tinyusb/examples/device/audio_4_channel_mic/src/main.c

/*
 * The MIT License (MIT)
 *
 * Copyright (c) 2020 Reinhard Panhuber
 *
 * 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.
 *
 */

/* plot_audio_samples.py requires following modules:
 * $ sudo apt install libportaudio
 * $ pip3 install sounddevice matplotlib
 *
 * Then run
 * $ python3 plot_audio_samples.py
 */

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <math.h>

#include "bsp/board_api.h"
#include "tusb.h"
#include "tusb_config.h"

//--------------------------------------------------------------------+
// MACRO CONSTANT TYPEDEF PROTYPES
//--------------------------------------------------------------------+
#define AUDIO_SAMPLE_RATE   CFG_TUD_AUDIO_FUNC_1_SAMPLE_RATE

/* 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;

// Audio controls
// Current states
bool mute[CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_TX + 1]; 				          // +1 for master channel 0
uint16_t volume[CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_TX + 1]; 					// +1 for master channel 0
uint32_t sampFreq;
uint8_t clkValid;

// Range states
audio_control_range_2_n_t(1) volumeRng[CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_TX+1]; 			// Volume range state
audio_control_range_4_n_t(1) sampleFreqRng; 						// Sample frequency range state

#if CFG_TUD_AUDIO_ENABLE_ENCODING
// Audio test data, each buffer contains 2 channels, buffer[0] for CH0-1, buffer[1] for CH1-2
uint16_t i2s_dummy_buffer[CFG_TUD_AUDIO_FUNC_1_N_TX_SUPP_SW_FIFO][CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_TX*CFG_TUD_AUDIO_FUNC_1_SAMPLE_RATE/1000/CFG_TUD_AUDIO_FUNC_1_N_TX_SUPP_SW_FIFO];
#else
// Audio test data, 4 channels muxed together, buffer[0] for CH0, buffer[1] for CH1, buffer[2] for CH2, buffer[3] for CH3
uint16_t i2s_dummy_buffer[CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_TX*CFG_TUD_AUDIO_FUNC_1_SAMPLE_RATE/1000];
#endif

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

/*------------- MAIN -------------*/
int main(void)
{
  board_init();

  // init device stack on configured roothub port
  tud_init(BOARD_TUD_RHPORT);

  if (board_init_after_tusb) {
    board_init_after_tusb();
  }

  // Init values
  sampFreq = AUDIO_SAMPLE_RATE;
  clkValid = 1;

  sampleFreqRng.wNumSubRanges = 1;
  sampleFreqRng.subrange[0].bMin = AUDIO_SAMPLE_RATE;
  sampleFreqRng.subrange[0].bMax = AUDIO_SAMPLE_RATE;
  sampleFreqRng.subrange[0].bRes = 0;

  // Generate dummy data
#if CFG_TUD_AUDIO_ENABLE_ENCODING
  uint16_t * p_buff = i2s_dummy_buffer[0];
  uint16_t dataVal = 1;
  for (uint16_t cnt = 0; cnt < AUDIO_SAMPLE_RATE/1000; cnt++)
  {
    // CH0 saw wave
    *p_buff++ = dataVal;
    // CH1 inverted saw wave
    *p_buff++ = 60 + AUDIO_SAMPLE_RATE/1000 - dataVal;
    dataVal++;
  }
  p_buff = i2s_dummy_buffer[1];
  for (uint16_t cnt = 0; cnt < AUDIO_SAMPLE_RATE/1000; cnt++)
  {
    // CH3 square wave
    *p_buff++ = cnt < (AUDIO_SAMPLE_RATE/1000/2) ? 120:170;
    // CH4 sinus wave
    float t = 2*3.1415f * cnt / (AUDIO_SAMPLE_RATE/1000);
    *p_buff++ = (uint16_t)(sinf(t) * 25) + 200;
  }
#else
  uint16_t * p_buff = i2s_dummy_buffer;
  uint16_t dataVal = 1;
  for (uint16_t cnt = 0; cnt < AUDIO_SAMPLE_RATE/1000; cnt++)
  {
    // CH0 saw wave
    *p_buff++ = dataVal;
    // CH1 inverted saw wave
    *p_buff++ = 60 + AUDIO_SAMPLE_RATE/1000 - dataVal;
    dataVal++;
    // CH3 square wave
    *p_buff++ = cnt < (AUDIO_SAMPLE_RATE/1000/2) ? 120:170;
    // CH4 sinus wave
    float t = 2*3.1415f * cnt / (AUDIO_SAMPLE_RATE/1000);
    *p_buff++ = (uint16_t)(sinf(t) * 25) + 200;
  }
#endif

