drivers/hwmon/lm83.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * lm83.c - Part of lm_sensors, Linux kernel modules for hardware
  *          monitoring
  * Copyright (C) 2003-2009  Jean Delvare <jdelvare@suse.de>
  *
  * Heavily inspired from the lm78, lm75 and adm1021 drivers. The LM83 is
  * a sensor chip made by National Semiconductor. It reports up to four
  * temperatures (its own plus up to three external ones) with a 1 deg
  * resolution and a 3-4 deg accuracy. Complete datasheet can be obtained
  * from National's website at:
  *   http://www.national.com/pf/LM/LM83.html
  * Since the datasheet omits to give the chip stepping code, I give it
  * here: 0x03 (at register 0xff).
  *
  * Also supports the LM82 temp sensor, which is basically a stripped down
  * model of the LM83.  Datasheet is here:
  * http://www.national.com/pf/LM/LM82.html
  */

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

 /*
  * Addresses to scan
  * Address is selected using 2 three-level pins, resulting in 9 possible
  * addresses.
  */

 static const unsigned short normal_i2c[] = {
 	0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b, 0x4c, 0x4d, 0x4e, I2C_CLIENT_END };

 enum chips { lm83, lm82 };

 /*
  * The LM83 registers
  * Manufacturer ID is 0x01 for National Semiconductor.
  */

 #define LM83_REG_R_MAN_ID		0xFE
 #define LM83_REG_R_CHIP_ID		0xFF
 #define LM83_REG_R_CONFIG		0x03
 #define LM83_REG_W_CONFIG		0x09
 #define LM83_REG_R_STATUS1		0x02
 #define LM83_REG_R_STATUS2		0x35
 #define LM83_REG_R_LOCAL_TEMP		0x00
 #define LM83_REG_R_LOCAL_HIGH		0x05
 #define LM83_REG_W_LOCAL_HIGH		0x0B
 #define LM83_REG_R_REMOTE1_TEMP		0x30
 #define LM83_REG_R_REMOTE1_HIGH		0x38
 #define LM83_REG_W_REMOTE1_HIGH		0x50
 #define LM83_REG_R_REMOTE2_TEMP		0x01
 #define LM83_REG_R_REMOTE2_HIGH		0x07
 #define LM83_REG_W_REMOTE2_HIGH		0x0D
 #define LM83_REG_R_REMOTE3_TEMP		0x31
 #define LM83_REG_R_REMOTE3_HIGH		0x3A
 #define LM83_REG_W_REMOTE3_HIGH		0x52
 #define LM83_REG_R_TCRIT		0x42
 #define LM83_REG_W_TCRIT		0x5A

 /*
  * Conversions and various macros
  * The LM83 uses signed 8-bit values with LSB = 1 degree Celsius.
  */

 #define TEMP_FROM_REG(val)	((val) * 1000)
 #define TEMP_TO_REG(val)	((val) <= -128000 ? -128 : \
 				 (val) >= 127000 ? 127 : \
 				 (val) < 0 ? ((val) - 500) / 1000 : \
 				 ((val) + 500) / 1000)

 static const u8 LM83_REG_R_TEMP[] = {
 	LM83_REG_R_LOCAL_TEMP,
 	LM83_REG_R_REMOTE1_TEMP,
 	LM83_REG_R_REMOTE2_TEMP,
 	LM83_REG_R_REMOTE3_TEMP,
 	LM83_REG_R_LOCAL_HIGH,
 	LM83_REG_R_REMOTE1_HIGH,
 	LM83_REG_R_REMOTE2_HIGH,
 	LM83_REG_R_REMOTE3_HIGH,
 	LM83_REG_R_TCRIT,
 };

 static const u8 LM83_REG_W_HIGH[] = {
 	LM83_REG_W_LOCAL_HIGH,
 	LM83_REG_W_REMOTE1_HIGH,
 	LM83_REG_W_REMOTE2_HIGH,
 	LM83_REG_W_REMOTE3_HIGH,
 	LM83_REG_W_TCRIT,
 };

 /*
  * Client data (each client gets its own)
  */

 struct lm83_data {
 	struct i2c_client *client;
 	const struct attribute_group *groups[3];
 	struct mutex update_lock;
 	bool valid; /* false until following fields are valid */
 	unsigned long last_updated; /* in jiffies */

 	/* registers values */
 	s8 temp[9];	/* 0..3: input 1-4,
 			   4..7: high limit 1-4,
 			   8   : critical limit */
 	u16 alarms; /* bitvector, combined */
 };

 static struct lm83_data *lm83_update_device(struct device *dev)
 {
 	struct lm83_data *data = dev_get_drvdata(dev);
 	struct i2c_client *client = data->client;

 	mutex_lock(&data->update_lock);

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

 		dev_dbg(&client->dev, "Updating lm83 data.\n");
 		for (nr = 0; nr < 9; nr++) {
 			data->temp[nr] =
 			    i2c_smbus_read_byte_data(client,
 			    LM83_REG_R_TEMP[nr]);
 		}
 		data->alarms =
 		    i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS1)
 		    + (i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS2)
 		    << 8);

 		data->last_updated = jiffies;
 		data->valid = true;
 	}

 	mutex_unlock(&data->update_lock);

 	return data;
 }

 /*
  * Sysfs stuff
  */

 static ssize_t temp_show(struct device *dev, struct device_attribute *devattr,
 			 char *buf)
 {
 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 	struct lm83_data *data = lm83_update_device(dev);
 	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[attr->index]));
 }

 static ssize_t temp_store(struct device *dev,
 			  struct device_attribute *devattr, const char *buf,
 			  size_t count)
 {
 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 	struct lm83_data *data = dev_get_drvdata(dev);
 	struct i2c_client *client = data->client;
 	long val;
 	int nr = attr->index;
 	int err;

 	err = kstrtol(buf, 10, &val);
 	if (err < 0)
 		return err;

 	mutex_lock(&data->update_lock);
 	data->temp[nr] = TEMP_TO_REG(val);
 	i2c_smbus_write_byte_data(client, LM83_REG_W_HIGH[nr - 4],
 				  data->temp[nr]);
 	mutex_unlock(&data->update_lock);
 	return count;
 }

 static ssize_t alarms_show(struct device *dev, struct device_attribute *dummy,
 			   char *buf)
 {
 	struct lm83_data *data = lm83_update_device(dev);
 	return sprintf(buf, "%d\n", data->alarms);
 }

 static ssize_t alarm_show(struct device *dev,
 			  struct device_attribute *devattr, char *buf)
 {
 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 	struct lm83_data *data = lm83_update_device(dev);
 	int bitnr = attr->index;

 	return sprintf(buf, "%d\n", (data->alarms >> bitnr) & 1);
 }

 static SENSOR_DEVICE_ATTR_RO(temp1_input, temp, 0);
 static SENSOR_DEVICE_ATTR_RO(temp2_input, temp, 1);
 static SENSOR_DEVICE_ATTR_RO(temp3_input, temp, 2);
 static SENSOR_DEVICE_ATTR_RO(temp4_input, temp, 3);
 static SENSOR_DEVICE_ATTR_RW(temp1_max, temp, 4);
 static SENSOR_DEVICE_ATTR_RW(temp2_max, temp, 5);
 static SENSOR_DEVICE_ATTR_RW(temp3_max, temp, 6);
 static SENSOR_DEVICE_ATTR_RW(temp4_max, temp, 7);
 static SENSOR_DEVICE_ATTR_RO(temp1_crit, temp, 8);
 static SENSOR_DEVICE_ATTR_RO(temp2_crit, temp, 8);
 static SENSOR_DEVICE_ATTR_RW(temp3_crit, temp, 8);
 static SENSOR_DEVICE_ATTR_RO(temp4_crit, temp, 8);

