TinyUSB uac2_speaker_fb minimal example on STM32F723E-DISCO

main.c

/*
 * The MIT License (MIT)
 *
 * Copyright (c) 2020 Jerzy Kasenberg
 * Copyright (c) 2023 HiFiPhile
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * 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 <stdio.h>
#include <string.h>

#include "bsp/board_api.h"
#include "tusb.h"
#include "usb_descriptors.h"
#include "common_types.h"

#include "stm32f723e_discovery.h"
#include "stm32f723e_discovery_audio.h"

//--------------------------------------------------------------------+
// MACRO CONSTANT TYPEDEF PROTOTYPES
//--------------------------------------------------------------------+

// List of supported sample rates
#if defined(__RX__)
  const uint32_t sample_rates[] = {44100, 48000};
#else
  const uint32_t sample_rates[] = {44100, 48000, 88200, 96000};
#endif

uint32_t current_sample_rate  = 44100;

#define N_SAMPLE_RATES  TU_ARRAY_SIZE(sample_rates)
#define FRAME_SIZE (32 * CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_RX * CFG_TUD_AUDIO_FUNC_1_N_BYTES_PER_SAMPLE_RX)
/* Blink pattern
 * - 25 ms   : streaming data
 * - 250 ms  : device not mounted
 * - 1000 ms : device mounted
 * - 2500 ms : device is suspended
 */
enum
{
  BLINK_STREAMING = 25,
  BLINK_NOT_MOUNTED = 250,
  BLINK_MOUNTED = 1000,
  BLINK_SUSPENDED = 2500,
};

enum
{
  VOLUME_CTRL_0_DB = 0,
  VOLUME_CTRL_10_DB = 2560,
  VOLUME_CTRL_20_DB = 5120,
  VOLUME_CTRL_30_DB = 7680,
  VOLUME_CTRL_40_DB = 10240,
  VOLUME_CTRL_50_DB = 12800,
  VOLUME_CTRL_60_DB = 15360,
  VOLUME_CTRL_70_DB = 17920,
  VOLUME_CTRL_80_DB = 20480,
  VOLUME_CTRL_90_DB = 23040,
  VOLUME_CTRL_100_DB = 25600,
  VOLUME_CTRL_SILENCE = 0x8000,
};

static uint32_t blink_interval_ms = BLINK_NOT_MOUNTED;

// Audio controls
// Current states
int8_t mute[CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_RX + 1];       // +1 for master channel 0
int16_t volume[CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_RX + 1];    // +1 for master channel 0

// Buffer for speaker data
uint16_t i2s_buffer[FRAME_SIZE/2];

void led_blinking_task(void);
void audio_task(void);

#if CFG_AUDIO_DEBUG
void audio_debug_task(void);
uint8_t current_alt_settings;
#endif

/*------------- MAIN -------------*/
int main(void)
{
  board_init();
  
  // 70 volume is very loud !
  BSP_AUDIO_OUT_Init(OUTPUT_DEVICE_HEADPHONE, 70, I2S_AUDIOFREQ_48K);
  BSP_AUDIO_OUT_SetAudioFrameSlot(CODEC_AUDIOFRAME_SLOT_02);
  // init device stack on configured roothub port
  tud_init(BOARD_TUD_RHPORT);

  if (board_init_after_tusb) {
    board_init_after_tusb();
  }

  TU_LOG1("Speaker running\r\n");

  while (1)
  {
    tud_task(); // TinyUSB device task
    led_blinking_task();
#if CFG_AUDIO_DEBUG
    audio_debug_task();
#endif
  }
}

//--------------------------------------------------------------------+
// 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;
  BSP_AUDIO_OUT_Stop(CODEC_PDWN_SW);
}

// 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;
  BSP_AUDIO_OUT_Stop(CODEC_PDWN_SW);
  blink_interval_ms = BLINK_SUSPENDED;
}

// Invoked when usb bus is resumed
void tud_resume_cb(void)
{
  blink_interval_ms = tud_mounted() ? BLINK_MOUNTED : BLINK_NOT_MOUNTED;
}

//--------------------------------------------------------------------+
// Application Callback API Implementations
//--------------------------------------------------------------------+

/**
  * @brief  Calculates the remaining file size and new position of the pointer.
  * @param  None
  * @retval None
  */
void BSP_AUDIO_OUT_TransferComplete_CallBack(void)
{
  tud_audio_read((uint8_t*)i2s_buffer + FRAME_SIZE / 2, FRAME_SIZE/2);
}

