SAI SDMA Driver

Overview

Data Structures
struct	sai_sdma_handle_t
	SAI DMA transfer handle, users should not touch the content of the handle. More...

Typedefs
typedef void(*	sai_sdma_callback_t )(I2S_Type *base, sai_sdma_handle_t *handle, status_t status, void *userData)
	SAI SDMA transfer callback function for finish and error.

SDMA Transactional
void	SAI_TransferTxCreateHandleSDMA (I2S_Type *base, sai_sdma_handle_t *handle, sai_sdma_callback_t callback, void *userData, sdma_handle_t *dmaHandle, uint32_t eventSource)
	Initializes the SAI SDMA handle. More...
void	SAI_TransferRxCreateHandleSDMA (I2S_Type *base, sai_sdma_handle_t *handle, sai_sdma_callback_t callback, void *userData, sdma_handle_t *dmaHandle, uint32_t eventSource)
	Initializes the SAI Rx SDMA handle. More...
void	SAI_TransferTxSetFormatSDMA (I2S_Type *base, sai_sdma_handle_t *handle, sai_transfer_format_t *format, uint32_t mclkSourceClockHz, uint32_t bclkSourceClockHz)
	Configures the SAI Tx audio format. More...
void	SAI_TransferRxSetFormatSDMA (I2S_Type *base, sai_sdma_handle_t *handle, sai_transfer_format_t *format, uint32_t mclkSourceClockHz, uint32_t bclkSourceClockHz)
	Configures the SAI Rx audio format. More...
status_t	SAI_TransferSendSDMA (I2S_Type *base, sai_sdma_handle_t *handle, sai_transfer_t *xfer)
	Performs a non-blocking SAI transfer using DMA. More...
status_t	SAI_TransferReceiveSDMA (I2S_Type *base, sai_sdma_handle_t *handle, sai_transfer_t *xfer)
	Performs a non-blocking SAI receive using SDMA. More...
void	SAI_TransferAbortSendSDMA (I2S_Type *base, sai_sdma_handle_t *handle)
	Aborts a SAI transfer using SDMA. More...
void	SAI_TransferAbortReceiveSDMA (I2S_Type *base, sai_sdma_handle_t *handle)
	Aborts a SAI receive using SDMA. More...

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Data Structure Documentation

struct _sai_sdma_handle

Data Fields
sdma_handle_t *	dmaHandle
	DMA handler for SAI send.
uint8_t	bytesPerFrame
	Bytes in a frame.
uint8_t	channel
	Which data channel.
uint8_t	count
	The transfer data count in a DMA request.
uint32_t	state
	Internal state for SAI SDMA transfer.
uint32_t	eventSource
	SAI event source number.
sai_sdma_callback_t	callback
	Callback for users while transfer finish or error occurs.
void *	userData
	User callback parameter.
sdma_buffer_descriptor_t	bdPool [SAI_XFER_QUEUE_SIZE]
	BD pool for SDMA transfer. More...
sai_transfer_t	saiQueue [SAI_XFER_QUEUE_SIZE]
	Transfer queue storing queued transfer. More...
size_t	transferSize [SAI_XFER_QUEUE_SIZE]
	Data bytes need to transfer.
volatile uint8_t	queueUser
	Index for user to queue transfer. More...
volatile uint8_t	queueDriver
	Index for driver to get the transfer data and size.

Field Documentation

sdma_buffer_descriptor_t sai_sdma_handle_t::bdPool[SAI_XFER_QUEUE_SIZE]

sai_transfer_t sai_sdma_handle_t::saiQueue[SAI_XFER_QUEUE_SIZE]

volatile uint8_t sai_sdma_handle_t::queueUser

Function Documentation

void SAI_TransferTxCreateHandleSDMA	(	I2S_Type *	base,
		sai_sdma_handle_t *	handle,
		sai_sdma_callback_t	callback,
		void *	userData,
		sdma_handle_t *	dmaHandle,
		uint32_t	eventSource
	)

This function initializes the SAI master DMA handle, which can be used for other SAI master transactional APIs. Usually, for a specified SAI instance, call this API once to get the initialized handle.

