path: root/lcd4linux_i2c.h

/* $Id: lcd4linux_i2c.h 728 2007-01-14 11:14:38Z michael $
 * $URL: https://ssl.bulix.org/svn/lcd4linux/branches/0.10.1/lcd4linux_i2c.h $
 *
 * user space i2c sturctures and defines, taken from the official kernel i2c 
 * includes to solve the problem when compiling user space application
 * (lcd4linux) with kernel space includes.
 * Should be removed when the kernel team decides on how to solve this
 * user space/kernel space compilation problem in kernel 2.8 or so.
 *
 * Copyright (C) 2005 Paul Kamphuis <pk_richman@users.sourceforge.net>
 * Copyright (C) 2005 The LCD4Linux Team <lcd4linux-devel@users.sourceforge.net>
 *
 * taken from kernel includes i2c.h and i2c-dev.h to prevent using kernel includes
 *   Copyright (C) 1995-2000 Simon G. Vogl
 * With some changes from Ky�sti M�lkki <kmalkki@cc.hut.fi> and
 *  Frodo Looijaard <frodol@dds.nl>
 *
 * This file is part of LCD4Linux.
 *
 * LCD4Linux 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, or (at your option)
 * any later version.
 *
 * LCD4Linux 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.
 *
 */

#ifndef _LCD4LINUX_I2C_H
#define _LCD4LINUX_I2C_H

typedef signed int s32;
typedef signed int __s32;
typedef unsigned char u8;
typedef unsigned short u16;
typedef unsigned char __u8;
typedef unsigned short __u16;
typedef unsigned int u32;
typedef unsigned int __u32;

/* --- General options ------------------------------------------------	*/

struct i2c_msg;
struct i2c_algorithm;
struct i2c_adapter;
struct i2c_client;
struct i2c_driver;
struct i2c_client_address_data;
union i2c_smbus_data;

/*
 * The master routines are the ones normally used to transmit data to devices
 * on a bus (or read from them). Apart from two basic transfer functions to 
 * transmit one message at a time, a more complex version can be used to 
 * transmit an arbitrary number of messages without interruption.
 */
extern int i2c_master_send(struct i2c_client *, const char *, int);
extern int i2c_master_recv(struct i2c_client *, char *, int);

/* Transfer num messages.
 */
extern int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msg, int num);

/*
 * Some adapter types (i.e. PCF 8584 based ones) may support slave behaviuor. 
 * This is not tested/implemented yet and will change in the future.
 */
extern int i2c_slave_send(struct i2c_client *, char *, int);
extern int i2c_slave_recv(struct i2c_client *, char *, int);



/* This is the very generalized SMBus access routine. You probably do not
   want to use this, though; one of the functions below may be much easier,
   and probably just as fast. 
   Note that we use i2c_adapter here, because you do not need a specific
   smbus adapter to call this function. */
extern s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
			  unsigned short flags, char read_write, u8 command, int size, union i2c_smbus_data *data);

/* Now follow the 'nice' access routines. These also document the calling
   conventions of smbus_access. */
/*
extern s32 i2c_smbus_write_quick(struct i2c_client * client, u8 value);
extern s32 i2c_smbus_read_byte(struct i2c_client * client);
extern s32 i2c_smbus_write_byte(struct i2c_client * client, u8 value);
extern s32 i2c_smbus_read_byte_data(struct i2c_client * client, u8 command);
extern s32 i2c_smbus_write_byte_data(struct i2c_client * client,
                                     u8 command, u8 value);
extern s32 i2c_smbus_read_word_data(struct i2c_client * client, u8 command);
extern s32 i2c_smbus_write_word_data(struct i2c_client * client,
                                     u8 command, u16 value);
*/
/* Returns the number of bytes transferred */
/*
extern s32 i2c_smbus_write_block_data(struct i2c_client * client,
				      u8 command, u8 length,
				      u8 *values);
extern s32 i2c_smbus_read_i2c_block_data(struct i2c_client * client,
					 u8 command, u8 *values);
*/

/*
 * A driver is capable of handling one or more physical devices present on
 * I2C adapters. This information is used to inform the driver of adapter
 * events.
 */

