i2c-tools-3.0.2/include/linux/i2c-dev.h - nest-learning-thermostat/5.1.6/i2c-tools - Git at Google

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

     Copyright (C) 1995-97 Simon G. Vogl
     Copyright (C) 1998-99 Frodo Looijaard <frodol@dds.nl>

     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., 51 Franklin Street, Fifth Floor, Boston,
     MA 02110-1301 USA.
 */

 /* $Id: i2c-dev.h 5361 2008-10-19 09:47:02Z khali $ */

 #ifndef LIB_I2CDEV_H
 #define LIB_I2CDEV_H

 #include <linux/types.h>
 #include <sys/ioctl.h>


 /* -- i2c.h -- */


 /*
  * I2C Message - used for pure i2c transaction, also from /dev interface
  */
 struct i2c_msg {
 	__u16 addr;	/* slave address			*/
 	unsigned short flags;
 #define I2C_M_TEN	0x10	/* we have a ten bit chip address	*/
 #define I2C_M_RD	0x01
 #define I2C_M_NOSTART	0x4000
 #define I2C_M_REV_DIR_ADDR	0x2000
 #define I2C_M_IGNORE_NAK	0x1000
 #define I2C_M_NO_RD_ACK		0x0800
 	short len;		/* msg length				*/
 	char *buf;		/* pointer to msg data			*/
 };

 /* To determine what functionality is present */

 #define I2C_FUNC_I2C			0x00000001
 #define I2C_FUNC_10BIT_ADDR		0x00000002
 #define I2C_FUNC_PROTOCOL_MANGLING	0x00000004 /* I2C_M_{REV_DIR_ADDR,NOSTART,..} */
 #define I2C_FUNC_SMBUS_PEC		0x00000008
 #define I2C_FUNC_SMBUS_BLOCK_PROC_CALL	0x00008000 /* SMBus 2.0 */
 #define I2C_FUNC_SMBUS_QUICK		0x00010000
 #define I2C_FUNC_SMBUS_READ_BYTE	0x00020000
 #define I2C_FUNC_SMBUS_WRITE_BYTE	0x00040000
 #define I2C_FUNC_SMBUS_READ_BYTE_DATA	0x00080000
 #define I2C_FUNC_SMBUS_WRITE_BYTE_DATA	0x00100000
 #define I2C_FUNC_SMBUS_READ_WORD_DATA	0x00200000
 #define I2C_FUNC_SMBUS_WRITE_WORD_DATA	0x00400000
 #define I2C_FUNC_SMBUS_PROC_CALL	0x00800000
 #define I2C_FUNC_SMBUS_READ_BLOCK_DATA	0x01000000
 #define I2C_FUNC_SMBUS_WRITE_BLOCK_DATA 0x02000000
 #define I2C_FUNC_SMBUS_READ_I2C_BLOCK	0x04000000 /* I2C-like block xfer  */
 #define I2C_FUNC_SMBUS_WRITE_I2C_BLOCK	0x08000000 /* w/ 1-byte reg. addr. */

 #define I2C_FUNC_SMBUS_BYTE (I2C_FUNC_SMBUS_READ_BYTE | \
                              I2C_FUNC_SMBUS_WRITE_BYTE)
 #define I2C_FUNC_SMBUS_BYTE_DATA (I2C_FUNC_SMBUS_READ_BYTE_DATA | \
                                   I2C_FUNC_SMBUS_WRITE_BYTE_DATA)
 #define I2C_FUNC_SMBUS_WORD_DATA (I2C_FUNC_SMBUS_READ_WORD_DATA | \
                                   I2C_FUNC_SMBUS_WRITE_WORD_DATA)
 #define I2C_FUNC_SMBUS_BLOCK_DATA (I2C_FUNC_SMBUS_READ_BLOCK_DATA | \
                                    I2C_FUNC_SMBUS_WRITE_BLOCK_DATA)
 #define I2C_FUNC_SMBUS_I2C_BLOCK (I2C_FUNC_SMBUS_READ_I2C_BLOCK | \
                                   I2C_FUNC_SMBUS_WRITE_I2C_BLOCK)

