1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * jc42.c - driver for Jedec JC42.4 compliant temperature sensors
4  *
5  * Copyright (c) 2010  Ericsson AB.
6  *
7  * Derived from lm77.c by Andras BALI <drewie@freemail.hu>.
8  *
9  * JC42.4 compliant temperature sensors are typically used on memory modules.
10  */
11 
12 #include <linux/bitops.h>
13 #include <linux/bitfield.h>
14 #include <linux/module.h>
15 #include <linux/init.h>
16 #include <linux/slab.h>
17 #include <linux/jiffies.h>
18 #include <linux/i2c.h>
19 #include <linux/hwmon.h>
20 #include <linux/err.h>
21 #include <linux/mutex.h>
22 #include <linux/of.h>
23 #include <linux/regmap.h>
24 
25 /* Addresses to scan */
26 static const unsigned short normal_i2c[] = {
27 	0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, I2C_CLIENT_END };
28 
29 /* JC42 registers. All registers are 16 bit. */
30 #define JC42_REG_CAP		0x00
31 #define JC42_REG_CONFIG		0x01
32 #define JC42_REG_TEMP_UPPER	0x02
33 #define JC42_REG_TEMP_LOWER	0x03
34 #define JC42_REG_TEMP_CRITICAL	0x04
35 #define JC42_REG_TEMP		0x05
36 #define JC42_REG_MANID		0x06
37 #define JC42_REG_DEVICEID	0x07
38 #define JC42_REG_SMBUS		0x22 /* NXP and Atmel, possibly others? */
39 
40 /* Status bits in temperature register */
41 #define JC42_ALARM_CRIT		BIT(15)
42 #define JC42_ALARM_MAX		BIT(14)
43 #define JC42_ALARM_MIN		BIT(13)
44 
45 /* Configuration register defines */
46 #define JC42_CFG_CRIT_ONLY	BIT(2)
47 #define JC42_CFG_TCRIT_LOCK	BIT(6)
48 #define JC42_CFG_EVENT_LOCK	BIT(7)
49 #define JC42_CFG_SHUTDOWN	BIT(8)
50 #define JC42_CFG_HYST_MASK	GENMASK(10, 9)
51 
52 /* Capabilities */
53 #define JC42_CAP_RANGE		BIT(2)
54 
55 /* Manufacturer IDs */
56 #define ADT_MANID		0x11d4  /* Analog Devices */
57 #define ATMEL_MANID		0x001f  /* Atmel */
58 #define ATMEL_MANID2		0x1114	/* Atmel */
59 #define MAX_MANID		0x004d  /* Maxim */
60 #define IDT_MANID		0x00b3  /* IDT */
61 #define MCP_MANID		0x0054  /* Microchip */
62 #define NXP_MANID		0x1131  /* NXP Semiconductors */
63 #define ONS_MANID		0x1b09  /* ON Semiconductor */
64 #define STM_MANID		0x104a  /* ST Microelectronics */
65 #define GT_MANID		0x1c68	/* Giantec */
66 #define GT_MANID2		0x132d	/* Giantec, 2nd mfg ID */
67 #define SI_MANID		0x1c85	/* Seiko Instruments */
68 
69 /* SMBUS register */
70 #define SMBUS_STMOUT		BIT(7)  /* SMBus time-out, active low */
71 
72 /* Supported chips */
73 
74 /* Analog Devices */
75 #define ADT7408_DEVID		0x0801
76 #define ADT7408_DEVID_MASK	0xffff
77 
78 /* Atmel */
79 #define AT30TS00_DEVID		0x8201
80 #define AT30TS00_DEVID_MASK	0xffff
81 
82 #define GT34TS02_DEVID		0x3300
83 #define GT34TS02_DEVID_MASK	0xff00
84 
85 #define TS3000_DEVID		0x2900  /* Also matches TSE2002 */
86 #define TS3000_DEVID_MASK	0xff00
87 
88 #define TS3001_DEVID		0x3000
89 #define TS3001_DEVID_MASK	0xff00
90 
91 /* Maxim */
92 #define MAX6604_DEVID		0x3e00
93 #define MAX6604_DEVID_MASK	0xffff
94 
95 /* Microchip */
96 #define MCP9804_DEVID		0x0200
97 #define MCP9804_DEVID_MASK	0xfffc
98 
99 #define MCP9808_DEVID		0x0400
100 #define MCP9808_DEVID_MASK	0xfffc
101 
102 #define MCP98242_DEVID		0x2000
103 #define MCP98242_DEVID_MASK	0xfffc
104 
105 #define MCP98243_DEVID		0x2100
106 #define MCP98243_DEVID_MASK	0xfffc