/**
  * @brief  Manages the DMA Half Transfer complete interrupt.
  * @param  None
  * @retval None
  */
void BSP_AUDIO_OUT_HalfTransfer_CallBack(void)
{ 
  tud_audio_read(i2s_buffer, FRAME_SIZE/2);
}

// Helper for clock get requests
static bool tud_audio_clock_get_request(uint8_t rhport, audio_control_request_t const *request)
{
  TU_ASSERT(request->bEntityID == UAC2_ENTITY_CLOCK);

  if (request->bControlSelector == AUDIO_CS_CTRL_SAM_FREQ)
  {
    if (request->bRequest == AUDIO_CS_REQ_CUR)
    {
      TU_LOG1("Clock get current freq %lu\r\n", current_sample_rate);

      audio_control_cur_4_t curf = { (int32_t) tu_htole32(current_sample_rate) };
      return tud_audio_buffer_and_schedule_control_xfer(rhport, (tusb_control_request_t const *)request, &curf, sizeof(curf));
    }
    else if (request->bRequest == AUDIO_CS_REQ_RANGE)
    {
      audio_control_range_4_n_t(N_SAMPLE_RATES) rangef =
      {
        .wNumSubRanges = tu_htole16(N_SAMPLE_RATES)
      };
      TU_LOG1("Clock get %d freq ranges\r\n", N_SAMPLE_RATES);
      for(uint8_t i = 0; i < N_SAMPLE_RATES; i++)
      {
        rangef.subrange[i].bMin = (int32_t) sample_rates[i];
        rangef.subrange[i].bMax = (int32_t) sample_rates[i];
        rangef.subrange[i].bRes = 0;
        TU_LOG1("Range %d (%d, %d, %d)\r\n", i, (int)rangef.subrange[i].bMin, (int)rangef.subrange[i].bMax, (int)rangef.subrange[i].bRes);
      }

      return tud_audio_buffer_and_schedule_control_xfer(rhport, (tusb_control_request_t const *)request, &rangef, sizeof(rangef));
    }
  }
  else if (request->bControlSelector == AUDIO_CS_CTRL_CLK_VALID &&
           request->bRequest == AUDIO_CS_REQ_CUR)
  {
    audio_control_cur_1_t cur_valid = { .bCur = 1 };
    TU_LOG1("Clock get is valid %u\r\n", cur_valid.bCur);
    return tud_audio_buffer_and_schedule_control_xfer(rhport, (tusb_control_request_t const *)request, &cur_valid, sizeof(cur_valid));
  }
  TU_LOG1("Clock get request not supported, entity = %u, selector = %u, request = %u\r\n",
          request->bEntityID, request->bControlSelector, request->bRequest);
  return false;
}

// Helper for clock set requests
static bool tud_audio_clock_set_request(uint8_t rhport, audio_control_request_t const *request, uint8_t const *buf)
{
  (void)rhport;

  TU_ASSERT(request->bEntityID == UAC2_ENTITY_CLOCK);
  TU_VERIFY(request->bRequest == AUDIO_CS_REQ_CUR);

  if (request->bControlSelector == AUDIO_CS_CTRL_SAM_FREQ)
  {
    TU_VERIFY(request->wLength == sizeof(audio_control_cur_4_t));

    current_sample_rate = (uint32_t) ((audio_control_cur_4_t const *)buf)->bCur;

    TU_LOG1("Clock set current freq: %ld\r\n", current_sample_rate);

    return true;
  }
  else
  {
    TU_LOG1("Clock set request not supported, entity = %u, selector = %u, request = %u\r\n",
            request->bEntityID, request->bControlSelector, request->bRequest);
    return false;
  }
}

// Helper for feature unit get requests
static bool tud_audio_feature_unit_get_request(uint8_t rhport, audio_control_request_t const *request)
{
  TU_ASSERT(request->bEntityID == UAC2_ENTITY_FEATURE_UNIT);

