drivers/hwmon/adt7410.c - linux - Git at Google

 /*
  * adt7410.c - Part of lm_sensors, Linux kernel modules for hardware
  *	 monitoring
  * This driver handles the ADT7410 and compatible digital temperature sensors.
  * Hartmut Knaack <knaack.h@gmx.de> 2012-07-22
  * based on lm75.c by Frodo Looijaard <frodol@dds.nl>
  * and adt7410.c from iio-staging by Sonic Zhang <sonic.zhang@analog.com>
  *
  * 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/delay.h>

 /*
  * ADT7410 registers definition
  */

 #define ADT7410_TEMPERATURE		0
 #define ADT7410_STATUS			2
 #define ADT7410_CONFIG			3
 #define ADT7410_T_ALARM_HIGH		4
 #define ADT7410_T_ALARM_LOW		6
 #define ADT7410_T_CRIT			8
 #define ADT7410_T_HYST			0xA

 /*
  * ADT7410 status
  */
 #define ADT7410_STAT_T_LOW		(1 << 4)
 #define ADT7410_STAT_T_HIGH		(1 << 5)
 #define ADT7410_STAT_T_CRIT		(1 << 6)
 #define ADT7410_STAT_NOT_RDY		(1 << 7)

 /*
  * ADT7410 config
  */
 #define ADT7410_FAULT_QUEUE_MASK	(1 << 0 | 1 << 1)
 #define ADT7410_CT_POLARITY		(1 << 2)
 #define ADT7410_INT_POLARITY		(1 << 3)
 #define ADT7410_EVENT_MODE		(1 << 4)
 #define ADT7410_MODE_MASK		(1 << 5 | 1 << 6)
 #define ADT7410_FULL			(0 << 5 | 0 << 6)
 #define ADT7410_PD			(1 << 5 | 1 << 6)
 #define ADT7410_RESOLUTION		(1 << 7)

 /*
  * ADT7410 masks
  */
 #define ADT7410_T13_VALUE_MASK			0xFFF8
 #define ADT7410_T_HYST_MASK			0xF

 /* straight from the datasheet */
 #define ADT7410_TEMP_MIN (-55000)
 #define ADT7410_TEMP_MAX 150000

 enum adt7410_type {		/* keep sorted in alphabetical order */
 	adt7410,
 };

 /* Addresses scanned */
 static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b,
 					I2C_CLIENT_END };

 static const u8 ADT7410_REG_TEMP[4] = {
 	ADT7410_TEMPERATURE,		/* input */
 	ADT7410_T_ALARM_HIGH,		/* high */
 	ADT7410_T_ALARM_LOW,		/* low */
 	ADT7410_T_CRIT,			/* critical */
 };

 /* Each client has this additional data */
 struct adt7410_data {
 	struct device		*hwmon_dev;
 	struct mutex		update_lock;
 	u8			config;
 	u8			oldconfig;
 	bool			valid;		/* true if registers valid */
 	unsigned long		last_updated;	/* In jiffies */
 	s16			temp[4];	/* Register values,
 						   0 = input
 						   1 = high
 						   2 = low
 						   3 = critical */
 	u8			hyst;		/* hysteresis offset */
 };

 /*
  * adt7410 register access by I2C
  */
 static int adt7410_temp_ready(struct i2c_client *client)
 {
 	int i, status;

 	for (i = 0; i < 6; i++) {
 		status = i2c_smbus_read_byte_data(client, ADT7410_STATUS);
 		if (status < 0)
 			return status;
 		if (!(status & ADT7410_STAT_NOT_RDY))
 			return 0;
 		msleep(60);
 	}
 	return -ETIMEDOUT;
 }

 static struct adt7410_data *adt7410_update_device(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct adt7410_data *data = i2c_get_clientdata(client);
 	struct adt7410_data *ret = data;
 	mutex_lock(&data->update_lock);

