[linux.git] / drivers / hwmon / tmp108.c

/* Texas Instruments TMP108 SMBus temperature sensor driver
 *
 * Copyright (C) 2016 John Muir <[email protected]>
 *
 * 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/device.h>
#include <linux/err.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/jiffies.h>
#include <linux/regmap.h>
#include <linux/slab.h>

#define	DRIVER_NAME "tmp108"

#define	TMP108_REG_TEMP		0x00
#define	TMP108_REG_CONF		0x01
#define	TMP108_REG_TLOW		0x02
#define	TMP108_REG_THIGH	0x03

#define TMP108_TEMP_MIN_MC	-50000 /* Minimum millicelcius. */
#define TMP108_TEMP_MAX_MC	127937 /* Maximum millicelcius. */

/* Configuration register bits.
 * Note: these bit definitions are byte swapped.
 */
#define TMP108_CONF_M0		0x0100 /* Sensor mode. */
#define TMP108_CONF_M1		0x0200
#define TMP108_CONF_TM		0x0400 /* Thermostat mode. */
#define TMP108_CONF_FL		0x0800 /* Watchdog flag - TLOW */
#define TMP108_CONF_FH		0x1000 /* Watchdog flag - THIGH */
#define TMP108_CONF_CR0		0x2000 /* Conversion rate. */
#define TMP108_CONF_CR1		0x4000
#define TMP108_CONF_ID		0x8000
#define TMP108_CONF_HYS0	0x0010 /* Hysteresis. */
#define TMP108_CONF_HYS1	0x0020
#define TMP108_CONF_POL		0x0080 /* Polarity of alert. */

/* Defaults set by the hardware upon reset. */
#define TMP108_CONF_DEFAULTS		(TMP108_CONF_CR0 | TMP108_CONF_TM |\
					 TMP108_CONF_HYS0 | TMP108_CONF_M1)
/* These bits are read-only. */
#define TMP108_CONF_READ_ONLY		(TMP108_CONF_FL | TMP108_CONF_FH |\
					 TMP108_CONF_ID)

#define TMP108_CONF_MODE_MASK		(TMP108_CONF_M0|TMP108_CONF_M1)
#define TMP108_MODE_SHUTDOWN		0x0000
#define TMP108_MODE_ONE_SHOT		TMP108_CONF_M0
#define TMP108_MODE_CONTINUOUS		TMP108_CONF_M1		/* Default */
					/* When M1 is set, M0 is ignored. */

#define TMP108_CONF_CONVRATE_MASK	(TMP108_CONF_CR0|TMP108_CONF_CR1)
#define TMP108_CONVRATE_0P25HZ		0x0000
#define TMP108_CONVRATE_1HZ		TMP108_CONF_CR0		/* Default */
#define TMP108_CONVRATE_4HZ		TMP108_CONF_CR1
#define TMP108_CONVRATE_16HZ		(TMP108_CONF_CR0|TMP108_CONF_CR1)

#define TMP108_CONF_HYSTERESIS_MASK	(TMP108_CONF_HYS0|TMP108_CONF_HYS1)
#define TMP108_HYSTERESIS_0C		0x0000
#define TMP108_HYSTERESIS_1C		TMP108_CONF_HYS0	/* Default */
#define TMP108_HYSTERESIS_2C		TMP108_CONF_HYS1
#define TMP108_HYSTERESIS_4C		(TMP108_CONF_HYS0|TMP108_CONF_HYS1)

#define TMP108_CONVERSION_TIME_MS	30	/* in milli-seconds */

struct tmp108 {
	struct regmap *regmap;
	u16 orig_config;
	unsigned long ready_time;
};

/* convert 12-bit TMP108 register value to milliCelsius */
static inline int tmp108_temp_reg_to_mC(s16 val)
{
	return (val & ~0x0f) * 1000 / 256;
}

/* convert milliCelsius to left adjusted 12-bit TMP108 register value */
static inline u16 tmp108_mC_to_temp_reg(int val)
{
	return (val * 256) / 1000;
}

static int tmp108_read(struct device *dev, enum hwmon_sensor_types type,
		       u32 attr, int channel, long *temp)
{
	struct tmp108 *tmp108 = dev_get_drvdata(dev);
	unsigned int regval;
	int err, hyst;

	if (type == hwmon_chip) {
		if (attr == hwmon_chip_update_interval) {
			err = regmap_read(tmp108->regmap, TMP108_REG_CONF,
					  &regval);
			if (err < 0)
				return err;
			switch (regval & TMP108_CONF_CONVRATE_MASK) {
			case TMP108_CONVRATE_0P25HZ:
			default:
				*temp = 4000;
				break;
			case TMP108_CONVRATE_1HZ:
				*temp = 1000;
				break;
			case TMP108_CONVRATE_4HZ:
				*temp = 250;
				break;
			case TMP108_CONVRATE_16HZ:
				*temp = 63;
				break;
			}
			return 0;
		}
		return -EOPNOTSUPP;
	}

	switch (attr) {
	case hwmon_temp_input:
		/* Is it too early to return a conversion ? */
		if (time_before(jiffies, tmp108->ready_time)) {
			dev_dbg(dev, "%s: Conversion not ready yet..\n",
				__func__);
			return -EAGAIN;
		}
		err = regmap_read(tmp108->regmap, TMP108_REG_TEMP, &regval);
		if (err < 0)
			return err;
		*temp = tmp108_temp_reg_to_mC(regval);
		break;
	case hwmon_temp_min:
	case hwmon_temp_max:
		err = regmap_read(tmp108->regmap, attr == hwmon_temp_min ?
				  TMP108_REG_TLOW : TMP108_REG_THIGH, &regval);
		if (err < 0)
			return err;
		*temp = tmp108_temp_reg_to_mC(regval);
		break;
	case hwmon_temp_min_alarm:
	case hwmon_temp_max_alarm:
		err = regmap_read(tmp108->regmap, TMP108_REG_CONF, &regval);
		if (err < 0)
			return err;
		*temp = !!(regval & (attr == hwmon_temp_min_alarm ?
				     TMP108_CONF_FL : TMP108_CONF_FH));
		break;
	case hwmon_temp_min_hyst:
	case hwmon_temp_max_hyst:
		err = regmap_read(tmp108->regmap, TMP108_REG_CONF, &regval);
		if (err < 0)
			return err;
		switch (regval & TMP108_CONF_HYSTERESIS_MASK) {
		case TMP108_HYSTERESIS_0C:
		default:
			hyst = 0;
			break;
		case TMP108_HYSTERESIS_1C:
			hyst = 1000;
			break;
		case TMP108_HYSTERESIS_2C:
			hyst = 2000;
			break;
		case TMP108_HYSTERESIS_4C:
			hyst = 4000;
			break;
		}
		err = regmap_read(tmp108->regmap, attr == hwmon_temp_min_hyst ?
				  TMP108_REG_TLOW : TMP108_REG_THIGH, &regval);
		if (err < 0)
			return err;
		*temp = tmp108_temp_reg_to_mC(regval);
		if (attr == hwmon_temp_min_hyst)
			*temp += hyst;
		else
			*temp -= hyst;
		break;
	default:
		return -EOPNOTSUPP;
	}

	return 0;
}

static int tmp108_write(struct device *dev, enum hwmon_sensor_types type,
			u32 attr, int channel, long temp)
{
	struct tmp108 *tmp108 = dev_get_drvdata(dev);
	u32 regval, mask;
	int err;

	if (type == hwmon_chip) {
		if (attr == hwmon_chip_update_interval) {
			if (temp < 156)
				mask = TMP108_CONVRATE_16HZ;
			else if (temp < 625)
				mask = TMP108_CONVRATE_4HZ;
			else if (temp < 2500)
				mask = TMP108_CONVRATE_1HZ;
			else
				mask = TMP108_CONVRATE_0P25HZ;
			return regmap_update_bits(tmp108->regmap,
						  TMP108_REG_CONF,
						  TMP108_CONF_CONVRATE_MASK,
						  mask);
		}
		return -EOPNOTSUPP;
	}

	switch (attr) {
	case hwmon_temp_min:
	case hwmon_temp_max:
		temp = clamp_val(temp, TMP108_TEMP_MIN_MC, TMP108_TEMP_MAX_MC);
		return regmap_write(tmp108->regmap,
				    attr == hwmon_temp_min ?
					TMP108_REG_TLOW : TMP108_REG_THIGH,
				    tmp108_mC_to_temp_reg(temp));
	case hwmon_temp_min_hyst:
	case hwmon_temp_max_hyst:
		temp = clamp_val(temp, TMP108_TEMP_MIN_MC, TMP108_TEMP_MAX_MC);
		err = regmap_read(tmp108->regmap,
				  attr == hwmon_temp_min_hyst ?
					TMP108_REG_TLOW : TMP108_REG_THIGH,
				  &regval);
		if (err < 0)
			return err;
		if (attr == hwmon_temp_min_hyst)
			temp -= tmp108_temp_reg_to_mC(regval);
		else
			temp = tmp108_temp_reg_to_mC(regval) - temp;
		if (temp < 500)
			mask = TMP108_HYSTERESIS_0C;
		else if (temp < 1500)
			mask = TMP108_HYSTERESIS_1C;
		else if (temp < 3000)
			mask = TMP108_HYSTERESIS_2C;
		else
			mask = TMP108_HYSTERESIS_4C;
		return regmap_update_bits(tmp108->regmap, TMP108_REG_CONF,
					  TMP108_CONF_HYSTERESIS_MASK, mask);
	default:
		return -EOPNOTSUPP;
	}
}

static umode_t tmp108_is_visible(const void *data, enum hwmon_sensor_types type,
				 u32 attr, int channel)
{
	if (type == hwmon_chip && attr == hwmon_chip_update_interval)
		return 0644;

	if (type != hwmon_temp)
		return 0;

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

static u32 tmp108_chip_config[] = {
	HWMON_C_REGISTER_TZ | HWMON_C_UPDATE_INTERVAL,
	0
};

static const struct hwmon_channel_info tmp108_chip = {
	.type = hwmon_chip,
	.config = tmp108_chip_config,
};

static u32 tmp108_temp_config[] = {
	HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN | HWMON_T_MIN_HYST
		| HWMON_T_MAX_HYST | HWMON_T_MIN_ALARM | HWMON_T_MAX_ALARM,
	0
};

static const struct hwmon_channel_info tmp108_temp = {
	.type = hwmon_temp,
	.config = tmp108_temp_config,
};

static const struct hwmon_channel_info *tmp108_info[] = {
	&tmp108_chip,
	&tmp108_temp,
	NULL
};

static const struct hwmon_ops tmp108_hwmon_ops = {
	.is_visible = tmp108_is_visible,
	.read = tmp108_read,
	.write = tmp108_write,
};

static const struct hwmon_chip_info tmp108_chip_info = {
	.ops = &tmp108_hwmon_ops,
	.info = tmp108_info,
};

static void tmp108_restore_config(void *data)
{
	struct tmp108 *tmp108 = data;

	regmap_write(tmp108->regmap, TMP108_REG_CONF, tmp108->orig_config);
}

static bool tmp108_is_writeable_reg(struct device *dev, unsigned int reg)
{
	return reg != TMP108_REG_TEMP;
}

static bool tmp108_is_volatile_reg(struct device *dev, unsigned int reg)
{
	/* Configuration register must be volatile to enable FL and FH. */
	return reg == TMP108_REG_TEMP || reg == TMP108_REG_CONF;
}

static const struct regmap_config tmp108_regmap_config = {
	.reg_bits = 8,
	.val_bits = 16,
	.max_register = TMP108_REG_THIGH,
	.writeable_reg = tmp108_is_writeable_reg,
	.volatile_reg = tmp108_is_volatile_reg,
	.val_format_endian = REGMAP_ENDIAN_BIG,
	.cache_type = REGCACHE_RBTREE,
	.use_single_read = true,
	.use_single_write = true,
};

static int tmp108_probe(struct i2c_client *client,
			const struct i2c_device_id *id)
{
	struct device *dev = &client->dev;
	struct device *hwmon_dev;
	struct tmp108 *tmp108;
	int err;
	u32 config;

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

	tmp108 = devm_kzalloc(dev, sizeof(*tmp108), GFP_KERNEL);
	if (!tmp108)
		return -ENOMEM;

	dev_set_drvdata(dev, tmp108);

	tmp108->regmap = devm_regmap_init_i2c(client, &tmp108_regmap_config);
	if (IS_ERR(tmp108->regmap)) {
		err = PTR_ERR(tmp108->regmap);
		dev_err(dev, "regmap init failed: %d", err);
		return err;
	}

	err = regmap_read(tmp108->regmap, TMP108_REG_CONF, &config);
	if (err < 0) {
		dev_err(dev, "error reading config register: %d", err);
		return err;
	}
	tmp108->orig_config = config;

	/* Only continuous mode is supported. */
	config &= ~TMP108_CONF_MODE_MASK;
	config |= TMP108_MODE_CONTINUOUS;

	/* Only comparator mode is supported. */
	config &= ~TMP108_CONF_TM;

	err = regmap_write(tmp108->regmap, TMP108_REG_CONF, config);
	if (err < 0) {
		dev_err(dev, "error writing config register: %d", err);
		return err;
	}

	tmp108->ready_time = jiffies;
	if ((tmp108->orig_config & TMP108_CONF_MODE_MASK) ==
	    TMP108_MODE_SHUTDOWN)
		tmp108->ready_time +=
			msecs_to_jiffies(TMP108_CONVERSION_TIME_MS);

	err = devm_add_action_or_reset(dev, tmp108_restore_config, tmp108);
	if (err) {
		dev_err(dev, "add action or reset failed: %d", err);
		return err;
	}

	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
							 tmp108,
							 &tmp108_chip_info,
							 NULL);
	return PTR_ERR_OR_ZERO(hwmon_dev);
}

static int __maybe_unused tmp108_suspend(struct device *dev)
{
	struct tmp108 *tmp108 = dev_get_drvdata(dev);

	return regmap_update_bits(tmp108->regmap, TMP108_REG_CONF,
				  TMP108_CONF_MODE_MASK, TMP108_MODE_SHUTDOWN);
}

static int __maybe_unused tmp108_resume(struct device *dev)
{
	struct tmp108 *tmp108 = dev_get_drvdata(dev);
	int err;

	err = regmap_update_bits(tmp108->regmap, TMP108_REG_CONF,
				 TMP108_CONF_MODE_MASK, TMP108_MODE_CONTINUOUS);
	tmp108->ready_time = jiffies +
			     msecs_to_jiffies(TMP108_CONVERSION_TIME_MS);
	return err;
}

static SIMPLE_DEV_PM_OPS(tmp108_dev_pm_ops, tmp108_suspend, tmp108_resume);

static const struct i2c_device_id tmp108_i2c_ids[] = {
	{ "tmp108", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, tmp108_i2c_ids);

#ifdef CONFIG_OF
static const struct of_device_id tmp108_of_ids[] = {
	{ .compatible = "ti,tmp108", },
	{}
};
MODULE_DEVICE_TABLE(of, tmp108_of_ids);
#endif

static struct i2c_driver tmp108_driver = {
	.driver = {
		.name	= DRIVER_NAME,
		.pm	= &tmp108_dev_pm_ops,
		.of_match_table = of_match_ptr(tmp108_of_ids),
	},
	.probe		= tmp108_probe,
	.id_table	= tmp108_i2c_ids,
};

module_i2c_driver(tmp108_driver);

