drivers/hwmon/emc1403.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * emc1403.c - SMSC Thermal Driver
  *
  * Copyright (C) 2008 Intel Corp
  *
  *  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  *
  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  */

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

 #define THERMAL_PID_REG		0xfd
 #define THERMAL_SMSC_ID_REG	0xfe
 #define THERMAL_REVISION_REG	0xff

 enum emc1403_chip { emc1402, emc1403, emc1404 };

 struct thermal_data {
 	struct regmap *regmap;
 	struct mutex mutex;
 	const struct attribute_group *groups[4];
 };

 static ssize_t temp_show(struct device *dev, struct device_attribute *attr,
 			 char *buf)
 {
 	struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
 	struct thermal_data *data = dev_get_drvdata(dev);
 	unsigned int val;
 	int retval;

 	retval = regmap_read(data->regmap, sda->index, &val);
 	if (retval < 0)
 		return retval;
 	return sprintf(buf, "%d000\n", val);
 }

 static ssize_t bit_show(struct device *dev, struct device_attribute *attr,
 			char *buf)
 {
 	struct sensor_device_attribute_2 *sda = to_sensor_dev_attr_2(attr);
 	struct thermal_data *data = dev_get_drvdata(dev);
 	unsigned int val;
 	int retval;

 	retval = regmap_read(data->regmap, sda->nr, &val);
 	if (retval < 0)
 		return retval;
 	return sprintf(buf, "%d\n", !!(val & sda->index));
 }

 static ssize_t temp_store(struct device *dev, struct device_attribute *attr,
 			  const char *buf, size_t count)
 {
 	struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
 	struct thermal_data *data = dev_get_drvdata(dev);
 	unsigned long val;
 	int retval;

 	if (kstrtoul(buf, 10, &val))
 		return -EINVAL;
 	retval = regmap_write(data->regmap, sda->index,
 			      DIV_ROUND_CLOSEST(val, 1000));
 	if (retval < 0)
 		return retval;
 	return count;
 }

 static ssize_t bit_store(struct device *dev, struct device_attribute *attr,
 			 const char *buf, size_t count)
 {
 	struct sensor_device_attribute_2 *sda = to_sensor_dev_attr_2(attr);
 	struct thermal_data *data = dev_get_drvdata(dev);
 	unsigned long val;
 	int retval;

 	if (kstrtoul(buf, 10, &val))
 		return -EINVAL;

 	retval = regmap_update_bits(data->regmap, sda->nr, sda->index,
 				    val ? sda->index : 0);
 	if (retval < 0)
 		return retval;
 	return count;
 }

 static ssize_t show_hyst_common(struct device *dev,
 				struct device_attribute *attr, char *buf,
 				bool is_min)
 {
 	struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
 	struct thermal_data *data = dev_get_drvdata(dev);
 	struct regmap *regmap = data->regmap;
 	unsigned int limit;
 	unsigned int hyst;
 	int retval;

 	retval = regmap_read(regmap, sda->index, &limit);
 	if (retval < 0)
 		return retval;

 	retval = regmap_read(regmap, 0x21, &hyst);
 	if (retval < 0)
 		return retval;

 	return sprintf(buf, "%d000\n", is_min ? limit + hyst : limit - hyst);
 }

 static ssize_t hyst_show(struct device *dev, struct device_attribute *attr,
 			 char *buf)
 {
 	return show_hyst_common(dev, attr, buf, false);
 }

 static ssize_t min_hyst_show(struct device *dev,
 			     struct device_attribute *attr, char *buf)
 {
 	return show_hyst_common(dev, attr, buf, true);
 }

 static ssize_t hyst_store(struct device *dev, struct device_attribute *attr,
 			  const char *buf, size_t count)
 {
 	struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
 	struct thermal_data *data = dev_get_drvdata(dev);
 	struct regmap *regmap = data->regmap;
 	unsigned int limit;
 	int retval;
 	int hyst;
 	unsigned long val;

 	if (kstrtoul(buf, 10, &val))
 		return -EINVAL;

 	mutex_lock(&data->mutex);
 	retval = regmap_read(regmap, sda->index, &limit);
 	if (retval < 0)
 		goto fail;

 	hyst = limit * 1000 - val;
 	hyst = clamp_val(DIV_ROUND_CLOSEST(hyst, 1000), 0, 255);
 	retval = regmap_write(regmap, 0x21, hyst);
 	if (retval == 0)
 		retval = count;
 fail:
 	mutex_unlock(&data->mutex);
 	return retval;
 }

