release/src-rt-6.x.4708/toolchains/hndtools-arm-linux-2.6.36-uclibc-4.5.3/arm-brcm-linux-uclibcgnueabi/sysroot/usr/include/linux/i2c.h

   1 /* ------------------------------------------------------------------------- */
   2 /*                                                                           */
   3 /* i2c.h - definitions for the i2c-bus interface                             */
   4 /*                                                                           */
   5 /* ------------------------------------------------------------------------- */
   6 /*   Copyright (C) 1995-2000 Simon G. Vogl
   7
   8     This program is free software; you can redistribute it and/or modify
   9     it under the terms of the GNU General Public License as published by
  10     the Free Software Foundation; either version 2 of the License, or
  11     (at your option) any later version.
  12
  13     This program is distributed in the hope that it will be useful,
  14     but WITHOUT ANY WARRANTY; without even the implied warranty of
  15     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16     GNU General Public License for more details.
  17
  18     You should have received a copy of the GNU General Public License
  19     along with this program; if not, write to the Free Software
  20     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.                */
  21 /* ------------------------------------------------------------------------- */
  22
  23 /* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and
  24    Frodo Looijaard <frodol@dds.nl> */
  25
  26 #ifndef _LINUX_I2C_H
  27 #define _LINUX_I2C_H
  28
  29 #include <linux/types.h>
  30
  31 /**
  32  * struct i2c_msg - an I2C transaction segment beginning with START
  33  * @addr: Slave address, either seven or ten bits.  When this is a ten
  34  *      bit address, I2C_M_TEN must be set in @flags and the adapter
  35  *      must support I2C_FUNC_10BIT_ADDR.
  36  * @flags: I2C_M_RD is handled by all adapters.  No other flags may be
  37  *      provided unless the adapter exported the relevant I2C_FUNC_*
  38  *      flags through i2c_check_functionality().
  39  * @len: Number of data bytes in @buf being read from or written to the
  40  *      I2C slave address.  For read transactions where I2C_M_RECV_LEN
  41  *      is set, the caller guarantees that this buffer can hold up to
  42  *      32 bytes in addition to the initial length byte sent by the
  43  *      slave (plus, if used, the SMBus PEC); and this value will be
  44  *      incremented by the number of block data bytes received.
  45  * @buf: The buffer into which data is read, or from which it's written.
  46  *
  47  * An i2c_msg is the low level representation of one segment of an I2C
  48  * transaction.  It is visible to drivers in the @i2c_transfer() procedure,
  49  * to userspace from i2c-dev, and to I2C adapter drivers through the
  50  * @i2c_adapter.@master_xfer() method.
  51  *
  52  * Except when I2C "protocol mangling" is used, all I2C adapters implement
  53  * the standard rules for I2C transactions.  Each transaction begins with a
  54  * START.  That is followed by the slave address, and a bit encoding read
  55  * versus write.  Then follow all the data bytes, possibly including a byte
  56  * with SMBus PEC.  The transfer terminates with a NAK, or when all those
  57  * bytes have been transferred and ACKed.  If this is the last message in a
  58  * group, it is followed by a STOP.  Otherwise it is followed by the next
  59  * @i2c_msg transaction segment, beginning with a (repeated) START.
  60  *
  61  * Alternatively, when the adapter supports I2C_FUNC_PROTOCOL_MANGLING then
  62  * passing certain @flags may have changed those standard protocol behaviors.
  63  * Those flags are only for use with broken/nonconforming slaves, and with
  64  * adapters which are known to support the specific mangling options they
  65  * need (one or more of IGNORE_NAK, NO_RD_ACK, NOSTART, and REV_DIR_ADDR).
