drivers/hwmon/lm95241.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Copyright (C) 2008, 2010 Davide Rizzo <elpa.rizzo@gmail.com>
  *
  * The LM95241 is a sensor chip made by National Semiconductors.
  * It reports up to three temperatures (its own plus up to two external ones).
  * Complete datasheet can be obtained from National's website at:
  *   http://www.national.com/ds.cgi/LM/LM95241.pdf
  */

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

 #define DEVNAME "lm95241"

 static const unsigned short normal_i2c[] = {
 	0x19, 0x2a, 0x2b, I2C_CLIENT_END };

 /* LM95241 registers */
 #define LM95241_REG_R_MAN_ID		0xFE
 #define LM95241_REG_R_CHIP_ID		0xFF
 #define LM95241_REG_R_STATUS		0x02
 #define LM95241_REG_RW_CONFIG		0x03
 #define LM95241_REG_RW_REM_FILTER	0x06
 #define LM95241_REG_RW_TRUTHERM		0x07
 #define LM95241_REG_W_ONE_SHOT		0x0F
 #define LM95241_REG_R_LOCAL_TEMPH	0x10
 #define LM95241_REG_R_REMOTE1_TEMPH	0x11
 #define LM95241_REG_R_REMOTE2_TEMPH	0x12
 #define LM95241_REG_R_LOCAL_TEMPL	0x20
 #define LM95241_REG_R_REMOTE1_TEMPL	0x21
 #define LM95241_REG_R_REMOTE2_TEMPL	0x22
 #define LM95241_REG_RW_REMOTE_MODEL	0x30

 /* LM95241 specific bitfields */
 #define CFG_STOP	BIT(6)
 #define CFG_CR0076	0x00
 #define CFG_CR0182	BIT(4)
 #define CFG_CR1000	BIT(5)
 #define CFG_CR2700	(BIT(4) | BIT(5))
 #define CFG_CRMASK	(BIT(4) | BIT(5))
 #define R1MS_MASK	BIT(0)
 #define R2MS_MASK	BIT(2)
 #define R1DF_MASK	BIT(1)
 #define R2DF_MASK	BIT(2)
 #define R1FE_MASK	BIT(0)
 #define R2FE_MASK	BIT(2)
 #define R1DM		BIT(0)
 #define R2DM		BIT(1)
 #define TT1_SHIFT	0
 #define TT2_SHIFT	4
 #define TT_OFF		0
 #define TT_ON		1
 #define TT_MASK		7
 #define NATSEMI_MAN_ID	0x01
 #define LM95231_CHIP_ID	0xA1
 #define LM95241_CHIP_ID	0xA4

 static const u8 lm95241_reg_address[] = {
 	LM95241_REG_R_LOCAL_TEMPH,
 	LM95241_REG_R_LOCAL_TEMPL,
 	LM95241_REG_R_REMOTE1_TEMPH,
 	LM95241_REG_R_REMOTE1_TEMPL,
 	LM95241_REG_R_REMOTE2_TEMPH,
 	LM95241_REG_R_REMOTE2_TEMPL
 };

 /* Client data (each client gets its own) */
 struct lm95241_data {
 	struct i2c_client *client;
 	struct mutex update_lock;
 	unsigned long last_updated;	/* in jiffies */
 	unsigned long interval;		/* in milli-seconds */
 	bool valid;		/* false until following fields are valid */
 	/* registers values */
 	u8 temp[ARRAY_SIZE(lm95241_reg_address)];
 	u8 status, config, model, trutherm;
 };

 /* Conversions */
 static int temp_from_reg_signed(u8 val_h, u8 val_l)
 {
 	s16 val_hl = (val_h << 8) | val_l;
 	return val_hl * 1000 / 256;
 }

 static int temp_from_reg_unsigned(u8 val_h, u8 val_l)
 {
 	u16 val_hl = (val_h << 8) | val_l;
 	return val_hl * 1000 / 256;
 }

 static struct lm95241_data *lm95241_update_device(struct device *dev)
 {
 	struct lm95241_data *data = dev_get_drvdata(dev);
 	struct i2c_client *client = data->client;

 	mutex_lock(&data->update_lock);

 	if (time_after(jiffies, data->last_updated
 		       + msecs_to_jiffies(data->interval)) ||
 	    !data->valid) {
 		int i;