MODULE_AUTHOR("John Muir <[email protected]>");
MODULE_DESCRIPTION("Texas Instruments TMP108 temperature sensor driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
66e1c917 JM	1	/* Texas Instruments TMP108 SMBus temperature sensor driver
	2	*
	3	* Copyright (C) 2016 John Muir <[email protected]>
	4	*
	5	* This program is free software; you can redistribute it and/or modify
	6	* it under the terms of the GNU General Public License as published by
	7	* the Free Software Foundation; either version 2 of the License, or
	8	* (at your option) any later version.
	9	*
	10	* This program is distributed in the hope that it will be useful,
	11	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	13	* GNU General Public License for more details.
	14	*/
	15
	16	#include <linux/delay.h>
	17	#include <linux/device.h>
	18	#include <linux/err.h>
	19	#include <linux/hwmon.h>
	20	#include <linux/hwmon-sysfs.h>
	21	#include <linux/module.h>
	22	#include <linux/mutex.h>
	23	#include <linux/of.h>
	24	#include <linux/i2c.h>
	25	#include <linux/init.h>
	26	#include <linux/jiffies.h>
	27	#include <linux/regmap.h>
	28	#include <linux/slab.h>
	29
	30	#define DRIVER_NAME "tmp108"
	31
	32	#define TMP108_REG_TEMP 0x00
	33	#define TMP108_REG_CONF 0x01
	34	#define TMP108_REG_TLOW 0x02
	35	#define TMP108_REG_THIGH 0x03
	36
	37	#define TMP108_TEMP_MIN_MC -50000 /* Minimum millicelcius. */
	38	#define TMP108_TEMP_MAX_MC 127937 /* Maximum millicelcius. */
	39
	40	/* Configuration register bits.
	41	* Note: these bit definitions are byte swapped.
	42	*/
	43	#define TMP108_CONF_M0 0x0100 /* Sensor mode. */
	44	#define TMP108_CONF_M1 0x0200
	45	#define TMP108_CONF_TM 0x0400 /* Thermostat mode. */
	46	#define TMP108_CONF_FL 0x0800 /* Watchdog flag - TLOW */
	47	#define TMP108_CONF_FH 0x1000 /* Watchdog flag - THIGH */
	48	#define TMP108_CONF_CR0 0x2000 /* Conversion rate. */
	49	#define TMP108_CONF_CR1 0x4000
	50	#define TMP108_CONF_ID 0x8000
	51	#define TMP108_CONF_HYS0 0x0010 /* Hysteresis. */
	52	#define TMP108_CONF_HYS1 0x0020
	53	#define TMP108_CONF_POL 0x0080 /* Polarity of alert. */
	54
	55	/* Defaults set by the hardware upon reset. */
	56	#define TMP108_CONF_DEFAULTS (TMP108_CONF_CR0 \| TMP108_CONF_TM \|\
	57	TMP108_CONF_HYS0 \| TMP108_CONF_M1)
	58	/* These bits are read-only. */
	59	#define TMP108_CONF_READ_ONLY (TMP108_CONF_FL \| TMP108_CONF_FH \|\
	60	TMP108_CONF_ID)
	61
	62	#define TMP108_CONF_MODE_MASK (TMP108_CONF_M0\|TMP108_CONF_M1)
	63	#define TMP108_MODE_SHUTDOWN 0x0000
	64	#define TMP108_MODE_ONE_SHOT TMP108_CONF_M0
65	#define TMP108_MODE_CONTINUOUS TMP108_CONF_M1 /* Default */
66	/* When M1 is set, M0 is ignored. */
67
68	#define TMP108_CONF_CONVRATE_MASK (TMP108_CONF_CR0\|TMP108_CONF_CR1)
69	#define TMP108_CONVRATE_0P25HZ 0x0000
70	#define TMP108_CONVRATE_1HZ TMP108_CONF_CR0 /* Default */
71	#define TMP108_CONVRATE_4HZ TMP108_CONF_CR1
72	#define TMP108_CONVRATE_16HZ (TMP108_CONF_CR0\|TMP108_CONF_CR1)
73
74	#define TMP108_CONF_HYSTERESIS_MASK (TMP108_CONF_HYS0\|TMP108_CONF_HYS1)
75	#define TMP108_HYSTERESIS_0C 0x0000
76	#define TMP108_HYSTERESIS_1C TMP108_CONF_HYS0 /* Default */
77	#define TMP108_HYSTERESIS_2C TMP108_CONF_HYS1
78	#define TMP108_HYSTERESIS_4C (TMP108_CONF_HYS0\|TMP108_CONF_HYS1)
79
80	#define TMP108_CONVERSION_TIME_MS 30 /* in milli-seconds */
81
82	struct tmp108 {
83	struct regmap *regmap;
84	u16 orig_config;
85	unsigned long ready_time;
86	};
87
88	/* convert 12-bit TMP108 register value to milliCelsius */
