CONFIGURATION         = 0x02,

+  TUSB_DESC_STRING                = 0x03,

+  TUSB_DESC_INTERFACE             = 0x04,

+  TUSB_DESC_ENDPOINT              = 0x05,

+  TUSB_DESC_DEVICE_QUALIFIER      = 0x06,

+  TUSB_DESC_OTHER_SPEED_CONFIG    = 0x07,

+  TUSB_DESC_INTERFACE_POWER       = 0x08,

+  TUSB_DESC_OTG                   = 0x09,

+  TUSB_DESC_DEBUG                 = 0x0A,

+  TUSB_DESC_INTERFACE_ASSOCIATION = 0x0B,

+

+  // Class Specific Descriptor

+  TUSB_DESC_CS_DEVICE             = 0x21,

+  TUSB_DESC_CS_CONFIGURATION      = 0x22,

+  TUSB_DESC_CS_STRING             = 0x23,

+  TUSB_DESC_CS_INTERFACE          = 0x24,

+  TUSB_DESC_CS_ENDPOINT           = 0x25,

 }tusb_desc_type_t;

 

 typedef enum

@@ -105,9 +111,9 @@ typedef enum
 

 typedef enum

 {

-  TUSB_REQ_FEATURE_EDPT_HALT = 0,

+  TUSB_REQ_FEATURE_EDPT_HALT     = 0,

   TUSB_REQ_FEATURE_REMOTE_WAKEUP = 1,

-  TUSB_REQ_FEATURE_TEST_MODE = 2

+  TUSB_REQ_FEATURE_TEST_MODE     = 2

 }tusb_request_feature_selector_t;

 

 typedef enum

diff --git a/src/device/dcd.h b/src/device/dcd.h
index 0ed4a77d9..168eb181c 100644
--- a/src/device/dcd.h
+++ b/src/device/dcd.h
@@ -110,9 +110,6 @@ bool dcd_edpt_open        (uint8_t rhport, tusb_desc_endpoint_t const * p_endpoi
 // Submit a transfer, When complete dcd_event_xfer_complete() is invoked to notify the stack

 bool dcd_edpt_xfer        (uint8_t rhport, uint8_t ep_addr, uint8_t * buffer, uint16_t total_bytes);

 

-// Check if endpoint transferring is complete (TODO remove)

-bool dcd_edpt_busy        (uint8_t rhport, uint8_t ep_addr);

-

 // Stall endpoint

 void dcd_edpt_stall       (uint8_t rhport, uint8_t ep_addr);

 

diff --git a/src/device/usbd.h b/src/device/usbd.h
index 47e0e531c..d3a5dce66 100644
--- a/src/device/usbd.h
+++ b/src/device/usbd.h
@@ -111,13 +111,13 @@ TU_ATTR_WEAK void tud_resume_cb(void);
   /* CDC Control Interface */\

   9, TUSB_DESC_INTERFACE, _itfnum, 0, 1, TUSB_CLASS_CDC, CDC_COMM_SUBCLASS_ABSTRACT_CONTROL_MODEL, CDC_COMM_PROTOCOL_ATCOMMAND, _stridx,\

