IMX93 with WM8962 without SAI MCLK

baguiam · ‎10-30-2025

Hello All,

I’m currently facing difficulties getting IMX93 working with WM8962 codec.

We are working in BareMetal ThreadX application, and I’m using the fsl_wm8962 driver directly. Currently our hardware has a SAI_MCLK line being generated externally by oscillator.

Given this last detail, I’m not sure what is the right SAI and wm8962 configuration, for this scenario.

Below I will share one of testing configuration not working.

Pinmux Configuration:

static void SAI1_InitPins(void)

{

IOMUXC_SetPinMux(IOMUXC_PAD_SAI1_TXD0__SAI1_TX_DATA00, 0U);

IOMUXC_SetPinConfig(IOMUXC_PAD_SAI1_TXD0__SAI1_TX_DATA00,

IOMUXC_PAD_DSE(15U));

IOMUXC_SetPinMux(IOMUXC_PAD_SAI1_RXD0__SAI1_RX_DATA00, 0U);

IOMUXC_SetPinConfig(IOMUXC_PAD_SAI1_RXD0__SAI1_RX_DATA00,

IOMUXC_PAD_DSE(15U));

IOMUXC_SetPinMux(IOMUXC_PAD_SAI1_TXC__SAI1_TX_BCLK, 0U);

IOMUXC_SetPinConfig(IOMUXC_PAD_SAI1_TXC__SAI1_TX_BCLK,

IOMUXC_PAD_DSE(15U));

IOMUXC_SetPinMux(IOMUXC_PAD_SAI1_TXFS__SAI1_TX_SYNC, 0U);

IOMUXC_SetPinConfig(IOMUXC_PAD_SAI1_TXFS__SAI1_TX_SYNC,

IOMUXC_PAD_DSE(15U));

/* MCLK is generated by external oscilator */

/* IOMUXC_SetPinMux(IOMUXC_PAD_UART2_RXD__SAI1_MCLK, 0U);

IOMUXC_SetPinConfig(IOMUXC_PAD_UART2_RXD__SAI1_MCLK,

IOMUXC_PAD_DSE(15U)); */

}

Board Configuration:

static void BOARD_AudioClockSetup(void)

{

/*

* AUDIOPLL1/AUDIOPLL1OUT

*

* VCO = (24MHz / rdiv) * (mfi + (mfn / mfd)) = 3,932,160,000 Hz

* Output = VCO / odiv = 393.216 MHz

*/

const fracn_pll_init_t g_audioPllCfg = {

.rdiv = 1,

.mfi = 163,

.mfn = 84,

.mfd = 100,

.odiv = 10

};

/* clang-format off */

const clock_root_config_t lpi2cClkCfg = {

.clockOff = false,

.mux = 0, // 24MHz oscillator source

.div = 1

};

const clock_root_config_t saiClkCfg = {

.clockOff = false,

.mux = 1, // select audiopll1out source(393216000 Hz)

.div = 32 // output 12288000 Hz

//.div = 16 // output 24576000 Hz

};

/* 250MHz DMA clock */

const clock_root_config_t dmaClkCfg = {

.clockOff = false,

.mux = kCLOCK_WAKEUPAXI_ClockRoot_MuxSysPll1Pfd0, // 1000MHz // For edma3 this is different ?

.div = 4

};

// Not Needed, external 24MHz

sai_master_clock_t saiMasterCfg = {

.mclkOutputEnable = false,

};

/* clang-format on */

/* ROM has already initialized PLL */

CLOCK_PllInit(AUDIOPLL, &g_audioPllCfg);

/*I2C */

CLOCK_SetRootClock(kCLOCK_Root_Lpi2c2, &lpi2cClkCfg);

CLOCK_EnableClock(kCLOCK_Lpi2c2);

/* SAI1 Clock Config */

CLOCK_SetRootClock(kCLOCK_Root_Sai1, &saiClkCfg);

CLOCK_EnableClock(kCLOCK_Sai1);

/* Edma Clock Config */

CLOCK_SetRootClock(kCLOCK_Root_WakeupAxi, &dmaClkCfg); // Check this

CLOCK_EnableClock(kCLOCK_Edma1);

//saiMasterCfg.mclkSourceClkHz = CLOCK_GetIpFreq(kCLOCK_Root_Sai1); /* setup source clock for MCLK */

//saiMasterCfg.mclkHz = 24000000U; /* setup target clock of MCLK */

SAI_SetMasterClockConfig(SAI1, &saiMasterCfg);

}

Init SAI:

void InitAudio_SAI(void)

