projects / deliverable / linux.git / blame
| 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 | ||
| 8f9082c5 | 118 | static const 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 |