drivers/hwmon/adm1021.c - third_party/kernel - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * adm1021.c - Part of lm_sensors, Linux kernel modules for hardware
  *	       monitoring
  * Copyright (c) 1998, 1999  Frodo Looijaard <frodol@dds.nl> and
  *			     Philip Edelbrock <phil@netroedge.com>
  */

 #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>


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

 enum chips {
 	adm1021, adm1023, max1617, max1617a, thmc10, lm84, gl523sm, mc1066 };

 /* adm1021 constants specified below */

 /* The adm1021 registers */
 /* Read-only */
 /* For nr in 0-1 */
 #define ADM1021_REG_TEMP(nr)		(nr)
 #define ADM1021_REG_STATUS		0x02
 /* 0x41 = AD, 0x49 = TI, 0x4D = Maxim, 0x23 = Genesys , 0x54 = Onsemi */
 #define ADM1021_REG_MAN_ID		0xFE
 /* ADM1021 = 0x0X, ADM1023 = 0x3X */
 #define ADM1021_REG_DEV_ID		0xFF
 /* These use different addresses for reading/writing */
 #define ADM1021_REG_CONFIG_R		0x03
 #define ADM1021_REG_CONFIG_W		0x09
 #define ADM1021_REG_CONV_RATE_R		0x04
 #define ADM1021_REG_CONV_RATE_W		0x0A
 /* These are for the ADM1023's additional precision on the remote temp sensor */
 #define ADM1023_REG_REM_TEMP_PREC	0x10
 #define ADM1023_REG_REM_OFFSET		0x11
 #define ADM1023_REG_REM_OFFSET_PREC	0x12
 #define ADM1023_REG_REM_TOS_PREC	0x13
 #define ADM1023_REG_REM_THYST_PREC	0x14
 /* limits */
 /* For nr in 0-1 */
 #define ADM1021_REG_TOS_R(nr)		(0x05 + 2 * (nr))
 #define ADM1021_REG_TOS_W(nr)		(0x0B + 2 * (nr))
 #define ADM1021_REG_THYST_R(nr)		(0x06 + 2 * (nr))
 #define ADM1021_REG_THYST_W(nr)		(0x0C + 2 * (nr))
 /* write-only */
 #define ADM1021_REG_ONESHOT		0x0F

 /* Initial values */

 /*
  * Note: Even though I left the low and high limits named os and hyst,
  * they don't quite work like a thermostat the way the LM75 does.  I.e.,
  * a lower temp than THYST actually triggers an alarm instead of
  * clearing it.  Weird, ey?   --Phil
  */

 /* Each client has this additional data */
 struct adm1021_data {
 	struct i2c_client *client;
 	enum chips type;

 	const struct attribute_group *groups[3];

 	struct mutex update_lock;
 	bool valid;		/* true if following fields are valid */
 	char low_power;		/* !=0 if device in low power mode */
 	unsigned long last_updated;	/* In jiffies */

 	int temp_max[2];		/* Register values */
 	int temp_min[2];
 	int temp[2];
 	u8 alarms;
 	/* Special values for ADM1023 only */
 	u8 remote_temp_offset;
 	u8 remote_temp_offset_prec;
 };

 /* (amalysh) read only mode, otherwise any limit's writing confuse BIOS */
 static bool read_only;

 static struct adm1021_data *adm1021_update_device(struct device *dev)
 {
 	struct adm1021_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 + HZ / 2)
 	    || !data->valid) {
 		int i;

 		dev_dbg(dev, "Starting adm1021 update\n");

 		for (i = 0; i < 2; i++) {
 			data->temp[i] = 1000 *
 				(s8) i2c_smbus_read_byte_data(
 					client, ADM1021_REG_TEMP(i));
 			data->temp_max[i] = 1000 *
 				(s8) i2c_smbus_read_byte_data(
 					client, ADM1021_REG_TOS_R(i));
 			if (data->type != lm84) {
 				data->temp_min[i] = 1000 *
 				  (s8) i2c_smbus_read_byte_data(client,
 							ADM1021_REG_THYST_R(i));
 			}
 		}
 		data->alarms = i2c_smbus_read_byte_data(client,
 						ADM1021_REG_STATUS) & 0x7c;
 		if (data->type == adm1023) {
 			/*
 			 * The ADM1023 provides 3 extra bits of precision for
 			 * the remote sensor in extra registers.
 			 */
 			data->temp[1] += 125 * (i2c_smbus_read_byte_data(
 				client, ADM1023_REG_REM_TEMP_PREC) >> 5);
 			data->temp_max[1] += 125 * (i2c_smbus_read_byte_data(
 				client, ADM1023_REG_REM_TOS_PREC) >> 5);
 			data->temp_min[1] += 125 * (i2c_smbus_read_byte_data(
 				client, ADM1023_REG_REM_THYST_PREC) >> 5);
 			data->remote_temp_offset =
 				i2c_smbus_read_byte_data(client,
 						ADM1023_REG_REM_OFFSET);
 			data->remote_temp_offset_prec =
 				i2c_smbus_read_byte_data(client,
 						ADM1023_REG_REM_OFFSET_PREC);
 		}
 		data->last_updated = jiffies;
 		data->valid = true;
 	}

