drivers/hwmon/tmp102.c - 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.
  */

 #include <linux/delay.h>
 #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>
 #include <linux/regmap.h>
 #include <linux/of.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

 #define TMP102_CONFREG_MASK	(TMP102_CONF_SD | TMP102_CONF_TM | \
 				 TMP102_CONF_POL | TMP102_CONF_F0 | \
 				 TMP102_CONF_F1 | TMP102_CONF_OS | \
 				 TMP102_CONF_EM | TMP102_CONF_AL | \
 				 TMP102_CONF_CR0 | TMP102_CONF_CR1)

 #define TMP102_CONFIG_CLEAR	(TMP102_CONF_SD | TMP102_CONF_OS | \
 				 TMP102_CONF_CR0)
 #define TMP102_CONFIG_SET	(TMP102_CONF_TM | TMP102_CONF_EM | \
 				 TMP102_CONF_CR1)

 #define CONVERSION_TIME_MS		35	/* in milli-seconds */

 struct tmp102 {
 	struct regmap *regmap;
 	u16 config_orig;
 	unsigned long ready_time;
 };

 /* 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 int tmp102_read(struct device *dev, enum hwmon_sensor_types type,
 		       u32 attr, int channel, long *temp)
 {
 	struct tmp102 *tmp102 = dev_get_drvdata(dev);
 	unsigned int regval;
 	int err, reg;

 	switch (attr) {
 	case hwmon_temp_input:
 		/* Is it too early to return a conversion ? */
 		if (time_before(jiffies, tmp102->ready_time)) {
 			dev_dbg(dev, "%s: Conversion not ready yet..\n", __func__);
 			return -EAGAIN;
 		}
 		reg = TMP102_TEMP_REG;
 		break;
 	case hwmon_temp_max_hyst:
 		reg = TMP102_TLOW_REG;
 		break;
 	case hwmon_temp_max:
 		reg = TMP102_THIGH_REG;
 		break;
 	default:
 		return -EOPNOTSUPP;
 	}

 	err = regmap_read(tmp102->regmap, reg, &regval);
 	if (err < 0)
 		return err;
 	*temp = tmp102_reg_to_mC(regval);

 	return 0;
 }

 static int tmp102_write(struct device *dev, enum hwmon_sensor_types type,
 			u32 attr, int channel, long temp)
 {
 	struct tmp102 *tmp102 = dev_get_drvdata(dev);
 	int reg;

 	switch (attr) {
 	case hwmon_temp_max_hyst:
 		reg = TMP102_TLOW_REG;
 		break;
 	case hwmon_temp_max:
 		reg = TMP102_THIGH_REG;
 		break;
 	default:
 		return -EOPNOTSUPP;
 	}

 	temp = clamp_val(temp, -256000, 255000);
 	return regmap_write(tmp102->regmap, reg, tmp102_mC_to_reg(temp));
 }

 static umode_t tmp102_is_visible(const void *data, enum hwmon_sensor_types type,
 				 u32 attr, int channel)
 {
 	if (type != hwmon_temp)
 		return 0;

 	switch (attr) {
 	case hwmon_temp_input:
 		return 0444;
 	case hwmon_temp_max_hyst:
 	case hwmon_temp_max:
 		return 0644;
 	default:
 		return 0;
 	}
 }

 static const struct hwmon_channel_info *tmp102_info[] = {
 	HWMON_CHANNEL_INFO(chip,
 			   HWMON_C_REGISTER_TZ),
 	HWMON_CHANNEL_INFO(temp,
 			   HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST),
 	NULL
 };

 static const struct hwmon_ops tmp102_hwmon_ops = {
 	.is_visible = tmp102_is_visible,
 	.read = tmp102_read,
 	.write = tmp102_write,
 };

 static const struct hwmon_chip_info tmp102_chip_info = {
 	.ops = &tmp102_hwmon_ops,
 	.info = tmp102_info,
 };

 static void tmp102_restore_config(void *data)
 {
 	struct tmp102 *tmp102 = data;