 	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
 	    || !data->valid) {
 		int i, status;

 		dev_dbg(&client->dev, "Starting update\n");

 		status = adt7410_temp_ready(client); /* check for new value */
 		if (unlikely(status)) {
 			ret = ERR_PTR(status);
 			goto abort;
 		}
 		for (i = 0; i < ARRAY_SIZE(data->temp); i++) {
 			status = i2c_smbus_read_word_swapped(client,
 							ADT7410_REG_TEMP[i]);
 			if (unlikely(status < 0)) {
 				dev_dbg(dev,
 					"Failed to read value: reg %d, error %d\n",
 					ADT7410_REG_TEMP[i], status);
 				ret = ERR_PTR(status);
 				goto abort;
 			}
 			data->temp[i] = status;
 		}
 		status = i2c_smbus_read_byte_data(client, ADT7410_T_HYST);
 		if (unlikely(status < 0)) {
 			dev_dbg(dev,
 				"Failed to read value: reg %d, error %d\n",
 				ADT7410_T_HYST, status);
 			ret = ERR_PTR(status);
 			goto abort;
 		}
 		data->hyst = status;
 		data->last_updated = jiffies;
 		data->valid = true;
 	}

 abort:
 	mutex_unlock(&data->update_lock);
 	return ret;
 }

 static s16 ADT7410_TEMP_TO_REG(long temp)
 {
 	return DIV_ROUND_CLOSEST(clamp_val(temp, ADT7410_TEMP_MIN,
 					   ADT7410_TEMP_MAX) * 128, 1000);
 }

 static int ADT7410_REG_TO_TEMP(struct adt7410_data *data, s16 reg)
 {
 	/* in 13 bit mode, bits 0-2 are status flags - mask them out */
 	if (!(data->config & ADT7410_RESOLUTION))
 		reg &= ADT7410_T13_VALUE_MASK;
 	/*
 	 * temperature is stored in twos complement format, in steps of
 	 * 1/128°C
 	 */
 	return DIV_ROUND_CLOSEST(reg * 1000, 128);
 }

 /*-----------------------------------------------------------------------*/

 /* sysfs attributes for hwmon */

 static ssize_t adt7410_show_temp(struct device *dev,
 				 struct device_attribute *da, char *buf)
 {
 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 	struct adt7410_data *data = adt7410_update_device(dev);

 	if (IS_ERR(data))
 		return PTR_ERR(data);

 	return sprintf(buf, "%d\n", ADT7410_REG_TO_TEMP(data,
 		       data->temp[attr->index]));
 }

 static ssize_t adt7410_set_temp(struct device *dev,
 				struct device_attribute *da,
 				const char *buf, size_t count)
 {
 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 	struct i2c_client *client = to_i2c_client(dev);
 	struct adt7410_data *data = i2c_get_clientdata(client);
 	int nr = attr->index;
 	long temp;
 	int ret;

 	ret = kstrtol(buf, 10, &temp);
 	if (ret)
 		return ret;

 	mutex_lock(&data->update_lock);
 	data->temp[nr] = ADT7410_TEMP_TO_REG(temp);
 	ret = i2c_smbus_write_word_swapped(client, ADT7410_REG_TEMP[nr],
 					   data->temp[nr]);
 	if (ret)
 		count = ret;
 	mutex_unlock(&data->update_lock);
 	return count;
 }

 static ssize_t adt7410_show_t_hyst(struct device *dev,
 				   struct device_attribute *da,
 				   char *buf)
 {
 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 	struct adt7410_data *data;
 	int nr = attr->index;
 	int hyst;

 	data = adt7410_update_device(dev);
 	if (IS_ERR(data))
 		return PTR_ERR(data);
 	hyst = (data->hyst & ADT7410_T_HYST_MASK) * 1000;

 	/*
 	 * hysteresis is stored as a 4 bit offset in the device, convert it
 	 * to an absolute value
 	 */
 	if (nr == 2)	/* min has positive offset, others have negative */
 		hyst = -hyst;
 	return sprintf(buf, "%d\n",
 		       ADT7410_REG_TO_TEMP(data, data->temp[nr]) - hyst);
 }

 static ssize_t adt7410_set_t_hyst(struct device *dev,
 				  struct device_attribute *da,
 				  const char *buf, size_t count)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct adt7410_data *data = i2c_get_clientdata(client);
 	int limit, ret;
 	long hyst;

 	ret = kstrtol(buf, 10, &hyst);
 	if (ret)
 		return ret;
 	/* convert absolute hysteresis value to a 4 bit delta value */
 	limit = ADT7410_REG_TO_TEMP(data, data->temp[1]);
 	hyst = clamp_val(hyst, ADT7410_TEMP_MIN, ADT7410_TEMP_MAX);
 	data->hyst = clamp_val(DIV_ROUND_CLOSEST(limit - hyst, 1000), 0,
 			       ADT7410_T_HYST_MASK);
 	ret = i2c_smbus_write_byte_data(client, ADT7410_T_HYST, data->hyst);
 	if (ret)
 		return ret;

