drivers/hwmon/jc42.c - kernel/msm-4.9 - Gitiles

 /*
  * jc42.c - driver for Jedec JC42.4 compliant temperature sensors
  *
  * Copyright (c) 2010  Ericsson AB.
  *
  * Derived from lm77.c by Andras BALI <drewie@freemail.hu>.
  *
  * JC42.4 compliant temperature sensors are typically used on memory modules.
  *
  * 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>

 /* Addresses to scan */
 static const unsigned short normal_i2c[] = {
 	0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, I2C_CLIENT_END };

 /* JC42 registers. All registers are 16 bit. */
 #define JC42_REG_CAP		0x00
 #define JC42_REG_CONFIG		0x01
 #define JC42_REG_TEMP_UPPER	0x02
 #define JC42_REG_TEMP_LOWER	0x03
 #define JC42_REG_TEMP_CRITICAL	0x04
 #define JC42_REG_TEMP		0x05
 #define JC42_REG_MANID		0x06
 #define JC42_REG_DEVICEID	0x07

 /* Status bits in temperature register */
 #define JC42_ALARM_CRIT_BIT	15
 #define JC42_ALARM_MAX_BIT	14
 #define JC42_ALARM_MIN_BIT	13

 /* Configuration register defines */
 #define JC42_CFG_CRIT_ONLY	(1 << 2)
 #define JC42_CFG_TCRIT_LOCK	(1 << 6)
 #define JC42_CFG_EVENT_LOCK	(1 << 7)
 #define JC42_CFG_SHUTDOWN	(1 << 8)
 #define JC42_CFG_HYST_SHIFT	9
 #define JC42_CFG_HYST_MASK	0x03

 /* Capabilities */
 #define JC42_CAP_RANGE		(1 << 2)

 /* Manufacturer IDs */
 #define ADT_MANID		0x11d4  /* Analog Devices */
 #define MAX_MANID		0x004d  /* Maxim */
 #define IDT_MANID		0x00b3  /* IDT */
 #define MCP_MANID		0x0054  /* Microchip */
 #define NXP_MANID		0x1131  /* NXP Semiconductors */
 #define ONS_MANID		0x1b09  /* ON Semiconductor */
 #define STM_MANID		0x104a  /* ST Microelectronics */

 /* Supported chips */

 /* Analog Devices */
 #define ADT7408_DEVID		0x0801
 #define ADT7408_DEVID_MASK	0xffff

 /* IDT */
 #define TS3000B3_DEVID		0x2903  /* Also matches TSE2002B3 */
 #define TS3000B3_DEVID_MASK	0xffff

 /* Maxim */
 #define MAX6604_DEVID		0x3e00
 #define MAX6604_DEVID_MASK	0xffff

 /* Microchip */
 #define MCP98242_DEVID		0x2000
 #define MCP98242_DEVID_MASK	0xfffc

 #define MCP98243_DEVID		0x2100
 #define MCP98243_DEVID_MASK	0xfffc

 #define MCP9843_DEVID		0x0000	/* Also matches mcp9805 */
 #define MCP9843_DEVID_MASK	0xfffe

 /* NXP */
 #define SE97_DEVID		0xa200
 #define SE97_DEVID_MASK		0xfffc

 #define SE98_DEVID		0xa100
 #define SE98_DEVID_MASK		0xfffc

 /* ON Semiconductor */
 #define CAT6095_DEVID		0x0800	/* Also matches CAT34TS02 */
 #define CAT6095_DEVID_MASK	0xffe0

 /* ST Microelectronics */
 #define STTS424_DEVID		0x0101
 #define STTS424_DEVID_MASK	0xffff

 #define STTS424E_DEVID		0x0000
 #define STTS424E_DEVID_MASK	0xfffe

 static u16 jc42_hysteresis[] = { 0, 1500, 3000, 6000 };

 struct jc42_chips {
 	u16 manid;
 	u16 devid;
 	u16 devid_mask;
 };

 static struct jc42_chips jc42_chips[] = {
 	{ ADT_MANID, ADT7408_DEVID, ADT7408_DEVID_MASK },
 	{ IDT_MANID, TS3000B3_DEVID, TS3000B3_DEVID_MASK },
 	{ MAX_MANID, MAX6604_DEVID, MAX6604_DEVID_MASK },
 	{ MCP_MANID, MCP98242_DEVID, MCP98242_DEVID_MASK },
 	{ MCP_MANID, MCP98243_DEVID, MCP98243_DEVID_MASK },
 	{ MCP_MANID, MCP9843_DEVID, MCP9843_DEVID_MASK },
 	{ NXP_MANID, SE97_DEVID, SE97_DEVID_MASK },
 	{ ONS_MANID, CAT6095_DEVID, CAT6095_DEVID_MASK },
 	{ NXP_MANID, SE98_DEVID, SE98_DEVID_MASK },
 	{ STM_MANID, STTS424_DEVID, STTS424_DEVID_MASK },
 	{ STM_MANID, STTS424E_DEVID, STTS424E_DEVID_MASK },
 };

