drivers/hwmon/tmp102.c - maze/linux - Git at Google

 /* Texas Instruments TMP102 SMBus temperature sensor driver
  *
  * Copyright (C) 2010 Steven King <sfking@fdwdc.com>
  *
  * 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., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA
  */

 #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/mutex.h>
 #include <linux/device.h>
 #include <linux/jiffies.h>

 #define	DRIVER_NAME "tmp102"

 #define	TMP102_TEMP_REG			0x00
 #define	TMP102_CONF_REG			0x01
 /* note: these bit definitions are byte swapped */
 #define		TMP102_CONF_SD		0x0100
 #define		TMP102_CONF_TM		0x0200
 #define		TMP102_CONF_POL		0x0400
 #define		TMP102_CONF_F0		0x0800
 #define		TMP102_CONF_F1		0x1000
 #define		TMP102_CONF_R0		0x2000
 #define		TMP102_CONF_R1		0x4000
 #define		TMP102_CONF_OS		0x8000
 #define		TMP102_CONF_EM		0x0010
 #define		TMP102_CONF_AL		0x0020
 #define		TMP102_CONF_CR0		0x0040
 #define		TMP102_CONF_CR1		0x0080
 #define	TMP102_TLOW_REG			0x02
 #define	TMP102_THIGH_REG		0x03

 struct tmp102 {
 	struct device *hwmon_dev;
 	struct mutex lock;
 	u16 config_orig;
 	unsigned long last_update;
 	int temp[3];
 };

 /* convert left adjusted 13-bit TMP102 register value to milliCelsius */
 static inline int tmp102_reg_to_mC(s16 val)
 {
 	return ((val & ~0x01) * 1000) / 128;
 }

 /* convert milliCelsius to left adjusted 13-bit TMP102 register value */
 static inline u16 tmp102_mC_to_reg(int val)
 {
 	return (val * 128) / 1000;
 }

 static const u8 tmp102_reg[] = {
 	TMP102_TEMP_REG,
 	TMP102_TLOW_REG,
 	TMP102_THIGH_REG,
 };

 static struct tmp102 *tmp102_update_device(struct i2c_client *client)
 {
 	struct tmp102 *tmp102 = i2c_get_clientdata(client);

 	mutex_lock(&tmp102->lock);
 	if (time_after(jiffies, tmp102->last_update + HZ / 3)) {
 		int i;
 		for (i = 0; i < ARRAY_SIZE(tmp102->temp); ++i) {
 			int status = i2c_smbus_read_word_swapped(client,
 								 tmp102_reg[i]);
 			if (status > -1)
 				tmp102->temp[i] = tmp102_reg_to_mC(status);
 		}
 		tmp102->last_update = jiffies;
 	}
 	mutex_unlock(&tmp102->lock);
 	return tmp102;
 }

 static ssize_t tmp102_show_temp(struct device *dev,
 				struct device_attribute *attr,
 				char *buf)
 {
 	struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
 	struct tmp102 *tmp102 = tmp102_update_device(to_i2c_client(dev));

 	return sprintf(buf, "%d\n", tmp102->temp[sda->index]);
 }

 static ssize_t tmp102_set_temp(struct device *dev,
 			       struct device_attribute *attr,
 			       const char *buf, size_t count)
 {
 	struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
 	struct i2c_client *client = to_i2c_client(dev);
 	struct tmp102 *tmp102 = i2c_get_clientdata(client);
 	long val;
 	int status;

 	if (kstrtol(buf, 10, &val) < 0)
 		return -EINVAL;
 	val = clamp_val(val, -256000, 255000);

 	mutex_lock(&tmp102->lock);
 	tmp102->temp[sda->index] = val;
 	status = i2c_smbus_write_word_swapped(client, tmp102_reg[sda->index],
 					      tmp102_mC_to_reg(val));
 	mutex_unlock(&tmp102->lock);
 	return status ? : count;
 }

 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, tmp102_show_temp, NULL , 0);

 static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO, tmp102_show_temp,
 			  tmp102_set_temp, 1);

 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, tmp102_show_temp,
 			  tmp102_set_temp, 2);

 static struct attribute *tmp102_attributes[] = {
 	&sensor_dev_attr_temp1_input.dev_attr.attr,
 	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
 	&sensor_dev_attr_temp1_max.dev_attr.attr,
 	NULL
 };

 static const struct attribute_group tmp102_attr_group = {
 	.attrs = tmp102_attributes,
 };

