SAI eDMA Driver

Overview

Files
file	fsl_sai_edma.h

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

Typedefs
typedef void(*	sai_edma_callback_t )(I2S_Type *base, sai_edma_handle_t *handle, status_t status, void *userData)
	SAI eDMA transfer callback function for finish and error.

eDMA Transactional
void	SAI_TransferTxCreateHandleEDMA (I2S_Type *base, sai_edma_handle_t *handle, sai_edma_callback_t callback, void *userData, edma_handle_t *dmaHandle)
	Initializes the SAI eDMA handle. More...
void	SAI_TransferRxCreateHandleEDMA (I2S_Type *base, sai_edma_handle_t *handle, sai_edma_callback_t callback, void *userData, edma_handle_t *dmaHandle)
	Initializes the SAI Rx eDMA handle. More...
void	SAI_TransferTxSetFormatEDMA (I2S_Type *base, sai_edma_handle_t *handle, sai_transfer_format_t *format, uint32_t mclkSourceClockHz, uint32_t bclkSourceClockHz)
	Configures the SAI Tx audio format. More...
void	SAI_TransferRxSetFormatEDMA (I2S_Type *base, sai_edma_handle_t *handle, sai_transfer_format_t *format, uint32_t mclkSourceClockHz, uint32_t bclkSourceClockHz)
	Configures the SAI Rx audio format. More...
status_t	SAI_TransferSendEDMA (I2S_Type *base, sai_edma_handle_t *handle, sai_transfer_t *xfer)
	Performs a non-blocking SAI transfer using DMA. More...
status_t	SAI_TransferReceiveEDMA (I2S_Type *base, sai_edma_handle_t *handle, sai_transfer_t *xfer)
	Performs a non-blocking SAI receive using eDMA. More...
void	SAI_TransferAbortSendEDMA (I2S_Type *base, sai_edma_handle_t *handle)
	Aborts a SAI transfer using eDMA. More...
void	SAI_TransferAbortReceiveEDMA (I2S_Type *base, sai_edma_handle_t *handle)
	Aborts a SAI receive using eDMA. More...
status_t	SAI_TransferGetSendCountEDMA (I2S_Type *base, sai_edma_handle_t *handle, size_t *count)
	Gets byte count sent by SAI. More...
status_t	SAI_TransferGetReceiveCountEDMA (I2S_Type *base, sai_edma_handle_t *handle, size_t *count)
	Gets byte count received by SAI. More...

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Data Structure Documentation

struct _sai_edma_handle

Data Fields
edma_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 eDMA transfer.
sai_edma_callback_t	callback
	Callback for users while transfer finish or error occurs.
void *	userData
	User callback parameter.
edma_tcd_t	tcd [SAI_XFER_QUEUE_SIZE+1U]
	TCD pool for eDMA 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

edma_tcd_t sai_edma_handle_t::tcd[SAI_XFER_QUEUE_SIZE+1U]

sai_transfer_t sai_edma_handle_t::saiQueue[SAI_XFER_QUEUE_SIZE]

volatile uint8_t sai_edma_handle_t::queueUser

Function Documentation

void SAI_TransferTxCreateHandleEDMA	(	I2S_Type *	base,
		sai_edma_handle_t *	handle,
		sai_edma_callback_t	callback,
		void *	userData,
		edma_handle_t *	dmaHandle
	)

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

void SAI_TransferRxCreateHandleEDMA	(	I2S_Type *	base,
		sai_edma_handle_t *	handle,
		sai_edma_callback_t	callback,
		void *	userData,
		edma_handle_t *	dmaHandle
	)

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

void SAI_TransferTxSetFormatEDMA	(	I2S_Type *	base,
		sai_edma_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 eDMA parameter according to formatting requirements.

Parameters

base	SAI base pointer.
handle	SAI eDMA 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_TransferRxSetFormatEDMA	(	I2S_Type *	base,
		sai_edma_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 eDMA parameter according to formatting requirements.

Parameters

base	SAI base pointer.
handle	SAI eDMA 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_TransferSendEDMA	(	I2S_Type *	base,
		sai_edma_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 eDMA handle pointer.
xfer	Pointer to the DMA transfer structure.

Return values

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

status_t SAI_TransferReceiveEDMA	(	I2S_Type *	base,
		sai_edma_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 eDMA handle pointer.
xfer	Pointer to DMA transfer structure.

Return values

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

void SAI_TransferAbortSendEDMA	(	I2S_Type *	base,
		sai_edma_handle_t *	handle
	)

Parameters

base	SAI base pointer.
handle	SAI eDMA handle pointer.

void SAI_TransferAbortReceiveEDMA	(	I2S_Type *	base,
		sai_edma_handle_t *	handle
	)

Parameters

base	SAI base pointer
handle	SAI eDMA handle pointer.

status_t SAI_TransferGetSendCountEDMA	(	I2S_Type *	base,
		sai_edma_handle_t *	handle,
		size_t *	count
	)

Parameters

base	SAI base pointer.
handle	SAI eDMA handle pointer.
count	Bytes count sent by SAI.

Return values

kStatus_Success	Succeed get the transfer count.
kStatus_NoTransferInProgress	There is no non-blocking transaction in progress.

status_t SAI_TransferGetReceiveCountEDMA	(	I2S_Type *	base,
		sai_edma_handle_t *	handle,
		size_t *	count
	)

Parameters

base	SAI base pointer
handle	SAI eDMA handle pointer.
count	Bytes count received by SAI.

Return values

kStatus_Success	Succeed get the transfer count.
kStatus_NoTransferInProgress	There is no non-blocking transaction in progress.