drivers/hwmon/lm75.c - fp2-dev/kernel/msm - Gitiles

 /*
     lm75.c - Part of lm_sensors, Linux kernel modules for hardware
              monitoring
     Copyright (c) 1998, 1999  Frodo Looijaard <frodol@dds.nl>

     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 "lm75.h"


 /*
  * This driver handles the LM75 and compatible digital temperature sensors.
  */

 enum lm75_type {		/* keep sorted in alphabetical order */
 	ds1775,
 	ds75,
 	lm75,
 	lm75a,
 	max6625,
 	max6626,
 	mcp980x,
 	stds75,
 	tcn75,
 	tmp100,
 	tmp101,
 	tmp105,
 	tmp175,
 	tmp275,
 	tmp75,
 };

 /* Addresses scanned */
 static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
 					0x4d, 0x4e, 0x4f, I2C_CLIENT_END };


 /* The LM75 registers */
 #define LM75_REG_CONF		0x01
 static const u8 LM75_REG_TEMP[3] = {
 	0x00,		/* input */
 	0x03,		/* max */
 	0x02,		/* hyst */
 };

 /* Each client has this additional data */
 struct lm75_data {
 	struct device		*hwmon_dev;
 	struct mutex		update_lock;
 	u8			orig_conf;
 	char			valid;		/* !=0 if registers are valid */
 	unsigned long		last_updated;	/* In jiffies */
 	u16			temp[3];	/* Register values,
 						   0 = input
 						   1 = max
 						   2 = hyst */
 };

 static int lm75_read_value(struct i2c_client *client, u8 reg);
 static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value);
 static struct lm75_data *lm75_update_device(struct device *dev);


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

 /* sysfs attributes for hwmon */

 static ssize_t show_temp(struct device *dev, struct device_attribute *da,
 			 char *buf)
 {
 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 	struct lm75_data *data = lm75_update_device(dev);
 	return sprintf(buf, "%d\n",
 		       LM75_TEMP_FROM_REG(data->temp[attr->index]));
 }

 static ssize_t 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 lm75_data *data = i2c_get_clientdata(client);
 	int nr = attr->index;
 	long temp;
 	int error;

 	error = strict_strtol(buf, 10, &temp);
 	if (error)
 		return error;

 	mutex_lock(&data->update_lock);
 	data->temp[nr] = LM75_TEMP_TO_REG(temp);
 	lm75_write_value(client, LM75_REG_TEMP[nr], data->temp[nr]);
 	mutex_unlock(&data->update_lock);
 	return count;
 }

 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
 			show_temp, set_temp, 1);
 static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO,
 			show_temp, set_temp, 2);
 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);

 static struct attribute *lm75_attributes[] = {
 	&sensor_dev_attr_temp1_input.dev_attr.attr,
 	&sensor_dev_attr_temp1_max.dev_attr.attr,
 	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,

 	NULL
 };

 static const struct attribute_group lm75_group = {
 	.attrs = lm75_attributes,
 };

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

 /* device probe and removal */

 static int
 lm75_probe(struct i2c_client *client, const struct i2c_device_id *id)
 {
 	struct lm75_data *data;
 	int status;
 	u8 set_mask, clr_mask;
 	int new;

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

 	data = kzalloc(sizeof(struct lm75_data), GFP_KERNEL);
 	if (!data)
 		return -ENOMEM;

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

 	/* Set to LM75 resolution (9 bits, 1/2 degree C) and range.
 	 * Then tweak to be more precise when appropriate.
 	 */
 	set_mask = 0;
 	clr_mask = (1 << 0)			/* continuous conversions */
 		| (1 << 6) | (1 << 5);		/* 9-bit mode */

 	/* configure as specified */
 	status = lm75_read_value(client, LM75_REG_CONF);
 	if (status < 0) {
 		dev_dbg(&client->dev, "Can't read config? %d\n", status);
 		goto exit_free;
 	}
 	data->orig_conf = status;
 	new = status & ~clr_mask;
 	new |= set_mask;
 	if (status != new)
 		lm75_write_value(client, LM75_REG_CONF, new);
 	dev_dbg(&client->dev, "Config %02x\n", new);

 	/* Register sysfs hooks */
 	status = sysfs_create_group(&client->dev.kobj, &lm75_group);
 	if (status)
 		goto exit_free;