89	static inline int tmp108_temp_reg_to_mC(s16 val)
90	{
91	return (val & ~0x0f) * 1000 / 256;
92	}
93
94	/* convert milliCelsius to left adjusted 12-bit TMP108 register value */
95	static inline u16 tmp108_mC_to_temp_reg(int val)
96	{
97	return (val * 256) / 1000;
98	}
99
100	static int tmp108_read(struct device *dev, enum hwmon_sensor_types type,
101	u32 attr, int channel, long *temp)
102	{
103	struct tmp108 *tmp108 = dev_get_drvdata(dev);
104	unsigned int regval;
105	int err, hyst;
106
107	if (type == hwmon_chip) {
108	if (attr == hwmon_chip_update_interval) {
109	err = regmap_read(tmp108->regmap, TMP108_REG_CONF,
110	&regval);
111	if (err < 0)
112	return err;
113	switch (regval & TMP108_CONF_CONVRATE_MASK) {
114	case TMP108_CONVRATE_0P25HZ:
115	default:
116	*temp = 4000;
117	break;
118	case TMP108_CONVRATE_1HZ:
119	*temp = 1000;
120	break;
121	case TMP108_CONVRATE_4HZ:
122	*temp = 250;
123	break;
124	case TMP108_CONVRATE_16HZ:
125	*temp = 63;
126	break;
127	}
128	return 0;
129	}
130	return -EOPNOTSUPP;
131	}
132
133	switch (attr) {
134	case hwmon_temp_input:
135	/* Is it too early to return a conversion ? */
136	if (time_before(jiffies, tmp108->ready_time)) {
137	dev_dbg(dev, "%s: Conversion not ready yet..\n",
138	__func__);
139	return -EAGAIN;
140	}
141	err = regmap_read(tmp108->regmap, TMP108_REG_TEMP, &regval);
142	if (err < 0)
143	return err;
144	*temp = tmp108_temp_reg_to_mC(regval);
145	break;
146	case hwmon_temp_min:
147	case hwmon_temp_max:
148	err = regmap_read(tmp108->regmap, attr == hwmon_temp_min ?
149	TMP108_REG_TLOW : TMP108_REG_THIGH, &regval);
150	if (err < 0)
151	return err;
152	*temp = tmp108_temp_reg_to_mC(regval);
153	break;
154	case hwmon_temp_min_alarm:
155	case hwmon_temp_max_alarm:
156	err = regmap_read(tmp108->regmap, TMP108_REG_CONF, &regval);
157	if (err < 0)
158	return err;
159	*temp = !!(regval & (attr == hwmon_temp_min_alarm ?
160	TMP108_CONF_FL : TMP108_CONF_FH));
161	break;
162	case hwmon_temp_min_hyst:
163	case hwmon_temp_max_hyst:
164	err = regmap_read(tmp108->regmap, TMP108_REG_CONF, &regval);
165	if (err < 0)
166	return err;
167	switch (regval & TMP108_CONF_HYSTERESIS_MASK) {
168	case TMP108_HYSTERESIS_0C:
169	default:
170	hyst = 0;
171	break;
172	case TMP108_HYSTERESIS_1C:
173	hyst = 1000;
174	break;
175	case TMP108_HYSTERESIS_2C:
176	hyst = 2000;
177	break;
178	case TMP108_HYSTERESIS_4C:
179	hyst = 4000;
180	break;
181	}
182	err = regmap_read(tmp108->regmap, attr == hwmon_temp_min_hyst ?
183	TMP108_REG_TLOW : TMP108_REG_THIGH, &regval);
184	if (err < 0)
185	return err;
186	*temp = tmp108_temp_reg_to_mC(regval);
187	if (attr == hwmon_temp_min_hyst)
188	*temp += hyst;
189	else
190	*temp -= hyst;
191	break;
192	default:
193	return -EOPNOTSUPP;
194	}
195
196	return 0;
197	}
198
199	static int tmp108_write(struct device *dev, enum hwmon_sensor_types type,
200	u32 attr, int channel, long temp)
201	{
202	struct tmp108 *tmp108 = dev_get_drvdata(dev);
203	u32 regval, mask;
204	int err;
205
206	if (type == hwmon_chip) {
207	if (attr == hwmon_chip_update_interval) {
208	if (temp < 156)
209	mask = TMP108_CONVRATE_16HZ;
210	else if (temp < 625)
211	mask = TMP108_CONVRATE_4HZ;
212	else if (temp < 2500)
213	mask = TMP108_CONVRATE_1HZ;
214	else
215	mask = TMP108_CONVRATE_0P25HZ;
216	return regmap_update_bits(tmp108->regmap,
217	TMP108_REG_CONF,
218	TMP108_CONF_CONVRATE_MASK,
219	mask);
220	}
221	return -EOPNOTSUPP;
222	}
223
224	switch (attr) {
225	case hwmon_temp_min:
226	case hwmon_temp_max:
227	temp = clamp_val(temp, TMP108_TEMP_MIN_MC, TMP108_TEMP_MAX_MC);
228	return regmap_write(tmp108->regmap,
229	attr == hwmon_temp_min ?
230	TMP108_REG_TLOW : TMP108_REG_THIGH,
231	tmp108_mC_to_temp_reg(temp));
232	case hwmon_temp_min_hyst:
233	case hwmon_temp_max_hyst:
234	temp = clamp_val(temp, TMP108_TEMP_MIN_MC, TMP108_TEMP_MAX_MC);
235	err = regmap_read(tmp108->regmap,
236	attr == hwmon_temp_min_hyst ?
237	TMP108_REG_TLOW : TMP108_REG_THIGH,
238	&regval);
239	if (err < 0)
240	return err;
241	if (attr == hwmon_temp_min_hyst)
242	temp -= tmp108_temp_reg_to_mC(regval);
243	else
244	temp = tmp108_temp_reg_to_mC(regval) - temp;
245	if (temp < 500)
246	mask = TMP108_HYSTERESIS_0C;
247	else if (temp < 1500)
248	mask = TMP108_HYSTERESIS_1C;
249	else if (temp < 3000)
250	mask = TMP108_HYSTERESIS_2C;
251	else
252	mask = TMP108_HYSTERESIS_4C;
253	return regmap_update_bits(tmp108->regmap, TMP108_REG_CONF,
254	TMP108_CONF_HYSTERESIS_MASK, mask);
255	default:
256	return -EOPNOTSUPP;
257	}
258	}
259
260	static umode_t tmp108_is_visible(const void *data, enum hwmon_sensor_types type,
261	u32 attr, int channel)
262	{
263	if (type == hwmon_chip && attr == hwmon_chip_update_interval)
264	return 0644;
265
266	if (type != hwmon_temp)
267	return 0;
268
269	switch (attr) {
270	case hwmon_temp_input:
271	case hwmon_temp_min_alarm:
272	case hwmon_temp_max_alarm:
273	return 0444;
274	case hwmon_temp_min:
275	case hwmon_temp_max:
276	case hwmon_temp_min_hyst:
277	case hwmon_temp_max_hyst:
278	return 0644;
279	default:
280	return 0;
281	}
282	}
283
284	static u32 tmp108_chip_config[] = {
285	HWMON_C_REGISTER_TZ \| HWMON_C_UPDATE_INTERVAL,
286	0
287	};
288
289	static const struct hwmon_channel_info tmp108_chip = {
290	.type = hwmon_chip,
291	.config = tmp108_chip_config,
292	};
293
294	static u32 tmp108_temp_config[] = {
295	HWMON_T_INPUT \| HWMON_T_MAX \| HWMON_T_MIN \| HWMON_T_MIN_HYST
296	\| HWMON_T_MAX_HYST \| HWMON_T_MIN_ALARM \| HWMON_T_MAX_ALARM,
297	0
298	};
299
300	static const struct hwmon_channel_info tmp108_temp = {
301	.type = hwmon_temp,
302	.config = tmp108_temp_config,
303	};
304
305	static const struct hwmon_channel_info *tmp108_info[] = {
306	&tmp108_chip,
307	&tmp108_temp,
308	NULL
309	};
310
311	static const struct hwmon_ops tmp108_hwmon_ops = {
312	.is_visible = tmp108_is_visible,
313	.read = tmp108_read,
314	.write = tmp108_write,
315	};
316
317	static const struct hwmon_chip_info tmp108_chip_info = {
318	.ops = &tmp108_hwmon_ops,
319	.info = tmp108_info,
320	};
321
322	static void tmp108_restore_config(void *data)
323	{
324	struct tmp108 *tmp108 = data;
325
326	regmap_write(tmp108->regmap, TMP108_REG_CONF, tmp108->orig_config);
327	}
328
329	static bool tmp108_is_writeable_reg(struct device *dev, unsigned int reg)
330	{
331	return reg != TMP108_REG_TEMP;
332	}
333
334	static bool tmp108_is_volatile_reg(struct device *dev, unsigned int reg)
335	{
336	/* Configuration register must be volatile to enable FL and FH. */
337	return reg == TMP108_REG_TEMP \|\| reg == TMP108_REG_CONF;
338	}
339
340	static const struct regmap_config tmp108_regmap_config = {
341	.reg_bits = 8,
342	.val_bits = 16,
343	.max_register = TMP108_REG_THIGH,
344	.writeable_reg = tmp108_is_writeable_reg,
345	.volatile_reg = tmp108_is_volatile_reg,
346	.val_format_endian = REGMAP_ENDIAN_BIG,
347	.cache_type = REGCACHE_RBTREE,
1c96a2f6 DF	348	.use_single_read = true,