/*flags for the driver struct: */
#define I2C_DF_NOTIFY	0x01	/* notify on bus (de/a)ttaches  */

/*flags for the client struct: */
#define I2C_CLIENT_ALLOW_USE		0x01	/* Client allows access */
#define I2C_CLIENT_ALLOW_MULTIPLE_USE 	0x02	/* Allow multiple access-locks */
						/* on an i2c_client */
#define I2C_CLIENT_PEC  0x04	/* Use Packet Error Checking */
#define I2C_CLIENT_TEN	0x10	/* we have a ten bit chip address       */
						/* Must equal I2C_M_TEN below */

/* i2c adapter classes (bitmask) */
#define I2C_CLASS_HWMON		(1<<0)	/* lm_sensors, ... */
#define I2C_CLASS_TV_ANALOG	(1<<1)	/* bttv + friends */
#define I2C_CLASS_TV_DIGITAL	(1<<2)	/* dvb cards */
#define I2C_CLASS_DDC		(1<<3)	/* i2c-matroxfb ? */
#define I2C_CLASS_CAM_ANALOG	(1<<4)	/* camera with analog CCD */
#define I2C_CLASS_CAM_DIGITAL	(1<<5)	/* most webcams */
#define I2C_CLASS_SOUND		(1<<6)	/* sound devices */
#define I2C_CLASS_ALL		(UINT_MAX)	/* all of the above */

/* i2c_client_address_data is the struct for holding default client
 * addresses for a driver and for the parameters supplied on the
 * command line
 */
struct i2c_client_address_data {
    unsigned short *normal_i2c;
    unsigned short *normal_i2c_range;
    unsigned short *probe;
    unsigned short *probe_range;
    unsigned short *ignore;
    unsigned short *ignore_range;
    unsigned short *force;
};

/* Internal numbers to terminate lists */
#define I2C_CLIENT_END		0xfffe
#define I2C_CLIENT_ISA_END	0xfffefffe

/* The numbers to use to set I2C bus address */
#define ANY_I2C_BUS		0xffff
#define ANY_I2C_ISA_BUS		9191

/* The length of the option lists */
#define I2C_CLIENT_MAX_OPTS 48


/* ----- functions exported by i2c.o */

/* administration...
 */
extern int i2c_add_adapter(struct i2c_adapter *);
extern int i2c_del_adapter(struct i2c_adapter *);

extern int i2c_add_driver(struct i2c_driver *);
extern int i2c_del_driver(struct i2c_driver *);

extern int i2c_attach_client(struct i2c_client *);
extern int i2c_detach_client(struct i2c_client *);

/* New function: This is to get an i2c_client-struct for controlling the 
   client either by using i2c_control-function or having the 
   client-module export functions that can be used with the i2c_client
   -struct. */
extern struct i2c_client *i2c_get_client(int driver_id, int adapter_id, struct i2c_client *prev);

/* Should be used with new function
   extern struct i2c_client *i2c_get_client(int,int,struct i2c_client *);
   to make sure that client-struct is valid and that it is okay to access
   the i2c-client. 
   returns -EACCES if client doesn't allow use (default)
   returns -EBUSY if client doesn't allow multiple use (default) and 
   usage_count >0 */
extern int i2c_use_client(struct i2c_client *);
extern int i2c_release_client(struct i2c_client *);

/* call the i2c_client->command() of all attached clients with
 * the given arguments */
extern void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg);

/* returns -EBUSY if address has been taken, 0 if not. Note that the only
   other place at which this is called is within i2c_attach_client; so
   you can cheat by simply not registering. Not recommended, of course! */
extern int i2c_check_addr(struct i2c_adapter *adapter, int addr);

/* Detect function. It iterates over all possible addresses itself.
 * It will only call found_proc if some client is connected at the
 * specific address (unless a 'force' matched);
 */
extern int i2c_probe(struct i2c_adapter *adapter, struct i2c_client_address_data *address_data,
		     int (*found_proc) (struct i2c_adapter *, int, int));

/* An ioctl like call to set div. parameters of the adapter.
 */
extern int i2c_control(struct i2c_client *, unsigned int, unsigned long);