 	return count;
 }

 static ssize_t adt7410_show_alarm(struct device *dev,
 				  struct device_attribute *da,
 				  char *buf)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 	int ret;

 	ret = i2c_smbus_read_byte_data(client, ADT7410_STATUS);
 	if (ret < 0)
 		return ret;

 	return sprintf(buf, "%d\n", !!(ret & attr->index));
 }

 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, adt7410_show_temp, NULL, 0);
 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
 			  adt7410_show_temp, adt7410_set_temp, 1);
 static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO,
 			  adt7410_show_temp, adt7410_set_temp, 2);
 static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO,
 			  adt7410_show_temp, adt7410_set_temp, 3);
 static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO,
 			  adt7410_show_t_hyst, adt7410_set_t_hyst, 1);
 static SENSOR_DEVICE_ATTR(temp1_min_hyst, S_IRUGO,
 			  adt7410_show_t_hyst, NULL, 2);
 static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IRUGO,
 			  adt7410_show_t_hyst, NULL, 3);
 static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, adt7410_show_alarm,
 			  NULL, ADT7410_STAT_T_LOW);
 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, adt7410_show_alarm,
 			  NULL, ADT7410_STAT_T_HIGH);
 static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, adt7410_show_alarm,
 			  NULL, ADT7410_STAT_T_CRIT);

 static struct attribute *adt7410_attributes[] = {
 	&sensor_dev_attr_temp1_input.dev_attr.attr,
 	&sensor_dev_attr_temp1_max.dev_attr.attr,
 	&sensor_dev_attr_temp1_min.dev_attr.attr,
 	&sensor_dev_attr_temp1_crit.dev_attr.attr,
 	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
 	&sensor_dev_attr_temp1_min_hyst.dev_attr.attr,
 	&sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
 	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
 	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
 	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
 	NULL
 };

 static const struct attribute_group adt7410_group = {
 	.attrs = adt7410_attributes,
 };

 /*-----------------------------------------------------------------------*/

 /* device probe and removal */

 static int adt7410_probe(struct i2c_client *client,
 			 const struct i2c_device_id *id)
 {
 	struct adt7410_data *data;
 	int ret;

 	if (!i2c_check_functionality(client->adapter,
 			I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA))
 		return -ENODEV;

 	data = devm_kzalloc(&client->dev, sizeof(struct adt7410_data),
 			    GFP_KERNEL);
 	if (!data)
 		return -ENOMEM;

 	i2c_set_clientdata(client, data);
 	mutex_init(&data->update_lock);

 	/* configure as specified */
 	ret = i2c_smbus_read_byte_data(client, ADT7410_CONFIG);
 	if (ret < 0) {
 		dev_dbg(&client->dev, "Can't read config? %d\n", ret);
 		return ret;
 	}
 	data->oldconfig = ret;
 	/*
 	 * Set to 16 bit resolution, continous conversion and comparator mode.
 	 */
 	data->config = ret | ADT7410_FULL | ADT7410_RESOLUTION |
 			ADT7410_EVENT_MODE;
 	if (data->config != data->oldconfig) {
 		ret = i2c_smbus_write_byte_data(client, ADT7410_CONFIG,
 						data->config);
 		if (ret)
 			return ret;
 	}
 	dev_dbg(&client->dev, "Config %02x\n", data->config);

 	/* Register sysfs hooks */
 	ret = sysfs_create_group(&client->dev.kobj, &adt7410_group);
 	if (ret)
 		goto exit_restore;

 	data->hwmon_dev = hwmon_device_register(&client->dev);
 	if (IS_ERR(data->hwmon_dev)) {
 		ret = PTR_ERR(data->hwmon_dev);
 		goto exit_remove;
 	}

 	dev_info(&client->dev, "sensor '%s'\n", client->name);

 	return 0;

 exit_remove:
 	sysfs_remove_group(&client->dev.kobj, &adt7410_group);
 exit_restore:
 	i2c_smbus_write_byte_data(client, ADT7410_CONFIG, data->oldconfig);
 	return ret;
 }

