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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/module.h>
14 #include <linux/init.h>
15 #include <linux/slab.h>
16 #include <linux/jiffies.h>
17 #include <linux/i2c.h>
18 #include <linux/hwmon.h>
19 #include <linux/err.h>
20 #include <linux/mutex.h>
21 #include <linux/of.h>
22 #include <linux/regmap.h>
23 
24 /* Addresses to scan */
25 static const unsigned short normal_i2c[] = {
26 	0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, I2C_CLIENT_END };
27 
28 /* JC42 registers. All registers are 16 bit. */
29 #define JC42_REG_CAP		0x00
30 #define JC42_REG_CONFIG		0x01
31 #define JC42_REG_TEMP_UPPER	0x02
32 #define JC42_REG_TEMP_LOWER	0x03
33 #define JC42_REG_TEMP_CRITICAL	0x04
34 #define JC42_REG_TEMP		0x05
35 #define JC42_REG_MANID		0x06
36 #define JC42_REG_DEVICEID	0x07
37 #define JC42_REG_SMBUS		0x22 /* NXP and Atmel, possibly others? */
38 
39 /* Status bits in temperature register */
40 #define JC42_ALARM_CRIT_BIT	15
41 #define JC42_ALARM_MAX_BIT	14
42 #define JC42_ALARM_MIN_BIT	13
43 
44 /* Configuration register defines */
45 #define JC42_CFG_CRIT_ONLY	(1 << 2)
46 #define JC42_CFG_TCRIT_LOCK	(1 << 6)
47 #define JC42_CFG_EVENT_LOCK	(1 << 7)
48 #define JC42_CFG_SHUTDOWN	(1 << 8)
49 #define JC42_CFG_HYST_SHIFT	9
50 #define JC42_CFG_HYST_MASK	(0x03 << 9)
51 
52 /* Capabilities */
53 #define JC42_CAP_RANGE		(1 << 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 
68 /* SMBUS register */
69 #define SMBUS_STMOUT		BIT(7)  /* SMBus time-out, active low */
70 
71 /* Supported chips */
72 
73 /* Analog Devices */
74 #define ADT7408_DEVID		0x0801
75 #define ADT7408_DEVID_MASK	0xffff
76 
77 /* Atmel */
78 #define AT30TS00_DEVID		0x8201
79 #define AT30TS00_DEVID_MASK	0xffff
80 
81 #define AT30TSE004_DEVID	0x2200
82 #define AT30TSE004_DEVID_MASK	0xffff
83 
84 /* Giantec */
85 #define GT30TS00_DEVID		0x2200
86 #define GT30TS00_DEVID_MASK	0xff00
87 
88 #define GT34TS02_DEVID		0x3300
89 #define GT34TS02_DEVID_MASK	0xff00
90 
91 /* IDT */
92 #define TSE2004_DEVID		0x2200
93 #define TSE2004_DEVID_MASK	0xff00
94 
95 #define TS3000_DEVID		0x2900  /* Also matches TSE2002 */
96 #define TS3000_DEVID_MASK	0xff00
97 
98 #define TS3001_DEVID		0x3000
99 #define TS3001_DEVID_MASK	0xff00
100 
101 /* Maxim */
102 #define MAX6604_DEVID		0x3e00
103 #define MAX6604_DEVID_MASK	0xffff
104 
105 /* Microchip */
106 #define MCP9804_DEVID		0x0200
107 #define MCP9804_DEVID_MASK	0xfffc
108 
109 #define MCP9808_DEVID		0x0400
110 #define MCP9808_DEVID_MASK	0xfffc
111 
112 #define MCP98242_DEVID		0x2000
113 #define MCP98242_DEVID_MASK	0xfffc
114 
115 #define MCP98243_DEVID		0x2100
116 #define MCP98243_DEVID_MASK	0xfffc
117 
118 #define MCP98244_DEVID		0x2200
119 #define MCP98244_DEVID_MASK	0xfffc
120 
121 #define MCP9843_DEVID		0x0000	/* Also matches mcp9805 */
122 #define MCP9843_DEVID_MASK	0xfffe
123 
124 /* NXP */
125 #define SE97_DEVID		0xa200
126 #define SE97_DEVID_MASK		0xfffc
127 
128 #define SE98_DEVID		0xa100
129 #define SE98_DEVID_MASK		0xfffc
130 
131 /* ON Semiconductor */
132 #define CAT6095_DEVID		0x0800	/* Also matches CAT34TS02 */
