Merge pull request #30 from tannewt/midi

Add MIDI support

15 files changed, 1136 insertions, 1 deletions

diff --git a/.gitmodules b/.gitmodules
index c0dd4dd1d..2d9a88914 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -4,3 +4,6 @@
 [submodule "hw/mcu/microchip/samd/asf4"]
 	path = hw/mcu/microchip/samd/asf4
 	url = https://github.com/adafruit/asf4.git
+[submodule "tests/vendor/unity"]
+	path = tests/vendor/unity
+	url = https://github.com/ThrowTheSwitch/Unity.git
diff --git a/.travis.yml b/.travis.yml
index 1d804dd85..90e8801da 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -19,3 +19,4 @@ before_script:
 script:
   - make -j2 -C examples/device/cdc_msc_hid BOARD=metro_m0_express
   - make -j2 -C examples/device/cdc_msc_hid BOARD=metro_m4_express
+  - cd tests/common && make
diff --git a/examples/device/cdc_msc_hid/src/tusb_config.h b/examples/device/cdc_msc_hid/src/tusb_config.h
index 2ff49aaf7..3f748c3f0 100644
--- a/examples/device/cdc_msc_hid/src/tusb_config.h
+++ b/examples/device/cdc_msc_hid/src/tusb_config.h
@@ -109,6 +109,7 @@
 //------------- CLASS -------------//
 #define CFG_TUD_CDC                 1
 #define CFG_TUD_MSC                 1
+#define CFG_TUD_MIDI                0
 #define CFG_TUD_CUSTOM_CLASS        0
 
 #define CFG_TUD_HID                 0
diff --git a/src/class/audio/audio.h b/src/class/audio/audio.h
new file mode 100644
index 000000000..1ea3f1166
--- /dev/null
+++ b/src/class/audio/audio.h
@@ -0,0 +1,78 @@
+/**************************************************************************/

+/*!

+    @file     cdc.h

+    @author   hathach (tinyusb.org)

+

+    @section LICENSE

+

+    Software License Agreement (BSD License)

+

+    Copyright (c) 2013, hathach (tinyusb.org)

+    All rights reserved.

+

+    Redistribution and use in source and binary forms, with or without

+    modification, are permitted provided that the following conditions are met:

+    1. Redistributions of source code must retain the above copyright

+    notice, this list of conditions and the following disclaimer.

+    2. Redistributions in binary form must reproduce the above copyright

+    notice, this list of conditions and the following disclaimer in the

+    documentation and/or other materials provided with the distribution.

+    3. Neither the name of the copyright holders nor the

+    names of its contributors may be used to endorse or promote products

+    derived from this software without specific prior written permission.

+

+    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ''AS IS'' AND ANY

+    EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED

+    WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE

+    DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE FOR ANY

+    DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES

+    INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;

+    LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION HOWEVER CAUSED AND

+    ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

+    INCLUDING NEGLIGENCE OR OTHERWISE ARISING IN ANY WAY OUT OF THE USE OF THIS

+    SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

+

+    This file is part of the tinyusb stack.

+*/

+/**************************************************************************/

+

+/** \ingroup group_class

+ *  \defgroup ClassDriver_Audio Audio

+ *            Currently only MIDI subclass is supported

+ *  @{ */

+

+#ifndef _TUSB_CDC_H__

+#define _TUSB_CDC_H__

+

+#include "common/tusb_common.h"

+

+#ifdef __cplusplus

+ extern "C" {

+#endif

+

+/// 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_type_t;

+

+/// Audio Protocol Codes

+typedef enum

+{

+  AUDIO_PROTOCOL_V1                   = 0x00, ///< Version 1.0

+  AUDIO_PROTOCOL_V2                   = 0x20, ///< Version 2.0

+  AUDIO_PROTOCOL_V3                   = 0x30, ///< Version 3.0

+} audio_protocol_type_t;

+

+

+/** @} */

+

+#ifdef __cplusplus

+ }

+#endif

+

+#endif

+

+/** @} */

diff --git a/src/class/midi/midi.h b/src/class/midi/midi.h
new file mode 100644
index 000000000..21c43be20
--- /dev/null
+++ b/src/class/midi/midi.h
@@ -0,0 +1,84 @@
+/**************************************************************************/

+/*!

+    @file     cdc.h

+    @author   hathach (tinyusb.org)

+

+    @section LICENSE

+

+    Software License Agreement (BSD License)

+

+    Copyright (c) 2013, hathach (tinyusb.org)

+    All rights reserved.

+

+    Redistribution and use in source and binary forms, with or without

+    modification, are permitted provided that the following conditions are met:

+    1. Redistributions of source code must retain the above copyright

+    notice, this list of conditions and the following disclaimer.

+    2. Redistributions in binary form must reproduce the above copyright

+    notice, this list of conditions and the following disclaimer in the

+    documentation and/or other materials provided with the distribution.

+    3. Neither the name of the copyright holders nor the

+    names of its contributors may be used to endorse or promote products

+    derived from this software without specific prior written permission.

+

+    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ''AS IS'' AND ANY

+    EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED

+    WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE

+    DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE FOR ANY

+    DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES

+    INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;

+    LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION HOWEVER CAUSED AND

+    ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

+    INCLUDING NEGLIGENCE OR OTHERWISE ARISING IN ANY WAY OUT OF THE USE OF THIS

+    SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

+

+    This file is part of the tinyusb stack.