   /* CDC Header */\

-  5, TUSB_DESC_CLASS_SPECIFIC, CDC_FUNC_DESC_HEADER, U16_TO_U8S_LE(0x0120),\

+  5, TUSB_DESC_CS_INTERFACE, CDC_FUNC_DESC_HEADER, U16_TO_U8S_LE(0x0120),\

   /* CDC Call */\

-  5, TUSB_DESC_CLASS_SPECIFIC, CDC_FUNC_DESC_CALL_MANAGEMENT, 0, (_itfnum) + 1,\

+  5, TUSB_DESC_CS_INTERFACE, CDC_FUNC_DESC_CALL_MANAGEMENT, 0, (_itfnum) + 1,\

   /* CDC ACM: support line request */\

-  4, TUSB_DESC_CLASS_SPECIFIC, CDC_FUNC_DESC_ABSTRACT_CONTROL_MANAGEMENT, 2,\

+  4, TUSB_DESC_CS_INTERFACE, CDC_FUNC_DESC_ABSTRACT_CONTROL_MANAGEMENT, 2,\

   /* CDC Union */\

-  5, TUSB_DESC_CLASS_SPECIFIC, CDC_FUNC_DESC_UNION, _itfnum, (_itfnum) + 1,\

+  5, TUSB_DESC_CS_INTERFACE, CDC_FUNC_DESC_UNION, _itfnum, (_itfnum) + 1,\

   /* Endpoint Notification */\

   7, TUSB_DESC_ENDPOINT, _ep_notif, TUSB_XFER_INTERRUPT, U16_TO_U8S_LE(_ep_notif_size), 16,\

   /* CDC Data Interface */\

@@ -171,6 +171,43 @@ TU_ATTR_WEAK void tud_resume_cb(void);
   /* Endpoint Out */\

   7, TUSB_DESC_ENDPOINT, _epout, TUSB_XFER_INTERRUPT, U16_TO_U8S_LE(_epsize), _ep_interval

 

+//------------- MIDI -------------//

+

+// Length of template descriptor (96 bytes)

+#define TUD_MIDI_DESC_LEN (8 + 9 + 9 + 9 + 7 + 6 + 6 + 9 + 9 + 7 + 5 + 7 + 5)