 /*
  *	Sensors. We pass the actual i2c register to the methods.
  */

 static SENSOR_DEVICE_ATTR_RW(temp1_min, temp, 0x06);
 static SENSOR_DEVICE_ATTR_RW(temp1_max, temp, 0x05);
 static SENSOR_DEVICE_ATTR_RW(temp1_crit, temp, 0x20);
 static SENSOR_DEVICE_ATTR_RO(temp1_input, temp, 0x00);
 static SENSOR_DEVICE_ATTR_2_RO(temp1_min_alarm, bit, 0x36, 0x01);
 static SENSOR_DEVICE_ATTR_2_RO(temp1_max_alarm, bit, 0x35, 0x01);
 static SENSOR_DEVICE_ATTR_2_RO(temp1_crit_alarm, bit, 0x37, 0x01);
 static SENSOR_DEVICE_ATTR_RO(temp1_min_hyst, min_hyst, 0x06);
 static SENSOR_DEVICE_ATTR_RO(temp1_max_hyst, hyst, 0x05);
 static SENSOR_DEVICE_ATTR_RW(temp1_crit_hyst, hyst, 0x20);

 static SENSOR_DEVICE_ATTR_RW(temp2_min, temp, 0x08);
 static SENSOR_DEVICE_ATTR_RW(temp2_max, temp, 0x07);
 static SENSOR_DEVICE_ATTR_RW(temp2_crit, temp, 0x19);
 static SENSOR_DEVICE_ATTR_RO(temp2_input, temp, 0x01);
 static SENSOR_DEVICE_ATTR_2_RO(temp2_fault, bit, 0x1b, 0x02);
 static SENSOR_DEVICE_ATTR_2_RO(temp2_min_alarm, bit, 0x36, 0x02);
 static SENSOR_DEVICE_ATTR_2_RO(temp2_max_alarm, bit, 0x35, 0x02);
 static SENSOR_DEVICE_ATTR_2_RO(temp2_crit_alarm, bit, 0x37, 0x02);
 static SENSOR_DEVICE_ATTR_RO(temp2_min_hyst, min_hyst, 0x08);
 static SENSOR_DEVICE_ATTR_RO(temp2_max_hyst, hyst, 0x07);
 static SENSOR_DEVICE_ATTR_RO(temp2_crit_hyst, hyst, 0x19);

 static SENSOR_DEVICE_ATTR_RW(temp3_min, temp, 0x16);
 static SENSOR_DEVICE_ATTR_RW(temp3_max, temp, 0x15);
 static SENSOR_DEVICE_ATTR_RW(temp3_crit, temp, 0x1A);
 static SENSOR_DEVICE_ATTR_RO(temp3_input, temp, 0x23);
 static SENSOR_DEVICE_ATTR_2_RO(temp3_fault, bit, 0x1b, 0x04);
 static SENSOR_DEVICE_ATTR_2_RO(temp3_min_alarm, bit, 0x36, 0x04);
 static SENSOR_DEVICE_ATTR_2_RO(temp3_max_alarm, bit, 0x35, 0x04);
 static SENSOR_DEVICE_ATTR_2_RO(temp3_crit_alarm, bit, 0x37, 0x04);
 static SENSOR_DEVICE_ATTR_RO(temp3_min_hyst, min_hyst, 0x16);
 static SENSOR_DEVICE_ATTR_RO(temp3_max_hyst, hyst, 0x15);
 static SENSOR_DEVICE_ATTR_RO(temp3_crit_hyst, hyst, 0x1A);

 static SENSOR_DEVICE_ATTR_RW(temp4_min, temp, 0x2D);
 static SENSOR_DEVICE_ATTR_RW(temp4_max, temp, 0x2C);
 static SENSOR_DEVICE_ATTR_RW(temp4_crit, temp, 0x30);
 static SENSOR_DEVICE_ATTR_RO(temp4_input, temp, 0x2A);
 static SENSOR_DEVICE_ATTR_2_RO(temp4_fault, bit, 0x1b, 0x08);
 static SENSOR_DEVICE_ATTR_2_RO(temp4_min_alarm, bit, 0x36, 0x08);
 static SENSOR_DEVICE_ATTR_2_RO(temp4_max_alarm, bit, 0x35, 0x08);
 static SENSOR_DEVICE_ATTR_2_RO(temp4_crit_alarm, bit, 0x37, 0x08);
 static SENSOR_DEVICE_ATTR_RO(temp4_min_hyst, min_hyst, 0x2D);
 static SENSOR_DEVICE_ATTR_RO(temp4_max_hyst, hyst, 0x2C);
 static SENSOR_DEVICE_ATTR_RO(temp4_crit_hyst, hyst, 0x30);

 static SENSOR_DEVICE_ATTR_2_RW(power_state, bit, 0x03, 0x40);

 static struct attribute *emc1402_attrs[] = {
 	&sensor_dev_attr_temp1_min.dev_attr.attr,
 	&sensor_dev_attr_temp1_max.dev_attr.attr,
 	&sensor_dev_attr_temp1_crit.dev_attr.attr,
 	&sensor_dev_attr_temp1_input.dev_attr.attr,
 	&sensor_dev_attr_temp1_min_hyst.dev_attr.attr,
 	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
 	&sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,