133 #define CAT6095_DEVID_MASK	0xffe0
134 
135 #define CAT34TS02C_DEVID	0x0a00
136 #define CAT34TS02C_DEVID_MASK	0xfff0
137 
138 #define CAT34TS04_DEVID		0x2200
139 #define CAT34TS04_DEVID_MASK	0xfff0
140 
141 /* ST Microelectronics */
142 #define STTS424_DEVID		0x0101
143 #define STTS424_DEVID_MASK	0xffff
144 
145 #define STTS424E_DEVID		0x0000
146 #define STTS424E_DEVID_MASK	0xfffe
147 
148 #define STTS2002_DEVID		0x0300
149 #define STTS2002_DEVID_MASK	0xffff
150 
151 #define STTS2004_DEVID		0x2201
152 #define STTS2004_DEVID_MASK	0xffff
153 
154 #define STTS3000_DEVID		0x0200
155 #define STTS3000_DEVID_MASK	0xffff
156 
157 static u16 jc42_hysteresis[] = { 0, 1500, 3000, 6000 };
158 
159 struct jc42_chips {
160 	u16 manid;
161 	u16 devid;
162 	u16 devid_mask;
163 };
164 
165 static struct jc42_chips jc42_chips[] = {
166 	{ ADT_MANID, ADT7408_DEVID, ADT7408_DEVID_MASK },
167 	{ ATMEL_MANID, AT30TS00_DEVID, AT30TS00_DEVID_MASK },
168 	{ ATMEL_MANID2, AT30TSE004_DEVID, AT30TSE004_DEVID_MASK },
169 	{ GT_MANID, GT30TS00_DEVID, GT30TS00_DEVID_MASK },
170 	{ GT_MANID2, GT34TS02_DEVID, GT34TS02_DEVID_MASK },
171 	{ IDT_MANID, TSE2004_DEVID, TSE2004_DEVID_MASK },
172 	{ IDT_MANID, TS3000_DEVID, TS3000_DEVID_MASK },
173 	{ IDT_MANID, TS3001_DEVID, TS3001_DEVID_MASK },
174 	{ MAX_MANID, MAX6604_DEVID, MAX6604_DEVID_MASK },
175 	{ MCP_MANID, MCP9804_DEVID, MCP9804_DEVID_MASK },
176 	{ MCP_MANID, MCP9808_DEVID, MCP9808_DEVID_MASK },
177 	{ MCP_MANID, MCP98242_DEVID, MCP98242_DEVID_MASK },
178 	{ MCP_MANID, MCP98243_DEVID, MCP98243_DEVID_MASK },
179 	{ MCP_MANID, MCP98244_DEVID, MCP98244_DEVID_MASK },
180 	{ MCP_MANID, MCP9843_DEVID, MCP9843_DEVID_MASK },
181 	{ NXP_MANID, SE97_DEVID, SE97_DEVID_MASK },
182 	{ ONS_MANID, CAT6095_DEVID, CAT6095_DEVID_MASK },
183 	{ ONS_MANID, CAT34TS02C_DEVID, CAT34TS02C_DEVID_MASK },
184 	{ ONS_MANID, CAT34TS04_DEVID, CAT34TS04_DEVID_MASK },
185 	{ NXP_MANID, SE98_DEVID, SE98_DEVID_MASK },
186 	{ STM_MANID, STTS424_DEVID, STTS424_DEVID_MASK },
187 	{ STM_MANID, STTS424E_DEVID, STTS424E_DEVID_MASK },
188 	{ STM_MANID, STTS2002_DEVID, STTS2002_DEVID_MASK },
189 	{ STM_MANID, STTS2004_DEVID, STTS2004_DEVID_MASK },
190 	{ STM_MANID, STTS3000_DEVID, STTS3000_DEVID_MASK },
191 };
192 
193 /* Each client has this additional data */
194 struct jc42_data {
195 	struct mutex	update_lock;	/* protect register access */
196 	struct regmap	*regmap;
197 	bool		extended;	/* true if extended range supported */
198 	bool		valid;
199 	u16		orig_config;	/* original configuration */
200 	u16		config;		/* current configuration */
201 };
202 
203 #define JC42_TEMP_MIN_EXTENDED	(-40000)
204 #define JC42_TEMP_MIN		0
205 #define JC42_TEMP_MAX		125000
206 
jc42_temp_to_reg(long temp,bool extended)207 static u16 jc42_temp_to_reg(long temp, bool extended)
208 {
209 	int ntemp = clamp_val(temp,
210 			      extended ? JC42_TEMP_MIN_EXTENDED :
211 			      JC42_TEMP_MIN, JC42_TEMP_MAX);
212 
213 	/* convert from 0.001 to 0.0625 resolution */
214 	return (ntemp * 2 / 125) & 0x1fff;
215 }
216 
jc42_temp_from_reg(s16 reg)217 static int jc42_temp_from_reg(s16 reg)