107 
108 #define MCP9843_DEVID		0x0000	/* Also matches mcp9805 */
109 #define MCP9843_DEVID_MASK	0xfffe
110 
111 /* NXP */
112 #define SE97_DEVID		0xa200
113 #define SE97_DEVID_MASK		0xfffc
114 
115 #define SE98_DEVID		0xa100
116 #define SE98_DEVID_MASK		0xfffc
117 
118 /* ON Semiconductor */
119 #define CAT6095_DEVID		0x0800	/* Also matches CAT34TS02 */
120 #define CAT6095_DEVID_MASK	0xffe0
121 
122 #define CAT34TS02C_DEVID	0x0a00
123 #define CAT34TS02C_DEVID_MASK	0xfff0
124 
125 /* ST Microelectronics */
126 #define STTS424_DEVID		0x0101
127 #define STTS424_DEVID_MASK	0xffff
128 
129 #define STTS424E_DEVID		0x0000
130 #define STTS424E_DEVID_MASK	0xfffe
131 
132 #define STTS2002_DEVID		0x0300
133 #define STTS2002_DEVID_MASK	0xffff
134 
135 #define STTS3000_DEVID		0x0200
136 #define STTS3000_DEVID_MASK	0xffff
137 
138 /* TSE2004 compliant sensors */
139 #define TSE2004_DEVID		0x2200
140 #define TSE2004_DEVID_MASK	0xff00
141 
142 static u16 jc42_hysteresis[] = { 0, 1500, 3000, 6000 };
143 
144 struct jc42_chips {
145 	u16 manid;
146 	u16 devid;
147 	u16 devid_mask;
148 };
149 
150 static struct jc42_chips jc42_chips[] = {
151 	{ ADT_MANID, ADT7408_DEVID, ADT7408_DEVID_MASK },
152 	{ ATMEL_MANID, AT30TS00_DEVID, AT30TS00_DEVID_MASK },
153 	{ ATMEL_MANID2, TSE2004_DEVID, TSE2004_DEVID_MASK },
154 	{ GT_MANID, TSE2004_DEVID, TSE2004_DEVID_MASK },
155 	{ GT_MANID2, GT34TS02_DEVID, GT34TS02_DEVID_MASK },
156 	{ IDT_MANID, TSE2004_DEVID, TSE2004_DEVID_MASK },
157 	{ IDT_MANID, TS3000_DEVID, TS3000_DEVID_MASK },
158 	{ IDT_MANID, TS3001_DEVID, TS3001_DEVID_MASK },
159 	{ MAX_MANID, MAX6604_DEVID, MAX6604_DEVID_MASK },
160 	{ MCP_MANID, MCP9804_DEVID, MCP9804_DEVID_MASK },
161 	{ MCP_MANID, MCP9808_DEVID, MCP9808_DEVID_MASK },
162 	{ MCP_MANID, MCP98242_DEVID, MCP98242_DEVID_MASK },
163 	{ MCP_MANID, MCP98243_DEVID, MCP98243_DEVID_MASK },
164 	{ MCP_MANID, TSE2004_DEVID, TSE2004_DEVID_MASK },
165 	{ MCP_MANID, MCP9843_DEVID, MCP9843_DEVID_MASK },
166 	{ NXP_MANID, SE97_DEVID, SE97_DEVID_MASK },
167 	{ ONS_MANID, CAT6095_DEVID, CAT6095_DEVID_MASK },
168 	{ ONS_MANID, CAT34TS02C_DEVID, CAT34TS02C_DEVID_MASK },
169 	{ ONS_MANID, TSE2004_DEVID, TSE2004_DEVID_MASK },
170 	{ ONS_MANID, TSE2004_DEVID, TSE2004_DEVID_MASK },
171 	{ NXP_MANID, SE98_DEVID, SE98_DEVID_MASK },
172 	{ SI_MANID,  TSE2004_DEVID, TSE2004_DEVID_MASK },
173 	{ STM_MANID, STTS424_DEVID, STTS424_DEVID_MASK },
174 	{ STM_MANID, STTS424E_DEVID, STTS424E_DEVID_MASK },
175 	{ STM_MANID, STTS2002_DEVID, STTS2002_DEVID_MASK },
176 	{ STM_MANID, TSE2004_DEVID, TSE2004_DEVID_MASK },
177 	{ STM_MANID, STTS3000_DEVID, STTS3000_DEVID_MASK },
178 };
179 
180 /* Each client has this additional data */
181 struct jc42_data {
182 	struct mutex	update_lock;	/* protect register access */
183 	struct regmap	*regmap;
184 	bool		extended;	/* true if extended range supported */
185 	bool		valid;
186 	u16		orig_config;	/* original configuration */
187 	u16		config;		/* current configuration */
188 };
189 
190 #define JC42_TEMP_MIN_EXTENDED	(-40000)
191 #define JC42_TEMP_MIN		0
192 #define JC42_TEMP_MAX		125000
193 
jc42_temp_to_reg(long temp,bool extended)194 static u16 jc42_temp_to_reg(long temp, bool extended)
195 {
196 	int ntemp = clamp_val(temp,