 		dev_dbg(dev, "Updating lm95241 data.\n");
 		for (i = 0; i < ARRAY_SIZE(lm95241_reg_address); i++)
 			data->temp[i]
 			  = i2c_smbus_read_byte_data(client,
 						     lm95241_reg_address[i]);

 		data->status = i2c_smbus_read_byte_data(client,
 							LM95241_REG_R_STATUS);
 		data->last_updated = jiffies;
 		data->valid = true;
 	}

 	mutex_unlock(&data->update_lock);

 	return data;
 }

 static int lm95241_read_chip(struct device *dev, u32 attr, int channel,
 			     long *val)
 {
 	struct lm95241_data *data = dev_get_drvdata(dev);

 	switch (attr) {
 	case hwmon_chip_update_interval:
 		*val = data->interval;
 		return 0;
 	default:
 		return -EOPNOTSUPP;
 	}
 }

 static int lm95241_read_temp(struct device *dev, u32 attr, int channel,
 			     long *val)
 {
 	struct lm95241_data *data = lm95241_update_device(dev);

 	switch (attr) {
 	case hwmon_temp_input:
 		if (!channel || (data->config & BIT(channel - 1)))
 			*val = temp_from_reg_signed(data->temp[channel * 2],
 						data->temp[channel * 2 + 1]);
 		else
 			*val = temp_from_reg_unsigned(data->temp[channel * 2],
 						data->temp[channel * 2 + 1]);
 		return 0;
 	case hwmon_temp_min:
 		if (channel == 1)
 			*val = (data->config & R1DF_MASK) ? -128000 : 0;
 		else
 			*val = (data->config & R2DF_MASK) ? -128000 : 0;
 		return 0;
 	case hwmon_temp_max:
 		if (channel == 1)
 			*val = (data->config & R1DF_MASK) ? 127875 : 255875;
 		else
 			*val = (data->config & R2DF_MASK) ? 127875 : 255875;
 		return 0;
 	case hwmon_temp_type:
 		if (channel == 1)
 			*val = (data->model & R1MS_MASK) ? 1 : 2;
 		else
 			*val = (data->model & R2MS_MASK) ? 1 : 2;
 		return 0;
 	case hwmon_temp_fault:
 		if (channel == 1)
 			*val = !!(data->status & R1DM);
 		else
 			*val = !!(data->status & R2DM);
 		return 0;
 	default:
 		return -EOPNOTSUPP;
 	}
 }

 static int lm95241_read(struct device *dev, enum hwmon_sensor_types type,
 			u32 attr, int channel, long *val)
 {
 	switch (type) {
 	case hwmon_chip:
 		return lm95241_read_chip(dev, attr, channel, val);
 	case hwmon_temp:
 		return lm95241_read_temp(dev, attr, channel, val);
 	default:
 		return -EOPNOTSUPP;
 	}
 }

 static int lm95241_write_chip(struct device *dev, u32 attr, int channel,
 			      long val)
 {
 	struct lm95241_data *data = dev_get_drvdata(dev);
 	int convrate;
 	u8 config;
 	int ret;

 	mutex_lock(&data->update_lock);

 	switch (attr) {
 	case hwmon_chip_update_interval:
 		config = data->config & ~CFG_CRMASK;
 		if (val < 130) {
 			convrate = 76;
 			config |= CFG_CR0076;
 		} else if (val < 590) {
 			convrate = 182;
 			config |= CFG_CR0182;
 		} else if (val < 1850) {
 			convrate = 1000;
 			config |= CFG_CR1000;
 		} else {
 			convrate = 2700;
 			config |= CFG_CR2700;
 		}
 		data->interval = convrate;
 		data->config = config;
 		ret = i2c_smbus_write_byte_data(data->client,
 						LM95241_REG_RW_CONFIG, config);
 		break;
 	default:
 		ret = -EOPNOTSUPP;
 		break;
 	}
 	mutex_unlock(&data->update_lock);
 	return ret;
 }

 static int lm95241_write_temp(struct device *dev, u32 attr, int channel,
 			      long val)
 {
 	struct lm95241_data *data = dev_get_drvdata(dev);
 	struct i2c_client *client = data->client;
 	int ret;

 	mutex_lock(&data->update_lock);