 /* Individual alarm files */
 static SENSOR_DEVICE_ATTR_RO(temp1_crit_alarm, alarm, 0);
 static SENSOR_DEVICE_ATTR_RO(temp3_crit_alarm, alarm, 1);
 static SENSOR_DEVICE_ATTR_RO(temp3_fault, alarm, 2);
 static SENSOR_DEVICE_ATTR_RO(temp3_max_alarm, alarm, 4);
 static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, alarm, 6);
 static SENSOR_DEVICE_ATTR_RO(temp2_crit_alarm, alarm, 8);
 static SENSOR_DEVICE_ATTR_RO(temp4_crit_alarm, alarm, 9);
 static SENSOR_DEVICE_ATTR_RO(temp4_fault, alarm, 10);
 static SENSOR_DEVICE_ATTR_RO(temp4_max_alarm, alarm, 12);
 static SENSOR_DEVICE_ATTR_RO(temp2_fault, alarm, 13);
 static SENSOR_DEVICE_ATTR_RO(temp2_max_alarm, alarm, 15);
 /* Raw alarm file for compatibility */
 static DEVICE_ATTR_RO(alarms);

 static struct attribute *lm83_attributes[] = {
 	&sensor_dev_attr_temp1_input.dev_attr.attr,
 	&sensor_dev_attr_temp3_input.dev_attr.attr,
 	&sensor_dev_attr_temp1_max.dev_attr.attr,
 	&sensor_dev_attr_temp3_max.dev_attr.attr,
 	&sensor_dev_attr_temp1_crit.dev_attr.attr,
 	&sensor_dev_attr_temp3_crit.dev_attr.attr,

 	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
 	&sensor_dev_attr_temp3_crit_alarm.dev_attr.attr,
 	&sensor_dev_attr_temp3_fault.dev_attr.attr,
 	&sensor_dev_attr_temp3_max_alarm.dev_attr.attr,
 	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
 	&dev_attr_alarms.attr,
 	NULL
 };

 static const struct attribute_group lm83_group = {
 	.attrs = lm83_attributes,
 };

 static struct attribute *lm83_attributes_opt[] = {
 	&sensor_dev_attr_temp2_input.dev_attr.attr,
 	&sensor_dev_attr_temp4_input.dev_attr.attr,
 	&sensor_dev_attr_temp2_max.dev_attr.attr,
 	&sensor_dev_attr_temp4_max.dev_attr.attr,
 	&sensor_dev_attr_temp2_crit.dev_attr.attr,
 	&sensor_dev_attr_temp4_crit.dev_attr.attr,

 	&sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
 	&sensor_dev_attr_temp4_crit_alarm.dev_attr.attr,
 	&sensor_dev_attr_temp4_fault.dev_attr.attr,
 	&sensor_dev_attr_temp4_max_alarm.dev_attr.attr,
 	&sensor_dev_attr_temp2_fault.dev_attr.attr,
 	&sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
 	NULL
 };

 static const struct attribute_group lm83_group_opt = {
 	.attrs = lm83_attributes_opt,
 };

 /*
  * Real code
  */

 /* Return 0 if detection is successful, -ENODEV otherwise */
 static int lm83_detect(struct i2c_client *new_client,
 		       struct i2c_board_info *info)
 {
 	struct i2c_adapter *adapter = new_client->adapter;
 	const char *name;
 	u8 man_id, chip_id;

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

 	/* Detection */
 	if ((i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS1) & 0xA8) ||
 	    (i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS2) & 0x48) ||
 	    (i2c_smbus_read_byte_data(new_client, LM83_REG_R_CONFIG) & 0x41)) {
 		dev_dbg(&adapter->dev, "LM83 detection failed at 0x%02x\n",
 			new_client->addr);
 		return -ENODEV;
 	}

