audio.c

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/******************************************************************************
 *  Copyright (c) 2016, Xilinx, Inc.
 *  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 holder 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 AND CONTRIBUTORS "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 OR
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 *  PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
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 *  OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 *  ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *****************************************************************************/
 
/******************************************************************************
 * @file audio_adau1761.c
 *
 * Functions to control audio controller.
 *
 * <pre>
 * MODIFICATION HISTORY:
 *
 * Ver   Who          Date     Changes
 * ----- ------------ -------- -----------------------------------------------
 * 1.00  Yun Rock Qu  12/04/17 Support for audio codec ADAU1761
 * 1.01  Yun Rock Qu  01/02/18 Enable microphone for CTIA and OMTP standards
 *
 * </pre>
 *
 *****************************************************************************/
#include "audio.h"
#include <libpynq.h>
#include <stdint.h>
 
#include "i2cps.h"
#include "uio.h"
#include <fcntl.h>
#include <linux/i2c-dev.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <time.h>
#include <unistd.h>
 
#define SAMPLE_RATE 44100
 
#undef LOG_DOMAIN
#define LOG_DOMAIN "audio"
 
void audio_init(void) {
  config_audio_pll();
  config_audio_codec();
}
 
void audio_select_input(int input) {
  if (input == MIC) {
    select_mic();
  } else if (input == LINE_IN) {
    select_line_in();
  } else {
    pynq_error("audio_select_input: invalid input %d, must be LINE_IN or MIC\n",
               input);
  }
}
 
// Original ADAU1761 code
 
void write_audio_reg(unsigned char u8RegAddr, unsigned char u8Data,
                     int iic_fd) {
  unsigned char u8TxData[3];
  u8TxData[0] = 0x40;
  u8TxData[1] = u8RegAddr;
  u8TxData[2] = u8Data;
  if (writeI2C_asFile(iic_fd, u8TxData, 3) < 0) {
    pynq_error("write_audio_reg: unable to write audio register, ensure sudo "
               "chmod 666 /dev/i2c-1 has been executed. \n");
  }
}
 
void config_audio_pll(void) {
  int iic_index = 1;
  unsigned char u8TxData[8], u8RxData[6];
  int iic_fd;
  iic_fd = setI2C(iic_index, IIC_SLAVE_ADDR);
  if (iic_fd < 0) {
    pynq_error("config_audio_pll: unable to set I2C %d\n", iic_index);
  }
 
  // Disable Core Clock
  write_audio_reg(R0_CLOCK_CONTROL, 0x0E, iic_fd);
  /*  MCLK = 10 MHz
   *  R = 0100 = 4, N = 0x064C = 1612, M = 0x0C35 = 3125
   *  PLL required output = 1024x44.1 KHz = 45.1584 MHz
   *  PLLout/MCLK         = 45.1584 MHz/10 MHz = 4.51584 MHz
   *                      = R + (N/M)
   *                      = 4 + (1612/3125)
   *  Fs = PLL/1024 = 44.1 KHz
   */
 
  // Register write address [15:8]
  u8TxData[0] = 0x40;
  // Register write address [7:0]
  u8TxData[1] = 0x02;
  // byte 6 - M[15:8]
  u8TxData[2] = 0x0C;
  // byte 5 - M[7:0]
  u8TxData[3] = 0x35;
  // byte 4 - N[15:8]
  u8TxData[4] = 0x06;
  // byte 3 - N[7:0]
  u8TxData[5] = 0x4C;
  // byte 2 - bits 6:3 = R[3:0], 2:1 = X[1:0], 0 = PLL operation mode
  u8TxData[6] = 0x21;
  // byte 1 - 1 = PLL Lock, 0 = Core clock enable
  u8TxData[7] = 0x03;
  // Write bytes to PLL control register R1 at 0x4002
  if (writeI2C_asFile(iic_fd, u8TxData, 8) < 0) {
    pynq_error("config_audio_pll: unable to write audio register, ensure sudo "
               "chmod 666 /dev/i2c-1 has been executed. \n");
  }
 
