drivers/hwmon/adt7411.c - kernel/msm-4.9 - Gitiles

 /*
  *  Driver for the ADT7411 (I2C/SPI 8 channel 10 bit ADC & temperature-sensor)
  *
  *  Copyright (C) 2008, 2010 Pengutronix
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License version 2 as
  *  published by the Free Software Foundation.
  *
  *  TODO: SPI, support for external temperature sensor
  * 	  use power-down mode for suspend?, interrupt handling?
  */

 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/err.h>
 #include <linux/delay.h>
 #include <linux/mutex.h>
 #include <linux/jiffies.h>
 #include <linux/i2c.h>
 #include <linux/hwmon.h>
 #include <linux/hwmon-sysfs.h>

 #define ADT7411_REG_INT_TEMP_VDD_LSB		0x03
 #define ADT7411_REG_EXT_TEMP_AIN14_LSB		0x04
 #define ADT7411_REG_VDD_MSB			0x06
 #define ADT7411_REG_INT_TEMP_MSB		0x07
 #define ADT7411_REG_EXT_TEMP_AIN1_MSB		0x08

 #define ADT7411_REG_CFG1			0x18
 #define ADT7411_CFG1_START_MONITOR		(1 << 0)

 #define ADT7411_REG_CFG2			0x19
 #define ADT7411_CFG2_DISABLE_AVG		(1 << 5)

 #define ADT7411_REG_CFG3			0x1a
 #define ADT7411_CFG3_ADC_CLK_225		(1 << 0)
 #define ADT7411_CFG3_REF_VDD			(1 << 4)

 #define ADT7411_REG_DEVICE_ID			0x4d
 #define ADT7411_REG_MANUFACTURER_ID		0x4e

 #define ADT7411_DEVICE_ID			0x2
 #define ADT7411_MANUFACTURER_ID			0x41

 static const unsigned short normal_i2c[] = { 0x48, 0x4a, 0x4b, I2C_CLIENT_END };

 struct adt7411_data {
 	struct mutex device_lock;	/* for "atomic" device accesses */
 	struct mutex update_lock;
 	unsigned long next_update;
 	int vref_cached;
 	struct device *hwmon_dev;
 };

 /*
  * When reading a register containing (up to 4) lsb, all associated
  * msb-registers get locked by the hardware. After _one_ of those msb is read,
  * _all_ are unlocked. In order to use this locking correctly, reading lsb/msb
  * is protected here with a mutex, too.
  */
 static int adt7411_read_10_bit(struct i2c_client *client, u8 lsb_reg,
 				u8 msb_reg, u8 lsb_shift)
 {
 	struct adt7411_data *data = i2c_get_clientdata(client);
 	int val, tmp;

 	mutex_lock(&data->device_lock);

 	val = i2c_smbus_read_byte_data(client, lsb_reg);
 	if (val < 0)
 		goto exit_unlock;

 	tmp = (val >> lsb_shift) & 3;
 	val = i2c_smbus_read_byte_data(client, msb_reg);

 	if (val >= 0)
 		val = (val << 2) | tmp;

  exit_unlock:
 	mutex_unlock(&data->device_lock);

 	return val;
 }

 static int adt7411_modify_bit(struct i2c_client *client, u8 reg, u8 bit,
 				bool flag)
 {
 	struct adt7411_data *data = i2c_get_clientdata(client);
 	int ret, val;

 	mutex_lock(&data->device_lock);

 	ret = i2c_smbus_read_byte_data(client, reg);
 	if (ret < 0)
 		goto exit_unlock;

 	if (flag)
 		val = ret | bit;
 	else
 		val = ret & ~bit;

 	ret = i2c_smbus_write_byte_data(client, reg, val);

  exit_unlock:
 	mutex_unlock(&data->device_lock);
 	return ret;
 }

 static ssize_t adt7411_show_vdd(struct device *dev,
 				struct device_attribute *attr, char *buf)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	int ret = adt7411_read_10_bit(client, ADT7411_REG_INT_TEMP_VDD_LSB,
 			ADT7411_REG_VDD_MSB, 2);

 	return ret < 0 ? ret : sprintf(buf, "%u\n", ret * 7000 / 1024);
 }

 static ssize_t adt7411_show_temp(struct device *dev,
 			struct device_attribute *attr, char *buf)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	int val = adt7411_read_10_bit(client, ADT7411_REG_INT_TEMP_VDD_LSB,
 			ADT7411_REG_INT_TEMP_MSB, 0);

