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1da177e4 LT |
1 | /* |
2 | i2c-stub.c - Part of lm_sensors, Linux kernel modules for hardware | |
3 | monitoring | |
4 | ||
5 | Copyright (c) 2004 Mark M. Hoffman <mhoffman@lightlink.com> | |
6 | ||
7 | This program is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 2 of the License, or | |
10 | (at your option) any later version. | |
11 | ||
12 | This program is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with this program; if not, write to the Free Software | |
19 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
20 | */ | |
21 | ||
22 | #define DEBUG 1 | |
23 | ||
24 | #include <linux/config.h> | |
25 | #include <linux/init.h> | |
26 | #include <linux/module.h> | |
27 | #include <linux/kernel.h> | |
28 | #include <linux/errno.h> | |
29 | #include <linux/i2c.h> | |
30 | ||
31 | static u8 stub_pointer; | |
32 | static u8 stub_bytes[256]; | |
33 | static u16 stub_words[256]; | |
34 | ||
35 | /* Return -1 on error. */ | |
36 | static s32 stub_xfer(struct i2c_adapter * adap, u16 addr, unsigned short flags, | |
37 | char read_write, u8 command, int size, union i2c_smbus_data * data) | |
38 | { | |
39 | s32 ret; | |
40 | ||
41 | switch (size) { | |
42 | ||
43 | case I2C_SMBUS_QUICK: | |
44 | dev_dbg(&adap->dev, "smbus quick - addr 0x%02x\n", addr); | |
45 | ret = 0; | |
46 | break; | |
47 | ||
48 | case I2C_SMBUS_BYTE: | |
49 | if (read_write == I2C_SMBUS_WRITE) { | |
50 | stub_pointer = command; | |
51 | dev_dbg(&adap->dev, "smbus byte - addr 0x%02x, " | |
52 | "wrote 0x%02x.\n", | |
53 | addr, command); | |
54 | } else { | |
55 | data->byte = stub_bytes[stub_pointer++]; | |
56 | dev_dbg(&adap->dev, "smbus byte - addr 0x%02x, " | |
57 | "read 0x%02x.\n", | |
58 | addr, data->byte); | |
59 | } | |
60 | ||
61 | ret = 0; | |
62 | break; | |
63 | ||
64 | case I2C_SMBUS_BYTE_DATA: | |
65 | if (read_write == I2C_SMBUS_WRITE) { | |
66 | stub_bytes[command] = data->byte; | |
67 | dev_dbg(&adap->dev, "smbus byte data - addr 0x%02x, " | |
68 | "wrote 0x%02x at 0x%02x.\n", | |
69 | addr, data->byte, command); | |
70 | } else { | |
71 | data->byte = stub_bytes[command]; | |
72 | dev_dbg(&adap->dev, "smbus byte data - addr 0x%02x, " | |
73 | "read 0x%02x at 0x%02x.\n", | |
74 | addr, data->byte, command); | |
75 | } | |
76 | stub_pointer = command + 1; | |
77 | ||
78 | ret = 0; | |
79 | break; | |
80 | ||
81 | case I2C_SMBUS_WORD_DATA: | |
82 | if (read_write == I2C_SMBUS_WRITE) { | |
83 | stub_words[command] = data->word; | |
84 | dev_dbg(&adap->dev, "smbus word data - addr 0x%02x, " | |
85 | "wrote 0x%04x at 0x%02x.\n", | |
86 | addr, data->word, command); | |
87 | } else { | |
88 | data->word = stub_words[command]; | |
89 | dev_dbg(&adap->dev, "smbus word data - addr 0x%02x, " | |
90 | "read 0x%04x at 0x%02x.\n", | |
91 | addr, data->word, command); | |
92 | } | |
93 | ||
94 | ret = 0; | |
95 | break; | |
96 | ||
97 | default: | |
98 | dev_dbg(&adap->dev, "Unsupported I2C/SMBus command\n"); | |
99 | ret = -1; | |
100 | break; | |
101 | } /* switch (size) */ | |
102 | ||
103 | return ret; | |
104 | } | |
105 | ||
106 | static u32 stub_func(struct i2c_adapter *adapter) | |
107 | { | |
108 | return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE | | |
109 | I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA; | |
110 | } | |
111 | ||
112 | static struct i2c_algorithm smbus_algorithm = { | |
113 | .name = "Non-I2C SMBus adapter", | |
114 | .id = I2C_ALGO_SMBUS, | |
115 | .functionality = stub_func, | |
116 | .smbus_xfer = stub_xfer, | |
117 | }; | |
118 | ||
119 | static struct i2c_adapter stub_adapter = { | |
120 | .owner = THIS_MODULE, | |
121 | .class = I2C_CLASS_HWMON, | |
122 | .algo = &smbus_algorithm, | |
123 | .name = "SMBus stub driver", | |
124 | }; | |
125 | ||
126 | static int __init i2c_stub_init(void) | |
127 | { | |
128 | printk(KERN_INFO "i2c-stub loaded\n"); | |
129 | return i2c_add_adapter(&stub_adapter); | |
130 | } | |
131 | ||
132 | static void __exit i2c_stub_exit(void) | |
133 | { | |
134 | i2c_del_adapter(&stub_adapter); | |
135 | } | |
136 | ||
137 | MODULE_AUTHOR("Mark M. Hoffman <mhoffman@lightlink.com>"); | |
138 | MODULE_DESCRIPTION("I2C stub driver"); | |
139 | MODULE_LICENSE("GPL"); | |
140 | ||
141 | module_init(i2c_stub_init); | |
142 | module_exit(i2c_stub_exit); | |
143 |