  while (1)
  {
    tud_task(); // tinyusb device task
    led_blinking_task();
    audio_task();
  }
}

//--------------------------------------------------------------------+
// 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 = tud_mounted() ? BLINK_MOUNTED : BLINK_NOT_MOUNTED;
}

//--------------------------------------------------------------------+
// AUDIO Task
//--------------------------------------------------------------------+

void audio_task(void)
{
  // Yet to be filled - e.g. read audio from I2S buffer.
  // Here we simulate a I2S receive callback every 1ms.
  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;
#if CFG_TUD_AUDIO_ENABLE_ENCODING
  // Write I2S buffer into FIFO
  for (uint8_t cnt=0; cnt < 2; cnt++)
  {
    tud_audio_write_support_ff(cnt, i2s_dummy_buffer[cnt], AUDIO_SAMPLE_RATE/1000 * CFG_TUD_AUDIO_FUNC_1_N_BYTES_PER_SAMPLE_TX * CFG_TUD_AUDIO_FUNC_1_CHANNEL_PER_FIFO_TX);
  }
#else
  tud_audio_write(i2s_dummy_buffer, AUDIO_SAMPLE_RATE/1000 * CFG_TUD_AUDIO_FUNC_1_N_BYTES_PER_SAMPLE_TX * CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_TX);
#endif
}

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

// Invoked when audio class specific set request received for an EP
bool tud_audio_set_req_ep_cb(uint8_t rhport, tusb_control_request_t const * p_request, uint8_t *pBuff)
{
  (void) rhport;
  (void) pBuff;

  // We do not support any set range requests here, only current value requests
  TU_VERIFY(p_request->bRequest == AUDIO_CS_REQ_CUR);

  // Page 91 in UAC2 specification
  uint8_t channelNum = TU_U16_LOW(p_request->wValue);
  uint8_t ctrlSel = TU_U16_HIGH(p_request->wValue);
  uint8_t ep = TU_U16_LOW(p_request->wIndex);

  (void) channelNum; (void) ctrlSel; (void) ep;

  return false; 	// Yet not implemented
}

// Invoked when audio class specific set request received for an interface
bool tud_audio_set_req_itf_cb(uint8_t rhport, tusb_control_request_t const * p_request, uint8_t *pBuff)
{
  (void) rhport;
  (void) pBuff;

  // We do not support any set range requests here, only current value requests
  TU_VERIFY(p_request->bRequest == AUDIO_CS_REQ_CUR);

  // Page 91 in UAC2 specification
  uint8_t channelNum = TU_U16_LOW(p_request->wValue);
  uint8_t ctrlSel = TU_U16_HIGH(p_request->wValue);
  uint8_t itf = TU_U16_LOW(p_request->wIndex);

  (void) channelNum; (void) ctrlSel; (void) itf;

  return false; 	// Yet not implemented
}

// 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 *pBuff)
{
  (void) rhport;

  // Page 91 in UAC2 specification
  uint8_t channelNum = TU_U16_LOW(p_request->wValue);
  uint8_t ctrlSel = TU_U16_HIGH(p_request->wValue);
  uint8_t itf = TU_U16_LOW(p_request->wIndex);
  uint8_t entityID = TU_U16_HIGH(p_request->wIndex);