 	/* Identification */
 	man_id = i2c_smbus_read_byte_data(new_client, LM83_REG_R_MAN_ID);
 	if (man_id != 0x01)	/* National Semiconductor */
 		return -ENODEV;

 	chip_id = i2c_smbus_read_byte_data(new_client, LM83_REG_R_CHIP_ID);
 	switch (chip_id) {
 	case 0x03:
 		name = "lm83";
 		break;
 	case 0x01:
 		name = "lm82";
 		break;
 	default:
 		/* identification failed */
 		dev_info(&adapter->dev,
 			 "Unsupported chip (man_id=0x%02X, chip_id=0x%02X)\n",
 			 man_id, chip_id);
 		return -ENODEV;
 	}

 	strlcpy(info->type, name, I2C_NAME_SIZE);

 	return 0;
 }

 static const struct i2c_device_id lm83_id[];

 static int lm83_probe(struct i2c_client *new_client)
 {
 	struct device *hwmon_dev;
 	struct lm83_data *data;

 	data = devm_kzalloc(&new_client->dev, sizeof(struct lm83_data),
 			    GFP_KERNEL);
 	if (!data)
 		return -ENOMEM;

 	data->client = new_client;
 	mutex_init(&data->update_lock);

 	/*
 	 * Register sysfs hooks
 	 * The LM82 can only monitor one external diode which is
 	 * at the same register as the LM83 temp3 entry - so we
 	 * declare 1 and 3 common, and then 2 and 4 only for the LM83.
 	 */
 	data->groups[0] = &lm83_group;
 	if (i2c_match_id(lm83_id, new_client)->driver_data == lm83)
 		data->groups[1] = &lm83_group_opt;

 	hwmon_dev = devm_hwmon_device_register_with_groups(&new_client->dev,
 							   new_client->name,
 							   data, data->groups);
 	return PTR_ERR_OR_ZERO(hwmon_dev);
 }

 /*
  * Driver data (common to all clients)
  */

 static const struct i2c_device_id lm83_id[] = {
 	{ "lm83", lm83 },
 	{ "lm82", lm82 },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, lm83_id);

 static struct i2c_driver lm83_driver = {
 	.class		= I2C_CLASS_HWMON,
 	.driver = {
 		.name	= "lm83",
 	},
 	.probe_new	= lm83_probe,
 	.id_table	= lm83_id,
 	.detect		= lm83_detect,
 	.address_list	= normal_i2c,
 };

 module_i2c_driver(lm83_driver);

 MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>");
 MODULE_DESCRIPTION("LM83 driver");
 MODULE_LICENSE("GPL");
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* lm83.c - Part of lm_sensors, Linux kernel modules for hardware
	* monitoring
	* Copyright (C) 2003-2009 Jean Delvare <jdelvare@suse.de>
	*
	* Heavily inspired from the lm78, lm75 and adm1021 drivers. The LM83 is
	* a sensor chip made by National Semiconductor. It reports up to four
	* temperatures (its own plus up to three external ones) with a 1 deg
	* resolution and a 3-4 deg accuracy. Complete datasheet can be obtained
	* from National's website at:
	* http://www.national.com/pf/LM/LM83.html
	* Since the datasheet omits to give the chip stepping code, I give it
	* here: 0x03 (at register 0xff).
	*
	* Also supports the LM82 temp sensor, which is basically a stripped down
	* model of the LM83. Datasheet is here:
	* http://www.national.com/pf/LM/LM82.html
	*/

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

	/*
	* Addresses to scan
	* Address is selected using 2 three-level pins, resulting in 9 possible
	* addresses.
	*/

	static const unsigned short normal_i2c[] = {
	0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b, 0x4c, 0x4d, 0x4e, I2C_CLIENT_END };

	enum chips { lm83, lm82 };

	/*
	* The LM83 registers
	* Manufacturer ID is 0x01 for National Semiconductor.
	*/

