1// SPDX-License-Identifier: GPL-2.0-or-later
2/* Texas Instruments TMP102 SMBus temperature sensor driver
3 *
4 * Copyright (C) 2010 Steven King <sfking@fdwdc.com>
5 */
6
7#include <linux/delay.h>
8#include <linux/module.h>
9#include <linux/init.h>
10#include <linux/slab.h>
11#include <linux/i2c.h>
12#include <linux/hwmon.h>
13#include <linux/hwmon-sysfs.h>
14#include <linux/err.h>
15#include <linux/mutex.h>
16#include <linux/device.h>
17#include <linux/jiffies.h>
18#include <linux/regmap.h>
19#include <linux/of.h>
20
21#define	DRIVER_NAME "tmp102"
22
23#define	TMP102_TEMP_REG			0x00
24#define	TMP102_CONF_REG			0x01
25/* note: these bit definitions are byte swapped */
26#define		TMP102_CONF_SD		0x0100
27#define		TMP102_CONF_TM		0x0200
28#define		TMP102_CONF_POL		0x0400
29#define		TMP102_CONF_F0		0x0800
30#define		TMP102_CONF_F1		0x1000
31#define		TMP102_CONF_R0		0x2000
32#define		TMP102_CONF_R1		0x4000
33#define		TMP102_CONF_OS		0x8000
34#define		TMP102_CONF_EM		0x0010
35#define		TMP102_CONF_AL		0x0020
36#define		TMP102_CONF_CR0		0x0040
37#define		TMP102_CONF_CR1		0x0080
38#define	TMP102_TLOW_REG			0x02
39#define	TMP102_THIGH_REG		0x03
40
41#define TMP102_CONFREG_MASK	(TMP102_CONF_SD | TMP102_CONF_TM | \
42				 TMP102_CONF_POL | TMP102_CONF_F0 | \
43				 TMP102_CONF_F1 | TMP102_CONF_OS | \
44				 TMP102_CONF_EM | TMP102_CONF_AL | \
45				 TMP102_CONF_CR0 | TMP102_CONF_CR1)
46
47#define TMP102_CONFIG_CLEAR	(TMP102_CONF_SD | TMP102_CONF_OS | \
48				 TMP102_CONF_CR0)
49#define TMP102_CONFIG_SET	(TMP102_CONF_TM | TMP102_CONF_EM | \
50				 TMP102_CONF_CR1)
51
52#define CONVERSION_TIME_MS		35	/* in milli-seconds */
53
54struct tmp102 {
55	struct regmap *regmap;
56	u16 config_orig;
57	unsigned long ready_time;
58};
59
60/* convert left adjusted 13-bit TMP102 register value to milliCelsius */
61static inline int tmp102_reg_to_mC(s16 val)
62{
63	return ((val & ~0x01) * 1000) / 128;
64}
65
66/* convert milliCelsius to left adjusted 13-bit TMP102 register value */
67static inline u16 tmp102_mC_to_reg(int val)
68{
69	return (val * 128) / 1000;
70}
71
72static int tmp102_read(struct device *dev, enum hwmon_sensor_types type,
73		       u32 attr, int channel, long *temp)
74{
75	struct tmp102 *tmp102 = dev_get_drvdata(dev);
76	unsigned int regval;
77	int err, reg;
78
79	switch (attr) {
80	case hwmon_temp_input:
81		/* Is it too early to return a conversion ? */
82		if (time_before(jiffies, tmp102->ready_time)) {
83			dev_dbg(dev, "%s: Conversion not ready yet..\n", __func__);
84			return -EAGAIN;
85		}
86		reg = TMP102_TEMP_REG;
87		break;
88	case hwmon_temp_max_hyst:
89		reg = TMP102_TLOW_REG;
90		break;
91	case hwmon_temp_max:
92		reg = TMP102_THIGH_REG;
93		break;
94	default:
95		return -EOPNOTSUPP;
96	}
97
98	err = regmap_read(tmp102->regmap, reg, &regval);
99	if (err < 0)
100		return err;
101	*temp = tmp102_reg_to_mC(regval);
102
103	return 0;
104}
105
106static int tmp102_write(struct device *dev, enum hwmon_sensor_types type,
107			u32 attr, int channel, long temp)
108{
109	struct tmp102 *tmp102 = dev_get_drvdata(dev);
110	int reg;
111
112	switch (attr) {
113	case hwmon_temp_max_hyst:
114		reg = TMP102_TLOW_REG;
115		break;
116	case hwmon_temp_max:
117		reg = TMP102_THIGH_REG;
118		break;
119	default:
120		return -EOPNOTSUPP;
121	}
122
123	temp = clamp_val(temp, -256000, 255000);
124	return regmap_write(tmp102->regmap, reg, tmp102_mC_to_reg(temp));
125}
126
127static umode_t tmp102_is_visible(const void *data, enum hwmon_sensor_types type,
128				 u32 attr, int channel)
129{
130	if (type != hwmon_temp)
131		return 0;
132
133	switch (attr) {
134	case hwmon_temp_input:
135		return 0444;
136	case hwmon_temp_max_hyst:
137	case hwmon_temp_max:
138		return 0644;
139	default:
140		return 0;
141	}
142}
143
144static const struct hwmon_channel_info * const tmp102_info[] = {
145	HWMON_CHANNEL_INFO(chip,
146			   HWMON_C_REGISTER_TZ),
147	HWMON_CHANNEL_INFO(temp,
148			   HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST),
149	NULL
150};
151
152static const struct hwmon_ops tmp102_hwmon_ops = {
153	.is_visible = tmp102_is_visible,
154	.read = tmp102_read,
155	.write = tmp102_write,
156};
157
158static const struct hwmon_chip_info tmp102_chip_info = {
159	.ops = &tmp102_hwmon_ops,