  // Poll PLL Lock bit
  u8TxData[0] = 0x40;
  u8TxData[1] = 0x02;
  do {
    if (writeI2C_asFile(iic_fd, u8TxData, 2) < 0) {
      pynq_error("writeI2C_asFile: unable to write audio register, ensure sudo "
                 "chmod 666 /dev/i2c-1 has been executed. \n");
    }
    if (readI2C_asFile(iic_fd, u8RxData, 6) < 0) {
      pynq_error("readI2C_asFile: unable to write audio register, ensure sudo "
                 "chmod 666 /dev/i2c-1 has been executed. \n");
    }
  } while ((u8RxData[5] & 0x02) == 0);
 
  /* Clock control register:  bit 3        CLKSRC = PLL Clock input
   *                          bit 2:1      INFREQ = 1024 x fs
   *                          bit 0        COREN = Core Clock enabled
   */
  write_audio_reg(R0_CLOCK_CONTROL, 0x0F, iic_fd);
 
  if (unsetI2C(iic_fd) < 0) {
    pynq_error("config_audio_pll: unable to set I2C %d\n", iic_fd);
  }
}
 
/******************************************************************************
 * Function to configure the audio codec.
 * @param   iic_index is the i2c index in /dev list.
 * @return  none.
 *****************************************************************************/
void config_audio_codec(void) {
  int iic_index = 1;
  int iic_fd;
  iic_fd = setI2C(iic_index, IIC_SLAVE_ADDR);
  if (iic_fd < 0) {
    pynq_error("config_audio_codec: unable to set I2C %d\n", iic_index);
  }
 
  /*
   * Input path control registers are configured
   * in select_mic and select_line_in
   */
 
  // Mute Mixer1 and Mixer2 here, enable when MIC and Line In used
  write_audio_reg(R4_RECORD_MIXER_LEFT_CONTROL_0, 0x00, iic_fd);
  write_audio_reg(R6_RECORD_MIXER_RIGHT_CONTROL_0, 0x00, iic_fd);
  // Set LDVOL and RDVOL to 21 dB and Enable left and right differential
  write_audio_reg(R8_LEFT_DIFFERENTIAL_INPUT_VOLUME_CONTROL, 0xB3, iic_fd);
  write_audio_reg(R9_RIGHT_DIFFERENTIAL_INPUT_VOLUME_CONTROL, 0xB3, iic_fd);
  // Enable MIC bias
  write_audio_reg(R10_RECORD_MICROPHONE_BIAS_CONTROL, 0x01, iic_fd);
  // Enable ALC control and noise gate
  write_audio_reg(R14_ALC_CONTROL_3, 0x20, iic_fd);
  // Put CODEC in Master mode
  write_audio_reg(R15_SERIAL_PORT_CONTROL_0, 0x01, iic_fd);
  // Enable ADC on both channels, normal polarity and ADC high-pass filter
  write_audio_reg(R19_ADC_CONTROL, 0x33, iic_fd);
  // Mute play back Mixer3 and Mixer4 and enable when output is required
  write_audio_reg(R22_PLAYBACK_MIXER_LEFT_CONTROL_0, 0x00, iic_fd);
  write_audio_reg(R24_PLAYBACK_MIXER_RIGHT_CONTROL_0, 0x00, iic_fd);
  // Mute left input to mixer3 (R23) and right input to mixer4 (R25)
  write_audio_reg(R23_PLAYBACK_MIXER_LEFT_CONTROL_1, 0x00, iic_fd);
  write_audio_reg(R25_PLAYBACK_MIXER_RIGHT_CONTROL_1, 0x00, iic_fd);
  // Mute left and right channels output; enable them when output is needed
  write_audio_reg(R29_PLAYBACK_HEADPHONE_LEFT_VOLUME_CONTROL, 0xE5, iic_fd);
  write_audio_reg(R30_PLAYBACK_HEADPHONE_RIGHT_VOLUME_CONTROL, 0xE5, iic_fd);
  // Enable play back right and left channels
  write_audio_reg(R35_PLAYBACK_POWER_MANAGEMENT, 0x03, iic_fd);
  // Enable DAC for both channels
  write_audio_reg(R36_DAC_CONTROL_0, 0x03, iic_fd);
  // Set SDATA_In to DAC
  write_audio_reg(R58_SERIAL_INPUT_ROUTE_CONTROL, 0x01, iic_fd);
  // Set SDATA_Out to ADC
  write_audio_reg(R59_SERIAL_OUTPUT_ROUTE_CONTROL, 0x01, iic_fd);
  // Enable DSP and DSP Run
  write_audio_reg(R61_DSP_ENABLE, 0x01, iic_fd);
  write_audio_reg(R62_DSP_RUN, 0x01, iic_fd);
  /*
   * Enable Digital Clock Generator 0 and 1.
   * Generator 0 generates sample rates for the ADCs, DACs, and DSP.
   * Generator 1 generates BCLK and LRCLK for the serial port.
   */
  write_audio_reg(R65_CLOCK_ENABLE_0, 0x7F, iic_fd);
  write_audio_reg(R66_CLOCK_ENABLE_1, 0x03, iic_fd);
 
