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i2c-dev.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 */

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