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/*
* This file is part of the coreboot project.
*
* Copyright (C) 2014 Google, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA, 02110-1301 USA
*/
#ifndef _DEVICE_I2C_H_
#define _DEVICE_I2C_H_
#include <stdint.h>
#include <stdlib.h>
struct i2c_seg
{
int read;
uint8_t chip;
uint8_t *buf;
int len;
};
int i2c_transfer(unsigned bus, struct i2c_seg *segments, int count);
/*
* Read a raw chunk of data in one segment and one frame.
*
* [start][slave addr][r][data][stop]
*/
static inline int i2c_read_raw(unsigned bus, uint8_t chip, uint8_t *data,
int len)
{
struct i2c_seg seg =
{ .read = 1, .chip = chip, .buf = data, .len = len };
return i2c_transfer(bus, &seg, 1);
}
/*
* Write a raw chunk of data in one segment and one frame.
*
* [start][slave addr][w][data][stop]
*/
static inline int i2c_write_raw(unsigned bus, uint8_t chip, uint8_t *data,
int len)
{
struct i2c_seg seg =
{ .read = 0, .chip = chip, .buf = data, .len = len };
return i2c_transfer(bus, &seg, 1);
}
/**
* Read a byte with two segments in one frame
*
* [start][slave addr][w][register addr][start][slave addr][r][data][stop]
*/
static inline int i2c_readb(unsigned bus, uint8_t chip, uint8_t reg,
uint8_t *data)
{
struct i2c_seg seg[2];
seg[0].read = 0;
seg[0].chip = chip;
seg[0].buf = ®
seg[0].len = 1;
seg[1].read = 1;
seg[1].chip = chip;
seg[1].buf = data;
seg[1].len = 1;
return i2c_transfer(bus, seg, ARRAY_SIZE(seg));
}
/**
* Write a byte with one segment in one frame.
*
* [start][slave addr][w][register addr][data][stop]
*/
static inline int i2c_writeb(unsigned bus, uint8_t chip, uint8_t reg,
uint8_t data)
{
struct i2c_seg seg;
uint8_t buf[] = {reg, data};
seg.read = 0;
seg.chip = chip;
seg.buf = buf;
seg.len = ARRAY_SIZE(buf);
return i2c_transfer(bus, &seg, 1);
}
#endif /* _DEVICE_I2C_H_ */
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