302 строки
9.0 KiB
C
302 строки
9.0 KiB
C
/*
|
|
lm75.c - Part of lm_sensors, Linux kernel modules for hardware
|
|
monitoring
|
|
Copyright (c) 1998, 1999 Frodo Looijaard <frodol@dds.nl>
|
|
|
|
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/module.h>
|
|
#include <linux/init.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/jiffies.h>
|
|
#include <linux/i2c.h>
|
|
#include <linux/hwmon.h>
|
|
#include <linux/err.h>
|
|
#include <linux/mutex.h>
|
|
#include "lm75.h"
|
|
|
|
|
|
/* Addresses to scan */
|
|
static unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
|
|
0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
|
|
|
|
/* Insmod parameters */
|
|
I2C_CLIENT_INSMOD_1(lm75);
|
|
|
|
/* Many LM75 constants specified below */
|
|
|
|
/* The LM75 registers */
|
|
#define LM75_REG_TEMP 0x00
|
|
#define LM75_REG_CONF 0x01
|
|
#define LM75_REG_TEMP_HYST 0x02
|
|
#define LM75_REG_TEMP_OS 0x03
|
|
|
|
/* Each client has this additional data */
|
|
struct lm75_data {
|
|
struct i2c_client client;
|
|
struct class_device *class_dev;
|
|
struct mutex update_lock;
|
|
char valid; /* !=0 if following fields are valid */
|
|
unsigned long last_updated; /* In jiffies */
|
|
u16 temp_input; /* Register values */
|
|
u16 temp_max;
|
|
u16 temp_hyst;
|
|
};
|
|
|
|
static int lm75_attach_adapter(struct i2c_adapter *adapter);
|
|
static int lm75_detect(struct i2c_adapter *adapter, int address, int kind);
|
|
static void lm75_init_client(struct i2c_client *client);
|
|
static int lm75_detach_client(struct i2c_client *client);
|
|
static int lm75_read_value(struct i2c_client *client, u8 reg);
|
|
static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value);
|
|
static struct lm75_data *lm75_update_device(struct device *dev);
|
|
|
|
|
|
/* This is the driver that will be inserted */
|
|
static struct i2c_driver lm75_driver = {
|
|
.driver = {
|
|
.name = "lm75",
|
|
},
|
|
.id = I2C_DRIVERID_LM75,
|
|
.attach_adapter = lm75_attach_adapter,
|
|
.detach_client = lm75_detach_client,
|
|
};
|
|
|
|
#define show(value) \
|
|
static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf) \
|
|
{ \
|
|
struct lm75_data *data = lm75_update_device(dev); \
|
|
return sprintf(buf, "%d\n", LM75_TEMP_FROM_REG(data->value)); \
|
|
}
|
|
show(temp_max);
|
|
show(temp_hyst);
|
|
show(temp_input);
|
|
|
|
#define set(value, reg) \
|
|
static ssize_t set_##value(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) \
|
|
{ \
|
|
struct i2c_client *client = to_i2c_client(dev); \
|
|
struct lm75_data *data = i2c_get_clientdata(client); \
|
|
int temp = simple_strtoul(buf, NULL, 10); \
|
|
\
|
|
mutex_lock(&data->update_lock); \
|
|
data->value = LM75_TEMP_TO_REG(temp); \
|
|
lm75_write_value(client, reg, data->value); \
|
|
mutex_unlock(&data->update_lock); \
|
|
return count; \
|
|
}
|
|
set(temp_max, LM75_REG_TEMP_OS);
|
|
set(temp_hyst, LM75_REG_TEMP_HYST);
|
|
|
|
static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp_max, set_temp_max);
|
|
static DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO, show_temp_hyst, set_temp_hyst);
|
|
static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_input, NULL);
|
|
|
|
static int lm75_attach_adapter(struct i2c_adapter *adapter)
|
|
{
|
|
if (!(adapter->class & I2C_CLASS_HWMON))
|
|
return 0;
|
|
return i2c_probe(adapter, &addr_data, lm75_detect);
|
|
}
|
|
|
|
/* This function is called by i2c_probe */
|
|
static int lm75_detect(struct i2c_adapter *adapter, int address, int kind)
|
|
{
|
|
int i;
|
|
struct i2c_client *new_client;
|
|
struct lm75_data *data;
|
|
int err = 0;
|
|
const char *name = "";
|
|
|
|
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
|
|
I2C_FUNC_SMBUS_WORD_DATA))
|
|
goto exit;
|
|
|
|
/* OK. For now, we presume we have a valid client. We now create the
|
|
client structure, even though we cannot fill it completely yet.