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

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

 	return 0;

 exit_remove:
 	sysfs_remove_group(&client->dev.kobj, &lm75_group);
 exit_free:
 	kfree(data);
 	return status;
 }

 static int lm75_remove(struct i2c_client *client)
 {
 	struct lm75_data *data = i2c_get_clientdata(client);

 	hwmon_device_unregister(data->hwmon_dev);
 	sysfs_remove_group(&client->dev.kobj, &lm75_group);
 	lm75_write_value(client, LM75_REG_CONF, data->orig_conf);
 	kfree(data);
 	return 0;
 }

 static const struct i2c_device_id lm75_ids[] = {
 	{ "ds1775", ds1775, },
 	{ "ds75", ds75, },
 	{ "lm75", lm75, },
 	{ "lm75a", lm75a, },
 	{ "max6625", max6625, },
 	{ "max6626", max6626, },
 	{ "mcp980x", mcp980x, },
 	{ "stds75", stds75, },
 	{ "tcn75", tcn75, },
 	{ "tmp100", tmp100, },
 	{ "tmp101", tmp101, },
 	{ "tmp105", tmp105, },
 	{ "tmp175", tmp175, },
 	{ "tmp275", tmp275, },
 	{ "tmp75", tmp75, },
 	{ /* LIST END */ }
 };
 MODULE_DEVICE_TABLE(i2c, lm75_ids);

 /* Return 0 if detection is successful, -ENODEV otherwise */
 static int lm75_detect(struct i2c_client *new_client,
 		       struct i2c_board_info *info)
 {
 	struct i2c_adapter *adapter = new_client->adapter;
 	int i;
 	int cur, conf, hyst, os;

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

 	/* Now, we do the remaining detection. There is no identification-
 	   dedicated register so we have to rely on several tricks:
 	   unused bits, registers cycling over 8-address boundaries,
 	   addresses 0x04-0x07 returning the last read value.
 	   The cycling+unused addresses combination is not tested,
 	   since it would significantly slow the detection down and would
 	   hardly add any value. */

 	/* Unused addresses */
 	cur = i2c_smbus_read_word_data(new_client, 0);
 	conf = i2c_smbus_read_byte_data(new_client, 1);
 	hyst = i2c_smbus_read_word_data(new_client, 2);
 	if (i2c_smbus_read_word_data(new_client, 4) != hyst
 	 || i2c_smbus_read_word_data(new_client, 5) != hyst
 	 || i2c_smbus_read_word_data(new_client, 6) != hyst
 	 || i2c_smbus_read_word_data(new_client, 7) != hyst)
 		return -ENODEV;
 	os = i2c_smbus_read_word_data(new_client, 3);
 	if (i2c_smbus_read_word_data(new_client, 4) != os
 	 || i2c_smbus_read_word_data(new_client, 5) != os
 	 || i2c_smbus_read_word_data(new_client, 6) != os
 	 || i2c_smbus_read_word_data(new_client, 7) != os)
 		return -ENODEV;

 	/* Unused bits */
 	if (conf & 0xe0)
 		return -ENODEV;

 	/* Addresses cycling */
 	for (i = 8; i < 0xff; i += 8) {
 		if (i2c_smbus_read_byte_data(new_client, i + 1) != conf
 		 || i2c_smbus_read_word_data(new_client, i + 2) != hyst
 		 || i2c_smbus_read_word_data(new_client, i + 3) != os)
 			return -ENODEV;
 	}

 	strlcpy(info->type, "lm75", I2C_NAME_SIZE);

 	return 0;
 }

 #ifdef CONFIG_PM
 static int lm75_suspend(struct device *dev)
 {
 	int status;
 	struct i2c_client *client = to_i2c_client(dev);
 	status = lm75_read_value(client, LM75_REG_CONF);
 	if (status < 0) {
 		dev_dbg(&client->dev, "Can't read config? %d\n", status);
 		return status;
 	}
 	status = status | LM75_SHUTDOWN;
 	lm75_write_value(client, LM75_REG_CONF, status);
 	return 0;
 }

 static int lm75_resume(struct device *dev)
 {
 	int status;
 	struct i2c_client *client = to_i2c_client(dev);
 	status = lm75_read_value(client, LM75_REG_CONF);
 	if (status < 0) {
 		dev_dbg(&client->dev, "Can't read config? %d\n", status);
 		return status;
 	}
 	status = status & ~LM75_SHUTDOWN;
 	lm75_write_value(client, LM75_REG_CONF, status);
 	return 0;
 }

 static const struct dev_pm_ops lm75_dev_pm_ops = {
 	.suspend	= lm75_suspend,
 	.resume		= lm75_resume,
 };
 #define LM75_DEV_PM_OPS (&lm75_dev_pm_ops)
 #else
 #define LM75_DEV_PM_OPS NULL
 #endif /* CONFIG_PM */

 static struct i2c_driver lm75_driver = {
 	.class		= I2C_CLASS_HWMON,
 	.driver = {
 		.name	= "lm75",
 		.pm	= LM75_DEV_PM_OPS,
 	},
 	.probe		= lm75_probe,
 	.remove		= lm75_remove,
 	.id_table	= lm75_ids,
 	.detect		= lm75_detect,
 	.address_list	= normal_i2c,
 };