 /* Each client has this additional data */
 struct jc42_data {
 	struct device	*hwmon_dev;
 	struct mutex	update_lock;	/* protect register access */
 	bool		extended;	/* true if extended range supported */
 	bool		valid;
 	unsigned long	last_updated;	/* In jiffies */
 	u16		orig_config;	/* original configuration */
 	u16		config;		/* current configuration */
 	u16		temp_input;	/* Temperatures */
 	u16		temp_crit;
 	u16		temp_min;
 	u16		temp_max;
 };

 static int jc42_probe(struct i2c_client *client,
 		      const struct i2c_device_id *id);
 static int jc42_detect(struct i2c_client *client, struct i2c_board_info *info);
 static int jc42_remove(struct i2c_client *client);

 static struct jc42_data *jc42_update_device(struct device *dev);

 static const struct i2c_device_id jc42_id[] = {
 	{ "adt7408", 0 },
 	{ "cat94ts02", 0 },
 	{ "cat6095", 0 },
 	{ "jc42", 0 },
 	{ "max6604", 0 },
 	{ "mcp9805", 0 },
 	{ "mcp98242", 0 },
 	{ "mcp98243", 0 },
 	{ "mcp9843", 0 },
 	{ "se97", 0 },
 	{ "se97b", 0 },
 	{ "se98", 0 },
 	{ "stts424", 0 },
 	{ "tse2002b3", 0 },
 	{ "ts3000b3", 0 },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, jc42_id);

 #ifdef CONFIG_PM

 static int jc42_suspend(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct jc42_data *data = i2c_get_clientdata(client);

 	data->config |= JC42_CFG_SHUTDOWN;
 	i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG, data->config);
 	return 0;
 }

 static int jc42_resume(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct jc42_data *data = i2c_get_clientdata(client);

 	data->config &= ~JC42_CFG_SHUTDOWN;
 	i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG, data->config);
 	return 0;
 }

 static const struct dev_pm_ops jc42_dev_pm_ops = {
 	.suspend = jc42_suspend,
 	.resume = jc42_resume,
 };

 #define JC42_DEV_PM_OPS (&jc42_dev_pm_ops)
 #else
 #define JC42_DEV_PM_OPS NULL
 #endif /* CONFIG_PM */

 /* This is the driver that will be inserted */
 static struct i2c_driver jc42_driver = {
 	.class		= I2C_CLASS_SPD,
 	.driver = {
 		.name	= "jc42",
 		.pm = JC42_DEV_PM_OPS,
 	},
 	.probe		= jc42_probe,
 	.remove		= jc42_remove,
 	.id_table	= jc42_id,
 	.detect		= jc42_detect,
 	.address_list	= normal_i2c,
 };

 #define JC42_TEMP_MIN_EXTENDED	(-40000)
 #define JC42_TEMP_MIN		0
 #define JC42_TEMP_MAX		125000

 static u16 jc42_temp_to_reg(int temp, bool extended)
 {
 	int ntemp = SENSORS_LIMIT(temp,
 				  extended ? JC42_TEMP_MIN_EXTENDED :
 				  JC42_TEMP_MIN, JC42_TEMP_MAX);

 	/* convert from 0.001 to 0.0625 resolution */
 	return (ntemp * 2 / 125) & 0x1fff;
 }

 static int jc42_temp_from_reg(s16 reg)
 {
 	reg &= 0x1fff;

 	/* sign extend register */
 	if (reg & 0x1000)
 		reg |= 0xf000;

 	/* convert from 0.0625 to 0.001 resolution */
 	return reg * 125 / 2;
 }

 /* sysfs stuff */

 /* read routines for temperature limits */
 #define show(value)	\
 static ssize_t show_##value(struct device *dev,				\
 			    struct device_attribute *attr,		\
 			    char *buf)					\
 {									\
 	struct jc42_data *data = jc42_update_device(dev);		\
 	if (IS_ERR(data))						\
 		return PTR_ERR(data);					\
 	return sprintf(buf, "%d\n", jc42_temp_from_reg(data->value));	\
 }

 show(temp_input);
 show(temp_crit);
 show(temp_min);
 show(temp_max);

 /* read routines for hysteresis values */
 static ssize_t show_temp_crit_hyst(struct device *dev,
 				   struct device_attribute *attr, char *buf)
 {
 	struct jc42_data *data = jc42_update_device(dev);
 	int temp, hyst;

 	if (IS_ERR(data))
 		return PTR_ERR(data);

 	temp = jc42_temp_from_reg(data->temp_crit);
 	hyst = jc42_hysteresis[(data->config >> JC42_CFG_HYST_SHIFT)
 			       & JC42_CFG_HYST_MASK];
 	return sprintf(buf, "%d\n", temp - hyst);
 }

 static ssize_t show_temp_max_hyst(struct device *dev,
 				  struct device_attribute *attr, char *buf)
 {
 	struct jc42_data *data = jc42_update_device(dev);
 	int temp, hyst;

 	if (IS_ERR(data))
 		return PTR_ERR(data);

 	temp = jc42_temp_from_reg(data->temp_max);
 	hyst = jc42_hysteresis[(data->config >> JC42_CFG_HYST_SHIFT)
 			       & JC42_CFG_HYST_MASK];
 	return sprintf(buf, "%d\n", temp - hyst);
 }

