drivers/hwmon/lm95241.c - kernel/msm-4.9 - Gitiles

 /*
  * 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 TempFromReg(u8 val_h, u8 val_l)
 {
 	if (val_h & 0x80)
 		return val_h - 0x100;
 	return val_h * 1000 + val_l * 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);

 	return snprintf(buf, PAGE_SIZE - 1, "%d\n",
 		TempFromReg(data->temp[to_sensor_dev_attr(attr)->index],
 			    data->temp[to_sensor_dev_attr(attr)->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);
	/*
	* 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 TempFromReg(u8 val_h, u8 val_l)
	{
	if (val_h & 0x80)
	return val_h - 0x100;
	return val_h * 1000 + val_l * 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);

	return snprintf(buf, PAGE_SIZE - 1, "%d\n",
	TempFromReg(data->temp[to_sensor_dev_attr(attr)->index],
	data->temp[to_sensor_dev_attr(attr)->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);