 	regmap_write(tmp102->regmap, TMP102_CONF_REG, tmp102->config_orig);
 }

 static bool tmp102_is_writeable_reg(struct device *dev, unsigned int reg)
 {
 	return reg != TMP102_TEMP_REG;
 }

 static bool tmp102_is_volatile_reg(struct device *dev, unsigned int reg)
 {
 	return reg == TMP102_TEMP_REG;
 }

 static const struct regmap_config tmp102_regmap_config = {
 	.reg_bits = 8,
 	.val_bits = 16,
 	.max_register = TMP102_THIGH_REG,
 	.writeable_reg = tmp102_is_writeable_reg,
 	.volatile_reg = tmp102_is_volatile_reg,
 	.val_format_endian = REGMAP_ENDIAN_BIG,
 	.cache_type = REGCACHE_RBTREE,
 	.use_single_read = true,
 	.use_single_write = true,
 };

 static int tmp102_probe(struct i2c_client *client,
 			const struct i2c_device_id *id)
 {
 	struct device *dev = &client->dev;
 	struct device *hwmon_dev;
 	struct tmp102 *tmp102;
 	unsigned int regval;
 	int err;

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

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

 	i2c_set_clientdata(client, tmp102);

 	tmp102->regmap = devm_regmap_init_i2c(client, &tmp102_regmap_config);
 	if (IS_ERR(tmp102->regmap))
 		return PTR_ERR(tmp102->regmap);

 	err = regmap_read(tmp102->regmap, TMP102_CONF_REG, &regval);
 	if (err < 0) {
 		dev_err(dev, "error reading config register\n");
 		return err;
 	}

 	if ((regval & ~TMP102_CONFREG_MASK) !=
 	    (TMP102_CONF_R0 | TMP102_CONF_R1)) {
 		dev_err(dev, "unexpected config register value\n");
 		return -ENODEV;
 	}

 	tmp102->config_orig = regval;

 	err = devm_add_action_or_reset(dev, tmp102_restore_config, tmp102);
 	if (err)
 		return err;

 	regval &= ~TMP102_CONFIG_CLEAR;
 	regval |= TMP102_CONFIG_SET;

 	err = regmap_write(tmp102->regmap, TMP102_CONF_REG, regval);
 	if (err < 0) {
 		dev_err(dev, "error writing config register\n");
 		return err;
 	}

 	/*
 	 * Mark that we are not ready with data until the first
 	 * conversion is complete
 	 */
 	tmp102->ready_time = jiffies + msecs_to_jiffies(CONVERSION_TIME_MS);

 	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
 							 tmp102,
 							 &tmp102_chip_info,
 							 NULL);
 	if (IS_ERR(hwmon_dev)) {
 		dev_dbg(dev, "unable to register hwmon device\n");
 		return PTR_ERR(hwmon_dev);
 	}
 	dev_info(dev, "initialized\n");

 	return 0;
 }

 #ifdef CONFIG_PM_SLEEP
 static int tmp102_suspend(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct tmp102 *tmp102 = i2c_get_clientdata(client);

 	return regmap_update_bits(tmp102->regmap, TMP102_CONF_REG,
 				  TMP102_CONF_SD, TMP102_CONF_SD);
 }

 static int tmp102_resume(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct tmp102 *tmp102 = i2c_get_clientdata(client);
 	int err;

 	err = regmap_update_bits(tmp102->regmap, TMP102_CONF_REG,
 				 TMP102_CONF_SD, 0);

 	tmp102->ready_time = jiffies + msecs_to_jiffies(CONVERSION_TIME_MS);

 	return err;
 }
 #endif /* CONFIG_PM */

 static SIMPLE_DEV_PM_OPS(tmp102_dev_pm_ops, tmp102_suspend, tmp102_resume);

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

 static const struct of_device_id __maybe_unused tmp102_of_match[] = {
 	{ .compatible = "ti,tmp102" },
 	{ },
 };
 MODULE_DEVICE_TABLE(of, tmp102_of_match);

 static struct i2c_driver tmp102_driver = {
 	.driver.name	= DRIVER_NAME,
 	.driver.of_match_table = of_match_ptr(tmp102_of_match),
 	.driver.pm	= &tmp102_dev_pm_ops,
 	.probe		= tmp102_probe,
 	.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.
	*/