+*/

+/**************************************************************************/

+

+/** \ingroup group_class

+ *  \defgroup ClassDriver_CDC Communication Device Class (CDC)

+ *            Currently only Abstract Control Model subclass is supported

+ *  @{ */

+

+#ifndef _TUSB_MIDI_H__

+#define _TUSB_MIDI_H__

+

+#include "common/tusb_common.h"

+

+#ifdef __cplusplus

+ extern "C" {

+#endif

+

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

+// FUNCTIONAL DESCRIPTOR (COMMUNICATION INTERFACE)

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

+/// Header Functional Descriptor (Communication Interface)

+typedef struct 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_

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

+  uint16_t wTotalLength      ;

+}midi_desc_func_header_t;

+

+/// Union Functional Descriptor (Communication Interface)

+typedef struct 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;

+

+/** @} */

+

+#ifdef __cplusplus

+ }

+#endif

+

+#endif

+

+/** @} */

diff --git a/src/class/midi/midi_device.c b/src/class/midi/midi_device.c
new file mode 100644
index 000000000..9850ce251
--- /dev/null
+++ b/src/class/midi/midi_device.c
@@ -0,0 +1,346 @@
+/**************************************************************************/

+/*!

+    @file     cdc_device.c

+    @author   hathach (tinyusb.org)

+

+    @section LICENSE

+

+    Software License Agreement (BSD License)

+

+    Copyright (c) 2013, hathach (tinyusb.org)

+    All rights reserved.

+

+    Redistribution and use in source and binary forms, with or without

+    modification, are permitted provided that the following conditions are met:

+    1. Redistributions of source code must retain the above copyright

+    notice, this list of conditions and the following disclaimer.

+    2. Redistributions in binary form must reproduce the above copyright

+    notice, this list of conditions and the following disclaimer in the

+    documentation and/or other materials provided with the distribution.

+    3. Neither the name of the copyright holders nor the

+    names of its contributors may be used to endorse or promote products

+    derived from this software without specific prior written permission.

+

+    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ''AS IS'' AND ANY

+    EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED

+    WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE

+    DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE FOR ANY

+    DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES

+    (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;

+    LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND

+    ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

+    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS

+    SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

+

+    This file is part of the tinyusb stack.

+*/

+/**************************************************************************/

+

+#include "tusb_option.h"

+

+#if (TUSB_OPT_DEVICE_ENABLED && CFG_TUD_MIDI)

+

+#define _TINY_USB_SOURCE_FILE_

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

+// INCLUDE

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

+#include "midi_device.h"

+#include "class/audio/audio.h"

+#include "common/tusb_txbuf.h"

+#include "device/usbd_pvt.h"

+

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

+// MACRO CONSTANT TYPEDEF

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

+typedef struct

+{

+  uint8_t itf_num;

+  uint8_t ep_in;

+  uint8_t ep_out;

+

+  // FIFO

+  tu_fifo_t rx_ff;

+  uint8_t rx_ff_buf[CFG_TUD_MIDI_RX_BUFSIZE];

+  osal_mutex_def_t rx_ff_mutex;

+

+  #if CFG_TUD_MIDI_TX_BUFSIZE % CFG_TUD_MIDI_EPSIZE != 0

+  #error "TX buffer size must be multiple of endpoint size."

+  #endif

+

+  // This is a ring buffer that aligns to word boundaries so that it can be transferred directly to

+  // the USB peripheral. There are three states to the data: free, transmitting and pending.

+  CFG_TUSB_MEM_ALIGN uint8_t raw_tx_buffer[CFG_TUD_MIDI_TX_BUFSIZE];

+  tu_txbuf_t txbuf;

+

+  // We need to pack messages into words before queueing their transmission so buffer across write

+  // calls.

+  uint8_t message_buffer[4];

+  uint8_t message_buffer_length;

+  uint8_t message_target_length;

+

+  // Endpoint Transfer buffer

+  CFG_TUSB_MEM_ALIGN uint8_t epout_buf[CFG_TUD_MIDI_EPSIZE];

+

+} midid_interface_t;

+

+#define ITF_MEM_RESET_SIZE   offsetof(midid_interface_t, rx_ff)

+

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

+// INTERNAL OBJECT & FUNCTION DECLARATION

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

+CFG_TUSB_ATTR_USBRAM midid_interface_t _midid_itf[CFG_TUD_MIDI];

+

+bool tud_midi_n_connected(uint8_t itf) {

+  midid_interface_t* midi = &_midid_itf[itf];

+  return midi->itf_num != 0;

+}

+

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

+// READ API

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

+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);

+}

+

+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;

+  }

+

+  for(uint32_t i=0; i<bufsize; i += 4) {

+    uint8_t header = buffer[i];

+    // uint8_t cable_number = (header & 0xf0) >> 4;

+    uint8_t code_index = header & 0x0f;

+    // We always copy over the first byte.

+    uint8_t count = 1;

+    // Ignore subsequent bytes based on the code.

+    if (code_index != 0x5 && code_index != 0xf) {

+      count = 2;

+      if (code_index != 0x2 && code_index != 0x6 && code_index != 0xc && code_index != 0xd) {

+        count = 3;

+      }

+    }

+    tu_fifo_write_n(&midi->rx_ff, &buffer[i + 1], count);

+  }

+}

+

+

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

+// WRITE API

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

+

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

+{

+  midid_interface_t* midi = &_midid_itf[itf];

+  if (midi->itf_num == 0) {

+    return 0;

+  }

+

+  uint32_t i = 0;

+  while (i < bufsize) {

+    uint8_t data = buffer[i];

+    if (midi->message_buffer_length == 0) {

+        uint8_t msg = data >> 4;

+        midi->message_buffer[1] = data;

+        midi->message_buffer_length = 2;

+        // Check to see if we're still in a SysEx transmit.