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

 /* register access */

 /* All registers are word-sized, except for the configuration register.
    LM75 uses a high-byte first convention, which is exactly opposite to
    the SMBus standard. */
 static int lm75_read_value(struct i2c_client *client, u8 reg)
 {
 	int value;

 	if (reg == LM75_REG_CONF)
 		return i2c_smbus_read_byte_data(client, reg);

 	value = i2c_smbus_read_word_data(client, reg);
 	return (value < 0) ? value : swab16(value);
 }

 static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value)
 {
 	if (reg == LM75_REG_CONF)
 		return i2c_smbus_write_byte_data(client, reg, value);
 	else
 		return i2c_smbus_write_word_data(client, reg, swab16(value));
 }

 static struct lm75_data *lm75_update_device(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct lm75_data *data = i2c_get_clientdata(client);

 	mutex_lock(&data->update_lock);

 	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
 	    || !data->valid) {
 		int i;
 		dev_dbg(&client->dev, "Starting lm75 update\n");

 		for (i = 0; i < ARRAY_SIZE(data->temp); i++) {
 			int status;

 			status = lm75_read_value(client, LM75_REG_TEMP[i]);
 			if (status < 0)
 				dev_dbg(&client->dev, "reg %d, err %d\n",
 						LM75_REG_TEMP[i], status);
 			else
 				data->temp[i] = status;
 		}
 		data->last_updated = jiffies;
 		data->valid = 1;
 	}

 	mutex_unlock(&data->update_lock);

 	return data;
 }

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

 /* module glue */

 static int __init sensors_lm75_init(void)
 {
 	return i2c_add_driver(&lm75_driver);
 }

 static void __exit sensors_lm75_exit(void)
 {
 	i2c_del_driver(&lm75_driver);
 }

 MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>");
 MODULE_DESCRIPTION("LM75 driver");
 MODULE_LICENSE("GPL");

 module_init(sensors_lm75_init);
 module_exit(sensors_lm75_exit);
	/*
	lm75.c - Part of lm_sensors, Linux kernel modules for hardware
	monitoring
	Copyright (c) 1998, 1999 Frodo Looijaard <frodol@dds.nl>

	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 "lm75.h"


	/*
	* This driver handles the LM75 and compatible digital temperature sensors.
	*/

	enum lm75_type { /* keep sorted in alphabetical order */
	ds1775,
	ds75,
	lm75,
	lm75a,
	max6625,
	max6626,
	mcp980x,
	stds75,
	tcn75,
	tmp100,
	tmp101,
	tmp105,
	tmp175,
	tmp275,
	tmp75,
	};

	/* Addresses scanned */
	static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
	0x4d, 0x4e, 0x4f, I2C_CLIENT_END };


	/* The LM75 registers */
	#define LM75_REG_CONF 0x01
	static const u8 LM75_REG_TEMP[3] = {
	0x00, /* input */
	0x03, /* max */
	0x02, /* hyst */
	};

	/* Each client has this additional data */
	struct lm75_data {
	struct device *hwmon_dev;
	struct mutex update_lock;
	u8 orig_conf;
	char valid; /* !=0 if registers are valid */
	unsigned long last_updated; /* In jiffies */
	u16 temp[3]; /* Register values,
	0 = input
	1 = max
	2 = hyst */
	};

	static int lm75_read_value(struct i2c_client *client, u8 reg);
	static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value);
	static struct lm75_data lm75_update_device(struct device dev);


