June 2025 | ||||||
Mo | Tu | We | Th | Fr | Sa | Su |
26 | 27 | 28 | 29 | 30 | 31 | 1 |
2 | 3 | 4 | 5 | 6 | 7 | 8 |
9 | 10 | 11 | 12 | 13 | 14 | 15 |
16 | 17 | 18 | 19 | 20 | 21 | 22 |
23 | 24 | 25 | 26 | 27 | 28 | 29 |
30 | 1 | 2 | 3 | 4 | 5 | 6 |
001: /* ------------------------------------------------------------------------- */ 002: /* */ 003: /* i2c.h - definitions for the i2c-bus interface */ 004: /* */ 005: /* ------------------------------------------------------------------------- */ 006: /* Copyright (C) 1995-2000 Simon G. Vogl 007: 008: This program is free software; you can redistribute it and/or modify 009: it under the terms of the GNU General Public License as published by 010: the Free Software Foundation; either version 2 of the License, or 011: (at your option) any later version. 012: 013: This program is distributed in the hope that it will be useful, 014: but WITHOUT ANY WARRANTY; without even the implied warranty of 015: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 016: GNU General Public License for more details. 017: 018: You should have received a copy of the GNU General Public License 019: along with this program; if not, write to the Free Software 020: Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ 021: /* ------------------------------------------------------------------------- */ 022: 023: /* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and 024: Frodo Looijaard <frodol@dds.nl> */ 025: 026: #ifndef _LINUX_I2C_H 027: #define _LINUX_I2C_H 028: 029: #include <linux/types.h> 030: 031: /** 032: * struct i2c_msg - an I2C transaction segment beginning with START 033: * @addr: Slave address, either seven or ten bits. When this is a ten 034: * bit address, I2C_M_TEN must be set in @flags and the adapter 035: * must support I2C_FUNC_10BIT_ADDR. 036: * @flags: I2C_M_RD is handled by all adapters. No other flags may be 037: * provided unless the adapter exported the relevant I2C_FUNC_* 038: * flags through i2c_check_functionality(). 039: * @len: Number of data bytes in @buf being read from or written to the 040: * I2C slave address. For read transactions where I2C_M_RECV_LEN 041: * is set, the caller guarantees that this buffer can hold up to 042: * 32 bytes in addition to the initial length byte sent by the 043: * slave (plus, if used, the SMBus PEC); and this value will be 044: * incremented by the number of block data bytes received. 045: * @buf: The buffer into which data is read, or from which it's written. 046: * 047: * An i2c_msg is the low level representation of one segment of an I2C 048: * transaction. It is visible to drivers in the @i2c_transfer() procedure, 049: * to userspace from i2c-dev, and to I2C adapter drivers through the 050: * @i2c_adapter.@master_xfer() method. 051: * 052: * Except when I2C "protocol mangling" is used, all I2C adapters implement 053: * the standard rules for I2C transactions. Each transaction begins with a 054: * START. That is followed by the slave address, and a bit encoding read 055: * versus write. Then follow all the data bytes, possibly including a byte 056: * with SMBus PEC. The transfer terminates with a NAK, or when all those 057: * bytes have been transferred and ACKed. If this is the last message in a 058: * group, it is followed by a STOP. Otherwise it is followed by the next 059: * @i2c_msg transaction segment, beginning with a (repeated) START. 060: * 061: * Alternatively, when the adapter supports I2C_FUNC_PROTOCOL_MANGLING then 062: * passing certain @flags may have changed those standard protocol behaviors. 063: * Those flags are only for use with broken/nonconforming slaves, and with 064: * adapters which are known to support the specific mangling options they 065: * need (one or more of IGNORE_NAK, NO_RD_ACK, NOSTART, and REV_DIR_ADDR). 066: */ 067: struct i2c_msg { 068: __u16 addr; /* slave address */ 069: __u16 flags; 070: #define I2C_M_TEN 0x0010 /* this is a ten bit chip address */ 071: #define I2C_M_RD 0x0001 /* read data, from slave to master */ 072: #define I2C_M_NOSTART 0x4000 /* if I2C_FUNC_PROTOCOL_MANGLING */ 073: #define I2C_M_REV_DIR_ADDR 0x2000 /* if I2C_FUNC_PROTOCOL_MANGLING */ 074: #define I2C_M_IGNORE_NAK 0x1000 /* if I2C_FUNC_PROTOCOL_MANGLING */ 075: #define I2C_M_NO_RD_ACK 0x0800 /* if I2C_FUNC_PROTOCOL_MANGLING */ 076: #define I2C_M_RECV_LEN 0x0400 /* length will be first received byte */ 077: __u16 len; /* msg length */ 078: __u8 *buf; /* pointer to msg data */ 079: }; 080: 081: /* To determine what functionality is present */ 082: 083: #define I2C_FUNC_I2C 0x00000001 084: #define I2C_FUNC_10BIT_ADDR 0x00000002 085: #define I2C_FUNC_PROTOCOL_MANGLING 0x00000004 /* I2C_M_NOSTART etc. */ 086: #define I2C_FUNC_SMBUS_PEC 0x00000008 087: #define I2C_FUNC_SMBUS_BLOCK_PROC_CALL 0x00008000 /* SMBus 2.0 */ 088: #define I2C_FUNC_SMBUS_QUICK 0x00010000 089: #define I2C_FUNC_SMBUS_READ_BYTE 0x00020000 090: #define I2C_FUNC_SMBUS_WRITE_BYTE 0x00040000 091: #define I2C_FUNC_SMBUS_READ_BYTE_DATA 0x00080000 092: #define I2C_FUNC_SMBUS_WRITE_BYTE_DATA 0x00100000 093: #define I2C_FUNC_SMBUS_READ_WORD_DATA 0x00200000 094: #define I2C_FUNC_SMBUS_WRITE_WORD_DATA 0x00400000 095: #define I2C_FUNC_SMBUS_PROC_CALL 0x00800000 096: #define I2C_FUNC_SMBUS_READ_BLOCK_DATA 0x01000000 097: #define I2C_FUNC_SMBUS_WRITE_BLOCK_DATA 0x02000000 098: #define I2C_FUNC_SMBUS_READ_I2C_BLOCK 0x04000000 /* I2C-like block xfer */ 099: #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 */ 149: