drivers/hwmon/w83l785ts.c - linux - Git at Google

 /*
  * w83l785ts.c - Part of lm_sensors, Linux kernel modules for hardware
  *               monitoring
  * Copyright (C) 2003-2009  Jean Delvare <khali@linux-fr.org>
  *
  * Inspired from the lm83 driver. The W83L785TS-S is a sensor chip made
  * by Winbond. It reports a single external temperature with a 1 deg
  * resolution and a 3 deg accuracy. Datasheet can be obtained from
  * Winbond's website at:
  *   http://www.winbond-usa.com/products/winbond_products/pdfs/PCIC/W83L785TS-S.pdf
  *
  * Ported to Linux 2.6 by Wolfgang Ziegler <nuppla@gmx.at> and Jean Delvare
  * <khali@linux-fr.org>.
  *
  * Thanks to James Bolt <james@evilpenguin.com> for benchmarking the read
  * error handling mechanism.
  *
  * 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/delay.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>

 /* How many retries on register read error */
 #define MAX_RETRIES	5

 /*
  * Address to scan
  * Address is fully defined internally and cannot be changed.
  */

 static const unsigned short normal_i2c[] = { 0x2e, I2C_CLIENT_END };

 /*
  * The W83L785TS-S registers
  * Manufacturer ID is 0x5CA3 for Winbond.
  */

 #define W83L785TS_REG_MAN_ID1		0x4D
 #define W83L785TS_REG_MAN_ID2		0x4C
 #define W83L785TS_REG_CHIP_ID		0x4E
 #define W83L785TS_REG_CONFIG		0x40
 #define W83L785TS_REG_TYPE		0x52
 #define W83L785TS_REG_TEMP		0x27
 #define W83L785TS_REG_TEMP_OVER		0x53 /* not sure about this one */

 /*
  * Conversions
  * The W83L785TS-S uses signed 8-bit values.
  */

 #define TEMP_FROM_REG(val)	((val) * 1000)

 /*
  * Functions declaration
  */

 static int w83l785ts_probe(struct i2c_client *client,
 			   const struct i2c_device_id *id);
 static int w83l785ts_detect(struct i2c_client *client,
 			    struct i2c_board_info *info);
 static int w83l785ts_remove(struct i2c_client *client);
 static u8 w83l785ts_read_value(struct i2c_client *client, u8 reg, u8 defval);
 static struct w83l785ts_data *w83l785ts_update_device(struct device *dev);

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

 static const struct i2c_device_id w83l785ts_id[] = {
 	{ "w83l785ts", 0 },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, w83l785ts_id);

 static struct i2c_driver w83l785ts_driver = {
 	.class		= I2C_CLASS_HWMON,
 	.driver = {
 		.name	= "w83l785ts",
 	},
 	.probe		= w83l785ts_probe,
 	.remove		= w83l785ts_remove,
 	.id_table	= w83l785ts_id,
 	.detect		= w83l785ts_detect,
 	.address_list	= normal_i2c,
 };

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

 struct w83l785ts_data {
 	struct device *hwmon_dev;
 	struct mutex update_lock;
 	char valid; /* zero until following fields are valid */
 	unsigned long last_updated; /* in jiffies */

 	/* registers values */
 	s8 temp[2]; /* 0: input
 		       1: critical limit */
 };

 /*
  * Sysfs stuff
  */

 static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
 	char *buf)
 {
 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 	struct w83l785ts_data *data = w83l785ts_update_device(dev);
 	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[attr->index]));
 }

 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
 static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO, show_temp, NULL, 1);

 /*
  * Real code
  */

 /* Return 0 if detection is successful, -ENODEV otherwise */
 static int w83l785ts_detect(struct i2c_client *client,
 			    struct i2c_board_info *info)
 {
 	struct i2c_adapter *adapter = client->adapter;
 	u16 man_id;
 	u8 chip_id;

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

 	/* detection */
 	if ((w83l785ts_read_value(client, W83L785TS_REG_CONFIG, 0) & 0x80)
 	 || (w83l785ts_read_value(client, W83L785TS_REG_TYPE, 0) & 0xFC)) {
 		dev_dbg(&adapter->dev,
 			"W83L785TS-S detection failed at 0x%02x\n",
 			client->addr);
 		return -ENODEV;
 	}

