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607ca46e DH |
1 | /* ------------------------------------------------------------------------- */ |
2 | /* */ | |
3 | /* i2c.h - definitions for the i2c-bus interface */ | |
4 | /* */ | |
5 | /* ------------------------------------------------------------------------- */ | |
6 | /* Copyright (C) 1995-2000 Simon G. Vogl | |
7 | ||
8 | This program is free software; you can redistribute it and/or modify | |
9 | it under the terms of the GNU General Public License as published by | |
10 | the Free Software Foundation; either version 2 of the License, or | |
11 | (at your option) any later version. | |
12 | ||
13 | This program is distributed in the hope that it will be useful, | |
14 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | GNU General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
19 | along with this program; if not, write to the Free Software | |
20 | Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, | |
21 | MA 02110-1301 USA. */ | |
22 | /* ------------------------------------------------------------------------- */ | |
23 | ||
24 | /* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and | |
25 | Frodo Looijaard <frodol@dds.nl> */ | |
26 | ||
27 | #ifndef _UAPI_LINUX_I2C_H | |
28 | #define _UAPI_LINUX_I2C_H | |
29 | ||
30 | #include <linux/types.h> | |
31 | ||
32 | /** | |
33 | * struct i2c_msg - an I2C transaction segment beginning with START | |
34 | * @addr: Slave address, either seven or ten bits. When this is a ten | |
35 | * bit address, I2C_M_TEN must be set in @flags and the adapter | |
36 | * must support I2C_FUNC_10BIT_ADDR. | |
37 | * @flags: I2C_M_RD is handled by all adapters. No other flags may be | |
38 | * provided unless the adapter exported the relevant I2C_FUNC_* | |
39 | * flags through i2c_check_functionality(). | |
40 | * @len: Number of data bytes in @buf being read from or written to the | |
41 | * I2C slave address. For read transactions where I2C_M_RECV_LEN | |
42 | * is set, the caller guarantees that this buffer can hold up to | |
43 | * 32 bytes in addition to the initial length byte sent by the | |
44 | * slave (plus, if used, the SMBus PEC); and this value will be | |
45 | * incremented by the number of block data bytes received. | |
46 | * @buf: The buffer into which data is read, or from which it's written. | |
47 | * | |
48 | * An i2c_msg is the low level representation of one segment of an I2C | |
49 | * transaction. It is visible to drivers in the @i2c_transfer() procedure, | |
50 | * to userspace from i2c-dev, and to I2C adapter drivers through the | |
51 | * @i2c_adapter.@master_xfer() method. | |
52 | * | |
53 | * Except when I2C "protocol mangling" is used, all I2C adapters implement | |
54 | * the standard rules for I2C transactions. Each transaction begins with a | |
55 | * START. That is followed by the slave address, and a bit encoding read | |
56 | * versus write. Then follow all the data bytes, possibly including a byte | |
57 | * with SMBus PEC. The transfer terminates with a NAK, or when all those | |
58 | * bytes have been transferred and ACKed. If this is the last message in a | |
59 | * group, it is followed by a STOP. Otherwise it is followed by the next | |
60 | * @i2c_msg transaction segment, beginning with a (repeated) START. | |
61 | * | |
62 | * Alternatively, when the adapter supports I2C_FUNC_PROTOCOL_MANGLING then | |
63 | * passing certain @flags may have changed those standard protocol behaviors. | |
64 | * Those flags are only for use with broken/nonconforming slaves, and with | |
65 | * adapters which are known to support the specific mangling options they | |
66 | * need (one or more of IGNORE_NAK, NO_RD_ACK, NOSTART, and REV_DIR_ADDR). | |
67 | */ | |
68 | struct i2c_msg { | |
69 | __u16 addr; /* slave address */ | |
70 | __u16 flags; | |
607ca46e | 71 | #define I2C_M_RD 0x0001 /* read data, from slave to master */ |
e28b1245 WS |
