159 lines
7.0 KiB
C
159 lines
7.0 KiB
C
/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
|
|
/* ------------------------------------------------------------------------- */
|
|
/* */
|
|
/* i2c.h - definitions for the i2c-bus interface */
|
|
/* */
|
|
/* ------------------------------------------------------------------------- */
|
|
/* Copyright (C) 1995-2000 Simon G. Vogl
|
|
|
|
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. */
|
|
/* ------------------------------------------------------------------------- */
|
|
|
|
/* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and
|
|
Frodo Looijaard <frodol@dds.nl> */
|
|
|
|
#ifndef _LINUX_I2C_H
|
|
#define _LINUX_I2C_H
|
|
|
|
#include <linux/types.h>
|
|
|
|
/**
|
|
* struct i2c_msg - an I2C transaction segment beginning with START
|
|
* @addr: Slave address, either seven or ten bits. When this is a ten
|
|
* bit address, I2C_M_TEN must be set in @flags and the adapter
|
|
* must support I2C_FUNC_10BIT_ADDR.
|
|
* @flags: I2C_M_RD is handled by all adapters. No other flags may be
|
|
* provided unless the adapter exported the relevant I2C_FUNC_*
|
|
* flags through i2c_check_functionality().
|
|
* @len: Number of data bytes in @buf being read from or written to the
|
|
* I2C slave address. For read transactions where I2C_M_RECV_LEN
|
|
* is set, the caller guarantees that this buffer can hold up to
|
|
* 32 bytes in addition to the initial length byte sent by the
|
|
* slave (plus, if used, the SMBus PEC); and this value will be
|
|
* incremented by the number of block data bytes received.
|
|
* @buf: The buffer into which data is read, or from which it's written.
|
|
*
|
|
* An i2c_msg is the low level representation of one segment of an I2C
|
|
* transaction. It is visible to drivers in the @i2c_transfer() procedure,
|
|
* to userspace from i2c-dev, and to I2C adapter drivers through the
|
|
* @i2c_adapter.@master_xfer() method.
|
|
*
|
|
* Except when I2C "protocol mangling" is used, all I2C adapters implement
|
|
* the standard rules for I2C transactions. Each transaction begins with a
|
|
* START. That is followed by the slave address, and a bit encoding read
|
|
* versus write. Then follow all the data bytes, possibly including a byte
|
|
* with SMBus PEC. The transfer terminates with a NAK, or when all those
|
|
* bytes have been transferred and ACKed. If this is the last message in a
|
|
* group, it is followed by a STOP. Otherwise it is followed by the next
|
|
* @i2c_msg transaction segment, beginning with a (repeated) START.
|
|
*
|
|
* Alternatively, when the adapter supports I2C_FUNC_PROTOCOL_MANGLING then
|
|
* passing certain @flags may have changed those standard protocol behaviors.
|
|
* Those flags are only for use with broken/nonconforming slaves, and with
|
|
* adapters which are known to support the specific mangling options they
|
|
* need (one or more of IGNORE_NAK, NO_RD_ACK, NOSTART, and REV_DIR_ADDR).
|
|
*/
|
|
struct i2c_msg {
|
|
__u16 addr; /* slave address */
|
|
__u16 flags;
|
|
#define I2C_M_RD 0x0001 /* read data, from slave to master */
|
|
/* I2C_M_RD is guaranteed to be 0x0001! */
|
|
#define I2C_M_TEN 0x0010 /* this is a ten bit chip address */
|
|
#define I2C_M_DMA_SAFE 0x0200 /* the buffer of this message is DMA safe */
|
|
/* makes only sense in kernelspace */
|
|
/* userspace buffers are copied anyway */
|
|
#define I2C_M_RECV_LEN 0x0400 /* length will be first received byte */
|
|
#define I2C_M_NO_RD_ACK 0x0800 /* if I2C_FUNC_PROTOCOL_MANGLING */
|
|
#define I2C_M_IGNORE_NAK 0x1000 /* if I2C_FUNC_PROTOCOL_MANGLING */
|
|
#define I2C_M_REV_DIR_ADDR 0x2000 /* if I2C_FUNC_PROTOCOL_MANGLING */
|
|
#define I2C_M_NOSTART 0x4000 /* if I2C_FUNC_NOSTART */
|
|
#define I2C_M_STOP 0x8000 /* if I2C_FUNC_PROTOCOL_MANGLING */
|
|
__u16 len; /* msg length */
|
|
__u8 *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_IGNORE_NAK etc. */
|
|
#define I2C_FUNC_SMBUS_PEC 0x00000008
|
|
#define I2C_FUNC_NOSTART 0x00000010 /* I2C_M_NOSTART */
|
|
#define I2C_FUNC_SLAVE 0x00000020
|
|
#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_HOST_NOTIFY 0x10000000
|
|
|
|
#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)
|
|
|
|
#define I2C_FUNC_SMBUS_EMUL (I2C_FUNC_SMBUS_QUICK | \
|
|
I2C_FUNC_SMBUS_BYTE | \
|
|
I2C_FUNC_SMBUS_BYTE_DATA | \
|
|
I2C_FUNC_SMBUS_WORD_DATA | \
|
|
I2C_FUNC_SMBUS_PROC_CALL | \
|
|
I2C_FUNC_SMBUS_WRITE_BLOCK_DATA | \
|
|
I2C_FUNC_SMBUS_I2C_BLOCK | \
|
|
I2C_FUNC_SMBUS_PEC)
|
|
|
|
/*
|
|
* Data for SMBus Messages
|
|
*/
|
|
#define I2C_SMBUS_BLOCK_MAX 32 /* As specified in SMBus standard */
|
|
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 user-space compatibility */
|
|
};
|
|
|
|
/* i2c_smbus_xfer 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
|
|
|
|
#endif /* _LINUX_I2C_H */
|