Parameters

base	SAI base pointer.
handle	SAI SDMA handle pointer.
base	SAI peripheral base address.
callback	Pointer to user callback function.
userData	User parameter passed to the callback function.
dmaHandle	SDMA handle pointer, this handle shall be static allocated by users.

void SAI_TransferRxCreateHandleSDMA	(	I2S_Type *	base,
		sai_sdma_handle_t *	handle,
		sai_sdma_callback_t	callback,
		void *	userData,
		sdma_handle_t *	dmaHandle,
		uint32_t	eventSource
	)

This function initializes the SAI slave DMA handle, which can be used for other SAI master transactional APIs. Usually, for a specified SAI instance, call this API once to get the initialized handle.

Parameters

base	SAI base pointer.
handle	SAI SDMA handle pointer.
base	SAI peripheral base address.
callback	Pointer to user callback function.
userData	User parameter passed to the callback function.
dmaHandle	SDMA handle pointer, this handle shall be static allocated by users.

void SAI_TransferTxSetFormatSDMA	(	I2S_Type *	base,
		sai_sdma_handle_t *	handle,
		sai_transfer_format_t *	format,
		uint32_t	mclkSourceClockHz,
		uint32_t	bclkSourceClockHz
	)

The audio format can be changed at run-time. This function configures the sample rate and audio data format to be transferred. This function also sets the SDMA parameter according to formatting requirements.

Parameters

base	SAI base pointer.
handle	SAI SDMA handle pointer.
format	Pointer to SAI audio data format structure.
mclkSourceClockHz	SAI master clock source frequency in Hz.
bclkSourceClockHz	SAI bit clock source frequency in Hz. If bit clock source is master clock, this value should equals to masterClockHz in format.

Return values

kStatus_Success	Audio format set successfully.
kStatus_InvalidArgument	The input argument is invalid.

void SAI_TransferRxSetFormatSDMA	(	I2S_Type *	base,
		sai_sdma_handle_t *	handle,
		sai_transfer_format_t *	format,
		uint32_t	mclkSourceClockHz,
		uint32_t	bclkSourceClockHz
	)

The audio format can be changed at run-time. This function configures the sample rate and audio data format to be transferred. This function also sets the SDMA parameter according to formatting requirements.

Parameters

base	SAI base pointer.
handle	SAI SDMA handle pointer.
format	Pointer to SAI audio data format structure.
mclkSourceClockHz	SAI master clock source frequency in Hz.
bclkSourceClockHz	SAI bit clock source frequency in Hz. If a bit clock source is the master clock, this value should equal to masterClockHz in format.

Return values

kStatus_Success	Audio format set successfully.
kStatus_InvalidArgument	The input argument is invalid.

status_t SAI_TransferSendSDMA	(	I2S_Type *	base,
		sai_sdma_handle_t *	handle,
		sai_transfer_t *	xfer
	)

Note

This interface returns immediately after the transfer initiates. Call SAI_GetTransferStatus to poll the transfer status and check whether the SAI transfer is finished.

Parameters

base	SAI base pointer.
handle	SAI SDMA handle pointer.
xfer	Pointer to the DMA transfer structure.

Return values

kStatus_Success	Start a SAI SDMA send successfully.
kStatus_InvalidArgument	The input argument is invalid.
kStatus_TxBusy	SAI is busy sending data.

status_t SAI_TransferReceiveSDMA	(	I2S_Type *	base,
		sai_sdma_handle_t *	handle,
		sai_transfer_t *	xfer
	)

Note

This interface returns immediately after the transfer initiates. Call the SAI_GetReceiveRemainingBytes to poll the transfer status and check whether the SAI transfer is finished.

Parameters

base	SAI base pointer
handle	SAI SDMA handle pointer.
xfer	Pointer to DMA transfer structure.

Return values

kStatus_Success	Start a SAI SDMA receive successfully.
kStatus_InvalidArgument	The input argument is invalid.
kStatus_RxBusy	SAI is busy receiving data.

void SAI_TransferAbortSendSDMA	(	I2S_Type *	base,
		sai_sdma_handle_t *	handle
	)

Parameters

base	SAI base pointer.
handle	SAI SDMA handle pointer.

void SAI_TransferAbortReceiveSDMA	(	I2S_Type *	base,
		sai_sdma_handle_t *	handle
	)

Parameters

base	SAI base pointer
handle	SAI SDMA handle pointer.