  (void) itf;

  // We do not support any set range requests here, only current value requests
  TU_VERIFY(p_request->bRequest == AUDIO_CS_REQ_CUR);

  // If request is for our feature unit
  if ( entityID == 2 )
  {
    switch ( ctrlSel )
    {
      case AUDIO_FU_CTRL_MUTE:
        // Request uses format layout 1
        TU_VERIFY(p_request->wLength == sizeof(audio_control_cur_1_t));

        mute[channelNum] = ((audio_control_cur_1_t*) pBuff)->bCur;

        TU_LOG2("    Set Mute: %d of channel: %u\r\n", mute[channelNum], channelNum);
      return true;

      case AUDIO_FU_CTRL_VOLUME:
        // Request uses format layout 2
        TU_VERIFY(p_request->wLength == sizeof(audio_control_cur_2_t));

        volume[channelNum] = (uint16_t) ((audio_control_cur_2_t*) pBuff)->bCur;

        TU_LOG2("    Set Volume: %d dB of channel: %u\r\n", volume[channelNum], channelNum);
      return true;

        // Unknown/Unsupported control
      default:
        TU_BREAKPOINT();
      return false;
    }
  }
  return false;    // Yet not implemented
}

// Invoked when audio class specific get request received for an EP
bool tud_audio_get_req_ep_cb(uint8_t rhport, tusb_control_request_t const * p_request)
{
  (void) rhport;

  // Page 91 in UAC2 specification
  uint8_t channelNum = TU_U16_LOW(p_request->wValue);
  uint8_t ctrlSel = TU_U16_HIGH(p_request->wValue);
  uint8_t ep = TU_U16_LOW(p_request->wIndex);

  (void) channelNum; (void) ctrlSel; (void) ep;

  //	return tud_control_xfer(rhport, p_request, &tmp, 1);

  return false; 	// Yet not implemented
}

// Invoked when audio class specific get request received for an interface
bool tud_audio_get_req_itf_cb(uint8_t rhport, tusb_control_request_t const * p_request)
{
  (void) rhport;

  // Page 91 in UAC2 specification
  uint8_t channelNum = TU_U16_LOW(p_request->wValue);
  uint8_t ctrlSel = TU_U16_HIGH(p_request->wValue);
  uint8_t itf = TU_U16_LOW(p_request->wIndex);

  (void) channelNum; (void) ctrlSel; (void) itf;

  return false; 	// Yet not implemented
}

// 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)
{
  (void) rhport;

  // Page 91 in UAC2 specification
  uint8_t channelNum = TU_U16_LOW(p_request->wValue);
  uint8_t ctrlSel = TU_U16_HIGH(p_request->wValue);
  // uint8_t itf = TU_U16_LOW(p_request->wIndex); 			// Since we have only one audio function implemented, we do not need the itf value
  uint8_t entityID = TU_U16_HIGH(p_request->wIndex);

  // Input terminal (Microphone input)
  if (entityID == 1)
  {
    switch ( ctrlSel )
    {
      case AUDIO_TE_CTRL_CONNECTOR:
      {
        // The terminal connector control only has a get request with only the CUR attribute.
        audio_desc_channel_cluster_t ret;

        // Those are dummy values for now
        ret.bNrChannels = 1;
        ret.bmChannelConfig = (audio_channel_config_t) 0;
        ret.iChannelNames = 0;

        TU_LOG2("    Get terminal connector\r\n");

        return tud_audio_buffer_and_schedule_control_xfer(rhport, p_request, (void*) &ret, sizeof(ret));
      }
      break;

        // Unknown/Unsupported control selector
      default:
        TU_BREAKPOINT();
        return false;
    }
  }