 /* Old name, for compatibility */
 #define I2C_FUNC_SMBUS_HWPEC_CALC	I2C_FUNC_SMBUS_PEC

 /*
  * Data for SMBus Messages
  */
 #define I2C_SMBUS_BLOCK_MAX	32	/* As specified in SMBus standard */
 #define I2C_SMBUS_I2C_BLOCK_MAX	32	/* Not specified but we use same structure */
 union i2c_smbus_data {
 	__u8 byte;
 	__u16 word;
 	__u8 block[I2C_SMBUS_BLOCK_MAX + 2]; /* block[0] is used for length */
 	                                            /* and one more for PEC */
 };

 /* smbus_access read or write markers */
 #define I2C_SMBUS_READ	1
 #define I2C_SMBUS_WRITE	0

 /* SMBus transaction types (size parameter in the above functions)
    Note: these no longer correspond to the (arbitrary) PIIX4 internal codes! */
 #define I2C_SMBUS_QUICK		    0
 #define I2C_SMBUS_BYTE		    1
 #define I2C_SMBUS_BYTE_DATA	    2
 #define I2C_SMBUS_WORD_DATA	    3
 #define I2C_SMBUS_PROC_CALL	    4
 #define I2C_SMBUS_BLOCK_DATA	    5
 #define I2C_SMBUS_I2C_BLOCK_BROKEN  6
 #define I2C_SMBUS_BLOCK_PROC_CALL   7		/* SMBus 2.0 */
 #define I2C_SMBUS_I2C_BLOCK_DATA    8


 /* ----- commands for the ioctl like i2c_command call:
  * note that additional calls are defined in the algorithm and hw
  *	dependent layers - these can be listed here, or see the
  *	corresponding header files.
  */
 				/* -> bit-adapter specific ioctls	*/
 #define I2C_RETRIES	0x0701	/* number of times a device address      */
 				/* should be polled when not            */
                                 /* acknowledging 			*/
 #define I2C_TIMEOUT	0x0702	/* set timeout - call with int 		*/


 /* this is for i2c-dev.c	*/
 #define I2C_SLAVE	0x0703	/* Change slave address			*/
 				/* Attn.: Slave address is 7 or 10 bits */
 #define I2C_SLAVE_FORCE	0x0706	/* Change slave address			*/
 				/* Attn.: Slave address is 7 or 10 bits */
 				/* This changes the address, even if it */
 				/* is already taken!			*/
 #define I2C_TENBIT	0x0704	/* 0 for 7 bit addrs, != 0 for 10 bit	*/

 #define I2C_FUNCS	0x0705	/* Get the adapter functionality */
 #define I2C_RDWR	0x0707	/* Combined R/W transfer (one stop only)*/
 #define I2C_PEC		0x0708	/* != 0 for SMBus PEC                   */

 #define I2C_SMBUS	0x0720	/* SMBus-level access */

 /* -- 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 */
 };


 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);
 }

 /* Returns the number of read bytes */
 /* Until kernel 2.6.22, the length is hardcoded to 32 bytes. If you
    ask for less than 32 bytes, your code will only work with kernels
    2.6.23 and later. */
 static inline __s32 i2c_smbus_read_i2c_block_data(int file, __u8 command,
                                                   __u8 length, __u8 *values)
 {
 	union i2c_smbus_data data;
 	int i;

 	if (length > 32)
 		length = 32;
 	data.block[0] = length;
 	if (i2c_smbus_access(file,I2C_SMBUS_READ,command,
 	                     length == 32 ? I2C_SMBUS_I2C_BLOCK_BROKEN :
 	                      I2C_SMBUS_I2C_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_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_BROKEN, &data);
 }

 /* Returns the number of read bytes */
 static inline __s32 i2c_smbus_block_process_call(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;
 	if (i2c_smbus_access(file,I2C_SMBUS_WRITE,command,
 	                     I2C_SMBUS_BLOCK_PROC_CALL,&data))
 		return -1;
 	else {
 		for (i = 1; i <= data.block[0]; i++)
 			values[i-1] = data.block[i];
 		return data.block[0];
 	}
 }