  if (unsetI2C(iic_fd) < 0) {
    pynq_error("config_audio_codec: unable to unset I2C %d\n", iic_index);
  }
}
 
void select_line_in(void) {
  int iic_index = 1;
  int iic_fd;
  iic_fd = setI2C(iic_index, IIC_SLAVE_ADDR);
  if (iic_fd < 0) {
    pynq_error("select_line_in: unable to set I2C %d\n", iic_index);
  }
 
  // Mixer 1  (left channel)
  write_audio_reg(R4_RECORD_MIXER_LEFT_CONTROL_0, 0x01, iic_fd);
  // Enable LAUX (MX1AUXG)
  write_audio_reg(R5_RECORD_MIXER_LEFT_CONTROL_1, 0x07, iic_fd);
 
  // Mixer 2
  write_audio_reg(R6_RECORD_MIXER_RIGHT_CONTROL_0, 0x01, iic_fd);
  // Enable RAUX (MX2AUXG)
  write_audio_reg(R7_RECORD_MIXER_RIGHT_CONTROL_1, 0x07, iic_fd);
 
  if (unsetI2C(iic_fd) < 0) {
    pynq_error("select_line_in: unable to unset I2C %d\n", iic_index);
  }
}
 
void select_mic(void) {
  int iic_index = 1;
  int iic_fd;
  iic_fd = setI2C(iic_index, IIC_SLAVE_ADDR);
  if (iic_fd < 0) {
    pynq_error("select_mic: unable to set I2C %d, ensure sudo chmod 666 "
               "/dev/i2c-1 has been executed\n",
               iic_index);
  }
 
  // Mixer 1 (left channel)
  write_audio_reg(R4_RECORD_MIXER_LEFT_CONTROL_0, 0x01, iic_fd);
  // LDBOOST, set to 20 dB
  write_audio_reg(R5_RECORD_MIXER_LEFT_CONTROL_1, 0x10, iic_fd);
  // LDVOL, set to 21 dB
  write_audio_reg(R8_LEFT_DIFFERENTIAL_INPUT_VOLUME_CONTROL, 0xB3, iic_fd);
 
  // Mixer 2 (right channel)
  write_audio_reg(R6_RECORD_MIXER_RIGHT_CONTROL_0, 0x01, iic_fd);
  // RDBOOST, set to 20 dB
  write_audio_reg(R7_RECORD_MIXER_RIGHT_CONTROL_1, 0x10, iic_fd);
  // RDVOL, set to 21 dB
  write_audio_reg(R9_RIGHT_DIFFERENTIAL_INPUT_VOLUME_CONTROL, 0xB3, iic_fd);
 
  if (unsetI2C(iic_fd) < 0) {
    pynq_error("select_mic: unable to unset I2C %d\n", iic_index);
  }
}
 
void deselect(void) {
  int iic_index = 1;
  int iic_fd;
  iic_fd = setI2C(iic_index, IIC_SLAVE_ADDR);
  if (iic_fd < 0) {
    pynq_error("deselect: unable to set I2C %d\n", iic_index);
  }
 
  // mute mixer 1 in left channel
  write_audio_reg(R4_RECORD_MIXER_LEFT_CONTROL_0, 0x00, iic_fd);
  // mute mixer 2 in right channel
  write_audio_reg(R6_RECORD_MIXER_RIGHT_CONTROL_0, 0x00, iic_fd);
 
  if (unsetI2C(iic_fd) < 0) {
    pynq_error("deselect: unable to unset I2C %d\n", iic_index);
  }
}
 
void audio_bypass(unsigned int audio_mmap_size, unsigned int nsamples,
                  unsigned int volume, int uio_index) {
  if (uio_index > 2) {
    pynq_error("audio_bypass: uio_index outside of range. is %d, should be "
               "below 3. \n",
               uio_index);
  }
  if (volume > 100) {
    pynq_error("audio_bypass: volume outside allowed range. Is %d, should be "
               "below 100 \n",
               volume);
  }
 
  int iic_index = 1;
  int status;
  void *uio_ptr;
  int DataL, DataR;
  int iic_fd;
 
  uio_ptr = setUIO(uio_index, audio_mmap_size);
  iic_fd = setI2C(iic_index, IIC_SLAVE_ADDR);
  if (iic_fd < 0) {
    pynq_error("audio_bypass: unable to set I2C %d, ensure sudo chmod 666 "
               "/dev/i2c-1 has been executed\n",
               iic_index);
  }
 