 	&sensor_dev_attr_temp2_min.dev_attr.attr,
 	&sensor_dev_attr_temp2_max.dev_attr.attr,
 	&sensor_dev_attr_temp2_crit.dev_attr.attr,
 	&sensor_dev_attr_temp2_input.dev_attr.attr,
 	&sensor_dev_attr_temp2_min_hyst.dev_attr.attr,
 	&sensor_dev_attr_temp2_max_hyst.dev_attr.attr,
 	&sensor_dev_attr_temp2_crit_hyst.dev_attr.attr,

 	&sensor_dev_attr_power_state.dev_attr.attr,
 	NULL
 };

 static const struct attribute_group emc1402_group = {
 		.attrs = emc1402_attrs,
 };

 static struct attribute *emc1403_attrs[] = {
 	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
 	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
 	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,

 	&sensor_dev_attr_temp2_fault.dev_attr.attr,
 	&sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
 	&sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
 	&sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,

 	&sensor_dev_attr_temp3_min.dev_attr.attr,
 	&sensor_dev_attr_temp3_max.dev_attr.attr,
 	&sensor_dev_attr_temp3_crit.dev_attr.attr,
 	&sensor_dev_attr_temp3_input.dev_attr.attr,
 	&sensor_dev_attr_temp3_fault.dev_attr.attr,
 	&sensor_dev_attr_temp3_min_alarm.dev_attr.attr,
 	&sensor_dev_attr_temp3_max_alarm.dev_attr.attr,
 	&sensor_dev_attr_temp3_crit_alarm.dev_attr.attr,
 	&sensor_dev_attr_temp3_min_hyst.dev_attr.attr,
 	&sensor_dev_attr_temp3_max_hyst.dev_attr.attr,
 	&sensor_dev_attr_temp3_crit_hyst.dev_attr.attr,
 	NULL
 };

 static const struct attribute_group emc1403_group = {
 	.attrs = emc1403_attrs,
 };

 static struct attribute *emc1404_attrs[] = {
 	&sensor_dev_attr_temp4_min.dev_attr.attr,
 	&sensor_dev_attr_temp4_max.dev_attr.attr,
 	&sensor_dev_attr_temp4_crit.dev_attr.attr,
 	&sensor_dev_attr_temp4_input.dev_attr.attr,
 	&sensor_dev_attr_temp4_fault.dev_attr.attr,
 	&sensor_dev_attr_temp4_min_alarm.dev_attr.attr,
 	&sensor_dev_attr_temp4_max_alarm.dev_attr.attr,
 	&sensor_dev_attr_temp4_crit_alarm.dev_attr.attr,
 	&sensor_dev_attr_temp4_min_hyst.dev_attr.attr,
 	&sensor_dev_attr_temp4_max_hyst.dev_attr.attr,
 	&sensor_dev_attr_temp4_crit_hyst.dev_attr.attr,
 	NULL
 };

 static const struct attribute_group emc1404_group = {
 	.attrs = emc1404_attrs,
 };

 /*
  * EMC14x2 uses a different register and different bits to report alarm and
  * fault status. For simplicity, provide a separate attribute group for this
  * chip series.
  * Since we can not re-use the same attribute names, create a separate attribute
  * array.
  */
 static struct sensor_device_attribute_2 emc1402_alarms[] = {
 	SENSOR_ATTR_2_RO(temp1_min_alarm, bit, 0x02, 0x20),
 	SENSOR_ATTR_2_RO(temp1_max_alarm, bit, 0x02, 0x40),
 	SENSOR_ATTR_2_RO(temp1_crit_alarm, bit, 0x02, 0x01),

 	SENSOR_ATTR_2_RO(temp2_fault, bit, 0x02, 0x04),
 	SENSOR_ATTR_2_RO(temp2_min_alarm, bit, 0x02, 0x08),
 	SENSOR_ATTR_2_RO(temp2_max_alarm, bit, 0x02, 0x10),
 	SENSOR_ATTR_2_RO(temp2_crit_alarm, bit, 0x02, 0x02),
 };

 static struct attribute *emc1402_alarm_attrs[] = {
 	&emc1402_alarms[0].dev_attr.attr,
 	&emc1402_alarms[1].dev_attr.attr,
 	&emc1402_alarms[2].dev_attr.attr,
 	&emc1402_alarms[3].dev_attr.attr,
 	&emc1402_alarms[4].dev_attr.attr,
 	&emc1402_alarms[5].dev_attr.attr,
 	&emc1402_alarms[6].dev_attr.attr,
 	NULL,
 };

 static const struct attribute_group emc1402_alarm_group = {
 	.attrs = emc1402_alarm_attrs,
 };