218 {
219 	reg = sign_extend32(reg, 12);
220 
221 	/* convert from 0.0625 to 0.001 resolution */
222 	return reg * 125 / 2;
223 }
224 
jc42_read(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long * val)225 static int jc42_read(struct device *dev, enum hwmon_sensor_types type,
226 		     u32 attr, int channel, long *val)
227 {
228 	struct jc42_data *data = dev_get_drvdata(dev);
229 	unsigned int regval;
230 	int ret, temp, hyst;
231 
232 	mutex_lock(&data->update_lock);
233 
234 	switch (attr) {
235 	case hwmon_temp_input:
236 		ret = regmap_read(data->regmap, JC42_REG_TEMP, &regval);
237 		if (ret)
238 			break;
239 
240 		*val = jc42_temp_from_reg(regval);
241 		break;
242 	case hwmon_temp_min:
243 		ret = regmap_read(data->regmap, JC42_REG_TEMP_LOWER, &regval);
244 		if (ret)
245 			break;
246 
247 		*val = jc42_temp_from_reg(regval);
248 		break;
249 	case hwmon_temp_max:
250 		ret = regmap_read(data->regmap, JC42_REG_TEMP_UPPER, &regval);
251 		if (ret)
252 			break;
253 
254 		*val = jc42_temp_from_reg(regval);
255 		break;
256 	case hwmon_temp_crit:
257 		ret = regmap_read(data->regmap, JC42_REG_TEMP_CRITICAL,
258 				  &regval);
259 		if (ret)
260 			break;
261 
262 		*val = jc42_temp_from_reg(regval);
263 		break;
264 	case hwmon_temp_max_hyst:
265 		ret = regmap_read(data->regmap, JC42_REG_TEMP_UPPER, &regval);
266 		if (ret)
267 			break;
268 
269 		temp = jc42_temp_from_reg(regval);
270 		hyst = jc42_hysteresis[(data->config & JC42_CFG_HYST_MASK)
271 						>> JC42_CFG_HYST_SHIFT];
272 		*val = temp - hyst;
273 		break;
274 	case hwmon_temp_crit_hyst:
275 		ret = regmap_read(data->regmap, JC42_REG_TEMP_CRITICAL,
276 				  &regval);
277 		if (ret)
278 			break;
279 
280 		temp = jc42_temp_from_reg(regval);
281 		hyst = jc42_hysteresis[(data->config & JC42_CFG_HYST_MASK)
282 						>> JC42_CFG_HYST_SHIFT];
283 		*val = temp - hyst;
284 		break;
285 	case hwmon_temp_min_alarm:
286 		ret = regmap_read(data->regmap, JC42_REG_TEMP, &regval);
287 		if (ret)
288 			break;
289 
290 		*val = (regval >> JC42_ALARM_MIN_BIT) & 1;
291 		break;
292 	case hwmon_temp_max_alarm:
293 		ret = regmap_read(data->regmap, JC42_REG_TEMP, &regval);
294 		if (ret)
295 			break;
296 
297 		*val = (regval >> JC42_ALARM_MAX_BIT) & 1;
298 		break;
299 	case hwmon_temp_crit_alarm:
300 		ret = regmap_read(data->regmap, JC42_REG_TEMP, &regval);
301 		if (ret)
302 			break;
303 
304 		*val = (regval >> JC42_ALARM_CRIT_BIT) & 1;
305 		break;
306 	default:
307 		ret = -EOPNOTSUPP;
308 		break;
309 	}
310 
311 	mutex_unlock(&data->update_lock);
312 
313 	return ret;
314 }
315 
jc42_write(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long val)316 static int jc42_write(struct device *dev, enum hwmon_sensor_types type,
317 		      u32 attr, int channel, long val)
318 {
319 	struct jc42_data *data = dev_get_drvdata(dev);
320 	unsigned int regval;
321 	int diff, hyst;
322 	int ret;
323 
324 	mutex_lock(&data->update_lock);
325 
326 	switch (attr) {
327 	case hwmon_temp_min:
328 		ret = regmap_write(data->regmap, JC42_REG_TEMP_LOWER,
