SPDIF_Tx.c

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/*
 * SPDIF_Tx.c
 *
 *  Created on: May 29, 2016
 *      Author: Torsten
 */

#include "main.h"
#include "AudioPlayer.h"

/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/

SAI_HandleTypeDef            spdiftxhsai;

uint8_t SPDIF_TX_buf[AUDIO_OUT_BUFFER_SIZE];

void SPDIF_Tx_Init(void)
{
    /* Configure SAI in SPDIF-Tx Mode */
    spdiftxhsai.Instance           = SAI2_Block_A;
    spdiftxhsai.Init.AudioMode      = SAI_MODEMASTER_TX;
    spdiftxhsai.Init.Synchro        = SAI_ASYNCHRONOUS;
    spdiftxhsai.Init.SynchroExt     = SAI_SYNCEXT_DISABLE;
    spdiftxhsai.Init.OutputDrive    = SAI_OUTPUTDRIVE_DISABLE;
    spdiftxhsai.Init.NoDivider      = SAI_MASTERDIVIDER_ENABLE;
    spdiftxhsai.Init.FIFOThreshold  = SAI_FIFOTHRESHOLD_EMPTY;
    spdiftxhsai.Init.AudioFrequency = SAI_AUDIO_FREQUENCY_96K; //WHY????
    spdiftxhsai.Init.Mckdiv         = 0;
    spdiftxhsai.Init.MonoStereoMode = SAI_STEREOMODE;
    spdiftxhsai.Init.CompandingMode = SAI_NOCOMPANDING;
    spdiftxhsai.Init.TriState       = SAI_OUTPUT_NOTRELEASED;
    spdiftxhsai.Init.Protocol       = SAI_SPDIF_PROTOCOL;
    spdiftxhsai.Init.DataSize       = SAI_DATASIZE_16;
    spdiftxhsai.Init.FirstBit       = SAI_FIRSTBIT_MSB;
    spdiftxhsai.Init.ClockStrobing  = SAI_CLOCKSTROBING_FALLINGEDGE;

    spdiftxhsai.FrameInit.FrameLength       = 64;
    spdiftxhsai.FrameInit.ActiveFrameLength = 32;
    spdiftxhsai.FrameInit.FSDefinition      = SAI_FS_STARTFRAME;
    spdiftxhsai.FrameInit.FSPolarity        = SAI_FS_ACTIVE_LOW;
    spdiftxhsai.FrameInit.FSOffset          = SAI_FS_FIRSTBIT;

    spdiftxhsai.SlotInit.FirstBitOffset = 0;
    spdiftxhsai.SlotInit.SlotSize       = SAI_SLOTSIZE_DATASIZE;
    spdiftxhsai.SlotInit.SlotNumber     = 4;
    spdiftxhsai.SlotInit.SlotActive     = 0x0000000F; //SAI_SLOTACTIVE_ALL;

      if(HAL_SAI_Init(&spdiftxhsai)!= HAL_OK )
      {
        return;
      }
}

void SPDIF_Tx_Start(void)
{
    /* Start transmission (DMA mode) */
    HAL_SAI_Transmit_DMA(&spdiftxhsai, (uint8_t *)SPDIF_TX_buf, sizeof(SPDIF_TX_buf) / sizeof(uint16_t));
}

static void SPDIF_Tx_CpyBuf(uint8_t *dst, uint8_t *src, int len)
{
    while (len)
    {
        *dst++ = *(src + 1);
        *dst++ = *(src + 0);
        src += 2;
        len -= 2;
    }
}

void SPDIF_TX_TransferComplete_CallBack(void)
{
    uint8_t *buf, *outBuf;
    int bufLen;

    bufLen = AUDIO_PLAYER_GetBuffer(&buf);

    if (AUDIO_PLAYER_GetState() == 0)
        outBuf = buf;
    else
        outBuf = buf + bufLen / 2;

    SPDIF_Tx_CpyBuf(&SPDIF_TX_buf[AUDIO_TOTAL_BUF_SIZE], outBuf, bufLen / 2);
}

void SPDIF_TX_HalfTransfer_CallBack(void)
{
    uint8_t *buf, *outBuf;
    int bufLen;

    bufLen = AUDIO_PLAYER_GetBuffer(&buf);

    if (AUDIO_PLAYER_GetState() == 0)
        outBuf = buf;
    else
        outBuf = buf + bufLen / 2;

    SPDIF_Tx_CpyBuf(&SPDIF_TX_buf[0], outBuf, bufLen / 2);
}