 	switch (attr) {
 	case hwmon_temp_min:
 		if (channel == 1) {
 			if (val < 0)
 				data->config |= R1DF_MASK;
 			else
 				data->config &= ~R1DF_MASK;
 		} else {
 			if (val < 0)
 				data->config |= R2DF_MASK;
 			else
 				data->config &= ~R2DF_MASK;
 		}
 		data->valid = false;
 		ret = i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG,
 						data->config);
 		break;
 	case hwmon_temp_max:
 		if (channel == 1) {
 			if (val <= 127875)
 				data->config |= R1DF_MASK;
 			else
 				data->config &= ~R1DF_MASK;
 		} else {
 			if (val <= 127875)
 				data->config |= R2DF_MASK;
 			else
 				data->config &= ~R2DF_MASK;
 		}
 		data->valid = false;
 		ret = i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG,
 						data->config);
 		break;
 	case hwmon_temp_type:
 		if (val != 1 && val != 2) {
 			ret = -EINVAL;
 			break;
 		}
 		if (channel == 1) {
 			data->trutherm &= ~(TT_MASK << TT1_SHIFT);
 			if (val == 1) {
 				data->model |= R1MS_MASK;
 				data->trutherm |= (TT_ON << TT1_SHIFT);
 			} else {
 				data->model &= ~R1MS_MASK;
 				data->trutherm |= (TT_OFF << TT1_SHIFT);
 			}
 		} else {
 			data->trutherm &= ~(TT_MASK << TT2_SHIFT);
 			if (val == 1) {
 				data->model |= R2MS_MASK;
 				data->trutherm |= (TT_ON << TT2_SHIFT);
 			} else {
 				data->model &= ~R2MS_MASK;
 				data->trutherm |= (TT_OFF << TT2_SHIFT);
 			}
 		}
 		ret = i2c_smbus_write_byte_data(client,
 						LM95241_REG_RW_REMOTE_MODEL,
 						data->model);
 		if (ret < 0)
 			break;
 		ret = i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM,
 						data->trutherm);
 		break;
 	default:
 		ret = -EOPNOTSUPP;
 		break;
 	}

 	mutex_unlock(&data->update_lock);

 	return ret;
 }

 static int lm95241_write(struct device *dev, enum hwmon_sensor_types type,
 			 u32 attr, int channel, long val)
 {
 	switch (type) {
 	case hwmon_chip:
 		return lm95241_write_chip(dev, attr, channel, val);
 	case hwmon_temp:
 		return lm95241_write_temp(dev, attr, channel, val);
 	default:
 		return -EOPNOTSUPP;
 	}
 }

 static umode_t lm95241_is_visible(const void *data,
 				  enum hwmon_sensor_types type,
 				  u32 attr, int channel)
 {
 	switch (type) {
 	case hwmon_chip:
 		switch (attr) {
 		case hwmon_chip_update_interval:
 			return 0644;
 		}
 		break;
 	case hwmon_temp:
 		switch (attr) {
 		case hwmon_temp_input:
 			return 0444;
 		case hwmon_temp_fault:
 			return 0444;
 		case hwmon_temp_min:
 		case hwmon_temp_max:
 		case hwmon_temp_type:
 			return 0644;
 		}
 		break;
 	default:
 		break;
 	}
 	return 0;
 }

 /* Return 0 if detection is successful, -ENODEV otherwise */
 static int lm95241_detect(struct i2c_client *new_client,
 			  struct i2c_board_info *info)
 {
 	struct i2c_adapter *adapter = new_client->adapter;
 	const char *name;
 	int mfg_id, chip_id;

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

 	mfg_id = i2c_smbus_read_byte_data(new_client, LM95241_REG_R_MAN_ID);
 	if (mfg_id != NATSEMI_MAN_ID)
 		return -ENODEV;

 	chip_id = i2c_smbus_read_byte_data(new_client, LM95241_REG_R_CHIP_ID);
 	switch (chip_id) {
 	case LM95231_CHIP_ID:
 		name = "lm95231";
 		break;
 	case LM95241_CHIP_ID:
 		name = "lm95241";
 		break;
 	default:
 		return -ENODEV;
 	}