	#define LM83_REG_R_MAN_ID 0xFE
	#define LM83_REG_R_CHIP_ID 0xFF
	#define LM83_REG_R_CONFIG 0x03
	#define LM83_REG_W_CONFIG 0x09
	#define LM83_REG_R_STATUS1 0x02
	#define LM83_REG_R_STATUS2 0x35
	#define LM83_REG_R_LOCAL_TEMP 0x00
	#define LM83_REG_R_LOCAL_HIGH 0x05
	#define LM83_REG_W_LOCAL_HIGH 0x0B
	#define LM83_REG_R_REMOTE1_TEMP 0x30
	#define LM83_REG_R_REMOTE1_HIGH 0x38
	#define LM83_REG_W_REMOTE1_HIGH 0x50
	#define LM83_REG_R_REMOTE2_TEMP 0x01
	#define LM83_REG_R_REMOTE2_HIGH 0x07
	#define LM83_REG_W_REMOTE2_HIGH 0x0D
	#define LM83_REG_R_REMOTE3_TEMP 0x31
	#define LM83_REG_R_REMOTE3_HIGH 0x3A
	#define LM83_REG_W_REMOTE3_HIGH 0x52
	#define LM83_REG_R_TCRIT 0x42
	#define LM83_REG_W_TCRIT 0x5A

	/*
	* Conversions and various macros
	* The LM83 uses signed 8-bit values with LSB = 1 degree Celsius.
	*/

	#define TEMP_FROM_REG(val) ((val) * 1000)
	#define TEMP_TO_REG(val) ((val) <= -128000 ? -128 : \
	(val) >= 127000 ? 127 : \
	(val) < 0 ? ((val) - 500) / 1000 : \
	((val) + 500) / 1000)

	static const u8 LM83_REG_R_TEMP[] = {
	LM83_REG_R_LOCAL_TEMP,
	LM83_REG_R_REMOTE1_TEMP,
	LM83_REG_R_REMOTE2_TEMP,
	LM83_REG_R_REMOTE3_TEMP,
	LM83_REG_R_LOCAL_HIGH,
	LM83_REG_R_REMOTE1_HIGH,
	LM83_REG_R_REMOTE2_HIGH,
	LM83_REG_R_REMOTE3_HIGH,
	LM83_REG_R_TCRIT,
	};

	static const u8 LM83_REG_W_HIGH[] = {
	LM83_REG_W_LOCAL_HIGH,
	LM83_REG_W_REMOTE1_HIGH,
	LM83_REG_W_REMOTE2_HIGH,
	LM83_REG_W_REMOTE3_HIGH,
	LM83_REG_W_TCRIT,
	};

	/*
	* Client data (each client gets its own)
	*/

	struct lm83_data {
	struct i2c_client *client;
	const struct attribute_group *groups[3];
	struct mutex update_lock;
	bool valid; /* false until following fields are valid */
	unsigned long last_updated; /* in jiffies */

	/* registers values */
	s8 temp[9]; /* 0..3: input 1-4,
	4..7: high limit 1-4,
	8 : critical limit */
	u16 alarms; /* bitvector, combined */
	};

	static struct lm83_data lm83_update_device(struct device dev)
	{
	struct lm83_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;

	mutex_lock(&data->update_lock);

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

	dev_dbg(&client->dev, "Updating lm83 data.\n");
	for (nr = 0; nr < 9; nr++) {
	data->temp[nr] =
	i2c_smbus_read_byte_data(client,
	LM83_REG_R_TEMP[nr]);
	}
	data->alarms =
	i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS1)
	+ (i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS2)
	<< 8);

	data->last_updated = jiffies;
	data->valid = true;
	}

	mutex_unlock(&data->update_lock);

	return data;
	}

	/*
	* Sysfs stuff
	*/

	static ssize_t temp_show(struct device dev, struct device_attribute devattr,
	char *buf)
	{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct lm83_data *data = lm83_update_device(dev);
	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[attr->index]));
	}

	static ssize_t temp_store(struct device *dev,
	struct device_attribute devattr, const char buf,
	size_t count)
	{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct lm83_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;
	long val;
	int nr = attr->index;
	int err;

	err = kstrtol(buf, 10, &val);
	if (err < 0)
	return err;