  if (request->bControlSelector == AUDIO_FU_CTRL_MUTE && request->bRequest == AUDIO_CS_REQ_CUR)
  {
    audio_control_cur_1_t mute1 = { .bCur = mute[request->bChannelNumber] };
    TU_LOG1("Get channel %u mute %d\r\n", request->bChannelNumber, mute1.bCur);
    return tud_audio_buffer_and_schedule_control_xfer(rhport, (tusb_control_request_t const *)request, &mute1, sizeof(mute1));
  }
  else if (request->bControlSelector == AUDIO_FU_CTRL_VOLUME)
  {
    if (request->bRequest == AUDIO_CS_REQ_RANGE)
    {
      audio_control_range_2_n_t(1) range_vol = {
        .wNumSubRanges = tu_htole16(1),
        .subrange[0] = { .bMin = tu_htole16(-VOLUME_CTRL_50_DB), tu_htole16(VOLUME_CTRL_0_DB), tu_htole16(256) }
      };
      TU_LOG1("Get channel %u volume range (%d, %d, %u) dB\r\n", request->bChannelNumber,
              range_vol.subrange[0].bMin / 256, range_vol.subrange[0].bMax / 256, range_vol.subrange[0].bRes / 256);
      return tud_audio_buffer_and_schedule_control_xfer(rhport, (tusb_control_request_t const *)request, &range_vol, sizeof(range_vol));
    }
    else if (request->bRequest == AUDIO_CS_REQ_CUR)
    {
      audio_control_cur_2_t cur_vol = { .bCur = tu_htole16(volume[request->bChannelNumber]) };
      TU_LOG1("Get channel %u volume %d dB\r\n", request->bChannelNumber, cur_vol.bCur / 256);
      return tud_audio_buffer_and_schedule_control_xfer(rhport, (tusb_control_request_t const *)request, &cur_vol, sizeof(cur_vol));
    }
  }
  TU_LOG1("Feature unit get request not supported, entity = %u, selector = %u, request = %u\r\n",
          request->bEntityID, request->bControlSelector, request->bRequest);

  return false;
}

// Helper for feature unit set requests
static bool tud_audio_feature_unit_set_request(uint8_t rhport, audio_control_request_t const *request, uint8_t const *buf)
{
  (void)rhport;

  TU_ASSERT(request->bEntityID == UAC2_ENTITY_FEATURE_UNIT);
  TU_VERIFY(request->bRequest == AUDIO_CS_REQ_CUR);

  if (request->bControlSelector == AUDIO_FU_CTRL_MUTE)
  {
    TU_VERIFY(request->wLength == sizeof(audio_control_cur_1_t));

    mute[request->bChannelNumber] = ((audio_control_cur_1_t const *)buf)->bCur;

    TU_LOG1("Set channel %d Mute: %d\r\n", request->bChannelNumber, mute[request->bChannelNumber]);

    return true;
  }
  else if (request->bControlSelector == AUDIO_FU_CTRL_VOLUME)
  {
    TU_VERIFY(request->wLength == sizeof(audio_control_cur_2_t));

    volume[request->bChannelNumber] = ((audio_control_cur_2_t const *)buf)->bCur;

    TU_LOG1("Set channel %d volume: %d dB\r\n", request->bChannelNumber, volume[request->bChannelNumber] / 256);

    return true;
  }
  else
  {
    TU_LOG1("Feature unit set request not supported, entity = %u, selector = %u, request = %u\r\n",
            request->bEntityID, request->bControlSelector, request->bRequest);
    return false;
  }
}

// Invoked when audio class specific get request received for an entity
bool tud_audio_get_req_entity_cb(uint8_t rhport, tusb_control_request_t const *p_request)
{
  audio_control_request_t const *request = (audio_control_request_t const *)p_request;

  if (request->bEntityID == UAC2_ENTITY_CLOCK)
    return tud_audio_clock_get_request(rhport, request);
  if (request->bEntityID == UAC2_ENTITY_FEATURE_UNIT)
    return tud_audio_feature_unit_get_request(rhport, request);
  else
  {
    TU_LOG1("Get request not handled, entity = %d, selector = %d, request = %d\r\n",
            request->bEntityID, request->bControlSelector, request->bRequest);
  }
  return false;
}

// Invoked when audio class specific set request received for an entity
bool tud_audio_set_req_entity_cb(uint8_t rhport, tusb_control_request_t const *p_request, uint8_t *buf)
{
  audio_control_request_t const *request = (audio_control_request_t const *)p_request;

  if (request->bEntityID == UAC2_ENTITY_FEATURE_UNIT)
    return tud_audio_feature_unit_set_request(rhport, request, buf);
  if (request->bEntityID == UAC2_ENTITY_CLOCK)
    return tud_audio_clock_set_request(rhport, request, buf);
  TU_LOG1("Set request not handled, entity = %d, selector = %d, request = %d\r\n",
          request->bEntityID, request->bControlSelector, request->bRequest);

  return false;
}

bool tud_audio_set_itf_close_EP_cb(uint8_t rhport, tusb_control_request_t const * p_request)
{
  (void)rhport;

  uint8_t const itf = tu_u16_low(tu_le16toh(p_request->wIndex));
  uint8_t const alt = tu_u16_low(tu_le16toh(p_request->wValue));

  if (ITF_NUM_AUDIO_STREAMING == itf && alt == 0)
  {
      BSP_AUDIO_OUT_Stop(CODEC_PDWN_SW);
      memset(i2s_buffer, 0, sizeof(i2s_buffer));
      blink_interval_ms = BLINK_MOUNTED;
  }

  return true;
}

bool tud_audio_set_itf_cb(uint8_t rhport, tusb_control_request_t const * p_request)
{
  (void)rhport;
  uint8_t const itf = tu_u16_low(tu_le16toh(p_request->wIndex));
  uint8_t const alt = tu_u16_low(tu_le16toh(p_request->wValue));

