include/linux/i2c-dev.h

   1 /*
   2     i2c-dev.h - i2c-bus driver, char device interface
   3
   4     Copyright (C) 1995-97 Simon G. Vogl
   5     Copyright (C) 1998-99 Frodo Looijaard <frodol@dds.nl>
   6
   7     This program is free software; you can redistribute it and/or modify
   8     it under the terms of the GNU General Public License as published by
   9     the Free Software Foundation; either version 2 of the License, or
  10     (at your option) any later version.
  11
  12     This program is distributed in the hope that it will be useful,
  13     but WITHOUT ANY WARRANTY; without even the implied warranty of
  14     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15     GNU General Public License for more details.
  16
  17     You should have received a copy of the GNU General Public License
  18     along with this program; if not, write to the Free Software
  19     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20 */
  21
  22 /* $Id: i2c-dev.h,v 1.7 2000/02/15 17:57:27 frodo Exp $ */
  23
  24 #ifndef I2C_DEV_H
  25 #define I2C_DEV_H
  26
  27
  28 #include <linux/types.h>
  29 #include <linux/i2c.h>
  30
  31 /* Some IOCTL commands are defined in <linux/i2c.h> */
  32 /* Note: 10-bit addresses are NOT supported! */
  33
  34 /* This is the structure as used in the I2C_SMBUS ioctl call */
  35 struct i2c_smbus_ioctl_data {
  36         char read_write;
  37         __u8 command;
  38         int size;
  39         union i2c_smbus_data *data;
  40 };
  41
  42 /* This is the structure as used in the I2C_RDWR ioctl call */
  43 struct i2c_rdwr_ioctl_data {
  44         struct i2c_msg *msgs;   /* pointers to i2c_msgs */
  45         int nmsgs;              /* number of i2c_msgs */
  46 };
  47
  48 #ifndef __KERNEL__
  49
  50 #include <sys/ioctl.h>
  51
  52 extern inline __s32 i2c_smbus_access(int file, char read_write, __u8 command,
  53                                      int size, union i2c_smbus_data *data)
  54 {
  55         struct i2c_smbus_ioctl_data args;
  56
  57         args.read_write = read_write;
  58         args.command = command;
  59         args.size = size;
  60         args.data = data;
  61         return ioctl(file,I2C_SMBUS,&args);
  62 }
  63
  64
  65 extern inline __s32 i2c_smbus_write_quick(int file, __u8 value)
  66 {
  67         return i2c_smbus_access(file,value,0,I2C_SMBUS_QUICK,NULL);
  68 }
  69
  70 extern inline __s32 i2c_smbus_read_byte(int file)
  71 {
  72         union i2c_smbus_data data;
  73         if (i2c_smbus_access(file,I2C_SMBUS_READ,0,I2C_SMBUS_BYTE,&data))
  74                 return -1;
  75         else
  76                 return 0x0FF & data.byte;
  77 }
  78
  79 extern inline __s32 i2c_smbus_write_byte(int file, __u8 value)
  80 {
  81         return i2c_smbus_access(file,I2C_SMBUS_WRITE,value,
  82                                 I2C_SMBUS_BYTE,NULL);
  83 }
  84
  85 extern inline __s32 i2c_smbus_read_byte_data(int file, __u8 command)
  86 {
  87         union i2c_smbus_data data;
  88         if (i2c_smbus_access(file,I2C_SMBUS_READ,command,
  89                              I2C_SMBUS_BYTE_DATA,&data))
  90                 return -1;
  91         else
  92                 return 0x0FF & data.byte;
  93 }
  94
  95 extern inline __s32 i2c_smbus_write_byte_data(int file, __u8 command,
  96                                               __u8 value)
  97 {
  98         union i2c_smbus_data data;
  99         data.byte = value;
 100         return i2c_smbus_access(file,I2C_SMBUS_WRITE,command,
 101                                 I2C_SMBUS_BYTE_DATA, &data);
 102 }
 103
 104 extern inline __s32 i2c_smbus_read_word_data(int file, __u8 command)
 105 {
 106         union i2c_smbus_data data;
 107         if (i2c_smbus_access(file,I2C_SMBUS_READ,command,
 108                              I2C_SMBUS_WORD_DATA,&data))
 109                 return -1;
 110         else
 111                 return 0x0FFFF & data.word;
 112 }
 113
 114 extern inline __s32 i2c_smbus_write_word_data(int file, __u8 command,
 115                                               __u16 value)
 116 {
 117         union i2c_smbus_data data;
 118         data.word = value;
 119         return i2c_smbus_access(file,I2C_SMBUS_WRITE,command,
 120                                 I2C_SMBUS_WORD_DATA, &data);
 121 }
 122
 123 extern inline __s32 i2c_smbus_process_call(int file, __u8 command, __u16 value)
 124 {
 125         union i2c_smbus_data data;
 126         data.word = value;
 127         if (i2c_smbus_access(file,I2C_SMBUS_WRITE,command,
 128                              I2C_SMBUS_PROC_CALL,&data))
 129                 return -1;
 130         else
 131                 return 0x0FFFF & data.word;
 132 }
 133
 134
 135 /* Returns the number of read bytes */
 136 extern inline __s32 i2c_smbus_read_block_data(int file, __u8 command,
 137                                               __u8 *values)
 138 {
 139         union i2c_smbus_data data;
 140         int i;
 141         if (i2c_smbus_access(file,I2C_SMBUS_READ,command,
 142                              I2C_SMBUS_BLOCK_DATA,&data))
 143                 return -1;
 144         else {
 145                 for (i = 1; i <= data.block[0]; i++)
 146                         values[i-1] = data.block[i];
 147                         return data.block[0];
 148         }
 149 }
 150
 151 extern inline __s32 i2c_smbus_write_block_data(int file, __u8 command,
 152                                                __u8 length, __u8 *values)
 153 {
 154         union i2c_smbus_data data;
 155         int i;
 156         if (length > 32)
 157                 length = 32;
 158         for (i = 1; i <= length; i++)
 159                 data.block[i] = values[i-1];
 160         data.block[0] = length;
 161         return i2c_smbus_access(file,I2C_SMBUS_WRITE,command,
 162                                 I2C_SMBUS_BLOCK_DATA, &data);
 163 }
 164
 165 #endif /* ndef __KERNEL__ */
 166
 167 #endif