197 			      extended ? JC42_TEMP_MIN_EXTENDED :
198 			      JC42_TEMP_MIN, JC42_TEMP_MAX);
199 
200 	/* convert from 0.001 to 0.0625 resolution */
201 	return (ntemp * 2 / 125) & 0x1fff;
202 }
203 
jc42_temp_from_reg(s16 reg)204 static int jc42_temp_from_reg(s16 reg)
205 {
206 	reg = sign_extend32(reg, 12);
207 
208 	/* convert from 0.0625 to 0.001 resolution */
209 	return reg * 125 / 2;
210 }
211 
jc42_read(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long * val)212 static int jc42_read(struct device *dev, enum hwmon_sensor_types type,
213 		     u32 attr, int channel, long *val)
214 {
215 	struct jc42_data *data = dev_get_drvdata(dev);
216 	unsigned int regval;
217 	int ret, temp, hyst;
218 
219 	mutex_lock(&data->update_lock);
220 
221 	switch (attr) {
222 	case hwmon_temp_input:
223 		ret = regmap_read(data->regmap, JC42_REG_TEMP, &regval);
224 		if (ret)
225 			break;
226 
227 		*val = jc42_temp_from_reg(regval);
228 		break;
229 	case hwmon_temp_min:
230 		ret = regmap_read(data->regmap, JC42_REG_TEMP_LOWER, &regval);
231 		if (ret)
232 			break;
233 
234 		*val = jc42_temp_from_reg(regval);
235 		break;
236 	case hwmon_temp_max:
237 		ret = regmap_read(data->regmap, JC42_REG_TEMP_UPPER, &regval);
238 		if (ret)
239 			break;
240 
241 		*val = jc42_temp_from_reg(regval);
242 		break;
243 	case hwmon_temp_crit:
244 		ret = regmap_read(data->regmap, JC42_REG_TEMP_CRITICAL,
245 				  &regval);
246 		if (ret)
247 			break;
248 
249 		*val = jc42_temp_from_reg(regval);
250 		break;
251 	case hwmon_temp_max_hyst:
252 		ret = regmap_read(data->regmap, JC42_REG_TEMP_UPPER, &regval);
253 		if (ret)
254 			break;
255 
256 		temp = jc42_temp_from_reg(regval);
257 		hyst = jc42_hysteresis[FIELD_GET(JC42_CFG_HYST_MASK,
258 						 data->config)];
259 		*val = temp - hyst;
260 		break;
261 	case hwmon_temp_crit_hyst:
262 		ret = regmap_read(data->regmap, JC42_REG_TEMP_CRITICAL,
263 				  &regval);
264 		if (ret)
265 			break;
266 
267 		temp = jc42_temp_from_reg(regval);
268 		hyst = jc42_hysteresis[FIELD_GET(JC42_CFG_HYST_MASK,
269 						 data->config)];
270 		*val = temp - hyst;
271 		break;
272 	case hwmon_temp_min_alarm:
273 		ret = regmap_read(data->regmap, JC42_REG_TEMP, &regval);
274 		if (ret)
275 			break;
276 
277 		*val = FIELD_GET(JC42_ALARM_MIN, regval);
278 		break;
279 	case hwmon_temp_max_alarm:
280 		ret = regmap_read(data->regmap, JC42_REG_TEMP, &regval);
281 		if (ret)
282 			break;
283 
284 		*val = FIELD_GET(JC42_ALARM_MAX, regval);
285 		break;
286 	case hwmon_temp_crit_alarm:
287 		ret = regmap_read(data->regmap, JC42_REG_TEMP, &regval);
288 		if (ret)
289 			break;
290 
291 		*val = FIELD_GET(JC42_ALARM_CRIT, regval);
292 		break;
293 	default:
294 		ret = -EOPNOTSUPP;
295 		break;
296 	}
297 
298 	mutex_unlock(&data->update_lock);
299 
300 	return ret;
301 }
302 
jc42_write(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long val)303 static int jc42_write(struct device *dev, enum hwmon_sensor_types type,
304 		      u32 attr, int channel, long val)
305 {
306 	struct jc42_data *data = dev_get_drvdata(dev);
307 	unsigned int regval;
308 	int diff, hyst;
309 	int ret;
310 
311 	mutex_lock(&data->update_lock);
312 
313 	switch (attr) {
314 	case hwmon_temp_min:
315 		ret = regmap_write(data->regmap, JC42_REG_TEMP_LOWER,
316 				   jc42_temp_to_reg(val, data->extended));
317 		break;
318 	case hwmon_temp_max:
319 		ret = regmap_write(data->regmap, JC42_REG_TEMP_UPPER,
320 				   jc42_temp_to_reg(val, data->extended));
321 		break;
322 	case hwmon_temp_crit:
323 		ret = regmap_write(data->regmap, JC42_REG_TEMP_CRITICAL,
324 				   jc42_temp_to_reg(val, data->extended));
325 		break;
326 	case hwmon_temp_crit_hyst:
327 		ret = regmap_read(data->regmap, JC42_REG_TEMP_CRITICAL,
328 				  &regval);
329 		if (ret)
330 			break;
331 
332 		/*
333 		 * JC42.4 compliant chips only support four hysteresis values.
334 		 * Pick best choice and go from there.
335 		 */
336 		val = clamp_val(val, (data->extended ? JC42_TEMP_MIN_EXTENDED
337 						     : JC42_TEMP_MIN) - 6000,
338 				JC42_TEMP_MAX);
339 		diff = jc42_temp_from_reg(regval) - val;
340 		hyst = 0;
341 		if (diff > 0) {
342 			if (diff < 2250)
343 				hyst = 1;	/* 1.5 degrees C */
344 			else if (diff < 4500)
345 				hyst = 2;	/* 3.0 degrees C */
346 			else
347 				hyst = 3;	/* 6.0 degrees C */
348 		}
349 		data->config = (data->config & ~JC42_CFG_HYST_MASK) |
350 				FIELD_PREP(JC42_CFG_HYST_MASK, hyst);
351 		ret = regmap_write(data->regmap, JC42_REG_CONFIG,
352 				   data->config);
353 		break;
354 	default:
355 		ret = -EOPNOTSUPP;
356 		break;
357 	}
358 
359 	mutex_unlock(&data->update_lock);
360 
361 	return ret;
362 }
363 
jc42_is_visible(const void * _data,enum hwmon_sensor_types type,u32 attr,int channel)364 static umode_t jc42_is_visible(const void *_data, enum hwmon_sensor_types type,
365 			       u32 attr, int channel)
366 {
367 	const struct jc42_data *data = _data;
368 	unsigned int config = data->config;
369 	umode_t mode = 0444;
370 
371 	switch (attr) {
372 	case hwmon_temp_min:
373 	case hwmon_temp_max:
374 		if (!(config & JC42_CFG_EVENT_LOCK))
375 			mode |= 0200;
376 		break;
377 	case hwmon_temp_crit:
378 		if (!(config & JC42_CFG_TCRIT_LOCK))
379 			mode |= 0200;
380 		break;
381 	case hwmon_temp_crit_hyst:
382 		if (!(config & (JC42_CFG_EVENT_LOCK | JC42_CFG_TCRIT_LOCK)))
383 			mode |= 0200;
384 		break;
385 	case hwmon_temp_input:
386 	case hwmon_temp_max_hyst:
387 	case hwmon_temp_min_alarm:
388 	case hwmon_temp_max_alarm:
389 	case hwmon_temp_crit_alarm:
390 		break;
391 	default:
392 		mode = 0;
393 		break;
394 	}
395 	return mode;
396 }
397 
398 /* Return 0 if detection is successful, -ENODEV otherwise */
jc42_detect(struct i2c_client * client,struct i2c_board_info * info)399 static int jc42_detect(struct i2c_client *client, struct i2c_board_info *info)
400 {
401 	struct i2c_adapter *adapter = client->adapter;
402 	int i, config, cap, manid, devid;
403 
404 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
405 				     I2C_FUNC_SMBUS_WORD_DATA))
406 		return -ENODEV;
407 
408 	cap = i2c_smbus_read_word_swapped(client, JC42_REG_CAP);
409 	config = i2c_smbus_read_word_swapped(client, JC42_REG_CONFIG);
410 	manid = i2c_smbus_read_word_swapped(client, JC42_REG_MANID);
411 	devid = i2c_smbus_read_word_swapped(client, JC42_REG_DEVICEID);
412 
413 	if (cap < 0 || config < 0 || manid < 0 || devid < 0)
414 		return -ENODEV;
415 
416 	if ((cap & 0xff00) || (config & 0xf820))
