sensor_bus.c File Reference

Sensor API Platform Bus Interfaces.

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

#include <asf.h>
#include "conf_sensors.h"
#include "sensor_bus.h"

Macros
#define	twi_bus_init   bus_init
#define	twi_bus_probe   bus_probe
#define	twi_bus_read   bus_read
#define	twi_bus_write   bus_write

Functions
uint8_t	bus_reg_fieldget (bus_desc_t *bus, uint8_t addr, uint8_t mask)
	Read a field stored at a device register or memory address. More...
void	bus_reg_fieldset (bus_desc_t *bus, uint8_t addr, uint8_t mask, uint8_t value)
	Write a field stored at a device register or memory address. More...
bool	twi_bus_init (volatile void *bus, uint32_t bus_speed)
bool	twi_bus_probe (bus_desc_t *bus, int arg)
size_t	twi_bus_read (bus_desc_t *bus, uint8_t addr, void *data, size_t count)
size_t	twi_bus_write (bus_desc_t *bus, uint8_t addr, const void *data, size_t count)

#define twi_bus_init   bus_init

Sensor API Bus I/O Implementations

#define twi_bus_probe   bus_probe

#define twi_bus_read   bus_read

#define twi_bus_write   bus_write

uint8_t bus_reg_fieldget	(	bus_desc_t *	bus,
		uint8_t	addr,
		uint8_t	mask
	)

Read a field stored at a device register or memory address.

Sensor Platform Board ConfigurationThis routine reads a specified value from a bit field within a 1-Byte device register or memory address. The set bits in the mask parameter determine the field location. For example, if the mask is 30h and the value AFh is stored in the register, the value 2h will be returned.

Parameters

bus	An initialized bus interface descriptor.
addr	The device register or memory address.
mask	The mask of the field to set.

Returns

The value stored in the register or memory field.

References bus_get().

void bus_reg_fieldset	(	bus_desc_t *	bus,
		uint8_t	addr,
		uint8_t	mask,
		uint8_t	value
	)

Write a field stored at a device register or memory address.

This routine writes a specified value to a bit field within a 1-Byte device register or memory address. The set bits in the mask parameter determine the field location. For example, if the mask is 30h and the value is 2h, the value 20h will be bitwise logically OR'd into the 1-Byte register value after clearing the bit values in the field.

Parameters

bus	An initialized bus interface descriptor.
addr	The device register or memory address.
mask	The mask of the field to set.
value	The value of the field to set.

Returns

Nothing

References bus_get(), and bus_put().

bool twi_bus_init	(	volatile void *	bus,
		uint32_t	bus_speed
	)

Initialize the TWI (master) bus I/O interface.

Parameters

bus	The address of an AVR or AVR32 bus interface descriptor.
bus_speed	The bus data rate.

Return values

true	The bus was initialized.
false	The bus was not initialized.

References twi_options_t::speed, STATUS_OK, and twi_master_setup().

bool twi_bus_probe	(	bus_desc_t *	bus,
		int	arg
	)

Determine the existence of a bus device

This routine determines the existence of a device located at a bus interface and address specified by an initialized bus descriptor. Implementations are only required to return true when it can be determined that a device is installed at the bus interface address.

Parameters

bus	An initialized bus interface descriptor.
arg	Ignored reserved argument.

Return values

true	A device responded to the bus address.
false	A device did not respond to the bus address.

References ERR_UNSUPPORTED_DEV, and bus_desc_t::status.

size_t twi_bus_read	(	bus_desc_t *	bus,
		uint8_t	addr,
		void *	data,
		size_t	count
	)

Read bytes from remote device using TWI (master) interface

This routine reads "count" Bytes of data into location "data" from a specified TWI "bus_id" device register or memory address, "addr".

The caller must ensure that "data" specifies a valid memory address that is capable of storing the specified "count" Bytes of data.

Parameters

bus	An initialized bus interface descriptor.
addr	The device register or memory address.
data	The destination read buffer address.
count	The destination read buffer size (Bytes).

Returns

The number of Bytes read, which may be less than the requested number of Bytes in the event of an error.

References bus_desc_t::addr, twi_package_t::chip, bus_desc_t::id, bus_desc_t::no_wait, pkg, bus_desc_t::status, STATUS_OK, and twi_master_read().

size_t twi_bus_write	(	bus_desc_t *	bus,
		uint8_t	addr,
		const void *	data,
		size_t	count
	)

Write bytes to remote device using TWI (master) interface

This routine writes "count" Bytes of data from location "data" to a specified TWI "bus_id" device register or memory address, "addr".

The caller must ensure that "data" specifies a valid memory address.

Parameters

bus	An initialized bus interface descriptor.
addr	The device register or memory address.
data	The source write buffer address.
count	The source write buffer size (Bytes).

Returns

The number of Bytes written, which may be less than the requested number of Bytes in the event of an error.

References bus_desc_t::addr, twi_package_t::chip, bus_desc_t::id, bus_desc_t::no_wait, pkg, bus_desc_t::status, STATUS_OK, and twi_master_write().