SSP DMA Driver

Overview

Typical use case

SSP Operation

Refer to the driver examples codes located at <SDK_ROOT>/boards/<BOARD>/driver_examples/ssp

Data Structures
struct	ssp_dmac_handle_t
	SSP DMAC transfer handle, users should not touch the content of the handle. More...

Typedefs
typedef void(*	ssp_dmac_callback_t )(ssp_dmac_handle_t *handle, status_t transferStatus, void *userData)
	Define SSP DMAC callback.

Driver version
#define	FSL_SSP_DMAC_DRIVER_VERSION   (MAKE_VERSION(2, 0, 0))
	Version 2.0.0.

DMAC Transactional
void	SSP_TransferSendCreateHandleDMAC (SSP_Type *base, ssp_dmac_handle_t *handle, ssp_dmac_callback_t callback, void *userData, dmac_handle_t *dmacHandle)
	Initializes the SSP master DMAC handle. More...
void	SSP_TransferReceiveCreateHandleDMAC (SSP_Type *base, ssp_dmac_handle_t *handle, ssp_dmac_callback_t callback, void *userData, dmac_handle_t *dmacHandle)
	Initializes the SSP receive DMAC handle. More...
status_t	SSP_TransferSendDMAC (ssp_dmac_handle_t *handle, ssp_transfer_t *xfer)
	Performs a non-blocking SSP transfer using DMAC. More...
status_t	SSP_TransferReceiveDMAC (ssp_dmac_handle_t *handle, ssp_transfer_t *xfer)
	Performs a non-blocking SSP transfer using DMAC. More...
void	SSP_TransferAbortSendDMAC (ssp_dmac_handle_t *handle)
	Aborts a SSP transfer using DMAC. More...
void	SSP_TransferAbortReceiveDMAC (ssp_dmac_handle_t *handle)
	Aborts a SSP transfer using DMAC. More...

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Data Structure Documentation

struct _ssp_dmac_handle

A ssp_dmac_handle object can used to represent SSP TX or RX.

Data Fields
SSP_Type *	base
	SSP base address.
dmac_handle_t *	dmacHandle
	DMAC handler for SSP send.
uint32_t	bitWidth
	bit width
dmac_channel_burst_length_t	burstLength
	dmac channel burst length
uint32_t	state
	SSP DMAC transfer internal state.
ssp_dmac_callback_t	callback
	Callback for users while transfer finish or error occurred.
void *	userData
	User callback parameter.

Function Documentation

void SSP_TransferSendCreateHandleDMAC	(	SSP_Type *	base,
		ssp_dmac_handle_t *	handle,
		ssp_dmac_callback_t	callback,
		void *	userData,
		dmac_handle_t *	dmacHandle
	)

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

Parameters

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

void SSP_TransferReceiveCreateHandleDMAC	(	SSP_Type *	base,
		ssp_dmac_handle_t *	handle,
		ssp_dmac_callback_t	callback,
		void *	userData,
		dmac_handle_t *	dmacHandle
	)

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

Parameters

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

status_t SSP_TransferSendDMAC	(	ssp_dmac_handle_t *	handle,
		ssp_transfer_t *	xfer
	)

Note

This interface returns immediately after the transfer initiates.

Parameters

handle	SSP DMAC handle pointer.
xfer	Pointer to DMAC transfer structure.

Return values

kStatus_Success	Successfully start the data receive.
kStatus_SSP_TxBusy	Previous receive still not finished.
kStatus_InvalidArgument	The input parameter is invalid.

status_t SSP_TransferReceiveDMAC	(	ssp_dmac_handle_t *	handle,
		ssp_transfer_t *	xfer
	)

Note

This interface returns immediately after transfer initiates.

Parameters

handle	SSP DMAC handle pointer.
xfer	Pointer to DMAC transfer structure.

Return values

kStatus_Success	Successfully start the data receive.
kStatus_SSP_RxBusy	Previous receive still not finished.
kStatus_InvalidArgument	The input parameter is invalid.

void SSP_TransferAbortSendDMAC

(

ssp_dmac_handle_t *

handle

)

Parameters

handle

SSP DMAC handle pointer.

void SSP_TransferAbortReceiveDMAC

(

ssp_dmac_handle_t *

handle

)

Parameters

handle

SSP DMAC handle pointer.