 #endif /* LIB_I2CDEV_H */
	/*
	i2c-dev.h - i2c-bus driver, char device interface

	Copyright (C) 1995-97 Simon G. Vogl
	Copyright (C) 1998-99 Frodo Looijaard <frodol@dds.nl>

	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., 51 Franklin Street, Fifth Floor, Boston,
	MA 02110-1301 USA.
	*/

	/* $Id: i2c-dev.h 5361 2008-10-19 09:47:02Z khali $ */

	#ifndef LIB_I2CDEV_H
	#define LIB_I2CDEV_H

	#include <linux/types.h>
	#include <sys/ioctl.h>


	/* -- i2c.h -- */


	/*
	* I2C Message - used for pure i2c transaction, also from /dev interface
	*/
	struct i2c_msg {
	__u16 addr; /* slave address */
	unsigned short flags;
	#define I2C_M_TEN 0x10 /* we have a ten bit chip address */
	#define I2C_M_RD 0x01
	#define I2C_M_NOSTART 0x4000
	#define I2C_M_REV_DIR_ADDR 0x2000
	#define I2C_M_IGNORE_NAK 0x1000
	#define I2C_M_NO_RD_ACK 0x0800
	short len; /* msg length */
	char buf; / pointer to msg data */
	};

	/* To determine what functionality is present */

	#define I2C_FUNC_I2C 0x00000001
	#define I2C_FUNC_10BIT_ADDR 0x00000002
	#define I2C_FUNC_PROTOCOL_MANGLING 0x00000004 /* I2C_M_{REV_DIR_ADDR,NOSTART,..} */
	#define I2C_FUNC_SMBUS_PEC 0x00000008
	#define I2C_FUNC_SMBUS_BLOCK_PROC_CALL 0x00008000 /* SMBus 2.0 */
	#define I2C_FUNC_SMBUS_QUICK 0x00010000
	#define I2C_FUNC_SMBUS_READ_BYTE 0x00020000
	#define I2C_FUNC_SMBUS_WRITE_BYTE 0x00040000
	#define I2C_FUNC_SMBUS_READ_BYTE_DATA 0x00080000
	#define I2C_FUNC_SMBUS_WRITE_BYTE_DATA 0x00100000
	#define I2C_FUNC_SMBUS_READ_WORD_DATA 0x00200000
	#define I2C_FUNC_SMBUS_WRITE_WORD_DATA 0x00400000
	#define I2C_FUNC_SMBUS_PROC_CALL 0x00800000
	#define I2C_FUNC_SMBUS_READ_BLOCK_DATA 0x01000000
	#define I2C_FUNC_SMBUS_WRITE_BLOCK_DATA 0x02000000
	#define I2C_FUNC_SMBUS_READ_I2C_BLOCK 0x04000000 /* I2C-like block xfer */
	#define I2C_FUNC_SMBUS_WRITE_I2C_BLOCK 0x08000000 /* w/ 1-byte reg. addr. */

	#define I2C_FUNC_SMBUS_BYTE (I2C_FUNC_SMBUS_READ_BYTE \| \
	I2C_FUNC_SMBUS_WRITE_BYTE)
	#define I2C_FUNC_SMBUS_BYTE_DATA (I2C_FUNC_SMBUS_READ_BYTE_DATA \| \
	I2C_FUNC_SMBUS_WRITE_BYTE_DATA)
	#define I2C_FUNC_SMBUS_WORD_DATA (I2C_FUNC_SMBUS_READ_WORD_DATA \| \
	I2C_FUNC_SMBUS_WRITE_WORD_DATA)
	#define I2C_FUNC_SMBUS_BLOCK_DATA (I2C_FUNC_SMBUS_READ_BLOCK_DATA \| \
	I2C_FUNC_SMBUS_WRITE_BLOCK_DATA)
	#define I2C_FUNC_SMBUS_I2C_BLOCK (I2C_FUNC_SMBUS_READ_I2C_BLOCK \| \
	I2C_FUNC_SMBUS_WRITE_I2C_BLOCK)

