You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
165 lines
6.7 KiB
165 lines
6.7 KiB
/* 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
|
|
* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and
|
|
* Frodo Looijaard <frodol@dds.nl>
|
|
*/
|
|
|
|
#ifndef _UAPI_LINUX_I2C_H
|
|
#define _UAPI_LINUX_I2C_H
|
|
|
|
#include <linux/types.h>
|
|
|
|
/**
|
|
* struct i2c_msg - an I2C transaction segment beginning with START
|
|
*
|
|
* @addr: Slave address, either 7 or 10 bits. When this is a 10 bit address,
|
|
* %I2C_M_TEN must be set in @flags and the adapter must support
|
|
* %I2C_FUNC_10BIT_ADDR.
|
|
*
|
|
* @flags:
|
|
* Supported by all adapters:
|
|
* %I2C_M_RD: read data (from slave to master). Guaranteed to be 0x0001!
|
|
*
|
|
* Optional:
|
|
* %I2C_M_DMA_SAFE: the buffer of this message is DMA safe. Makes only sense
|
|
* in kernelspace, because userspace buffers are copied anyway
|
|
*
|
|
* Only if I2C_FUNC_10BIT_ADDR is set:
|
|
* %I2C_M_TEN: this is a 10 bit chip address
|
|
*
|
|
* Only if I2C_FUNC_SMBUS_READ_BLOCK_DATA is set:
|
|
* %I2C_M_RECV_LEN: message length will be first received byte
|
|
*
|
|
* Only if I2C_FUNC_NOSTART is set:
|
|
* %I2C_M_NOSTART: skip repeated start sequence
|
|
|
|
* Only if I2C_FUNC_PROTOCOL_MANGLING is set:
|
|
* %I2C_M_NO_RD_ACK: in a read message, master ACK/NACK bit is skipped
|
|
* %I2C_M_IGNORE_NAK: treat NACK from client as ACK
|
|
* %I2C_M_REV_DIR_ADDR: toggles the Rd/Wr bit
|
|
* %I2C_M_STOP: force a STOP condition after the message
|
|
*
|
|
* @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 %I2C_SMBUS_BLOCK_MAX
|
|
* 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.
|
|
*/
|
|
struct i2c_msg {
|
|
__u16 addr;
|
|
__u16 flags;
|
|
#define I2C_M_RD 0x0001 /* guaranteed to be 0x0001! */
|
|
#define I2C_M_TEN 0x0010 /* use only if I2C_FUNC_10BIT_ADDR */
|
|
#define I2C_M_DMA_SAFE 0x0200 /* use only in kernel space */
|
|
#define I2C_M_RECV_LEN 0x0400 /* use only if I2C_FUNC_SMBUS_READ_BLOCK_DATA */
|
|
#define I2C_M_NO_RD_ACK 0x0800 /* use only if I2C_FUNC_PROTOCOL_MANGLING */
|
|
#define I2C_M_IGNORE_NAK 0x1000 /* use only if I2C_FUNC_PROTOCOL_MANGLING */
|
|
#define I2C_M_REV_DIR_ADDR 0x2000 /* use only if I2C_FUNC_PROTOCOL_MANGLING */
|
|
#define I2C_M_NOSTART 0x4000 /* use only if I2C_FUNC_NOSTART */
|
|
#define I2C_M_STOP 0x8000 /* use only if I2C_FUNC_PROTOCOL_MANGLING */
|
|
__u16 len;
|
|
__u8 *buf;
|
|
};
|
|
|
|
/* To determine what functionality is present */
|
|
|
|
#define I2C_FUNC_I2C 0x00000001
|
|
#define I2C_FUNC_10BIT_ADDR 0x00000002 /* required for I2C_M_TEN */
|
|
#define I2C_FUNC_PROTOCOL_MANGLING 0x00000004 /* required for I2C_M_IGNORE_NAK etc. */
|
|
#define I2C_FUNC_SMBUS_PEC 0x00000008
|
|
#define I2C_FUNC_NOSTART 0x00000010 /* required for I2C_M_NOSTART */
|
|
#define I2C_FUNC_SLAVE 0x00000020
|
|
#define I2C_FUNC_SMBUS_BLOCK_PROC_CALL 0x00008000 /* SMBus 2.0 or later */
|
|
#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 /* required for I2C_M_RECV_LEN */
|
|
#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 /* SMBus 2.0 or later */
|
|
|
|
#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)
|
|
|
|
/* if I2C_M_RECV_LEN is also supported */
|
|
#define I2C_FUNC_SMBUS_EMUL_ALL (I2C_FUNC_SMBUS_EMUL | \
|
|
I2C_FUNC_SMBUS_READ_BLOCK_DATA | \
|
|
I2C_FUNC_SMBUS_BLOCK_PROC_CALL)
|
|
|
|
/*
|
|
* 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 /* _UAPI_LINUX_I2C_H */
|