 static int emc1403_detect(struct i2c_client *client,
 			struct i2c_board_info *info)
 {
 	int id;
 	/* Check if thermal chip is SMSC and EMC1403 or EMC1423 */

 	id = i2c_smbus_read_byte_data(client, THERMAL_SMSC_ID_REG);
 	if (id != 0x5d)
 		return -ENODEV;

 	id = i2c_smbus_read_byte_data(client, THERMAL_PID_REG);
 	switch (id) {
 	case 0x20:
 		strscpy(info->type, "emc1402", I2C_NAME_SIZE);
 		break;
 	case 0x21:
 		strscpy(info->type, "emc1403", I2C_NAME_SIZE);
 		break;
 	case 0x22:
 		strscpy(info->type, "emc1422", I2C_NAME_SIZE);
 		break;
 	case 0x23:
 		strscpy(info->type, "emc1423", I2C_NAME_SIZE);
 		break;
 	case 0x25:
 		strscpy(info->type, "emc1404", I2C_NAME_SIZE);
 		break;
 	case 0x27:
 		strscpy(info->type, "emc1424", I2C_NAME_SIZE);
 		break;
 	default:
 		return -ENODEV;
 	}

 	id = i2c_smbus_read_byte_data(client, THERMAL_REVISION_REG);
 	if (id < 0x01 || id > 0x04)
 		return -ENODEV;

 	return 0;
 }

 static bool emc1403_regmap_is_volatile(struct device *dev, unsigned int reg)
 {
 	switch (reg) {
 	case 0x00:	/* internal diode high byte */
 	case 0x01:	/* external diode 1 high byte */
 	case 0x02:	/* status */
 	case 0x10:	/* external diode 1 low byte */
 	case 0x1b:	/* external diode fault */
 	case 0x23:	/* external diode 2 high byte */
 	case 0x24:	/* external diode 2 low byte */
 	case 0x29:	/* internal diode low byte */
 	case 0x2a:	/* externl diode 3 high byte */
 	case 0x2b:	/* external diode 3 low byte */
 	case 0x35:	/* high limit status */
 	case 0x36:	/* low limit status */
 	case 0x37:	/* therm limit status */
 		return true;
 	default:
 		return false;
 	}
 }

 static const struct regmap_config emc1403_regmap_config = {
 	.reg_bits = 8,
 	.val_bits = 8,
 	.cache_type = REGCACHE_RBTREE,
 	.volatile_reg = emc1403_regmap_is_volatile,
 };

 static const struct i2c_device_id emc1403_idtable[];

 static int emc1403_probe(struct i2c_client *client)
 {
 	struct thermal_data *data;
 	struct device *hwmon_dev;
 	const struct i2c_device_id *id = i2c_match_id(emc1403_idtable, client);

 	data = devm_kzalloc(&client->dev, sizeof(struct thermal_data),
 			    GFP_KERNEL);
 	if (data == NULL)
 		return -ENOMEM;

 	data->regmap = devm_regmap_init_i2c(client, &emc1403_regmap_config);
 	if (IS_ERR(data->regmap))
 		return PTR_ERR(data->regmap);

 	mutex_init(&data->mutex);

 	switch (id->driver_data) {
 	case emc1404:
 		data->groups[2] = &emc1404_group;
 		fallthrough;
 	case emc1403:
 		data->groups[1] = &emc1403_group;
 		fallthrough;
 	case emc1402:
 		data->groups[0] = &emc1402_group;
 	}

 	if (id->driver_data == emc1402)
 		data->groups[1] = &emc1402_alarm_group;

 	hwmon_dev = devm_hwmon_device_register_with_groups(&client->dev,
 							   client->name, data,
 							   data->groups);
 	if (IS_ERR(hwmon_dev))
 		return PTR_ERR(hwmon_dev);

 	dev_info(&client->dev, "%s Thermal chip found\n", id->name);
 	return 0;
 }

 static const unsigned short emc1403_address_list[] = {
 	0x18, 0x1c, 0x29, 0x4c, 0x4d, 0x5c, I2C_CLIENT_END
 };

 /* Last digit of chip name indicates number of channels */
 static const struct i2c_device_id emc1403_idtable[] = {
 	{ "emc1402", emc1402 },
 	{ "emc1403", emc1403 },
 	{ "emc1404", emc1404 },
 	{ "emc1412", emc1402 },
 	{ "emc1413", emc1403 },
 	{ "emc1414", emc1404 },
 	{ "emc1422", emc1402 },
 	{ "emc1423", emc1403 },
 	{ "emc1424", emc1404 },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, emc1403_idtable);

 static struct i2c_driver sensor_emc1403 = {
 	.class = I2C_CLASS_HWMON,
 	.driver = {
 		.name = "emc1403",
 	},
 	.detect = emc1403_detect,
 	.probe = emc1403_probe,
 	.id_table = emc1403_idtable,
 	.address_list = emc1403_address_list,
 };

 module_i2c_driver(sensor_emc1403);