	#include <linux/delay.h>
	#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>
	#include <linux/regmap.h>
	#include <linux/of.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

	#define TMP102_CONFREG_MASK (TMP102_CONF_SD \| TMP102_CONF_TM \| \
	TMP102_CONF_POL \| TMP102_CONF_F0 \| \
	TMP102_CONF_F1 \| TMP102_CONF_OS \| \
	TMP102_CONF_EM \| TMP102_CONF_AL \| \
	TMP102_CONF_CR0 \| TMP102_CONF_CR1)

	#define TMP102_CONFIG_CLEAR (TMP102_CONF_SD \| TMP102_CONF_OS \| \
	TMP102_CONF_CR0)
	#define TMP102_CONFIG_SET (TMP102_CONF_TM \| TMP102_CONF_EM \| \
	TMP102_CONF_CR1)

	#define CONVERSION_TIME_MS 35 /* in milli-seconds */

	struct tmp102 {
	struct regmap *regmap;
	u16 config_orig;
	unsigned long ready_time;
	};

	/* 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 int tmp102_read(struct device *dev, enum hwmon_sensor_types type,
	u32 attr, int channel, long *temp)
	{
	struct tmp102 *tmp102 = dev_get_drvdata(dev);
	unsigned int regval;
	int err, reg;

	switch (attr) {
	case hwmon_temp_input:
	/* Is it too early to return a conversion ? */
	if (time_before(jiffies, tmp102->ready_time)) {
	dev_dbg(dev, "%s: Conversion not ready yet..\n", __func__);
	return -EAGAIN;
	}
	reg = TMP102_TEMP_REG;
	break;
	case hwmon_temp_max_hyst:
	reg = TMP102_TLOW_REG;
	break;
	case hwmon_temp_max:
	reg = TMP102_THIGH_REG;
	break;
	default:
	return -EOPNOTSUPP;
	}

	err = regmap_read(tmp102->regmap, reg, &regval);
	if (err < 0)
	return err;
	*temp = tmp102_reg_to_mC(regval);

	return 0;
	}

	static int tmp102_write(struct device *dev, enum hwmon_sensor_types type,
	u32 attr, int channel, long temp)
	{
	struct tmp102 *tmp102 = dev_get_drvdata(dev);
	int reg;

	switch (attr) {
	case hwmon_temp_max_hyst:
	reg = TMP102_TLOW_REG;
	break;
	case hwmon_temp_max:
	reg = TMP102_THIGH_REG;
	break;
	default:
	return -EOPNOTSUPP;
	}

	temp = clamp_val(temp, -256000, 255000);
	return regmap_write(tmp102->regmap, reg, tmp102_mC_to_reg(temp));
	}

	static umode_t tmp102_is_visible(const void *data, enum hwmon_sensor_types type,
	u32 attr, int channel)
	{
	if (type != hwmon_temp)
	return 0;

	switch (attr) {
	case hwmon_temp_input:
	return 0444;
	case hwmon_temp_max_hyst:
	case hwmon_temp_max:
	return 0644;
	default:
	return 0;
	}
	}

	static const struct hwmon_channel_info *tmp102_info[] = {
	HWMON_CHANNEL_INFO(chip,
	HWMON_C_REGISTER_TZ),
	HWMON_CHANNEL_INFO(temp,
	HWMON_T_INPUT \| HWMON_T_MAX \| HWMON_T_MAX_HYST),
	NULL
	};

	static const struct hwmon_ops tmp102_hwmon_ops = {
	.is_visible = tmp102_is_visible,
	.read = tmp102_read,
	.write = tmp102_write,
	};

	static const struct hwmon_chip_info tmp102_chip_info = {
	.ops = &tmp102_hwmon_ops,
	.info = tmp102_info,
	};

	static void tmp102_restore_config(void *data)
	{
	struct tmp102 *tmp102 = data;