+        if (midi->message_buffer[0] == 0x4) {

+            if (data == 0xf7) {

+                midi->message_buffer[0] = 0x5;

+            } else {

+                midi->message_buffer_length = 4;

+            }

+        } else if ((msg >= 0x8 && msg <= 0xB) || msg == 0xE) {

+            midi->message_buffer[0] = jack_id << 4 | msg;

+            midi->message_target_length = 4;

+        } else if (msg == 0xf) {

+            if (data == 0xf0) {

+                midi->message_buffer[0] = 0x4;

+                midi->message_target_length = 4;

+            } else if (data == 0xf1 || data == 0xf3) {

+                midi->message_buffer[0] = 0x2;

+                midi->message_target_length = 3;

+            } else if (data == 0xf2) {

+                midi->message_buffer[0] = 0x3;

+                midi->message_target_length = 4;

+            } else {

+                midi->message_buffer[0] = 0x5;

+                midi->message_target_length = 2;

+            }

+        } else {

+            // Pack individual bytes if we don't support packing them into words.

+            midi->message_buffer[0] = jack_id << 4 | 0xf;

+            midi->message_buffer[2] = 0;

+            midi->message_buffer[3] = 0;

+            midi->message_buffer_length = 2;

+            midi->message_target_length = 2;

+        }

+    } else {

+        midi->message_buffer[midi->message_buffer_length] = data;

+        midi->message_buffer_length += 1;

+        // See if this byte ends a SysEx.

+        if (midi->message_buffer[0] == 0x4 && data == 0xf7) {

+            midi->message_buffer[0] = 0x4 + (midi->message_buffer_length - 1);

+            midi->message_target_length = midi->message_buffer_length;

+        }

+    }

+

+    if (midi->message_buffer_length == midi->message_target_length) {

+        tu_txbuf_write_n(&midi->txbuf, midi->message_buffer, 4);

+        midi->message_buffer_length = 0;

+    }

+    i++;

+  }

+

+  return i;

+}

+

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

+// USBD Driver API

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

+void midid_init(void)

+{

+  tu_memclr(_midid_itf, sizeof(_midid_itf));

+

+  for(uint8_t i=0; i<CFG_TUD_MIDI; i++)

+  {

+    midid_interface_t* midi = &_midid_itf[i];

+

+    // config fifo

+    tu_fifo_config(&midi->rx_ff, midi->rx_ff_buf, CFG_TUD_MIDI_RX_BUFSIZE, 1, true);

+    #if CFG_FIFO_MUTEX

+    tu_fifo_config_mutex(&midi->rx_ff, osal_mutex_create(&midi->rx_ff_mutex));

+    #endif

+

+    tu_txbuf_config(&midi->txbuf, midi->raw_tx_buffer, CFG_TUD_MIDI_TX_BUFSIZE, dcd_edpt_xfer);

+  }

+}

+

+void midid_reset(uint8_t rhport)

+{

+  (void) rhport;

+

+  for(uint8_t i=0; i<CFG_TUD_MIDI; i++)

+  {

+    midid_interface_t* midi = &_midid_itf[i];

+    tu_memclr(midi, ITF_MEM_RESET_SIZE);

+    tu_fifo_clear(&midi->rx_ff);

+    tu_txbuf_clear(&midi->txbuf);

+  }

+}

+

+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) {

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

+    (*p_length) = sizeof(tusb_desc_interface_t);

+

+    // Skip over the class specific descriptor.

+    (*p_length) += p_desc[DESC_OFFSET_LEN];

+    p_desc = tu_desc_next(p_desc);

+    return true;

+  }

+

+  if ( AUDIO_SUBCLASS_MIDI_STREAMING != p_interface_desc->bInterfaceSubClass ||

+       p_interface_desc->bInterfaceProtocol != AUDIO_PROTOCOL_V1 ) {

+    return false;

+  }

+

+  // Find available interface

+  midid_interface_t * p_midi = NULL;

+  for(uint8_t i=0; i<CFG_TUD_MIDI; i++)

+  {

+    if ( _midid_itf[i].ep_in == 0 && _midid_itf[i].ep_out == 0 )

+    {

+      p_midi = &_midid_itf[i];

+      break;

+    }

+  }

+

+  p_midi->itf_num  = p_interface_desc->bInterfaceNumber;

+

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

+  (*p_length) = sizeof(tusb_desc_interface_t);

+

+  uint8_t found_endpoints = 0;

+  while (found_endpoints < p_interface_desc->bNumEndpoints) {

+    if ( TUSB_DESC_ENDPOINT == p_desc[DESC_OFFSET_TYPE])

+    {

+        TU_ASSERT( dcd_edpt_open(rhport, (tusb_desc_endpoint_t const *) p_desc), false);

+        uint8_t ep_addr = ((tusb_desc_endpoint_t const *) p_desc)->bEndpointAddress;

+        if (tu_edpt_dir(ep_addr) == TUSB_DIR_IN) {

+            p_midi->ep_in = ep_addr;