 	mutex_unlock(&data->update_lock);

 	return data;
 }

 static ssize_t temp_show(struct device *dev, struct device_attribute *devattr,
 			 char *buf)
 {
 	int index = to_sensor_dev_attr(devattr)->index;
 	struct adm1021_data *data = adm1021_update_device(dev);

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

 static ssize_t temp_max_show(struct device *dev,
 			     struct device_attribute *devattr, char *buf)
 {
 	int index = to_sensor_dev_attr(devattr)->index;
 	struct adm1021_data *data = adm1021_update_device(dev);

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

 static ssize_t temp_min_show(struct device *dev,
 			     struct device_attribute *devattr, char *buf)
 {
 	int index = to_sensor_dev_attr(devattr)->index;
 	struct adm1021_data *data = adm1021_update_device(dev);

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

 static ssize_t alarm_show(struct device *dev, struct device_attribute *attr,
 			  char *buf)
 {
 	int index = to_sensor_dev_attr(attr)->index;
 	struct adm1021_data *data = adm1021_update_device(dev);
 	return sprintf(buf, "%u\n", (data->alarms >> index) & 1);
 }

 static ssize_t alarms_show(struct device *dev,
 			   struct device_attribute *attr,
 			   char *buf)
 {
 	struct adm1021_data *data = adm1021_update_device(dev);
 	return sprintf(buf, "%u\n", data->alarms);
 }

 static ssize_t temp_max_store(struct device *dev,
 			      struct device_attribute *devattr,
 			      const char *buf, size_t count)
 {
 	int index = to_sensor_dev_attr(devattr)->index;
 	struct adm1021_data *data = dev_get_drvdata(dev);
 	struct i2c_client *client = data->client;
 	long temp;
 	int reg_val, err;

 	err = kstrtol(buf, 10, &temp);
 	if (err)
 		return err;
 	temp /= 1000;

 	mutex_lock(&data->update_lock);
 	reg_val = clamp_val(temp, -128, 127);
 	data->temp_max[index] = reg_val * 1000;
 	if (!read_only)
 		i2c_smbus_write_byte_data(client, ADM1021_REG_TOS_W(index),
 					  reg_val);
 	mutex_unlock(&data->update_lock);

 	return count;
 }

 static ssize_t temp_min_store(struct device *dev,
 			      struct device_attribute *devattr,
 			      const char *buf, size_t count)
 {
 	int index = to_sensor_dev_attr(devattr)->index;
 	struct adm1021_data *data = dev_get_drvdata(dev);
 	struct i2c_client *client = data->client;
 	long temp;
 	int reg_val, err;

 	err = kstrtol(buf, 10, &temp);
 	if (err)
 		return err;
 	temp /= 1000;

 	mutex_lock(&data->update_lock);
 	reg_val = clamp_val(temp, -128, 127);
 	data->temp_min[index] = reg_val * 1000;
 	if (!read_only)
 		i2c_smbus_write_byte_data(client, ADM1021_REG_THYST_W(index),
 					  reg_val);
 	mutex_unlock(&data->update_lock);

 	return count;
 }

 static ssize_t low_power_show(struct device *dev,
 			      struct device_attribute *devattr, char *buf)
 {
 	struct adm1021_data *data = adm1021_update_device(dev);
 	return sprintf(buf, "%d\n", data->low_power);
 }

 static ssize_t low_power_store(struct device *dev,
 			       struct device_attribute *devattr,
 			       const char *buf, size_t count)
 {
 	struct adm1021_data *data = dev_get_drvdata(dev);
 	struct i2c_client *client = data->client;
 	char low_power;
 	unsigned long val;
 	int err;

 	err = kstrtoul(buf, 10, &val);
 	if (err)
 		return err;
 	low_power = val != 0;

