SPI DMA Driver

Overview

This section describes the programming interface of the SPI DMA driver.

Files
file	fsl_spi_dma.h

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

Typedefs
typedef void(*	spi_dma_callback_t )(SPI_Type *base, spi_dma_handle_t *handle, status_t status, void *userData)
	SPI DMA callback called at the end of transfer. More...

Driver version
#define	FSL_SPI_DMA_DRIVER_VERSION   (MAKE_VERSION(2, 0, 4))
	SPI DMA driver version 2.0.4. More...

DMA Transactional
status_t	SPI_MasterTransferCreateHandleDMA (SPI_Type *base, spi_dma_handle_t *handle, spi_dma_callback_t callback, void *userData, dma_handle_t *txHandle, dma_handle_t *rxHandle)
	Initialize the SPI master DMA handle. More...
status_t	SPI_MasterTransferDMA (SPI_Type *base, spi_dma_handle_t *handle, spi_transfer_t *xfer)
	Perform a non-blocking SPI transfer using DMA. More...
status_t	SPI_MasterHalfDuplexTransferDMA (SPI_Type *base, spi_dma_handle_t *handle, spi_half_duplex_transfer_t *xfer)
	Transfers a block of data using a DMA method. More...
static status_t	SPI_SlaveTransferCreateHandleDMA (SPI_Type *base, spi_dma_handle_t *handle, spi_dma_callback_t callback, void *userData, dma_handle_t *txHandle, dma_handle_t *rxHandle)
	Initialize the SPI slave DMA handle. More...
static status_t	SPI_SlaveTransferDMA (SPI_Type *base, spi_dma_handle_t *handle, spi_transfer_t *xfer)
	Perform a non-blocking SPI transfer using DMA. More...
void	SPI_MasterTransferAbortDMA (SPI_Type *base, spi_dma_handle_t *handle)
	Abort a SPI transfer using DMA. More...
status_t	SPI_MasterTransferGetCountDMA (SPI_Type *base, spi_dma_handle_t *handle, size_t *count)
	Gets the master DMA transfer remaining bytes. More...
static void	SPI_SlaveTransferAbortDMA (SPI_Type *base, spi_dma_handle_t *handle)
	Abort a SPI transfer using DMA. More...
static status_t	SPI_SlaveTransferGetCountDMA (SPI_Type *base, spi_dma_handle_t *handle, size_t *count)
	Gets the slave DMA transfer remaining bytes. More...

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Data Structure Documentation

struct _spi_dma_handle

Data Fields
volatile bool	txInProgress
	Send transfer finished.
volatile bool	rxInProgress
	Receive transfer finished.
dma_handle_t *	txHandle
	DMA handler for SPI send.
dma_handle_t *	rxHandle
	DMA handler for SPI receive.
uint8_t	bytesPerFrame
	Bytes in a frame for SPI transfer.
spi_dma_callback_t	callback
	Callback for SPI DMA transfer.
void *	userData
	User Data for SPI DMA callback.
uint32_t	state
	Internal state of SPI DMA transfer.
size_t	transferSize
	Bytes need to be transfer.

Macro Definition Documentation

#define FSL_SPI_DMA_DRIVER_VERSION   (MAKE_VERSION(2, 0, 4))

Typedef Documentation

typedef void(* spi_dma_callback_t)(SPI_Type *base, spi_dma_handle_t *handle, status_t status, void *userData)

Function Documentation

status_t SPI_MasterTransferCreateHandleDMA	(	SPI_Type *	base,
		spi_dma_handle_t *	handle,
		spi_dma_callback_t	callback,
		void *	userData,
		dma_handle_t *	txHandle,
		dma_handle_t *	rxHandle
	)

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

Parameters

base	SPI peripheral base address.
handle	SPI handle pointer.
callback	User callback function called at the end of a transfer.
userData	User data for callback.
txHandle	DMA handle pointer for SPI Tx, the handle shall be static allocated by users.
rxHandle	DMA handle pointer for SPI Rx, the handle shall be static allocated by users.

status_t SPI_MasterTransferDMA	(	SPI_Type *	base,
		spi_dma_handle_t *	handle,
		spi_transfer_t *	xfer
	)

Note

This interface returned immediately after transfer initiates, users should call SPI_GetTransferStatus to poll the transfer status to check whether SPI transfer finished.