 	/* Fill the i2c board info */
 	strscpy(info->type, name, I2C_NAME_SIZE);
 	return 0;
 }

 static void lm95241_init_client(struct i2c_client *client,
 				struct lm95241_data *data)
 {
 	data->interval = 1000;
 	data->config = CFG_CR1000;
 	data->trutherm = (TT_OFF << TT1_SHIFT) | (TT_OFF << TT2_SHIFT);

 	i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, data->config);
 	i2c_smbus_write_byte_data(client, LM95241_REG_RW_REM_FILTER,
 				  R1FE_MASK | R2FE_MASK);
 	i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM,
 				  data->trutherm);
 	i2c_smbus_write_byte_data(client, LM95241_REG_RW_REMOTE_MODEL,
 				  data->model);
 }

 static const struct hwmon_channel_info * const lm95241_info[] = {
 	HWMON_CHANNEL_INFO(chip,
 			   HWMON_C_UPDATE_INTERVAL),
 	HWMON_CHANNEL_INFO(temp,
 			   HWMON_T_INPUT,
 			   HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN |
 			   HWMON_T_TYPE | HWMON_T_FAULT,
 			   HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN |
 			   HWMON_T_TYPE | HWMON_T_FAULT),
 	NULL
 };

 static const struct hwmon_ops lm95241_hwmon_ops = {
 	.is_visible = lm95241_is_visible,
 	.read = lm95241_read,
 	.write = lm95241_write,
 };

 static const struct hwmon_chip_info lm95241_chip_info = {
 	.ops = &lm95241_hwmon_ops,
 	.info = lm95241_info,
 };

 static int lm95241_probe(struct i2c_client *client)
 {
 	struct device *dev = &client->dev;
 	struct lm95241_data *data;
 	struct device *hwmon_dev;

 	data = devm_kzalloc(dev, sizeof(struct lm95241_data), GFP_KERNEL);
 	if (!data)
 		return -ENOMEM;

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

 	/* Initialize the LM95241 chip */
 	lm95241_init_client(client, data);

 	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
 							   data,
 							   &lm95241_chip_info,
 							   NULL);
 	return PTR_ERR_OR_ZERO(hwmon_dev);
 }

 /* Driver data (common to all clients) */
 static const struct i2c_device_id lm95241_id[] = {
 	{ "lm95231", 0 },
 	{ "lm95241", 0 },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, lm95241_id);

 static struct i2c_driver lm95241_driver = {
 	.class		= I2C_CLASS_HWMON,
 	.driver = {
 		.name	= DEVNAME,
 	},
 	.probe		= lm95241_probe,
 	.id_table	= lm95241_id,
 	.detect		= lm95241_detect,
 	.address_list	= normal_i2c,
 };

 module_i2c_driver(lm95241_driver);

 MODULE_AUTHOR("Davide Rizzo <elpa.rizzo@gmail.com>");
 MODULE_DESCRIPTION("LM95231/LM95241 sensor driver");
 MODULE_LICENSE("GPL");
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* Copyright (C) 2008, 2010 Davide Rizzo <elpa.rizzo@gmail.com>
	*
	* The LM95241 is a sensor chip made by National Semiconductors.
	* It reports up to three temperatures (its own plus up to two external ones).
	* Complete datasheet can be obtained from National's website at:
	* http://www.national.com/ds.cgi/LM/LM95241.pdf
	*/

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

	#define DEVNAME "lm95241"

	static const unsigned short normal_i2c[] = {
	0x19, 0x2a, 0x2b, I2C_CLIENT_END };

	/* LM95241 registers */
	#define LM95241_REG_R_MAN_ID 0xFE
	#define LM95241_REG_R_CHIP_ID 0xFF
	#define LM95241_REG_R_STATUS 0x02
	#define LM95241_REG_RW_CONFIG 0x03
	#define LM95241_REG_RW_REM_FILTER 0x06
	#define LM95241_REG_RW_TRUTHERM 0x07
	#define LM95241_REG_W_ONE_SHOT 0x0F
	#define LM95241_REG_R_LOCAL_TEMPH 0x10
	#define LM95241_REG_R_REMOTE1_TEMPH 0x11
	#define LM95241_REG_R_REMOTE2_TEMPH 0x12
	#define LM95241_REG_R_LOCAL_TEMPL 0x20
	#define LM95241_REG_R_REMOTE1_TEMPL 0x21
	#define LM95241_REG_R_REMOTE2_TEMPL 0x22
	#define LM95241_REG_RW_REMOTE_MODEL 0x30

