冷靜: i2c-dev.h

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.
*/

#ifndef _LINUX_I2C_DEV_H
#define _LINUX_I2C_DEV_H

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


/* /dev/i2c-X ioctl commands.  The ioctl's parameter is always an
 * unsigned long, except for:
 * - I2C_FUNCS, takes pointer to an unsigned long
 * - I2C_RDWR, takes pointer to struct i2c_rdwr_ioctl_data
 * - I2C_SMBUS, takes pointer to struct i2c_smbus_ioctl_data
 */
#define I2C_RETRIES 0x0701 /* number of times a device address should
       be polled when not acknowledging */
#define I2C_TIMEOUT 0x0702 /* set timeout in units of 10 ms */

/* NOTE: Slave address is 7 or 10 bits, but 10-bit addresses
 * are NOT supported! (due to code brokenness)
 */
#define I2C_SLAVE 0x0703 /* Use this slave address */
#define I2C_SLAVE_FORCE 0x0706 /* Use this slave address, even if it
       is already in use by a driver! */
#define I2C_TENBIT 0x0704 /* 0 for 7 bit addrs, != 0 for 10 bit */

#define I2C_FUNCS 0x0705 /* Get the adapter functionality mask */

#define I2C_RDWR 0x0707 /* Combined R/W transfer (one STOP only) */

#define I2C_PEC  0x0708 /* != 0 to use PEC with SMBus */
#define I2C_SMBUS 0x0720 /* SMBus transfer */


/* 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


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, const __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,
                                                   const __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 /* _LINUX_I2C_DEV_H */
冷靜

2016年9月20日星期二

i2c-dev.h

沒有留言:

張貼留言

標籤

2016年9月20日 星期二

i2c-dev.h

沒有留言:

張貼留言

2016年9月20日星期二