 	mutex_lock(&data->update_lock);
 	if (low_power != data->low_power) {
 		int config = i2c_smbus_read_byte_data(
 			client, ADM1021_REG_CONFIG_R);
 		data->low_power = low_power;
 		i2c_smbus_write_byte_data(client, ADM1021_REG_CONFIG_W,
 			(config & 0xBF) | (low_power << 6));
 	}
 	mutex_unlock(&data->update_lock);

 	return count;
 }


 static SENSOR_DEVICE_ATTR_RO(temp1_input, temp, 0);
 static SENSOR_DEVICE_ATTR_RW(temp1_max, temp_max, 0);
 static SENSOR_DEVICE_ATTR_RW(temp1_min, temp_min, 0);
 static SENSOR_DEVICE_ATTR_RO(temp2_input, temp, 1);
 static SENSOR_DEVICE_ATTR_RW(temp2_max, temp_max, 1);
 static SENSOR_DEVICE_ATTR_RW(temp2_min, temp_min, 1);
 static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, alarm, 6);
 static SENSOR_DEVICE_ATTR_RO(temp1_min_alarm, alarm, 5);
 static SENSOR_DEVICE_ATTR_RO(temp2_max_alarm, alarm, 4);
 static SENSOR_DEVICE_ATTR_RO(temp2_min_alarm, alarm, 3);
 static SENSOR_DEVICE_ATTR_RO(temp2_fault, alarm, 2);

 static DEVICE_ATTR_RO(alarms);
 static DEVICE_ATTR_RW(low_power);

 static struct attribute *adm1021_attributes[] = {
 	&sensor_dev_attr_temp1_max.dev_attr.attr,
 	&sensor_dev_attr_temp1_input.dev_attr.attr,
 	&sensor_dev_attr_temp2_max.dev_attr.attr,
 	&sensor_dev_attr_temp2_input.dev_attr.attr,
 	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
 	&sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
 	&sensor_dev_attr_temp2_fault.dev_attr.attr,
 	&dev_attr_alarms.attr,
 	&dev_attr_low_power.attr,
 	NULL
 };

 static const struct attribute_group adm1021_group = {
 	.attrs = adm1021_attributes,
 };

 static struct attribute *adm1021_min_attributes[] = {
 	&sensor_dev_attr_temp1_min.dev_attr.attr,
 	&sensor_dev_attr_temp2_min.dev_attr.attr,
 	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
 	&sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
 	NULL
 };

 static const struct attribute_group adm1021_min_group = {
 	.attrs = adm1021_min_attributes,
 };

 /* Return 0 if detection is successful, -ENODEV otherwise */
 static int adm1021_detect(struct i2c_client *client,
 			  struct i2c_board_info *info)
 {
 	struct i2c_adapter *adapter = client->adapter;
 	const char *type_name;
 	int reg, conv_rate, status, config, man_id, dev_id;

 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) {
 		pr_debug("detect failed, smbus byte data not supported!\n");
 		return -ENODEV;
 	}

 	status = i2c_smbus_read_byte_data(client, ADM1021_REG_STATUS);
 	conv_rate = i2c_smbus_read_byte_data(client,
 					     ADM1021_REG_CONV_RATE_R);
 	config = i2c_smbus_read_byte_data(client, ADM1021_REG_CONFIG_R);

 	/* Check unused bits */
 	if ((status & 0x03) || (config & 0x3F) || (conv_rate & 0xF8)) {
 		pr_debug("detect failed, chip not detected!\n");
 		return -ENODEV;
 	}

 	/* Determine the chip type. */
 	man_id = i2c_smbus_read_byte_data(client, ADM1021_REG_MAN_ID);
 	dev_id = i2c_smbus_read_byte_data(client, ADM1021_REG_DEV_ID);

 	if (man_id < 0 || dev_id < 0)
 		return -ENODEV;

 	if (man_id == 0x4d && dev_id == 0x01) {
 		/*
 		 * dev_id 0x01 matches MAX6680, MAX6695, MAX6696, and possibly
 		 * others. Read register which is unsupported on MAX1617 but
 		 * exists on all those chips and compare with the dev_id
 		 * register. If it matches, it may be a MAX1617A.
 		 */
 		reg = i2c_smbus_read_byte_data(client,
 					       ADM1023_REG_REM_TEMP_PREC);
 		if (reg != dev_id)
 			return -ENODEV;
 		type_name = "max1617a";
 	} else if (man_id == 0x41) {
 		if ((dev_id & 0xF0) == 0x30)
 			type_name = "adm1023";
 		else if ((dev_id & 0xF0) == 0x00)
 			type_name = "adm1021";
 		else
 			return -ENODEV;
 	} else if (man_id == 0x49)
 		type_name = "thmc10";
 	else if (man_id == 0x23)
 		type_name = "gl523sm";
 	else if (man_id == 0x54)
 		type_name = "mc1066";
 	else {
 		int lte, rte, lhi, rhi, llo, rlo;