 	if (val < 0)
 		return val;

 	val = val & 0x200 ? val - 0x400 : val; /* 10 bit signed */

 	return sprintf(buf, "%d\n", val * 250);
 }

 static ssize_t adt7411_show_input(struct device *dev,
 				  struct device_attribute *attr, char *buf)
 {
 	int nr = to_sensor_dev_attr(attr)->index;
 	struct i2c_client *client = to_i2c_client(dev);
 	struct adt7411_data *data = i2c_get_clientdata(client);
 	int val;
 	u8 lsb_reg, lsb_shift;

 	mutex_lock(&data->update_lock);
 	if (time_after_eq(jiffies, data->next_update)) {
 		val = i2c_smbus_read_byte_data(client, ADT7411_REG_CFG3);
 		if (val < 0)
 			goto exit_unlock;

 		if (val & ADT7411_CFG3_REF_VDD) {
 			val = adt7411_read_10_bit(client,
 					ADT7411_REG_INT_TEMP_VDD_LSB,
 					ADT7411_REG_VDD_MSB, 2);
 			if (val < 0)
 				goto exit_unlock;

 			data->vref_cached = val * 7000 / 1024;
 		} else {
 			data->vref_cached = 2250;
 		}

 		data->next_update = jiffies + HZ;
 	}

 	lsb_reg = ADT7411_REG_EXT_TEMP_AIN14_LSB + (nr >> 2);
 	lsb_shift = 2 * (nr & 0x03);
 	val = adt7411_read_10_bit(client, lsb_reg,
 			ADT7411_REG_EXT_TEMP_AIN1_MSB + nr, lsb_shift);
 	if (val < 0)
 		goto exit_unlock;

 	val = sprintf(buf, "%u\n", val * data->vref_cached / 1024);
  exit_unlock:
 	mutex_unlock(&data->update_lock);
 	return val;
 }

 static ssize_t adt7411_show_bit(struct device *dev,
 				struct device_attribute *attr, char *buf)
 {
 	struct sensor_device_attribute_2 *attr2 = to_sensor_dev_attr_2(attr);
 	struct i2c_client *client = to_i2c_client(dev);
 	int ret = i2c_smbus_read_byte_data(client, attr2->index);

 	return ret < 0 ? ret : sprintf(buf, "%u\n", !!(ret & attr2->nr));
 }

 static ssize_t adt7411_set_bit(struct device *dev,
 			       struct device_attribute *attr, const char *buf,
 			       size_t count)
 {
 	struct sensor_device_attribute_2 *s_attr2 = to_sensor_dev_attr_2(attr);
 	struct i2c_client *client = to_i2c_client(dev);
 	struct adt7411_data *data = i2c_get_clientdata(client);
 	int ret;
 	unsigned long flag;

 	ret = strict_strtoul(buf, 0, &flag);
 	if (ret || flag > 1)
 		return -EINVAL;

 	ret = adt7411_modify_bit(client, s_attr2->index, s_attr2->nr, flag);

 	/* force update */
 	mutex_lock(&data->update_lock);
 	data->next_update = jiffies;
 	mutex_unlock(&data->update_lock);

 	return ret < 0 ? ret : count;
 }

 #define ADT7411_BIT_ATTR(__name, __reg, __bit) \
 	SENSOR_DEVICE_ATTR_2(__name, S_IRUGO | S_IWUSR, adt7411_show_bit, \
 	adt7411_set_bit, __bit, __reg)

 static DEVICE_ATTR(temp1_input, S_IRUGO, adt7411_show_temp, NULL);
 static DEVICE_ATTR(in0_input, S_IRUGO, adt7411_show_vdd, NULL);
 static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, adt7411_show_input, NULL, 0);
 static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, adt7411_show_input, NULL, 1);
 static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, adt7411_show_input, NULL, 2);
 static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, adt7411_show_input, NULL, 3);
 static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, adt7411_show_input, NULL, 4);
 static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO, adt7411_show_input, NULL, 5);
 static SENSOR_DEVICE_ATTR(in7_input, S_IRUGO, adt7411_show_input, NULL, 6);
 static SENSOR_DEVICE_ATTR(in8_input, S_IRUGO, adt7411_show_input, NULL, 7);
 static ADT7411_BIT_ATTR(no_average, ADT7411_REG_CFG2, ADT7411_CFG2_DISABLE_AVG);
 static ADT7411_BIT_ATTR(fast_sampling, ADT7411_REG_CFG3, ADT7411_CFG3_ADC_CLK_225);
 static ADT7411_BIT_ATTR(adc_ref_vdd, ADT7411_REG_CFG3, ADT7411_CFG3_REF_VDD);