 MODULE_AUTHOR("Kalhan Trisal <kalhan.trisal@intel.com");
 MODULE_DESCRIPTION("emc1403 Thermal Driver");
 MODULE_LICENSE("GPL v2");
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* emc1403.c - SMSC Thermal Driver
	*
	* Copyright (C) 2008 Intel Corp
	*
	* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	*
	* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	*/

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

	#define THERMAL_PID_REG 0xfd
	#define THERMAL_SMSC_ID_REG 0xfe
	#define THERMAL_REVISION_REG 0xff

	enum emc1403_chip { emc1402, emc1403, emc1404 };

	struct thermal_data {
	struct regmap *regmap;
	struct mutex mutex;
	const struct attribute_group *groups[4];
	};

	static ssize_t temp_show(struct device dev, struct device_attribute attr,
	char *buf)
	{
	struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
	struct thermal_data *data = dev_get_drvdata(dev);
	unsigned int val;
	int retval;

	retval = regmap_read(data->regmap, sda->index, &val);
	if (retval < 0)
	return retval;
	return sprintf(buf, "%d000\n", val);
	}

	static ssize_t bit_show(struct device dev, struct device_attribute attr,
	char *buf)
	{
	struct sensor_device_attribute_2 *sda = to_sensor_dev_attr_2(attr);
	struct thermal_data *data = dev_get_drvdata(dev);
	unsigned int val;
	int retval;

	retval = regmap_read(data->regmap, sda->nr, &val);
	if (retval < 0)
	return retval;
	return sprintf(buf, "%d\n", !!(val & sda->index));
	}

	static ssize_t temp_store(struct device dev, struct device_attribute attr,
	const char *buf, size_t count)
	{
	struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
	struct thermal_data *data = dev_get_drvdata(dev);
	unsigned long val;
	int retval;

	if (kstrtoul(buf, 10, &val))
	return -EINVAL;
	retval = regmap_write(data->regmap, sda->index,
	DIV_ROUND_CLOSEST(val, 1000));
	if (retval < 0)
	return retval;
	return count;
	}

	static ssize_t bit_store(struct device dev, struct device_attribute attr,
	const char *buf, size_t count)
	{
	struct sensor_device_attribute_2 *sda = to_sensor_dev_attr_2(attr);
	struct thermal_data *data = dev_get_drvdata(dev);
	unsigned long val;
	int retval;

	if (kstrtoul(buf, 10, &val))
	return -EINVAL;

	retval = regmap_update_bits(data->regmap, sda->nr, sda->index,
	val ? sda->index : 0);
	if (retval < 0)
	return retval;
	return count;
	}

	static ssize_t show_hyst_common(struct device *dev,
	struct device_attribute attr, char buf,
	bool is_min)
	{
	struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
	struct thermal_data *data = dev_get_drvdata(dev);
	struct regmap *regmap = data->regmap;
	unsigned int limit;
	unsigned int hyst;
	int retval;

	retval = regmap_read(regmap, sda->index, &limit);
	if (retval < 0)
	return retval;

	retval = regmap_read(regmap, 0x21, &hyst);
	if (retval < 0)
	return retval;

	return sprintf(buf, "%d000\n", is_min ? limit + hyst : limit - hyst);
	}

	static ssize_t hyst_show(struct device dev, struct device_attribute attr,
	char *buf)
	{
	return show_hyst_common(dev, attr, buf, false);
	}

	static ssize_t min_hyst_show(struct device *dev,
	struct device_attribute attr, char buf)
	{
	return show_hyst_common(dev, attr, buf, true);
	}

	static ssize_t hyst_store(struct device dev, struct device_attribute attr,
	const char *buf, size_t count)
	{
	struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
	struct thermal_data *data = dev_get_drvdata(dev);
	struct regmap *regmap = data->regmap;
	unsigned int limit;
	int retval;
	int hyst;
	unsigned long val;

	if (kstrtoul(buf, 10, &val))
	return -EINVAL;

	mutex_lock(&data->mutex);
	retval = regmap_read(regmap, sda->index, &limit);
	if (retval < 0)
	goto fail;

	hyst = limit * 1000 - val;
	hyst = clamp_val(DIV_ROUND_CLOSEST(hyst, 1000), 0, 255);
	retval = regmap_write(regmap, 0x21, hyst);
	if (retval == 0)
	retval = count;
	fail:
	mutex_unlock(&data->mutex);
	return retval;
	}