 static int adt7410_remove(struct i2c_client *client)
 {
 	struct adt7410_data *data = i2c_get_clientdata(client);

 	hwmon_device_unregister(data->hwmon_dev);
 	sysfs_remove_group(&client->dev.kobj, &adt7410_group);
 	if (data->oldconfig != data->config)
 		i2c_smbus_write_byte_data(client, ADT7410_CONFIG,
 					  data->oldconfig);
 	return 0;
 }

 static const struct i2c_device_id adt7410_ids[] = {
 	{ "adt7410", adt7410, },
 	{ /* LIST END */ }
 };
 MODULE_DEVICE_TABLE(i2c, adt7410_ids);

 #ifdef CONFIG_PM
 static int adt7410_suspend(struct device *dev)
 {
 	int ret;
 	struct i2c_client *client = to_i2c_client(dev);
 	struct adt7410_data *data = i2c_get_clientdata(client);

 	ret = i2c_smbus_write_byte_data(client, ADT7410_CONFIG,
 					data->config | ADT7410_PD);
 	return ret;
 }

 static int adt7410_resume(struct device *dev)
 {
 	int ret;
 	struct i2c_client *client = to_i2c_client(dev);
 	struct adt7410_data *data = i2c_get_clientdata(client);

 	ret = i2c_smbus_write_byte_data(client, ADT7410_CONFIG, data->config);
 	return ret;
 }

 static const struct dev_pm_ops adt7410_dev_pm_ops = {
 	.suspend	= adt7410_suspend,
 	.resume		= adt7410_resume,
 };
 #define ADT7410_DEV_PM_OPS (&adt7410_dev_pm_ops)
 #else
 #define ADT7410_DEV_PM_OPS NULL
 #endif /* CONFIG_PM */

 static struct i2c_driver adt7410_driver = {
 	.class		= I2C_CLASS_HWMON,
 	.driver = {
 		.name	= "adt7410",
 		.pm	= ADT7410_DEV_PM_OPS,
 	},
 	.probe		= adt7410_probe,
 	.remove		= adt7410_remove,
 	.id_table	= adt7410_ids,
 	.address_list	= normal_i2c,
 };

 module_i2c_driver(adt7410_driver);

 MODULE_AUTHOR("Hartmut Knaack");
 MODULE_DESCRIPTION("ADT7410 driver");
 MODULE_LICENSE("GPL");
	/*
	* adt7410.c - Part of lm_sensors, Linux kernel modules for hardware
	* monitoring
	* This driver handles the ADT7410 and compatible digital temperature sensors.
	* Hartmut Knaack <knaack.h@gmx.de> 2012-07-22
	* based on lm75.c by Frodo Looijaard <frodol@dds.nl>
	* and adt7410.c from iio-staging by Sonic Zhang <sonic.zhang@analog.com>
	*
	* 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/delay.h>

	/*
	* ADT7410 registers definition
	*/

	#define ADT7410_TEMPERATURE 0
	#define ADT7410_STATUS 2
	#define ADT7410_CONFIG 3
	#define ADT7410_T_ALARM_HIGH 4
	#define ADT7410_T_ALARM_LOW 6
	#define ADT7410_T_CRIT 8
	#define ADT7410_T_HYST 0xA

	/*
	* ADT7410 status
	*/
	#define ADT7410_STAT_T_LOW (1 << 4)
	#define ADT7410_STAT_T_HIGH (1 << 5)
	#define ADT7410_STAT_T_CRIT (1 << 6)
	#define ADT7410_STAT_NOT_RDY (1 << 7)

	/*
	* ADT7410 config
	*/
	#define ADT7410_FAULT_QUEUE_MASK (1 << 0 \| 1 << 1)
	#define ADT7410_CT_POLARITY (1 << 2)
	#define ADT7410_INT_POLARITY (1 << 3)
	#define ADT7410_EVENT_MODE (1 << 4)
	#define ADT7410_MODE_MASK (1 << 5 \| 1 << 6)
	#define ADT7410_FULL (0 << 5 \| 0 << 6)
	#define ADT7410_PD (1 << 5 \| 1 << 6)
	#define ADT7410_RESOLUTION (1 << 7)

	/*
	* ADT7410 masks
	*/
	#define ADT7410_T13_VALUE_MASK 0xFFF8
	#define ADT7410_T_HYST_MASK 0xF