 /* write routines */
 #define set(value, reg)	\
 static ssize_t set_##value(struct device *dev,				\
 			   struct device_attribute *attr,		\
 			   const char *buf, size_t count)		\
 {									\
 	struct i2c_client *client = to_i2c_client(dev);			\
 	struct jc42_data *data = i2c_get_clientdata(client);		\
 	int err, ret = count;						\
 	long val;							\
 	if (kstrtol(buf, 10, &val) < 0)				\
 		return -EINVAL;						\
 	mutex_lock(&data->update_lock);					\
 	data->value = jc42_temp_to_reg(val, data->extended);		\
 	err = i2c_smbus_write_word_swapped(client, reg, data->value);	\
 	if (err < 0)							\
 		ret = err;						\
 	mutex_unlock(&data->update_lock);				\
 	return ret;							\
 }

 set(temp_min, JC42_REG_TEMP_LOWER);
 set(temp_max, JC42_REG_TEMP_UPPER);
 set(temp_crit, JC42_REG_TEMP_CRITICAL);

 /* JC42.4 compliant chips only support four hysteresis values.
  * Pick best choice and go from there. */
 static ssize_t set_temp_crit_hyst(struct device *dev,
 				  struct device_attribute *attr,
 				  const char *buf, size_t count)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct jc42_data *data = i2c_get_clientdata(client);
 	unsigned long val;
 	int diff, hyst;
 	int err;
 	int ret = count;

 	if (kstrtoul(buf, 10, &val) < 0)
 		return -EINVAL;

 	diff = jc42_temp_from_reg(data->temp_crit) - val;
 	hyst = 0;
 	if (diff > 0) {
 		if (diff < 2250)
 			hyst = 1;	/* 1.5 degrees C */
 		else if (diff < 4500)
 			hyst = 2;	/* 3.0 degrees C */
 		else
 			hyst = 3;	/* 6.0 degrees C */
 	}

 	mutex_lock(&data->update_lock);
 	data->config = (data->config
 			& ~(JC42_CFG_HYST_MASK << JC42_CFG_HYST_SHIFT))
 	  | (hyst << JC42_CFG_HYST_SHIFT);
 	err = i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG,
 					   data->config);
 	if (err < 0)
 		ret = err;
 	mutex_unlock(&data->update_lock);
 	return ret;
 }

 static ssize_t show_alarm(struct device *dev,
 			  struct device_attribute *attr, char *buf)
 {
 	u16 bit = to_sensor_dev_attr(attr)->index;
 	struct jc42_data *data = jc42_update_device(dev);
 	u16 val;

 	if (IS_ERR(data))
 		return PTR_ERR(data);

 	val = data->temp_input;
 	if (bit != JC42_ALARM_CRIT_BIT && (data->config & JC42_CFG_CRIT_ONLY))
 		val = 0;
 	return sprintf(buf, "%u\n", (val >> bit) & 1);
 }

 static DEVICE_ATTR(temp1_input, S_IRUGO,
 		   show_temp_input, NULL);
 static DEVICE_ATTR(temp1_crit, S_IRUGO,
 		   show_temp_crit, set_temp_crit);
 static DEVICE_ATTR(temp1_min, S_IRUGO,
 		   show_temp_min, set_temp_min);
 static DEVICE_ATTR(temp1_max, S_IRUGO,
 		   show_temp_max, set_temp_max);

 static DEVICE_ATTR(temp1_crit_hyst, S_IRUGO,
 		   show_temp_crit_hyst, set_temp_crit_hyst);
 static DEVICE_ATTR(temp1_max_hyst, S_IRUGO,
 		   show_temp_max_hyst, NULL);

 static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL,
 			  JC42_ALARM_CRIT_BIT);
 static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL,
 			  JC42_ALARM_MIN_BIT);
 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL,
 			  JC42_ALARM_MAX_BIT);

 static struct attribute *jc42_attributes[] = {
 	&dev_attr_temp1_input.attr,
 	&dev_attr_temp1_crit.attr,
 	&dev_attr_temp1_min.attr,
 	&dev_attr_temp1_max.attr,
 	&dev_attr_temp1_crit_hyst.attr,
 	&dev_attr_temp1_max_hyst.attr,
 	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
 	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
 	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
 	NULL
 };

 static umode_t jc42_attribute_mode(struct kobject *kobj,
 				  struct attribute *attr, int index)
 {
 	struct device *dev = container_of(kobj, struct device, kobj);
 	struct i2c_client *client = to_i2c_client(dev);
 	struct jc42_data *data = i2c_get_clientdata(client);
 	unsigned int config = data->config;
 	bool readonly;

 	if (attr == &dev_attr_temp1_crit.attr)
 		readonly = config & JC42_CFG_TCRIT_LOCK;
 	else if (attr == &dev_attr_temp1_min.attr ||
 		 attr == &dev_attr_temp1_max.attr)
 		readonly = config & JC42_CFG_EVENT_LOCK;
 	else if (attr == &dev_attr_temp1_crit_hyst.attr)
 		readonly = config & (JC42_CFG_EVENT_LOCK | JC42_CFG_TCRIT_LOCK);
 	else
 		readonly = true;

 	return S_IRUGO | (readonly ? 0 : S_IWUSR);
 }

 static const struct attribute_group jc42_group = {
 	.attrs = jc42_attributes,
 	.is_visible = jc42_attribute_mode,
 };

