drivers/hwmon/adt7x10.c - linux - Git at Google

 /*
  * adt7x10.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/hwmon.h>
 #include <linux/hwmon-sysfs.h>
 #include <linux/err.h>
 #include <linux/mutex.h>
 #include <linux/delay.h>
 #include <linux/interrupt.h>

 #include "adt7x10.h"

 /*
  * ADT7X10 status
  */
 #define ADT7X10_STAT_T_LOW		(1 << 4)
 #define ADT7X10_STAT_T_HIGH		(1 << 5)
 #define ADT7X10_STAT_T_CRIT		(1 << 6)
 #define ADT7X10_STAT_NOT_RDY		(1 << 7)

 /*
  * ADT7X10 config
  */
 #define ADT7X10_FAULT_QUEUE_MASK	(1 << 0 | 1 << 1)
 #define ADT7X10_CT_POLARITY		(1 << 2)
 #define ADT7X10_INT_POLARITY		(1 << 3)
 #define ADT7X10_EVENT_MODE		(1 << 4)
 #define ADT7X10_MODE_MASK		(1 << 5 | 1 << 6)
 #define ADT7X10_FULL			(0 << 5 | 0 << 6)
 #define ADT7X10_PD			(1 << 5 | 1 << 6)
 #define ADT7X10_RESOLUTION		(1 << 7)

 /*
  * ADT7X10 masks
  */
 #define ADT7X10_T13_VALUE_MASK		0xFFF8
 #define ADT7X10_T_HYST_MASK		0xF

 /* straight from the datasheet */
 #define ADT7X10_TEMP_MIN (-55000)
 #define ADT7X10_TEMP_MAX 150000

 /* Each client has this additional data */
 struct adt7x10_data {
 	const struct adt7x10_ops *ops;
 	const char		*name;
 	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 */
 };

 static int adt7x10_read_byte(struct device *dev, u8 reg)
 {
 	struct adt7x10_data *d = dev_get_drvdata(dev);
 	return d->ops->read_byte(dev, reg);
 }

 static int adt7x10_write_byte(struct device *dev, u8 reg, u8 data)
 {
 	struct adt7x10_data *d = dev_get_drvdata(dev);
 	return d->ops->write_byte(dev, reg, data);
 }

 static int adt7x10_read_word(struct device *dev, u8 reg)
 {
 	struct adt7x10_data *d = dev_get_drvdata(dev);
 	return d->ops->read_word(dev, reg);
 }

 static int adt7x10_write_word(struct device *dev, u8 reg, u16 data)
 {
 	struct adt7x10_data *d = dev_get_drvdata(dev);
 	return d->ops->write_word(dev, reg, data);
 }

 static const u8 ADT7X10_REG_TEMP[4] = {
 	ADT7X10_TEMPERATURE,		/* input */
 	ADT7X10_T_ALARM_HIGH,		/* high */
 	ADT7X10_T_ALARM_LOW,		/* low */
 	ADT7X10_T_CRIT,			/* critical */
 };

 static irqreturn_t adt7x10_irq_handler(int irq, void *private)
 {
 	struct device *dev = private;
 	int status;

 	status = adt7x10_read_byte(dev, ADT7X10_STATUS);
 	if (status < 0)
 		return IRQ_HANDLED;

 	if (status & ADT7X10_STAT_T_HIGH)
 		sysfs_notify(&dev->kobj, NULL, "temp1_max_alarm");
 	if (status & ADT7X10_STAT_T_LOW)
 		sysfs_notify(&dev->kobj, NULL, "temp1_min_alarm");
 	if (status & ADT7X10_STAT_T_CRIT)
 		sysfs_notify(&dev->kobj, NULL, "temp1_crit_alarm");

 	return IRQ_HANDLED;
 }

 static int adt7x10_temp_ready(struct device *dev)
 {
 	int i, status;

 	for (i = 0; i < 6; i++) {
 		status = adt7x10_read_byte(dev, ADT7X10_STATUS);
 		if (status < 0)
 			return status;
 		if (!(status & ADT7X10_STAT_NOT_RDY))
 			return 0;
 		msleep(60);
 	}
 	return -ETIMEDOUT;
 }

 static int adt7x10_update_temp(struct device *dev)
 {
 	struct adt7x10_data *data = dev_get_drvdata(dev);
 	int ret = 0;

 	mutex_lock(&data->update_lock);