	/* straight from the datasheet */
	#define ADT7410_TEMP_MIN (-55000)
	#define ADT7410_TEMP_MAX 150000

	enum adt7410_type { /* keep sorted in alphabetical order */
	adt7410,
	};

	/* Addresses scanned */
	static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b,
	I2C_CLIENT_END };

	static const u8 ADT7410_REG_TEMP[4] = {
	ADT7410_TEMPERATURE, /* input */
	ADT7410_T_ALARM_HIGH, /* high */
	ADT7410_T_ALARM_LOW, /* low */
	ADT7410_T_CRIT, /* critical */
	};

	/* Each client has this additional data */
	struct adt7410_data {
	struct device *hwmon_dev;
	struct mutex update_lock;
	u8 config;
	u8 oldconfig;
	bool valid; /* true if registers valid */
	unsigned long last_updated; /* In jiffies */
	s16 temp[4]; /* Register values,
	0 = input
	1 = high
	2 = low
	3 = critical */
	u8 hyst; /* hysteresis offset */
	};

	/*
	* adt7410 register access by I2C
	*/
	static int adt7410_temp_ready(struct i2c_client *client)
	{
	int i, status;

	for (i = 0; i < 6; i++) {
	status = i2c_smbus_read_byte_data(client, ADT7410_STATUS);
	if (status < 0)
	return status;
	if (!(status & ADT7410_STAT_NOT_RDY))
	return 0;
	msleep(60);
	}
	return -ETIMEDOUT;
	}

	static struct adt7410_data adt7410_update_device(struct device dev)
	{
	struct i2c_client *client = to_i2c_client(dev);
	struct adt7410_data *data = i2c_get_clientdata(client);
	struct adt7410_data *ret = data;
	mutex_lock(&data->update_lock);

	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
	\|\| !data->valid) {
	int i, status;

	dev_dbg(&client->dev, "Starting update\n");

	status = adt7410_temp_ready(client); /* check for new value */
	if (unlikely(status)) {
	ret = ERR_PTR(status);
	goto abort;
	}
	for (i = 0; i < ARRAY_SIZE(data->temp); i++) {
	status = i2c_smbus_read_word_swapped(client,
	ADT7410_REG_TEMP[i]);
	if (unlikely(status < 0)) {
	dev_dbg(dev,
	"Failed to read value: reg %d, error %d\n",
	ADT7410_REG_TEMP[i], status);
	ret = ERR_PTR(status);
	goto abort;
	}
	data->temp[i] = status;
	}
	status = i2c_smbus_read_byte_data(client, ADT7410_T_HYST);
	if (unlikely(status < 0)) {
	dev_dbg(dev,
	"Failed to read value: reg %d, error %d\n",
	ADT7410_T_HYST, status);
	ret = ERR_PTR(status);
	goto abort;
	}
	data->hyst = status;
	data->last_updated = jiffies;
	data->valid = true;
	}

	abort:
	mutex_unlock(&data->update_lock);
	return ret;
	}

	static s16 ADT7410_TEMP_TO_REG(long temp)
	{
	return DIV_ROUND_CLOSEST(clamp_val(temp, ADT7410_TEMP_MIN,
	ADT7410_TEMP_MAX) * 128, 1000);
	}

	static int ADT7410_REG_TO_TEMP(struct adt7410_data *data, s16 reg)
	{
	/* in 13 bit mode, bits 0-2 are status flags - mask them out */
	if (!(data->config & ADT7410_RESOLUTION))
	reg &= ADT7410_T13_VALUE_MASK;
	/*
	* temperature is stored in twos complement format, in steps of
	* 1/128°C
	*/
	return DIV_ROUND_CLOSEST(reg * 1000, 128);
	}