+            tu_txbuf_set_ep_addr(&p_midi->txbuf, ep_addr);

+        } else {

+            p_midi->ep_out = ep_addr;

+        }

+

+        (*p_length) += p_desc[DESC_OFFSET_LEN];

+        p_desc = tu_desc_next(p_desc);

+        found_endpoints += 1;

+    }

+    (*p_length) += p_desc[DESC_OFFSET_LEN];

+    p_desc = tu_desc_next(p_desc);

+  }

+

+  // Prepare for incoming data

+  TU_ASSERT( dcd_edpt_xfer(rhport, p_midi->ep_out, p_midi->epout_buf, CFG_TUD_MIDI_EPSIZE), false);

+

+  return true;

+}

+

+bool midid_control_request_complete(uint8_t rhport, tusb_control_request_t const * p_request)

+{

+  return false;

+}

+

+bool midid_control_request(uint8_t rhport, tusb_control_request_t const * p_request)

+{

+  //------------- Class Specific Request -------------//

+  if (p_request->bmRequestType_bit.type != TUSB_REQ_TYPE_CLASS) return false;

+

+  return false;

+}

+

+bool midid_xfer_cb(uint8_t rhport, uint8_t edpt_addr, xfer_result_t result, uint32_t xferred_bytes)

+{

+  // TODO Support multiple interfaces

+  uint8_t const itf = 0;

+  midid_interface_t* p_midi = &_midid_itf[itf];

+

+  // receive new data

+  if ( edpt_addr == p_midi->ep_out )

+  {

+    midi_rx_done_cb(p_midi, p_midi->epout_buf, xferred_bytes);

+

+    // prepare for next

+    TU_ASSERT( dcd_edpt_xfer(rhport, p_midi->ep_out, p_midi->epout_buf, CFG_TUD_MIDI_EPSIZE), false );

+  } else if ( edpt_addr == p_midi->ep_in ) {

+    tu_txbuf_transmit_done_cb(&p_midi->txbuf, xferred_bytes);

+  }

+

+  // nothing to do with in and notif endpoint

+

+  return TUSB_ERROR_NONE;

+}

+

+#endif

diff --git a/src/class/midi/midi_device.h b/src/class/midi/midi_device.h
new file mode 100644
index 000000000..70030f2ce
--- /dev/null
+++ b/src/class/midi/midi_device.h
@@ -0,0 +1,120 @@
+/**************************************************************************/

+/*!

+    @file     midi_device.h

+    @author   hathach (tinyusb.org)

+

+    @section LICENSE

+

+    Software License Agreement (BSD License)

+

+    Copyright (c) 2013, hathach (tinyusb.org)

+    All rights reserved.

+

+    Redistribution and use in source and binary forms, with or without

+    modification, are permitted provided that the following conditions are met:

+    1. Redistributions of source code must retain the above copyright

+    notice, this list of conditions and the following disclaimer.

+    2. Redistributions in binary form must reproduce the above copyright

+    notice, this list of conditions and the following disclaimer in the

+    documentation and/or other materials provided with the distribution.

+    3. Neither the name of the copyright holders nor the

+    names of its contributors may be used to endorse or promote products

+    derived from this software without specific prior written permission.

+

+    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ''AS IS'' AND ANY

+    EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED

+    WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE

+    DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE FOR ANY

+    DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES

+    (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;

+    LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND

+    ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

+    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS

+    SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

+

+    This file is part of the tinyusb stack.

+*/

+/**************************************************************************/

+

+#ifndef _TUSB_MIDI_DEVICE_H_

+#define _TUSB_MIDI_DEVICE_H_

+

+#include "common/tusb_common.h"

+#include "device/usbd.h"

+#include "class/audio/audio.h"

+

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

+// Class Driver Configuration

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

+#ifndef CFG_TUD_MIDI_EPSIZE

+#define CFG_TUD_MIDI_EPSIZE 64

+#endif

+

+

+#ifdef __cplusplus

+ extern "C" {

+#endif

+

+/** \addtogroup MIDI_Serial Serial

+ *  @{

+ *  \defgroup   MIDI_Serial_Device Device

+ *  @{ */

+

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

+// APPLICATION API (Multiple Interfaces)

+// CFG_TUD_MIDI > 1

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

+bool     tud_midi_n_connected       (uint8_t itf);

+

+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);

+

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

+// 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);            }

+

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

+// APPLICATION CALLBACK API (WEAK is optional)

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

+ATTR_WEAK void tud_midi_rx_cb(uint8_t itf);

+

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

+// USBD-CLASS DRIVER API

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

+#ifdef _TINY_USB_SOURCE_FILE_

+

+void         midid_init               (void);

+bool midid_open               (uint8_t rhport, tusb_desc_interface_t const * p_interface_desc, uint16_t *p_length);

+bool midid_control_request (uint8_t rhport, tusb_control_request_t const * p_request);

+bool midid_control_request_complete (uint8_t rhport, tusb_control_request_t const * p_request);

+bool midid_xfer_cb            (uint8_t rhport, uint8_t edpt_addr, xfer_result_t result, uint32_t xferred_bytes);

+void         midid_reset              (uint8_t rhport);

+

+#endif

+

+#ifdef __cplusplus

+ }

+#endif

+

+#endif /* _TUSB_MIDI_DEVICE_H_ */

+

+/** @} */

+/** @} */

diff --git a/src/common/tusb_txbuf.c b/src/common/tusb_txbuf.c
new file mode 100644
index 000000000..de1bbe49b
--- /dev/null
+++ b/src/common/tusb_txbuf.c
@@ -0,0 +1,159 @@
+/**************************************************************************/

+/*!

