/*
- i2c-stub.c - Part of lm_sensors, Linux kernel modules for hardware
- monitoring
+ i2c-stub.c - I2C/SMBus chip emulator
Copyright (c) 2004 Mark M. Hoffman <mhoffman@lightlink.com>
+ Copyright (C) 2007 Jean Delvare <khali@linux-fr.org>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
+#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/i2c.h>
-static unsigned short chip_addr;
-module_param(chip_addr, ushort, S_IRUGO);
-MODULE_PARM_DESC(chip_addr, "Chip address (between 0x03 and 0x77)\n");
+#define MAX_CHIPS 10
-static u8 stub_pointer;
-static u8 stub_bytes[256];
-static u16 stub_words[256];
+static unsigned short chip_addr[MAX_CHIPS];
+module_param_array(chip_addr, ushort, NULL, S_IRUGO);
+MODULE_PARM_DESC(chip_addr,
+ "Chip addresses (up to 10, between 0x03 and 0x77)");
-/* Return -1 on error. */
+struct stub_chip {
+ u8 pointer;
+ u16 words[256]; /* Byte operations use the LSB as per SMBus
+ specification */
+};
+
+static struct stub_chip *stub_chips;
+
+/* Return negative errno on error. */
static s32 stub_xfer(struct i2c_adapter * adap, u16 addr, unsigned short flags,
char read_write, u8 command, int size, union i2c_smbus_data * data)
{
s32 ret;
-
- if (addr != chip_addr)
+ int i;
+ struct stub_chip *chip = NULL;
+
+ /* Search for the right chip */
+ for (i = 0; i < MAX_CHIPS && chip_addr[i]; i++) {
+ if (addr == chip_addr[i]) {
+ chip = stub_chips + i;
+ break;
+ }
+ }
+ if (!chip)
return -ENODEV;
switch (size) {
case I2C_SMBUS_BYTE:
if (read_write == I2C_SMBUS_WRITE) {
- stub_pointer = command;
+ chip->pointer = command;
dev_dbg(&adap->dev, "smbus byte - addr 0x%02x, "
"wrote 0x%02x.\n",
addr, command);
} else {
- data->byte = stub_bytes[stub_pointer++];
+ data->byte = chip->words[chip->pointer++] & 0xff;
dev_dbg(&adap->dev, "smbus byte - addr 0x%02x, "
"read 0x%02x.\n",
addr, data->byte);
case I2C_SMBUS_BYTE_DATA:
if (read_write == I2C_SMBUS_WRITE) {
- stub_bytes[command] = data->byte;
+ chip->words[command] &= 0xff00;
+ chip->words[command] |= data->byte;
dev_dbg(&adap->dev, "smbus byte data - addr 0x%02x, "
"wrote 0x%02x at 0x%02x.\n",
addr, data->byte, command);
} else {
- data->byte = stub_bytes[command];
+ data->byte = chip->words[command] & 0xff;
dev_dbg(&adap->dev, "smbus byte data - addr 0x%02x, "
"read 0x%02x at 0x%02x.\n",
addr, data->byte, command);
}
- stub_pointer = command + 1;
+ chip->pointer = command + 1;
ret = 0;
break;
case I2C_SMBUS_WORD_DATA:
if (read_write == I2C_SMBUS_WRITE) {
- stub_words[command] = data->word;
+ chip->words[command] = data->word;
dev_dbg(&adap->dev, "smbus word data - addr 0x%02x, "
"wrote 0x%04x at 0x%02x.\n",
addr, data->word, command);
} else {
- data->word = stub_words[command];
+ data->word = chip->words[command];
dev_dbg(&adap->dev, "smbus word data - addr 0x%02x, "
"read 0x%04x at 0x%02x.\n",
addr, data->word, command);
default:
dev_dbg(&adap->dev, "Unsupported I2C/SMBus command\n");
- ret = -1;
+ ret = -EOPNOTSUPP;
break;
} /* switch (size) */
static struct i2c_adapter stub_adapter = {
.owner = THIS_MODULE,
- .class = I2C_CLASS_HWMON,
+ .class = I2C_CLASS_HWMON | I2C_CLASS_SPD,
.algo = &smbus_algorithm,
.name = "SMBus stub driver",
};
static int __init i2c_stub_init(void)
{
- if (!chip_addr) {
+ int i, ret;
+
+ if (!chip_addr[0]) {
printk(KERN_ERR "i2c-stub: Please specify a chip address\n");
return -ENODEV;
}
- if (chip_addr < 0x03 || chip_addr > 0x77) {
- printk(KERN_ERR "i2c-stub: Invalid chip address 0x%02x\n",
- chip_addr);
- return -EINVAL;
+
+ for (i = 0; i < MAX_CHIPS && chip_addr[i]; i++) {
+ if (chip_addr[i] < 0x03 || chip_addr[i] > 0x77) {
+ printk(KERN_ERR "i2c-stub: Invalid chip address "
+ "0x%02x\n", chip_addr[i]);
+ return -EINVAL;
+ }
+
+ printk(KERN_INFO "i2c-stub: Virtual chip at 0x%02x\n",
+ chip_addr[i]);
}
- printk(KERN_INFO "i2c-stub: Virtual chip at 0x%02x\n", chip_addr);
- return i2c_add_adapter(&stub_adapter);
+ /* Allocate memory for all chips at once */
+ stub_chips = kzalloc(i * sizeof(struct stub_chip), GFP_KERNEL);
+ if (!stub_chips) {
+ printk(KERN_ERR "i2c-stub: Out of memory\n");
+ return -ENOMEM;
+ }
+
+ ret = i2c_add_adapter(&stub_adapter);
+ if (ret)
+ kfree(stub_chips);
+ return ret;
}
static void __exit i2c_stub_exit(void)
{
i2c_del_adapter(&stub_adapter);
+ kfree(stub_chips);
}
MODULE_AUTHOR("Mark M. Hoffman <mhoffman@lightlink.com>");
git.openpandora.org / pandora-kernel.git / blobdiff