|
|
But it allows us to access lm75_{read,write}_value. */
|
|
if (!(data = kzalloc(sizeof(struct lm75_data), GFP_KERNEL))) {
|
|
err = -ENOMEM;
|
|
goto exit;
|
|
}
|
|
|
|
new_client = &data->client;
|
|
i2c_set_clientdata(new_client, data);
|
|
new_client->addr = address;
|
|
new_client->adapter = adapter;
|
|
new_client->driver = &lm75_driver;
|
|
new_client->flags = 0;
|
|
|
|
/* Now, we do the remaining detection. There is no identification-
|
|
dedicated register so we have to rely on several tricks:
|
|
unused bits, registers cycling over 8-address boundaries,
|
|
addresses 0x04-0x07 returning the last read value.
|
|
The cycling+unused addresses combination is not tested,
|
|
since it would significantly slow the detection down and would
|
|
hardly add any value. */
|
|
if (kind < 0) {
|
|
int cur, conf, hyst, os;
|
|
|
|
/* Unused addresses */
|
|
cur = i2c_smbus_read_word_data(new_client, 0);
|
|
conf = i2c_smbus_read_byte_data(new_client, 1);
|
|
hyst = i2c_smbus_read_word_data(new_client, 2);
|
|
if (i2c_smbus_read_word_data(new_client, 4) != hyst
|
|
|| i2c_smbus_read_word_data(new_client, 5) != hyst
|
|
|| i2c_smbus_read_word_data(new_client, 6) != hyst
|
|
|| i2c_smbus_read_word_data(new_client, 7) != hyst)
|
|
goto exit_free;
|
|
os = i2c_smbus_read_word_data(new_client, 3);
|
|
if (i2c_smbus_read_word_data(new_client, 4) != os
|
|
|| i2c_smbus_read_word_data(new_client, 5) != os
|
|
|| i2c_smbus_read_word_data(new_client, 6) != os
|
|
|| i2c_smbus_read_word_data(new_client, 7) != os)
|
|
goto exit_free;
|
|
|
|
/* Unused bits */
|
|
if (conf & 0xe0)
|
|
goto exit_free;
|
|
|
|
/* Addresses cycling */
|
|
for (i = 8; i < 0xff; i += 8)
|
|
if (i2c_smbus_read_byte_data(new_client, i + 1) != conf
|
|
|| i2c_smbus_read_word_data(new_client, i + 2) != hyst
|
|
|| i2c_smbus_read_word_data(new_client, i + 3) != os)
|
|
goto exit_free;
|
|
}
|
|
|
|
/* Determine the chip type - only one kind supported! */
|
|
if (kind <= 0)
|
|
kind = lm75;
|
|
|
|
if (kind == lm75) {
|
|
name = "lm75";
|
|
}
|
|
|
|
/* Fill in the remaining client fields and put it into the global list */
|
|
strlcpy(new_client->name, name, I2C_NAME_SIZE);
|
|
data->valid = 0;
|
|
mutex_init(&data->update_lock);
|
|
|
|
/* Tell the I2C layer a new client has arrived */
|
|
if ((err = i2c_attach_client(new_client)))
|
|
goto exit_free;
|
|
|
|
/* Initialize the LM75 chip */
|
|
lm75_init_client(new_client);
|
|
|
|
/* Register sysfs hooks */
|
|
data->class_dev = hwmon_device_register(&new_client->dev);
|
|
if (IS_ERR(data->class_dev)) {
|
|
err = PTR_ERR(data->class_dev);
|
|
goto exit_detach;
|
|
}
|
|
|
|
device_create_file(&new_client->dev, &dev_attr_temp1_max);
|
|
device_create_file(&new_client->dev, &dev_attr_temp1_max_hyst);
|
|
device_create_file(&new_client->dev, &dev_attr_temp1_input);
|
|
|
|
return 0;
|
|
|
|
exit_detach:
|
|
i2c_detach_client(new_client);
|
|
exit_free:
|
|
kfree(data);
|
|
exit:
|
|
return err;
|
|
}
|
|
|
|
static int lm75_detach_client(struct i2c_client *client)
|
|
{
|
|
struct lm75_data *data = i2c_get_clientdata(client);
|
|
hwmon_device_unregister(data->class_dev);
|
|
i2c_detach_client(client);
|
|
kfree(data);
|
|
return 0;
|
|
}
|
|
|
|
/* All registers are word-sized, except for the configuration register.
