diff options
Diffstat (limited to 'include/uapi/linux/i2c.h')
| -rw-r--r-- | include/uapi/linux/i2c.h | 128 |
1 files changed, 67 insertions, 61 deletions
diff --git a/include/uapi/linux/i2c.h b/include/uapi/linux/i2c.h index f71a1751cacf..92326ebde350 100644 --- a/include/uapi/linux/i2c.h +++ b/include/uapi/linux/i2c.h @@ -1,29 +1,11 @@ /* 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> */ +/* + * 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 @@ -32,18 +14,41 @@ /** * 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. + * + * @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 @@ -60,40 +65,36 @@ * 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 + * 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). + * adapters which are known to support the specific mangling options they need. */ struct i2c_msg { - __u16 addr; /* slave address */ + __u16 addr; __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 */ +#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 -#define I2C_FUNC_PROTOCOL_MANGLING 0x00000004 /* I2C_M_IGNORE_NAK etc. */ +#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 /* I2C_M_NOSTART */ +#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 */ +#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 @@ -102,11 +103,11 @@ struct i2c_msg { #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_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 +#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) @@ -128,6 +129,11 @@ struct i2c_msg { 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 */ |