 #define TMP102_CONFIG  (TMP102_CONF_TM | TMP102_CONF_EM | TMP102_CONF_CR1)
 #define TMP102_CONFIG_RD_ONLY (TMP102_CONF_R0 | TMP102_CONF_R1 | TMP102_CONF_AL)

 static int tmp102_probe(struct i2c_client *client,
 				  const struct i2c_device_id *id)
 {
 	struct tmp102 *tmp102;
 	int status;

 	if (!i2c_check_functionality(client->adapter,
 				     I2C_FUNC_SMBUS_WORD_DATA)) {
 		dev_err(&client->dev,
 			"adapter doesn't support SMBus word transactions\n");
 		return -ENODEV;
 	}

 	tmp102 = devm_kzalloc(&client->dev, sizeof(*tmp102), GFP_KERNEL);
 	if (!tmp102)
 		return -ENOMEM;

 	i2c_set_clientdata(client, tmp102);

 	status = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
 	if (status < 0) {
 		dev_err(&client->dev, "error reading config register\n");
 		return status;
 	}
 	tmp102->config_orig = status;
 	status = i2c_smbus_write_word_swapped(client, TMP102_CONF_REG,
 					      TMP102_CONFIG);
 	if (status < 0) {
 		dev_err(&client->dev, "error writing config register\n");
 		goto fail_restore_config;
 	}
 	status = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
 	if (status < 0) {
 		dev_err(&client->dev, "error reading config register\n");
 		goto fail_restore_config;
 	}
 	status &= ~TMP102_CONFIG_RD_ONLY;
 	if (status != TMP102_CONFIG) {
 		dev_err(&client->dev, "config settings did not stick\n");
 		status = -ENODEV;
 		goto fail_restore_config;
 	}
 	tmp102->last_update = jiffies - HZ;
 	mutex_init(&tmp102->lock);

 	status = sysfs_create_group(&client->dev.kobj, &tmp102_attr_group);
 	if (status) {
 		dev_dbg(&client->dev, "could not create sysfs files\n");
 		goto fail_restore_config;
 	}
 	tmp102->hwmon_dev = hwmon_device_register(&client->dev);
 	if (IS_ERR(tmp102->hwmon_dev)) {
 		dev_dbg(&client->dev, "unable to register hwmon device\n");
 		status = PTR_ERR(tmp102->hwmon_dev);
 		goto fail_remove_sysfs;
 	}

 	dev_info(&client->dev, "initialized\n");

 	return 0;

 fail_remove_sysfs:
 	sysfs_remove_group(&client->dev.kobj, &tmp102_attr_group);
 fail_restore_config:
 	i2c_smbus_write_word_swapped(client, TMP102_CONF_REG,
 				     tmp102->config_orig);
 	return status;
 }

 static int tmp102_remove(struct i2c_client *client)
 {
 	struct tmp102 *tmp102 = i2c_get_clientdata(client);

 	hwmon_device_unregister(tmp102->hwmon_dev);
 	sysfs_remove_group(&client->dev.kobj, &tmp102_attr_group);

 	/* Stop monitoring if device was stopped originally */
 	if (tmp102->config_orig & TMP102_CONF_SD) {
 		int config;

 		config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
 		if (config >= 0)
 			i2c_smbus_write_word_swapped(client, TMP102_CONF_REG,
 						     config | TMP102_CONF_SD);
 	}

 	return 0;
 }

 #ifdef CONFIG_PM
 static int tmp102_suspend(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	int config;

 	config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
 	if (config < 0)
 		return config;

 	config |= TMP102_CONF_SD;
 	return i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, config);
 }

 static int tmp102_resume(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	int config;

 	config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
 	if (config < 0)
 		return config;

 	config &= ~TMP102_CONF_SD;
 	return i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, config);
 }

 static const struct dev_pm_ops tmp102_dev_pm_ops = {
 	.suspend	= tmp102_suspend,
 	.resume		= tmp102_resume,
 };

 #define TMP102_DEV_PM_OPS (&tmp102_dev_pm_ops)
 #else
 #define	TMP102_DEV_PM_OPS NULL
 #endif /* CONFIG_PM */

 static const struct i2c_device_id tmp102_id[] = {
 	{ "tmp102", 0 },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, tmp102_id);

 static struct i2c_driver tmp102_driver = {
 	.driver.name	= DRIVER_NAME,
 	.driver.pm	= TMP102_DEV_PM_OPS,
 	.probe		= tmp102_probe,
 	.remove		= tmp102_remove,
 	.id_table	= tmp102_id,
 };

 module_i2c_driver(tmp102_driver);