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

 		dev_dbg(dev, "Starting update\n");

 		ret = adt7x10_temp_ready(dev); /* check for new value */
 		if (ret)
 			goto abort;

 		temp = adt7x10_read_word(dev, ADT7X10_REG_TEMP[0]);
 		if (temp < 0) {
 			ret = temp;
 			dev_dbg(dev, "Failed to read value: reg %d, error %d\n",
 				ADT7X10_REG_TEMP[0], ret);
 			goto abort;
 		}
 		data->temp[0] = temp;
 		data->last_updated = jiffies;
 		data->valid = true;
 	}

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

 static int adt7x10_fill_cache(struct device *dev)
 {
 	struct adt7x10_data *data = dev_get_drvdata(dev);
 	int ret;
 	int i;

 	for (i = 1; i < ARRAY_SIZE(data->temp); i++) {
 		ret = adt7x10_read_word(dev, ADT7X10_REG_TEMP[i]);
 		if (ret < 0) {
 			dev_dbg(dev, "Failed to read value: reg %d, error %d\n",
 				ADT7X10_REG_TEMP[i], ret);
 			return ret;
 		}
 		data->temp[i] = ret;
 	}

 	ret = adt7x10_read_byte(dev, ADT7X10_T_HYST);
 	if (ret < 0) {
 		dev_dbg(dev, "Failed to read value: reg %d, error %d\n",
 				ADT7X10_T_HYST, ret);
 		return ret;
 	}
 	data->hyst = ret;

 	return 0;
 }

 static s16 ADT7X10_TEMP_TO_REG(long temp)
 {
 	return DIV_ROUND_CLOSEST(clamp_val(temp, ADT7X10_TEMP_MIN,
 					       ADT7X10_TEMP_MAX) * 128, 1000);
 }

 static int ADT7X10_REG_TO_TEMP(struct adt7x10_data *data, s16 reg)
 {
 	/* in 13 bit mode, bits 0-2 are status flags - mask them out */
 	if (!(data->config & ADT7X10_RESOLUTION))
 		reg &= ADT7X10_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 adt7x10_temp_show(struct device *dev,
 				 struct device_attribute *da, char *buf)
 {
 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 	struct adt7x10_data *data = dev_get_drvdata(dev);


 	if (attr->index == 0) {
 		int ret;

 		ret = adt7x10_update_temp(dev);
 		if (ret)
 			return ret;
 	}

 	return sprintf(buf, "%d\n", ADT7X10_REG_TO_TEMP(data,
 		       data->temp[attr->index]));
 }

 static ssize_t adt7x10_temp_store(struct device *dev,
 				  struct device_attribute *da,
 				  const char *buf, size_t count)
 {
 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 	struct adt7x10_data *data = dev_get_drvdata(dev);
 	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] = ADT7X10_TEMP_TO_REG(temp);
 	ret = adt7x10_write_word(dev, ADT7X10_REG_TEMP[nr], data->temp[nr]);
 	if (ret)
 		count = ret;
 	mutex_unlock(&data->update_lock);
 	return count;
 }

 static ssize_t adt7x10_t_hyst_show(struct device *dev,
 				   struct device_attribute *da, char *buf)
 {
 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 	struct adt7x10_data *data = dev_get_drvdata(dev);
 	int nr = attr->index;
 	int hyst;

 	hyst = (data->hyst & ADT7X10_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",
 		       ADT7X10_REG_TO_TEMP(data, data->temp[nr]) - hyst);
 }