{

/* SAI init */

SAI_Init(SAI1);

SAI_TransferTxCreateHandle(SAI1, &txHandle, SAI_callback, NULL);

/* I2S mode configurations */

SAI_GetClassicI2SConfig(&saiConfig, kSAI_WordWidth16bits, kSAI_Stereo, kSAI_Channel0Mask);

saiConfig.syncMode = kSAI_ModeAsync;

saiConfig.masterSlave = kSAI_Slave;

SAI_TransferTxSetConfig(SAI1, &txHandle, &saiConfig);

/* set bit clock divider */

SAI_TxSetBitClockRate(SAI1, 12288000U, kSAI_SampleRate16KHz, kSAI_WordWidth16bits, 2U);

intCtrlHandlerRegister(SAI1_IRQn,(void*)SAI1_DriverIRQHandler,OS_IRQ_PRIO_MAX);

EnableIRQ(SAI1_IRQn);

}

Init Codec and Config:

static wm8962_config_t wm8962Config_16 = {

.i2cConfig = {.codecI2CInstance = BOARD_CODEC_I2C_INSTANCE},

.route =

{

.enableLoopBack = false,

.leftInputPGASource = kWM8962_InputPGASourceInput1,

.rightInputPGASource = kWM8962_InputPGASourceInput1,

.leftInputMixerSource = kWM8962_InputMixerSourceInputPGA,

.rightInputMixerSource = kWM8962_InputMixerSourceInputPGA,

.leftSpeakerPGASource = kWM8962_OutputPGASourceDAC,

.rightSpeakerPGASource = kWM8962_OutputPGASourceDAC,

.leftSpeakerMixerSource = kWM8962_OutputMixerSourceLeftDAC,

.rightSpeakerMixerSource = kWM8962_OutputMixerSourceRightDAC,

.leftHeadphonePGASource = kWM8962_OutputPGASourceDAC,

.rightHeadphonePGASource = kWM8962_OutputPGASourceDAC,

.leftHeadphoneMixerSource = kWM8962_OutputMixerSourceLeftDAC,

.rightHeadphoneMixerSource = kWM8962_OutputMixerSourceRightDAC

},

.slaveAddress = WM8962_I2C_ADDR,

.bus = kWM8962_BusI2S,

.format = {.sampleRate = kWM8962_AudioSampleRate16KHz, .bitWidth = kWM8962_AudioBitWidth16bit},

.fllClock =

{

.fllClockSource = kWM8962_FLLClkSourceMCLK,

.fllReferenceClockFreq = 24000000U,

.fllOutputFreq = 12288000U,

},

//.sysclkSource = kWM8962_SysClkSourceMclk, /* use MCLK pin as sysclk's source */

.sysclkSource = kWM8962_SysClkSourceFLL,

/* sai running as master mode, so codec running as master just have PLL config by codec driver */

.masterSlave = true,

};

status_t Init_Codec(void)

{

wm8962Config_16.i2cConfig.codecI2CSourceClock = CLOCK_GetIpFreq(kCLOCK_Root_Lpi2c2);

wm8962Config_16.format.mclk_HZ = 24000000U;

status_t result = WM8962_Init(&codecHandle,&wm8962Config_16);

if (result != kStatus_Success) {

/* Handle initialization error */

arm64_lowputs("Error Initializing WM8962!\r\n");

return result;

}

else

{

arm64_lowputs("WM8962_Init Successfull!\r\n");

}

#if(1)

// Now configure as slave for actual operation

WM8962_ModifyReg(&codecHandle, WM8962_IFACE0, 1U << 6U, 0U << 6U); // Clear MS bit (slave mode)

arm64_lowputs("WM8962_Init Successful with FLL in slave mode!\r\n");

#endif

PlaySound:

/* xfer structure */

temp = (uint32_t)music;

xfer.data = (uint8_t *)temp;

xfer.dataSize = MUSIC_LEN;

SAI_TransferSendNonBlocking(SAI1, &txHandle, &xfer);

/* Wait until finished */

while (isFinished != true)

{

//tx_thread_sleep(1);

}

arm64_lowputs("\n\r SAI example finished!\n\r ");

Please if you could support with examples of such a configuration I would appreciate a lot.

Manuel_Salas · ‎10-30-2025

Hello @baguiam

I hope you are doing very well.

Unfortunately, there are not examples, but looking at your code, there are many configurations that can be wrong and failing.

First:

.fllClockSource = kWM8962_FLLClkSourceMCLK

You are configuring the FLL to take MCLK as reference clock source.