	/* Old name, for compatibility */
	#define I2C_FUNC_SMBUS_HWPEC_CALC I2C_FUNC_SMBUS_PEC

	/*
	* Data for SMBus Messages
	*/
	#define I2C_SMBUS_BLOCK_MAX 32 /* As specified in SMBus standard */
	#define I2C_SMBUS_I2C_BLOCK_MAX 32 /* Not specified but we use same structure */
	union i2c_smbus_data {
	__u8 byte;
	__u16 word;
	__u8 block[I2C_SMBUS_BLOCK_MAX + 2]; /* block[0] is used for length */
	/* and one more for PEC */
	};

	/* smbus_access read or write markers */
	#define I2C_SMBUS_READ 1
	#define I2C_SMBUS_WRITE 0

	/* SMBus transaction types (size parameter in the above functions)
	Note: these no longer correspond to the (arbitrary) PIIX4 internal codes! */
	#define I2C_SMBUS_QUICK 0
	#define I2C_SMBUS_BYTE 1
	#define I2C_SMBUS_BYTE_DATA 2
	#define I2C_SMBUS_WORD_DATA 3
	#define I2C_SMBUS_PROC_CALL 4
	#define I2C_SMBUS_BLOCK_DATA 5
	#define I2C_SMBUS_I2C_BLOCK_BROKEN 6
	#define I2C_SMBUS_BLOCK_PROC_CALL 7 /* SMBus 2.0 */
	#define I2C_SMBUS_I2C_BLOCK_DATA 8


	/* ----- commands for the ioctl like i2c_command call:
	* note that additional calls are defined in the algorithm and hw
	* dependent layers - these can be listed here, or see the
	* corresponding header files.
	*/
	/* -> bit-adapter specific ioctls */
	#define I2C_RETRIES 0x0701 /* number of times a device address */
	/* should be polled when not */
	/* acknowledging */
	#define I2C_TIMEOUT 0x0702 /* set timeout - call with int */


	/* this is for i2c-dev.c */
	#define I2C_SLAVE 0x0703 /* Change slave address */
	/* Attn.: Slave address is 7 or 10 bits */
	#define I2C_SLAVE_FORCE 0x0706 /* Change slave address */
	/* Attn.: Slave address is 7 or 10 bits */
	/* This changes the address, even if it */
	/* is already taken! */
	#define I2C_TENBIT 0x0704 /* 0 for 7 bit addrs, != 0 for 10 bit */

	#define I2C_FUNCS 0x0705 /* Get the adapter functionality */
	#define I2C_RDWR 0x0707 /* Combined R/W transfer (one stop only)*/
	#define I2C_PEC 0x0708 /* != 0 for SMBus PEC */

	#define I2C_SMBUS 0x0720 /* SMBus-level access */

	/* -- 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 */
	};


	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);
	}

	/* Returns the number of read bytes */
	/* Until kernel 2.6.22, the length is hardcoded to 32 bytes. If you
	ask for less than 32 bytes, your code will only work with kernels
	2.6.23 and later. */
	static inline __s32 i2c_smbus_read_i2c_block_data(int file, __u8 command,
	__u8 length, __u8 *values)
	{
	union i2c_smbus_data data;
	int i;

	if (length > 32)
	length = 32;
	data.block[0] = length;
	if (i2c_smbus_access(file,I2C_SMBUS_READ,command,
	length == 32 ? I2C_SMBUS_I2C_BLOCK_BROKEN :
	I2C_SMBUS_I2C_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_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_BROKEN, &data);
	}

	/* Returns the number of read bytes */
	static inline __s32 i2c_smbus_block_process_call(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;
	if (i2c_smbus_access(file,I2C_SMBUS_WRITE,command,
	I2C_SMBUS_BLOCK_PROC_CALL,&data))
	return -1;
	else {
	for (i = 1; i <= data.block[0]; i++)
	values[i-1] = data.block[i];
	return data.block[0];
	}
	}


	#endif /* LIB_I2CDEV_H */