417 		return -ENODEV;
418 
419 	if ((devid & TSE2004_DEVID_MASK) == TSE2004_DEVID &&
420 	    (cap & 0x0062) != 0x0062)
421 		return -ENODEV;
422 
423 	for (i = 0; i < ARRAY_SIZE(jc42_chips); i++) {
424 		struct jc42_chips *chip = &jc42_chips[i];
425 		if (manid == chip->manid &&
426 		    (devid & chip->devid_mask) == chip->devid) {
427 			strscpy(info->type, "jc42", I2C_NAME_SIZE);
428 			return 0;
429 		}
430 	}
431 	return -ENODEV;
432 }
433 
434 static const struct hwmon_channel_info * const jc42_info[] = {
435 	HWMON_CHANNEL_INFO(chip,
436 			   HWMON_C_REGISTER_TZ | HWMON_C_UPDATE_INTERVAL),
437 	HWMON_CHANNEL_INFO(temp,
438 			   HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
439 			   HWMON_T_CRIT | HWMON_T_MAX_HYST |
440 			   HWMON_T_CRIT_HYST | HWMON_T_MIN_ALARM |
441 			   HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM),
442 	NULL
443 };
444 
445 static const struct hwmon_ops jc42_hwmon_ops = {
446 	.is_visible = jc42_is_visible,
447 	.read = jc42_read,
448 	.write = jc42_write,
449 };
450 
451 static const struct hwmon_chip_info jc42_chip_info = {
452 	.ops = &jc42_hwmon_ops,
453 	.info = jc42_info,
454 };
455 
jc42_readable_reg(struct device * dev,unsigned int reg)456 static bool jc42_readable_reg(struct device *dev, unsigned int reg)
457 {
458 	return (reg >= JC42_REG_CAP && reg <= JC42_REG_DEVICEID) ||
459 		reg == JC42_REG_SMBUS;
460 }
461 
jc42_writable_reg(struct device * dev,unsigned int reg)462 static bool jc42_writable_reg(struct device *dev, unsigned int reg)
463 {
464 	return (reg >= JC42_REG_CONFIG && reg <= JC42_REG_TEMP_CRITICAL) ||
465 		reg == JC42_REG_SMBUS;
466 }
467 
jc42_volatile_reg(struct device * dev,unsigned int reg)468 static bool jc42_volatile_reg(struct device *dev, unsigned int reg)
469 {
470 	return reg == JC42_REG_CONFIG || reg == JC42_REG_TEMP;
471 }
472 
473 static const struct regmap_config jc42_regmap_config = {
474 	.reg_bits = 8,
475 	.val_bits = 16,
476 	.val_format_endian = REGMAP_ENDIAN_BIG,
477 	.max_register = JC42_REG_SMBUS,
478 	.writeable_reg = jc42_writable_reg,
479 	.readable_reg = jc42_readable_reg,
480 	.volatile_reg = jc42_volatile_reg,
481 	.cache_type = REGCACHE_MAPLE,
482 };
483 
jc42_probe(struct i2c_client * client)484 static int jc42_probe(struct i2c_client *client)
485 {
486 	struct device *dev = &client->dev;
487 	struct device *hwmon_dev;
488 	unsigned int config, cap;
489 	struct jc42_data *data;
490 	int ret;
491 
492 	data = devm_kzalloc(dev, sizeof(struct jc42_data), GFP_KERNEL);
493 	if (!data)
494 		return -ENOMEM;
495 
496 	data->regmap = devm_regmap_init_i2c(client, &jc42_regmap_config);
497 	if (IS_ERR(data->regmap))
498 		return PTR_ERR(data->regmap);
499 
500 	i2c_set_clientdata(client, data);
501 	mutex_init(&data->update_lock);
502 
503 	ret = regmap_read(data->regmap, JC42_REG_CAP, &cap);
504 	if (ret)
505 		return ret;
506 
507 	data->extended = !!(cap & JC42_CAP_RANGE);
508 
509 	if (device_property_read_bool(dev, "smbus-timeout-disable")) {
510 		/*
511 		 * Not all chips support this register, but from a
512 		 * quick read of various datasheets no chip appears
513 		 * incompatible with the below attempt to disable
514 		 * the timeout. And the whole thing is opt-in...