  // Mute mixer1 and mixer2 input
  write_audio_reg(R23_PLAYBACK_MIXER_LEFT_CONTROL_1, 0x00, iic_fd);
  write_audio_reg(R25_PLAYBACK_MIXER_RIGHT_CONTROL_1, 0x00, iic_fd);
  // Enable Mixer3 and Mixer4
  write_audio_reg(R22_PLAYBACK_MIXER_LEFT_CONTROL_0, 0x21, iic_fd);
  write_audio_reg(R24_PLAYBACK_MIXER_RIGHT_CONTROL_0, 0x41, iic_fd);
 
  unsigned char vol_register = (unsigned char)volume << 2 | 0x3;
  // Enable Left/Right Headphone out
  write_audio_reg(R29_PLAYBACK_HEADPHONE_LEFT_VOLUME_CONTROL, vol_register,
                  iic_fd);
  write_audio_reg(R30_PLAYBACK_HEADPHONE_RIGHT_VOLUME_CONTROL, vol_register,
                  iic_fd);
 
  for (unsigned int i = 0; i < nsamples; i++) {
    // wait for RX data to become available
    do {
      status = *((volatile unsigned *)(((uint8_t *)uio_ptr) + I2S_STATUS_REG));
    } while (status == 0);
    *((volatile unsigned *)(((uint8_t *)uio_ptr) + I2S_STATUS_REG)) =
        0x00000001;
 
    // Read the sample from the input
    DataL = *((volatile int *)(((uint8_t *)uio_ptr) + I2S_DATA_RX_L_REG));
    DataR = *((volatile int *)(((uint8_t *)uio_ptr) + I2S_DATA_RX_R_REG));
 
    // Write the sample to output
    *((volatile int *)(((uint8_t *)uio_ptr) + I2S_DATA_TX_L_REG)) = DataL;
    *((volatile int *)(((uint8_t *)uio_ptr) + I2S_DATA_TX_R_REG)) = DataR;
  }
 
  write_audio_reg(R23_PLAYBACK_MIXER_LEFT_CONTROL_1, 0x00, iic_fd);
  write_audio_reg(R25_PLAYBACK_MIXER_RIGHT_CONTROL_1, 0x00, iic_fd);
  write_audio_reg(R22_PLAYBACK_MIXER_LEFT_CONTROL_0, 0x00, iic_fd);
  write_audio_reg(R24_PLAYBACK_MIXER_RIGHT_CONTROL_0, 0x00, iic_fd);
  write_audio_reg(R29_PLAYBACK_HEADPHONE_LEFT_VOLUME_CONTROL, 0xE5, iic_fd);
  write_audio_reg(R30_PLAYBACK_HEADPHONE_RIGHT_VOLUME_CONTROL, 0xE5, iic_fd);
 
  if (unsetUIO(uio_ptr, audio_mmap_size) < 0) {
    pynq_error("audio_bypass: unable to free UIO %d, ensure sudo chmod 666 "
               "/dev/i2c-1 has been executed\n",
               uio_index);
  }
  if (unsetI2C(iic_fd) < 0) {
    pynq_error("audio_bypass: unable to unset I2C %d, ensure sudo chmod 666 "
               "/dev/i2c-1 has been executed\n",
               iic_index);
  }
}
 
void audio_record(unsigned int audio_mmap_size, unsigned int *BufAddr,
                  unsigned int nsamples, int uio_index) {
  if (uio_index > 2) {
    pynq_error("audio_record: uio_index outside of range. is %d, should be "
               "below 3. \n",
               uio_index);
  }
  int iic_index = 1;
  unsigned int i, status;
  void *uio_ptr;
  int DataL, DataR;
  int iic_fd;
 
  uio_ptr = setUIO(uio_index, audio_mmap_size);
  iic_fd = setI2C(iic_index, IIC_SLAVE_ADDR);
  if (iic_fd < 0) {
    pynq_error("audio_record: unable to set I2C %d, ensure sudo chmod 666 "
               "/dev/i2c-1 has been executed\n",
               iic_index);
  }
 
  for (i = 0; i < nsamples; i++) {
    do {
      status = *((volatile unsigned *)(((uint8_t *)uio_ptr) + I2S_STATUS_REG));
    } while (status == 0);
    *((volatile unsigned *)(((uint8_t *)uio_ptr) + I2S_STATUS_REG)) =
        0x00000001;
 