160	.info = tmp102_info,
161};
162
163static void tmp102_restore_config(void *data)
164{
165	struct tmp102 *tmp102 = data;
166
167	regmap_write(tmp102->regmap, TMP102_CONF_REG, tmp102->config_orig);
168}
169
170static bool tmp102_is_writeable_reg(struct device *dev, unsigned int reg)
171{
172	return reg != TMP102_TEMP_REG;
173}
174
175static bool tmp102_is_volatile_reg(struct device *dev, unsigned int reg)
176{
177	return reg == TMP102_TEMP_REG;
178}
179
180static const struct regmap_config tmp102_regmap_config = {
181	.reg_bits = 8,
182	.val_bits = 16,
183	.max_register = TMP102_THIGH_REG,
184	.writeable_reg = tmp102_is_writeable_reg,
185	.volatile_reg = tmp102_is_volatile_reg,
186	.val_format_endian = REGMAP_ENDIAN_BIG,
187	.cache_type = REGCACHE_MAPLE,
188	.use_single_read = true,
189	.use_single_write = true,
190};
191
192static int tmp102_probe(struct i2c_client *client)
193{
194	struct device *dev = &client->dev;
195	struct device *hwmon_dev;
196	struct tmp102 *tmp102;
197	unsigned int regval;
198	int err;
199
200	if (!i2c_check_functionality(client->adapter,
201				     I2C_FUNC_SMBUS_WORD_DATA)) {
202		dev_err(dev,
203			"adapter doesn't support SMBus word transactions\n");
204		return -ENODEV;
205	}
206
207	tmp102 = devm_kzalloc(dev, sizeof(*tmp102), GFP_KERNEL);
208	if (!tmp102)
209		return -ENOMEM;
210
211	i2c_set_clientdata(client, tmp102);
212
213	tmp102->regmap = devm_regmap_init_i2c(client, &tmp102_regmap_config);
214	if (IS_ERR(tmp102->regmap))
215		return PTR_ERR(tmp102->regmap);
216
217	err = regmap_read(tmp102->regmap, TMP102_CONF_REG, &regval);
218	if (err < 0) {
219		dev_err(dev, "error reading config register\n");
220		return err;
221	}
222
223	if ((regval & ~TMP102_CONFREG_MASK) !=
224	    (TMP102_CONF_R0 | TMP102_CONF_R1)) {
225		dev_err(dev, "unexpected config register value\n");
226		return -ENODEV;
227	}
228
229	tmp102->config_orig = regval;
230
231	err = devm_add_action_or_reset(dev, tmp102_restore_config, tmp102);
232	if (err)
233		return err;
234
235	regval &= ~TMP102_CONFIG_CLEAR;
236	regval |= TMP102_CONFIG_SET;
237
238	err = regmap_write(tmp102->regmap, TMP102_CONF_REG, regval);
239	if (err < 0) {
240		dev_err(dev, "error writing config register\n");
241		return err;
242	}
243
244	/*
245	 * Mark that we are not ready with data until the first
246	 * conversion is complete
247	 */
248	tmp102->ready_time = jiffies + msecs_to_jiffies(CONVERSION_TIME_MS);
249
250	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
251							 tmp102,
252							 &tmp102_chip_info,
253							 NULL);
254	if (IS_ERR(hwmon_dev)) {
255		dev_dbg(dev, "unable to register hwmon device\n");
256		return PTR_ERR(hwmon_dev);
257	}
258	dev_info(dev, "initialized\n");
259
260	return 0;
261}
262
263static int tmp102_suspend(struct device *dev)
264{
265	struct i2c_client *client = to_i2c_client(dev);
266	struct tmp102 *tmp102 = i2c_get_clientdata(client);
267
268	return regmap_update_bits(tmp102->regmap, TMP102_CONF_REG,
269				  TMP102_CONF_SD, TMP102_CONF_SD);
270}
271
272static int tmp102_resume(struct device *dev)
273{
274	struct i2c_client *client = to_i2c_client(dev);
275	struct tmp102 *tmp102 = i2c_get_clientdata(client);
276	int err;
277
278	err = regmap_update_bits(tmp102->regmap, TMP102_CONF_REG,
279				 TMP102_CONF_SD, 0);
280
281	tmp102->ready_time = jiffies + msecs_to_jiffies(CONVERSION_TIME_MS);
282
283	return err;
284}
285
286static DEFINE_SIMPLE_DEV_PM_OPS(tmp102_dev_pm_ops, tmp102_suspend, tmp102_resume);
287
288static const struct i2c_device_id tmp102_id[] = {
289	{ "tmp102" },
290	{ }
291};
292MODULE_DEVICE_TABLE(i2c, tmp102_id);
293
294static const struct of_device_id __maybe_unused tmp102_of_match[] = {
295	{ .compatible = "ti,tmp102" },
296	{ },
297};
298MODULE_DEVICE_TABLE(of, tmp102_of_match);
299
300static struct i2c_driver tmp102_driver = {
301	.driver.name	= DRIVER_NAME,
302	.driver.of_match_table = of_match_ptr(tmp102_of_match),
303	.driver.pm	= pm_sleep_ptr(&tmp102_dev_pm_ops),
304	.probe		= tmp102_probe,
305	.id_table	= tmp102_id,
306};
307
308module_i2c_driver(tmp102_driver);
309
310MODULE_AUTHOR("Steven King <sfking@fdwdc.com>");
311MODULE_DESCRIPTION("Texas Instruments TMP102 temperature sensor driver");
312MODULE_LICENSE("GPL");
313