PDM SDMA Driver

Overview

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

Typedefs
typedef void(*	pdm_sdma_callback_t )(PDM_Type *base, pdm_sdma_handle_t *handle, status_t status, void *userData)
	PDM eDMA transfer callback function for finish and error.

Driver version
#define	FSL_PDM_SDMA_DRIVER_VERSION   (MAKE_VERSION(2, 1, 2))
	Version 2.1.2.

eDMA Transactional
void	PDM_TransferCreateHandleSDMA (PDM_Type *base, pdm_sdma_handle_t *handle, pdm_sdma_callback_t callback, void *userData, sdma_handle_t *dmaHandle, uint32_t eventSource)
	Initializes the PDM eDMA handle. More...
status_t	PDM_TransferReceiveSDMA (PDM_Type *base, pdm_sdma_handle_t *handle, pdm_transfer_t *xfer)
	Performs a non-blocking PDM receive using eDMA. More...
void	PDM_TransferAbortReceiveSDMA (PDM_Type *base, pdm_sdma_handle_t *handle)
	Aborts a PDM receive using eDMA. More...
void	PDM_SetChannelConfigSDMA (PDM_Type *base, pdm_sdma_handle_t *handle, uint32_t channel, const pdm_channel_config_t *config)
	PDM channel configurations. More...

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Data Structure Documentation

struct _pdm_sdma_handle

Data Fields
sdma_handle_t *	dmaHandle
	DMA handler for PDM send.
uint8_t	nbytes
	eDMA minor byte transfer count initially configured. More...
uint8_t	fifoWidth
	fifo width
uint8_t	endChannel
	The last enabled channel.
uint8_t	channelNums
	total channel numbers
uint8_t	count
	The transfer data count in a DMA request.
uint32_t	state
	Internal state for PDM eDMA transfer.
uint32_t	eventSource
	PDM event source number.
pdm_sdma_callback_t	callback
	Callback for users while transfer finish or error occurs.
void *	userData
	User callback parameter.
sdma_buffer_descriptor_t	bdPool [PDM_XFER_QUEUE_SIZE]
	BD pool for SDMA transfer. More...
pdm_transfer_t	pdmQueue [PDM_XFER_QUEUE_SIZE]
	Transfer queue storing queued transfer. More...
size_t	transferSize [PDM_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

uint8_t pdm_sdma_handle_t::nbytes

sdma_buffer_descriptor_t pdm_sdma_handle_t::bdPool[PDM_XFER_QUEUE_SIZE]

pdm_transfer_t pdm_sdma_handle_t::pdmQueue[PDM_XFER_QUEUE_SIZE]

volatile uint8_t pdm_sdma_handle_t::queueUser

Function Documentation

void PDM_TransferCreateHandleSDMA	(	PDM_Type *	base,
		pdm_sdma_handle_t *	handle,
		pdm_sdma_callback_t	callback,
		void *	userData,
		sdma_handle_t *	dmaHandle,
		uint32_t	eventSource
	)

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

Parameters

base	PDM base pointer.
handle	PDM eDMA handle pointer.
base	PDM 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.
dma	request source.

status_t PDM_TransferReceiveSDMA	(	PDM_Type *	base,
		pdm_sdma_handle_t *	handle,
		pdm_transfer_t *	xfer
	)

Note

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

Parameters

base	PDM base pointer
handle	PDM eDMA handle pointer.
xfer	Pointer to DMA transfer structure.

Return values

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

void PDM_TransferAbortReceiveSDMA	(	PDM_Type *	base,
		pdm_sdma_handle_t *	handle
	)

Parameters

base	PDM base pointer
handle	PDM eDMA handle pointer.

void PDM_SetChannelConfigSDMA	(	PDM_Type *	base,
		pdm_sdma_handle_t *	handle,
		uint32_t	channel,
		const pdm_channel_config_t *	config
	)

Parameters

base	PDM base pointer.
handle	PDM eDMA handle pointer.
channel	channel number.
config	channel configurations.