 		/* extra checks for LM84 and MAX1617 to avoid misdetections */

 		llo = i2c_smbus_read_byte_data(client, ADM1021_REG_THYST_R(0));
 		rlo = i2c_smbus_read_byte_data(client, ADM1021_REG_THYST_R(1));

 		/* fail if any of the additional register reads failed */
 		if (llo < 0 || rlo < 0)
 			return -ENODEV;

 		lte = i2c_smbus_read_byte_data(client, ADM1021_REG_TEMP(0));
 		rte = i2c_smbus_read_byte_data(client, ADM1021_REG_TEMP(1));
 		lhi = i2c_smbus_read_byte_data(client, ADM1021_REG_TOS_R(0));
 		rhi = i2c_smbus_read_byte_data(client, ADM1021_REG_TOS_R(1));

 		/*
 		 * Fail for negative temperatures and negative high limits.
 		 * This check also catches read errors on the tested registers.
 		 */
 		if ((s8)lte < 0 || (s8)rte < 0 || (s8)lhi < 0 || (s8)rhi < 0)
 			return -ENODEV;

 		/* fail if all registers hold the same value */
 		if (lte == rte && lte == lhi && lte == rhi && lte == llo
 		    && lte == rlo)
 			return -ENODEV;

 		/*
 		 * LM84 Mfr ID is in a different place,
 		 * and it has more unused bits. Registers at 0xfe and 0xff
 		 * are undefined and return the most recently read value,
 		 * here the value of the configuration register.
 		 */
 		if (conv_rate == 0x00
 		    && man_id == config && dev_id == config
 		    && (config & 0x7F) == 0x00
 		    && (status & 0xAB) == 0x00) {
 			type_name = "lm84";
 		} else {
 			if ((config & 0x3f) || (status & 0x03))
 				return -ENODEV;
 			/* fail if low limits are larger than high limits */
 			if ((s8)llo > lhi || (s8)rlo > rhi)
 				return -ENODEV;
 			type_name = "max1617";
 		}
 	}

 	pr_debug("Detected chip %s at adapter %d, address 0x%02x.\n",
 		 type_name, i2c_adapter_id(adapter), client->addr);
 	strscpy(info->type, type_name, I2C_NAME_SIZE);

 	return 0;
 }

 static void adm1021_init_client(struct i2c_client *client)
 {
 	/* Enable ADC and disable suspend mode */
 	i2c_smbus_write_byte_data(client, ADM1021_REG_CONFIG_W,
 		i2c_smbus_read_byte_data(client, ADM1021_REG_CONFIG_R) & 0xBF);
 	/* Set Conversion rate to 1/sec (this can be tinkered with) */
 	i2c_smbus_write_byte_data(client, ADM1021_REG_CONV_RATE_W, 0x04);
 }

 static const struct i2c_device_id adm1021_id[];

 static int adm1021_probe(struct i2c_client *client)
 {
 	struct device *dev = &client->dev;
 	struct adm1021_data *data;
 	struct device *hwmon_dev;

 	data = devm_kzalloc(dev, sizeof(struct adm1021_data), GFP_KERNEL);
 	if (!data)
 		return -ENOMEM;

 	data->client = client;
 	data->type = i2c_match_id(adm1021_id, client)->driver_data;
 	mutex_init(&data->update_lock);

 	/* Initialize the ADM1021 chip */
 	if (data->type != lm84 && !read_only)
 		adm1021_init_client(client);

 	data->groups[0] = &adm1021_group;
 	if (data->type != lm84)
 		data->groups[1] = &adm1021_min_group;

 	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
 							   data, data->groups);

 	return PTR_ERR_OR_ZERO(hwmon_dev);
 }

 static const struct i2c_device_id adm1021_id[] = {
 	{ "adm1021", adm1021 },
 	{ "adm1023", adm1023 },
 	{ "max1617", max1617 },
 	{ "max1617a", max1617a },
 	{ "thmc10", thmc10 },
 	{ "lm84", lm84 },
 	{ "gl523sm", gl523sm },
 	{ "mc1066", mc1066 },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, adm1021_id);

 static struct i2c_driver adm1021_driver = {
 	.class		= I2C_CLASS_HWMON,
 	.driver = {
 		.name	= "adm1021",
 	},
 	.probe_new	= adm1021_probe,
 	.id_table	= adm1021_id,
 	.detect		= adm1021_detect,
 	.address_list	= normal_i2c,
 };

 module_i2c_driver(adm1021_driver);

 MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and "
 		"Philip Edelbrock <phil@netroedge.com>");
 MODULE_DESCRIPTION("adm1021 driver");
 MODULE_LICENSE("GPL");

 module_param(read_only, bool, 0);
 MODULE_PARM_DESC(read_only, "Don't set any values, read only mode");
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* adm1021.c - Part of lm_sensors, Linux kernel modules for hardware
	* monitoring
	* Copyright (c) 1998, 1999 Frodo Looijaard <frodol@dds.nl> and
	* Philip Edelbrock <phil@netroedge.com>
	*/

	#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>


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

	enum chips {
	adm1021, adm1023, max1617, max1617a, thmc10, lm84, gl523sm, mc1066 };

	/* adm1021 constants specified below */

	/* The adm1021 registers */
	/* Read-only */
	/* For nr in 0-1 */
	#define ADM1021_REG_TEMP(nr) (nr)
	#define ADM1021_REG_STATUS 0x02
	/* 0x41 = AD, 0x49 = TI, 0x4D = Maxim, 0x23 = Genesys , 0x54 = Onsemi */
	#define ADM1021_REG_MAN_ID 0xFE
	/* ADM1021 = 0x0X, ADM1023 = 0x3X */
	#define ADM1021_REG_DEV_ID 0xFF
	/* These use different addresses for reading/writing */
	#define ADM1021_REG_CONFIG_R 0x03
	#define ADM1021_REG_CONFIG_W 0x09
	#define ADM1021_REG_CONV_RATE_R 0x04
	#define ADM1021_REG_CONV_RATE_W 0x0A
	/* These are for the ADM1023's additional precision on the remote temp sensor */
	#define ADM1023_REG_REM_TEMP_PREC 0x10
	#define ADM1023_REG_REM_OFFSET 0x11
	#define ADM1023_REG_REM_OFFSET_PREC 0x12
	#define ADM1023_REG_REM_TOS_PREC 0x13
	#define ADM1023_REG_REM_THYST_PREC 0x14
	/* limits */
	/* For nr in 0-1 */
	#define ADM1021_REG_TOS_R(nr) (0x05 + 2 * (nr))
	#define ADM1021_REG_TOS_W(nr) (0x0B + 2 * (nr))
	#define ADM1021_REG_THYST_R(nr) (0x06 + 2 * (nr))
	#define ADM1021_REG_THYST_W(nr) (0x0C + 2 * (nr))
	/* write-only */
	#define ADM1021_REG_ONESHOT 0x0F

	/* Initial values */

	/*
	* Note: Even though I left the low and high limits named os and hyst,
	* they don't quite work like a thermostat the way the LM75 does. I.e.,
	* a lower temp than THYST actually triggers an alarm instead of
	* clearing it. Weird, ey? --Phil
	*/

	/* Each client has this additional data */
	struct adm1021_data {
	struct i2c_client *client;
	enum chips type;

	const struct attribute_group *groups[3];

	struct mutex update_lock;
	bool valid; /* true if following fields are valid */
	char low_power; /* !=0 if device in low power mode */
	unsigned long last_updated; /* In jiffies */

	int temp_max[2]; /* Register values */
	int temp_min[2];
	int temp[2];
	u8 alarms;
	/* Special values for ADM1023 only */
	u8 remote_temp_offset;
	u8 remote_temp_offset_prec;
	};

	/* (amalysh) read only mode, otherwise any limit's writing confuse BIOS */
	static bool read_only;

	static struct adm1021_data adm1021_update_device(struct device dev)
	{
	struct adm1021_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 + HZ / 2)
	\|\| !data->valid) {
	int i;

	dev_dbg(dev, "Starting adm1021 update\n");