 	/* Identification */
 	man_id = (w83l785ts_read_value(client, W83L785TS_REG_MAN_ID1, 0) << 8)
 	       + w83l785ts_read_value(client, W83L785TS_REG_MAN_ID2, 0);
 	chip_id = w83l785ts_read_value(client, W83L785TS_REG_CHIP_ID, 0);

 	if (man_id != 0x5CA3		/* Winbond */
 	 || chip_id != 0x70) {		/* W83L785TS-S */
 		dev_dbg(&adapter->dev,
 			"Unsupported chip (man_id=0x%04X, chip_id=0x%02X)\n",
 			man_id, chip_id);
 		return -ENODEV;
 	}

 	strlcpy(info->type, "w83l785ts", I2C_NAME_SIZE);

 	return 0;
 }

 static int w83l785ts_probe(struct i2c_client *new_client,
 			   const struct i2c_device_id *id)
 {
 	struct w83l785ts_data *data;
 	int err = 0;

 	data = kzalloc(sizeof(struct w83l785ts_data), GFP_KERNEL);
 	if (!data) {
 		err = -ENOMEM;
 		goto exit;
 	}

 	i2c_set_clientdata(new_client, data);
 	data->valid = 0;
 	mutex_init(&data->update_lock);

 	/* Default values in case the first read fails (unlikely). */
 	data->temp[1] = data->temp[0] = 0;

 	/*
 	 * Initialize the W83L785TS chip
 	 * Nothing yet, assume it is already started.
 	 */

 	err = device_create_file(&new_client->dev,
 				 &sensor_dev_attr_temp1_input.dev_attr);
 	if (err)
 		goto exit_remove;

 	err = device_create_file(&new_client->dev,
 				 &sensor_dev_attr_temp1_max.dev_attr);
 	if (err)
 		goto exit_remove;

 	/* Register sysfs hooks */
 	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:
 	device_remove_file(&new_client->dev,
 			   &sensor_dev_attr_temp1_input.dev_attr);
 	device_remove_file(&new_client->dev,
 			   &sensor_dev_attr_temp1_max.dev_attr);
 	kfree(data);
 exit:
 	return err;
 }

 static int w83l785ts_remove(struct i2c_client *client)
 {
 	struct w83l785ts_data *data = i2c_get_clientdata(client);

 	hwmon_device_unregister(data->hwmon_dev);
 	device_remove_file(&client->dev,
 			   &sensor_dev_attr_temp1_input.dev_attr);
 	device_remove_file(&client->dev,
 			   &sensor_dev_attr_temp1_max.dev_attr);

 	kfree(data);
 	return 0;
 }

 static u8 w83l785ts_read_value(struct i2c_client *client, u8 reg, u8 defval)
 {
 	int value, i;
 	struct device *dev;
 	const char *prefix;

 	/* We might be called during detection, at which point the client
 	   isn't yet fully initialized, so we can't use dev_dbg on it */
 	if (i2c_get_clientdata(client)) {
 		dev = &client->dev;
 		prefix = "";
 	} else {
 		dev = &client->adapter->dev;
 		prefix = "w83l785ts: ";
 	}

 	/* Frequent read errors have been reported on Asus boards, so we
 	 * retry on read errors. If it still fails (unlikely), return the
 	 * default value requested by the caller. */
 	for (i = 1; i <= MAX_RETRIES; i++) {
 		value = i2c_smbus_read_byte_data(client, reg);
 		if (value >= 0) {
 			dev_dbg(dev, "%sRead 0x%02x from register 0x%02x.\n",
 				prefix, value, reg);
 			return value;
 		}
 		dev_dbg(dev, "%sRead failed, will retry in %d.\n", prefix, i);
 		msleep(i);
 	}

 	dev_err(dev, "%sCouldn't read value from register 0x%02x.\n", prefix,
 		reg);
 	return defval;
 }

 static struct w83l785ts_data *w83l785ts_update_device(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct w83l785ts_data *data = i2c_get_clientdata(client);

 	mutex_lock(&data->update_lock);

 	if (!data->valid || time_after(jiffies, data->last_updated + HZ * 2)) {
 		dev_dbg(&client->dev, "Updating w83l785ts data.\n");
 		data->temp[0] = w83l785ts_read_value(client,
 				W83L785TS_REG_TEMP, data->temp[0]);
 		data->temp[1] = w83l785ts_read_value(client,
 				W83L785TS_REG_TEMP_OVER, data->temp[1]);

 		data->last_updated = jiffies;
 		data->valid = 1;
 	}

 	mutex_unlock(&data->update_lock);

 	return data;
 }

 module_i2c_driver(w83l785ts_driver);

 MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
 MODULE_DESCRIPTION("W83L785TS-S driver");
 MODULE_LICENSE("GPL");
	/*
	* w83l785ts.c - Part of lm_sensors, Linux kernel modules for hardware
	* monitoring
	* Copyright (C) 2003-2009 Jean Delvare <khali@linux-fr.org>
	*
	* Inspired from the lm83 driver. The W83L785TS-S is a sensor chip made
	* by Winbond. It reports a single external temperature with a 1 deg
	* resolution and a 3 deg accuracy. Datasheet can be obtained from
	* Winbond's website at:
	* http://www.winbond-usa.com/products/winbond_products/pdfs/PCIC/W83L785TS-S.pdf
	*
	* Ported to Linux 2.6 by Wolfgang Ziegler <nuppla@gmx.at> and Jean Delvare
	* <khali@linux-fr.org>.
	*
	* Thanks to James Bolt <james@evilpenguin.com> for benchmarking the read
	* error handling mechanism.
	*
	* 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/delay.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>

	/* How many retries on register read error */
	#define MAX_RETRIES 5

	/*
	* Address to scan
	* Address is fully defined internally and cannot be changed.
	*/

	static const unsigned short normal_i2c[] = { 0x2e, I2C_CLIENT_END };

	/*
	* The W83L785TS-S registers
	* Manufacturer ID is 0x5CA3 for Winbond.
	*/

	#define W83L785TS_REG_MAN_ID1 0x4D
	#define W83L785TS_REG_MAN_ID2 0x4C
	#define W83L785TS_REG_CHIP_ID 0x4E
	#define W83L785TS_REG_CONFIG 0x40
	#define W83L785TS_REG_TYPE 0x52
	#define W83L785TS_REG_TEMP 0x27
	#define W83L785TS_REG_TEMP_OVER 0x53 /* not sure about this one */

	/*
	* Conversions
	* The W83L785TS-S uses signed 8-bit values.
	*/

	#define TEMP_FROM_REG(val) ((val) * 1000)

	/*
	* Functions declaration
	*/

	static int w83l785ts_probe(struct i2c_client *client,
	const struct i2c_device_id *id);
	static int w83l785ts_detect(struct i2c_client *client,
	struct i2c_board_info *info);
	static int w83l785ts_remove(struct i2c_client *client);
	static u8 w83l785ts_read_value(struct i2c_client *client, u8 reg, u8 defval);
	static struct w83l785ts_data w83l785ts_update_device(struct device dev);

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

	static const struct i2c_device_id w83l785ts_id[] = {
	{ "w83l785ts", 0 },
	{ }
	};
	MODULE_DEVICE_TABLE(i2c, w83l785ts_id);

	static struct i2c_driver w83l785ts_driver = {
	.class = I2C_CLASS_HWMON,
	.driver = {
	.name = "w83l785ts",
	},
	.probe = w83l785ts_probe,
	.remove = w83l785ts_remove,
	.id_table = w83l785ts_id,
	.detect = w83l785ts_detect,
	.address_list = normal_i2c,
	};

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

	struct w83l785ts_data {
	struct device *hwmon_dev;
	struct mutex update_lock;
	char valid; /* zero until following fields are valid */
	unsigned long last_updated; /* in jiffies */

	/* registers values */
	s8 temp[2]; /* 0: input
	1: critical limit */
	};

	/*
	* Sysfs stuff
	*/

	static ssize_t show_temp(struct device dev, struct device_attribute devattr,
	char *buf)
	{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct w83l785ts_data *data = w83l785ts_update_device(dev);
	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[attr->index]));
	}

	static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
	static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO, show_temp, NULL, 1);

	/*
	* Real code
	*/

	/* Return 0 if detection is successful, -ENODEV otherwise */
	static int w83l785ts_detect(struct i2c_client *client,
	struct i2c_board_info *info)
	{
	struct i2c_adapter *adapter = client->adapter;
	u16 man_id;
	u8 chip_id;

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

	/* detection */
	if ((w83l785ts_read_value(client, W83L785TS_REG_CONFIG, 0) & 0x80)
	\|\| (w83l785ts_read_value(client, W83L785TS_REG_TYPE, 0) & 0xFC)) {
	dev_dbg(&adapter->dev,
	"W83L785TS-S detection failed at 0x%02x\n",
	client->addr);
	return -ENODEV;
	}

