- 根目录:
- drivers
- hwmon
- lm95241.c
/*
* Copyright (C) 2008, 2010 Davide Rizzo <elpa.rizzo@gmail.com>
*
* The LM95241 is a sensor chip made by National Semiconductors.
* It reports up to three temperatures (its own plus up to two external ones).
* Complete datasheet can be obtained from National's website at:
* http://www.national.com/ds.cgi/LM/LM95241.pdf
*
* 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/hwmon-sysfs.h>
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/sysfs.h>
#define DEVNAME "lm95241"
static const unsigned short normal_i2c[] = {
0x19, 0x2a, 0x2b, I2C_CLIENT_END };
/* LM95241 registers */
#define LM95241_REG_R_MAN_ID 0xFE
#define LM95241_REG_R_CHIP_ID 0xFF
#define LM95241_REG_R_STATUS 0x02
#define LM95241_REG_RW_CONFIG 0x03
#define LM95241_REG_RW_REM_FILTER 0x06
#define LM95241_REG_RW_TRUTHERM 0x07
#define LM95241_REG_W_ONE_SHOT 0x0F
#define LM95241_REG_R_LOCAL_TEMPH 0x10
#define LM95241_REG_R_REMOTE1_TEMPH 0x11
#define LM95241_REG_R_REMOTE2_TEMPH 0x12
#define LM95241_REG_R_LOCAL_TEMPL 0x20
#define LM95241_REG_R_REMOTE1_TEMPL 0x21
#define LM95241_REG_R_REMOTE2_TEMPL 0x22
#define LM95241_REG_RW_REMOTE_MODEL 0x30
/* LM95241 specific bitfields */
#define CFG_STOP 0x40
#define CFG_CR0076 0x00
#define CFG_CR0182 0x10
#define CFG_CR1000 0x20
#define CFG_CR2700 0x30
#define R1MS_SHIFT 0
#define R2MS_SHIFT 2
#define R1MS_MASK (0x01 << (R1MS_SHIFT))
#define R2MS_MASK (0x01 << (R2MS_SHIFT))
#define R1DF_SHIFT 1
#define R2DF_SHIFT 2
#define R1DF_MASK (0x01 << (R1DF_SHIFT))
#define R2DF_MASK (0x01 << (R2DF_SHIFT))
#define R1FE_MASK 0x01
#define R2FE_MASK 0x05
#define TT1_SHIFT 0
#define TT2_SHIFT 4
#define TT_OFF 0
#define TT_ON 1
#define TT_MASK 7
#define MANUFACTURER_ID 0x01
#define DEFAULT_REVISION 0xA4
static const u8 lm95241_reg_address[] = {
LM95241_REG_R_LOCAL_TEMPH,
LM95241_REG_R_LOCAL_TEMPL,
LM95241_REG_R_REMOTE1_TEMPH,
LM95241_REG_R_REMOTE1_TEMPL,
LM95241_REG_R_REMOTE2_TEMPH,
LM95241_REG_R_REMOTE2_TEMPL
};
/* Client data (each client gets its own) */
struct lm95241_data {
struct device *hwmon_dev;
struct mutex update_lock;
unsigned long last_updated, interval; /* in jiffies */
char valid; /* zero until following fields are valid */
/* registers values */
u8 temp[ARRAY_SIZE(lm95241_reg_address)];
u8 config, model, trutherm;
};
/* Conversions */
static int temp_from_reg_signed(u8 val_h, u8 val_l)
{
s16 val_hl = (val_h << 8) | val_l;
return val_hl * 1000 / 256;
}
static int temp_from_reg_unsigned(u8 val_h, u8 val_l)
{
u16 val_hl = (val_h << 8) | val_l;
return val_hl * 1000 / 256;
}
static struct lm95241_data *lm95241_update_device(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct lm95241_data *data = i2c_get_clientdata(client);
mutex_lock(&data->update_lock);
if (time_after(jiffies, data->last_updated + data->interval) ||
!data->valid) {
int i;
dev_dbg(&client->dev, "Updating lm95241 data.\n");
for (i = 0; i < ARRAY_SIZE(lm95241_reg_address); i++)
data->temp[i]
= i2c_smbus_read_byte_data(client,
lm95241_reg_address[i]);
data->last_updated = jiffies;
data->valid = 1;
}
mutex_unlock(&data->update_lock);
return data;
}
/* Sysfs stuff */
static ssize_t show_input(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct lm95241_data *data = lm95241_update_device(dev);
int index = to_sensor_dev_attr(attr)->index;
return snprintf(buf, PAGE_SIZE - 1, "%d\n",
index == 0 || (data->config & (1 << (index / 2))) ?
