271 lines
7.2 KiB
C
271 lines
7.2 KiB
C
/*
|
|
eeprom.c - Part of lm_sensors, Linux kernel modules for hardware
|
|
monitoring
|
|
Copyright (C) 1998, 1999 Frodo Looijaard <frodol@dds.nl> and
|
|
Philip Edelbrock <phil@netroedge.com>
|
|
Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com>
|
|
Copyright (C) 2003 IBM Corp.
|
|
|
|
2004-01-16 Jean Delvare <khali@linux-fr.org>
|
|
Divide the eeprom in 32-byte (arbitrary) slices. This significantly
|
|
speeds sensors up, as well as various scripts using the eeprom
|
|
module.
|
|
|
|
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
|
|
the Free Software Foundation; either version 2 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program; if not, write to the Free Software
|
|
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/init.h>
|
|
#include <linux/module.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/jiffies.h>
|
|
#include <linux/i2c.h>
|
|
#include <linux/mutex.h>
|
|
|
|
/* Addresses to scan */
|
|
static const unsigned short normal_i2c[] = { 0x50, 0x51, 0x52, 0x53, 0x54,
|
|
0x55, 0x56, 0x57, I2C_CLIENT_END };
|
|
|
|
/* Insmod parameters */
|
|
I2C_CLIENT_INSMOD_1(eeprom);
|
|
|
|
|
|
/* Size of EEPROM in bytes */
|
|
#define EEPROM_SIZE 256
|
|
|
|
/* possible types of eeprom devices */
|
|
enum eeprom_nature {
|
|
UNKNOWN,
|
|
VAIO,
|
|
};
|
|
|
|
/* Each client has this additional data */
|
|
struct eeprom_data {
|
|
struct i2c_client client;
|
|
struct mutex update_lock;
|
|
u8 valid; /* bitfield, bit!=0 if slice is valid */
|
|
unsigned long last_updated[8]; /* In jiffies, 8 slices */
|
|
u8 data[EEPROM_SIZE]; /* Register values */
|
|
enum eeprom_nature nature;
|
|
};
|
|
|
|
|
|
static int eeprom_attach_adapter(struct i2c_adapter *adapter);
|
|
static int eeprom_detect(struct i2c_adapter *adapter, int address, int kind);
|
|
static int eeprom_detach_client(struct i2c_client *client);
|
|
|
|
/* This is the driver that will be inserted */
|
|
static struct i2c_driver eeprom_driver = {
|
|
.driver = {
|
|
.name = "eeprom",
|
|
},
|
|
.attach_adapter = eeprom_attach_adapter,
|
|
.detach_client = eeprom_detach_client,
|
|
};
|
|
|
|
static void eeprom_update_client(struct i2c_client *client, u8 slice)
|
|
{
|
|
struct eeprom_data *data = i2c_get_clientdata(client);
|
|
int i, j;
|
|
|
|
mutex_lock(&data->update_lock);
|
|
|
|
if (!(data->valid & (1 << slice)) ||
|
|
time_after(jiffies, data->last_updated[slice] + 300 * HZ)) {
|
|
dev_dbg(&client->dev, "Starting eeprom update, slice %u\n", slice);
|
|
|
|
if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_READ_I2C_BLOCK)) {
|
|
for (i = slice << 5; i < (slice + 1) << 5; i += 32)
|
|
if (i2c_smbus_read_i2c_block_data(client, i,
|
|
32, data->data + i)
|
|
!= 32)
|
|
goto exit;
|
|
} else {
|
|
if (i2c_smbus_write_byte(client, slice << 5)) {
|
|
dev_dbg(&client->dev, "eeprom read start has failed!\n");
|
|
goto exit;
|
|
}
|
|
for (i = slice << 5; i < (slice + 1) << 5; i++) {
|
|
j = i2c_smbus_read_byte(client);
|
|
if (j < 0)
|
|
goto exit;
|
|
data->data[i] = (u8) j;
|
|
}
|
|
}
|
|
data->last_updated[slice] = jiffies;
|
|
data->valid |= (1 << slice);
|
|
}
|
|
exit:
|
|
mutex_unlock(&data->update_lock);
|
|
}
|
|
|
|
static ssize_t eeprom_read(struct kobject *kobj, struct bin_attribute *bin_attr,
|
|
char *buf, loff_t off, size_t count)
|
|
{
|
|
struct i2c_client *client = to_i2c_client(container_of(kobj, struct device, kobj));
|
|
struct eeprom_data *data = i2c_get_clientdata(client);
|
|
u8 slice;
|
|
|
|
if (off > EEPROM_SIZE)
|
|
return 0;
|
|
if (off + count > EEPROM_SIZE)
|
|
count = EEPROM_SIZE - off;
|
|
|
|
/* Only refresh slices which contain requested bytes */
|
|
for (slice = off >> 5; slice <= (off + count - 1) >> 5; slice++)
|
|
eeprom_update_client(client, slice);
|
|
|
|
