--- /dev/null
+/* 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 */
projects / cross.git / blobdiff