 /* Return 0 if detection is successful, -ENODEV otherwise */
 static int jc42_detect(struct i2c_client *new_client,
 		       struct i2c_board_info *info)
 {
 	struct i2c_adapter *adapter = new_client->adapter;
 	int i, config, cap, manid, devid;

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

 	cap = i2c_smbus_read_word_swapped(new_client, JC42_REG_CAP);
 	config = i2c_smbus_read_word_swapped(new_client, JC42_REG_CONFIG);
 	manid = i2c_smbus_read_word_swapped(new_client, JC42_REG_MANID);
 	devid = i2c_smbus_read_word_swapped(new_client, JC42_REG_DEVICEID);

 	if (cap < 0 || config < 0 || manid < 0 || devid < 0)
 		return -ENODEV;

 	if ((cap & 0xff00) || (config & 0xf800))
 		return -ENODEV;

 	for (i = 0; i < ARRAY_SIZE(jc42_chips); i++) {
 		struct jc42_chips *chip = &jc42_chips[i];
 		if (manid == chip->manid &&
 		    (devid & chip->devid_mask) == chip->devid) {
 			strlcpy(info->type, "jc42", I2C_NAME_SIZE);
 			return 0;
 		}
 	}
 	return -ENODEV;
 }

 static int jc42_probe(struct i2c_client *new_client,
 		      const struct i2c_device_id *id)
 {
 	struct jc42_data *data;
 	int config, cap, err;

 	data = kzalloc(sizeof(struct jc42_data), GFP_KERNEL);
 	if (!data) {
 		err = -ENOMEM;
 		goto exit;
 	}

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

 	cap = i2c_smbus_read_word_swapped(new_client, JC42_REG_CAP);
 	if (cap < 0) {
 		err = -EINVAL;
 		goto exit_free;
 	}
 	data->extended = !!(cap & JC42_CAP_RANGE);

 	config = i2c_smbus_read_word_swapped(new_client, JC42_REG_CONFIG);
 	if (config < 0) {
 		err = -EINVAL;
 		goto exit_free;
 	}
 	data->orig_config = config;
 	if (config & JC42_CFG_SHUTDOWN) {
 		config &= ~JC42_CFG_SHUTDOWN;
 		i2c_smbus_write_word_swapped(new_client, JC42_REG_CONFIG,
 					     config);
 	}
 	data->config = config;

 	/* Register sysfs hooks */
 	err = sysfs_create_group(&new_client->dev.kobj, &jc42_group);
 	if (err)
 		goto exit_free;

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

 	return 0;

 exit_remove:
 	sysfs_remove_group(&new_client->dev.kobj, &jc42_group);
 exit_free:
 	kfree(data);
 exit:
 	return err;
 }

 static int jc42_remove(struct i2c_client *client)
 {
 	struct jc42_data *data = i2c_get_clientdata(client);
 	hwmon_device_unregister(data->hwmon_dev);
 	sysfs_remove_group(&client->dev.kobj, &jc42_group);
 	if (data->config != data->orig_config)
 		i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG,
 					     data->orig_config);
 	kfree(data);
 	return 0;
 }

 static struct jc42_data *jc42_update_device(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct jc42_data *data = i2c_get_clientdata(client);
 	struct jc42_data *ret = data;
 	int val;

 	mutex_lock(&data->update_lock);

 	if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
 		val = i2c_smbus_read_word_swapped(client, JC42_REG_TEMP);
 		if (val < 0) {
 			ret = ERR_PTR(val);
 			goto abort;
 		}
 		data->temp_input = val;

 		val = i2c_smbus_read_word_swapped(client,
 						  JC42_REG_TEMP_CRITICAL);
 		if (val < 0) {
 			ret = ERR_PTR(val);
 			goto abort;
 		}
 		data->temp_crit = val;

 		val = i2c_smbus_read_word_swapped(client, JC42_REG_TEMP_LOWER);
 		if (val < 0) {
 			ret = ERR_PTR(val);
 			goto abort;
 		}
 		data->temp_min = val;

 		val = i2c_smbus_read_word_swapped(client, JC42_REG_TEMP_UPPER);
 		if (val < 0) {
 			ret = ERR_PTR(val);
 			goto abort;
 		}
 		data->temp_max = val;

 		data->last_updated = jiffies;
 		data->valid = true;
 	}
 abort:
 	mutex_unlock(&data->update_lock);
 	return ret;
 }

 static int __init sensors_jc42_init(void)
 {
 	return i2c_add_driver(&jc42_driver);
 }

 static void __exit sensors_jc42_exit(void)
 {
 	i2c_del_driver(&jc42_driver);
 }

 MODULE_AUTHOR("Guenter Roeck <guenter.roeck@ericsson.com>");
 MODULE_DESCRIPTION("JC42 driver");
 MODULE_LICENSE("GPL");

 module_init(sensors_jc42_init);
 module_exit(sensors_jc42_exit);
	/*
	* jc42.c - driver for Jedec JC42.4 compliant temperature sensors
	*
	* Copyright (c) 2010 Ericsson AB.
	*
	* Derived from lm77.c by Andras BALI <drewie@freemail.hu>.
	*
	* JC42.4 compliant temperature sensors are typically used on memory modules.
	*
	* 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>