 static struct attribute *adt7411_attrs[] = {
 	&dev_attr_temp1_input.attr,
 	&dev_attr_in0_input.attr,
 	&sensor_dev_attr_in1_input.dev_attr.attr,
 	&sensor_dev_attr_in2_input.dev_attr.attr,
 	&sensor_dev_attr_in3_input.dev_attr.attr,
 	&sensor_dev_attr_in4_input.dev_attr.attr,
 	&sensor_dev_attr_in5_input.dev_attr.attr,
 	&sensor_dev_attr_in6_input.dev_attr.attr,
 	&sensor_dev_attr_in7_input.dev_attr.attr,
 	&sensor_dev_attr_in8_input.dev_attr.attr,
 	&sensor_dev_attr_no_average.dev_attr.attr,
 	&sensor_dev_attr_fast_sampling.dev_attr.attr,
 	&sensor_dev_attr_adc_ref_vdd.dev_attr.attr,
 	NULL
 };

 static const struct attribute_group adt7411_attr_grp = {
 	.attrs = adt7411_attrs,
 };

 static int adt7411_detect(struct i2c_client *client,
 			  struct i2c_board_info *info)
 {
 	int val;

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

 	val = i2c_smbus_read_byte_data(client, ADT7411_REG_MANUFACTURER_ID);
 	if (val < 0 || val != ADT7411_MANUFACTURER_ID) {
 		dev_dbg(&client->dev, "Wrong manufacturer ID. Got %d, "
 			"expected %d\n", val, ADT7411_MANUFACTURER_ID);
 		return -ENODEV;
 	}

 	val = i2c_smbus_read_byte_data(client, ADT7411_REG_DEVICE_ID);
 	if (val < 0 || val != ADT7411_DEVICE_ID) {
 		dev_dbg(&client->dev, "Wrong device ID. Got %d, "
 			"expected %d\n", val, ADT7411_DEVICE_ID);
 		return -ENODEV;
 	}

 	strlcpy(info->type, "adt7411", I2C_NAME_SIZE);

 	return 0;
 }

 static int __devinit adt7411_probe(struct i2c_client *client,
 				   const struct i2c_device_id *id)
 {
 	struct adt7411_data *data;
 	int ret;

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

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

 	ret = adt7411_modify_bit(client, ADT7411_REG_CFG1,
 				 ADT7411_CFG1_START_MONITOR, 1);
 	if (ret < 0)
 		goto exit_free;

 	/* force update on first occasion */
 	data->next_update = jiffies;

 	ret = sysfs_create_group(&client->dev.kobj, &adt7411_attr_grp);
 	if (ret)
 		goto exit_free;

 	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, "successfully registered\n");

 	return 0;

  exit_remove:
 	sysfs_remove_group(&client->dev.kobj, &adt7411_attr_grp);
  exit_free:
 	i2c_set_clientdata(client, NULL);
 	kfree(data);
 	return ret;
 }

 static int __devexit adt7411_remove(struct i2c_client *client)
 {
 	struct adt7411_data *data = i2c_get_clientdata(client);

 	hwmon_device_unregister(data->hwmon_dev);
 	sysfs_remove_group(&client->dev.kobj, &adt7411_attr_grp);
 	i2c_set_clientdata(client, NULL);
 	kfree(data);
 	return 0;
 }

 static const struct i2c_device_id adt7411_id[] = {
 	{ "adt7411", 0 },
 	{ }
 };

 static struct i2c_driver adt7411_driver = {
 	.driver		= {
 		.name		= "adt7411",
 	},
 	.probe  = adt7411_probe,
 	.remove	= __devexit_p(adt7411_remove),
 	.id_table = adt7411_id,
 	.detect = adt7411_detect,
 	.address_list = normal_i2c,
 	.class = I2C_CLASS_HWMON,
 };

 static int __init sensors_adt7411_init(void)
 {
 	return i2c_add_driver(&adt7411_driver);
 }
 module_init(sensors_adt7411_init)

 static void __exit sensors_adt7411_exit(void)
 {
 	i2c_del_driver(&adt7411_driver);
 }
 module_exit(sensors_adt7411_exit)

 MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de> and "
 	"Wolfram Sang <w.sang@pengutronix.de>");
 MODULE_DESCRIPTION("ADT7411 driver");
 MODULE_LICENSE("GPL v2");
	/*
	* Driver for the ADT7411 (I2C/SPI 8 channel 10 bit ADC & temperature-sensor)
	*
	* Copyright (C) 2008, 2010 Pengutronix
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*
	* TODO: SPI, support for external temperature sensor
	* use power-down mode for suspend?, interrupt handling?
	*/

	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/init.h>
	#include <linux/err.h>
	#include <linux/delay.h>
	#include <linux/mutex.h>
	#include <linux/jiffies.h>
	#include <linux/i2c.h>
	#include <linux/hwmon.h>
	#include <linux/hwmon-sysfs.h>

	#define ADT7411_REG_INT_TEMP_VDD_LSB 0x03
	#define ADT7411_REG_EXT_TEMP_AIN14_LSB 0x04
	#define ADT7411_REG_VDD_MSB 0x06
	#define ADT7411_REG_INT_TEMP_MSB 0x07
	#define ADT7411_REG_EXT_TEMP_AIN1_MSB 0x08

	#define ADT7411_REG_CFG1 0x18
	#define ADT7411_CFG1_START_MONITOR (1 << 0)

	#define ADT7411_REG_CFG2 0x19
	#define ADT7411_CFG2_DISABLE_AVG (1 << 5)

	#define ADT7411_REG_CFG3 0x1a
	#define ADT7411_CFG3_ADC_CLK_225 (1 << 0)
	#define ADT7411_CFG3_REF_VDD (1 << 4)

	#define ADT7411_REG_DEVICE_ID 0x4d
	#define ADT7411_REG_MANUFACTURER_ID 0x4e

	#define ADT7411_DEVICE_ID 0x2
	#define ADT7411_MANUFACTURER_ID 0x41

	static const unsigned short normal_i2c[] = { 0x48, 0x4a, 0x4b, I2C_CLIENT_END };

	struct adt7411_data {
	struct mutex device_lock; /* for "atomic" device accesses */
	struct mutex update_lock;
	unsigned long next_update;
	int vref_cached;
	struct device *hwmon_dev;
	};

	/*
	* When reading a register containing (up to 4) lsb, all associated
	* msb-registers get locked by the hardware. After _one_ of those msb is read,
	* _all_ are unlocked. In order to use this locking correctly, reading lsb/msb
	* is protected here with a mutex, too.
	*/
	static int adt7411_read_10_bit(struct i2c_client *client, u8 lsb_reg,
	u8 msb_reg, u8 lsb_shift)
	{
	struct adt7411_data *data = i2c_get_clientdata(client);
	int val, tmp;

	mutex_lock(&data->device_lock);

	val = i2c_smbus_read_byte_data(client, lsb_reg);
	if (val < 0)
	goto exit_unlock;

	tmp = (val >> lsb_shift) & 3;
	val = i2c_smbus_read_byte_data(client, msb_reg);

	if (val >= 0)
	val = (val << 2) \| tmp;

	exit_unlock:
	mutex_unlock(&data->device_lock);

	return val;
	}

	static int adt7411_modify_bit(struct i2c_client *client, u8 reg, u8 bit,
	bool flag)
	{
	struct adt7411_data *data = i2c_get_clientdata(client);
	int ret, val;

	mutex_lock(&data->device_lock);

	ret = i2c_smbus_read_byte_data(client, reg);
	if (ret < 0)
	goto exit_unlock;

	if (flag)
	val = ret \| bit;
	else
	val = ret & ~bit;

	ret = i2c_smbus_write_byte_data(client, reg, val);

	exit_unlock:
	mutex_unlock(&data->device_lock);
	return ret;
	}

	static ssize_t adt7411_show_vdd(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct i2c_client *client = to_i2c_client(dev);
	int ret = adt7411_read_10_bit(client, ADT7411_REG_INT_TEMP_VDD_LSB,
	ADT7411_REG_VDD_MSB, 2);