	mutex_lock(&data->update_lock);
	data->temp[nr] = TEMP_TO_REG(val);
	i2c_smbus_write_byte_data(client, LM83_REG_W_HIGH[nr - 4],
	data->temp[nr]);
	mutex_unlock(&data->update_lock);
	return count;
	}

	static ssize_t alarms_show(struct device dev, struct device_attribute dummy,
	char *buf)
	{
	struct lm83_data *data = lm83_update_device(dev);
	return sprintf(buf, "%d\n", data->alarms);
	}

	static ssize_t alarm_show(struct device *dev,
	struct device_attribute devattr, char buf)
	{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct lm83_data *data = lm83_update_device(dev);
	int bitnr = attr->index;

	return sprintf(buf, "%d\n", (data->alarms >> bitnr) & 1);
	}

	static SENSOR_DEVICE_ATTR_RO(temp1_input, temp, 0);
	static SENSOR_DEVICE_ATTR_RO(temp2_input, temp, 1);
	static SENSOR_DEVICE_ATTR_RO(temp3_input, temp, 2);
	static SENSOR_DEVICE_ATTR_RO(temp4_input, temp, 3);
	static SENSOR_DEVICE_ATTR_RW(temp1_max, temp, 4);
	static SENSOR_DEVICE_ATTR_RW(temp2_max, temp, 5);
	static SENSOR_DEVICE_ATTR_RW(temp3_max, temp, 6);
	static SENSOR_DEVICE_ATTR_RW(temp4_max, temp, 7);
	static SENSOR_DEVICE_ATTR_RO(temp1_crit, temp, 8);
	static SENSOR_DEVICE_ATTR_RO(temp2_crit, temp, 8);
	static SENSOR_DEVICE_ATTR_RW(temp3_crit, temp, 8);
	static SENSOR_DEVICE_ATTR_RO(temp4_crit, temp, 8);

	/* Individual alarm files */
	static SENSOR_DEVICE_ATTR_RO(temp1_crit_alarm, alarm, 0);
	static SENSOR_DEVICE_ATTR_RO(temp3_crit_alarm, alarm, 1);
	static SENSOR_DEVICE_ATTR_RO(temp3_fault, alarm, 2);
	static SENSOR_DEVICE_ATTR_RO(temp3_max_alarm, alarm, 4);
	static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, alarm, 6);
	static SENSOR_DEVICE_ATTR_RO(temp2_crit_alarm, alarm, 8);
	static SENSOR_DEVICE_ATTR_RO(temp4_crit_alarm, alarm, 9);
	static SENSOR_DEVICE_ATTR_RO(temp4_fault, alarm, 10);
	static SENSOR_DEVICE_ATTR_RO(temp4_max_alarm, alarm, 12);
	static SENSOR_DEVICE_ATTR_RO(temp2_fault, alarm, 13);
	static SENSOR_DEVICE_ATTR_RO(temp2_max_alarm, alarm, 15);
	/* Raw alarm file for compatibility */
	static DEVICE_ATTR_RO(alarms);

	static struct attribute *lm83_attributes[] = {
	&sensor_dev_attr_temp1_input.dev_attr.attr,
	&sensor_dev_attr_temp3_input.dev_attr.attr,
	&sensor_dev_attr_temp1_max.dev_attr.attr,
	&sensor_dev_attr_temp3_max.dev_attr.attr,
	&sensor_dev_attr_temp1_crit.dev_attr.attr,
	&sensor_dev_attr_temp3_crit.dev_attr.attr,

	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
	&sensor_dev_attr_temp3_crit_alarm.dev_attr.attr,
	&sensor_dev_attr_temp3_fault.dev_attr.attr,
	&sensor_dev_attr_temp3_max_alarm.dev_attr.attr,
	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
	&dev_attr_alarms.attr,
	NULL
	};

	static const struct attribute_group lm83_group = {
	.attrs = lm83_attributes,
	};

	static struct attribute *lm83_attributes_opt[] = {
	&sensor_dev_attr_temp2_input.dev_attr.attr,
	&sensor_dev_attr_temp4_input.dev_attr.attr,
	&sensor_dev_attr_temp2_max.dev_attr.attr,
	&sensor_dev_attr_temp4_max.dev_attr.attr,
	&sensor_dev_attr_temp2_crit.dev_attr.attr,
	&sensor_dev_attr_temp4_crit.dev_attr.attr,