	/* Addresses to scan */
	static const unsigned short normal_i2c[] = {
	0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, I2C_CLIENT_END };

	/* JC42 registers. All registers are 16 bit. */
	#define JC42_REG_CAP 0x00
	#define JC42_REG_CONFIG 0x01
	#define JC42_REG_TEMP_UPPER 0x02
	#define JC42_REG_TEMP_LOWER 0x03
	#define JC42_REG_TEMP_CRITICAL 0x04
	#define JC42_REG_TEMP 0x05
	#define JC42_REG_MANID 0x06
	#define JC42_REG_DEVICEID 0x07

	/* Status bits in temperature register */
	#define JC42_ALARM_CRIT_BIT 15
	#define JC42_ALARM_MAX_BIT 14
	#define JC42_ALARM_MIN_BIT 13

	/* Configuration register defines */
	#define JC42_CFG_CRIT_ONLY (1 << 2)
	#define JC42_CFG_TCRIT_LOCK (1 << 6)
	#define JC42_CFG_EVENT_LOCK (1 << 7)
	#define JC42_CFG_SHUTDOWN (1 << 8)
	#define JC42_CFG_HYST_SHIFT 9
	#define JC42_CFG_HYST_MASK 0x03

	/* Capabilities */
	#define JC42_CAP_RANGE (1 << 2)

	/* Manufacturer IDs */
	#define ADT_MANID 0x11d4 /* Analog Devices */
	#define MAX_MANID 0x004d /* Maxim */
	#define IDT_MANID 0x00b3 /* IDT */
	#define MCP_MANID 0x0054 /* Microchip */
	#define NXP_MANID 0x1131 /* NXP Semiconductors */
	#define ONS_MANID 0x1b09 /* ON Semiconductor */
	#define STM_MANID 0x104a /* ST Microelectronics */

	/* Supported chips */

	/* Analog Devices */
	#define ADT7408_DEVID 0x0801
	#define ADT7408_DEVID_MASK 0xffff

	/* IDT */
	#define TS3000B3_DEVID 0x2903 /* Also matches TSE2002B3 */
	#define TS3000B3_DEVID_MASK 0xffff

	/* Maxim */
	#define MAX6604_DEVID 0x3e00
	#define MAX6604_DEVID_MASK 0xffff

	/* Microchip */
	#define MCP98242_DEVID 0x2000
	#define MCP98242_DEVID_MASK 0xfffc

	#define MCP98243_DEVID 0x2100
	#define MCP98243_DEVID_MASK 0xfffc

	#define MCP9843_DEVID 0x0000 /* Also matches mcp9805 */
	#define MCP9843_DEVID_MASK 0xfffe

	/* NXP */
	#define SE97_DEVID 0xa200
	#define SE97_DEVID_MASK 0xfffc

	#define SE98_DEVID 0xa100
	#define SE98_DEVID_MASK 0xfffc

	/* ON Semiconductor */
	#define CAT6095_DEVID 0x0800 /* Also matches CAT34TS02 */
	#define CAT6095_DEVID_MASK 0xffe0

	/* ST Microelectronics */
	#define STTS424_DEVID 0x0101
	#define STTS424_DEVID_MASK 0xffff

	#define STTS424E_DEVID 0x0000
	#define STTS424E_DEVID_MASK 0xfffe

	static u16 jc42_hysteresis[] = { 0, 1500, 3000, 6000 };

	struct jc42_chips {
	u16 manid;
	u16 devid;
	u16 devid_mask;
	};

	static struct jc42_chips jc42_chips[] = {
	{ ADT_MANID, ADT7408_DEVID, ADT7408_DEVID_MASK },
	{ IDT_MANID, TS3000B3_DEVID, TS3000B3_DEVID_MASK },
	{ MAX_MANID, MAX6604_DEVID, MAX6604_DEVID_MASK },
	{ MCP_MANID, MCP98242_DEVID, MCP98242_DEVID_MASK },
	{ MCP_MANID, MCP98243_DEVID, MCP98243_DEVID_MASK },
	{ MCP_MANID, MCP9843_DEVID, MCP9843_DEVID_MASK },
	{ NXP_MANID, SE97_DEVID, SE97_DEVID_MASK },
	{ ONS_MANID, CAT6095_DEVID, CAT6095_DEVID_MASK },
	{ NXP_MANID, SE98_DEVID, SE98_DEVID_MASK },
	{ STM_MANID, STTS424_DEVID, STTS424_DEVID_MASK },
	{ STM_MANID, STTS424E_DEVID, STTS424E_DEVID_MASK },
	};

