]>
Commit | Line | Data |
---|---|---|
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 | ||
1da177e4 LT |
24 | #include <linux/init.h> |
25 | #include <linux/module.h> | |
26 | #include <linux/kernel.h> | |
27 | #include <linux/errno.h> | |
28 | #include <linux/i2c.h> | |
29 | ||
7a8d29ce JD |
30 | static unsigned short chip_addr; |
31 | module_param(chip_addr, ushort, S_IRUGO); | |
32 | MODULE_PARM_DESC(chip_addr, "Chip address (between 0x03 and 0x77)\n"); | |
33 | ||
1da177e4 LT |
34 | static u8 stub_pointer; |
35 | static u8 stub_bytes[256]; | |
36 | static u16 stub_words[256]; | |
37 | ||
38 | /* Return -1 on error. */ | |
39 | static s32 stub_xfer(struct i2c_adapter * adap, u16 addr, unsigned short flags, | |
40 | char read_write, u8 command, int size, union i2c_smbus_data * data) | |
41 | { | |
42 | s32 ret; | |
43 | ||
7a8d29ce JD |
44 | if (addr != chip_addr) |
45 | return -ENODEV; | |
46 | ||
1da177e4 LT |
47 | switch (size) { |
48 | ||
49 | case I2C_SMBUS_QUICK: | |
50 | dev_dbg(&adap->dev, "smbus quick - addr 0x%02x\n", addr); | |
51 | ret = 0; | |
52 | break; | |
53 | ||
54 | case I2C_SMBUS_BYTE: | |
55 | if (read_write == I2C_SMBUS_WRITE) { | |
56 | stub_pointer = command; | |
57 | dev_dbg(&adap->dev, "smbus byte - addr 0x%02x, " | |
58 | "wrote 0x%02x.\n", | |
59 | addr, command); | |
60 | } else { | |
61 | data->byte = stub_bytes[stub_pointer++]; | |
62 | dev_dbg(&adap->dev, "smbus byte - addr 0x%02x, " | |
63 | "read 0x%02x.\n", | |
64 | addr, data->byte); | |
65 | } | |
66 | ||
67 | ret = 0; | |
68 | break; | |
69 | ||
70 | case I2C_SMBUS_BYTE_DATA: | |
71 | if (read_write == I2C_SMBUS_WRITE) { | |
72 | stub_bytes[command] = data->byte; | |
73 | dev_dbg(&adap->dev, "smbus byte data - addr 0x%02x, " | |
74 | "wrote 0x%02x at 0x%02x.\n", | |
75 | addr, data->byte, command); | |
76 | } else { | |
77 | data->byte = stub_bytes[command]; | |
78 | dev_dbg(&adap->dev, "smbus byte data - addr 0x%02x, " | |
79 | "read 0x%02x at 0x%02x.\n", | |
80 | addr, data->byte, command); | |
81 | } | |
82 | stub_pointer = command + 1; | |
83 | ||
84 | ret = 0; | |
85 | break; | |
86 | ||
87 | case I2C_SMBUS_WORD_DATA: | |
88 | if (read_write == I2C_SMBUS_WRITE) { | |
89 | stub_words[command] = data->word; | |
90 | dev_dbg(&adap->dev, "smbus word data - addr 0x%02x, " | |
91 | "wrote 0x%04x at 0x%02x.\n", | |
92 | addr, data->word, command); | |
93 | } else { | |
94 | data->word = stub_words[command]; | |
95 | dev_dbg(&adap->dev, "smbus word data - addr 0x%02x, " | |
96 | "read 0x%04x at 0x%02x.\n", | |
97 | addr, data->word, command); | |
98 | } | |
99 | ||
100 | ret = 0; | |
101 | break; | |
102 | ||
103 | default: | |
104 | dev_dbg(&adap->dev, "Unsupported I2C/SMBus command\n"); | |
105 | ret = -1; | |
106 | break; | |
107 | } /* switch (size) */ | |
108 | ||
109 | return ret; | |
110 | } | |
111 | ||
112 | static u32 stub_func(struct i2c_adapter *adapter) | |
113 | { | |
114 | return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE | | |
115 | I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA; | |
116 | } | |
117 | ||
118 | static struct i2c_algorithm smbus_algorithm = { | |
1da177e4 LT |
119 | .functionality = stub_func, |
120 | .smbus_xfer = stub_xfer, | |
121 | }; | |
122 | ||
123 | static struct i2c_adapter stub_adapter = { | |
124 | .owner = THIS_MODULE, | |
125 | .class = I2C_CLASS_HWMON, | |
126 | .algo = &smbus_algorithm, | |
127 | .name = "SMBus stub driver", | |
128 | }; | |
129 | ||
130 | static int __init i2c_stub_init(void) | |
131 | { | |
7a8d29ce JD |
132 | if (!chip_addr) { |
133 | printk(KERN_ERR "i2c-stub: Please specify a chip address\n"); | |
134 | return -ENODEV; | |
135 | } | |
136 | if (chip_addr < 0x03 || chip_addr > 0x77) { | |
137 | printk(KERN_ERR "i2c-stub: Invalid chip address 0x%02x\n", | |
138 | chip_addr); | |
139 | return -EINVAL; | |
140 | } | |
141 | ||
142 | printk(KERN_INFO "i2c-stub: Virtual chip at 0x%02x\n", chip_addr); | |
1da177e4 LT |
143 | return i2c_add_adapter(&stub_adapter); |
144 | } | |
145 | ||
146 | static void __exit i2c_stub_exit(void) | |
147 | { | |
148 | i2c_del_adapter(&stub_adapter); | |
149 | } | |
150 | ||
151 | MODULE_AUTHOR("Mark M. Hoffman <mhoffman@lightlink.com>"); | |
152 | MODULE_DESCRIPTION("I2C stub driver"); | |
153 | MODULE_LICENSE("GPL"); | |
154 | ||
155 | module_init(i2c_stub_init); | |
156 | module_exit(i2c_stub_exit); | |
157 |