	/* Identification */
	man_id = (w83l785ts_read_value(client, W83L785TS_REG_MAN_ID1, 0) << 8)
	+ w83l785ts_read_value(client, W83L785TS_REG_MAN_ID2, 0);
	chip_id = w83l785ts_read_value(client, W83L785TS_REG_CHIP_ID, 0);

	if (man_id != 0x5CA3 /* Winbond */
	\|\| chip_id != 0x70) { /* W83L785TS-S */
	dev_dbg(&adapter->dev,
	"Unsupported chip (man_id=0x%04X, chip_id=0x%02X)\n",
	man_id, chip_id);
	return -ENODEV;
	}

	strlcpy(info->type, "w83l785ts", I2C_NAME_SIZE);

	return 0;
	}

	static int w83l785ts_probe(struct i2c_client *new_client,
	const struct i2c_device_id *id)
	{
	struct w83l785ts_data *data;
	int err = 0;

	data = kzalloc(sizeof(struct w83l785ts_data), GFP_KERNEL);
	if (!data) {
	err = -ENOMEM;
	goto exit;
	}

	i2c_set_clientdata(new_client, data);
	data->valid = 0;
	mutex_init(&data->update_lock);

	/* Default values in case the first read fails (unlikely). */
	data->temp[1] = data->temp[0] = 0;

	/*
	* Initialize the W83L785TS chip
	* Nothing yet, assume it is already started.
	*/

	err = device_create_file(&new_client->dev,
	&sensor_dev_attr_temp1_input.dev_attr);
	if (err)
	goto exit_remove;

	err = device_create_file(&new_client->dev,
	&sensor_dev_attr_temp1_max.dev_attr);
	if (err)
	goto exit_remove;

	/* Register sysfs hooks */
	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:
	device_remove_file(&new_client->dev,
	&sensor_dev_attr_temp1_input.dev_attr);
	device_remove_file(&new_client->dev,
	&sensor_dev_attr_temp1_max.dev_attr);
	kfree(data);
	exit:
	return err;
	}

	static int w83l785ts_remove(struct i2c_client *client)
	{
	struct w83l785ts_data *data = i2c_get_clientdata(client);

	hwmon_device_unregister(data->hwmon_dev);
	device_remove_file(&client->dev,
	&sensor_dev_attr_temp1_input.dev_attr);
	device_remove_file(&client->dev,
	&sensor_dev_attr_temp1_max.dev_attr);

	kfree(data);
	return 0;
	}

	static u8 w83l785ts_read_value(struct i2c_client *client, u8 reg, u8 defval)
	{
	int value, i;
	struct device *dev;
	const char *prefix;

	/* We might be called during detection, at which point the client
	isn't yet fully initialized, so we can't use dev_dbg on it */
	if (i2c_get_clientdata(client)) {
	dev = &client->dev;
	prefix = "";
	} else {
	dev = &client->adapter->dev;
	prefix = "w83l785ts: ";
	}

	/* Frequent read errors have been reported on Asus boards, so we
	* retry on read errors. If it still fails (unlikely), return the
	* default value requested by the caller. */
	for (i = 1; i <= MAX_RETRIES; i++) {
	value = i2c_smbus_read_byte_data(client, reg);
	if (value >= 0) {
	dev_dbg(dev, "%sRead 0x%02x from register 0x%02x.\n",
	prefix, value, reg);
	return value;
	}
	dev_dbg(dev, "%sRead failed, will retry in %d.\n", prefix, i);
	msleep(i);
	}

	dev_err(dev, "%sCouldn't read value from register 0x%02x.\n", prefix,
	reg);
	return defval;
	}

	static struct w83l785ts_data w83l785ts_update_device(struct device dev)
	{
	struct i2c_client *client = to_i2c_client(dev);
	struct w83l785ts_data *data = i2c_get_clientdata(client);

	mutex_lock(&data->update_lock);

	if (!data->valid \|\| time_after(jiffies, data->last_updated + HZ * 2)) {
	dev_dbg(&client->dev, "Updating w83l785ts data.\n");
	data->temp[0] = w83l785ts_read_value(client,
	W83L785TS_REG_TEMP, data->temp[0]);
	data->temp[1] = w83l785ts_read_value(client,
	W83L785TS_REG_TEMP_OVER, data->temp[1]);

	data->last_updated = jiffies;
	data->valid = 1;
	}

	mutex_unlock(&data->update_lock);

	return data;
	}

	module_i2c_driver(w83l785ts_driver);

	MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
	MODULE_DESCRIPTION("W83L785TS-S driver");
	MODULE_LICENSE("GPL");