	/* LM95241 specific bitfields */
	#define CFG_STOP BIT(6)
	#define CFG_CR0076 0x00
	#define CFG_CR0182 BIT(4)
	#define CFG_CR1000 BIT(5)
	#define CFG_CR2700 (BIT(4) \| BIT(5))
	#define CFG_CRMASK (BIT(4) \| BIT(5))
	#define R1MS_MASK BIT(0)
	#define R2MS_MASK BIT(2)
	#define R1DF_MASK BIT(1)
	#define R2DF_MASK BIT(2)
	#define R1FE_MASK BIT(0)
	#define R2FE_MASK BIT(2)
	#define R1DM BIT(0)
	#define R2DM BIT(1)
	#define TT1_SHIFT 0
	#define TT2_SHIFT 4
	#define TT_OFF 0
	#define TT_ON 1
	#define TT_MASK 7
	#define NATSEMI_MAN_ID 0x01
	#define LM95231_CHIP_ID 0xA1
	#define LM95241_CHIP_ID 0xA4

	static const u8 lm95241_reg_address[] = {
	LM95241_REG_R_LOCAL_TEMPH,
	LM95241_REG_R_LOCAL_TEMPL,
	LM95241_REG_R_REMOTE1_TEMPH,
	LM95241_REG_R_REMOTE1_TEMPL,
	LM95241_REG_R_REMOTE2_TEMPH,
	LM95241_REG_R_REMOTE2_TEMPL
	};

	/* Client data (each client gets its own) */
	struct lm95241_data {
	struct i2c_client *client;
	struct mutex update_lock;
	unsigned long last_updated; /* in jiffies */
	unsigned long interval; /* in milli-seconds */
	bool valid; /* false until following fields are valid */
	/* registers values */
	u8 temp[ARRAY_SIZE(lm95241_reg_address)];
	u8 status, config, model, trutherm;
	};

	/* Conversions */
	static int temp_from_reg_signed(u8 val_h, u8 val_l)
	{
	s16 val_hl = (val_h << 8) \| val_l;
	return val_hl * 1000 / 256;
	}

	static int temp_from_reg_unsigned(u8 val_h, u8 val_l)
	{
	u16 val_hl = (val_h << 8) \| val_l;
	return val_hl * 1000 / 256;
	}

	static struct lm95241_data lm95241_update_device(struct device dev)
	{
	struct lm95241_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;

	mutex_lock(&data->update_lock);

	if (time_after(jiffies, data->last_updated
	+ msecs_to_jiffies(data->interval)) \|\|
	!data->valid) {
	int i;

	dev_dbg(dev, "Updating lm95241 data.\n");
	for (i = 0; i < ARRAY_SIZE(lm95241_reg_address); i++)
	data->temp[i]
	= i2c_smbus_read_byte_data(client,
	lm95241_reg_address[i]);

	data->status = i2c_smbus_read_byte_data(client,
	LM95241_REG_R_STATUS);
	data->last_updated = jiffies;
	data->valid = true;
	}

	mutex_unlock(&data->update_lock);

	return data;
	}

	static int lm95241_read_chip(struct device *dev, u32 attr, int channel,
	long *val)
	{
	struct lm95241_data *data = dev_get_drvdata(dev);

	switch (attr) {
	case hwmon_chip_update_interval:
	*val = data->interval;
	return 0;
	default:
	return -EOPNOTSUPP;
	}
	}

	static int lm95241_read_temp(struct device *dev, u32 attr, int channel,
	long *val)
	{
	struct lm95241_data *data = lm95241_update_device(dev);

	switch (attr) {
	case hwmon_temp_input:
	if (!channel \|\| (data->config & BIT(channel - 1)))
	val = temp_from_reg_signed(data->temp[channel 2],
	data->temp[channel * 2 + 1]);
	else
	val = temp_from_reg_unsigned(data->temp[channel 2],
	data->temp[channel * 2 + 1]);
	return 0;
	case hwmon_temp_min:
	if (channel == 1)
	*val = (data->config & R1DF_MASK) ? -128000 : 0;
	else
	*val = (data->config & R2DF_MASK) ? -128000 : 0;
	return 0;
	case hwmon_temp_max:
	if (channel == 1)
	*val = (data->config & R1DF_MASK) ? 127875 : 255875;
	else
	*val = (data->config & R2DF_MASK) ? 127875 : 255875;
	return 0;
	case hwmon_temp_type:
	if (channel == 1)
	*val = (data->model & R1MS_MASK) ? 1 : 2;
	else
	*val = (data->model & R2MS_MASK) ? 1 : 2;
	return 0;
	case hwmon_temp_fault:
	if (channel == 1)
	*val = !!(data->status & R1DM);
	else
	*val = !!(data->status & R2DM);
	return 0;
	default:
	return -EOPNOTSUPP;
	}
	}