+    @file     tusb_txbuf.c

+    @author   Scott Shawcroft

+

+    @section LICENSE

+

+    Software License Agreement (BSD License)

+

+    Copyright (c) 2018, Scott Shawcroft

+    All rights reserved.

+

+    Redistribution and use in source and binary forms, with or without

+    modification, are permitted provided that the following conditions are met:

+    1. Redistributions of source code must retain the above copyright

+    notice, this list of conditions and the following disclaimer.

+    2. Redistributions in binary form must reproduce the above copyright

+    notice, this list of conditions and the following disclaimer in the

+    documentation and/or other materials provided with the distribution.

+    3. Neither the name of the copyright holders nor the

+    names of its contributors may be used to endorse or promote products

+    derived from this software without specific prior written permission.

+

+    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ''AS IS'' AND ANY

+    EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED

+    WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE

+    DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE FOR ANY

+    DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES

+    INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;

+    LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION HOWEVER CAUSED AND

+    ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

+    INCLUDING NEGLIGENCE OR OTHERWISE ARISING IN ANY WAY OUT OF THE USE OF THIS

+    SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

+

+ This file is part of the tinyusb stack.

+ */

+/**************************************************************************/

+#include <stdio.h>

+#include <string.h>

+

+#include "tusb_txbuf.h"

+

+bool tu_txbuf_config(tu_txbuf_t *txbuf, uint8_t* buffer, uint16_t buffer_length, edpt_xfer xfer)

+{

+  txbuf->buffer = (uint8_t*) buffer;

+  txbuf->buf_len = buffer_length;

+  txbuf->first_free = 0;

+  txbuf->pending_count = 0;

+  txbuf->transmitting_count = 0;

+  txbuf->xfer = xfer;

+  txbuf->padding = 0;

+

+  return true;

+}

+

+uint16_t maybe_transmit(tu_txbuf_t* buf) {

+    if (buf->transmitting_count > 0 || buf->pending_count == 0) {

+        return 0;

+    }

+    buf->transmitting_count = buf->pending_count;

+    uint16_t transmit_start_index;

+    uint8_t over_aligned = 0;

+    // The pending zone wraps back to the end so we must do two transfers.

+    if (buf->pending_count > buf->first_free) {

+        buf->transmitting_count -= buf->first_free;

+        transmit_start_index = buf->buf_len - buf->transmitting_count;

+    } else {

+        transmit_start_index = buf->first_free - buf->transmitting_count;

+

+        // We are transmitting up to first free so ensure it's word aligned for the next transmit.

+        over_aligned = buf->first_free % sizeof(uint32_t);

+        buf->padding = sizeof(uint32_t) - over_aligned;

+        if (over_aligned != 0) {

+            buf->first_free = (buf->first_free + buf->padding) % buf->buf_len;

+        }

+    }

+    buf->pending_count -= buf->transmitting_count;

+

+    uint8_t* tx_start = buf->buffer + transmit_start_index;

+    if (!buf->xfer(0, buf->ep_addr, tx_start, buf->transmitting_count)) {

+        return 0;

+    }

+    return buf->transmitting_count;

+}

+

+uint32_t tu_txbuf_transmit_done_cb(tu_txbuf_t* buf, uint32_t bufsize) {

+    buf->transmitting_count -= bufsize;

+

+    return maybe_transmit(buf);

+}

+

+/******************************************************************************/

+/*!

+    @brief This function will write n elements into the array index specified by

+    the write pointer and increment the write index. If the write index

+    exceeds the max buffer size, then it will roll over to zero.

+

+    @param[in]  f

+                Pointer to the FIFO buffer to manipulate

+    @param[in]  p_data

+                The pointer to data to add to the FIFO

+    @param[in]  count

+                Number of element

+    @return Number of written elements

+*/

+/******************************************************************************/

+uint16_t tu_txbuf_write_n(tu_txbuf_t* txbuf, uint8_t const* buffer, uint32_t bufsize) {

+    uint32_t len;

+    int32_t last_free = txbuf->first_free - txbuf->pending_count - txbuf->transmitting_count - txbuf->padding;

+    if (last_free < 0) {

+        last_free += txbuf->buf_len;

+        len = last_free - txbuf->first_free;

+    } else {

+        len = txbuf->buf_len - txbuf->first_free;

+    }

+    if (bufsize < len) {

+        len = bufsize;

+    }

+    memcpy(txbuf->buffer + txbuf->first_free, buffer, len);

+    txbuf->first_free = (txbuf->first_free + len) % txbuf->buf_len;

+    txbuf->pending_count += len;

+    // Try to transmit now while we wrap the rest.

+    maybe_transmit(txbuf);

+    uint32_t remaining_bytes = bufsize - len;

+    if (remaining_bytes > 0 && last_free != txbuf->first_free) {

+        uint32_t second_len = remaining_bytes;

+        if (second_len > (uint32_t) last_free + 1) {

+            second_len = last_free + 1;

+        }

+        memcpy(txbuf->buffer, buffer + len, second_len);

+        txbuf->first_free = (txbuf->first_free + second_len) % txbuf->buf_len;

+        txbuf->pending_count += second_len;

+        len += second_len;

+    }

+

+    return len;

+}

+

+void tu_txbuf_set_ep_addr(tu_txbuf_t* txbuf, uint8_t ep_addr) {

+    txbuf->ep_addr = ep_addr;

+}

+

+/******************************************************************************/

+/*!