	return ret < 0 ? ret : sprintf(buf, "%u\n", ret * 7000 / 1024);
	}

	static ssize_t adt7411_show_temp(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct i2c_client *client = to_i2c_client(dev);
	int val = adt7411_read_10_bit(client, ADT7411_REG_INT_TEMP_VDD_LSB,
	ADT7411_REG_INT_TEMP_MSB, 0);

	if (val < 0)
	return val;

	val = val & 0x200 ? val - 0x400 : val; /* 10 bit signed */

	return sprintf(buf, "%d\n", val * 250);
	}

	static ssize_t adt7411_show_input(struct device *dev,
	struct device_attribute attr, char buf)
	{
	int nr = to_sensor_dev_attr(attr)->index;
	struct i2c_client *client = to_i2c_client(dev);
	struct adt7411_data *data = i2c_get_clientdata(client);
	int val;
	u8 lsb_reg, lsb_shift;

	mutex_lock(&data->update_lock);
	if (time_after_eq(jiffies, data->next_update)) {
	val = i2c_smbus_read_byte_data(client, ADT7411_REG_CFG3);
	if (val < 0)
	goto exit_unlock;

	if (val & ADT7411_CFG3_REF_VDD) {
	val = adt7411_read_10_bit(client,
	ADT7411_REG_INT_TEMP_VDD_LSB,
	ADT7411_REG_VDD_MSB, 2);
	if (val < 0)
	goto exit_unlock;

	data->vref_cached = val * 7000 / 1024;
	} else {
	data->vref_cached = 2250;
	}

	data->next_update = jiffies + HZ;
	}

	lsb_reg = ADT7411_REG_EXT_TEMP_AIN14_LSB + (nr >> 2);
	lsb_shift = 2 * (nr & 0x03);
	val = adt7411_read_10_bit(client, lsb_reg,
	ADT7411_REG_EXT_TEMP_AIN1_MSB + nr, lsb_shift);
	if (val < 0)
	goto exit_unlock;

	val = sprintf(buf, "%u\n", val * data->vref_cached / 1024);
	exit_unlock:
	mutex_unlock(&data->update_lock);
	return val;
	}

	static ssize_t adt7411_show_bit(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct sensor_device_attribute_2 *attr2 = to_sensor_dev_attr_2(attr);
	struct i2c_client *client = to_i2c_client(dev);
	int ret = i2c_smbus_read_byte_data(client, attr2->index);

	return ret < 0 ? ret : sprintf(buf, "%u\n", !!(ret & attr2->nr));
	}

	static ssize_t adt7411_set_bit(struct device *dev,
	struct device_attribute attr, const char buf,
	size_t count)
	{
	struct sensor_device_attribute_2 *s_attr2 = to_sensor_dev_attr_2(attr);
	struct i2c_client *client = to_i2c_client(dev);
	struct adt7411_data *data = i2c_get_clientdata(client);
	int ret;
	unsigned long flag;

	ret = strict_strtoul(buf, 0, &flag);
	if (ret \|\| flag > 1)
	return -EINVAL;

	ret = adt7411_modify_bit(client, s_attr2->index, s_attr2->nr, flag);

	/* force update */
	mutex_lock(&data->update_lock);
	data->next_update = jiffies;
	mutex_unlock(&data->update_lock);

	return ret < 0 ? ret : count;
	}

	#define ADT7411_BIT_ATTR(__name, __reg, __bit) \
	SENSOR_DEVICE_ATTR_2(__name, S_IRUGO \| S_IWUSR, adt7411_show_bit, \
	adt7411_set_bit, __bit, __reg)

	static DEVICE_ATTR(temp1_input, S_IRUGO, adt7411_show_temp, NULL);
	static DEVICE_ATTR(in0_input, S_IRUGO, adt7411_show_vdd, NULL);
	static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, adt7411_show_input, NULL, 0);
	static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, adt7411_show_input, NULL, 1);
	static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, adt7411_show_input, NULL, 2);
	static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, adt7411_show_input, NULL, 3);
	static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, adt7411_show_input, NULL, 4);
	static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO, adt7411_show_input, NULL, 5);
	static SENSOR_DEVICE_ATTR(in7_input, S_IRUGO, adt7411_show_input, NULL, 6);
	static SENSOR_DEVICE_ATTR(in8_input, S_IRUGO, adt7411_show_input, NULL, 7);
	static ADT7411_BIT_ATTR(no_average, ADT7411_REG_CFG2, ADT7411_CFG2_DISABLE_AVG);
	static ADT7411_BIT_ATTR(fast_sampling, ADT7411_REG_CFG3, ADT7411_CFG3_ADC_CLK_225);
	static ADT7411_BIT_ATTR(adc_ref_vdd, ADT7411_REG_CFG3, ADT7411_CFG3_REF_VDD);