	/*
	* Sensors. We pass the actual i2c register to the methods.
	*/

	static SENSOR_DEVICE_ATTR_RW(temp1_min, temp, 0x06);
	static SENSOR_DEVICE_ATTR_RW(temp1_max, temp, 0x05);
	static SENSOR_DEVICE_ATTR_RW(temp1_crit, temp, 0x20);
	static SENSOR_DEVICE_ATTR_RO(temp1_input, temp, 0x00);
	static SENSOR_DEVICE_ATTR_2_RO(temp1_min_alarm, bit, 0x36, 0x01);
	static SENSOR_DEVICE_ATTR_2_RO(temp1_max_alarm, bit, 0x35, 0x01);
	static SENSOR_DEVICE_ATTR_2_RO(temp1_crit_alarm, bit, 0x37, 0x01);
	static SENSOR_DEVICE_ATTR_RO(temp1_min_hyst, min_hyst, 0x06);
	static SENSOR_DEVICE_ATTR_RO(temp1_max_hyst, hyst, 0x05);
	static SENSOR_DEVICE_ATTR_RW(temp1_crit_hyst, hyst, 0x20);

	static SENSOR_DEVICE_ATTR_RW(temp2_min, temp, 0x08);
	static SENSOR_DEVICE_ATTR_RW(temp2_max, temp, 0x07);
	static SENSOR_DEVICE_ATTR_RW(temp2_crit, temp, 0x19);
	static SENSOR_DEVICE_ATTR_RO(temp2_input, temp, 0x01);
	static SENSOR_DEVICE_ATTR_2_RO(temp2_fault, bit, 0x1b, 0x02);
	static SENSOR_DEVICE_ATTR_2_RO(temp2_min_alarm, bit, 0x36, 0x02);
	static SENSOR_DEVICE_ATTR_2_RO(temp2_max_alarm, bit, 0x35, 0x02);
	static SENSOR_DEVICE_ATTR_2_RO(temp2_crit_alarm, bit, 0x37, 0x02);
	static SENSOR_DEVICE_ATTR_RO(temp2_min_hyst, min_hyst, 0x08);
	static SENSOR_DEVICE_ATTR_RO(temp2_max_hyst, hyst, 0x07);
	static SENSOR_DEVICE_ATTR_RO(temp2_crit_hyst, hyst, 0x19);

	static SENSOR_DEVICE_ATTR_RW(temp3_min, temp, 0x16);
	static SENSOR_DEVICE_ATTR_RW(temp3_max, temp, 0x15);
	static SENSOR_DEVICE_ATTR_RW(temp3_crit, temp, 0x1A);
	static SENSOR_DEVICE_ATTR_RO(temp3_input, temp, 0x23);
	static SENSOR_DEVICE_ATTR_2_RO(temp3_fault, bit, 0x1b, 0x04);
	static SENSOR_DEVICE_ATTR_2_RO(temp3_min_alarm, bit, 0x36, 0x04);
	static SENSOR_DEVICE_ATTR_2_RO(temp3_max_alarm, bit, 0x35, 0x04);
	static SENSOR_DEVICE_ATTR_2_RO(temp3_crit_alarm, bit, 0x37, 0x04);
	static SENSOR_DEVICE_ATTR_RO(temp3_min_hyst, min_hyst, 0x16);
	static SENSOR_DEVICE_ATTR_RO(temp3_max_hyst, hyst, 0x15);
	static SENSOR_DEVICE_ATTR_RO(temp3_crit_hyst, hyst, 0x1A);

	static SENSOR_DEVICE_ATTR_RW(temp4_min, temp, 0x2D);
	static SENSOR_DEVICE_ATTR_RW(temp4_max, temp, 0x2C);
	static SENSOR_DEVICE_ATTR_RW(temp4_crit, temp, 0x30);
	static SENSOR_DEVICE_ATTR_RO(temp4_input, temp, 0x2A);
	static SENSOR_DEVICE_ATTR_2_RO(temp4_fault, bit, 0x1b, 0x08);
	static SENSOR_DEVICE_ATTR_2_RO(temp4_min_alarm, bit, 0x36, 0x08);
	static SENSOR_DEVICE_ATTR_2_RO(temp4_max_alarm, bit, 0x35, 0x08);
	static SENSOR_DEVICE_ATTR_2_RO(temp4_crit_alarm, bit, 0x37, 0x08);
	static SENSOR_DEVICE_ATTR_RO(temp4_min_hyst, min_hyst, 0x2D);
	static SENSOR_DEVICE_ATTR_RO(temp4_max_hyst, hyst, 0x2C);
	static SENSOR_DEVICE_ATTR_RO(temp4_crit_hyst, hyst, 0x30);

	static SENSOR_DEVICE_ATTR_2_RW(power_state, bit, 0x03, 0x40);

	static struct attribute *emc1402_attrs[] = {
	&sensor_dev_attr_temp1_min.dev_attr.attr,
	&sensor_dev_attr_temp1_max.dev_attr.attr,
	&sensor_dev_attr_temp1_crit.dev_attr.attr,
	&sensor_dev_attr_temp1_input.dev_attr.attr,
	&sensor_dev_attr_temp1_min_hyst.dev_attr.attr,
	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
	&sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,

