SPI Driver [HAL]

Generic SPI Driver. More...

Collaboration diagram for SPI Driver:

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Description

Generic SPI Driver.

This module implements a generic SPI driver. The driver implements a state machine internally:

The driver is not thread safe for performance reasons, if you need to access the SPI bus from multiple thread then use the spiAcquireBus() and spiReleaseBus() APIs in order to gain exclusive access.

Modules
	SPI Low Level Driver
	SPI Driver low level driver template.
Defines
#define	SPI_USE_MUTUAL_EXCLUSION   TRUE
	Enables the mutual exclusion APIs on the SPI bus.
Enumerations
enum	spistate_t { SPI_UNINIT = 0, SPI_STOP = 1, SPI_READY = 2, SPI_ACTIVE = 3 }
	Driver state machine possible states. More...
Functions
void	spiInit (void)
	SPI Driver initialization.
void	spiObjectInit (SPIDriver *spip)
	Initializes the standard part of a SPIDriver structure.
void	spiStart (SPIDriver *spip, const SPIConfig *config)
	Configures and activates the SPI peripheral.
void	spiStop (SPIDriver *spip)
	Deactivates the SPI peripheral.
void	spiSelect (SPIDriver *spip)
	Asserts the slave select signal and prepares for transfers.
void	spiUnselect (SPIDriver *spip)
	Deasserts the slave select signal.
void	spiIgnore (SPIDriver *spip, size_t n)
	Ignores data on the SPI bus.
void	spiExchange (SPIDriver *spip, size_t n, const void *txbuf, void *rxbuf)
	Exchanges data on the SPI bus.
void	spiSend (SPIDriver *spip, size_t n, const void *txbuf)
	Sends data over the SPI bus.
void	spiReceive (SPIDriver *spip, size_t n, void *rxbuf)
	Receives data from the SPI bus.
void	spiAcquireBus (SPIDriver *spip)
	Gains exclusive access to the SPI bus.
void	spiReleaseBus (SPIDriver *spip)
	Releases exclusive access to the SPI bus.

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Define Documentation

#define SPI_USE_MUTUAL_EXCLUSION   TRUE

Enables the mutual exclusion APIs on the SPI bus.

Definition at line 52 of file spi.h.

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Enumeration Type Documentation

enum spistate_t

Driver state machine possible states.

Enumerator:

SPI_UNINIT	Not initialized.
SPI_STOP	Stopped.
SPI_READY	Ready.
SPI_ACTIVE	Slave selected.

Definition at line 70 of file spi.h.

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Function Documentation

void spiInit

(

void

)

SPI Driver initialization.

Definition at line 59 of file spi.c.

References spi_lld_init().

Referenced by halInit().

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void spiObjectInit

(

SPIDriver *

spip

)

Initializes the standard part of a SPIDriver structure.

Parameters:

[in]

spip

pointer to the SPIDriver object

Definition at line 69 of file spi.c.

References chMtxInit(), chSemInit(), SPIDriver::spd_config, SPIDriver::spd_mutex, and SPIDriver::spd_state.

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void spiStart	(	SPIDriver *	spip,
		const SPIConfig *	config
	)

Configures and activates the SPI peripheral.

Parameters:

[in]	spip	pointer to the SPIDriver object
[in]	config	pointer to the SPIConfig object

Definition at line 88 of file spi.c.

References chDbgAssert, chDbgCheck, chSysLock, chSysUnlock, SPIDriver::spd_config, SPIDriver::spd_state, spi_lld_start(), SPI_READY, and SPI_STOP.

Referenced by mmcConnect(), mmcStartSequentialRead(), and mmcStartSequentialWrite().

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void spiStop

(

SPIDriver *

spip

)

Deactivates the SPI peripheral.

Parameters:

[in]

spip

pointer to the SPIDriver object

Definition at line 107 of file spi.c.

References chDbgAssert, chDbgCheck, chSysLock, chSysUnlock, SPIDriver::spd_state, spi_lld_stop(), SPI_READY, and SPI_STOP.

Referenced by mmcDisconnect(), and mmcStop().

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void spiSelect

(

SPIDriver *

spip

)

Asserts the slave select signal and prepares for transfers.

Parameters:

[in]

spip

pointer to the SPIDriver object

Definition at line 125 of file spi.c.

References chDbgAssert, chDbgCheck, chSysLock, chSysUnlock, SPIDriver::spd_state, SPI_ACTIVE, spi_lld_select(), and SPI_READY.