+    @brief Clear the txbuf including any currently transmitting data.

+

+    @param[in]  t

+                Pointer to the txbuf to manipulate

+*/

+/******************************************************************************/

+bool tu_txbuf_clear(tu_txbuf_t *txbuf)

+{

+

+  txbuf->first_free = 0;

+  txbuf->pending_count = 0;

+  txbuf->transmitting_count = 0;

+

+  return true;

+}

diff --git a/src/common/tusb_txbuf.h b/src/common/tusb_txbuf.h
new file mode 100644
index 000000000..88d48ecac
--- /dev/null
+++ b/src/common/tusb_txbuf.h
@@ -0,0 +1,83 @@
+/**************************************************************************/

+/*!

+    @file     tusb_txbuf.h

+    @author   Scott Shawcroft

+

+    @section LICENSE

+

+    Software License Agreement (BSD License)

+

+    Copyright (c) 2018, Scott Shawcroft

+    All rights reserved.

+

+    Redistribution and use in source and binary forms, with or without

+    modification, are permitted provided that the following conditions are met:

+    1. Redistributions of source code must retain the above copyright

+    notice, this list of conditions and the following disclaimer.

+    2. Redistributions in binary form must reproduce the above copyright

+    notice, this list of conditions and the following disclaimer in the

+    documentation and/or other materials provided with the distribution.

+    3. Neither the name of the copyright holders nor the

+    names of its contributors may be used to endorse or promote products

+    derived from this software without specific prior written permission.

+

+    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ''AS IS'' AND ANY

+    EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED

+    WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE

+    DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE FOR ANY

+    DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES

+    INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;

+    LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION HOWEVER CAUSED AND

+    ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

+    INCLUDING NEGLIGENCE OR OTHERWISE ARISING IN ANY WAY OUT OF THE USE OF THIS

+    SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

+

+	  This file is part of the tinyusb stack.

+*/

+/**************************************************************************/

+

+/** \ingroup Group_Common

+ * \defgroup group_txbuf txbuf

+ *  @{ */

+

+#ifndef _TUSB_TXBUF_H_

+#define _TUSB_TXBUF_H_

+

+#include <stdint.h>

+#include <stdbool.h>

+

+#ifdef __cplusplus

+ extern "C" {

+#endif

+

+typedef bool (*edpt_xfer) (uint8_t rhport, uint8_t ep_addr, uint8_t* buffer, uint16_t total_bytes);

+

+

+/** \struct tu_txbuf_t

+ * \brief Circular transmit buffer that manages USB transfer memory. It is not threadsafe and is

+ *        only meant for use in the main task.

+ */

+typedef struct

+{

+    uint8_t* buffer    ; ///< buffer pointer

+    uint16_t buf_len;

+    uint16_t first_free;

+    uint16_t pending_count;

+    uint16_t transmitting_count;

+    uint16_t padding;

+    uint8_t ep_addr;

+    edpt_xfer xfer;

+} tu_txbuf_t;

+

+bool tu_txbuf_clear(tu_txbuf_t *f);

+bool tu_txbuf_config(tu_txbuf_t *f, uint8_t* buffer, uint16_t depth, edpt_xfer xfer);

+

+uint16_t tu_txbuf_write_n (tu_txbuf_t* txbuf, uint8_t const * buffer, uint32_t length);

+void tu_txbuf_set_ep_addr(tu_txbuf_t* txbuf, uint8_t ep_addr);

+uint32_t tu_txbuf_transmit_done_cb(tu_txbuf_t* buf, uint32_t bufsize);

+

+#ifdef __cplusplus

+ }

+#endif

+

+#endif /* _TUSB_TXBUF_H_ */

diff --git a/src/device/usbd.c b/src/device/usbd.c
index a3fbfdff9..9c08a7932 100644
--- a/src/device/usbd.c
+++ b/src/device/usbd.c
@@ -128,6 +128,19 @@ static usbd_class_driver_t const usbd_class_drivers[] =
     },

   #endif

 

+  #if CFG_TUD_MIDI

+    {

+        .class_code      = TUSB_CLASS_AUDIO,

+        .init            = midid_init,

+        .open            = midid_open,

+        .control_request = midid_control_request,

+        .control_request_complete = midid_control_request_complete,

+        .xfer_cb         = midid_xfer_cb,

+        .sof             = NULL,

+        .reset           = midid_reset

+    },

+  #endif

+

   #if CFG_TUD_CUSTOM_CLASS

     {

         .class_code      = TUSB_CLASS_VENDOR_SPECIFIC,

diff --git a/src/tusb.h b/src/tusb.h
index 389bf54d4..fb20c5ff7 100644
--- a/src/tusb.h
+++ b/src/tusb.h
@@ -89,6 +89,10 @@
     #include "class/msc/msc_device.h"

   #endif

 

+  #if CFG_TUD_MIDI

+    #include "class/midi/midi_device.h"

+  #endif

+

   #if CFG_TUD_CUSTOM_CLASS

     #include "class/custom/custom_device.h"

   #endif

@@ -128,4 +132,3 @@ static inline void tusb_task(void)
 #endif

 