  66  */
  67 struct i2c_msg {
  68         __u16 addr;     /* slave address                        */
  69         __u16 flags;
  70 #define I2C_M_TEN               0x0010  /* this is a ten bit chip address */
  71 #define I2C_M_RD                0x0001  /* read data, from slave to master */
  72 #define I2C_M_NOSTART           0x4000  /* if I2C_FUNC_PROTOCOL_MANGLING */
  73 #define I2C_M_REV_DIR_ADDR      0x2000  /* if I2C_FUNC_PROTOCOL_MANGLING */
  74 #define I2C_M_IGNORE_NAK        0x1000  /* if I2C_FUNC_PROTOCOL_MANGLING */
  75 #define I2C_M_NO_RD_ACK         0x0800  /* if I2C_FUNC_PROTOCOL_MANGLING */
  76 #define I2C_M_RECV_LEN          0x0400  /* length will be first received byte */
  77         __u16 len;              /* msg length                           */
  78         __u8 *buf;              /* pointer to msg data                  */
  79 };
  80
  81 /* To determine what functionality is present */
  82
  83 #define I2C_FUNC_I2C                    0x00000001
  84 #define I2C_FUNC_10BIT_ADDR             0x00000002
  85 #define I2C_FUNC_PROTOCOL_MANGLING      0x00000004 /* I2C_M_NOSTART etc. */
  86 #define I2C_FUNC_SMBUS_PEC              0x00000008
  87 #define I2C_FUNC_SMBUS_BLOCK_PROC_CALL  0x00008000 /* SMBus 2.0 */
  88 #define I2C_FUNC_SMBUS_QUICK            0x00010000
  89 #define I2C_FUNC_SMBUS_READ_BYTE        0x00020000
  90 #define I2C_FUNC_SMBUS_WRITE_BYTE       0x00040000
  91 #define I2C_FUNC_SMBUS_READ_BYTE_DATA   0x00080000
  92 #define I2C_FUNC_SMBUS_WRITE_BYTE_DATA  0x00100000
  93 #define I2C_FUNC_SMBUS_READ_WORD_DATA   0x00200000
  94 #define I2C_FUNC_SMBUS_WRITE_WORD_DATA  0x00400000
  95 #define I2C_FUNC_SMBUS_PROC_CALL        0x00800000
  96 #define I2C_FUNC_SMBUS_READ_BLOCK_DATA  0x01000000
  97 #define I2C_FUNC_SMBUS_WRITE_BLOCK_DATA 0x02000000
  98 #define I2C_FUNC_SMBUS_READ_I2C_BLOCK   0x04000000 /* I2C-like block xfer  */
  99 #define I2C_FUNC_SMBUS_WRITE_I2C_BLOCK  0x08000000 /* w/ 1-byte reg. addr. */
 100
 101 #define I2C_FUNC_SMBUS_BYTE             (I2C_FUNC_SMBUS_READ_BYTE | \
 102                                          I2C_FUNC_SMBUS_WRITE_BYTE)
 103 #define I2C_FUNC_SMBUS_BYTE_DATA        (I2C_FUNC_SMBUS_READ_BYTE_DATA | \
 104                                          I2C_FUNC_SMBUS_WRITE_BYTE_DATA)
 105 #define I2C_FUNC_SMBUS_WORD_DATA        (I2C_FUNC_SMBUS_READ_WORD_DATA | \
 106                                          I2C_FUNC_SMBUS_WRITE_WORD_DATA)
 107 #define I2C_FUNC_SMBUS_BLOCK_DATA       (I2C_FUNC_SMBUS_READ_BLOCK_DATA | \
 108                                          I2C_FUNC_SMBUS_WRITE_BLOCK_DATA)
 109 #define I2C_FUNC_SMBUS_I2C_BLOCK        (I2C_FUNC_SMBUS_READ_I2C_BLOCK | \
 110                                          I2C_FUNC_SMBUS_WRITE_I2C_BLOCK)
 111
 112 #define I2C_FUNC_SMBUS_EMUL             (I2C_FUNC_SMBUS_QUICK | \
 113                                          I2C_FUNC_SMBUS_BYTE | \
 114                                          I2C_FUNC_SMBUS_BYTE_DATA | \
 115                                          I2C_FUNC_SMBUS_WORD_DATA | \
 116                                          I2C_FUNC_SMBUS_PROC_CALL | \
 117                                          I2C_FUNC_SMBUS_WRITE_BLOCK_DATA | \
 118                                          I2C_FUNC_SMBUS_I2C_BLOCK | \
 119                                          I2C_FUNC_SMBUS_PEC)
 120
 121 /*
 122  * Data for SMBus Messages
 123  */
 124 #define I2C_SMBUS_BLOCK_MAX     32      /* As specified in SMBus standard */
 125 union i2c_smbus_data {
 126         __u8 byte;
 127         __u16 word;
 128         __u8 block[I2C_SMBUS_BLOCK_MAX + 2]; /* block[0] is used for length */
 129                                /* and one more for user-space compatibility */
 130 };
 131
 132 /* i2c_smbus_xfer read or write markers */
 133 #define I2C_SMBUS_READ  1
 134 #define I2C_SMBUS_WRITE 0
 135
 136 /* SMBus transaction types (size parameter in the above functions)
 137    Note: these no longer correspond to the (arbitrary) PIIX4 internal codes! */
 138 #define I2C_SMBUS_QUICK             0
 139 #define I2C_SMBUS_BYTE              1
 140 #define I2C_SMBUS_BYTE_DATA         2
 141 #define I2C_SMBUS_WORD_DATA         3
 142 #define I2C_SMBUS_PROC_CALL         4
 143 #define I2C_SMBUS_BLOCK_DATA        5
 144 #define I2C_SMBUS_I2C_BLOCK_BROKEN  6
 145 #define I2C_SMBUS_BLOCK_PROC_CALL   7           /* SMBus 2.0 */
 146 #define I2C_SMBUS_I2C_BLOCK_DATA    8
 147
 148 #endif /* _LINUX_I2C_H */