 static ssize_t adt7x10_t_hyst_store(struct device *dev,
 				    struct device_attribute *da,
 				    const char *buf, size_t count)
 {
 	struct adt7x10_data *data = dev_get_drvdata(dev);
 	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 = ADT7X10_REG_TO_TEMP(data, data->temp[1]);
 	hyst = clamp_val(hyst, ADT7X10_TEMP_MIN, ADT7X10_TEMP_MAX);
 	data->hyst = clamp_val(DIV_ROUND_CLOSEST(limit - hyst, 1000),
 				   0, ADT7X10_T_HYST_MASK);
 	ret = adt7x10_write_byte(dev, ADT7X10_T_HYST, data->hyst);
 	if (ret)
 		return ret;

 	return count;
 }

 static ssize_t adt7x10_alarm_show(struct device *dev,
 				  struct device_attribute *da, char *buf)
 {
 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 	int ret;

 	ret = adt7x10_read_byte(dev, ADT7X10_STATUS);
 	if (ret < 0)
 		return ret;

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

 static ssize_t name_show(struct device *dev, struct device_attribute *da,
 			 char *buf)
 {
 	struct adt7x10_data *data = dev_get_drvdata(dev);

 	return sprintf(buf, "%s\n", data->name);
 }

 static SENSOR_DEVICE_ATTR_RO(temp1_input, adt7x10_temp, 0);
 static SENSOR_DEVICE_ATTR_RW(temp1_max, adt7x10_temp, 1);
 static SENSOR_DEVICE_ATTR_RW(temp1_min, adt7x10_temp, 2);
 static SENSOR_DEVICE_ATTR_RW(temp1_crit, adt7x10_temp, 3);
 static SENSOR_DEVICE_ATTR_RW(temp1_max_hyst, adt7x10_t_hyst, 1);
 static SENSOR_DEVICE_ATTR_RO(temp1_min_hyst, adt7x10_t_hyst, 2);
 static SENSOR_DEVICE_ATTR_RO(temp1_crit_hyst, adt7x10_t_hyst, 3);
 static SENSOR_DEVICE_ATTR_RO(temp1_min_alarm, adt7x10_alarm,
 			     ADT7X10_STAT_T_LOW);
 static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, adt7x10_alarm,
 			     ADT7X10_STAT_T_HIGH);
 static SENSOR_DEVICE_ATTR_RO(temp1_crit_alarm, adt7x10_alarm,
 			     ADT7X10_STAT_T_CRIT);
 static DEVICE_ATTR_RO(name);

 static struct attribute *adt7x10_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 adt7x10_group = {
 	.attrs = adt7x10_attributes,
 };

 int adt7x10_probe(struct device *dev, const char *name, int irq,
 		  const struct adt7x10_ops *ops)
 {
 	struct adt7x10_data *data;
 	int ret;

 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
 	if (!data)
 		return -ENOMEM;

 	data->ops = ops;
 	data->name = name;

 	dev_set_drvdata(dev, data);
 	mutex_init(&data->update_lock);

 	/* configure as specified */
 	ret = adt7x10_read_byte(dev, ADT7X10_CONFIG);
 	if (ret < 0) {
 		dev_dbg(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 = data->oldconfig;
 	data->config &= ~(ADT7X10_MODE_MASK | ADT7X10_CT_POLARITY |
 			ADT7X10_INT_POLARITY);
 	data->config |= ADT7X10_FULL | ADT7X10_RESOLUTION | ADT7X10_EVENT_MODE;

 	if (data->config != data->oldconfig) {
 		ret = adt7x10_write_byte(dev, ADT7X10_CONFIG, data->config);
 		if (ret)
 			return ret;
 	}
 	dev_dbg(dev, "Config %02x\n", data->config);

 	ret = adt7x10_fill_cache(dev);
 	if (ret)
 		goto exit_restore;

 	/* Register sysfs hooks */
 	ret = sysfs_create_group(&dev->kobj, &adt7x10_group);
 	if (ret)
 		goto exit_restore;

 	/*
 	 * The I2C device will already have it's own 'name' attribute, but for
 	 * the SPI device we need to register it. name will only be non NULL if
 	 * the device doesn't register the 'name' attribute on its own.
 	 */
 	if (name) {
 		ret = device_create_file(dev, &dev_attr_name);
 		if (ret)
 			goto exit_remove;
 	}