	/* Each client has this additional data */
	struct jc42_data {
	struct device *hwmon_dev;
	struct mutex update_lock; /* protect register access */
	bool extended; /* true if extended range supported */
	bool valid;
	unsigned long last_updated; /* In jiffies */
	u16 orig_config; /* original configuration */
	u16 config; /* current configuration */
	u16 temp_input; /* Temperatures */
	u16 temp_crit;
	u16 temp_min;
	u16 temp_max;
	};

	static int jc42_probe(struct i2c_client *client,
	const struct i2c_device_id *id);
	static int jc42_detect(struct i2c_client client, struct i2c_board_info info);
	static int jc42_remove(struct i2c_client *client);

	static struct jc42_data jc42_update_device(struct device dev);

	static const struct i2c_device_id jc42_id[] = {
	{ "adt7408", 0 },
	{ "cat94ts02", 0 },
	{ "cat6095", 0 },
	{ "jc42", 0 },
	{ "max6604", 0 },
	{ "mcp9805", 0 },
	{ "mcp98242", 0 },
	{ "mcp98243", 0 },
	{ "mcp9843", 0 },
	{ "se97", 0 },
	{ "se97b", 0 },
	{ "se98", 0 },
	{ "stts424", 0 },
	{ "tse2002b3", 0 },
	{ "ts3000b3", 0 },
	{ }
	};
	MODULE_DEVICE_TABLE(i2c, jc42_id);

	#ifdef CONFIG_PM

	static int jc42_suspend(struct device *dev)
	{
	struct i2c_client *client = to_i2c_client(dev);
	struct jc42_data *data = i2c_get_clientdata(client);

	data->config \|= JC42_CFG_SHUTDOWN;
	i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG, data->config);
	return 0;
	}

	static int jc42_resume(struct device *dev)
	{
	struct i2c_client *client = to_i2c_client(dev);
	struct jc42_data *data = i2c_get_clientdata(client);

	data->config &= ~JC42_CFG_SHUTDOWN;
	i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG, data->config);
	return 0;
	}

	static const struct dev_pm_ops jc42_dev_pm_ops = {
	.suspend = jc42_suspend,
	.resume = jc42_resume,
	};

	#define JC42_DEV_PM_OPS (&jc42_dev_pm_ops)
	#else
	#define JC42_DEV_PM_OPS NULL
	#endif /* CONFIG_PM */

	/* This is the driver that will be inserted */
	static struct i2c_driver jc42_driver = {
	.class = I2C_CLASS_SPD,
	.driver = {
	.name = "jc42",
	.pm = JC42_DEV_PM_OPS,
	},
	.probe = jc42_probe,
	.remove = jc42_remove,
	.id_table = jc42_id,
	.detect = jc42_detect,
	.address_list = normal_i2c,
	};

	#define JC42_TEMP_MIN_EXTENDED (-40000)
	#define JC42_TEMP_MIN 0
	#define JC42_TEMP_MAX 125000

	static u16 jc42_temp_to_reg(int temp, bool extended)
	{
	int ntemp = SENSORS_LIMIT(temp,
	extended ? JC42_TEMP_MIN_EXTENDED :
	JC42_TEMP_MIN, JC42_TEMP_MAX);

	/* convert from 0.001 to 0.0625 resolution */
	return (ntemp * 2 / 125) & 0x1fff;
	}

	static int jc42_temp_from_reg(s16 reg)
	{
	reg &= 0x1fff;

	/* sign extend register */
	if (reg & 0x1000)
	reg \|= 0xf000;

	/* convert from 0.0625 to 0.001 resolution */
	return reg * 125 / 2;
	}

	/* sysfs stuff */

	/* read routines for temperature limits */
	#define show(value) \
	static ssize_t show_##value(struct device *dev, \
	struct device_attribute *attr, \
	char *buf) \
	{ \
	struct jc42_data *data = jc42_update_device(dev); \
	if (IS_ERR(data)) \
	return PTR_ERR(data); \
	return sprintf(buf, "%d\n", jc42_temp_from_reg(data->value)); \
	}

	show(temp_input);
	show(temp_crit);
	show(temp_min);
	show(temp_max);

	/* read routines for hysteresis values */
	static ssize_t show_temp_crit_hyst(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct jc42_data *data = jc42_update_device(dev);
	int temp, hyst;

	if (IS_ERR(data))
	return PTR_ERR(data);

	temp = jc42_temp_from_reg(data->temp_crit);
	hyst = jc42_hysteresis[(data->config >> JC42_CFG_HYST_SHIFT)
	& JC42_CFG_HYST_MASK];
	return sprintf(buf, "%d\n", temp - hyst);
	}

	static ssize_t show_temp_max_hyst(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct jc42_data *data = jc42_update_device(dev);
	int temp, hyst;

	if (IS_ERR(data))
	return PTR_ERR(data);

	temp = jc42_temp_from_reg(data->temp_max);
	hyst = jc42_hysteresis[(data->config >> JC42_CFG_HYST_SHIFT)
	& JC42_CFG_HYST_MASK];
	return sprintf(buf, "%d\n", temp - hyst);
	}

