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/* Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
/* I2C interface for Chrome EC */
#ifndef __CROS_EC_I2C_H
#define __CROS_EC_I2C_H
#include "common.h"
/* Flags for slave address field, in addition to the 8-bit address */
#define I2C_FLAG_BIG_ENDIAN 0x100 /* 16 byte values are MSB-first */
/* Data structure to define I2C port configuration. */
struct i2c_port_t {
const char *name; /* Port name */
int port; /* Port */
int kbps; /* Speed in kbps */
};
/* Read a 16-bit register from the slave at 8-bit slave address <slaveaddr>, at
* the specified 8-bit <offset> in the slave's address space. */
int i2c_read16(int port, int slave_addr, int offset, int* data);
/* Write a 16-bit register to the slave at 8-bit slave address <slaveaddr>, at
* the specified 8-bit <offset> in the slave's address space. */
int i2c_write16(int port, int slave_addr, int offset, int data);
/* Read an 8-bit register from the slave at 8-bit slave address <slaveaddr>, at
* the specified 8-bit <offset> in the slave's address space. */
int i2c_read8(int port, int slave_addr, int offset, int* data);
/* Write an 8-bit register to the slave at 8-bit slave address <slaveaddr>, at
* the specified 8-bit <offset> in the slave's address space. */
int i2c_write8(int port, int slave_addr, int offset, int data);
/* Read ascii string using smbus read block protocol.
* Read bytestream from <slaveaddr>:<offset> with format:
* [length_N] [byte_0] [byte_1] ... [byte_N-1]
*
* <len> : the max length of receving buffer. to read N bytes
* ascii, len should be at least N+1 to include the
* terminating 0.
* <len> == 0 : buffer size > 255
*/
int i2c_read_string(int port, int slave_addr, int offset, uint8_t *data,
int len);
/**
* Claim an I2C port for use in master mode
*
* If this function succeed, then you must later call board_i2c_release()
* to release the claim.
*
* This function may optionally be implemented by a board file. If provided
* then it should check the port number and arbitrate as needed.
*
* This function will not be called to claim an already-claimed port.
*
* @param port Port to claim (0 for first, 1 for second, etc.)
* @return 0 if claimed successfully, -1 if it is in use
*/
int board_i2c_claim(int port);
/**
* Release an I2C port (after previously being claimed)
*
* This function may optionally be implemented by a board file. If provided
* then it should check the port number and arbitrate as needed.
*
* This function will not be called to release an already-released port.
*
* @param port Port to claim (0 for first, 1 for second, etc.)
*/
void board_i2c_release(int port);
#endif /* __CROS_EC_I2C_H */
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