File Coverage

i2c-dev.h

Criterion	Covered	Total	%
statement	0	78	0.0
branch	0	38	0.0
condition			n/a
subroutine			n/a
pod			n/a
total	0	116	0.0

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

    Copyright (C) 1995-97 Simon G. Vogl
    Copyright (C) 1998-99 Frodo Looijaard

    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
#include


/* -- 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];
        }
}

static inline __s32 i2c_smbus_check_device(int file, int addr) {
    if (ioctl(file, I2C_SLAVE, addr) < 0) {
        return (errno == EBUSY) ? 1 : 0;
    } else {
        int res = i2c_smbus_write_quick(file, I2C_SMBUS_WRITE);
        return (res < 0) ? 0 : 1;
    }
}

#endif /* LIB_I2CDEV_H */