i2c.h File Reference

I2C interface. More...

#include <stdint.h>
#include <ipxe/bitbash.h>

Go to the source code of this file.

Data Structures
struct	i2c_device
	An I2C device. More...
struct	i2c_interface
	An I2C interface. More...
struct	i2c_bit_basher
	A bit-bashing I2C interface. More...

Macros
#define	I2C_TENBIT_ADDRESS   0x7800
	Ten-bit address marker. More...
#define	I2C_WRITE   0
	An I2C write command. More...
#define	I2C_READ   1
	An I2C read command. More...
#define	I2C_UDELAY   5
	Delay required for bit-bashing operation. More...
#define	I2C_RESET_MAX_CYCLES   32
	Maximum number of cycles to use when attempting a bus reset. More...

Enumerations
enum	{ I2C_BIT_SCL = 0, I2C_BIT_SDA }
	Bit indices used for I2C bit-bashing interface. More...

Functions
	FILE_LICENCE (GPL2_OR_LATER_OR_UBDL)
static int	i2c_check_presence (struct i2c_interface *i2c, struct i2c_device *i2cdev)
	Check presence of I2C device. More...
int	init_i2c_bit_basher (struct i2c_bit_basher *i2cbit, struct bit_basher_operations *bash_op)
	Initialise I2C bit-bashing interface. More...
static __always_inline void	init_i2c_eeprom (struct i2c_device *i2cdev, unsigned int dev_addr)
	Initialise generic I2C EEPROM device. More...
static __always_inline void	init_at24c11 (struct i2c_device *i2cdev)
	Initialise Atmel AT24C11. More...

Detailed Description

I2C interface.

Definition in file i2c.h.

Macro Definition Documentation

I2C_TENBIT_ADDRESS

#define I2C_TENBIT_ADDRESS   0x7800

Ten-bit address marker.

This value is ORed with the I2C device address to indicate a ten-bit address format on the bus.

Definition at line 103 of file i2c.h.

I2C_WRITE

#define I2C_WRITE   0

An I2C write command.

Definition at line 106 of file i2c.h.

I2C_READ

#define I2C_READ   1

An I2C read command.

Definition at line 109 of file i2c.h.

I2C_UDELAY

#define I2C_UDELAY   5

Delay required for bit-bashing operation.

Definition at line 120 of file i2c.h.

I2C_RESET_MAX_CYCLES

#define I2C_RESET_MAX_CYCLES   32

Maximum number of cycles to use when attempting a bus reset.

Definition at line 123 of file i2c.h.

Enumeration Type Documentation

anonymous enum

anonymous enum

Bit indices used for I2C bit-bashing interface.

Enumerator
I2C_BIT_SCL	Serial clock.
I2C_BIT_SDA	Serial data.

Definition at line 112 of file i2c.h.

     {
        /** Serial clock */
        I2C_BIT_SCL = 0,
        /** Serial data */
        I2C_BIT_SDA,
};

Function Documentation

FILE_LICENCE()

FILE_LICENCE

(

GPL2_OR_LATER_OR_UBDL

)

i2c_check_presence()

static int i2c_check_presence ( struct i2c_interface *  i2c, struct i2c_device *  i2cdev  )

inlinestatic

Check presence of I2C device.

Parameters

i2c	I2C interface
i2cdev	I2C device

Return values

rc	Return status code

Checks for the presence of the device on the I2C bus by attempting a zero-length write.

Definition at line 135 of file i2c.h.

                                                                   {
        return i2c->write ( i2c, i2cdev, 0, NULL, 0 );
}

References NULL, and i2c_interface::write.

Referenced by exanic_try_init_eeprom(), linda_init_i2c(), and qib7322_init_i2c().

init_i2c_bit_basher()

int init_i2c_bit_basher	(	struct i2c_bit_basher *	i2cbit,
		struct bit_basher_operations *	bash_op
	)

Initialise I2C bit-bashing interface.

Parameters

i2cbit	I2C bit-bashing interface
bash_op	Bit-basher operations

Definition at line 387 of file i2c_bit.c.

                                                                  {
        struct bit_basher *basher = &i2cbit->basher;
        int rc;

        /* Initialise data structures */
        basher->op = bash_op;
        assert ( basher->op->read != NULL );
        assert ( basher->op->write != NULL );
        i2cbit->i2c.read = i2c_bit_read;
        i2cbit->i2c.write = i2c_bit_write;

        /* Reset I2C bus */
        if ( ( rc = i2c_reset ( basher ) ) != 0 ) {
                DBGC ( basher, "I2CBIT %p could not reset I2C bus: %s\n",
                       basher, strerror ( rc ) );
                return rc;
        }

        return 0;
}

References assert(), i2c_bit_basher::basher, DBGC, i2c_bit_basher::i2c, i2c_bit_read(), i2c_bit_write(), i2c_reset(), NULL, bit_basher::op, rc, bit_basher_operations::read, i2c_interface::read, strerror(), bit_basher_operations::write, and i2c_interface::write.

Referenced by exanic_try_init_eeprom(), falcon_probe_spi(), linda_init_i2c(), and qib7322_init_i2c().

init_i2c_eeprom()

static __always_inline void init_i2c_eeprom ( struct i2c_device *  i2cdev, unsigned int  dev_addr  )

inlinestatic

Initialise generic I2C EEPROM device.

Parameters

i2cdev

I2C device

Definition at line 149 of file i2c.h.

                                                                     {
        i2cdev->dev_addr = dev_addr;
        i2cdev->dev_addr_len = 1;
        i2cdev->word_addr_len = 1;
}

References i2c_device::dev_addr, i2c_device::dev_addr_len, and i2c_device::word_addr_len.

Referenced by exanic_try_init_eeprom(), linda_init_i2c(), and qib7322_init_i2c().

init_at24c11()

static __always_inline void init_at24c11 ( struct i2c_device *  i2cdev )

inlinestatic

Initialise Atmel AT24C11.

Parameters

i2cdev

I2C device

Definition at line 161 of file i2c.h.

                                           {
        /* This chip has no device address; it must be the only chip
         * on the bus.  The word address is contained entirely within
         * the device address field.
         */
        i2cdev->dev_addr = 0;
        i2cdev->dev_addr_len = 1;
        i2cdev->word_addr_len = 0;
}

References i2c_device::dev_addr, i2c_device::dev_addr_len, and i2c_device::word_addr_len.