I2C DMAC Driver

Overview

The MCUXpresso SDK provides a peripheral driver for the Inter-Integrated Circuit (I2C) DMAC module of MCUXpresso SDK devices.

Data Structures
struct	i2c_master_dmac_handle_t
	I2C master DMAC transfer structure. More...

Macros
#define	I2C_TX_LENGTH   8U
	Retry times for waiting flag. More...

Typedefs
typedef void(*	i2c_master_dmac_transfer_callback_t )(I2C_Type *base, i2c_master_dmac_handle_t *handle, status_t status, void *userData)
	I2C master DMAC transfer callback typedef. More...
typedef void(*	i2c_dmac_master_irq_handler_t )(I2C_Type *base, i2c_master_dmac_handle_t *handle)
	Typedef for master dmac handler. More...

Driver version
#define	FSL_I2C_DMAC_DRIVER_VERSION   (MAKE_VERSION(2, 0, 2))
	I2C DMAC driver version. More...

I2C Master DMAC Transfer Sub-group
void	I2C_MasterTransferCreateHandleDMAC (I2C_Type *base, i2c_master_dmac_handle_t *handle, i2c_master_dmac_transfer_callback_t callback, void *userData, dmac_handle_t *dmacTxHandle, dmac_handle_t *dmacRxHandle)
	Initializes the I2C master transfer in DMAC way. More...
status_t	I2C_MasterTransferDMAC (I2C_Type *base, i2c_master_dmac_handle_t *handle, i2c_master_transfer_t *xfer)
	Initiates a master transfer on the I2C bus in DMAC way. More...
void	I2C_MasterTransferAbortDMAC (I2C_Type *base, i2c_master_dmac_handle_t *handle)
	Aborts an in-process transfer in DMAC way. More...

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Data Structure Documentation

struct _i2c_master_dmac_handle

I2C master DMAC handle typedef.

Data Fields
I2C_Type *	base
	I2C instance base pointer. More...
size_t	transferSize
	Total bytes to be transferred. More...
volatile size_t	dataSize
	Left bytes to be transferred. More...
uint8_t *volatile	data
	Pointer to the user send/receive data buffer. More...
uint16_t	txData [I2C_TX_LENGTH]
	The buffer of re-allocated 16-bit width data to be written to tx register. More...
dmac_channel_transfer_config_t	dmacTxConfig
	The DMAC transfer configuration to transmit data. More...
uint8_t	state
	I2C master transfer status. More...
dmac_handle_t *	dmacTxHandle
	The DMAC handler used for tx. More...
dmac_handle_t *	dmacRxHandle
	The DMAC handler used for rx. More...
i2c_master_dmac_transfer_callback_t	completionCallback
	A callback function called after the DMAC transfer finished. More...
void *	userData
	A callback parameter passed to the callback function. More...

Field Documentation

I2C_Type* i2c_master_dmac_handle_t::base

size_t i2c_master_dmac_handle_t::transferSize

volatile size_t i2c_master_dmac_handle_t::dataSize

uint8_t* volatile i2c_master_dmac_handle_t::data

uint16_t i2c_master_dmac_handle_t::txData[I2C_TX_LENGTH]

dmac_channel_transfer_config_t i2c_master_dmac_handle_t::dmacTxConfig

uint8_t i2c_master_dmac_handle_t::state

dmac_handle_t* i2c_master_dmac_handle_t::dmacTxHandle

dmac_handle_t* i2c_master_dmac_handle_t::dmacRxHandle

i2c_master_dmac_transfer_callback_t i2c_master_dmac_handle_t::completionCallback

void* i2c_master_dmac_handle_t::userData

Macro Definition Documentation

#define FSL_I2C_DMAC_DRIVER_VERSION   (MAKE_VERSION(2, 0, 2))

#define I2C_TX_LENGTH   8U

Buffer length of re-allocated 16-bit width data.

Typedef Documentation

typedef void(* i2c_master_dmac_transfer_callback_t)(I2C_Type *base, i2c_master_dmac_handle_t *handle, status_t status, void *userData)

typedef void(* i2c_dmac_master_irq_handler_t)(I2C_Type *base, i2c_master_dmac_handle_t *handle)

Function Documentation

void I2C_MasterTransferCreateHandleDMAC	(	I2C_Type *	base,
		i2c_master_dmac_handle_t *	handle,
		i2c_master_dmac_transfer_callback_t	callback,
		void *	userData,
		dmac_handle_t *	dmacTxHandle,
		dmac_handle_t *	dmacRxHandle
	)

Parameters

base	I2C peripheral base address
handle	Pointer to i2c_master_dmac_handle_t structure to store the transfer state.
callback	Pointer to the user callback function
userData	User configurable pointer to any data, function, structure etc that user wish to use in the callback
dmacTxHandle	DMAC handle pointer for tx
dmacRxHandle	DMAC handle pointer for rx

status_t I2C_MasterTransferDMAC	(	I2C_Type *	base,
		i2c_master_dmac_handle_t *	handle,
		i2c_master_transfer_t *	xfer
	)

Note

Transfer in DMAC way is non-blocking which means this API returns immediately after transfer initiates. If user installs a user callback when calling I2C_MasterTransferCreateHandleDMAC before, the callback will be invoked when transfer finishes.

Parameters

base	I2C base pointer
handle	pointer to i2c_master_transfer_handle_t structure which stores the transfer state.
xfer	Pointer to the transfer configuration structure.

Return values

kStatus_Success	Successfully start the data transmission.
kStatus_I2C_Busy	Previous transmission still not finished.

void I2C_MasterTransferAbortDMAC	(	I2C_Type *	base,
		i2c_master_dmac_handle_t *	handle
	)

Note

This API can be called at any time after a transfer of DMAC way initiates and before it finishes to abort the transfer early.

Parameters

base	I2C base pointer.
handle	Pointer to i2c_master_handle_t structure which stores the transfer state