	/-----------------------------------------------------------------------/

	/* sysfs attributes for hwmon */

	static ssize_t adt7410_show_temp(struct device *dev,
	struct device_attribute da, char buf)
	{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
	struct adt7410_data *data = adt7410_update_device(dev);

	if (IS_ERR(data))
	return PTR_ERR(data);

	return sprintf(buf, "%d\n", ADT7410_REG_TO_TEMP(data,
	data->temp[attr->index]));
	}

	static ssize_t adt7410_set_temp(struct device *dev,
	struct device_attribute *da,
	const char *buf, size_t count)
	{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
	struct i2c_client *client = to_i2c_client(dev);
	struct adt7410_data *data = i2c_get_clientdata(client);
	int nr = attr->index;
	long temp;
	int ret;

	ret = kstrtol(buf, 10, &temp);
	if (ret)
	return ret;

	mutex_lock(&data->update_lock);
	data->temp[nr] = ADT7410_TEMP_TO_REG(temp);
	ret = i2c_smbus_write_word_swapped(client, ADT7410_REG_TEMP[nr],
	data->temp[nr]);
	if (ret)
	count = ret;
	mutex_unlock(&data->update_lock);
	return count;
	}

	static ssize_t adt7410_show_t_hyst(struct device *dev,
	struct device_attribute *da,
	char *buf)
	{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
	struct adt7410_data *data;
	int nr = attr->index;
	int hyst;

	data = adt7410_update_device(dev);
	if (IS_ERR(data))
	return PTR_ERR(data);
	hyst = (data->hyst & ADT7410_T_HYST_MASK) * 1000;

	/*
	* hysteresis is stored as a 4 bit offset in the device, convert it
	* to an absolute value
	*/
	if (nr == 2) /* min has positive offset, others have negative */
	hyst = -hyst;
	return sprintf(buf, "%d\n",
	ADT7410_REG_TO_TEMP(data, data->temp[nr]) - hyst);
	}

	static ssize_t adt7410_set_t_hyst(struct device *dev,
	struct device_attribute *da,
	const char *buf, size_t count)
	{
	struct i2c_client *client = to_i2c_client(dev);
	struct adt7410_data *data = i2c_get_clientdata(client);
	int limit, ret;
	long hyst;

	ret = kstrtol(buf, 10, &hyst);
	if (ret)
	return ret;
	/* convert absolute hysteresis value to a 4 bit delta value */
	limit = ADT7410_REG_TO_TEMP(data, data->temp[1]);
	hyst = clamp_val(hyst, ADT7410_TEMP_MIN, ADT7410_TEMP_MAX);
	data->hyst = clamp_val(DIV_ROUND_CLOSEST(limit - hyst, 1000), 0,
	ADT7410_T_HYST_MASK);
	ret = i2c_smbus_write_byte_data(client, ADT7410_T_HYST, data->hyst);
	if (ret)
	return ret;

	return count;
	}

	static ssize_t adt7410_show_alarm(struct device *dev,
	struct device_attribute *da,
	char *buf)
	{
	struct i2c_client *client = to_i2c_client(dev);
	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
	int ret;

	ret = i2c_smbus_read_byte_data(client, ADT7410_STATUS);
	if (ret < 0)
	return ret;

	return sprintf(buf, "%d\n", !!(ret & attr->index));
	}

	static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, adt7410_show_temp, NULL, 0);
	static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR \| S_IRUGO,
	adt7410_show_temp, adt7410_set_temp, 1);
	static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR \| S_IRUGO,
	adt7410_show_temp, adt7410_set_temp, 2);
	static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR \| S_IRUGO,
	adt7410_show_temp, adt7410_set_temp, 3);
	static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR \| S_IRUGO,
	adt7410_show_t_hyst, adt7410_set_t_hyst, 1);
	static SENSOR_DEVICE_ATTR(temp1_min_hyst, S_IRUGO,
	adt7410_show_t_hyst, NULL, 2);
	static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IRUGO,
	adt7410_show_t_hyst, NULL, 3);
	static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, adt7410_show_alarm,
	NULL, ADT7410_STAT_T_LOW);
	static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, adt7410_show_alarm,
	NULL, ADT7410_STAT_T_HIGH);
	static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, adt7410_show_alarm,
	NULL, ADT7410_STAT_T_CRIT);

	static struct attribute *adt7410_attributes[] = {
	&sensor_dev_attr_temp1_input.dev_attr.attr,
	&sensor_dev_attr_temp1_max.dev_attr.attr,
	&sensor_dev_attr_temp1_min.dev_attr.attr,
	&sensor_dev_attr_temp1_crit.dev_attr.attr,
	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
	&sensor_dev_attr_temp1_min_hyst.dev_attr.attr,
	&sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
	NULL
	};

	static const struct attribute_group adt7410_group = {
	.attrs = adt7410_attributes,
	};

