| /* 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, ®val); | 
 | 	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 S_IRUGO; | 
 | 	case hwmon_temp_max_hyst: | 
 | 	case hwmon_temp_max: | 
 | 		return S_IRUGO | S_IWUSR; | 
 | 	default: | 
 | 		return 0; | 
 | 	} | 
 | } | 
 |  | 
 | static u32 tmp102_chip_config[] = { | 
 | 	HWMON_C_REGISTER_TZ, | 
 | 	0 | 
 | }; | 
 |  | 
 | static const struct hwmon_channel_info tmp102_chip = { | 
 | 	.type = hwmon_chip, | 
 | 	.config = tmp102_chip_config, | 
 | }; | 
 |  | 
 | static u32 tmp102_temp_config[] = { | 
 | 	HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST, | 
 | 	0 | 
 | }; | 
 |  | 
 | static const struct hwmon_channel_info tmp102_temp = { | 
 | 	.type = hwmon_temp, | 
 | 	.config = tmp102_temp_config, | 
 | }; | 
 |  | 
 | static const struct hwmon_channel_info *tmp102_info[] = { | 
 | 	&tmp102_chip, | 
 | 	&tmp102_temp, | 
 | 	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_rw = 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, ®val); | 
 | 	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 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"); |