According to the WM8962's Datasheet, you can select between MCLK, BCLK and Internal OSC:

Then, if you're not using MCLK, SAI must be master to generate BCLK and FSYNC for the codec:

saiConfig.masterSlave = kSAI_Master;

And codec as slave as you did:

WM8962_IFACE0

Please try with those configurations.

If you are having more issues after those configurations, please share your schematic related to the CODEC.

Best regards,

Salas.

baguiam · ‎10-31-2025

Hello,

Thank you for answering and trying to help. It's much appreciated.

saiConfig.masterSlave = kSAI_Master;

Sorry that was an error of the copy-paste. i Tried a lot of variations.

So with master i can see a short period of bCLK and ADCDAT. But nothing from DACDAT with my playing sound data. Also the interrupts seems not being trigged.

Manuel_Salas · ‎10-31-2025

Hello @baguiam

So, please share the project with the last updates.

Then I can check it.

Best regards,

Salas.

baguiam · ‎11-05-2025

That's the only error i made above.

Pinmux Configuration:

static void SAI1_InitPins(void)

{

IOMUXC_SetPinMux(IOMUXC_PAD_SAI1_TXD0__SAI1_TX_DATA00, 0U);

IOMUXC_SetPinConfig(IOMUXC_PAD_SAI1_TXD0__SAI1_TX_DATA00,

IOMUXC_PAD_DSE(15U));

IOMUXC_SetPinMux(IOMUXC_PAD_SAI1_RXD0__SAI1_RX_DATA00, 0U);

IOMUXC_SetPinConfig(IOMUXC_PAD_SAI1_RXD0__SAI1_RX_DATA00,

IOMUXC_PAD_DSE(15U));

IOMUXC_SetPinMux(IOMUXC_PAD_SAI1_TXC__SAI1_TX_BCLK, 0U);

IOMUXC_SetPinConfig(IOMUXC_PAD_SAI1_TXC__SAI1_TX_BCLK,

IOMUXC_PAD_DSE(15U));

IOMUXC_SetPinMux(IOMUXC_PAD_SAI1_TXFS__SAI1_TX_SYNC, 0U);

IOMUXC_SetPinConfig(IOMUXC_PAD_SAI1_TXFS__SAI1_TX_SYNC,

IOMUXC_PAD_DSE(15U));

/* MCLK is generated by external oscilator */

/* IOMUXC_SetPinMux(IOMUXC_PAD_UART2_RXD__SAI1_MCLK, 0U);

IOMUXC_SetPinConfig(IOMUXC_PAD_UART2_RXD__SAI1_MCLK,

IOMUXC_PAD_DSE(15U)); */

}

Board Configuration:

static void BOARD_AudioClockSetup(void)

{

/*

* AUDIOPLL1/AUDIOPLL1OUT

*

* VCO = (24MHz / rdiv) * (mfi + (mfn / mfd)) = 3,932,160,000 Hz

* Output = VCO / odiv = 393.216 MHz

*/

const fracn_pll_init_t g_audioPllCfg = {

.rdiv = 1,

.mfi = 163,

.mfn = 84,

.mfd = 100,

.odiv = 10

};

/* clang-format off */

const clock_root_config_t lpi2cClkCfg = {

.clockOff = false,

.mux = 0, // 24MHz oscillator source

.div = 1

};

const clock_root_config_t saiClkCfg = {

.clockOff = false,

.mux = 1, // select audiopll1out source(393216000 Hz)

.div = 32 // output 12288000 Hz

//.div = 16 // output 24576000 Hz

};

/* 250MHz DMA clock */

const clock_root_config_t dmaClkCfg = {

.clockOff = false,

.mux = kCLOCK_WAKEUPAXI_ClockRoot_MuxSysPll1Pfd0, // 1000MHz // For edma3 this is different ?

.div = 4

};

// Not Needed, external 24MHz

sai_master_clock_t saiMasterCfg = {

.mclkOutputEnable = false,

};

/* clang-format on */

/* ROM has already initialized PLL */

CLOCK_PllInit(AUDIOPLL, &g_audioPllCfg);

/*I2C */

CLOCK_SetRootClock(kCLOCK_Root_Lpi2c2, &lpi2cClkCfg);

CLOCK_EnableClock(kCLOCK_Lpi2c2);

/* SAI1 Clock Config */

CLOCK_SetRootClock(kCLOCK_Root_Sai1, &saiClkCfg);

CLOCK_EnableClock(kCLOCK_Sai1);

/* Edma Clock Config */

CLOCK_SetRootClock(kCLOCK_Root_WakeupAxi, &dmaClkCfg); // Check this

CLOCK_EnableClock(kCLOCK_Edma1);