+

+// MIDI simple descriptor

+// - 1 Embedded Jack In connected to 1 External Jack Out

+// - 1 Embedded Jack out connected to 1 External Jack In

+#define TUD_MIDI_DESCRIPTOR(_itfnum, _stridx, _epin, _epout, _epsize) \

+  /* Interface Associate */\

+  8, TUSB_DESC_INTERFACE_ASSOCIATION, _itfnum, 2, TUSB_CLASS_AUDIO, 0x00, AUDIO_PROTOCOL_V1, 0,\

+  /* Audio Control (AC) Interface */\

+  9, TUSB_DESC_INTERFACE, _itfnum, 0, 0, TUSB_CLASS_AUDIO, AUDIO_SUBCLASS_CONTROL, AUDIO_PROTOCOL_V1, _stridx,\

+  /* AC Header */\

+  9, TUSB_DESC_CS_INTERFACE, AUDIO_CS_INTERFACE_HEADER, U16_TO_U8S_LE(0x0100), U16_TO_U8S_LE(0x0009), 1, _itfnum+1,\

+  /* MIDI Streaming (MS) Interface */\

+  9, TUSB_DESC_INTERFACE, _itfnum+1, 0, 2, TUSB_CLASS_AUDIO, AUDIO_SUBCLASS_MIDI_STREAMING, AUDIO_PROTOCOL_V1, 0,\

+  /* MS Header */\

+  7, TUSB_DESC_CS_INTERFACE, MIDI_CS_INTERFACE_HEADER, U16_TO_U8S_LE(0x0100), U16_TO_U8S_LE(0x0025),\

+  /* MS In Jack (Embedded) */\

+  6, TUSB_DESC_CS_INTERFACE, MIDI_CS_INTERFACE_IN_JACK, MIDI_JACK_EMBEDDED, 1, 0,\

+  /* MS In Jack (External) */\

+  6, TUSB_DESC_CS_INTERFACE, MIDI_CS_INTERFACE_IN_JACK, MIDI_JACK_EXTERNAL, 2, 0,\

+  /* MS Out Jack (Embedded), connected to In Jack External */\

+  9, TUSB_DESC_CS_INTERFACE, MIDI_CS_INTERFACE_OUT_JACK, MIDI_JACK_EMBEDDED, 3, 1, 2, 1, 0,\

+  /* MS Out Jack (External), connected to In Jack Embedded */\

+  9, TUSB_DESC_CS_INTERFACE, MIDI_CS_INTERFACE_OUT_JACK, MIDI_JACK_EXTERNAL, 4, 1, 1, 1, 0,\

+  /* Endpoint Out */\

+  7, TUSB_DESC_ENDPOINT, _epout, TUSB_XFER_BULK, U16_TO_U8S_LE(_epsize), 0,\

+  /* MS Endpoint (connected to embedded jack in) */\

+  5, TUSB_DESC_CS_ENDPOINT, MIDI_CS_ENDPOINT_GENERAL, 1, 1,\

+  /* Endpoint In */\

+  7, TUSB_DESC_ENDPOINT, _epin, TUSB_XFER_BULK, U16_TO_U8S_LE(_epsize), 0,\

+  /* MS Endpoint (connected to embedded jack out) */\

+  5, TUSB_DESC_CS_ENDPOINT, MIDI_CS_ENDPOINT_GENERAL, 1, 3

+

+

 #ifdef __cplusplus

  }

 #endif

diff --git a/src/portable/microchip/samd21/dcd_samd21.c b/src/portable/microchip/samd21/dcd_samd21.c
index fedfa2ec9..7f3c34959 100644
--- a/src/portable/microchip/samd21/dcd_samd21.c
+++ b/src/portable/microchip/samd21/dcd_samd21.c
@@ -229,22 +229,6 @@ void dcd_edpt_clear_stall (uint8_t rhport, uint8_t ep_addr)
   }
 }
 
-bool dcd_edpt_busy (uint8_t rhport, uint8_t ep_addr)
-{
-  (void) rhport;
-
-  // USBD shouldn't check control endpoint state
-  if ( 0 == ep_addr ) return false;
-
-  uint8_t const epnum = tu_edpt_number(ep_addr);
-  UsbDeviceEndpoint* ep = &USB->DEVICE.DeviceEndpoint[epnum];
-
-  if (tu_edpt_dir(ep_addr) == TUSB_DIR_IN) {
-    return ep->EPINTFLAG.bit.TRCPT1 == 0 && ep->EPSTATUS.bit.BK1RDY == 1;
-  }
-  return ep->EPINTFLAG.bit.TRCPT0 == 0 && ep->EPSTATUS.bit.BK0RDY == 1;
-}
-
 /*------------------------------------------------------------------*/
 
 static bool maybe_handle_setup_packet(void) {
diff --git a/src/portable/microchip/samd51/dcd_samd51.c b/src/portable/microchip/samd51/dcd_samd51.c
index a43609b9e..f2aff857c 100644
--- a/src/portable/microchip/samd51/dcd_samd51.c
+++ b/src/portable/microchip/samd51/dcd_samd51.c
@@ -233,22 +233,6 @@ void dcd_edpt_clear_stall (uint8_t rhport, uint8_t ep_addr)
   }
 }
 
-bool dcd_edpt_busy (uint8_t rhport, uint8_t ep_addr)
-{
-  (void) rhport;
-
-  // USBD shouldn't check control endpoint state
-  if ( 0 == ep_addr ) return false;
-
-  uint8_t const epnum = tu_edpt_number(ep_addr);
-  UsbDeviceEndpoint* ep = &USB->DEVICE.DeviceEndpoint[epnum];
-
-  if (tu_edpt_dir(ep_addr) == TUSB_DIR_IN) {
-    return ep->EPINTFLAG.bit.TRCPT1 == 0 && ep->EPSTATUS.bit.BK1RDY == 1;
-  }
-  return ep->EPINTFLAG.bit.TRCPT0 == 0 && ep->EPSTATUS.bit.BK0RDY == 1;
-}
-
 /*------------------------------------------------------------------*/
 
 static bool maybe_handle_setup_packet(void) {
diff --git a/src/portable/nordic/nrf5x/dcd_nrf5x.c b/src/portable/nordic/nrf5x/dcd_nrf5x.c
index 37b5459f6..093dcfd78 100644
--- a/src/portable/nordic/nrf5x/dcd_nrf5x.c
+++ b/src/portable/nordic/nrf5x/dcd_nrf5x.c
@@ -332,21 +332,6 @@ void dcd_edpt_clear_stall (uint8_t rhport, uint8_t ep_addr)
   }
 }
 