  TU_LOG2("Set interface %d alt %d\r\n", itf, alt);
  if (ITF_NUM_AUDIO_STREAMING == itf && alt != 0)
      blink_interval_ms = BLINK_STREAMING;
      BSP_AUDIO_OUT_SetFrequency(current_sample_rate);
      BSP_AUDIO_OUT_Play(i2s_buffer, FRAME_SIZE);
      BSP_AUDIO_OUT_Resume();
#if CFG_AUDIO_DEBUG
  current_alt_settings = alt;
#endif

  return true;
}

void tud_audio_feedback_params_cb(uint8_t func_id, uint8_t alt_itf, audio_feedback_params_t* feedback_param)
{
  (void)func_id;
  (void)alt_itf;
  // Set feedback method to fifo counting
  feedback_param->method = AUDIO_FEEDBACK_METHOD_FIFO_COUNT;
  feedback_param->sample_freq = current_sample_rate;
}

//--------------------------------------------------------------------+
// 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;
  start_ms += blink_interval_ms;

  board_led_write(led_state);
  led_state = 1 - led_state;
}

#if CFG_AUDIO_DEBUG
//--------------------------------------------------------------------+
// HID interface for audio debug
//--------------------------------------------------------------------+
static uint32_t fifo_count_avg;

// Every 1ms, we will sent 1 debug information report
void audio_debug_task(void)
{
  static uint32_t start_ms = 0;
  uint32_t curr_ms = board_millis();
  if ( start_ms == curr_ms ) return; // not enough time
  start_ms = curr_ms;

  uint16_t fifo_count = tud_audio_available();

  // Same averaging method used in UAC2 class
  fifo_count_avg = (uint32_t)(((uint64_t)fifo_count_avg * 63  + ((uint32_t)fifo_count << 16)) >> 6);

  audio_debug_info_t debug_info;
  debug_info.sample_rate    = current_sample_rate;
  debug_info.alt_settings   = current_alt_settings;
  debug_info.fifo_size      = CFG_TUD_AUDIO_FUNC_1_EP_OUT_SW_BUF_SZ;
  debug_info.fifo_count     = fifo_count;
  debug_info.fifo_count_avg = fifo_count_avg >> 16;
  for (int i = 0; i < CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_RX + 1; i++)
  {
    debug_info.mute[i] = mute[i];
    debug_info.volume[i] = volume[i];
  }

  if(tud_hid_ready())
    tud_hid_report(0, &debug_info, sizeof(debug_info));
}

// Invoked when received GET_REPORT control request
// Unused here
uint16_t tud_hid_get_report_cb(uint8_t itf, uint8_t report_id, hid_report_type_t report_type, uint8_t* buffer, uint16_t reqlen)
{
  // TODO not Implemented
  (void) itf;
  (void) report_id;
  (void) report_type;
  (void) buffer;
  (void) reqlen;

  return 0;
}

// Invoked when received SET_REPORT control request or
// Unused here
void tud_hid_set_report_cb(uint8_t itf, uint8_t report_id, hid_report_type_t report_type, uint8_t const* buffer, uint16_t bufsize)
{
  // This example doesn't use multiple report and report ID
  (void) itf;
  (void) report_id;
  (void) report_type;
  (void) buffer;
  (void) bufsize;
}

#endif

extern SAI_HandleTypeDef haudio_out_sai;
/**
  * @brief This function handles DMA2 Stream 4 interrupt request.
  * @param None
  * @retval None
  */
void AUDIO_OUT_SAIx_DMAx_IRQHandler(void)
{
  HAL_DMA_IRQHandler(haudio_out_sai.hdmatx);
}

External dependencies:

• STM32Cube_FW_F7_V1.17.1\Drivers\BSP\STM32F723E-Discovery
  • stm32f723e_discovery.c/.h
  • stm32f723e_discovery_audio.c/h
• STM32Cube_FW_F7_V1.17.1\Drivers\BSP\Components\wm8994
  -wm8994.c/h