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

 	if (irq > 0) {
 		ret = request_threaded_irq(irq, NULL, adt7x10_irq_handler,
 				IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 				dev_name(dev), dev);
 		if (ret)
 			goto exit_hwmon_device_unregister;
 	}

 	return 0;

 exit_hwmon_device_unregister:
 	hwmon_device_unregister(data->hwmon_dev);
 exit_remove_name:
 	if (name)
 		device_remove_file(dev, &dev_attr_name);
 exit_remove:
 	sysfs_remove_group(&dev->kobj, &adt7x10_group);
 exit_restore:
 	adt7x10_write_byte(dev, ADT7X10_CONFIG, data->oldconfig);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(adt7x10_probe);

 int adt7x10_remove(struct device *dev, int irq)
 {
 	struct adt7x10_data *data = dev_get_drvdata(dev);

 	if (irq > 0)
 		free_irq(irq, dev);

 	hwmon_device_unregister(data->hwmon_dev);
 	if (data->name)
 		device_remove_file(dev, &dev_attr_name);
 	sysfs_remove_group(&dev->kobj, &adt7x10_group);
 	if (data->oldconfig != data->config)
 		adt7x10_write_byte(dev, ADT7X10_CONFIG, data->oldconfig);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(adt7x10_remove);

 #ifdef CONFIG_PM_SLEEP

 static int adt7x10_suspend(struct device *dev)
 {
 	struct adt7x10_data *data = dev_get_drvdata(dev);

 	return adt7x10_write_byte(dev, ADT7X10_CONFIG,
 		data->config | ADT7X10_PD);
 }

 static int adt7x10_resume(struct device *dev)
 {
 	struct adt7x10_data *data = dev_get_drvdata(dev);

 	return adt7x10_write_byte(dev, ADT7X10_CONFIG, data->config);
 }

 SIMPLE_DEV_PM_OPS(adt7x10_dev_pm_ops, adt7x10_suspend, adt7x10_resume);
 EXPORT_SYMBOL_GPL(adt7x10_dev_pm_ops);

 #endif /* CONFIG_PM_SLEEP */

 MODULE_AUTHOR("Hartmut Knaack");
 MODULE_DESCRIPTION("ADT7410/ADT7420, ADT7310/ADT7320 common code");
 MODULE_LICENSE("GPL");
	/*
	* adt7x10.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/hwmon.h>
	#include <linux/hwmon-sysfs.h>
	#include <linux/err.h>
	#include <linux/mutex.h>
	#include <linux/delay.h>
	#include <linux/interrupt.h>

	#include "adt7x10.h"

	/*
	* ADT7X10 status
	*/
	#define ADT7X10_STAT_T_LOW (1 << 4)
	#define ADT7X10_STAT_T_HIGH (1 << 5)
	#define ADT7X10_STAT_T_CRIT (1 << 6)
	#define ADT7X10_STAT_NOT_RDY (1 << 7)

	/*
	* ADT7X10 config
	*/
	#define ADT7X10_FAULT_QUEUE_MASK (1 << 0 \| 1 << 1)
	#define ADT7X10_CT_POLARITY (1 << 2)
	#define ADT7X10_INT_POLARITY (1 << 3)
	#define ADT7X10_EVENT_MODE (1 << 4)
	#define ADT7X10_MODE_MASK (1 << 5 \| 1 << 6)
	#define ADT7X10_FULL (0 << 5 \| 0 << 6)
	#define ADT7X10_PD (1 << 5 \| 1 << 6)
	#define ADT7X10_RESOLUTION (1 << 7)

	/*
	* ADT7X10 masks
	*/
	#define ADT7X10_T13_VALUE_MASK 0xFFF8
	#define ADT7X10_T_HYST_MASK 0xF

	/* straight from the datasheet */
	#define ADT7X10_TEMP_MIN (-55000)
	#define ADT7X10_TEMP_MAX 150000