	static int lm95241_read(struct device *dev, enum hwmon_sensor_types type,
	u32 attr, int channel, long *val)
	{
	switch (type) {
	case hwmon_chip:
	return lm95241_read_chip(dev, attr, channel, val);
	case hwmon_temp:
	return lm95241_read_temp(dev, attr, channel, val);
	default:
	return -EOPNOTSUPP;
	}
	}

	static int lm95241_write_chip(struct device *dev, u32 attr, int channel,
	long val)
	{
	struct lm95241_data *data = dev_get_drvdata(dev);
	int convrate;
	u8 config;
	int ret;

	mutex_lock(&data->update_lock);

	switch (attr) {
	case hwmon_chip_update_interval:
	config = data->config & ~CFG_CRMASK;
	if (val < 130) {
	convrate = 76;
	config \|= CFG_CR0076;
	} else if (val < 590) {
	convrate = 182;
	config \|= CFG_CR0182;
	} else if (val < 1850) {
	convrate = 1000;
	config \|= CFG_CR1000;
	} else {
	convrate = 2700;
	config \|= CFG_CR2700;
	}
	data->interval = convrate;
	data->config = config;
	ret = i2c_smbus_write_byte_data(data->client,
	LM95241_REG_RW_CONFIG, config);
	break;
	default:
	ret = -EOPNOTSUPP;
	break;
	}
	mutex_unlock(&data->update_lock);
	return ret;
	}

	static int lm95241_write_temp(struct device *dev, u32 attr, int channel,
	long val)
	{
	struct lm95241_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;
	int ret;

	mutex_lock(&data->update_lock);

	switch (attr) {
	case hwmon_temp_min:
	if (channel == 1) {
	if (val < 0)
	data->config \|= R1DF_MASK;
	else
	data->config &= ~R1DF_MASK;
	} else {
	if (val < 0)
	data->config \|= R2DF_MASK;
	else
	data->config &= ~R2DF_MASK;
	}
	data->valid = false;
	ret = i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG,
	data->config);
	break;
	case hwmon_temp_max:
	if (channel == 1) {
	if (val <= 127875)
	data->config \|= R1DF_MASK;
	else
	data->config &= ~R1DF_MASK;
	} else {
	if (val <= 127875)
	data->config \|= R2DF_MASK;
	else
	data->config &= ~R2DF_MASK;
	}
	data->valid = false;
	ret = i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG,
	data->config);
	break;
	case hwmon_temp_type:
	if (val != 1 && val != 2) {
	ret = -EINVAL;
	break;
	}
	if (channel == 1) {
	data->trutherm &= ~(TT_MASK << TT1_SHIFT);
	if (val == 1) {
	data->model \|= R1MS_MASK;
	data->trutherm \|= (TT_ON << TT1_SHIFT);
	} else {
	data->model &= ~R1MS_MASK;
	data->trutherm \|= (TT_OFF << TT1_SHIFT);
	}
	} else {
	data->trutherm &= ~(TT_MASK << TT2_SHIFT);
	if (val == 1) {
	data->model \|= R2MS_MASK;
	data->trutherm \|= (TT_ON << TT2_SHIFT);
	} else {
	data->model &= ~R2MS_MASK;
	data->trutherm \|= (TT_OFF << TT2_SHIFT);
	}
	}
	ret = i2c_smbus_write_byte_data(client,
	LM95241_REG_RW_REMOTE_MODEL,
	data->model);
	if (ret < 0)
	break;
	ret = i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM,
	data->trutherm);
	break;
	default:
	ret = -EOPNOTSUPP;
	break;
	}

	mutex_unlock(&data->update_lock);

	return ret;
	}

	static int lm95241_write(struct device *dev, enum hwmon_sensor_types type,
	u32 attr, int channel, long val)
	{
	switch (type) {
	case hwmon_chip:
	return lm95241_write_chip(dev, attr, channel, val);
	case hwmon_temp:
	return lm95241_write_temp(dev, attr, channel, val);
	default:
	return -EOPNOTSUPP;
	}
	}

	static umode_t lm95241_is_visible(const void *data,
	enum hwmon_sensor_types type,
	u32 attr, int channel)
	{
	switch (type) {
	case hwmon_chip:
	switch (attr) {
	case hwmon_chip_update_interval:
	return 0644;
	}
	break;
	case hwmon_temp:
	switch (attr) {
	case hwmon_temp_input:
	return 0444;
	case hwmon_temp_fault:
	return 0444;
	case hwmon_temp_min:
	case hwmon_temp_max:
	case hwmon_temp_type:
	return 0644;
	}
	break;
	default:
	break;
	}
	return 0;
	}

