I2C

Functions
void	FlxCard::i2c_read (const char *device_str, u_char reg_addr, u_char *value, int nbytes=1)
void	FlxCard::i2c_write (const char *device_str, u_char reg_addr, u_char data)
void	FlxCard::i2c_write (const char *device_str, u_char reg_addr, u_char *data, int nbytes)
void	FlxCard::i2c_write_byte (u_char dev_addr, u_char byte)
void	FlxCard::i2c_write_byte (u_char dev_addr, u_char reg_addr, u_char byte)
u_char	FlxCard::i2c_read_byte (u_char dev_addr, u_char reg_addr)
bool	FlxCard::i2c_flush (u_int *count=0)
void	FlxCard::i2c_write_bytes (uint8_t dev_addr, uint8_t reg_addr, int nbytes, uint8_t *bytes)
void	FlxCard::i2c_read_bytes (uint8_t dev_addr, uint8_t reg_addr, int nbytes, uint8_t *bytes)

Detailed Description

A set of functions that interact with the onboard I2C bus.

Function Documentation

i2c_read()

void FlxCard::i2c_read	(	const char *	device_str,
		u_char	reg_addr,
		u_char *	value,
		int	nbytes = 1 )

These methods read and write 8-bit data words from/to a named I2C device.

Errors In case of an error, an exception is thrown.

Parameters

*device_str	A string of the form “p1:p2:p3:addr”: see table below for details. Alternatively the string can be the name of the I2C endpoint device You must use the predefined names: find out by running "flx-i2c list"
reg_addr	The address of the register within the device
data	The data that is to be written to the register
value	A pointer to a value that will be filled with the data read from the I2C device

Description of the sub-parameters in parameter device_str:

Sub-parameter	Description
p1	The port number on the primary I2C switch to select; run "flx-i2c list" to find out where the I2C device you want to access, is located in the I2C tree
p2	In case of cascaded switches the secondary switch's port number to select
p3	In case of cascaded switches this is the third switch's port number
addr	The I2C address of the endpoint device behind the switch(es)

As an alternative to a string of the format defined above, parameter device_str can a symbolic name of an I2C endpoint device; get a listing of all available I2C devices on all platforms by running "flx-i2c list all".

i2c_write()

void FlxCard::i2c_write	(	const char *	device_str,
		u_char	reg_addr,
		u_char	data )

See i2c_read() for details

i2c_write_byte() [1/2]

void FlxCard::i2c_write_byte	(	u_char	dev_addr,
		u_char	byte )

These methods read or write one byte of data to/from an I2C address. In case the I2C is stuck the method will abort after 1 second with a time-out error. Before transferring the byte the methods call private function i2c_wait_not_full() in order to make sure that the I2C interface is not busy.

Errors In case of an error, an exception is thrown.

Parameters

dev_addr	The address of the I2C device
byte	The byte that is to be written to the I2C device

i2c_write_byte() [2/2]

void FlxCard::i2c_write_byte	(	u_char	dev_addr,
		u_char	reg_addr,
		u_char	byte )

Parameters

dev_addr	The address of the I2C device
reg_addr	The register address inside the I2C device
byte	The byte that is to be written to the register in the I2C device

i2c_read_byte()

u_char FlxCard::i2c_read_byte	(	u_char	dev_addr,
		u_char	reg_addr )

Parameters

dev_addr	The address of the I2C device
reg_addr	The register address inside the I2C device to read from

i2c_flush()

bool FlxCard::i2c_flush

(

u_int *

count = 0

)

Can be used to flush the I2C read FIFO. Up to 16 bytes are flushed, the exact number returned optionally in 'count'. Errors Returns false if after 16 bytes flushed the FIFO is still not empty.

Parameters

count

Number of bytes flushed

i2c_write_bytes()

void FlxCard::i2c_write_bytes	(	uint8_t	dev_addr,
		uint8_t	reg_addr,
		int	nbytes,
		uint8_t *	bytes )

Read or write one or two bytes of data to/from an I2C address plus register address.