I2S DMA Driver

Overview

Data Structures
struct	i2s_dma_handle_t
	Members not to be accessed / modified outside of the driver. More...

Typedefs
typedef void(*	i2s_dma_transfer_callback_t )(I2S_Type *base, i2s_dma_handle_t *handle, status_t completionStatus, void *userData)
	Callback function invoked from DMA API on completion. More...

DMA API
void	I2S_TxTransferCreateHandleDMA (I2S_Type *base, i2s_dma_handle_t *handle, dma_handle_t *dmaHandle, i2s_dma_transfer_callback_t callback, void *userData)
	Initializes handle for transfer of audio data. More...
status_t	I2S_TxTransferSendDMA (I2S_Type *base, i2s_dma_handle_t *handle, i2s_transfer_t transfer)
	Begins or queue sending of the given data. More...
void	I2S_TransferAbortDMA (I2S_Type *base, i2s_dma_handle_t *handle)
	Aborts transfer of data. More...
void	I2S_RxTransferCreateHandleDMA (I2S_Type *base, i2s_dma_handle_t *handle, dma_handle_t *dmaHandle, i2s_dma_transfer_callback_t callback, void *userData)
	Initializes handle for reception of audio data. More...
status_t	I2S_RxTransferReceiveDMA (I2S_Type *base, i2s_dma_handle_t *handle, i2s_transfer_t transfer)
	Begins or queue reception of data into given buffer. More...
void	I2S_DMACallback (dma_handle_t *handle, void *userData, bool transferDone, uint32_t tcds)
	Invoked from DMA interrupt handler. More...

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Data Structure Documentation

struct _i2s_dma_handle

Data Fields
uint32_t	state
	Internal state of I2S DMA transfer.
i2s_dma_transfer_callback_t	completionCallback
	Callback function pointer.
void *	userData
	Application data passed to callback.
dma_handle_t *	dmaHandle
	DMA handle.
volatile i2s_transfer_t	i2sQueue [I2S_NUM_BUFFERS]
	Transfer queue storing transfer buffers.
volatile uint8_t	queueUser
	Queue index where user's next transfer will be stored.
volatile uint8_t	queueDriver
	Queue index of buffer actually used by the driver.

Typedef Documentation

typedef void(* i2s_dma_transfer_callback_t)(I2S_Type *base, i2s_dma_handle_t *handle, status_t completionStatus, void *userData)

Parameters

base	I2S base pointer.
handle	pointer to I2S transaction.
completionStatus	status of the transaction.
userData	optional pointer to user arguments data.

Function Documentation

void I2S_TxTransferCreateHandleDMA	(	I2S_Type *	base,
		i2s_dma_handle_t *	handle,
		dma_handle_t *	dmaHandle,
		i2s_dma_transfer_callback_t	callback,
		void *	userData
	)

Parameters

base	I2S base pointer.
handle	pointer to handle structure.
dmaHandle	pointer to dma handle structure.
callback	function to be called back when transfer is done or fails.
userData	pointer to data passed to callback.

status_t I2S_TxTransferSendDMA	(	I2S_Type *	base,
		i2s_dma_handle_t *	handle,
		i2s_transfer_t	transfer
	)

Parameters

base	I2S base pointer.
handle	pointer to handle structure.
transfer	data buffer.

Return values

kStatus_Success
kStatus_I2S_Busy	if all queue slots are occupied with unsent buffers.

void I2S_TransferAbortDMA	(	I2S_Type *	base,
		i2s_dma_handle_t *	handle
	)

Parameters

base	I2S base pointer.
handle	pointer to handle structure.

void I2S_RxTransferCreateHandleDMA	(	I2S_Type *	base,
		i2s_dma_handle_t *	handle,
		dma_handle_t *	dmaHandle,
		i2s_dma_transfer_callback_t	callback,
		void *	userData
	)

Parameters

base	I2S base pointer.
handle	pointer to handle structure.
dmaHandle	pointer to dma handle structure.
callback	function to be called back when transfer is done or fails.
userData	pointer to data passed to callback.

status_t I2S_RxTransferReceiveDMA	(	I2S_Type *	base,
		i2s_dma_handle_t *	handle,
		i2s_transfer_t	transfer
	)

Parameters

base	I2S base pointer.
handle	pointer to handle structure.
transfer	data buffer.

Return values

kStatus_Success
kStatus_I2S_Busy	if all queue slots are occupied with buffers which are not full.

void I2S_DMACallback	(	dma_handle_t *	handle,
		void *	userData,
		bool	transferDone,
		uint32_t	tcds
	)

Parameters

handle	pointer to DMA handle structure.
userData	argument for user callback.
transferDone	if transfer was done.
tcds