-bool dcd_edpt_busy (uint8_t rhport, uint8_t ep_addr)
-{
-  (void) rhport;
-
-  // USBD shouldn't check control endpoint state
-  if ( 0 == tu_edpt_number(ep_addr) ) return false;
-
-  uint8_t const epnum = tu_edpt_number(ep_addr);
-  uint8_t const dir   = tu_edpt_dir(ep_addr);
-
-  xfer_td_t* xfer = get_td(epnum, dir);
-
-  return xfer->actual_len < xfer->total_len;
-}
-
 /*------------------------------------------------------------------*/
 /* Interrupt Handler
  *------------------------------------------------------------------*/
diff --git a/src/portable/nxp/lpc11_13_15/dcd_lpc11_13_15.c b/src/portable/nxp/lpc11_13_15/dcd_lpc11_13_15.c
index 0dab2caf7..39c365d87 100644
--- a/src/portable/nxp/lpc11_13_15/dcd_lpc11_13_15.c
+++ b/src/portable/nxp/lpc11_13_15/dcd_lpc11_13_15.c
@@ -218,14 +218,6 @@ bool dcd_edpt_open(uint8_t rhport, tusb_desc_endpoint_t const * p_endpoint_desc)
   return true;
 }
 
-bool dcd_edpt_busy(uint8_t rhport, uint8_t ep_addr)
-{
-  (void) rhport;
-
-  uint8_t const ep_id = ep_addr2id(ep_addr);
-  return _dcd.ep[ep_id][0].active;
-}
-
 static void prepare_ep_xfer(uint8_t ep_id, uint16_t buf_offset, uint16_t total_bytes)
 {
   uint16_t const nbytes = tu_min16(total_bytes, DMA_NBYTES_MAX);
diff --git a/src/portable/nxp/lpc17_40/dcd_lpc17_40.c b/src/portable/nxp/lpc17_40/dcd_lpc17_40.c
index cdc4d58db..2b49f52e9 100644
--- a/src/portable/nxp/lpc17_40/dcd_lpc17_40.c
+++ b/src/portable/nxp/lpc17_40/dcd_lpc17_40.c
@@ -316,14 +316,6 @@ bool dcd_edpt_open(uint8_t rhport, tusb_desc_endpoint_t const * p_endpoint_desc)
   return true;
 }
 
-bool dcd_edpt_busy(uint8_t rhport, uint8_t ep_addr)
-{
-  (void) rhport;
-
-  uint8_t ep_id = ep_addr2idx( ep_addr );
-  return (_dcd.udca[ep_id] != NULL && !_dcd.udca[ep_id]->retired);
-}
-
 void dcd_edpt_stall(uint8_t rhport, uint8_t ep_addr)
 {
   (void) rhport;
diff --git a/src/portable/nxp/lpc18_43/dcd_lpc18_43.c b/src/portable/nxp/lpc18_43/dcd_lpc18_43.c
index 049624d92..519e0dcc6 100644
--- a/src/portable/nxp/lpc18_43/dcd_lpc18_43.c
+++ b/src/portable/nxp/lpc18_43/dcd_lpc18_43.c
@@ -240,18 +240,6 @@ bool dcd_edpt_open(uint8_t rhport, tusb_desc_endpoint_t const * p_endpoint_desc)
   return true;
 }
 