329 				   jc42_temp_to_reg(val, data->extended));
330 		break;
331 	case hwmon_temp_max:
332 		ret = regmap_write(data->regmap, JC42_REG_TEMP_UPPER,
333 				   jc42_temp_to_reg(val, data->extended));
334 		break;
335 	case hwmon_temp_crit:
336 		ret = regmap_write(data->regmap, JC42_REG_TEMP_CRITICAL,
337 				   jc42_temp_to_reg(val, data->extended));
338 		break;
339 	case hwmon_temp_crit_hyst:
340 		ret = regmap_read(data->regmap, JC42_REG_TEMP_CRITICAL,
341 				  &regval);
342 		if (ret)
343 			break;
344 
345 		/*
346 		 * JC42.4 compliant chips only support four hysteresis values.
347 		 * Pick best choice and go from there.
348 		 */
349 		val = clamp_val(val, (data->extended ? JC42_TEMP_MIN_EXTENDED
350 						     : JC42_TEMP_MIN) - 6000,
351 				JC42_TEMP_MAX);
352 		diff = jc42_temp_from_reg(regval) - val;
353 		hyst = 0;
354 		if (diff > 0) {
355 			if (diff < 2250)
356 				hyst = 1;	/* 1.5 degrees C */
357 			else if (diff < 4500)
358 				hyst = 2;	/* 3.0 degrees C */
359 			else
360 				hyst = 3;	/* 6.0 degrees C */
361 		}
362 		data->config = (data->config & ~JC42_CFG_HYST_MASK) |
363 				(hyst << JC42_CFG_HYST_SHIFT);
364 		ret = regmap_write(data->regmap, JC42_REG_CONFIG,
365 				   data->config);
366 		break;
367 	default:
368 		ret = -EOPNOTSUPP;
369 		break;
370 	}
371 
372 	mutex_unlock(&data->update_lock);
373 
374 	return ret;
375 }
376 
jc42_is_visible(const void * _data,enum hwmon_sensor_types type,u32 attr,int channel)377 static umode_t jc42_is_visible(const void *_data, enum hwmon_sensor_types type,
378 			       u32 attr, int channel)
379 {
380 	const struct jc42_data *data = _data;
381 	unsigned int config = data->config;
382 	umode_t mode = 0444;
383 
384 	switch (attr) {
385 	case hwmon_temp_min:
386 	case hwmon_temp_max:
387 		if (!(config & JC42_CFG_EVENT_LOCK))
388 			mode |= 0200;
389 		break;
390 	case hwmon_temp_crit:
391 		if (!(config & JC42_CFG_TCRIT_LOCK))
392 			mode |= 0200;
393 		break;
394 	case hwmon_temp_crit_hyst:
395 		if (!(config & (JC42_CFG_EVENT_LOCK | JC42_CFG_TCRIT_LOCK)))
396 			mode |= 0200;
397 		break;
398 	case hwmon_temp_input:
399 	case hwmon_temp_max_hyst:
400 	case hwmon_temp_min_alarm:
401 	case hwmon_temp_max_alarm:
402 	case hwmon_temp_crit_alarm:
403 		break;
404 	default:
405 		mode = 0;
406 		break;
407 	}
408 	return mode;
409 }
410 
411 /* Return 0 if detection is successful, -ENODEV otherwise */
jc42_detect(struct i2c_client * client,struct i2c_board_info * info)412 static int jc42_detect(struct i2c_client *client, struct i2c_board_info *info)
413 {
414 	struct i2c_adapter *adapter = client->adapter;
415 	int i, config, cap, manid, devid;
416 
417 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
418 				     I2C_FUNC_SMBUS_WORD_DATA))
419 		return -ENODEV;
420 
421 	cap = i2c_smbus_read_word_swapped(client, JC42_REG_CAP);
422 	config = i2c_smbus_read_word_swapped(client, JC42_REG_CONFIG);
423 	manid = i2c_smbus_read_word_swapped(client, JC42_REG_MANID);
424 	devid = i2c_smbus_read_word_swapped(client, JC42_REG_DEVICEID);
425 
426 	if (cap < 0 || config < 0 || manid < 0 || devid < 0)