temp_from_reg_signed(data->temp[index], data->temp[index + 1]) :
temp_from_reg_unsigned(data->temp[index],
data->temp[index + 1]));
}
static ssize_t show_type(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct i2c_client *client = to_i2c_client(dev);
struct lm95241_data *data = i2c_get_clientdata(client);
return snprintf(buf, PAGE_SIZE - 1,
data->model & to_sensor_dev_attr(attr)->index ? "1\n" : "2\n");
}
static ssize_t set_type(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct i2c_client *client = to_i2c_client(dev);
struct lm95241_data *data = i2c_get_clientdata(client);
unsigned long val;
int shift;
u8 mask = to_sensor_dev_attr(attr)->index;
if (strict_strtoul(buf, 10, &val) < 0)
return -EINVAL;
if (val != 1 && val != 2)
return -EINVAL;
shift = mask == R1MS_MASK ? TT1_SHIFT : TT2_SHIFT;
mutex_lock(&data->update_lock);
data->trutherm &= ~(TT_MASK << shift);
if (val == 1) {
data->model |= mask;
data->trutherm |= (TT_ON << shift);
} else {
data->model &= ~mask;
data->trutherm |= (TT_OFF << shift);
}
data->valid = 0;
i2c_smbus_write_byte_data(client, LM95241_REG_RW_REMOTE_MODEL,
data->model);
i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM,
data->trutherm);
mutex_unlock(&data->update_lock);
return count;
}
static ssize_t show_min(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct i2c_client *client = to_i2c_client(dev);
struct lm95241_data *data = i2c_get_clientdata(client);
return snprintf(buf, PAGE_SIZE - 1,
data->config & to_sensor_dev_attr(attr)->index ?
"-127000\n" : "0\n");
}
static ssize_t set_min(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct i2c_client *client = to_i2c_client(dev);
struct lm95241_data *data = i2c_get_clientdata(client);
long val;
if (strict_strtol(buf, 10, &val) < 0)
return -EINVAL;
if (val < -128000)
return -EINVAL;
mutex_lock(&data->update_lock);
if (val < 0)
data->config |= to_sensor_dev_attr(attr)->index;
else
data->config &= ~to_sensor_dev_attr(attr)->index;
data->valid = 0;
i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, data->config);
mutex_unlock(&data->update_lock);
return count;
}
static ssize_t show_max(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct i2c_client *client = to_i2c_client(dev);
struct lm95241_data *data = i2c_get_clientdata(client);
return snprintf(buf, PAGE_SIZE - 1,
data->config & to_sensor_dev_attr(attr)->index ?
"127000\n" : "255000\n");
}
static ssize_t set_max(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct i2c_client *client = to_i2c_client(dev);
struct lm95241_data *data = i2c_get_clientdata(client);
long val;
if (strict_strtol(buf, 10, &val) < 0)
return -EINVAL;
if (val >= 256000)
return -EINVAL;
mutex_lock(&data->update_lock);
if (val <= 127000)
data->config |= to_sensor_dev_attr(attr)->index;
else
data->config &= ~to_sensor_dev_attr(attr)->index;
data->valid = 0;
i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, data->config);
mutex_unlock(&data->update_lock);
return count;
}
static ssize_t show_interval(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct lm95241_data *data = lm95241_update_device(dev);
return snprintf(buf, PAGE_SIZE - 1, "%lu\n", 1000 * data->interval
/ HZ);
}
static ssize_t set_interval(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct i2c_client *client = to_i2c_client(dev);
struct lm95241_data *data = i2c_get_clientdata(client);
unsigned long val;
if (strict_strtoul(buf, 10, &val) < 0)
return -EINVAL;
data->interval = val * HZ / 1000;
return count;
}
static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_input, NULL, 0);
static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_input, NULL, 2);
static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_input, NULL, 4);
static SENSOR_DEVICE_ATTR(temp2_type, S_IWUSR | S_IRUGO, show_type, set_type,
R1MS_MASK);
static SENSOR_DEVICE_ATTR(temp3_type, S_IWUSR | S_IRUGO, show_type, set_type,
R2MS_MASK);
static SENSOR_DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_min, set_min,