  // Feature unit
  if (entityID == 2)
  {
    switch ( ctrlSel )
    {
      case AUDIO_FU_CTRL_MUTE:
        // Audio control mute cur parameter block consists of only one byte - we thus can send it right away
        // There does not exist a range parameter block for mute
        TU_LOG2("    Get Mute of channel: %u\r\n", channelNum);
        return tud_control_xfer(rhport, p_request, &mute[channelNum], 1);

      case AUDIO_FU_CTRL_VOLUME:
        switch ( p_request->bRequest )
        {
          case AUDIO_CS_REQ_CUR:
            TU_LOG2("    Get Volume of channel: %u\r\n", channelNum);
            return tud_control_xfer(rhport, p_request, &volume[channelNum], sizeof(volume[channelNum]));

          case AUDIO_CS_REQ_RANGE:
            TU_LOG2("    Get Volume range of channel: %u\r\n", channelNum);

            // Copy values - only for testing - better is version below
            audio_control_range_2_n_t(1)
            ret;

            ret.wNumSubRanges = 1;
            ret.subrange[0].bMin = -90;           // -90 dB
            ret.subrange[0].bMax = 90;		// +90 dB
            ret.subrange[0].bRes = 1; 		// 1 dB steps

            return tud_audio_buffer_and_schedule_control_xfer(rhport, p_request, (void*) &ret, sizeof(ret));

            // Unknown/Unsupported control
          default:
            TU_BREAKPOINT();
            return false;
        }
      break;

        // Unknown/Unsupported control
      default:
        TU_BREAKPOINT();
        return false;
    }
  }

  // Clock Source unit
  if ( entityID == 4 )
  {
    switch ( ctrlSel )
    {
      case AUDIO_CS_CTRL_SAM_FREQ:
        // channelNum is always zero in this case
        switch ( p_request->bRequest )
        {
          case AUDIO_CS_REQ_CUR:
            TU_LOG2("    Get Sample Freq.\r\n");
            // Buffered control transfer is needed for IN flow control to work
            return tud_audio_buffer_and_schedule_control_xfer(rhport, p_request, &sampFreq, sizeof(sampFreq));

          case AUDIO_CS_REQ_RANGE:
            TU_LOG2("    Get Sample Freq. range\r\n");
            return tud_control_xfer(rhport, p_request, &sampleFreqRng, sizeof(sampleFreqRng));

           // Unknown/Unsupported control
          default:
            TU_BREAKPOINT();
            return false;
        }
      break;

      case AUDIO_CS_CTRL_CLK_VALID:
        // Only cur attribute exists for this request
        TU_LOG2("    Get Sample Freq. valid\r\n");
        return tud_control_xfer(rhport, p_request, &clkValid, sizeof(clkValid));

      // Unknown/Unsupported control
      default:
        TU_BREAKPOINT();
        return false;
    }
  }

  TU_LOG2("  Unsupported entity: %d\r\n", entityID);
  return false; 	// Yet not implemented
}

bool tud_audio_tx_done_pre_load_cb(uint8_t rhport, uint8_t itf, uint8_t ep_in, uint8_t cur_alt_setting)
{
  (void) rhport;
  (void) itf;
  (void) ep_in;
  (void) cur_alt_setting;


  // In read world application data flow is driven by I2S clock,
  // both tud_audio_tx_done_pre_load_cb() & tud_audio_tx_done_post_load_cb() are hardly used.
  // For example in your I2S receive callback:
  // void I2S_Rx_Callback(int channel, const void* data, uint16_t samples)
  // {
  //    tud_audio_write_support_ff(channel, data, samples * N_BYTES_PER_SAMPLE * N_CHANNEL_PER_FIFO);
  // }

  return true;
}

bool tud_audio_tx_done_post_load_cb(uint8_t rhport, uint16_t n_bytes_copied, uint8_t itf, uint8_t ep_in, uint8_t cur_alt_setting)
{
  (void) rhport;
  (void) n_bytes_copied;
  (void) itf;
  (void) ep_in;
  (void) cur_alt_setting;

  return true;
}

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

  return true;
}

//--------------------------------------------------------------------+
// 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
}