	for (i = 0; i < 2; i++) {
	data->temp[i] = 1000 *
	(s8) i2c_smbus_read_byte_data(
	client, ADM1021_REG_TEMP(i));
	data->temp_max[i] = 1000 *
	(s8) i2c_smbus_read_byte_data(
	client, ADM1021_REG_TOS_R(i));
	if (data->type != lm84) {
	data->temp_min[i] = 1000 *
	(s8) i2c_smbus_read_byte_data(client,
	ADM1021_REG_THYST_R(i));
	}
	}
	data->alarms = i2c_smbus_read_byte_data(client,
	ADM1021_REG_STATUS) & 0x7c;
	if (data->type == adm1023) {
	/*
	* The ADM1023 provides 3 extra bits of precision for
	* the remote sensor in extra registers.
	*/
	data->temp[1] += 125 * (i2c_smbus_read_byte_data(
	client, ADM1023_REG_REM_TEMP_PREC) >> 5);
	data->temp_max[1] += 125 * (i2c_smbus_read_byte_data(
	client, ADM1023_REG_REM_TOS_PREC) >> 5);
	data->temp_min[1] += 125 * (i2c_smbus_read_byte_data(
	client, ADM1023_REG_REM_THYST_PREC) >> 5);
	data->remote_temp_offset =
	i2c_smbus_read_byte_data(client,
	ADM1023_REG_REM_OFFSET);
	data->remote_temp_offset_prec =
	i2c_smbus_read_byte_data(client,
	ADM1023_REG_REM_OFFSET_PREC);
	}
	data->last_updated = jiffies;
	data->valid = true;
	}

	mutex_unlock(&data->update_lock);

	return data;
	}

	static ssize_t temp_show(struct device dev, struct device_attribute devattr,
	char *buf)
	{
	int index = to_sensor_dev_attr(devattr)->index;
	struct adm1021_data *data = adm1021_update_device(dev);

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

	static ssize_t temp_max_show(struct device *dev,
	struct device_attribute devattr, char buf)
	{
	int index = to_sensor_dev_attr(devattr)->index;
	struct adm1021_data *data = adm1021_update_device(dev);

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

	static ssize_t temp_min_show(struct device *dev,
	struct device_attribute devattr, char buf)
	{
	int index = to_sensor_dev_attr(devattr)->index;
	struct adm1021_data *data = adm1021_update_device(dev);

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

	static ssize_t alarm_show(struct device dev, struct device_attribute attr,
	char *buf)
	{
	int index = to_sensor_dev_attr(attr)->index;
	struct adm1021_data *data = adm1021_update_device(dev);
	return sprintf(buf, "%u\n", (data->alarms >> index) & 1);
	}

	static ssize_t alarms_show(struct device *dev,
	struct device_attribute *attr,
	char *buf)
	{
	struct adm1021_data *data = adm1021_update_device(dev);
	return sprintf(buf, "%u\n", data->alarms);
	}

	static ssize_t temp_max_store(struct device *dev,
	struct device_attribute *devattr,
	const char *buf, size_t count)
	{
	int index = to_sensor_dev_attr(devattr)->index;
	struct adm1021_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;
	long temp;
	int reg_val, err;

	err = kstrtol(buf, 10, &temp);
	if (err)
	return err;
	temp /= 1000;

	mutex_lock(&data->update_lock);
	reg_val = clamp_val(temp, -128, 127);
	data->temp_max[index] = reg_val * 1000;
	if (!read_only)
	i2c_smbus_write_byte_data(client, ADM1021_REG_TOS_W(index),
	reg_val);
	mutex_unlock(&data->update_lock);

	return count;
	}

	static ssize_t temp_min_store(struct device *dev,
	struct device_attribute *devattr,
	const char *buf, size_t count)
	{
	int index = to_sensor_dev_attr(devattr)->index;
	struct adm1021_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;
	long temp;
	int reg_val, err;

	err = kstrtol(buf, 10, &temp);
	if (err)
	return err;
	temp /= 1000;

	mutex_lock(&data->update_lock);
	reg_val = clamp_val(temp, -128, 127);
	data->temp_min[index] = reg_val * 1000;
	if (!read_only)
	i2c_smbus_write_byte_data(client, ADM1021_REG_THYST_W(index),
	reg_val);
	mutex_unlock(&data->update_lock);

	return count;
	}

	static ssize_t low_power_show(struct device *dev,
	struct device_attribute devattr, char buf)
	{
	struct adm1021_data *data = adm1021_update_device(dev);
	return sprintf(buf, "%d\n", data->low_power);
	}

	static ssize_t low_power_store(struct device *dev,
	struct device_attribute *devattr,
	const char *buf, size_t count)
	{
	struct adm1021_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;
	char low_power;
	unsigned long val;
	int err;

	err = kstrtoul(buf, 10, &val);
	if (err)
	return err;
	low_power = val != 0;

	mutex_lock(&data->update_lock);
	if (low_power != data->low_power) {
	int config = i2c_smbus_read_byte_data(
	client, ADM1021_REG_CONFIG_R);
	data->low_power = low_power;
	i2c_smbus_write_byte_data(client, ADM1021_REG_CONFIG_W,
	(config & 0xBF) \| (low_power << 6));
	}
	mutex_unlock(&data->update_lock);