	/* Return 0 if detection is successful, -ENODEV otherwise */
	static int lm95241_detect(struct i2c_client *new_client,
	struct i2c_board_info *info)
	{
	struct i2c_adapter *adapter = new_client->adapter;
	const char *name;
	int mfg_id, chip_id;

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

	mfg_id = i2c_smbus_read_byte_data(new_client, LM95241_REG_R_MAN_ID);
	if (mfg_id != NATSEMI_MAN_ID)
	return -ENODEV;

	chip_id = i2c_smbus_read_byte_data(new_client, LM95241_REG_R_CHIP_ID);
	switch (chip_id) {
	case LM95231_CHIP_ID:
	name = "lm95231";
	break;
	case LM95241_CHIP_ID:
	name = "lm95241";
	break;
	default:
	return -ENODEV;
	}

	/* Fill the i2c board info */
	strscpy(info->type, name, I2C_NAME_SIZE);
	return 0;
	}

	static void lm95241_init_client(struct i2c_client *client,
	struct lm95241_data *data)
	{
	data->interval = 1000;
	data->config = CFG_CR1000;
	data->trutherm = (TT_OFF << TT1_SHIFT) \| (TT_OFF << TT2_SHIFT);

	i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, data->config);
	i2c_smbus_write_byte_data(client, LM95241_REG_RW_REM_FILTER,
	R1FE_MASK \| R2FE_MASK);
	i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM,
	data->trutherm);
	i2c_smbus_write_byte_data(client, LM95241_REG_RW_REMOTE_MODEL,
	data->model);
	}

	static const struct hwmon_channel_info * const lm95241_info[] = {
	HWMON_CHANNEL_INFO(chip,
	HWMON_C_UPDATE_INTERVAL),
	HWMON_CHANNEL_INFO(temp,
	HWMON_T_INPUT,
	HWMON_T_INPUT \| HWMON_T_MAX \| HWMON_T_MIN \|
	HWMON_T_TYPE \| HWMON_T_FAULT,
	HWMON_T_INPUT \| HWMON_T_MAX \| HWMON_T_MIN \|
	HWMON_T_TYPE \| HWMON_T_FAULT),
	NULL
	};

	static const struct hwmon_ops lm95241_hwmon_ops = {
	.is_visible = lm95241_is_visible,
	.read = lm95241_read,
	.write = lm95241_write,
	};

	static const struct hwmon_chip_info lm95241_chip_info = {
	.ops = &lm95241_hwmon_ops,
	.info = lm95241_info,
	};

	static int lm95241_probe(struct i2c_client *client)
	{
	struct device *dev = &client->dev;
	struct lm95241_data *data;
	struct device *hwmon_dev;

	data = devm_kzalloc(dev, sizeof(struct lm95241_data), GFP_KERNEL);
	if (!data)
	return -ENOMEM;

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

	/* Initialize the LM95241 chip */
	lm95241_init_client(client, data);

	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
	data,
	&lm95241_chip_info,
	NULL);
	return PTR_ERR_OR_ZERO(hwmon_dev);
	}

	/* Driver data (common to all clients) */
	static const struct i2c_device_id lm95241_id[] = {
	{ "lm95231", 0 },
	{ "lm95241", 0 },
	{ }
	};
	MODULE_DEVICE_TABLE(i2c, lm95241_id);

	static struct i2c_driver lm95241_driver = {
	.class = I2C_CLASS_HWMON,
	.driver = {
	.name = DEVNAME,
	},
	.probe = lm95241_probe,
	.id_table = lm95241_id,
	.detect = lm95241_detect,
	.address_list = normal_i2c,
	};

	module_i2c_driver(lm95241_driver);

	MODULE_AUTHOR("Davide Rizzo <elpa.rizzo@gmail.com>");
	MODULE_DESCRIPTION("LM95231/LM95241 sensor driver");
	MODULE_LICENSE("GPL");