141 lines
3.5 KiB
C
141 lines
3.5 KiB
C
/*
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i2c-stub.c - Part of lm_sensors, Linux kernel modules for hardware
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monitoring
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Copyright (c) 2004 Mark M. Hoffman <mhoffman@lightlink.com>
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#define DEBUG 1
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/i2c.h>
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static u8 stub_pointer;
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static u8 stub_bytes[256];
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static u16 stub_words[256];
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/* Return -1 on error. */
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static s32 stub_xfer(struct i2c_adapter * adap, u16 addr, unsigned short flags,
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char read_write, u8 command, int size, union i2c_smbus_data * data)
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{
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s32 ret;
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switch (size) {
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case I2C_SMBUS_QUICK:
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dev_dbg(&adap->dev, "smbus quick - addr 0x%02x\n", addr);
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ret = 0;
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break;
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case I2C_SMBUS_BYTE:
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if (read_write == I2C_SMBUS_WRITE) {
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stub_pointer = command;
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dev_dbg(&adap->dev, "smbus byte - addr 0x%02x, "
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"wrote 0x%02x.\n",
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addr, command);
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} else {
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data->byte = stub_bytes[stub_pointer++];
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dev_dbg(&adap->dev, "smbus byte - addr 0x%02x, "
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"read 0x%02x.\n",
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addr, data->byte);
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}
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ret = 0;
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break;
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case I2C_SMBUS_BYTE_DATA:
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if (read_write == I2C_SMBUS_WRITE) {
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stub_bytes[command] = data->byte;
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dev_dbg(&adap->dev, "smbus byte data - addr 0x%02x, "
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"wrote 0x%02x at 0x%02x.\n",
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addr, data->byte, command);
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} else {
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data->byte = stub_bytes[command];
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dev_dbg(&adap->dev, "smbus byte data - addr 0x%02x, "
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"read 0x%02x at 0x%02x.\n",
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addr, data->byte, command);
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}
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stub_pointer = command + 1;
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ret = 0;
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break;
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case I2C_SMBUS_WORD_DATA:
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if (read_write == I2C_SMBUS_WRITE) {
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stub_words[command] = data->word;
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dev_dbg(&adap->dev, "smbus word data - addr 0x%02x, "
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"wrote 0x%04x at 0x%02x.\n",
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addr, data->word, command);
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} else {
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data->word = stub_words[command];
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dev_dbg(&adap->dev, "smbus word data - addr 0x%02x, "
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"read 0x%04x at 0x%02x.\n",
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addr, data->word, command);
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}
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ret = 0;
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break;
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default:
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dev_dbg(&adap->dev, "Unsupported I2C/SMBus command\n");
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ret = -1;
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break;
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} /* switch (size) */
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return ret;
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}
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static u32 stub_func(struct i2c_adapter *adapter)
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{
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return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
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I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA;
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}
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static struct i2c_algorithm smbus_algorithm = {
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.functionality = stub_func,
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.smbus_xfer = stub_xfer,
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};
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static struct i2c_adapter stub_adapter = {
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.owner = THIS_MODULE,
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.class = I2C_CLASS_HWMON,
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.algo = &smbus_algorithm,
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.name = "SMBus stub driver",
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};
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static int __init i2c_stub_init(void)
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{
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printk(KERN_INFO "i2c-stub loaded\n");
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return i2c_add_adapter(&stub_adapter);
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}
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static void __exit i2c_stub_exit(void)
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{
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i2c_del_adapter(&stub_adapter);
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}
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MODULE_AUTHOR("Mark M. Hoffman <mhoffman@lightlink.com>");
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MODULE_DESCRIPTION("I2C stub driver");
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MODULE_LICENSE("GPL");
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module_init(i2c_stub_init);
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module_exit(i2c_stub_exit);
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