	/* Each client has this additional data */
	struct adt7x10_data {
	const struct adt7x10_ops *ops;
	const char *name;
	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 */
	};

	static int adt7x10_read_byte(struct device *dev, u8 reg)
	{
	struct adt7x10_data *d = dev_get_drvdata(dev);
	return d->ops->read_byte(dev, reg);
	}

	static int adt7x10_write_byte(struct device *dev, u8 reg, u8 data)
	{
	struct adt7x10_data *d = dev_get_drvdata(dev);
	return d->ops->write_byte(dev, reg, data);
	}

	static int adt7x10_read_word(struct device *dev, u8 reg)
	{
	struct adt7x10_data *d = dev_get_drvdata(dev);
	return d->ops->read_word(dev, reg);
	}

	static int adt7x10_write_word(struct device *dev, u8 reg, u16 data)
	{
	struct adt7x10_data *d = dev_get_drvdata(dev);
	return d->ops->write_word(dev, reg, data);
	}

	static const u8 ADT7X10_REG_TEMP[4] = {
	ADT7X10_TEMPERATURE, /* input */
	ADT7X10_T_ALARM_HIGH, /* high */
	ADT7X10_T_ALARM_LOW, /* low */
	ADT7X10_T_CRIT, /* critical */
	};

	static irqreturn_t adt7x10_irq_handler(int irq, void *private)
	{
	struct device *dev = private;
	int status;

	status = adt7x10_read_byte(dev, ADT7X10_STATUS);
	if (status < 0)
	return IRQ_HANDLED;

	if (status & ADT7X10_STAT_T_HIGH)
	sysfs_notify(&dev->kobj, NULL, "temp1_max_alarm");
	if (status & ADT7X10_STAT_T_LOW)
	sysfs_notify(&dev->kobj, NULL, "temp1_min_alarm");
	if (status & ADT7X10_STAT_T_CRIT)
	sysfs_notify(&dev->kobj, NULL, "temp1_crit_alarm");

	return IRQ_HANDLED;
	}

	static int adt7x10_temp_ready(struct device *dev)
	{
	int i, status;

	for (i = 0; i < 6; i++) {
	status = adt7x10_read_byte(dev, ADT7X10_STATUS);
	if (status < 0)
	return status;
	if (!(status & ADT7X10_STAT_NOT_RDY))
	return 0;
	msleep(60);
	}
	return -ETIMEDOUT;
	}

	static int adt7x10_update_temp(struct device *dev)
	{
	struct adt7x10_data *data = dev_get_drvdata(dev);
	int ret = 0;

	mutex_lock(&data->update_lock);

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

	dev_dbg(dev, "Starting update\n");

	ret = adt7x10_temp_ready(dev); /* check for new value */
	if (ret)
	goto abort;

	temp = adt7x10_read_word(dev, ADT7X10_REG_TEMP[0]);
	if (temp < 0) {
	ret = temp;
	dev_dbg(dev, "Failed to read value: reg %d, error %d\n",
	ADT7X10_REG_TEMP[0], ret);
	goto abort;
	}
	data->temp[0] = temp;
	data->last_updated = jiffies;
	data->valid = true;
	}

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

	static int adt7x10_fill_cache(struct device *dev)
	{
	struct adt7x10_data *data = dev_get_drvdata(dev);
	int ret;
	int i;

	for (i = 1; i < ARRAY_SIZE(data->temp); i++) {
	ret = adt7x10_read_word(dev, ADT7X10_REG_TEMP[i]);
	if (ret < 0) {
	dev_dbg(dev, "Failed to read value: reg %d, error %d\n",
	ADT7X10_REG_TEMP[i], ret);
	return ret;
	}
	data->temp[i] = ret;
	}

	ret = adt7x10_read_byte(dev, ADT7X10_T_HYST);
	if (ret < 0) {
	dev_dbg(dev, "Failed to read value: reg %d, error %d\n",
	ADT7X10_T_HYST, ret);
	return ret;
	}
	data->hyst = ret;

	return 0;
	}

	static s16 ADT7X10_TEMP_TO_REG(long temp)
	{
	return DIV_ROUND_CLOSEST(clamp_val(temp, ADT7X10_TEMP_MIN,
	ADT7X10_TEMP_MAX) * 128, 1000);
	}