    // Read the sample from the input
    DataL = *((volatile int *)(((uint8_t *)uio_ptr) + I2S_DATA_RX_L_REG));
    DataR = *((volatile int *)(((uint8_t *)uio_ptr) + I2S_DATA_RX_R_REG));
 
    // Write the sample into memory
    *(BufAddr + 2 * i) = DataL;
    *(BufAddr + 2 * i + 1) = DataR;
  }
 
  if (unsetUIO(uio_ptr, audio_mmap_size) < 0) {
    pynq_error("audio_record: unable to free UIO %d, ensure sudo chmod 666 "
               "/dev/i2c-1 has been executed\n",
               uio_index);
  }
  if (unsetI2C(iic_fd) < 0) {
    pynq_error("audio_record: unable to unset I2C %d, ensure sudo chmod 666 "
               "/dev/i2c-1 has been executed\n",
               iic_index);
  }
}
 
void audio_play(unsigned int audio_mmap_size, unsigned int *BufAddr,
                unsigned int nsamples, unsigned int volume, int uio_index) {
  if (uio_index > 2) {
    pynq_error(
        "audio_play: uio_index outside of range. is %d, should be below 3. \n",
        uio_index);
  }
  if (volume > 100) {
    pynq_error("audio_play: volume outside allowed range. Is %d, should be "
               "below 100 \n",
               volume);
  }
  int iic_index = 1;
  unsigned int i, status;
  void *uio_ptr;
  int DataL, DataR;
  int iic_fd;
 
  uio_ptr = setUIO(uio_index, audio_mmap_size);
  iic_fd = setI2C(iic_index, IIC_SLAVE_ADDR);
  if (iic_fd < 0) {
    pynq_error("audio_play: unable to set I2C %d, ensure sudo chmod 666 "
               "/dev/i2c-1 has been executed\n",
               iic_index);
  }
 
  // Unmute left and right DAC, enable Mixer3 and Mixer4
  write_audio_reg(R22_PLAYBACK_MIXER_LEFT_CONTROL_0, 0x21, iic_fd);
  write_audio_reg(R24_PLAYBACK_MIXER_RIGHT_CONTROL_0, 0x41, iic_fd);
 
  unsigned char vol_register = (unsigned char)volume << 2 | 0x3;
  // Enable Left/Right Headphone out
  write_audio_reg(R29_PLAYBACK_HEADPHONE_LEFT_VOLUME_CONTROL, vol_register,
                  iic_fd);
  write_audio_reg(R30_PLAYBACK_HEADPHONE_RIGHT_VOLUME_CONTROL, vol_register,
                  iic_fd);
 
  for (i = 0; i < nsamples; i++) {
    do {
      status = *((volatile unsigned *)(((uint8_t *)uio_ptr) + I2S_STATUS_REG));
    } while (status == 0);
    *((volatile unsigned *)(((uint8_t *)uio_ptr) + I2S_STATUS_REG)) =
        0x00000001;
 
    // Read the sample from memory
    DataL = *(BufAddr + 2 * i);
    DataR = *(BufAddr + 2 * i + 1);
 
    // Write the sample to output
    *((volatile int *)(((uint8_t *)uio_ptr) + I2S_DATA_TX_L_REG)) = DataL;
    *((volatile int *)(((uint8_t *)uio_ptr) + I2S_DATA_TX_R_REG)) = DataR;
  }
 