Parameters

base	SPI peripheral base address.
handle	SPI DMA handle pointer.
xfer	Pointer to dma transfer structure.

Return values

kStatus_Success	Successfully start a transfer.
kStatus_InvalidArgument	Input argument is invalid.
kStatus_SPI_Busy	SPI is not idle, is running another transfer.

status_t SPI_MasterHalfDuplexTransferDMA	(	SPI_Type *	base,
		spi_dma_handle_t *	handle,
		spi_half_duplex_transfer_t *	xfer
	)

This function using polling way to do the first half transimission and using DMA way to do the srcond half transimission, the transfer mechanism is half-duplex. When do the second half transimission, code will return right away. When all data is transferred, the callback function is called.

Parameters

base	SPI base pointer
handle	A pointer to the spi_master_dma_handle_t structure which stores the transfer state.
transfer	A pointer to the spi_half_duplex_transfer_t structure.

Returns

status of status_t.

static status_t SPI_SlaveTransferCreateHandleDMA ( SPI_Type *  base, spi_dma_handle_t *  handle, spi_dma_callback_t  callback, void *  userData, dma_handle_t *  txHandle, dma_handle_t *  rxHandle  )

inlinestatic

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

Parameters

base	SPI peripheral base address.
handle	SPI handle pointer.
callback	User callback function called at the end of a transfer.
userData	User data for callback.
txHandle	DMA handle pointer for SPI Tx, the handle shall be static allocated by users.
rxHandle	DMA handle pointer for SPI Rx, the handle shall be static allocated by users.

static status_t SPI_SlaveTransferDMA ( SPI_Type *  base, spi_dma_handle_t *  handle, spi_transfer_t *  xfer  )

inlinestatic

Note

This interface returned immediately after transfer initiates, users should call SPI_GetTransferStatus to poll the transfer status to check whether SPI transfer finished.

Parameters

base	SPI peripheral base address.
handle	SPI DMA handle pointer.
xfer	Pointer to dma transfer structure.

Return values

kStatus_Success	Successfully start a transfer.
kStatus_InvalidArgument	Input argument is invalid.
kStatus_SPI_Busy	SPI is not idle, is running another transfer.

void SPI_MasterTransferAbortDMA	(	SPI_Type *	base,
		spi_dma_handle_t *	handle
	)

Parameters

base	SPI peripheral base address.
handle	SPI DMA handle pointer.

status_t SPI_MasterTransferGetCountDMA	(	SPI_Type *	base,
		spi_dma_handle_t *	handle,
		size_t *	count
	)

This function gets the master DMA transfer remaining bytes.

Parameters

base	SPI peripheral base address.
handle	A pointer to the spi_dma_handle_t structure which stores the transfer state.
count	A number of bytes transferred by the non-blocking transaction.

Returns

status of status_t.

static void SPI_SlaveTransferAbortDMA ( SPI_Type *  base, spi_dma_handle_t *  handle  )

inlinestatic

Parameters

base	SPI peripheral base address.
handle	SPI DMA handle pointer.

static status_t SPI_SlaveTransferGetCountDMA ( SPI_Type *  base, spi_dma_handle_t *  handle, size_t *  count  )

inlinestatic

This function gets the slave DMA transfer remaining bytes.

Parameters

base	SPI peripheral base address.
handle	A pointer to the spi_dma_handle_t structure which stores the transfer state.
count	A number of bytes transferred by the non-blocking transaction.

Returns

status of status_t.