427 		return -ENODEV;
428 
429 	if ((cap & 0xff00) || (config & 0xf800))
430 		return -ENODEV;
431 
432 	for (i = 0; i < ARRAY_SIZE(jc42_chips); i++) {
433 		struct jc42_chips *chip = &jc42_chips[i];
434 		if (manid == chip->manid &&
435 		    (devid & chip->devid_mask) == chip->devid) {
436 			strlcpy(info->type, "jc42", I2C_NAME_SIZE);
437 			return 0;
438 		}
439 	}
440 	return -ENODEV;
441 }
442 
443 static const struct hwmon_channel_info *jc42_info[] = {
444 	HWMON_CHANNEL_INFO(temp,
445 			   HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
446 			   HWMON_T_CRIT | HWMON_T_MAX_HYST |
447 			   HWMON_T_CRIT_HYST | HWMON_T_MIN_ALARM |
448 			   HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM),
449 	NULL
450 };
451 
452 static const struct hwmon_ops jc42_hwmon_ops = {
453 	.is_visible = jc42_is_visible,
454 	.read = jc42_read,
455 	.write = jc42_write,
456 };
457 
458 static const struct hwmon_chip_info jc42_chip_info = {
459 	.ops = &jc42_hwmon_ops,
460 	.info = jc42_info,
461 };
462 
jc42_readable_reg(struct device * dev,unsigned int reg)463 static bool jc42_readable_reg(struct device *dev, unsigned int reg)
464 {
465 	return (reg >= JC42_REG_CAP && reg <= JC42_REG_DEVICEID) ||
466 		reg == JC42_REG_SMBUS;
467 }
468 
jc42_writable_reg(struct device * dev,unsigned int reg)469 static bool jc42_writable_reg(struct device *dev, unsigned int reg)
470 {
471 	return (reg >= JC42_REG_CONFIG && reg <= JC42_REG_TEMP_CRITICAL) ||
472 		reg == JC42_REG_SMBUS;
473 }
474 
jc42_volatile_reg(struct device * dev,unsigned int reg)475 static bool jc42_volatile_reg(struct device *dev, unsigned int reg)
476 {
477 	return reg == JC42_REG_CONFIG || reg == JC42_REG_TEMP;
478 }
479 
480 static const struct regmap_config jc42_regmap_config = {
481 	.reg_bits = 8,
482 	.val_bits = 16,
483 	.val_format_endian = REGMAP_ENDIAN_BIG,
484 	.max_register = JC42_REG_SMBUS,
485 	.writeable_reg = jc42_writable_reg,
486 	.readable_reg = jc42_readable_reg,
487 	.volatile_reg = jc42_volatile_reg,
488 	.cache_type = REGCACHE_RBTREE,
489 };
490 
jc42_probe(struct i2c_client * client)491 static int jc42_probe(struct i2c_client *client)
492 {
493 	struct device *dev = &client->dev;
494 	struct device *hwmon_dev;
495 	unsigned int config, cap;
496 	struct jc42_data *data;
497 	int ret;
498 
499 	data = devm_kzalloc(dev, sizeof(struct jc42_data), GFP_KERNEL);
500 	if (!data)
501 		return -ENOMEM;
502 
503 	data->regmap = devm_regmap_init_i2c(client, &jc42_regmap_config);
504 	if (IS_ERR(data->regmap))
505 		return PTR_ERR(data->regmap);
506 
507 	i2c_set_clientdata(client, data);
508 	mutex_init(&data->update_lock);
509 
510 	ret = regmap_read(data->regmap, JC42_REG_CAP, &cap);
511 	if (ret)
512 		return ret;
513 
514 	data->extended = !!(cap & JC42_CAP_RANGE);
515 
516 	if (device_property_read_bool(dev, "smbus-timeout-disable")) {
517 		/*
518 		 * Not all chips support this register, but from a
519 		 * quick read of various datasheets no chip appears
520 		 * incompatible with the below attempt to disable
521 		 * the timeout. And the whole thing is opt-in...