	/-----------------------------------------------------------------------/

	/* device probe and removal */

	static int adt7410_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	struct adt7410_data *data;
	int ret;

	if (!i2c_check_functionality(client->adapter,
	I2C_FUNC_SMBUS_BYTE_DATA \| I2C_FUNC_SMBUS_WORD_DATA))
	return -ENODEV;

	data = devm_kzalloc(&client->dev, sizeof(struct adt7410_data),
	GFP_KERNEL);
	if (!data)
	return -ENOMEM;

	i2c_set_clientdata(client, data);
	mutex_init(&data->update_lock);

	/* configure as specified */
	ret = i2c_smbus_read_byte_data(client, ADT7410_CONFIG);
	if (ret < 0) {
	dev_dbg(&client->dev, "Can't read config? %d\n", ret);
	return ret;
	}
	data->oldconfig = ret;
	/*
	* Set to 16 bit resolution, continous conversion and comparator mode.
	*/
	data->config = ret \| ADT7410_FULL \| ADT7410_RESOLUTION \|
	ADT7410_EVENT_MODE;
	if (data->config != data->oldconfig) {
	ret = i2c_smbus_write_byte_data(client, ADT7410_CONFIG,
	data->config);
	if (ret)
	return ret;
	}
	dev_dbg(&client->dev, "Config %02x\n", data->config);

	/* Register sysfs hooks */
	ret = sysfs_create_group(&client->dev.kobj, &adt7410_group);
	if (ret)
	goto exit_restore;

	data->hwmon_dev = hwmon_device_register(&client->dev);
	if (IS_ERR(data->hwmon_dev)) {
	ret = PTR_ERR(data->hwmon_dev);
	goto exit_remove;
	}

	dev_info(&client->dev, "sensor '%s'\n", client->name);

	return 0;

	exit_remove:
	sysfs_remove_group(&client->dev.kobj, &adt7410_group);
	exit_restore:
	i2c_smbus_write_byte_data(client, ADT7410_CONFIG, data->oldconfig);
	return ret;
	}

	static int adt7410_remove(struct i2c_client *client)
	{
	struct adt7410_data *data = i2c_get_clientdata(client);

	hwmon_device_unregister(data->hwmon_dev);
	sysfs_remove_group(&client->dev.kobj, &adt7410_group);
	if (data->oldconfig != data->config)
	i2c_smbus_write_byte_data(client, ADT7410_CONFIG,
	data->oldconfig);
	return 0;
	}

	static const struct i2c_device_id adt7410_ids[] = {
	{ "adt7410", adt7410, },
	{ /* LIST END */ }
	};
	MODULE_DEVICE_TABLE(i2c, adt7410_ids);

	#ifdef CONFIG_PM
	static int adt7410_suspend(struct device *dev)
	{
	int ret;
	struct i2c_client *client = to_i2c_client(dev);
	struct adt7410_data *data = i2c_get_clientdata(client);

	ret = i2c_smbus_write_byte_data(client, ADT7410_CONFIG,
	data->config \| ADT7410_PD);
	return ret;
	}

	static int adt7410_resume(struct device *dev)
	{
	int ret;
	struct i2c_client *client = to_i2c_client(dev);
	struct adt7410_data *data = i2c_get_clientdata(client);

	ret = i2c_smbus_write_byte_data(client, ADT7410_CONFIG, data->config);
	return ret;
	}

	static const struct dev_pm_ops adt7410_dev_pm_ops = {
	.suspend = adt7410_suspend,
	.resume = adt7410_resume,
	};
	#define ADT7410_DEV_PM_OPS (&adt7410_dev_pm_ops)
	#else
	#define ADT7410_DEV_PM_OPS NULL
	#endif /* CONFIG_PM */

	static struct i2c_driver adt7410_driver = {
	.class = I2C_CLASS_HWMON,
	.driver = {
	.name = "adt7410",
	.pm = ADT7410_DEV_PM_OPS,
	},
	.probe = adt7410_probe,
	.remove = adt7410_remove,
	.id_table = adt7410_ids,
	.address_list = normal_i2c,
	};

	module_i2c_driver(adt7410_driver);

	MODULE_AUTHOR("Hartmut Knaack");
	MODULE_DESCRIPTION("ADT7410 driver");
	MODULE_LICENSE("GPL");