/* This call returns a unique low identifier for each registered adapter,
 * or -1 if the adapter was not registered. 
 */
extern int i2c_adapter_id(struct i2c_adapter *adap);
extern struct i2c_adapter *i2c_get_adapter(int id);
extern void i2c_put_adapter(struct i2c_adapter *adap);


/* Return the functionality mask */
extern u32 i2c_get_functionality(struct i2c_adapter *adap);

/* Return 1 if adapter supports everything we need, 0 if not. */
extern int i2c_check_functionality(struct i2c_adapter *adap, u32 func);

/*
 * I2C Message - used for pure i2c transaction, also from /dev interface
 */
struct i2c_msg {
    __u16 addr;			/* slave address                        */
    __u16 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
    __u16 len;			/* msg length                           */
    __u8 *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_HWPEC_CALC	0x00000008	/* SMBus 2.0 */
#define I2C_FUNC_SMBUS_READ_WORD_DATA_PEC  0x00000800	/* SMBus 2.0 */
#define I2C_FUNC_SMBUS_WRITE_WORD_DATA_PEC 0x00001000	/* SMBus 2.0 */
#define I2C_FUNC_SMBUS_PROC_CALL_PEC	0x00002000	/* SMBus 2.0 */
#define I2C_FUNC_SMBUS_BLOCK_PROC_CALL_PEC 0x00004000	/* SMBus 2.0 */
#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_READ_I2C_BLOCK_2	 0x10000000	/* I2C-like block xfer  */
#define I2C_FUNC_SMBUS_WRITE_I2C_BLOCK_2 0x20000000	/* w/ 2-byte reg. addr. */
#define I2C_FUNC_SMBUS_READ_BLOCK_DATA_PEC  0x40000000	/* SMBus 2.0 */
#define I2C_FUNC_SMBUS_WRITE_BLOCK_DATA_PEC 0x80000000	/* SMBus 2.0 */

#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
#define I2C_FUNC_SMBUS_I2C_BLOCK_2 I2C_FUNC_SMBUS_READ_I2C_BLOCK_2 | \
                                   I2C_FUNC_SMBUS_WRITE_I2C_BLOCK_2
#define I2C_FUNC_SMBUS_BLOCK_DATA_PEC I2C_FUNC_SMBUS_READ_BLOCK_DATA_PEC | \
                                      I2C_FUNC_SMBUS_WRITE_BLOCK_DATA_PEC
#define I2C_FUNC_SMBUS_WORD_DATA_PEC  I2C_FUNC_SMBUS_READ_WORD_DATA_PEC | \
                                      I2C_FUNC_SMBUS_WRITE_WORD_DATA_PEC

#define I2C_FUNC_SMBUS_READ_BYTE_PEC		I2C_FUNC_SMBUS_READ_BYTE_DATA
#define I2C_FUNC_SMBUS_WRITE_BYTE_PEC		I2C_FUNC_SMBUS_WRITE_BYTE_DATA
#define I2C_FUNC_SMBUS_READ_BYTE_DATA_PEC	I2C_FUNC_SMBUS_READ_WORD_DATA
#define I2C_FUNC_SMBUS_WRITE_BYTE_DATA_PEC	I2C_FUNC_SMBUS_WRITE_WORD_DATA
#define I2C_FUNC_SMBUS_BYTE_PEC			I2C_FUNC_SMBUS_BYTE_DATA
#define I2C_FUNC_SMBUS_BYTE_DATA_PEC		I2C_FUNC_SMBUS_WORD_DATA

#define I2C_FUNC_SMBUS_EMUL I2C_FUNC_SMBUS_QUICK | \
                            I2C_FUNC_SMBUS_BYTE | \
                            I2C_FUNC_SMBUS_BYTE_DATA | \
                            I2C_FUNC_SMBUS_WORD_DATA | \
                            I2C_FUNC_SMBUS_PROC_CALL | \
                            I2C_FUNC_SMBUS_WRITE_BLOCK_DATA | \
                            I2C_FUNC_SMBUS_WRITE_BLOCK_DATA_PEC | \
                            I2C_FUNC_SMBUS_I2C_BLOCK