 MODULE_AUTHOR("Steven King <sfking@fdwdc.com>");
 MODULE_DESCRIPTION("Texas Instruments TMP102 temperature sensor driver");
 MODULE_LICENSE("GPL");
	/* Texas Instruments TMP102 SMBus temperature sensor driver
	*
	* Copyright (C) 2010 Steven King <sfking@fdwdc.com>
	*
	* 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., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA
	*/

	#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/mutex.h>
	#include <linux/device.h>
	#include <linux/jiffies.h>

	#define DRIVER_NAME "tmp102"

	#define TMP102_TEMP_REG 0x00
	#define TMP102_CONF_REG 0x01
	/* note: these bit definitions are byte swapped */
	#define TMP102_CONF_SD 0x0100
	#define TMP102_CONF_TM 0x0200
	#define TMP102_CONF_POL 0x0400
	#define TMP102_CONF_F0 0x0800
	#define TMP102_CONF_F1 0x1000
	#define TMP102_CONF_R0 0x2000
	#define TMP102_CONF_R1 0x4000
	#define TMP102_CONF_OS 0x8000
	#define TMP102_CONF_EM 0x0010
	#define TMP102_CONF_AL 0x0020
	#define TMP102_CONF_CR0 0x0040
	#define TMP102_CONF_CR1 0x0080
	#define TMP102_TLOW_REG 0x02
	#define TMP102_THIGH_REG 0x03

	struct tmp102 {
	struct device *hwmon_dev;
	struct mutex lock;
	u16 config_orig;
	unsigned long last_update;
	int temp[3];
	};

	/* convert left adjusted 13-bit TMP102 register value to milliCelsius */
	static inline int tmp102_reg_to_mC(s16 val)
	{
	return ((val & ~0x01) * 1000) / 128;
	}

	/* convert milliCelsius to left adjusted 13-bit TMP102 register value */
	static inline u16 tmp102_mC_to_reg(int val)
	{
	return (val * 128) / 1000;
	}

	static const u8 tmp102_reg[] = {
	TMP102_TEMP_REG,
	TMP102_TLOW_REG,
	TMP102_THIGH_REG,
	};

	static struct tmp102 tmp102_update_device(struct i2c_client client)
	{
	struct tmp102 *tmp102 = i2c_get_clientdata(client);

	mutex_lock(&tmp102->lock);
	if (time_after(jiffies, tmp102->last_update + HZ / 3)) {
	int i;
	for (i = 0; i < ARRAY_SIZE(tmp102->temp); ++i) {
	int status = i2c_smbus_read_word_swapped(client,
	tmp102_reg[i]);
	if (status > -1)
	tmp102->temp[i] = tmp102_reg_to_mC(status);
	}
	tmp102->last_update = jiffies;
	}
	mutex_unlock(&tmp102->lock);
	return tmp102;
	}

	static ssize_t tmp102_show_temp(struct device *dev,
	struct device_attribute *attr,
	char *buf)
	{
	struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
	struct tmp102 *tmp102 = tmp102_update_device(to_i2c_client(dev));

	return sprintf(buf, "%d\n", tmp102->temp[sda->index]);
	}

	static ssize_t tmp102_set_temp(struct device *dev,
	struct device_attribute *attr,
	const char *buf, size_t count)
	{
	struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
	struct i2c_client *client = to_i2c_client(dev);
	struct tmp102 *tmp102 = i2c_get_clientdata(client);
	long val;
	int status;

	if (kstrtol(buf, 10, &val) < 0)
	return -EINVAL;
	val = clamp_val(val, -256000, 255000);

	mutex_lock(&tmp102->lock);
	tmp102->temp[sda->index] = val;
	status = i2c_smbus_write_word_swapped(client, tmp102_reg[sda->index],
	tmp102_mC_to_reg(val));
	mutex_unlock(&tmp102->lock);
	return status ? : count;
	}

	static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, tmp102_show_temp, NULL , 0);

	static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR \| S_IRUGO, tmp102_show_temp,
	tmp102_set_temp, 1);

	static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR \| S_IRUGO, tmp102_show_temp,
	tmp102_set_temp, 2);

	static struct attribute *tmp102_attributes[] = {
	&sensor_dev_attr_temp1_input.dev_attr.attr,
	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
	&sensor_dev_attr_temp1_max.dev_attr.attr,
	NULL
	};

	static const struct attribute_group tmp102_attr_group = {
	.attrs = tmp102_attributes,
	};