  // Mute left and right DAC
  write_audio_reg(R22_PLAYBACK_MIXER_LEFT_CONTROL_0, 0x01, iic_fd);
  write_audio_reg(R24_PLAYBACK_MIXER_RIGHT_CONTROL_0, 0x01, iic_fd);
  // Mute left input to mixer3 (R23) and right input to mixer4 (R25)
  write_audio_reg(R23_PLAYBACK_MIXER_LEFT_CONTROL_1, 0x00, iic_fd);
  write_audio_reg(R25_PLAYBACK_MIXER_RIGHT_CONTROL_1, 0x00, iic_fd);
 
  if (unsetUIO(uio_ptr, audio_mmap_size) < 0) {
    pynq_error("audio_play: unable to free UIO %d, ensure sudo chmod 666 "
               "/dev/i2c-1 has been executed\n",
               uio_index);
  }
  if (unsetI2C(iic_fd) < 0) {
    pynq_error("audio_play: unable to unset I2C %d, ensure sudo chmod 666 "
               "/dev/i2c-1 has been executed\n",
               iic_index);
  }
}
 
void audio_repeat_play(unsigned int audio_mmap_size, unsigned int *BufAddr,
                       unsigned int nsamples, unsigned int volume,
                       unsigned int repetitions) {
  if (volume > 100) {
    pynq_error("audio_repeat_play: volume outside allowed range. Is %d, should "
               "be below 100 \n",
               volume);
  }
  int iic_index = 1;
  unsigned int i, status;
  void *uio_ptr;
  int DataL, DataR;
  int iic_fd;
 
  uio_ptr = setUIO(0, audio_mmap_size);
  iic_fd = setI2C(iic_index, IIC_SLAVE_ADDR);
  if (iic_fd < 0) {
    pynq_error("audio_repeat_play: unable to set I2C %d, ensure sudo chmod 666 "
               "/dev/i2c-1 has been executed\n",
               iic_index);
  }
 
  // Unmute left and right DAC, enable Mixer3 and Mixer4
  write_audio_reg(R22_PLAYBACK_MIXER_LEFT_CONTROL_0, 0x21, iic_fd);
  write_audio_reg(R24_PLAYBACK_MIXER_RIGHT_CONTROL_0, 0x41, iic_fd);
 
  unsigned char vol_register = (unsigned char)volume << 2 | 0x3;
  // Enable Left/Right Headphone out
  write_audio_reg(R29_PLAYBACK_HEADPHONE_LEFT_VOLUME_CONTROL, vol_register,
                  iic_fd);
  write_audio_reg(R30_PLAYBACK_HEADPHONE_RIGHT_VOLUME_CONTROL, vol_register,
                  iic_fd);
 
  for (unsigned int repeat = 0; repeat < repetitions; repeat++) {
    for (i = 0; i < nsamples; i++) {
      do {
        status =
            *((volatile unsigned *)(((uint8_t *)uio_ptr) + I2S_STATUS_REG));
      } while (status == 0);
      *((volatile unsigned *)(((uint8_t *)uio_ptr) + I2S_STATUS_REG)) =
          0x00000001;
 
      // Read the sample from memory
      DataL = *(BufAddr + 2 * i);
      DataR = *(BufAddr + 2 * i + 1);
 
      // Write the sample to output
      *((volatile int *)(((uint8_t *)uio_ptr) + I2S_DATA_TX_L_REG)) = DataL;
      *((volatile int *)(((uint8_t *)uio_ptr) + I2S_DATA_TX_R_REG)) = DataR;
    }
  }
  // Mute left and right DAC
  write_audio_reg(R22_PLAYBACK_MIXER_LEFT_CONTROL_0, 0x01, iic_fd);
  write_audio_reg(R24_PLAYBACK_MIXER_RIGHT_CONTROL_0, 0x01, iic_fd);
  // Mute left input to mixer3 (R23) and right input to mixer4 (R25)
  write_audio_reg(R23_PLAYBACK_MIXER_LEFT_CONTROL_1, 0x00, iic_fd);
  write_audio_reg(R25_PLAYBACK_MIXER_RIGHT_CONTROL_1, 0x00, iic_fd);
 
  if (unsetUIO(uio_ptr, audio_mmap_size) < 0) {
    pynq_error("audio_repeat_play: unable to free UIO %d\n", 0);
  }
  if (unsetI2C(iic_fd) < 0) {
    pynq_error("audio_repeat_play: unable to unset I2C %d, ensure sudo chmod "
               "666 /dev/i2c-1 has been executed\n",
               iic_index);
  }
}
 
void audio_generate_tone(unsigned int frequency, uint32_t time_ms,
                         unsigned int volume) {
 