	static int ADT7X10_REG_TO_TEMP(struct adt7x10_data *data, s16 reg)
	{
	/* in 13 bit mode, bits 0-2 are status flags - mask them out */
	if (!(data->config & ADT7X10_RESOLUTION))
	reg &= ADT7X10_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 adt7x10_temp_show(struct device *dev,
	struct device_attribute da, char buf)
	{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
	struct adt7x10_data *data = dev_get_drvdata(dev);


	if (attr->index == 0) {
	int ret;

	ret = adt7x10_update_temp(dev);
	if (ret)
	return ret;
	}

	return sprintf(buf, "%d\n", ADT7X10_REG_TO_TEMP(data,
	data->temp[attr->index]));
	}

	static ssize_t adt7x10_temp_store(struct device *dev,
	struct device_attribute *da,
	const char *buf, size_t count)
	{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
	struct adt7x10_data *data = dev_get_drvdata(dev);
	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] = ADT7X10_TEMP_TO_REG(temp);
	ret = adt7x10_write_word(dev, ADT7X10_REG_TEMP[nr], data->temp[nr]);
	if (ret)
	count = ret;
	mutex_unlock(&data->update_lock);
	return count;
	}

	static ssize_t adt7x10_t_hyst_show(struct device *dev,
	struct device_attribute da, char buf)
	{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
	struct adt7x10_data *data = dev_get_drvdata(dev);
	int nr = attr->index;
	int hyst;

	hyst = (data->hyst & ADT7X10_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",
	ADT7X10_REG_TO_TEMP(data, data->temp[nr]) - hyst);
	}

	static ssize_t adt7x10_t_hyst_store(struct device *dev,
	struct device_attribute *da,
	const char *buf, size_t count)
	{
	struct adt7x10_data *data = dev_get_drvdata(dev);
	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 = ADT7X10_REG_TO_TEMP(data, data->temp[1]);
	hyst = clamp_val(hyst, ADT7X10_TEMP_MIN, ADT7X10_TEMP_MAX);
	data->hyst = clamp_val(DIV_ROUND_CLOSEST(limit - hyst, 1000),
	0, ADT7X10_T_HYST_MASK);
	ret = adt7x10_write_byte(dev, ADT7X10_T_HYST, data->hyst);
	if (ret)
	return ret;

	return count;
	}

	static ssize_t adt7x10_alarm_show(struct device *dev,
	struct device_attribute da, char buf)
	{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
	int ret;

	ret = adt7x10_read_byte(dev, ADT7X10_STATUS);
	if (ret < 0)
	return ret;

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

	static ssize_t name_show(struct device dev, struct device_attribute da,
	char *buf)
	{
	struct adt7x10_data *data = dev_get_drvdata(dev);

	return sprintf(buf, "%s\n", data->name);
	}

	static SENSOR_DEVICE_ATTR_RO(temp1_input, adt7x10_temp, 0);
	static SENSOR_DEVICE_ATTR_RW(temp1_max, adt7x10_temp, 1);
	static SENSOR_DEVICE_ATTR_RW(temp1_min, adt7x10_temp, 2);
	static SENSOR_DEVICE_ATTR_RW(temp1_crit, adt7x10_temp, 3);
	static SENSOR_DEVICE_ATTR_RW(temp1_max_hyst, adt7x10_t_hyst, 1);
	static SENSOR_DEVICE_ATTR_RO(temp1_min_hyst, adt7x10_t_hyst, 2);
	static SENSOR_DEVICE_ATTR_RO(temp1_crit_hyst, adt7x10_t_hyst, 3);
	static SENSOR_DEVICE_ATTR_RO(temp1_min_alarm, adt7x10_alarm,
	ADT7X10_STAT_T_LOW);
	static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, adt7x10_alarm,
	ADT7X10_STAT_T_HIGH);
	static SENSOR_DEVICE_ATTR_RO(temp1_crit_alarm, adt7x10_alarm,
	ADT7X10_STAT_T_CRIT);
	static DEVICE_ATTR_RO(name);

	static struct attribute *adt7x10_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 adt7x10_group = {
	.attrs = adt7x10_attributes,
	};

	int adt7x10_probe(struct device dev, const char name, int irq,
	const struct adt7x10_ops *ops)
	{
	struct adt7x10_data *data;
	int ret;