522 		 */
523 		ret = regmap_set_bits(data->regmap, JC42_REG_SMBUS,
524 				      SMBUS_STMOUT);
525 		if (ret)
526 			return ret;
527 	}
528 
529 	ret = regmap_read(data->regmap, JC42_REG_CONFIG, &config);
530 	if (ret)
531 		return ret;
532 
533 	data->orig_config = config;
534 	if (config & JC42_CFG_SHUTDOWN) {
535 		config &= ~JC42_CFG_SHUTDOWN;
536 		regmap_write(data->regmap, JC42_REG_CONFIG, config);
537 	}
538 	data->config = config;
539 
540 	hwmon_dev = devm_hwmon_device_register_with_info(dev, "jc42",
541 							 data, &jc42_chip_info,
542 							 NULL);
543 	return PTR_ERR_OR_ZERO(hwmon_dev);
544 }
545 
jc42_remove(struct i2c_client * client)546 static int jc42_remove(struct i2c_client *client)
547 {
548 	struct jc42_data *data = i2c_get_clientdata(client);
549 
550 	/* Restore original configuration except hysteresis */
551 	if ((data->config & ~JC42_CFG_HYST_MASK) !=
552 	    (data->orig_config & ~JC42_CFG_HYST_MASK)) {
553 		int config;
554 
555 		config = (data->orig_config & ~JC42_CFG_HYST_MASK)
556 		  | (data->config & JC42_CFG_HYST_MASK);
557 		regmap_write(data->regmap, JC42_REG_CONFIG, config);
558 	}
559 	return 0;
560 }
561 
562 #ifdef CONFIG_PM
563 
jc42_suspend(struct device * dev)564 static int jc42_suspend(struct device *dev)
565 {
566 	struct jc42_data *data = dev_get_drvdata(dev);
567 
568 	data->config |= JC42_CFG_SHUTDOWN;
569 	regmap_write(data->regmap, JC42_REG_CONFIG, data->config);
570 
571 	regcache_cache_only(data->regmap, true);
572 	regcache_mark_dirty(data->regmap);
573 
574 	return 0;
575 }
576 
jc42_resume(struct device * dev)577 static int jc42_resume(struct device *dev)
578 {
579 	struct jc42_data *data = dev_get_drvdata(dev);
580 
581 	regcache_cache_only(data->regmap, false);
582 
583 	data->config &= ~JC42_CFG_SHUTDOWN;
584 	regmap_write(data->regmap, JC42_REG_CONFIG, data->config);
585 
586 	/* Restore cached register values to hardware */
587 	return regcache_sync(data->regmap);
588 }
589 
590 static const struct dev_pm_ops jc42_dev_pm_ops = {
591 	.suspend = jc42_suspend,
592 	.resume = jc42_resume,
593 };
594 
595 #define JC42_DEV_PM_OPS (&jc42_dev_pm_ops)
596 #else
597 #define JC42_DEV_PM_OPS NULL
598 #endif /* CONFIG_PM */
599 
600 static const struct i2c_device_id jc42_id[] = {
601 	{ "jc42", 0 },
602 	{ }
603 };
604 MODULE_DEVICE_TABLE(i2c, jc42_id);
605 
606 #ifdef CONFIG_OF
607 static const struct of_device_id jc42_of_ids[] = {
608 	{ .compatible = "jedec,jc-42.4-temp", },
609 	{ }
610 };
611 MODULE_DEVICE_TABLE(of, jc42_of_ids);
612 #endif
613 
614 static struct i2c_driver jc42_driver = {
615 	.class		= I2C_CLASS_SPD | I2C_CLASS_HWMON,
616 	.driver = {
617 		.name	= "jc42",
618 		.pm = JC42_DEV_PM_OPS,
619 		.of_match_table = of_match_ptr(jc42_of_ids),
620 	},
621 	.probe_new	= jc42_probe,
622 	.remove		= jc42_remove,
623 	.id_table	= jc42_id,
624 	.detect		= jc42_detect,
625 	.address_list	= normal_i2c,
626 };
627 
628 module_i2c_driver(jc42_driver);
629 
630 MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>");
631 MODULE_DESCRIPTION("JC42 driver");
632 MODULE_LICENSE("GPL");
633