Register access functions. More...

Functions
static int	i2cd_register_read (struct i2cd dev, uint16_t addr, uint8_t reg, void buf, size_t len)
	Read bytes from an 8-bit slave register. More...

static int	i2cd_register_read16 (struct i2cd dev, uint16_t addr, uint16_t reg, void buf, size_t len)
	Read bytes from a 16-bit slave register. More...

Detailed Description

Register access functions.

These functions simplify interacting with slave devices that require a repeated START condition to separate writing a register address and reading back content. Register addresses are transmitted in host byte order; if a slave device requires different byte ordering, reg should be converted before being passed as an argument. See endian(3) for more details.

Function Documentation

◆ i2cd_register_read()

static int i2cd_register_read	(	struct i2cd *	dev,
		uint16_t	addr,
		uint8_t	reg,
		void *	buf,
		size_t	len
	)

inlinestatic

Read bytes from an 8-bit slave register.

Parameters

dev	Pointer to an I2C character device handle.
addr	I2C slave address.
reg	I2C slave register.
buf	Pointer to a buffer to receive bytes.
len	Number of bytes to read.

Returns: Number of messages transferred on success, or -1 on error with errno set appropriately.

This function is equivalent to calling:

i2cd_write_read(dev, addr, &reg, sizeof(reg), buf, len);

◆ i2cd_register_read16()

static int i2cd_register_read16	(	struct i2cd *	dev,
		uint16_t	addr,
		uint16_t	reg,
		void *	buf,
		size_t	len
	)