-bool dcd_edpt_busy(uint8_t rhport, uint8_t ep_addr)
-{
-  uint8_t const epnum  = tu_edpt_number(ep_addr);
-  uint8_t const dir    = tu_edpt_dir(ep_addr);
-  uint8_t const ep_idx = 2*epnum + dir;
-
-  dcd_qtd_t * p_qtd = &dcd_data_ptr[rhport]->qtd[ep_idx];
-
-  return p_qtd->active;
-//  return !p_qhd->qtd_overlay.halted && p_qhd->qtd_overlay.active;
-}
-
 bool dcd_edpt_xfer(uint8_t rhport, uint8_t ep_addr, uint8_t * buffer, uint16_t total_bytes)
 {
   uint8_t const epnum = tu_edpt_number(ep_addr);
diff --git a/src/portable/st/stm32f3/dcd_stm32f3.c b/src/portable/st/stm32f3/dcd_stm32f3.c
index 648ff0e14..7339863be 100644
--- a/src/portable/st/stm32f3/dcd_stm32f3.c
+++ b/src/portable/st/stm32f3/dcd_stm32f3.c
@@ -67,15 +67,19 @@ bool dcd_edpt_open (uint8_t rhport, tusb_desc_endpoint_t const * p_endpoint_desc
 {
   return false;
 }
+
 bool dcd_edpt_xfer (uint8_t rhport, uint8_t ep_addr, uint8_t * buffer, uint16_t total_bytes)
-{ return false;}
-bool dcd_edpt_busy (uint8_t rhport, uint8_t ep_addr)
-{ return false;}
+{
+  return false;
+}
 
 void dcd_edpt_stall (uint8_t rhport, uint8_t ep_addr)
-{}
+{
+}
+
 void dcd_edpt_clear_stall (uint8_t rhport, uint8_t ep_addr)
-{}
+{
+}
 
 #endif
 
diff --git a/src/portable/st/stm32f4/dcd_stm32f4.c b/src/portable/st/stm32f4/dcd_stm32f4.c
index 996950ab0..3cb502be9 100644
--- a/src/portable/st/stm32f4/dcd_stm32f4.c
+++ b/src/portable/st/stm32f4/dcd_stm32f4.c
@@ -397,32 +397,6 @@ void dcd_edpt_clear_stall (uint8_t rhport, uint8_t ep_addr)
   }
 }
 
-bool dcd_edpt_busy (uint8_t rhport, uint8_t ep_addr)
-{
-  (void) rhport;
-  USB_OTG_OUTEndpointTypeDef * out_ep = OUT_EP_BASE;
-  USB_OTG_INEndpointTypeDef * in_ep = IN_EP_BASE;
-
-  // USBD shouldn't check control endpoint state
-  if ( 0 == ep_addr ) return false;
-
-  uint8_t const epnum = tu_edpt_number(ep_addr);
-
-  bool enabled = false;
-  bool xferring = true;
-
-  if (tu_edpt_dir(ep_addr) == TUSB_DIR_IN) {
-    enabled = (in_ep[epnum].DIEPCTL & USB_OTG_DIEPCTL_EPENA_Msk);
-    xferring = (in_ep[epnum].DIEPTSIZ & USB_OTG_DIEPTSIZ_PKTCNT_Msk);
-  } else {
-    enabled = (out_ep[epnum].DOEPCTL & USB_OTG_DOEPCTL_EPENA_Msk);
-    xferring = (out_ep[epnum].DOEPTSIZ & USB_OTG_DOEPTSIZ_PKTCNT_Msk);
-  }
-
-  // TODO: Also check that endpoint is active (not just enabled)?
-  return (enabled && xferring);
-}
-
 /*------------------------------------------------------------------*/
 
 // TODO: Split into "receive on endpoint 0" and "receive generic"; endpoint 0's
diff --git a/tools/build_all.py b/tools/build_all.py
index 4b0cf9820..93bdef4c1 100644
--- a/tools/build_all.py
+++ b/tools/build_all.py
@@ -12,7 +12,7 @@ success_count = 0
 fail_count = 0
 exit_status = 0
 
-all_device_example = ["cdc_msc_hid", "msc_dual_lun", "hid_generic_inout"]
+all_device_example = ["cdc_msc_hid", "hid_generic_inout", "midi_test", "msc_dual_lun"]
 
 all_boards = []
 for entry in os.scandir("hw/bsp"):