/* 
 * 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 + 3];	/* block[0] is used for length */
    /* one more for read length in block process call */
    /* 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_DATA    6
#define I2C_SMBUS_BLOCK_PROC_CALL   7	/* SMBus 2.0 */
#define I2C_SMBUS_BLOCK_DATA_PEC    8	/* SMBus 2.0 */
#define I2C_SMBUS_PROC_CALL_PEC     9	/* SMBus 2.0 */
#define I2C_SMBUS_BLOCK_PROC_CALL_PEC  10	/* SMBus 2.0 */
#define I2C_SMBUS_WORD_DATA_PEC	   11	/* SMBus 2.0 */


/* ----- 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                   */
#if 0
#define I2C_ACK_TEST	0x0710	/* See if a slave is at a specific address */
#endif

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

/* ... algo-bit.c recognizes */
#define I2C_UDELAY	0x0705	/* set delay in microsecs between each  */
				/* written byte (except address)        */
#define I2C_MDELAY	0x0706	/* millisec delay between written bytes */

/* ----- I2C-DEV: char device interface stuff ------------------------- */

#define I2C_MAJOR	89	/* Device major number          */

/* These defines are used for probing i2c client addresses */
/* Default fill of many variables */
#define I2C_CLIENT_DEFAULTS {I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
                          I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
                          I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
                          I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
                          I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
                          I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
                          I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
                          I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
                          I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
                          I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
                          I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
                          I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
                          I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
                          I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
                          I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
                          I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END}

/* This is ugly. We need to evaluate I2C_CLIENT_MAX_OPTS before it is 
   stringified */
#define I2C_CLIENT_MODPARM_AUX1(x) "1-" #x "h"
#define I2C_CLIENT_MODPARM_AUX(x) I2C_CLIENT_MODPARM_AUX1(x)
#define I2C_CLIENT_MODPARM I2C_CLIENT_MODPARM_AUX(I2C_CLIENT_MAX_OPTS)

/* I2C_CLIENT_MODULE_PARM creates a module parameter, and puts it in the
   module header */

#define I2C_CLIENT_MODULE_PARM(var,desc) \
  static unsigned short var[I2C_CLIENT_MAX_OPTS] = I2C_CLIENT_DEFAULTS; \
  static unsigned int var##_num; \
  /*MODULE_PARM(var,I2C_CLIENT_MODPARM);*/ \
  module_param_array(var, short, &var##_num, 0); \
  MODULE_PARM_DESC(var,desc)

/* This is the one you want to use in your own modules */
#define I2C_CLIENT_INSMOD \
  I2C_CLIENT_MODULE_PARM(probe, \
                      "List of adapter,address pairs to scan additionally"); \
  I2C_CLIENT_MODULE_PARM(probe_range, \
                      "List of adapter,start-addr,end-addr triples to scan " \
                      "additionally"); \
  I2C_CLIENT_MODULE_PARM(ignore, \
                      "List of adapter,address pairs not to scan"); \
  I2C_CLIENT_MODULE_PARM(ignore_range, \
                      "List of adapter,start-addr,end-addr triples not to " \
                      "scan"); \
  I2C_CLIENT_MODULE_PARM(force, \
                      "List of adapter,address pairs to boldly assume " \
                      "to be present"); \
	static struct i2c_client_address_data addr_data = {		\
			.normal_i2c = 		normal_i2c,		\
			.normal_i2c_range =	normal_i2c_range,	\
			.probe =		probe,			\
			.probe_range =		probe_range,		\
			.ignore =		ignore,			\
			.ignore_range =		ignore_range,		\
			.force =		force,			\
		}

/* Detect whether we are on the isa bus. If this returns true, all i2c
   access will fail! */
#define i2c_is_isa_client(clientptr) \
        ((clientptr)->adapter->algo->id == I2C_ALGO_ISA)
#define i2c_is_isa_adapter(adapptr) \
        ((adapptr)->algo->id == I2C_ALGO_ISA)


/* 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 {
    __u8 read_write;
    __u8 command;
    __u32 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 */
    __u32 nmsgs;		/* number of i2c_msgs */
};

#define  I2C_RDRW_IOCTL_MAX_MSGS        42

#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);
}

/* Returns the number of read bytes */
static inline __s32 i2c_smbus_read_i2c_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_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_DATA, &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				/* _LCD4LINUX_I2C_H */