i2c-dev.h

《嵌入式系统设计与实例开发实验教材二源码》Linux内核移植与编译实验

/*
    i2c-dev.h - i2c-bus driver, char device interface

    Copyright (C) 1995-97 Simon G. Vogl
    Copyright (C) 1998-99 Frodo Looijaard <[e-mail]>

    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; either version 2 of the License, or
    (at your option) any later version.

    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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

/* $Id: i2c-dev.h,v 1.2 2004/02/06 13:19:45 laputa Exp $ */

#ifndef I2C_DEV_H
#define I2C_DEV_H


#include <linux/types.h>
#include <linux/i2c.h>

/* Some IOCTL commands are defined in <linux/i2c.h> */
/* Note: 10-bit addresses are NOT supported! */

/* This is the structure as used in the I2C_SMBUS ioctl call */
struct i2c_smbus_ioctl_data {
	char read_write;
	__u8 command;
	int size;
	union i2c_smbus_data *data;
};

/* This is the structure as used in the I2C_RDWR ioctl call */
struct i2c_rdwr_ioctl_data {
	struct i2c_msg *msgs;	/* pointers to i2c_msgs */
	int nmsgs;		/* number of i2c_msgs */
};

/* This is the structure as used in the I2C_SLV_READ ioctl call */
struct i2c_slvR_ioctl_data {
	unsigned short *buffer;		//point to read buffer
	int maxcount;	//max read data length
};

#ifndef __KERNEL__

#include <sys/ioctl.h>

static inline __s32 i2c_smbus_access(int file, char read_write, __u8 command, 
                                     int size, union i2c_smbus_data *data)
{
	struct i2c_smbus_ioctl_data args;

	args.read_write = read_write;
	args.command = command;
	args.size = size;
	args.data = data;
	return ioctl(file,I2C_SMBUS,&args);
}


static inline __s32 i2c_smbus_write_quick(int file, __u8 value)
{
	return i2c_smbus_access(file,value,0,I2C_SMBUS_QUICK,NULL);
}
	
static inline __s32 i2c_smbus_read_byte(int file)
{
	union i2c_smbus_data data;
	if (i2c_smbus_access(file,I2C_SMBUS_READ,0,I2C_SMBUS_BYTE,&data))
		return -1;
	else
		return 0x0FF & data.byte;
}

static inline __s32 i2c_smbus_write_byte(int file, __u8 value)
{
	return i2c_smbus_access(file,I2C_SMBUS_WRITE,value,
	                        I2C_SMBUS_BYTE,NULL);
}

static inline __s32 i2c_smbus_read_byte_data(int file, __u8 command)
{
	union i2c_smbus_data data;
	if (i2c_smbus_access(file,I2C_SMBUS_READ,command,
	                     I2C_SMBUS_BYTE_DATA,&data))
		return -1;
	else
		return 0x0FF & data.byte;
}

static inline __s32 i2c_smbus_write_byte_data(int file, __u8 command, 
                                              __u8 value)
{
	union i2c_smbus_data data;
	data.byte = value;
	return i2c_smbus_access(file,I2C_SMBUS_WRITE,command,
	                        I2C_SMBUS_BYTE_DATA, &data);
}

static inline __s32 i2c_smbus_read_word_data(int file, __u8 command)
{
	union i2c_smbus_data data;
	if (i2c_smbus_access(file,I2C_SMBUS_READ,command,
	                     I2C_SMBUS_WORD_DATA,&data))
		return -1;
	else
		return 0x0FFFF & data.word;
}

static inline __s32 i2c_smbus_write_word_data(int file, __u8 command, 
                                              __u16 value)
{
	union i2c_smbus_data data;
	data.word = value;
	return i2c_smbus_access(file,I2C_SMBUS_WRITE,command,
	                        I2C_SMBUS_WORD_DATA, &data);
}

static inline __s32 i2c_smbus_process_call(int file, __u8 command, __u16 value)
{
	union i2c_smbus_data data;
	data.word = value;
	if (i2c_smbus_access(file,I2C_SMBUS_WRITE,command,
	                     I2C_SMBUS_PROC_CALL,&data))
		return -1;
	else
		return 0x0FFFF & data.word;
}


/* Returns the number of read bytes */
static inline __s32 i2c_smbus_read_block_data(int file, __u8 command, 
                                              __u8 *values)
{
	union i2c_smbus_data data;
	int i;
	if (i2c_smbus_access(file,I2C_SMBUS_READ,command,
	                     I2C_SMBUS_BLOCK_DATA,&data))
		return -1;
	else {
		for (i = 1; i <= data.block[0]; i++)
			values[i-1] = data.block[i];
			return data.block[0];
	}
}

static inline __s32 i2c_smbus_write_block_data(int file, __u8 command, 
                                               __u8 length, __u8 *values)
{
	union i2c_smbus_data data;
	int i;
	if (length > 32)
		length = 32;
	for (i = 1; i <= length; i++)
		data.block[i] = values[i-1];
	data.block[0] = length;
	return i2c_smbus_access(file,I2C_SMBUS_WRITE,command,
	                        I2C_SMBUS_BLOCK_DATA, &data);
}

static inline __s32 i2c_smbus_write_i2c_block_data(int file, __u8 command,
                                               __u8 length, __u8 *values)
{
	union i2c_smbus_data data;
	int i;
	if (length > 32)
		length = 32;
	for (i = 1; i <= length; i++)
		data.block[i] = values[i-1];
	data.block[0] = length;
	return i2c_smbus_access(file,I2C_SMBUS_WRITE,command,
	                        I2C_SMBUS_I2C_BLOCK_DATA, &data);
}

#endif /* ndef __KERNEL__ */

#endif