SPI Functions

PIOS interface to read and write from SPI ports. More...

Files
file	pios_spi.h
	SPI functions header.
file	pios_spi_priv.h
	SPI private definitions.

Data Structures
struct	pios_spi_dev
struct	pios_spi_cfg

Typedefs
typedef struct pios_spi_dev *	pios_spi_t

Functions
int32_t	PIOS_SPI_Init (pios_spi_t *spi_dev, const struct pios_spi_cfg *cfg)
int32_t	PIOS_SPI_SetClockSpeed (pios_spi_t spi_dev, uint32_t speed)
int32_t	PIOS_SPI_RC_PinSet (pios_spi_t spi_dev, uint32_t slave_id, bool pin_value)
uint8_t	PIOS_SPI_TransferByte (pios_spi_t spi_dev, uint8_t b)
int32_t	PIOS_SPI_TransferBlock (pios_spi_t spi_dev, const uint8_t *send_buffer, uint8_t *receive_buffer, uint16_t len)
int32_t	PIOS_SPI_ClaimBus (pios_spi_t spi_dev)
int32_t	PIOS_SPI_ReleaseBus (pios_spi_t spi_dev)

Detailed Description

PIOS interface to read and write from SPI ports.

Typedef Documentation

typedef struct pios_spi_dev* pios_spi_t

Definition at line 36 of file pios_spi.h.

Function Documentation

int32_t PIOS_SPI_ClaimBus

(

pios_spi_t

spi_dev

)

Claim the SPI bus semaphore.

Parameters

[in]

spi_dev

SPI handle

Returns

0 if no error

-1 if timeout before claiming semaphore

int32_t PIOS_SPI_Init	(	pios_spi_t *	spi_dev,
		const struct pios_spi_cfg *	cfg
	)

Initializes a SPI device.

Parameters

[out]	spi_dev	The handle of the device
[in]	cfg	the SPI configuration

Returns

zero on success, nonzero on failure

int32_t PIOS_SPI_RC_PinSet	(	pios_spi_t	spi_dev,
		uint32_t	slave_id,
		bool	pin_value
	)

Controls the slave select on a SPI port.

Parameters

[in]	spi_dev	the SPI handle
[in]	slave_id	the index of the slave to select/deselect
[in]	pin_value	true to deselect slave, false to select

Returns

0 if no error

int32_t PIOS_SPI_ReleaseBus

(

pios_spi_t

spi_dev

)

Release the SPI bus semaphore.

Parameters

[in]

spi_dev

SPI handle

Returns

0 if no error

int32_t PIOS_SPI_SetClockSpeed	(	pios_spi_t	spi_dev,
		uint32_t	speed
	)

(Re-)initialises SPI peripheral clock rate

Parameters

[in]	spi	SPI number (0 or 1)
[in]	spi_speed	configures the SPI speed in Hz

Returns

The actual attained/configured speed.

int32_t PIOS_SPI_TransferBlock	(	pios_spi_t	spi_dev,
		const uint8_t *	send_buffer,
		uint8_t *	receive_buffer,
		uint16_t	len
	)

Transfers a block of bytes

Parameters

[in]	spi_dev	SPI device handle
[in]	send_buffer	pointer to buffer which should be sent. If NULL, 0xff (all-one) will be sent.
[in]	receive_buffer	pointer to buffer which should get the received values. If NULL, received bytes will be discarded.
[in]	len	number of bytes which should be transfered

Returns

>= 0 if no error during transfer

uint8_t PIOS_SPI_TransferByte	(	pios_spi_t	spi_dev,
		uint8_t	b
	)

Transfers a byte to SPI output and reads back the return value from SPI input

Parameters

[in]	spi_dev	SPI handle
[in]	b	the byte which should be transfered out

Returns

The received byte