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

	/* sysfs attributes for hwmon */

	static ssize_t show_temp(struct device dev, struct device_attribute da,
	char *buf)
	{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
	struct lm75_data *data = lm75_update_device(dev);
	return sprintf(buf, "%d\n",
	LM75_TEMP_FROM_REG(data->temp[attr->index]));
	}

	static ssize_t 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 lm75_data *data = i2c_get_clientdata(client);
	int nr = attr->index;
	long temp;
	int error;

	error = strict_strtol(buf, 10, &temp);
	if (error)
	return error;

	mutex_lock(&data->update_lock);
	data->temp[nr] = LM75_TEMP_TO_REG(temp);
	lm75_write_value(client, LM75_REG_TEMP[nr], data->temp[nr]);
	mutex_unlock(&data->update_lock);
	return count;
	}

	static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR \| S_IRUGO,
	show_temp, set_temp, 1);
	static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR \| S_IRUGO,
	show_temp, set_temp, 2);
	static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);

	static struct attribute *lm75_attributes[] = {
	&sensor_dev_attr_temp1_input.dev_attr.attr,
	&sensor_dev_attr_temp1_max.dev_attr.attr,
	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,

	NULL
	};

	static const struct attribute_group lm75_group = {
	.attrs = lm75_attributes,
	};

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

	/* device probe and removal */

	static int
	lm75_probe(struct i2c_client client, const struct i2c_device_id id)
	{
	struct lm75_data *data;
	int status;
	u8 set_mask, clr_mask;
	int new;

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

	data = kzalloc(sizeof(struct lm75_data), GFP_KERNEL);
	if (!data)
	return -ENOMEM;

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

	/* Set to LM75 resolution (9 bits, 1/2 degree C) and range.
	* Then tweak to be more precise when appropriate.
	*/
	set_mask = 0;
	clr_mask = (1 << 0) /* continuous conversions */
	\| (1 << 6) \| (1 << 5); /* 9-bit mode */

	/* configure as specified */
	status = lm75_read_value(client, LM75_REG_CONF);
	if (status < 0) {
	dev_dbg(&client->dev, "Can't read config? %d\n", status);
	goto exit_free;
	}
	data->orig_conf = status;
	new = status & ~clr_mask;
	new \|= set_mask;
	if (status != new)
	lm75_write_value(client, LM75_REG_CONF, new);
	dev_dbg(&client->dev, "Config %02x\n", new);

	/* Register sysfs hooks */
	status = sysfs_create_group(&client->dev.kobj, &lm75_group);
	if (status)
	goto exit_free;

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

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

	return 0;

	exit_remove:
	sysfs_remove_group(&client->dev.kobj, &lm75_group);
	exit_free:
	kfree(data);
	return status;
	}

	static int lm75_remove(struct i2c_client *client)
	{
	struct lm75_data *data = i2c_get_clientdata(client);

	hwmon_device_unregister(data->hwmon_dev);
	sysfs_remove_group(&client->dev.kobj, &lm75_group);
	lm75_write_value(client, LM75_REG_CONF, data->orig_conf);
	kfree(data);
	return 0;
	}

	static const struct i2c_device_id lm75_ids[] = {
	{ "ds1775", ds1775, },
	{ "ds75", ds75, },
	{ "lm75", lm75, },
	{ "lm75a", lm75a, },
	{ "max6625", max6625, },
	{ "max6626", max6626, },
	{ "mcp980x", mcp980x, },
	{ "stds75", stds75, },
	{ "tcn75", tcn75, },
	{ "tmp100", tmp100, },
	{ "tmp101", tmp101, },
	{ "tmp105", tmp105, },
	{ "tmp175", tmp175, },
	{ "tmp275", tmp275, },
	{ "tmp75", tmp75, },
	{ /* LIST END */ }
	};
	MODULE_DEVICE_TABLE(i2c, lm75_ids);

	/* Return 0 if detection is successful, -ENODEV otherwise */
	static int lm75_detect(struct i2c_client *new_client,
	struct i2c_board_info *info)
	{
	struct i2c_adapter *adapter = new_client->adapter;
	int i;
	int cur, conf, hyst, os;

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

	/* Now, we do the remaining detection. There is no identification-
	dedicated register so we have to rely on several tricks:
	unused bits, registers cycling over 8-address boundaries,
	addresses 0x04-0x07 returning the last read value.
	The cycling+unused addresses combination is not tested,
	since it would significantly slow the detection down and would
	hardly add any value. */

	/* Unused addresses */
	cur = i2c_smbus_read_word_data(new_client, 0);
	conf = i2c_smbus_read_byte_data(new_client, 1);
	hyst = i2c_smbus_read_word_data(new_client, 2);
	if (i2c_smbus_read_word_data(new_client, 4) != hyst
	\|\| i2c_smbus_read_word_data(new_client, 5) != hyst
	\|\| i2c_smbus_read_word_data(new_client, 6) != hyst
	\|\| i2c_smbus_read_word_data(new_client, 7) != hyst)
	return -ENODEV;
	os = i2c_smbus_read_word_data(new_client, 3);
	if (i2c_smbus_read_word_data(new_client, 4) != os
	\|\| i2c_smbus_read_word_data(new_client, 5) != os
	\|\| i2c_smbus_read_word_data(new_client, 6) != os
	\|\| i2c_smbus_read_word_data(new_client, 7) != os)
	return -ENODEV;