	&sensor_dev_attr_temp2_min.dev_attr.attr,
	&sensor_dev_attr_temp2_max.dev_attr.attr,
	&sensor_dev_attr_temp2_crit.dev_attr.attr,
	&sensor_dev_attr_temp2_input.dev_attr.attr,
	&sensor_dev_attr_temp2_min_hyst.dev_attr.attr,
	&sensor_dev_attr_temp2_max_hyst.dev_attr.attr,
	&sensor_dev_attr_temp2_crit_hyst.dev_attr.attr,

	&sensor_dev_attr_power_state.dev_attr.attr,
	NULL
	};

	static const struct attribute_group emc1402_group = {
	.attrs = emc1402_attrs,
	};

	static struct attribute *emc1403_attrs[] = {
	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,

	&sensor_dev_attr_temp2_fault.dev_attr.attr,
	&sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
	&sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
	&sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,

	&sensor_dev_attr_temp3_min.dev_attr.attr,
	&sensor_dev_attr_temp3_max.dev_attr.attr,
	&sensor_dev_attr_temp3_crit.dev_attr.attr,
	&sensor_dev_attr_temp3_input.dev_attr.attr,
	&sensor_dev_attr_temp3_fault.dev_attr.attr,
	&sensor_dev_attr_temp3_min_alarm.dev_attr.attr,
	&sensor_dev_attr_temp3_max_alarm.dev_attr.attr,
	&sensor_dev_attr_temp3_crit_alarm.dev_attr.attr,
	&sensor_dev_attr_temp3_min_hyst.dev_attr.attr,
	&sensor_dev_attr_temp3_max_hyst.dev_attr.attr,
	&sensor_dev_attr_temp3_crit_hyst.dev_attr.attr,
	NULL
	};

	static const struct attribute_group emc1403_group = {
	.attrs = emc1403_attrs,
	};

	static struct attribute *emc1404_attrs[] = {
	&sensor_dev_attr_temp4_min.dev_attr.attr,
	&sensor_dev_attr_temp4_max.dev_attr.attr,
	&sensor_dev_attr_temp4_crit.dev_attr.attr,
	&sensor_dev_attr_temp4_input.dev_attr.attr,
	&sensor_dev_attr_temp4_fault.dev_attr.attr,
	&sensor_dev_attr_temp4_min_alarm.dev_attr.attr,
	&sensor_dev_attr_temp4_max_alarm.dev_attr.attr,
	&sensor_dev_attr_temp4_crit_alarm.dev_attr.attr,
	&sensor_dev_attr_temp4_min_hyst.dev_attr.attr,
	&sensor_dev_attr_temp4_max_hyst.dev_attr.attr,
	&sensor_dev_attr_temp4_crit_hyst.dev_attr.attr,
	NULL
	};

	static const struct attribute_group emc1404_group = {
	.attrs = emc1404_attrs,
	};

	/*
	* EMC14x2 uses a different register and different bits to report alarm and
	* fault status. For simplicity, provide a separate attribute group for this
	* chip series.
	* Since we can not re-use the same attribute names, create a separate attribute
	* array.
	*/
	static struct sensor_device_attribute_2 emc1402_alarms[] = {
	SENSOR_ATTR_2_RO(temp1_min_alarm, bit, 0x02, 0x20),
	SENSOR_ATTR_2_RO(temp1_max_alarm, bit, 0x02, 0x40),
	SENSOR_ATTR_2_RO(temp1_crit_alarm, bit, 0x02, 0x01),

	SENSOR_ATTR_2_RO(temp2_fault, bit, 0x02, 0x04),
	SENSOR_ATTR_2_RO(temp2_min_alarm, bit, 0x02, 0x08),
	SENSOR_ATTR_2_RO(temp2_max_alarm, bit, 0x02, 0x10),
	SENSOR_ATTR_2_RO(temp2_crit_alarm, bit, 0x02, 0x02),
	};

	static struct attribute *emc1402_alarm_attrs[] = {
	&emc1402_alarms[0].dev_attr.attr,
	&emc1402_alarms[1].dev_attr.attr,
	&emc1402_alarms[2].dev_attr.attr,
	&emc1402_alarms[3].dev_attr.attr,
	&emc1402_alarms[4].dev_attr.attr,
	&emc1402_alarms[5].dev_attr.attr,
	&emc1402_alarms[6].dev_attr.attr,
	NULL,
	};

	static const struct attribute_group emc1402_alarm_group = {
	.attrs = emc1402_alarm_attrs,
	};

	static int emc1403_detect(struct i2c_client *client,
	struct i2c_board_info *info)
	{
	int id;
	/* Check if thermal chip is SMSC and EMC1403 or EMC1423 */