//saiMasterCfg.mclkSourceClkHz = CLOCK_GetIpFreq(kCLOCK_Root_Sai1); /* setup source clock for MCLK */

//saiMasterCfg.mclkHz = 24000000U; /* setup target clock of MCLK */

SAI_SetMasterClockConfig(SAI1, &saiMasterCfg);

}

Init SAI:

void InitAudio_SAI(void)

{

/* SAI init */

SAI_Init(SAI1);

SAI_TransferTxCreateHandle(SAI1, &txHandle, SAI_callback, NULL);

/* I2S mode configurations */

SAI_GetClassicI2SConfig(&saiConfig, kSAI_WordWidth16bits, kSAI_Stereo, kSAI_Channel0Mask);

saiConfig.syncMode = kSAI_ModeAsync;

saiConfig.masterSlave = kSAI_Master;

SAI_TransferTxSetConfig(SAI1, &txHandle, &saiConfig);

/* set bit clock divider */

SAI_TxSetBitClockRate(SAI1, 12288000U, kSAI_SampleRate16KHz, kSAI_WordWidth16bits, 2U);

intCtrlHandlerRegister(SAI1_IRQn,(void*)SAI1_DriverIRQHandler,OS_IRQ_PRIO_MAX);

EnableIRQ(SAI1_IRQn);

}

Init Codec and Config:

static wm8962_config_t wm8962Config_16 = {

.i2cConfig = {.codecI2CInstance = BOARD_CODEC_I2C_INSTANCE},

.route =

{

.enableLoopBack = false,

.leftInputPGASource = kWM8962_InputPGASourceInput1,

.rightInputPGASource = kWM8962_InputPGASourceInput1,

.leftInputMixerSource = kWM8962_InputMixerSourceInputPGA,

.rightInputMixerSource = kWM8962_InputMixerSourceInputPGA,

.leftSpeakerPGASource = kWM8962_OutputPGASourceDAC,

.rightSpeakerPGASource = kWM8962_OutputPGASourceDAC,

.leftSpeakerMixerSource = kWM8962_OutputMixerSourceLeftDAC,

.rightSpeakerMixerSource = kWM8962_OutputMixerSourceRightDAC,

.leftHeadphonePGASource = kWM8962_OutputPGASourceDAC,

.rightHeadphonePGASource = kWM8962_OutputPGASourceDAC,

.leftHeadphoneMixerSource = kWM8962_OutputMixerSourceLeftDAC,

.rightHeadphoneMixerSource = kWM8962_OutputMixerSourceRightDAC

},

.slaveAddress = WM8962_I2C_ADDR,

.bus = kWM8962_BusI2S,

.format = {.sampleRate = kWM8962_AudioSampleRate16KHz, .bitWidth = kWM8962_AudioBitWidth16bit},

.fllClock =

{

.fllClockSource = kWM8962_FLLClkSourceMCLK,

.fllReferenceClockFreq = 24000000U,

.fllOutputFreq = 12288000U,

},

//.sysclkSource = kWM8962_SysClkSourceMclk, /* use MCLK pin as sysclk's source */

.sysclkSource = kWM8962_SysClkSourceFLL,

/* sai running as master mode, so codec running as master just have PLL config by codec driver */

.masterSlave = true,

};

status_t Init_Codec(void)

{

wm8962Config_16.i2cConfig.codecI2CSourceClock = CLOCK_GetIpFreq(kCLOCK_Root_Lpi2c2);

wm8962Config_16.format.mclk_HZ = 24000000U;

status_t result = WM8962_Init(&codecHandle,&wm8962Config_16);

if (result != kStatus_Success) {

/* Handle initialization error */

arm64_lowputs("Error Initializing WM8962!\r\n");

return result;

}

else

{

arm64_lowputs("WM8962_Init Successfull!\r\n");

}

#if(1)

// Now configure as slave for actual operation

WM8962_ModifyReg(&codecHandle, WM8962_IFACE0, 1U << 6U, 0U << 6U); // Clear MS bit (slave mode)

arm64_lowputs("WM8962_Init Successful with FLL in slave mode!\r\n");

#endif

PlaySound:

/* xfer structure */

temp = (uint32_t)music;

xfer.data = (uint8_t *)temp;

xfer.dataSize = MUSIC_LEN;

SAI_TransferSendNonBlocking(SAI1, &txHandle, &xfer);

/* Wait until finished */

while (isFinished != true)

{

//tx_thread_sleep(1);

}

arm64_lowputs("\n\r SAI example finished!\n\r ");