515 		 */
516 		ret = regmap_set_bits(data->regmap, JC42_REG_SMBUS,
517 				      SMBUS_STMOUT);
518 		if (ret)
519 			return ret;
520 	}
521 
522 	ret = regmap_read(data->regmap, JC42_REG_CONFIG, &config);
523 	if (ret)
524 		return ret;
525 
526 	data->orig_config = config;
527 	if (config & JC42_CFG_SHUTDOWN) {
528 		config &= ~JC42_CFG_SHUTDOWN;
529 		regmap_write(data->regmap, JC42_REG_CONFIG, config);
530 	}
531 	data->config = config;
532 
533 	hwmon_dev = devm_hwmon_device_register_with_info(dev, "jc42",
534 							 data, &jc42_chip_info,
535 							 NULL);
536 	return PTR_ERR_OR_ZERO(hwmon_dev);
537 }
538 
jc42_remove(struct i2c_client * client)539 static void jc42_remove(struct i2c_client *client)
540 {
541 	struct jc42_data *data = i2c_get_clientdata(client);
542 
543 	/* Restore original configuration except hysteresis */
544 	if ((data->config & ~JC42_CFG_HYST_MASK) !=
545 	    (data->orig_config & ~JC42_CFG_HYST_MASK)) {
546 		int config;
547 
548 		config = (data->orig_config & ~JC42_CFG_HYST_MASK)
549 		  | (data->config & JC42_CFG_HYST_MASK);
550 		regmap_write(data->regmap, JC42_REG_CONFIG, config);
551 	}
552 }
553 
554 #ifdef CONFIG_PM
555 
jc42_suspend(struct device * dev)556 static int jc42_suspend(struct device *dev)
557 {
558 	struct jc42_data *data = dev_get_drvdata(dev);
559 
560 	data->config |= JC42_CFG_SHUTDOWN;
561 	regmap_write(data->regmap, JC42_REG_CONFIG, data->config);
562 
563 	regcache_cache_only(data->regmap, true);
564 	regcache_mark_dirty(data->regmap);
565 
566 	return 0;
567 }
568 
jc42_resume(struct device * dev)569 static int jc42_resume(struct device *dev)
570 {
571 	struct jc42_data *data = dev_get_drvdata(dev);
572 
573 	regcache_cache_only(data->regmap, false);
574 
575 	data->config &= ~JC42_CFG_SHUTDOWN;
576 	regmap_write(data->regmap, JC42_REG_CONFIG, data->config);
577 
578 	/* Restore cached register values to hardware */
579 	return regcache_sync(data->regmap);
580 }
581 
582 static const struct dev_pm_ops jc42_dev_pm_ops = {
583 	.suspend = jc42_suspend,
584 	.resume = jc42_resume,
585 };
586 
587 #define JC42_DEV_PM_OPS (&jc42_dev_pm_ops)
588 #else
589 #define JC42_DEV_PM_OPS NULL
590 #endif /* CONFIG_PM */
591 
592 static const struct i2c_device_id jc42_id[] = {
593 	{ "jc42" },
594 	{ }
595 };
596 MODULE_DEVICE_TABLE(i2c, jc42_id);
597 
598 #ifdef CONFIG_OF
599 static const struct of_device_id jc42_of_ids[] = {
600 	{ .compatible = "jedec,jc-42.4-temp", },
601 	{ }
602 };
603 MODULE_DEVICE_TABLE(of, jc42_of_ids);
604 #endif
605 
606 static struct i2c_driver jc42_driver = {
607 	.class		= I2C_CLASS_HWMON,
608 	.driver = {
609 		.name	= "jc42",
610 		.pm = JC42_DEV_PM_OPS,
611 		.of_match_table = of_match_ptr(jc42_of_ids),
612 	},
613 	.probe		= jc42_probe,
614 	.remove		= jc42_remove,
615 	.id_table	= jc42_id,
616 	.detect		= jc42_detect,
617 	.address_list	= normal_i2c,
618 };
619 
620 module_i2c_driver(jc42_driver);
621 
622 MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>");
623 MODULE_DESCRIPTION("JC42 driver");
624 MODULE_LICENSE("GPL");
625