 #endif /* _TUSB_H_ */

-

diff --git a/tests/common/Makefile b/tests/common/Makefile
new file mode 100644
index 000000000..2810fbae0
--- /dev/null
+++ b/tests/common/Makefile
@@ -0,0 +1,91 @@
+ifeq ($(OS),Windows_NT)
+  ifeq ($(shell uname -s),) # not in a bash-like shell
+	CLEANUP = del /F /Q
+	MKDIR = mkdir
+  else # in a bash-like shell, like msys
+	CLEANUP = rm -f
+	MKDIR = mkdir -p
+  endif
+	TARGET_EXTENSION=.exe
+else
+	CLEANUP = rm -f
+	MKDIR = mkdir -p
+	TARGET_EXTENSION=out
+endif
+
+.PHONY: clean
+.PHONY: test
+
+PATHU = ../vendor/unity/src/
+PATHS = ../../src/
+PATHT = test/
+PATHB = build/
+PATHD = build/depends/
+PATHO = build/objs/
+PATHR = build/results/
+
+BUILD_PATHS = $(PATHB) $(PATHD) $(PATHO) $(PATHR)
+
+SRCT = $(wildcard $(PATHT)*.c)
+
+$(info $(SRCT))
+
+COMPILE=gcc -c
+LINK=gcc
+DEPEND=gcc -MM -MG -MF
+CFLAGS=-I. -I$(PATHU) -I$(PATHS) -DTEST
+
+RESULTS = $(patsubst $(PATHT)test%.c,$(PATHR)test%.txt,$(SRCT) )
+
+PASSED = `grep -s PASS $(PATHR)*.txt`
+FAIL = `grep -s FAIL $(PATHR)*.txt`
+IGNORE = `grep -s IGNORE $(PATHR)*.txt`
+
+test: $(BUILD_PATHS) $(RESULTS)
+	@echo "-----------------------\nIGNORES:\n-----------------------"
+	@echo "$(IGNORE)"
+	@echo "-----------------------\nFAILURES:\n-----------------------"
+	@echo "$(FAIL)"
+	@echo "-----------------------\nPASSED:\n-----------------------"
+	@echo "$(PASSED)"
+	@echo "\nDONE"
+
+$(PATHR)%.txt: $(PATHB)%.$(TARGET_EXTENSION)
+	-./$< > $@ 2>&1
+
+$(PATHB)test_%.$(TARGET_EXTENSION): $(PATHO)test_%.o $(PATHO)tusb_%.o $(PATHU)unity.o #$(PATHD)test%.d
+	$(LINK) -o $@ $^
+
+$(PATHO)%.o:: $(PATHT)%.c
+	$(COMPILE) $(CFLAGS) $< -o $@
+
+$(PATHO)%.o:: $(PATHS)common/%.c
+	$(COMPILE) $(CFLAGS) $< -o $@
+
+$(PATHO)%.o:: $(PATHU)%.c $(PATHU)%.h
+	$(COMPILE) $(CFLAGS) $< -o $@
+
+$(PATHD)%.d:: $(PATHT)%.c
+	$(DEPEND) $@ $<
+
+$(PATHB):
+	$(MKDIR) $(PATHB)
+
+$(PATHD):
+	$(MKDIR) $(PATHD)
+
+$(PATHO):
+	$(MKDIR) $(PATHO)
+
+$(PATHR):
+	$(MKDIR) $(PATHR)
+
+clean:
+	$(CLEANUP) $(PATHO)*.o
+	$(CLEANUP) $(PATHB)*.$(TARGET_EXTENSION)
+	$(CLEANUP) $(PATHR)*.txt
+
+.PRECIOUS: $(PATHB)test%.$(TARGET_EXTENSION)
+.PRECIOUS: $(PATHD)%.d
+.PRECIOUS: $(PATHO)%.o
+.PRECIOUS: $(PATHR)%.txt
diff --git a/tests/common/build/results/test_txbuf.txt b/tests/common/build/results/test_txbuf.txt
new file mode 100644
index 000000000..a763a4717
--- /dev/null
+++ b/tests/common/build/results/test_txbuf.txt
@@ -0,0 +1,8 @@
+test/test_txbuf.c:140:test_normal:PASS
+test/test_txbuf.c:141:test_nearly_full:PASS
+test/test_txbuf.c:142:test_wrap_around:PASS
+test/test_txbuf.c:143:test_wrap_around_too_much:PASS
+
+-----------------------
+4 Tests 0 Failures 0 Ignored 
+OK
diff --git a/tests/common/test/test_txbuf.c b/tests/common/test/test_txbuf.c
new file mode 100644
index 000000000..efa442f04
--- /dev/null
+++ b/tests/common/test/test_txbuf.c
@@ -0,0 +1,145 @@
+/**************************************************************************/
+/*!
+    @file     test_fifo.c
+    @author   Scott Shawcroft
+
+    @section LICENSE
+
+    Software License Agreement (BSD License)
+
+    Copyright (c) 2019, Scott Shawcroft
+    All rights reserved.
+
+    Redistribution and use in source and binary forms, with or without
+    modification, are permitted provided that the following conditions are met:
+    1. Redistributions of source code must retain the above copyright
+    notice, this list of conditions and the following disclaimer.
+    2. Redistributions in binary form must reproduce the above copyright
+    notice, this list of conditions and the following disclaimer in the
+    documentation and/or other materials provided with the distribution.
+    3. Neither the name of the copyright holders nor the
+    names of its contributors may be used to endorse or promote products
+    derived from this software without specific prior written permission.
+
+    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ''AS IS'' AND ANY
+    EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+    WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+    DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE FOR ANY
