include/dev/i2c.h

/*
 * Copyright (c) 2008 Travis Geiselbrecht
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files
 * (the "Software"), to deal in the Software without restriction,
 * including without limitation the rights to use, copy, modify, merge,
 * publish, distribute, sublicense, and/or sell copies of the Software,
 * and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
#ifndef __DEV_I2C_H
#define __DEV_I2C_H

#include <stdint.h>

#include <stddef.h>     // size_t
#include <sys/types.h>  // status_t

void i2c_init(void);
void i2c_init_early(void);

/* Notes about I2C addresses
 * + Currently, there is no API support for 10-bit I2C addresses.  7-bit only.
 * + Addresses should be supplied as the actual 7-bit address of the device.
 *   The platform driver is responsible for left shifting this address by 1 and
 *   suppling the appropriate value for the R/W bit.
 */

/* send and receive blocks of data */
status_t i2c_transmit(int bus, uint8_t address, const void *buf, size_t count);
status_t i2c_receive(int bus, uint8_t address, void *buf, size_t count);

/* A few convenience routines based on the usual way of accessing registers on
 * i2c slave devices.
 */
status_t i2c_write_reg_bytes(int bus, uint8_t address, uint8_t reg, const uint8_t *val, size_t cnt);
status_t i2c_read_reg_bytes(int bus, uint8_t address, uint8_t reg, uint8_t *val, size_t cnt);

static inline status_t i2c_write_reg(int bus, uint8_t address, uint8_t reg, uint8_t val)
{
    return i2c_write_reg_bytes(bus, address, reg, &val, 1);
}

static inline status_t i2c_read_reg(int bus, uint8_t address, uint8_t reg, uint8_t *val)
{
    return i2c_read_reg_bytes(bus, address, reg, val, 1);
}
#endif