	/* write routines */
	#define set(value, reg) \
	static ssize_t set_##value(struct device *dev, \
	struct device_attribute *attr, \
	const char *buf, size_t count) \
	{ \
	struct i2c_client *client = to_i2c_client(dev); \
	struct jc42_data *data = i2c_get_clientdata(client); \
	int err, ret = count; \
	long val; \
	if (kstrtol(buf, 10, &val) < 0) \
	return -EINVAL; \
	mutex_lock(&data->update_lock); \
	data->value = jc42_temp_to_reg(val, data->extended); \
	err = i2c_smbus_write_word_swapped(client, reg, data->value); \
	if (err < 0) \
	ret = err; \
	mutex_unlock(&data->update_lock); \
	return ret; \
	}

	set(temp_min, JC42_REG_TEMP_LOWER);
	set(temp_max, JC42_REG_TEMP_UPPER);
	set(temp_crit, JC42_REG_TEMP_CRITICAL);

	/* JC42.4 compliant chips only support four hysteresis values.
	* Pick best choice and go from there. */
	static ssize_t set_temp_crit_hyst(struct device *dev,
	struct device_attribute *attr,
	const char *buf, size_t count)
	{
	struct i2c_client *client = to_i2c_client(dev);
	struct jc42_data *data = i2c_get_clientdata(client);
	unsigned long val;
	int diff, hyst;
	int err;
	int ret = count;

	if (kstrtoul(buf, 10, &val) < 0)
	return -EINVAL;

	diff = jc42_temp_from_reg(data->temp_crit) - val;
	hyst = 0;
	if (diff > 0) {
	if (diff < 2250)
	hyst = 1; /* 1.5 degrees C */
	else if (diff < 4500)
	hyst = 2; /* 3.0 degrees C */
	else
	hyst = 3; /* 6.0 degrees C */
	}

	mutex_lock(&data->update_lock);
	data->config = (data->config
	& ~(JC42_CFG_HYST_MASK << JC42_CFG_HYST_SHIFT))
	\| (hyst << JC42_CFG_HYST_SHIFT);
	err = i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG,
	data->config);
	if (err < 0)
	ret = err;
	mutex_unlock(&data->update_lock);
	return ret;
	}

	static ssize_t show_alarm(struct device *dev,
	struct device_attribute attr, char buf)
	{
	u16 bit = to_sensor_dev_attr(attr)->index;
	struct jc42_data *data = jc42_update_device(dev);
	u16 val;

	if (IS_ERR(data))
	return PTR_ERR(data);

	val = data->temp_input;
	if (bit != JC42_ALARM_CRIT_BIT && (data->config & JC42_CFG_CRIT_ONLY))
	val = 0;
	return sprintf(buf, "%u\n", (val >> bit) & 1);
	}

	static DEVICE_ATTR(temp1_input, S_IRUGO,
	show_temp_input, NULL);
	static DEVICE_ATTR(temp1_crit, S_IRUGO,
	show_temp_crit, set_temp_crit);
	static DEVICE_ATTR(temp1_min, S_IRUGO,
	show_temp_min, set_temp_min);
	static DEVICE_ATTR(temp1_max, S_IRUGO,
	show_temp_max, set_temp_max);

	static DEVICE_ATTR(temp1_crit_hyst, S_IRUGO,
	show_temp_crit_hyst, set_temp_crit_hyst);
	static DEVICE_ATTR(temp1_max_hyst, S_IRUGO,
	show_temp_max_hyst, NULL);

	static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL,
	JC42_ALARM_CRIT_BIT);
	static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL,
	JC42_ALARM_MIN_BIT);
	static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL,
	JC42_ALARM_MAX_BIT);

	static struct attribute *jc42_attributes[] = {
	&dev_attr_temp1_input.attr,
	&dev_attr_temp1_crit.attr,
	&dev_attr_temp1_min.attr,
	&dev_attr_temp1_max.attr,
	&dev_attr_temp1_crit_hyst.attr,
	&dev_attr_temp1_max_hyst.attr,
	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
	NULL
	};

	static umode_t jc42_attribute_mode(struct kobject *kobj,
	struct attribute *attr, int index)
	{
	struct device *dev = container_of(kobj, struct device, kobj);
	struct i2c_client *client = to_i2c_client(dev);
	struct jc42_data *data = i2c_get_clientdata(client);
	unsigned int config = data->config;
	bool readonly;

	if (attr == &dev_attr_temp1_crit.attr)
	readonly = config & JC42_CFG_TCRIT_LOCK;
	else if (attr == &dev_attr_temp1_min.attr \|\|
	attr == &dev_attr_temp1_max.attr)
	readonly = config & JC42_CFG_EVENT_LOCK;
	else if (attr == &dev_attr_temp1_crit_hyst.attr)
	readonly = config & (JC42_CFG_EVENT_LOCK \| JC42_CFG_TCRIT_LOCK);
	else
	readonly = true;

	return S_IRUGO \| (readonly ? 0 : S_IWUSR);
	}

	static const struct attribute_group jc42_group = {
	.attrs = jc42_attributes,
	.is_visible = jc42_attribute_mode,
	};