	static struct attribute *adt7411_attrs[] = {
	&dev_attr_temp1_input.attr,
	&dev_attr_in0_input.attr,
	&sensor_dev_attr_in1_input.dev_attr.attr,
	&sensor_dev_attr_in2_input.dev_attr.attr,
	&sensor_dev_attr_in3_input.dev_attr.attr,
	&sensor_dev_attr_in4_input.dev_attr.attr,
	&sensor_dev_attr_in5_input.dev_attr.attr,
	&sensor_dev_attr_in6_input.dev_attr.attr,
	&sensor_dev_attr_in7_input.dev_attr.attr,
	&sensor_dev_attr_in8_input.dev_attr.attr,
	&sensor_dev_attr_no_average.dev_attr.attr,
	&sensor_dev_attr_fast_sampling.dev_attr.attr,
	&sensor_dev_attr_adc_ref_vdd.dev_attr.attr,
	NULL
	};

	static const struct attribute_group adt7411_attr_grp = {
	.attrs = adt7411_attrs,
	};

	static int adt7411_detect(struct i2c_client *client,
	struct i2c_board_info *info)
	{
	int val;

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

	val = i2c_smbus_read_byte_data(client, ADT7411_REG_MANUFACTURER_ID);
	if (val < 0 \|\| val != ADT7411_MANUFACTURER_ID) {
	dev_dbg(&client->dev, "Wrong manufacturer ID. Got %d, "
	"expected %d\n", val, ADT7411_MANUFACTURER_ID);
	return -ENODEV;
	}

	val = i2c_smbus_read_byte_data(client, ADT7411_REG_DEVICE_ID);
	if (val < 0 \|\| val != ADT7411_DEVICE_ID) {
	dev_dbg(&client->dev, "Wrong device ID. Got %d, "
	"expected %d\n", val, ADT7411_DEVICE_ID);
	return -ENODEV;
	}

	strlcpy(info->type, "adt7411", I2C_NAME_SIZE);

	return 0;
	}

	static int __devinit adt7411_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	struct adt7411_data *data;
	int ret;

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

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

	ret = adt7411_modify_bit(client, ADT7411_REG_CFG1,
	ADT7411_CFG1_START_MONITOR, 1);
	if (ret < 0)
	goto exit_free;

	/* force update on first occasion */
	data->next_update = jiffies;

	ret = sysfs_create_group(&client->dev.kobj, &adt7411_attr_grp);
	if (ret)
	goto exit_free;

	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, "successfully registered\n");

	return 0;

	exit_remove:
	sysfs_remove_group(&client->dev.kobj, &adt7411_attr_grp);
	exit_free:
	i2c_set_clientdata(client, NULL);
	kfree(data);
	return ret;
	}

	static int __devexit adt7411_remove(struct i2c_client *client)
	{
	struct adt7411_data *data = i2c_get_clientdata(client);

	hwmon_device_unregister(data->hwmon_dev);
	sysfs_remove_group(&client->dev.kobj, &adt7411_attr_grp);
	i2c_set_clientdata(client, NULL);
	kfree(data);
	return 0;
	}

	static const struct i2c_device_id adt7411_id[] = {
	{ "adt7411", 0 },
	{ }
	};

	static struct i2c_driver adt7411_driver = {
	.driver = {
	.name = "adt7411",
	},
	.probe = adt7411_probe,
	.remove = __devexit_p(adt7411_remove),
	.id_table = adt7411_id,
	.detect = adt7411_detect,
	.address_list = normal_i2c,
	.class = I2C_CLASS_HWMON,
	};

	static int __init sensors_adt7411_init(void)
	{
	return i2c_add_driver(&adt7411_driver);
	}
	module_init(sensors_adt7411_init)

	static void __exit sensors_adt7411_exit(void)
	{
	i2c_del_driver(&adt7411_driver);
	}
	module_exit(sensors_adt7411_exit)

	MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de> and "
	"Wolfram Sang <w.sang@pengutronix.de>");
	MODULE_DESCRIPTION("ADT7411 driver");
	MODULE_LICENSE("GPL v2");