72 | /* I2C_M_RD is guaranteed to be 0x0001! */ |
73 | #define I2C_M_TEN 0x0010 /* this is a ten bit chip address */ | |
607ca46e | 74 | #define I2C_M_RECV_LEN 0x0400 /* length will be first received byte */ |
e28b1245 WS |
75 | #define I2C_M_NO_RD_ACK 0x0800 /* if I2C_FUNC_PROTOCOL_MANGLING */ |
76 | #define I2C_M_IGNORE_NAK 0x1000 /* if I2C_FUNC_PROTOCOL_MANGLING */ | |
77 | #define I2C_M_REV_DIR_ADDR 0x2000 /* if I2C_FUNC_PROTOCOL_MANGLING */ | |
78 | #define I2C_M_NOSTART 0x4000 /* if I2C_FUNC_NOSTART */ | |
79 | #define I2C_M_STOP 0x8000 /* if I2C_FUNC_PROTOCOL_MANGLING */ | |
607ca46e DH |
80 | __u16 len; /* msg length */ |
81 | __u8 *buf; /* pointer to msg data */ | |
82 | }; | |
83 | ||
84 | /* To determine what functionality is present */ | |
85 | ||
86 | #define I2C_FUNC_I2C 0x00000001 | |
87 | #define I2C_FUNC_10BIT_ADDR 0x00000002 | |
88 | #define I2C_FUNC_PROTOCOL_MANGLING 0x00000004 /* I2C_M_IGNORE_NAK etc. */ | |
89 | #define I2C_FUNC_SMBUS_PEC 0x00000008 | |
90 | #define I2C_FUNC_NOSTART 0x00000010 /* I2C_M_NOSTART */ | |
83caf989 | 91 | #define I2C_FUNC_SLAVE 0x00000020 |
607ca46e DH |
92 | #define I2C_FUNC_SMBUS_BLOCK_PROC_CALL 0x00008000 /* SMBus 2.0 */ |
93 | #define I2C_FUNC_SMBUS_QUICK 0x00010000 | |
94 | #define I2C_FUNC_SMBUS_READ_BYTE 0x00020000 | |
95 | #define I2C_FUNC_SMBUS_WRITE_BYTE 0x00040000 | |
96 | #define I2C_FUNC_SMBUS_READ_BYTE_DATA 0x00080000 | |
97 | #define I2C_FUNC_SMBUS_WRITE_BYTE_DATA 0x00100000 | |
98 | #define I2C_FUNC_SMBUS_READ_WORD_DATA 0x00200000 | |
99 | #define I2C_FUNC_SMBUS_WRITE_WORD_DATA 0x00400000 | |
100 | #define I2C_FUNC_SMBUS_PROC_CALL 0x00800000 | |
101 | #define I2C_FUNC_SMBUS_READ_BLOCK_DATA 0x01000000 | |
102 | #define I2C_FUNC_SMBUS_WRITE_BLOCK_DATA 0x02000000 | |
103 | #define I2C_FUNC_SMBUS_READ_I2C_BLOCK 0x04000000 /* I2C-like block xfer */ | |
104 | #define I2C_FUNC_SMBUS_WRITE_I2C_BLOCK 0x08000000 /* w/ 1-byte reg. addr. */ | |
105 | ||
106 | #define I2C_FUNC_SMBUS_BYTE (I2C_FUNC_SMBUS_READ_BYTE | \ | |
107 | I2C_FUNC_SMBUS_WRITE_BYTE) | |
108 | #define I2C_FUNC_SMBUS_BYTE_DATA (I2C_FUNC_SMBUS_READ_BYTE_DATA | \ | |
109 | I2C_FUNC_SMBUS_WRITE_BYTE_DATA) | |
110 | #define I2C_FUNC_SMBUS_WORD_DATA (I2C_FUNC_SMBUS_READ_WORD_DATA | \ | |
111 | I2C_FUNC_SMBUS_WRITE_WORD_DATA) | |
112 | #define I2C_FUNC_SMBUS_BLOCK_DATA (I2C_FUNC_SMBUS_READ_BLOCK_DATA | \ | |
113 | I2C_FUNC_SMBUS_WRITE_BLOCK_DATA) | |
114 | #define I2C_FUNC_SMBUS_I2C_BLOCK (I2C_FUNC_SMBUS_READ_I2C_BLOCK | \ | |
115 | I2C_FUNC_SMBUS_WRITE_I2C_BLOCK) | |
116 | ||
117 | #define I2C_FUNC_SMBUS_EMUL (I2C_FUNC_SMBUS_QUICK | \ | |
118 | I2C_FUNC_SMBUS_BYTE | \ | |
119 | I2C_FUNC_SMBUS_BYTE_DATA | \ | |
120 | I2C_FUNC_SMBUS_WORD_DATA | \ | |
121 | I2C_FUNC_SMBUS_PROC_CALL | \ | |
122 | I2C_FUNC_SMBUS_WRITE_BLOCK_DATA | \ | |
123 | I2C_FUNC_SMBUS_I2C_BLOCK | \ | |
124 | I2C_FUNC_SMBUS_PEC) | |
125 | ||
126 | /* | |
127 | * Data for SMBus Messages | |
128 | */ | |
129 | #define I2C_SMBUS_BLOCK_MAX 32 /* As specified in SMBus standard */ | |
130 | union i2c_smbus_data { | |
131 | __u8 byte; | |
132 | __u16 word; | |
133 | __u8 block[I2C_SMBUS_BLOCK_MAX + 2]; /* block[0] is used for length */ | |
134 | /* and one more for user-space compatibility */ | |
135 | }; | |
136 | ||
137 | /* i2c_smbus_xfer read or write markers */ | |
138 | #define I2C_SMBUS_READ 1 | |
139 | #define I2C_SMBUS_WRITE 0 | |
140 | ||
141 | /* SMBus transaction types (size parameter in the above functions) | |
142 | Note: these no longer correspond to the (arbitrary) PIIX4 internal codes! */ | |
143 | #define I2C_SMBUS_QUICK 0 | |
144 | #define I2C_SMBUS_BYTE 1 | |
145 | #define I2C_SMBUS_BYTE_DATA 2 | |
146 | #define I2C_SMBUS_WORD_DATA 3 | |
147 | #define I2C_SMBUS_PROC_CALL 4 | |
148 | #define I2C_SMBUS_BLOCK_DATA 5 | |
149 | #define I2C_SMBUS_I2C_BLOCK_BROKEN 6 | |
150 | #define I2C_SMBUS_BLOCK_PROC_CALL 7 /* SMBus 2.0 */ | |
151 | #define I2C_SMBUS_I2C_BLOCK_DATA 8 | |
152 | ||
153 | #endif /* _UAPI_LINUX_I2C_H */ |