  if (frequency < 10) {
    pynq_error("audio_generate_tone: frequency should be 10 or higher, "
               "frequency is: %d\n",
               frequency);
  }
  if (volume > 100) {
    pynq_error("audio_generate_tone: volume outside allowed range. Is %d, "
               "should be below 100 \n",
               volume);
  }
  double period = 1 / ((double)(frequency));
  unsigned int samplesPerPeriod = (int)(SAMPLE_RATE * period);
  double time_s = ((double)(time_ms)) / 1000;
  int totalPeriods = (int)(time_s / period); // Number of times one period must
                                             // be played to play for time_ms
 
  uint32_t audioBuffer[16 * 1024 + 1] = {0};
  unsigned int i, status;
 
  for (i = 0; i < samplesPerPeriod; i++) {
    double t = (double)i / SAMPLE_RATE;
    double value = sin(6.28318531 * frequency * t); // 6.28... = 2pi
    value = value + 1;
    value = value * 16000;
    audioBuffer[2 * i] = (uint32_t)value;
    audioBuffer[2 * i + 1] = (uint32_t)value;
  }
 
  unsigned int audio_mmap_size = 64 * 1024;
  unsigned int *BufAddr = audioBuffer;
  int iic_index = 1;
  void *uio_ptr;
  int DataL, DataR;
  int iic_fd;
 
  uio_ptr = setUIO(0, audio_mmap_size);
  iic_fd = setI2C(iic_index, IIC_SLAVE_ADDR);
  if (iic_fd < 0) {
    pynq_error("audio_generate_tone: unable to set I2C %d, ensure sudo chmod "
               "666 /dev/i2c-1 has been executed\n",
               iic_index);
  }
 
  // Unmute left and right DAC, enable Mixer3 and Mixer4
  write_audio_reg(R22_PLAYBACK_MIXER_LEFT_CONTROL_0, 0x21, iic_fd);
  write_audio_reg(R24_PLAYBACK_MIXER_RIGHT_CONTROL_0, 0x41, iic_fd);
 
  unsigned char vol_register = (unsigned char)volume << 2 | 0x3;
  // Enable Left/Right Headphone out
  write_audio_reg(R29_PLAYBACK_HEADPHONE_LEFT_VOLUME_CONTROL, vol_register,
                  iic_fd);
  write_audio_reg(R30_PLAYBACK_HEADPHONE_RIGHT_VOLUME_CONTROL, vol_register,
                  iic_fd);
 
  for (int period = 0; period < totalPeriods; period++) {
    for (i = 0; i < samplesPerPeriod; i++) {
      do {
        status =
            *((volatile unsigned *)(((uint8_t *)uio_ptr) + I2S_STATUS_REG));
      } while (status == 0);
      *((volatile unsigned *)(((uint8_t *)uio_ptr) + I2S_STATUS_REG)) =
          0x00000001;
 
      // Read the sample from memory
      DataL = *(BufAddr + 2 * i);
      DataR = *(BufAddr + 2 * i + 1);
 
      // Write the sample to output
      *((volatile int *)(((uint8_t *)uio_ptr) + I2S_DATA_TX_L_REG)) = DataL;
      *((volatile int *)(((uint8_t *)uio_ptr) + I2S_DATA_TX_R_REG)) = DataR;
    }
  }
  // Mute left and right DAC
  write_audio_reg(R22_PLAYBACK_MIXER_LEFT_CONTROL_0, 0x01, iic_fd);
  write_audio_reg(R24_PLAYBACK_MIXER_RIGHT_CONTROL_0, 0x01, iic_fd);
  // Mute left input to mixer3 (R23) and right input to mixer4 (R25)
  write_audio_reg(R23_PLAYBACK_MIXER_LEFT_CONTROL_1, 0x00, iic_fd);
  write_audio_reg(R25_PLAYBACK_MIXER_RIGHT_CONTROL_1, 0x00, iic_fd);
 
  if (unsetUIO(uio_ptr, audio_mmap_size) < 0) {
    pynq_error("audio_generate_tone: unable to free UIO %d, ensure sudo chmod "
               "666 /dev/i2c-1 has been executed\n",
               0);
  }
  if (unsetI2C(iic_fd) < 0) {
    pynq_error("audio_generate_tone: unable to unset I2C %d, ensure has been "
               "executed\n",
               iic_index);
  }
}