I2C

I2C library functions. More...

Functions
int	i2c_init ()
	Initialises the i2c-dev interface for the I2C peripheral exposed on the P1 header (which is dependent on the board revision) More...
int	i2c_init_name (char *devname)
	Initialises the i2c-dev interface for the sysfs entry specified by the devname parameter. More...
int	i2c_select_device (unsigned int fd, unsigned int addr)
	Selects a specific I2C slave device. More...
int	i2c_write (unsigned int fd, unsigned int addr, unsigned char *data, unsigned int len)
	Initiates an I2C write operation. More...
int	i2c_read (unsigned int fd, unsigned int addr, unsigned char *data, unsigned int len)
	Initiates an I2C read operation. More...

Detailed Description

I2C library functions.

Function Documentation

i2c_init()

int i2c_init

(

)

Initialises the i2c-dev interface for the I2C peripheral exposed on the P1 header (which is dependent on the board revision)

Returns

The file descriptor for the relevant i2c-dev interface, -1 for failure

Definition at line 54 of file pi_i2c.c.

i2c_init_name()

int i2c_init_name

(

char *

devname

)

Initialises the i2c-dev interface for the sysfs entry specified by the devname parameter.

Parameters

devname

The sysfs entry for a particular I2C peripheral

Returns

The file descriptor for the relevant i2c-dev interface, -1 for failure

Definition at line 97 of file pi_i2c.c.

i2c_read()

int i2c_read	(	unsigned int	fd,
		unsigned int	addr,
		unsigned char *	data,
		unsigned int	len
	)

Initiates an I2C read operation.

Parameters

fd	File descriptor for the i2c-dev interface
addr	I2C slave device address
data	Pointer to the read buffer
len	Length of data

Returns

1 for success, -1 for failure

Definition at line 176 of file pi_i2c.c.

i2c_select_device()

int i2c_select_device	(	unsigned int	fd,
		unsigned int	addr
	)

Selects a specific I2C slave device.

Parameters

fd	File descriptor for the i2c-dev interface
addr	I2C slave device address

Returns

1 for success, -1 for failure

Definition at line 121 of file pi_i2c.c.

i2c_write()

int i2c_write	(	unsigned int	fd,
		unsigned int	addr,
		unsigned char *	data,
		unsigned int	len
	)

Initiates an I2C write operation.

Parameters

fd	File descriptor for the i2c-dev interface
addr	I2C slave device address
data	Data to write to the device
len	Length of data

Returns

1 for success, -1 for failure

Definition at line 145 of file pi_i2c.c.