	&sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
	&sensor_dev_attr_temp4_crit_alarm.dev_attr.attr,
	&sensor_dev_attr_temp4_fault.dev_attr.attr,
	&sensor_dev_attr_temp4_max_alarm.dev_attr.attr,
	&sensor_dev_attr_temp2_fault.dev_attr.attr,
	&sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
	NULL
	};

	static const struct attribute_group lm83_group_opt = {
	.attrs = lm83_attributes_opt,
	};

	/*
	* Real code
	*/

	/* Return 0 if detection is successful, -ENODEV otherwise */
	static int lm83_detect(struct i2c_client *new_client,
	struct i2c_board_info *info)
	{
	struct i2c_adapter *adapter = new_client->adapter;
	const char *name;
	u8 man_id, chip_id;

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

	/* Detection */
	if ((i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS1) & 0xA8) \|\|
	(i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS2) & 0x48) \|\|
	(i2c_smbus_read_byte_data(new_client, LM83_REG_R_CONFIG) & 0x41)) {
	dev_dbg(&adapter->dev, "LM83 detection failed at 0x%02x\n",
	new_client->addr);
	return -ENODEV;
	}

	/* Identification */
	man_id = i2c_smbus_read_byte_data(new_client, LM83_REG_R_MAN_ID);
	if (man_id != 0x01) /* National Semiconductor */
	return -ENODEV;

	chip_id = i2c_smbus_read_byte_data(new_client, LM83_REG_R_CHIP_ID);
	switch (chip_id) {
	case 0x03:
	name = "lm83";
	break;
	case 0x01:
	name = "lm82";
	break;
	default:
	/* identification failed */
	dev_info(&adapter->dev,
	"Unsupported chip (man_id=0x%02X, chip_id=0x%02X)\n",
	man_id, chip_id);
	return -ENODEV;
	}

	strlcpy(info->type, name, I2C_NAME_SIZE);

	return 0;
	}

	static const struct i2c_device_id lm83_id[];

	static int lm83_probe(struct i2c_client *new_client)
	{
	struct device *hwmon_dev;
	struct lm83_data *data;

	data = devm_kzalloc(&new_client->dev, sizeof(struct lm83_data),
	GFP_KERNEL);
	if (!data)
	return -ENOMEM;

	data->client = new_client;
	mutex_init(&data->update_lock);

	/*
	* Register sysfs hooks
	* The LM82 can only monitor one external diode which is
	* at the same register as the LM83 temp3 entry - so we
	* declare 1 and 3 common, and then 2 and 4 only for the LM83.
	*/
	data->groups[0] = &lm83_group;
	if (i2c_match_id(lm83_id, new_client)->driver_data == lm83)
	data->groups[1] = &lm83_group_opt;

	hwmon_dev = devm_hwmon_device_register_with_groups(&new_client->dev,
	new_client->name,
	data, data->groups);
	return PTR_ERR_OR_ZERO(hwmon_dev);
	}

	/*
	* Driver data (common to all clients)
	*/

	static const struct i2c_device_id lm83_id[] = {
	{ "lm83", lm83 },
	{ "lm82", lm82 },
	{ }
	};
	MODULE_DEVICE_TABLE(i2c, lm83_id);

	static struct i2c_driver lm83_driver = {
	.class = I2C_CLASS_HWMON,
	.driver = {
	.name = "lm83",
	},
	.probe_new = lm83_probe,
	.id_table = lm83_id,
	.detect = lm83_detect,
	.address_list = normal_i2c,
	};

	module_i2c_driver(lm83_driver);

	MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>");
	MODULE_DESCRIPTION("LM83 driver");
	MODULE_LICENSE("GPL");