Referenced by mmcStartSequentialRead(), and mmcStartSequentialWrite().

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void spiUnselect

(

SPIDriver *

spip

)

Deasserts the slave select signal.

The previously selected peripheral is unselected.

Parameters:

[in]

spip

pointer to the SPIDriver object

Definition at line 145 of file spi.c.

References chDbgAssert, chDbgCheck, chSysLock, chSysUnlock, SPIDriver::spd_state, SPI_ACTIVE, spi_lld_unselect(), and SPI_READY.

Referenced by mmcSequentialRead(), mmcSequentialWrite(), mmcStartSequentialRead(), mmcStartSequentialWrite(), mmcStopSequentialRead(), and mmcStopSequentialWrite().

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void spiIgnore	(	SPIDriver *	spip,
		size_t	n
	)

Ignores data on the SPI bus.

This function transmits a series of idle words on the SPI bus and ignores the received data. This function can be invoked even when a slave select signal has not been yet asserted.

Parameters:

[in]	spip	pointer to the SPIDriver object
[in]	n	number of words to be ignored

Definition at line 168 of file spi.c.

References chDbgAssert, chDbgCheck, SPIDriver::spd_state, SPI_ACTIVE, spi_lld_ignore(), and SPI_READY.

Referenced by mmcConnect(), mmcSequentialRead(), and mmcSequentialWrite().

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void spiExchange	(	SPIDriver *	spip,
		size_t	n,
		const void *	txbuf,
		void *	rxbuf
	)

Exchanges data on the SPI bus.

This function performs a simultaneous transmit/receive operation.

Note:

The buffers are organized as uint8_t arrays for data sizes below or equal to 8 bits else it is organized as uint16_t arrays.

Parameters:

[in]	spip	pointer to the SPIDriver object
[in]	n	number of words to be exchanged
[in]	txbuf	the pointer to the transmit buffer
[out]	rxbuf	the pointer to the receive buffer

Definition at line 189 of file spi.c.

References chDbgAssert, chDbgCheck, SPIDriver::spd_state, SPI_ACTIVE, and spi_lld_exchange().

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void spiSend	(	SPIDriver *	spip,
		size_t	n,
		const void *	txbuf
	)

Sends data over the SPI bus.

Note:

The buffers are organized as uint8_t arrays for data sizes below or equal to 8 bits else it is organized as uint16_t arrays.

Parameters:

[in]	spip	pointer to the SPIDriver object
[in]	n	number of words to send
[in]	txbuf	the pointer to the transmit buffer

Definition at line 209 of file spi.c.

References chDbgAssert, chDbgCheck, SPIDriver::spd_state, SPI_ACTIVE, and spi_lld_send().

Referenced by mmcSequentialWrite(), mmcStopSequentialRead(), and mmcStopSequentialWrite().

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void spiReceive	(	SPIDriver *	spip,
		size_t	n,
		void *	rxbuf
	)

Receives data from the SPI bus.

Note:

The buffers are organized as uint8_t arrays for data sizes below or equal to 8 bits else it is organized as uint16_t arrays.

Parameters:

[in]	spip	pointer to the SPIDriver object
[in]	n	number of words to receive
[out]	rxbuf	the pointer to the receive buffer

Definition at line 229 of file spi.c.

References chDbgAssert, chDbgCheck, SPIDriver::spd_state, SPI_ACTIVE, and spi_lld_receive().

Referenced by mmcSequentialRead(), and mmcSequentialWrite().

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void spiAcquireBus

(

SPIDriver *

spip

)

Gains exclusive access to the SPI bus.

This function tries to gain ownership to the SPI bus, if the bus is already being used then the invoking thread is queued.

Note:

This function is only available when the SPI_USE_MUTUAL_EXCLUSION option is set to TRUE.

Parameters:

[in]

spip

pointer to the SPIDriver object

Definition at line 251 of file spi.c.

References chDbgCheck, chMtxLock(), chSemWait(), and SPIDriver::spd_mutex.

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void spiReleaseBus

(

SPIDriver *

spip

)

Releases exclusive access to the SPI bus.

Note:

This function is only available when the SPI_USE_MUTUAL_EXCLUSION option is set to TRUE.

Parameters:

[in]

spip

pointer to the SPIDriver object

Definition at line 269 of file spi.c.

References chDbgCheck, chMtxUnlock(), and chSemSignal().

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