R1DF_MASK);
static SENSOR_DEVICE_ATTR(temp3_min, S_IWUSR | S_IRUGO, show_min, set_min,
R2DF_MASK);
static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_max, set_max,
R1DF_MASK);
static SENSOR_DEVICE_ATTR(temp3_max, S_IWUSR | S_IRUGO, show_max, set_max,
R2DF_MASK);
static DEVICE_ATTR(update_interval, S_IWUSR | S_IRUGO, show_interval,
set_interval);
static struct attribute *lm95241_attributes[] = {
&sensor_dev_attr_temp1_input.dev_attr.attr,
&sensor_dev_attr_temp2_input.dev_attr.attr,
&sensor_dev_attr_temp3_input.dev_attr.attr,
&sensor_dev_attr_temp2_type.dev_attr.attr,
&sensor_dev_attr_temp3_type.dev_attr.attr,
&sensor_dev_attr_temp2_min.dev_attr.attr,
&sensor_dev_attr_temp3_min.dev_attr.attr,
&sensor_dev_attr_temp2_max.dev_attr.attr,
&sensor_dev_attr_temp3_max.dev_attr.attr,
&dev_attr_update_interval.attr,
NULL
};
static const struct attribute_group lm95241_group = {
.attrs = lm95241_attributes,
};
/* Return 0 if detection is successful, -ENODEV otherwise */
static int lm95241_detect(struct i2c_client *new_client,
struct i2c_board_info *info)
{
struct i2c_adapter *adapter = new_client->adapter;
int address = new_client->addr;
const char *name;
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
return -ENODEV;
if ((i2c_smbus_read_byte_data(new_client, LM95241_REG_R_MAN_ID)
== MANUFACTURER_ID)
&& (i2c_smbus_read_byte_data(new_client, LM95241_REG_R_CHIP_ID)
== DEFAULT_REVISION)) {
name = DEVNAME;
} else {
dev_dbg(&adapter->dev, "LM95241 detection failed at 0x%02x\n",
address);
return -ENODEV;
}
/* Fill the i2c board info */
strlcpy(info->type, name, I2C_NAME_SIZE);
return 0;
}
static void lm95241_init_client(struct i2c_client *client)
{
struct lm95241_data *data = i2c_get_clientdata(client);
data->interval = HZ; /* 1 sec default */
data->valid = 0;
data->config = CFG_CR0076;
data->model = 0;
data->trutherm = (TT_OFF << TT1_SHIFT) | (TT_OFF << TT2_SHIFT);
i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, data->config);
i2c_smbus_write_byte_data(client, LM95241_REG_RW_REM_FILTER,
R1FE_MASK | R2FE_MASK);
i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM,
data->trutherm);
i2c_smbus_write_byte_data(client, LM95241_REG_RW_REMOTE_MODEL,
data->model);
}
static int lm95241_probe(struct i2c_client *new_client,
const struct i2c_device_id *id)
{
struct lm95241_data *data;
int err;
data = kzalloc(sizeof(struct lm95241_data), GFP_KERNEL);
if (!data) {
err = -ENOMEM;
goto exit;
}
i2c_set_clientdata(new_client, data);
mutex_init(&data->update_lock);
/* Initialize the LM95241 chip */
lm95241_init_client(new_client);
/* Register sysfs hooks */
err = sysfs_create_group(&new_client->dev.kobj, &lm95241_group);
if (err)
goto exit_free;
data->hwmon_dev = hwmon_device_register(&new_client->dev);
if (IS_ERR(data->hwmon_dev)) {
err = PTR_ERR(data->hwmon_dev);
goto exit_remove_files;
}
return 0;
exit_remove_files:
sysfs_remove_group(&new_client->dev.kobj, &lm95241_group);
exit_free:
kfree(data);
exit:
return err;
}
static int lm95241_remove(struct i2c_client *client)
{
struct lm95241_data *data = i2c_get_clientdata(client);
hwmon_device_unregister(data->hwmon_dev);
sysfs_remove_group(&client->dev.kobj, &lm95241_group);
kfree(data);
return 0;
}
/* Driver data (common to all clients) */
static const struct i2c_device_id lm95241_id[] = {
{ DEVNAME, 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, lm95241_id);
static struct i2c_driver lm95241_driver = {
.class = I2C_CLASS_HWMON,
.driver = {
.name = DEVNAME,
},
.probe = lm95241_probe,
.remove = lm95241_remove,
.id_table = lm95241_id,
.detect = lm95241_detect,
.address_list = normal_i2c,
};
static int __init sensors_lm95241_init(void)
{
return i2c_add_driver(&lm95241_driver);
}
static void __exit sensors_lm95241_exit(void)
{
i2c_del_driver(&lm95241_driver);
}
MODULE_AUTHOR("Davide Rizzo <elpa.rizzo@gmail.com>");
MODULE_DESCRIPTION("LM95241 sensor driver");
MODULE_LICENSE("GPL");
module_init(sensors_lm95241_init);
module_exit(sensors_lm95241_exit);