|
|
LM75 uses a high-byte first convention, which is exactly opposite to
|
|
the usual practice. */
|
|
static int lm75_read_value(struct i2c_client *client, u8 reg)
|
|
{
|
|
if (reg == LM75_REG_CONF)
|
|
return i2c_smbus_read_byte_data(client, reg);
|
|
else
|
|
return swab16(i2c_smbus_read_word_data(client, reg));
|
|
}
|
|
|
|
/* All registers are word-sized, except for the configuration register.
|
|
LM75 uses a high-byte first convention, which is exactly opposite to
|
|
the usual practice. */
|
|
static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value)
|
|
{
|
|
if (reg == LM75_REG_CONF)
|
|
return i2c_smbus_write_byte_data(client, reg, value);
|
|
else
|
|
return i2c_smbus_write_word_data(client, reg, swab16(value));
|
|
}
|
|
|
|
static void lm75_init_client(struct i2c_client *client)
|
|
{
|
|
int reg;
|
|
|
|
/* Enable if in shutdown mode */
|
|
reg = lm75_read_value(client, LM75_REG_CONF);
|
|
if (reg >= 0 && (reg & 0x01))
|
|
lm75_write_value(client, LM75_REG_CONF, reg & 0xfe);
|
|
}
|
|
|
|
static struct lm75_data *lm75_update_device(struct device *dev)
|
|
{
|
|
struct i2c_client *client = to_i2c_client(dev);
|
|
struct lm75_data *data = i2c_get_clientdata(client);
|
|
|
|
mutex_lock(&data->update_lock);
|
|
|
|
if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
|
|
|| !data->valid) {
|
|
dev_dbg(&client->dev, "Starting lm75 update\n");
|
|
|
|
data->temp_input = lm75_read_value(client, LM75_REG_TEMP);
|
|
data->temp_max = lm75_read_value(client, LM75_REG_TEMP_OS);
|
|
data->temp_hyst = lm75_read_value(client, LM75_REG_TEMP_HYST);
|
|
data->last_updated = jiffies;
|
|
data->valid = 1;
|
|
}
|
|
|
|
mutex_unlock(&data->update_lock);
|
|
|
|
return data;
|
|
}
|
|
|
|
static int __init sensors_lm75_init(void)
|
|
{
|
|
return i2c_add_driver(&lm75_driver);
|
|
}
|
|
|
|
static void __exit sensors_lm75_exit(void)
|
|
{
|
|
i2c_del_driver(&lm75_driver);
|
|
}
|
|
|
|
MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>");
|
|
MODULE_DESCRIPTION("LM75 driver");
|
|
MODULE_LICENSE("GPL");
|
|
|
|
module_init(sensors_lm75_init);
|
|
module_exit(sensors_lm75_exit);
|