	#define TMP102_CONFIG (TMP102_CONF_TM \| TMP102_CONF_EM \| TMP102_CONF_CR1)
	#define TMP102_CONFIG_RD_ONLY (TMP102_CONF_R0 \| TMP102_CONF_R1 \| TMP102_CONF_AL)

	static int tmp102_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	struct tmp102 *tmp102;
	int status;

	if (!i2c_check_functionality(client->adapter,
	I2C_FUNC_SMBUS_WORD_DATA)) {
	dev_err(&client->dev,
	"adapter doesn't support SMBus word transactions\n");
	return -ENODEV;
	}

	tmp102 = devm_kzalloc(&client->dev, sizeof(*tmp102), GFP_KERNEL);
	if (!tmp102)
	return -ENOMEM;

	i2c_set_clientdata(client, tmp102);

	status = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
	if (status < 0) {
	dev_err(&client->dev, "error reading config register\n");
	return status;
	}
	tmp102->config_orig = status;
	status = i2c_smbus_write_word_swapped(client, TMP102_CONF_REG,
	TMP102_CONFIG);
	if (status < 0) {
	dev_err(&client->dev, "error writing config register\n");
	goto fail_restore_config;
	}
	status = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
	if (status < 0) {
	dev_err(&client->dev, "error reading config register\n");
	goto fail_restore_config;
	}
	status &= ~TMP102_CONFIG_RD_ONLY;
	if (status != TMP102_CONFIG) {
	dev_err(&client->dev, "config settings did not stick\n");
	status = -ENODEV;
	goto fail_restore_config;
	}
	tmp102->last_update = jiffies - HZ;
	mutex_init(&tmp102->lock);

	status = sysfs_create_group(&client->dev.kobj, &tmp102_attr_group);
	if (status) {
	dev_dbg(&client->dev, "could not create sysfs files\n");
	goto fail_restore_config;
	}
	tmp102->hwmon_dev = hwmon_device_register(&client->dev);
	if (IS_ERR(tmp102->hwmon_dev)) {
	dev_dbg(&client->dev, "unable to register hwmon device\n");
	status = PTR_ERR(tmp102->hwmon_dev);
	goto fail_remove_sysfs;
	}

	dev_info(&client->dev, "initialized\n");

	return 0;

	fail_remove_sysfs:
	sysfs_remove_group(&client->dev.kobj, &tmp102_attr_group);
	fail_restore_config:
	i2c_smbus_write_word_swapped(client, TMP102_CONF_REG,
	tmp102->config_orig);
	return status;
	}

	static int tmp102_remove(struct i2c_client *client)
	{
	struct tmp102 *tmp102 = i2c_get_clientdata(client);

	hwmon_device_unregister(tmp102->hwmon_dev);
	sysfs_remove_group(&client->dev.kobj, &tmp102_attr_group);

	/* Stop monitoring if device was stopped originally */
	if (tmp102->config_orig & TMP102_CONF_SD) {
	int config;

	config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
	if (config >= 0)
	i2c_smbus_write_word_swapped(client, TMP102_CONF_REG,
	config \| TMP102_CONF_SD);
	}

	return 0;
	}

	#ifdef CONFIG_PM
	static int tmp102_suspend(struct device *dev)
	{
	struct i2c_client *client = to_i2c_client(dev);
	int config;

	config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
	if (config < 0)
	return config;

	config \|= TMP102_CONF_SD;
	return i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, config);
	}

	static int tmp102_resume(struct device *dev)
	{
	struct i2c_client *client = to_i2c_client(dev);
	int config;

	config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
	if (config < 0)
	return config;

	config &= ~TMP102_CONF_SD;
	return i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, config);
	}

	static const struct dev_pm_ops tmp102_dev_pm_ops = {
	.suspend = tmp102_suspend,
	.resume = tmp102_resume,
	};

	#define TMP102_DEV_PM_OPS (&tmp102_dev_pm_ops)
	#else
	#define TMP102_DEV_PM_OPS NULL
	#endif /* CONFIG_PM */

	static const struct i2c_device_id tmp102_id[] = {
	{ "tmp102", 0 },
	{ }
	};
	MODULE_DEVICE_TABLE(i2c, tmp102_id);

	static struct i2c_driver tmp102_driver = {
	.driver.name = DRIVER_NAME,
	.driver.pm = TMP102_DEV_PM_OPS,
	.probe = tmp102_probe,
	.remove = tmp102_remove,
	.id_table = tmp102_id,
	};

	module_i2c_driver(tmp102_driver);

	MODULE_AUTHOR("Steven King <sfking@fdwdc.com>");
	MODULE_DESCRIPTION("Texas Instruments TMP102 temperature sensor driver");
	MODULE_LICENSE("GPL");