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i2c-stub: Support multiple chips

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Add support for multiple chips to i2c-stub. I've changed the memory
allocation scheme from static to dynamic, so that we don't waste too
much memory.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Mark M. Hoffman <mhoffman@lightlink.com>
This commit is contained in:
Jean Delvare
2007-10-13 23:56:31 +02:00
committed by Jean Delvare
parent 567a244b8b
commit 9d90c1fd9b
2 changed files with 64 additions and 31 deletions
Download Patch File Download Diff File Expand all files Collapse all files

77
drivers/i2c/busses/i2c-stub.c
View File

@@ -24,24 +24,41 @@
#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)\n");
struct stub_chip {
u8 pointer;
u8 bytes[256];
u16 words[256];
};
static struct stub_chip *stub_chips;
/* Return -1 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;
int i;
struct stub_chip *chip = NULL;
if (addr != chip_addr)
/* 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) {
@@ -53,12 +70,12 @@ static s32 stub_xfer(struct i2c_adapter * adap, u16 addr, unsigned short flags,
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->bytes[chip->pointer++];
dev_dbg(&adap->dev, "smbus byte - addr 0x%02x, "
"read 0x%02x.\n",
addr, data->byte);
@@ -69,29 +86,29 @@ static s32 stub_xfer(struct i2c_adapter * adap, u16 addr, unsigned short flags,
case I2C_SMBUS_BYTE_DATA:
if (read_write == I2C_SMBUS_WRITE) {
stub_bytes[command] = data->byte;
chip->bytes[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->bytes[command];
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);
@@ -129,23 +146,41 @@ static struct i2c_adapter stub_adapter = {
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>");