	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
	if (!data)
	return -ENOMEM;

	data->ops = ops;
	data->name = name;

	dev_set_drvdata(dev, data);
	mutex_init(&data->update_lock);

	/* configure as specified */
	ret = adt7x10_read_byte(dev, ADT7X10_CONFIG);
	if (ret < 0) {
	dev_dbg(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 = data->oldconfig;
	data->config &= ~(ADT7X10_MODE_MASK \| ADT7X10_CT_POLARITY \|
	ADT7X10_INT_POLARITY);
	data->config \|= ADT7X10_FULL \| ADT7X10_RESOLUTION \| ADT7X10_EVENT_MODE;

	if (data->config != data->oldconfig) {
	ret = adt7x10_write_byte(dev, ADT7X10_CONFIG, data->config);
	if (ret)
	return ret;
	}
	dev_dbg(dev, "Config %02x\n", data->config);

	ret = adt7x10_fill_cache(dev);
	if (ret)
	goto exit_restore;

	/* Register sysfs hooks */
	ret = sysfs_create_group(&dev->kobj, &adt7x10_group);
	if (ret)
	goto exit_restore;

	/*
	* The I2C device will already have it's own 'name' attribute, but for
	* the SPI device we need to register it. name will only be non NULL if
	* the device doesn't register the 'name' attribute on its own.
	*/
	if (name) {
	ret = device_create_file(dev, &dev_attr_name);
	if (ret)
	goto exit_remove;
	}

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

	if (irq > 0) {
	ret = request_threaded_irq(irq, NULL, adt7x10_irq_handler,
	IRQF_TRIGGER_FALLING \| IRQF_ONESHOT,
	dev_name(dev), dev);
	if (ret)
	goto exit_hwmon_device_unregister;
	}

	return 0;

	exit_hwmon_device_unregister:
	hwmon_device_unregister(data->hwmon_dev);
	exit_remove_name:
	if (name)
	device_remove_file(dev, &dev_attr_name);
	exit_remove:
	sysfs_remove_group(&dev->kobj, &adt7x10_group);
	exit_restore:
	adt7x10_write_byte(dev, ADT7X10_CONFIG, data->oldconfig);
	return ret;
	}
	EXPORT_SYMBOL_GPL(adt7x10_probe);

	int adt7x10_remove(struct device *dev, int irq)
	{
	struct adt7x10_data *data = dev_get_drvdata(dev);

	if (irq > 0)
	free_irq(irq, dev);

	hwmon_device_unregister(data->hwmon_dev);
	if (data->name)
	device_remove_file(dev, &dev_attr_name);
	sysfs_remove_group(&dev->kobj, &adt7x10_group);
	if (data->oldconfig != data->config)
	adt7x10_write_byte(dev, ADT7X10_CONFIG, data->oldconfig);
	return 0;
	}
	EXPORT_SYMBOL_GPL(adt7x10_remove);

	#ifdef CONFIG_PM_SLEEP

	static int adt7x10_suspend(struct device *dev)
	{
	struct adt7x10_data *data = dev_get_drvdata(dev);

	return adt7x10_write_byte(dev, ADT7X10_CONFIG,
	data->config \| ADT7X10_PD);
	}

	static int adt7x10_resume(struct device *dev)
	{
	struct adt7x10_data *data = dev_get_drvdata(dev);

	return adt7x10_write_byte(dev, ADT7X10_CONFIG, data->config);
	}

	SIMPLE_DEV_PM_OPS(adt7x10_dev_pm_ops, adt7x10_suspend, adt7x10_resume);
	EXPORT_SYMBOL_GPL(adt7x10_dev_pm_ops);

	#endif /* CONFIG_PM_SLEEP */

	MODULE_AUTHOR("Hartmut Knaack");
	MODULE_DESCRIPTION("ADT7410/ADT7420, ADT7310/ADT7320 common code");
	MODULE_LICENSE("GPL");