	id = i2c_smbus_read_byte_data(client, THERMAL_SMSC_ID_REG);
	if (id != 0x5d)
	return -ENODEV;

	id = i2c_smbus_read_byte_data(client, THERMAL_PID_REG);
	switch (id) {
	case 0x20:
	strscpy(info->type, "emc1402", I2C_NAME_SIZE);
	break;
	case 0x21:
	strscpy(info->type, "emc1403", I2C_NAME_SIZE);
	break;
	case 0x22:
	strscpy(info->type, "emc1422", I2C_NAME_SIZE);
	break;
	case 0x23:
	strscpy(info->type, "emc1423", I2C_NAME_SIZE);
	break;
	case 0x25:
	strscpy(info->type, "emc1404", I2C_NAME_SIZE);
	break;
	case 0x27:
	strscpy(info->type, "emc1424", I2C_NAME_SIZE);
	break;
	default:
	return -ENODEV;
	}

	id = i2c_smbus_read_byte_data(client, THERMAL_REVISION_REG);
	if (id < 0x01 \|\| id > 0x04)
	return -ENODEV;

	return 0;
	}

	static bool emc1403_regmap_is_volatile(struct device *dev, unsigned int reg)
	{
	switch (reg) {
	case 0x00: /* internal diode high byte */
	case 0x01: /* external diode 1 high byte */
	case 0x02: /* status */
	case 0x10: /* external diode 1 low byte */
	case 0x1b: /* external diode fault */
	case 0x23: /* external diode 2 high byte */
	case 0x24: /* external diode 2 low byte */
	case 0x29: /* internal diode low byte */
	case 0x2a: /* externl diode 3 high byte */
	case 0x2b: /* external diode 3 low byte */
	case 0x35: /* high limit status */
	case 0x36: /* low limit status */
	case 0x37: /* therm limit status */
	return true;
	default:
	return false;
	}
	}

	static const struct regmap_config emc1403_regmap_config = {
	.reg_bits = 8,
	.val_bits = 8,
	.cache_type = REGCACHE_RBTREE,
	.volatile_reg = emc1403_regmap_is_volatile,
	};

	static const struct i2c_device_id emc1403_idtable[];

	static int emc1403_probe(struct i2c_client *client)
	{
	struct thermal_data *data;
	struct device *hwmon_dev;
	const struct i2c_device_id *id = i2c_match_id(emc1403_idtable, client);

	data = devm_kzalloc(&client->dev, sizeof(struct thermal_data),
	GFP_KERNEL);
	if (data == NULL)
	return -ENOMEM;

	data->regmap = devm_regmap_init_i2c(client, &emc1403_regmap_config);
	if (IS_ERR(data->regmap))
	return PTR_ERR(data->regmap);

	mutex_init(&data->mutex);

	switch (id->driver_data) {
	case emc1404:
	data->groups[2] = &emc1404_group;
	fallthrough;
	case emc1403:
	data->groups[1] = &emc1403_group;
	fallthrough;
	case emc1402:
	data->groups[0] = &emc1402_group;
	}

	if (id->driver_data == emc1402)
	data->groups[1] = &emc1402_alarm_group;

	hwmon_dev = devm_hwmon_device_register_with_groups(&client->dev,
	client->name, data,
	data->groups);
	if (IS_ERR(hwmon_dev))
	return PTR_ERR(hwmon_dev);

	dev_info(&client->dev, "%s Thermal chip found\n", id->name);
	return 0;
	}

	static const unsigned short emc1403_address_list[] = {
	0x18, 0x1c, 0x29, 0x4c, 0x4d, 0x5c, I2C_CLIENT_END
	};

	/* Last digit of chip name indicates number of channels */
	static const struct i2c_device_id emc1403_idtable[] = {
	{ "emc1402", emc1402 },
	{ "emc1403", emc1403 },
	{ "emc1404", emc1404 },
	{ "emc1412", emc1402 },
	{ "emc1413", emc1403 },
	{ "emc1414", emc1404 },
	{ "emc1422", emc1402 },
	{ "emc1423", emc1403 },
	{ "emc1424", emc1404 },
	{ }
	};
	MODULE_DEVICE_TABLE(i2c, emc1403_idtable);

	static struct i2c_driver sensor_emc1403 = {
	.class = I2C_CLASS_HWMON,
	.driver = {
	.name = "emc1403",
	},
	.detect = emc1403_detect,
	.probe = emc1403_probe,
	.id_table = emc1403_idtable,
	.address_list = emc1403_address_list,
	};

	module_i2c_driver(sensor_emc1403);

	MODULE_AUTHOR("Kalhan Trisal <kalhan.trisal@intel.com");
	MODULE_DESCRIPTION("emc1403 Thermal Driver");
	MODULE_LICENSE("GPL v2");