	/* Unused bits */
	if (conf & 0xe0)
	return -ENODEV;

	/* Addresses cycling */
	for (i = 8; i < 0xff; i += 8) {
	if (i2c_smbus_read_byte_data(new_client, i + 1) != conf
	\|\| i2c_smbus_read_word_data(new_client, i + 2) != hyst
	\|\| i2c_smbus_read_word_data(new_client, i + 3) != os)
	return -ENODEV;
	}

	strlcpy(info->type, "lm75", I2C_NAME_SIZE);

	return 0;
	}

	#ifdef CONFIG_PM
	static int lm75_suspend(struct device *dev)
	{
	int status;
	struct i2c_client *client = to_i2c_client(dev);
	status = lm75_read_value(client, LM75_REG_CONF);
	if (status < 0) {
	dev_dbg(&client->dev, "Can't read config? %d\n", status);
	return status;
	}
	status = status \| LM75_SHUTDOWN;
	lm75_write_value(client, LM75_REG_CONF, status);
	return 0;
	}

	static int lm75_resume(struct device *dev)
	{
	int status;
	struct i2c_client *client = to_i2c_client(dev);
	status = lm75_read_value(client, LM75_REG_CONF);
	if (status < 0) {
	dev_dbg(&client->dev, "Can't read config? %d\n", status);
	return status;
	}
	status = status & ~LM75_SHUTDOWN;
	lm75_write_value(client, LM75_REG_CONF, status);
	return 0;
	}

	static const struct dev_pm_ops lm75_dev_pm_ops = {
	.suspend = lm75_suspend,
	.resume = lm75_resume,
	};
	#define LM75_DEV_PM_OPS (&lm75_dev_pm_ops)
	#else
	#define LM75_DEV_PM_OPS NULL
	#endif /* CONFIG_PM */

	static struct i2c_driver lm75_driver = {
	.class = I2C_CLASS_HWMON,
	.driver = {
	.name = "lm75",
	.pm = LM75_DEV_PM_OPS,
	},
	.probe = lm75_probe,
	.remove = lm75_remove,
	.id_table = lm75_ids,
	.detect = lm75_detect,
	.address_list = normal_i2c,
	};

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

	/* register access */

	/* All registers are word-sized, except for the configuration register.
	LM75 uses a high-byte first convention, which is exactly opposite to
	the SMBus standard. */
	static int lm75_read_value(struct i2c_client *client, u8 reg)
	{
	int value;

	if (reg == LM75_REG_CONF)
	return i2c_smbus_read_byte_data(client, reg);

	value = i2c_smbus_read_word_data(client, reg);
	return (value < 0) ? value : swab16(value);
	}

	static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value)
	{
	if (reg == LM75_REG_CONF)
	return i2c_smbus_write_byte_data(client, reg, value);
	else
	return i2c_smbus_write_word_data(client, reg, swab16(value));
	}

	static struct lm75_data lm75_update_device(struct device dev)
	{
	struct i2c_client *client = to_i2c_client(dev);
	struct lm75_data *data = i2c_get_clientdata(client);

	mutex_lock(&data->update_lock);

	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
	\|\| !data->valid) {
	int i;
	dev_dbg(&client->dev, "Starting lm75 update\n");

	for (i = 0; i < ARRAY_SIZE(data->temp); i++) {
	int status;

	status = lm75_read_value(client, LM75_REG_TEMP[i]);
	if (status < 0)
	dev_dbg(&client->dev, "reg %d, err %d\n",
	LM75_REG_TEMP[i], status);
	else
	data->temp[i] = status;
	}
	data->last_updated = jiffies;
	data->valid = 1;
	}

	mutex_unlock(&data->update_lock);

	return data;
	}

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

	/* module glue */

	static int __init sensors_lm75_init(void)
	{
	return i2c_add_driver(&lm75_driver);
	}

	static void __exit sensors_lm75_exit(void)
	{
	i2c_del_driver(&lm75_driver);
	}

	MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>");
	MODULE_DESCRIPTION("LM75 driver");
	MODULE_LICENSE("GPL");

	module_init(sensors_lm75_init);
	module_exit(sensors_lm75_exit);