/* Hide Vaio private settings to regular users:
|
|
- BIOS passwords: bytes 0x00 to 0x0f
|
|
- UUID: bytes 0x10 to 0x1f
|
|
- Serial number: 0xc0 to 0xdf */
|
|
if (data->nature == VAIO && !capable(CAP_SYS_ADMIN)) {
|
|
int i;
|
|
|
|
for (i = 0; i < count; i++) {
|
|
if ((off + i <= 0x1f) ||
|
|
(off + i >= 0xc0 && off + i <= 0xdf))
|
|
buf[i] = 0;
|
|
else
|
|
buf[i] = data->data[off + i];
|
|
}
|
|
} else {
|
|
memcpy(buf, &data->data[off], count);
|
|
}
|
|
|
|
return count;
|
|
}
|
|
|
|
static struct bin_attribute eeprom_attr = {
|
|
.attr = {
|
|
.name = "eeprom",
|
|
.mode = S_IRUGO,
|
|
},
|
|
.size = EEPROM_SIZE,
|
|
.read = eeprom_read,
|
|
};
|
|
|
|
static int eeprom_attach_adapter(struct i2c_adapter *adapter)
|
|
{
|
|
return i2c_probe(adapter, &addr_data, eeprom_detect);
|
|
}
|
|
|
|
/* This function is called by i2c_probe */
|
|
static int eeprom_detect(struct i2c_adapter *adapter, int address, int kind)
|
|
{
|
|
struct i2c_client *new_client;
|
|
struct eeprom_data *data;
|
|
int err = 0;
|
|
|
|
/* There are three ways we can read the EEPROM data:
|
|
(1) I2C block reads (faster, but unsupported by most adapters)
|
|
(2) Consecutive byte reads (100% overhead)
|
|
(3) Regular byte data reads (200% overhead)
|
|
The third method is not implemented by this driver because all
|
|
known adapters support at least the second. */
|
|
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_BYTE_DATA
|
|
| I2C_FUNC_SMBUS_BYTE))
|
|
goto exit;
|
|
|
|
if (!(data = kzalloc(sizeof(struct eeprom_data), GFP_KERNEL))) {
|
|
err = -ENOMEM;
|
|
goto exit;
|
|
}
|
|
|
|
new_client = &data->client;
|
|
memset(data->data, 0xff, EEPROM_SIZE);
|
|
i2c_set_clientdata(new_client, data);
|
|
new_client->addr = address;
|
|
new_client->adapter = adapter;
|
|
new_client->driver = &eeprom_driver;
|
|
new_client->flags = 0;
|
|
|
|
/* Fill in the remaining client fields */
|
|
strlcpy(new_client->name, "eeprom", I2C_NAME_SIZE);
|
|
data->valid = 0;
|
|
mutex_init(&data->update_lock);
|
|
data->nature = UNKNOWN;
|
|
|
|
/* Tell the I2C layer a new client has arrived */
|
|
if ((err = i2c_attach_client(new_client)))
|
|
goto exit_kfree;
|
|
|
|
/* Detect the Vaio nature of EEPROMs.
|
|
We use the "PCG-" or "VGN-" prefix as the signature. */
|
|
if (address == 0x57) {
|
|
char name[4];
|
|
|
|
name[0] = i2c_smbus_read_byte_data(new_client, 0x80);
|
|
name[1] = i2c_smbus_read_byte(new_client);
|
|
name[2] = i2c_smbus_read_byte(new_client);
|
|
name[3] = i2c_smbus_read_byte(new_client);
|
|
|
|
if (!memcmp(name, "PCG-", 4) || !memcmp(name, "VGN-", 4)) {
|
|
dev_info(&new_client->dev, "Vaio EEPROM detected, "
|
|
"enabling privacy protection\n");
|
|
data->nature = VAIO;
|
|
}
|
|
}
|
|
|
|
/* create the sysfs eeprom file */
|
|
err = sysfs_create_bin_file(&new_client->dev.kobj, &eeprom_attr);
|
|
if (err)
|
|
goto exit_detach;
|
|
|
|
return 0;
|
|
|
|
exit_detach:
|
|
i2c_detach_client(new_client);
|
|
exit_kfree:
|
|
kfree(data);
|
|
exit:
|
|
return err;
|
|
}
|
|
|
|
static int eeprom_detach_client(struct i2c_client *client)
|
|
{
|
|
int err;
|
|
|
|
sysfs_remove_bin_file(&client->dev.kobj, &eeprom_attr);
|
|
|
|
err = i2c_detach_client(client);
|
|
if (err)
|
|
return err;
|
|
|
|
kfree(i2c_get_clientdata(client));
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int __init eeprom_init(void)
|
|
{
|
|
return i2c_add_driver(&eeprom_driver);
|
|
}
|
|
|
|
static void __exit eeprom_exit(void)
|
|
{
|
|
i2c_del_driver(&eeprom_driver);
|
|
}
|
|
|
|
|
|
MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and "
|
|
"Philip Edelbrock <phil@netroedge.com> and "
|
|
"Greg Kroah-Hartman <greg@kroah.com>");
|
|
MODULE_DESCRIPTION("I2C EEPROM driver");
|
|
MODULE_LICENSE("GPL");
|
|
|
|
module_init(eeprom_init);
|
|
module_exit(eeprom_exit);
|