spi_master.c File Reference

SPI master common service for SAM.

Copyright (c) 2011-2018 Microchip Technology Inc. and its subsidiaries.

#include "spi_master.h"
#include "flexcom.h"
#include "conf_board.h"

Macros
#define	DEFAULT_CHIP_ID   0
	The default chip select id. More...
#define	MAX_NUM_WITH_DECODER   0x10
	Max number when the chip selects are connected to a 4- to 16-bit decoder. More...
#define	MAX_NUM_WITHOUT_DECODER   0x04
	Max number when the chip selects are directly connected to peripheral device. More...
#define	NONE_CHIP_SELECT_ID   0x0f
	Max number when the chip selects are directly connected to peripheral device. More...

Functions
void	spi_deselect_device (Spi *p_spi, struct spi_device *device)
	Deselect the given device on the SPI bus. More...
void	spi_master_init (Spi *p_spi)
	Initialize the SPI in master mode. More...
void	spi_master_setup_device (Spi *p_spi, struct spi_device *device, spi_flags_t flags, uint32_t baud_rate, board_spi_select_id_t sel_id)
	Set up an SPI device. More...
status_code_t	spi_read_packet (Spi *p_spi, uint8_t *data, size_t len)
	Receive a sequence of bytes from an SPI device. More...
void	spi_select_device (Spi *p_spi, struct spi_device *device)
	Select the given device on the SPI bus. More...
status_code_t	spi_transceive_packet (Spi *p_spi, uint8_t *tx_data, uint8_t *rx_data, size_t len)
	Send and receive a sequence of bytes from an SPI device. More...
status_code_t	spi_write_packet (Spi *p_spi, const uint8_t *data, size_t len)
	Send a sequence of bytes to an SPI device. More...

#define DEFAULT_CHIP_ID   0

The default chip select id.

Referenced by spi_master_init().

#define MAX_NUM_WITH_DECODER   0x10

Max number when the chip selects are connected to a 4- to 16-bit decoder.

Referenced by spi_select_device().

#define MAX_NUM_WITHOUT_DECODER   0x04

Max number when the chip selects are directly connected to peripheral device.

Referenced by spi_select_device().

#define NONE_CHIP_SELECT_ID   0x0f

Max number when the chip selects are directly connected to peripheral device.

Referenced by spi_deselect_device().

void spi_deselect_device	(	Spi *	p_spi,
		struct spi_device *	device
	)

Deselect the given device on the SPI bus.

Call board chip deselect.

Parameters

p_spi	Base address of the SPI instance.
device	SPI device.

Precondition

SPI device must be selected with spi_select_device() first.

References NONE_CHIP_SELECT_ID, spi_is_tx_empty(), spi_set_lastxfer(), spi_set_peripheral_chip_select_value(), and UNUSED.

void spi_master_init

(

Spi *

p_spi

)

Initialize the SPI in master mode.

Parameters

p_spi

Base address of the SPI instance.

References CONFIG_SPI_MASTER_DELAY_BCS, DEFAULT_CHIP_ID, spi_disable_loopback(), spi_disable_mode_fault_detect(), spi_disable_peripheral_select_decode(), spi_enable_clock(), spi_reset(), spi_set_delay_between_chip_select(), spi_set_fixed_peripheral_select(), spi_set_master_mode(), and spi_set_peripheral_chip_select_value().

Referenced by sd_mmc_spi_init().

void spi_master_setup_device	(	Spi *	p_spi,
		struct spi_device *	device,
		spi_flags_t	flags,
		uint32_t	baud_rate,
		board_spi_select_id_t	sel_id
	)

Set up an SPI device.

The returned device descriptor structure must be passed to the driver whenever that device should be used as current slave device.

Parameters

p_spi	Base address of the SPI instance.
device	Pointer to SPI device struct that should be initialized.
flags	SPI configuration flags. Common flags for all implementations are the SPI modes SPI_MODE_0 ... SPI_MODE_3.
baud_rate	Baud rate for communication with slave device in Hz.
sel_id	Board specific select id.

References Assert, CONFIG_SPI_MASTER_BITS_PER_TRANSFER, CONFIG_SPI_MASTER_DELAY_BCT, CONFIG_SPI_MASTER_DELAY_BS, spi_device::id, spi_calc_baudrate_div(), spi_configure_cs_behavior(), SPI_CS_KEEP_LOW, spi_set_baudrate_div(), spi_set_bits_per_transfer(), spi_set_clock_phase(), spi_set_clock_polarity(), spi_set_transfer_delay(), sysclk_get_pba_hz(), and UNUSED.

status_code_t spi_read_packet	(	Spi *	p_spi,
		uint8_t *	data,
		size_t	len
	)

Receive a sequence of bytes from an SPI device.

All bytes sent out on SPI bus are sent as value 0.

Parameters

p_spi	Base address of the SPI instance.
data	Data buffer to read.
len	Length of data to be read.

Precondition

SPI device must be selected with spi_select_device() first.

References CONFIG_SPI_MASTER_DUMMY, ERR_TIMEOUT, spi_is_rx_ready(), spi_is_tx_ready(), spi_read_single(), SPI_TIMEOUT, spi_write_single(), and STATUS_OK.

void spi_select_device	(	Spi *	p_spi,
		struct spi_device *	device
	)

Select the given device on the SPI bus.

Set device specific setting and call board chip select.

Parameters

p_spi	Base address of the SPI instance.
device	SPI device.

References spi_device::id, MAX_NUM_WITH_DECODER, MAX_NUM_WITHOUT_DECODER, spi_get_peripheral_select_decode_setting(), and spi_set_peripheral_chip_select_value().

status_code_t spi_transceive_packet	(	Spi *	p_spi,
		uint8_t *	tx_data,
		uint8_t *	rx_data,
		size_t	len
	)

Send and receive a sequence of bytes from an SPI device.

Parameters

p_spi	Base address of the SPI instance.
tx_data	Data buffer to send.
rx_data	Data buffer to read.
len	Length of data to be read.

Precondition

SPI device must be selected with spi_select_device() first.

References ERR_TIMEOUT, spi_is_rx_ready(), spi_is_tx_ready(), spi_read_single(), SPI_TIMEOUT, spi_write_single(), and STATUS_OK.

status_code_t spi_write_packet	(	Spi *	p_spi,
		const uint8_t *	data,
		size_t	len
	)

Send a sequence of bytes to an SPI device.

Received bytes on the SPI bus are discarded.

Parameters

p_spi	Base address of the SPI instance.
data	Data buffer to write.
len	Length of data to be written.

Precondition

SPI device must be selected with spi_select_device() first.

References ERR_TIMEOUT, spi_is_tx_ready(), SPI_TIMEOUT, spi_write_single(), and STATUS_OK.