1c96a2f6 DF	349	.use_single_write = true,
66e1c917 JM	350	};
	351
	352	static int tmp108_probe(struct i2c_client *client,
	353	const struct i2c_device_id *id)
	354	{
	355	struct device *dev = &client->dev;
	356	struct device *hwmon_dev;
	357	struct tmp108 *tmp108;
	358	int err;
	359	u32 config;
	360
	361	if (!i2c_check_functionality(client->adapter,
	362	I2C_FUNC_SMBUS_WORD_DATA)) {
	363	dev_err(dev,
	364	"adapter doesn't support SMBus word transactions\n");
	365	return -ENODEV;
	366	}
	367
	368	tmp108 = devm_kzalloc(dev, sizeof(*tmp108), GFP_KERNEL);
	369	if (!tmp108)
	370	return -ENOMEM;
	371
	372	dev_set_drvdata(dev, tmp108);
	373
	374	tmp108->regmap = devm_regmap_init_i2c(client, &tmp108_regmap_config);
	375	if (IS_ERR(tmp108->regmap)) {
	376	err = PTR_ERR(tmp108->regmap);
	377	dev_err(dev, "regmap init failed: %d", err);
	378	return err;
	379	}
	380
	381	err = regmap_read(tmp108->regmap, TMP108_REG_CONF, &config);
	382	if (err < 0) {
	383	dev_err(dev, "error reading config register: %d", err);
	384	return err;
	385	}
	386	tmp108->orig_config = config;
	387
	388	/* Only continuous mode is supported. */
	389	config &= ~TMP108_CONF_MODE_MASK;
	390	config \|= TMP108_MODE_CONTINUOUS;
	391
	392	/* Only comparator mode is supported. */
	393	config &= ~TMP108_CONF_TM;
	394
	395	err = regmap_write(tmp108->regmap, TMP108_REG_CONF, config);
	396	if (err < 0) {
	397	dev_err(dev, "error writing config register: %d", err);
	398	return err;
	399	}
	400
	401	tmp108->ready_time = jiffies;
	402	if ((tmp108->orig_config & TMP108_CONF_MODE_MASK) ==
	403	TMP108_MODE_SHUTDOWN)
	404	tmp108->ready_time +=
	405	msecs_to_jiffies(TMP108_CONVERSION_TIME_MS);
	406
	407	err = devm_add_action_or_reset(dev, tmp108_restore_config, tmp108);
	408	if (err) {
	409	dev_err(dev, "add action or reset failed: %d", err);
	410	return err;
	411	}
	412
	413	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
414	tmp108,
415	&tmp108_chip_info,
416	NULL);
417	return PTR_ERR_OR_ZERO(hwmon_dev);
418	}
419
420	static int __maybe_unused tmp108_suspend(struct device *dev)
421	{
422	struct tmp108 *tmp108 = dev_get_drvdata(dev);
423
424	return regmap_update_bits(tmp108->regmap, TMP108_REG_CONF,
425	TMP108_CONF_MODE_MASK, TMP108_MODE_SHUTDOWN);
426	}
427
428	static int __maybe_unused tmp108_resume(struct device *dev)
429	{
430	struct tmp108 *tmp108 = dev_get_drvdata(dev);
431	int err;
432
433	err = regmap_update_bits(tmp108->regmap, TMP108_REG_CONF,
434	TMP108_CONF_MODE_MASK, TMP108_MODE_CONTINUOUS);
435	tmp108->ready_time = jiffies +
436	msecs_to_jiffies(TMP108_CONVERSION_TIME_MS);
437	return err;
438	}
439
440	static SIMPLE_DEV_PM_OPS(tmp108_dev_pm_ops, tmp108_suspend, tmp108_resume);
441
442	static const struct i2c_device_id tmp108_i2c_ids[] = {
443	{ "tmp108", 0 },
444	{ }
445	};
446	MODULE_DEVICE_TABLE(i2c, tmp108_i2c_ids);
447
448	#ifdef CONFIG_OF
449	static const struct of_device_id tmp108_of_ids[] = {
450	{ .compatible = "ti,tmp108", },
451	{}
452	};
453	MODULE_DEVICE_TABLE(of, tmp108_of_ids);
454	#endif
455
456	static struct i2c_driver tmp108_driver = {
457	.driver = {
458	.name = DRIVER_NAME,
459	.pm = &tmp108_dev_pm_ops,
460	.of_match_table = of_match_ptr(tmp108_of_ids),
461	},
462	.probe = tmp108_probe,
463	.id_table = tmp108_i2c_ids,
464	};
465
466	module_i2c_driver(tmp108_driver);
467
468	MODULE_AUTHOR("John Muir <[email protected]>");
469	MODULE_DESCRIPTION("Texas Instruments TMP108 temperature sensor driver");
470	MODULE_LICENSE("GPL");