	return count;
	}


	static SENSOR_DEVICE_ATTR_RO(temp1_input, temp, 0);
	static SENSOR_DEVICE_ATTR_RW(temp1_max, temp_max, 0);
	static SENSOR_DEVICE_ATTR_RW(temp1_min, temp_min, 0);
	static SENSOR_DEVICE_ATTR_RO(temp2_input, temp, 1);
	static SENSOR_DEVICE_ATTR_RW(temp2_max, temp_max, 1);
	static SENSOR_DEVICE_ATTR_RW(temp2_min, temp_min, 1);
	static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, alarm, 6);
	static SENSOR_DEVICE_ATTR_RO(temp1_min_alarm, alarm, 5);
	static SENSOR_DEVICE_ATTR_RO(temp2_max_alarm, alarm, 4);
	static SENSOR_DEVICE_ATTR_RO(temp2_min_alarm, alarm, 3);
	static SENSOR_DEVICE_ATTR_RO(temp2_fault, alarm, 2);

	static DEVICE_ATTR_RO(alarms);
	static DEVICE_ATTR_RW(low_power);

	static struct attribute *adm1021_attributes[] = {
	&sensor_dev_attr_temp1_max.dev_attr.attr,
	&sensor_dev_attr_temp1_input.dev_attr.attr,
	&sensor_dev_attr_temp2_max.dev_attr.attr,
	&sensor_dev_attr_temp2_input.dev_attr.attr,
	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
	&sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
	&sensor_dev_attr_temp2_fault.dev_attr.attr,
	&dev_attr_alarms.attr,
	&dev_attr_low_power.attr,
	NULL
	};

	static const struct attribute_group adm1021_group = {
	.attrs = adm1021_attributes,
	};

	static struct attribute *adm1021_min_attributes[] = {
	&sensor_dev_attr_temp1_min.dev_attr.attr,
	&sensor_dev_attr_temp2_min.dev_attr.attr,
	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
	&sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
	NULL
	};

	static const struct attribute_group adm1021_min_group = {
	.attrs = adm1021_min_attributes,
	};

	/* Return 0 if detection is successful, -ENODEV otherwise */
	static int adm1021_detect(struct i2c_client *client,
	struct i2c_board_info *info)
	{
	struct i2c_adapter *adapter = client->adapter;
	const char *type_name;
	int reg, conv_rate, status, config, man_id, dev_id;

	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) {
	pr_debug("detect failed, smbus byte data not supported!\n");
	return -ENODEV;
	}

	status = i2c_smbus_read_byte_data(client, ADM1021_REG_STATUS);
	conv_rate = i2c_smbus_read_byte_data(client,
	ADM1021_REG_CONV_RATE_R);
	config = i2c_smbus_read_byte_data(client, ADM1021_REG_CONFIG_R);

	/* Check unused bits */
	if ((status & 0x03) \|\| (config & 0x3F) \|\| (conv_rate & 0xF8)) {
	pr_debug("detect failed, chip not detected!\n");
	return -ENODEV;
	}

	/* Determine the chip type. */
	man_id = i2c_smbus_read_byte_data(client, ADM1021_REG_MAN_ID);
	dev_id = i2c_smbus_read_byte_data(client, ADM1021_REG_DEV_ID);

	if (man_id < 0 \|\| dev_id < 0)
	return -ENODEV;

	if (man_id == 0x4d && dev_id == 0x01) {
	/*
	* dev_id 0x01 matches MAX6680, MAX6695, MAX6696, and possibly
	* others. Read register which is unsupported on MAX1617 but
	* exists on all those chips and compare with the dev_id
	* register. If it matches, it may be a MAX1617A.
	*/
	reg = i2c_smbus_read_byte_data(client,
	ADM1023_REG_REM_TEMP_PREC);
	if (reg != dev_id)
	return -ENODEV;
	type_name = "max1617a";
	} else if (man_id == 0x41) {
	if ((dev_id & 0xF0) == 0x30)
	type_name = "adm1023";
	else if ((dev_id & 0xF0) == 0x00)
	type_name = "adm1021";
	else
	return -ENODEV;
	} else if (man_id == 0x49)
	type_name = "thmc10";
	else if (man_id == 0x23)
	type_name = "gl523sm";
	else if (man_id == 0x54)
	type_name = "mc1066";
	else {
	int lte, rte, lhi, rhi, llo, rlo;