	regmap_write(tmp102->regmap, TMP102_CONF_REG, tmp102->config_orig);
	}

	static bool tmp102_is_writeable_reg(struct device *dev, unsigned int reg)
	{
	return reg != TMP102_TEMP_REG;
	}

	static bool tmp102_is_volatile_reg(struct device *dev, unsigned int reg)
	{
	return reg == TMP102_TEMP_REG;
	}

	static const struct regmap_config tmp102_regmap_config = {
	.reg_bits = 8,
	.val_bits = 16,
	.max_register = TMP102_THIGH_REG,
	.writeable_reg = tmp102_is_writeable_reg,
	.volatile_reg = tmp102_is_volatile_reg,
	.val_format_endian = REGMAP_ENDIAN_BIG,
	.cache_type = REGCACHE_RBTREE,
	.use_single_read = true,
	.use_single_write = true,
	};

	static int tmp102_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	struct device *dev = &client->dev;
	struct device *hwmon_dev;
	struct tmp102 *tmp102;
	unsigned int regval;
	int err;

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

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

	i2c_set_clientdata(client, tmp102);

	tmp102->regmap = devm_regmap_init_i2c(client, &tmp102_regmap_config);
	if (IS_ERR(tmp102->regmap))
	return PTR_ERR(tmp102->regmap);

	err = regmap_read(tmp102->regmap, TMP102_CONF_REG, &regval);
	if (err < 0) {
	dev_err(dev, "error reading config register\n");
	return err;
	}

	if ((regval & ~TMP102_CONFREG_MASK) !=
	(TMP102_CONF_R0 \| TMP102_CONF_R1)) {
	dev_err(dev, "unexpected config register value\n");
	return -ENODEV;
	}

	tmp102->config_orig = regval;

	err = devm_add_action_or_reset(dev, tmp102_restore_config, tmp102);
	if (err)
	return err;

	regval &= ~TMP102_CONFIG_CLEAR;
	regval \|= TMP102_CONFIG_SET;

	err = regmap_write(tmp102->regmap, TMP102_CONF_REG, regval);
	if (err < 0) {
	dev_err(dev, "error writing config register\n");
	return err;
	}

	/*
	* Mark that we are not ready with data until the first
	* conversion is complete
	*/
	tmp102->ready_time = jiffies + msecs_to_jiffies(CONVERSION_TIME_MS);

	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
	tmp102,
	&tmp102_chip_info,
	NULL);
	if (IS_ERR(hwmon_dev)) {
	dev_dbg(dev, "unable to register hwmon device\n");
	return PTR_ERR(hwmon_dev);
	}
	dev_info(dev, "initialized\n");

	return 0;
	}

	#ifdef CONFIG_PM_SLEEP
	static int tmp102_suspend(struct device *dev)
	{
	struct i2c_client *client = to_i2c_client(dev);
	struct tmp102 *tmp102 = i2c_get_clientdata(client);

	return regmap_update_bits(tmp102->regmap, TMP102_CONF_REG,
	TMP102_CONF_SD, TMP102_CONF_SD);
	}

	static int tmp102_resume(struct device *dev)
	{
	struct i2c_client *client = to_i2c_client(dev);
	struct tmp102 *tmp102 = i2c_get_clientdata(client);
	int err;

	err = regmap_update_bits(tmp102->regmap, TMP102_CONF_REG,
	TMP102_CONF_SD, 0);

	tmp102->ready_time = jiffies + msecs_to_jiffies(CONVERSION_TIME_MS);

	return err;
	}
	#endif /* CONFIG_PM */

	static SIMPLE_DEV_PM_OPS(tmp102_dev_pm_ops, tmp102_suspend, tmp102_resume);

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

	static const struct of_device_id __maybe_unused tmp102_of_match[] = {
	{ .compatible = "ti,tmp102" },
	{ },
	};
	MODULE_DEVICE_TABLE(of, tmp102_of_match);

	static struct i2c_driver tmp102_driver = {
	.driver.name = DRIVER_NAME,
	.driver.of_match_table = of_match_ptr(tmp102_of_match),
	.driver.pm = &tmp102_dev_pm_ops,
	.probe = tmp102_probe,
	.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");