+    DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+    INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+    LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION HOWEVER CAUSED AND
+    ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+    INCLUDING NEGLIGENCE OR OTHERWISE ARISING IN ANY WAY OUT OF THE USE OF THIS
+    SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+    This file is part of the tinyusb stack.
+*/
+/**************************************************************************/
+
+#include "unity.h"
+#include "common/tusb_txbuf.h"
+
+uint32_t xfer_count = 0;
+uint32_t freshly_transmitted = 0;
+
+bool mock_xfer(uint8_t rhport, uint8_t ep_addr, uint8_t* buffer, uint16_t total_bytes) {
+    TEST_ASSERT_EQUAL_INT_MESSAGE(0, ((size_t) buffer) % 4, "Transferred buffer not word aligned.");
+    xfer_count++;
+    freshly_transmitted += total_bytes;
+    return true;
+}
+
+tu_txbuf_t txbuf;
+__attribute__((aligned(4))) uint8_t buffer[16];
+
+uint8_t data[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16};
+
+void setUp(void) {
+    tu_txbuf_config(&txbuf, buffer, 16, mock_xfer);
+    tu_txbuf_set_ep_addr(&txbuf, 1);
+}
+
+void tearDown(void) {
+    xfer_count = 0;
+    freshly_transmitted = 0;
+}
+
+void xfer_callback(void) {
+    uint32_t previously_transmitted = freshly_transmitted;
+    freshly_transmitted = 0;
+
+    tu_txbuf_transmit_done_cb(&txbuf, previously_transmitted);
+}
+
+// Test that we transfer immediately at the start and that the pointer is rounded to a word.
+void test_normal(void) {
+    uint16_t written = tu_txbuf_write_n(&txbuf, data, 4);
+    TEST_ASSERT_EQUAL_INT(4, written);
+    TEST_ASSERT_EQUAL_INT(1, xfer_count);
+    xfer_callback();
+    TEST_ASSERT_EQUAL_INT(1, xfer_count);
+}
+
+// Test that we only accept the data we have room for.
+void test_nearly_full(void) {
+    uint16_t written = tu_txbuf_write_n(&txbuf, data, 11);
+    TEST_ASSERT_EQUAL_INT(11, written);
+    TEST_ASSERT_EQUAL_INT(1, xfer_count);
+
+    written = tu_txbuf_write_n(&txbuf, data, 11);
+    // We only have space for 4 more bytes because 11 + padding are being written.
+    TEST_ASSERT_EQUAL_INT(4, written);
+
+    // Callback triggers a second write of remaining data.
+    xfer_callback();
+    TEST_ASSERT_EQUAL_INT(2, xfer_count);
+    TEST_ASSERT_EQUAL_INT(4, freshly_transmitted);
+}
+
+// Test that we only accept the data even when we have to wrap around.
+void test_wrap_around(void) {
+    uint16_t written = tu_txbuf_write_n(&txbuf, data, 11);
+    TEST_ASSERT_EQUAL_INT(11, written);
+    TEST_ASSERT_EQUAL_INT(1, xfer_count);
+    xfer_callback();
+    TEST_ASSERT_EQUAL_INT(1, xfer_count);
+
+    written = tu_txbuf_write_n(&txbuf, data, 11);
+    // We can queue all 11 bytes but they are split.
+    TEST_ASSERT_EQUAL_INT(11, written);
+    // Four immediately and seven more after the callback.
+    TEST_ASSERT_EQUAL_INT(2, xfer_count);
+    TEST_ASSERT_EQUAL_INT(4, freshly_transmitted);
+    xfer_callback();
+    TEST_ASSERT_EQUAL_INT(7, freshly_transmitted);
+    TEST_ASSERT_EQUAL_INT(3, xfer_count);
+}
+
+// Test that we only accept the data even when we have to wrap around.
+void test_wrap_around_too_much(void) {
+    uint16_t written = tu_txbuf_write_n(&txbuf, data, 11);
+    TEST_ASSERT_EQUAL_INT(11, written);
+    TEST_ASSERT_EQUAL_INT(1, xfer_count);
+    xfer_callback();
+    TEST_ASSERT_EQUAL_INT(1, xfer_count);
+
+    written = tu_txbuf_write_n(&txbuf, data, 17);
+    // We can queue 16 of 17 bytes but they are split.
+    TEST_ASSERT_EQUAL_INT(16, written);
+    // Four immediately and 12 more after the callback.
+    TEST_ASSERT_EQUAL_INT(2, xfer_count);
+    TEST_ASSERT_EQUAL_INT(4, freshly_transmitted);
+    xfer_callback();
+    TEST_ASSERT_EQUAL_INT(12, freshly_transmitted);
+    TEST_ASSERT_EQUAL_INT(3, xfer_count);
+}
+
+int main(void)
+{
+UNITY_BEGIN();
+RUN_TEST(test_normal);
+RUN_TEST(test_nearly_full);
+RUN_TEST(test_wrap_around);
+RUN_TEST(test_wrap_around_too_much);
+return UNITY_END();
+}
diff --git a/tests/vendor/unity b/tests/vendor/unity
new file mode 160000
+Subproject a2849843654524194b72567b198c25d1c1dfead