	/* extra checks for LM84 and MAX1617 to avoid misdetections */

	llo = i2c_smbus_read_byte_data(client, ADM1021_REG_THYST_R(0));
	rlo = i2c_smbus_read_byte_data(client, ADM1021_REG_THYST_R(1));

	/* fail if any of the additional register reads failed */
	if (llo < 0 \|\| rlo < 0)
	return -ENODEV;

	lte = i2c_smbus_read_byte_data(client, ADM1021_REG_TEMP(0));
	rte = i2c_smbus_read_byte_data(client, ADM1021_REG_TEMP(1));
	lhi = i2c_smbus_read_byte_data(client, ADM1021_REG_TOS_R(0));
	rhi = i2c_smbus_read_byte_data(client, ADM1021_REG_TOS_R(1));

	/*
	* Fail for negative temperatures and negative high limits.
	* This check also catches read errors on the tested registers.
	*/
	if ((s8)lte < 0 \|\| (s8)rte < 0 \|\| (s8)lhi < 0 \|\| (s8)rhi < 0)
	return -ENODEV;

	/* fail if all registers hold the same value */
	if (lte == rte && lte == lhi && lte == rhi && lte == llo
	&& lte == rlo)
	return -ENODEV;

	/*
	* LM84 Mfr ID is in a different place,
	* and it has more unused bits. Registers at 0xfe and 0xff
	* are undefined and return the most recently read value,
	* here the value of the configuration register.
	*/
	if (conv_rate == 0x00
	&& man_id == config && dev_id == config
	&& (config & 0x7F) == 0x00
	&& (status & 0xAB) == 0x00) {
	type_name = "lm84";
	} else {
	if ((config & 0x3f) \|\| (status & 0x03))
	return -ENODEV;
	/* fail if low limits are larger than high limits */
	if ((s8)llo > lhi \|\| (s8)rlo > rhi)
	return -ENODEV;
	type_name = "max1617";
	}
	}

	pr_debug("Detected chip %s at adapter %d, address 0x%02x.\n",
	type_name, i2c_adapter_id(adapter), client->addr);
	strscpy(info->type, type_name, I2C_NAME_SIZE);

	return 0;
	}

	static void adm1021_init_client(struct i2c_client *client)
	{
	/* Enable ADC and disable suspend mode */
	i2c_smbus_write_byte_data(client, ADM1021_REG_CONFIG_W,
	i2c_smbus_read_byte_data(client, ADM1021_REG_CONFIG_R) & 0xBF);
	/* Set Conversion rate to 1/sec (this can be tinkered with) */
	i2c_smbus_write_byte_data(client, ADM1021_REG_CONV_RATE_W, 0x04);
	}

	static const struct i2c_device_id adm1021_id[];

	static int adm1021_probe(struct i2c_client *client)
	{
	struct device *dev = &client->dev;
	struct adm1021_data *data;
	struct device *hwmon_dev;

	data = devm_kzalloc(dev, sizeof(struct adm1021_data), GFP_KERNEL);
	if (!data)
	return -ENOMEM;

	data->client = client;
	data->type = i2c_match_id(adm1021_id, client)->driver_data;
	mutex_init(&data->update_lock);

	/* Initialize the ADM1021 chip */
	if (data->type != lm84 && !read_only)
	adm1021_init_client(client);

	data->groups[0] = &adm1021_group;
	if (data->type != lm84)
	data->groups[1] = &adm1021_min_group;

	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
	data, data->groups);

	return PTR_ERR_OR_ZERO(hwmon_dev);
	}

	static const struct i2c_device_id adm1021_id[] = {
	{ "adm1021", adm1021 },
	{ "adm1023", adm1023 },
	{ "max1617", max1617 },
	{ "max1617a", max1617a },
	{ "thmc10", thmc10 },
	{ "lm84", lm84 },
	{ "gl523sm", gl523sm },
	{ "mc1066", mc1066 },
	{ }
	};
	MODULE_DEVICE_TABLE(i2c, adm1021_id);

	static struct i2c_driver adm1021_driver = {
	.class = I2C_CLASS_HWMON,
	.driver = {
	.name = "adm1021",
	},
	.probe_new = adm1021_probe,
	.id_table = adm1021_id,
	.detect = adm1021_detect,
	.address_list = normal_i2c,
	};

	module_i2c_driver(adm1021_driver);

	MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and "
	"Philip Edelbrock <phil@netroedge.com>");
	MODULE_DESCRIPTION("adm1021 driver");
	MODULE_LICENSE("GPL");

	module_param(read_only, bool, 0);
	MODULE_PARM_DESC(read_only, "Don't set any values, read only mode");