	/* Return 0 if detection is successful, -ENODEV otherwise */
	static int jc42_detect(struct i2c_client *new_client,
	struct i2c_board_info *info)
	{
	struct i2c_adapter *adapter = new_client->adapter;
	int i, config, cap, manid, devid;

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

	cap = i2c_smbus_read_word_swapped(new_client, JC42_REG_CAP);
	config = i2c_smbus_read_word_swapped(new_client, JC42_REG_CONFIG);
	manid = i2c_smbus_read_word_swapped(new_client, JC42_REG_MANID);
	devid = i2c_smbus_read_word_swapped(new_client, JC42_REG_DEVICEID);

	if (cap < 0 \|\| config < 0 \|\| manid < 0 \|\| devid < 0)
	return -ENODEV;

	if ((cap & 0xff00) \|\| (config & 0xf800))
	return -ENODEV;

	for (i = 0; i < ARRAY_SIZE(jc42_chips); i++) {
	struct jc42_chips *chip = &jc42_chips[i];
	if (manid == chip->manid &&
	(devid & chip->devid_mask) == chip->devid) {
	strlcpy(info->type, "jc42", I2C_NAME_SIZE);
	return 0;
	}
	}
	return -ENODEV;
	}

	static int jc42_probe(struct i2c_client *new_client,
	const struct i2c_device_id *id)
	{
	struct jc42_data *data;
	int config, cap, err;

	data = kzalloc(sizeof(struct jc42_data), GFP_KERNEL);
	if (!data) {
	err = -ENOMEM;
	goto exit;
	}

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

	cap = i2c_smbus_read_word_swapped(new_client, JC42_REG_CAP);
	if (cap < 0) {
	err = -EINVAL;
	goto exit_free;
	}
	data->extended = !!(cap & JC42_CAP_RANGE);

	config = i2c_smbus_read_word_swapped(new_client, JC42_REG_CONFIG);
	if (config < 0) {
	err = -EINVAL;
	goto exit_free;
	}
	data->orig_config = config;
	if (config & JC42_CFG_SHUTDOWN) {
	config &= ~JC42_CFG_SHUTDOWN;
	i2c_smbus_write_word_swapped(new_client, JC42_REG_CONFIG,
	config);
	}
	data->config = config;

	/* Register sysfs hooks */
	err = sysfs_create_group(&new_client->dev.kobj, &jc42_group);
	if (err)
	goto exit_free;

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

	return 0;

	exit_remove:
	sysfs_remove_group(&new_client->dev.kobj, &jc42_group);
	exit_free:
	kfree(data);
	exit:
	return err;
	}

	static int jc42_remove(struct i2c_client *client)
	{
	struct jc42_data *data = i2c_get_clientdata(client);
	hwmon_device_unregister(data->hwmon_dev);
	sysfs_remove_group(&client->dev.kobj, &jc42_group);
	if (data->config != data->orig_config)
	i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG,
	data->orig_config);
	kfree(data);
	return 0;
	}

	static struct jc42_data jc42_update_device(struct device dev)
	{
	struct i2c_client *client = to_i2c_client(dev);
	struct jc42_data *data = i2c_get_clientdata(client);
	struct jc42_data *ret = data;
	int val;

	mutex_lock(&data->update_lock);

	if (time_after(jiffies, data->last_updated + HZ) \|\| !data->valid) {
	val = i2c_smbus_read_word_swapped(client, JC42_REG_TEMP);
	if (val < 0) {
	ret = ERR_PTR(val);
	goto abort;
	}
	data->temp_input = val;

	val = i2c_smbus_read_word_swapped(client,
	JC42_REG_TEMP_CRITICAL);
	if (val < 0) {
	ret = ERR_PTR(val);
	goto abort;
	}
	data->temp_crit = val;

	val = i2c_smbus_read_word_swapped(client, JC42_REG_TEMP_LOWER);
	if (val < 0) {
	ret = ERR_PTR(val);
	goto abort;
	}
	data->temp_min = val;

	val = i2c_smbus_read_word_swapped(client, JC42_REG_TEMP_UPPER);
	if (val < 0) {
	ret = ERR_PTR(val);
	goto abort;
	}
	data->temp_max = val;

	data->last_updated = jiffies;
	data->valid = true;
	}
	abort:
	mutex_unlock(&data->update_lock);
	return ret;
	}

	static int __init sensors_jc42_init(void)
	{
	return i2c_add_driver(&jc42_driver);
	}

	static void __exit sensors_jc42_exit(void)
	{
	i2c_del_driver(&jc42_driver);
	}

	MODULE_AUTHOR("Guenter Roeck <guenter.roeck@ericsson.com>");
	MODULE_DESCRIPTION("JC42 driver");
	MODULE_LICENSE("GPL");

	module_init(sensors_jc42_init);
	module_exit(sensors_jc42_exit);