1 /*
2  * jc42.c - driver for Jedec JC42.4 compliant temperature sensors
3  *
4  * Copyright (c) 2010  Ericsson AB.
5  *
6  * Derived from lm77.c by Andras BALI <drewie@freemail.hu>.
7  *
8  * JC42.4 compliant temperature sensors are typically used on memory modules.
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License as published by
12  * the Free Software Foundation; either version 2 of the License, or
13  * (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  * GNU General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software
22  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
23  */
24 
25 #include <linux/bitops.h>
26 #include <linux/module.h>
27 #include <linux/init.h>
28 #include <linux/slab.h>
29 #include <linux/jiffies.h>
30 #include <linux/i2c.h>
31 #include <linux/hwmon.h>
32 #include <linux/err.h>
33 #include <linux/mutex.h>
34 #include <linux/of.h>
35 
36 /* Addresses to scan */
37 static const unsigned short normal_i2c[] = {
38 	0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, I2C_CLIENT_END };
39 
40 /* JC42 registers. All registers are 16 bit. */
41 #define JC42_REG_CAP		0x00
42 #define JC42_REG_CONFIG		0x01
43 #define JC42_REG_TEMP_UPPER	0x02
44 #define JC42_REG_TEMP_LOWER	0x03
45 #define JC42_REG_TEMP_CRITICAL	0x04
46 #define JC42_REG_TEMP		0x05
47 #define JC42_REG_MANID		0x06
48 #define JC42_REG_DEVICEID	0x07
49 #define JC42_REG_SMBUS		0x22 /* NXP and Atmel, possibly others? */
50 
51 /* Status bits in temperature register */
52 #define JC42_ALARM_CRIT_BIT	15
53 #define JC42_ALARM_MAX_BIT	14
54 #define JC42_ALARM_MIN_BIT	13
55 
56 /* Configuration register defines */
57 #define JC42_CFG_CRIT_ONLY	(1 << 2)
58 #define JC42_CFG_TCRIT_LOCK	(1 << 6)
59 #define JC42_CFG_EVENT_LOCK	(1 << 7)
60 #define JC42_CFG_SHUTDOWN	(1 << 8)
61 #define JC42_CFG_HYST_SHIFT	9
62 #define JC42_CFG_HYST_MASK	(0x03 << 9)
63 
64 /* Capabilities */
65 #define JC42_CAP_RANGE		(1 << 2)
66 
67 /* Manufacturer IDs */
68 #define ADT_MANID		0x11d4  /* Analog Devices */
69 #define ATMEL_MANID		0x001f  /* Atmel */
70 #define ATMEL_MANID2		0x1114	/* Atmel */
71 #define MAX_MANID		0x004d  /* Maxim */
72 #define IDT_MANID		0x00b3  /* IDT */
73 #define MCP_MANID		0x0054  /* Microchip */
74 #define NXP_MANID		0x1131  /* NXP Semiconductors */
75 #define ONS_MANID		0x1b09  /* ON Semiconductor */
76 #define STM_MANID		0x104a  /* ST Microelectronics */
77 #define GT_MANID		0x1c68	/* Giantec */
78 #define GT_MANID2		0x132d	/* Giantec, 2nd mfg ID */
79 
80 /* SMBUS register */
81 #define SMBUS_STMOUT		BIT(7)  /* SMBus time-out, active low */
82 
83 /* Supported chips */
84 
85 /* Analog Devices */
86 #define ADT7408_DEVID		0x0801
87 #define ADT7408_DEVID_MASK	0xffff
88 
89 /* Atmel */
90 #define AT30TS00_DEVID		0x8201
91 #define AT30TS00_DEVID_MASK	0xffff
92 
93 #define AT30TSE004_DEVID	0x2200
94 #define AT30TSE004_DEVID_MASK	0xffff
95 
96 /* Giantec */
97 #define GT30TS00_DEVID		0x2200
98 #define GT30TS00_DEVID_MASK	0xff00
99 
100 #define GT34TS02_DEVID		0x3300
101 #define GT34TS02_DEVID_MASK	0xff00
102 
103 /* IDT */
104 #define TSE2004_DEVID		0x2200
105 #define TSE2004_DEVID_MASK	0xff00
106 
107 #define TS3000_DEVID		0x2900  /* Also matches TSE2002 */
108 #define TS3000_DEVID_MASK	0xff00
109 
110 #define TS3001_DEVID		0x3000
111 #define TS3001_DEVID_MASK	0xff00
112 
113 /* Maxim */
114 #define MAX6604_DEVID		0x3e00
115 #define MAX6604_DEVID_MASK	0xffff
116 
117 /* Microchip */
118 #define MCP9804_DEVID		0x0200
119 #define MCP9804_DEVID_MASK	0xfffc
120 
121 #define MCP9808_DEVID		0x0400
122 #define MCP9808_DEVID_MASK	0xfffc
123 
124 #define MCP98242_DEVID		0x2000
125 #define MCP98242_DEVID_MASK	0xfffc
126 
127 #define MCP98243_DEVID		0x2100
128 #define MCP98243_DEVID_MASK	0xfffc
129 
130 #define MCP98244_DEVID		0x2200
131 #define MCP98244_DEVID_MASK	0xfffc
132 
133 #define MCP9843_DEVID		0x0000	/* Also matches mcp9805 */
134 #define MCP9843_DEVID_MASK	0xfffe
135 
136 /* NXP */
137 #define SE97_DEVID		0xa200
138 #define SE97_DEVID_MASK		0xfffc
139 
140 #define SE98_DEVID		0xa100
141 #define SE98_DEVID_MASK		0xfffc
142 
143 /* ON Semiconductor */
144 #define CAT6095_DEVID		0x0800	/* Also matches CAT34TS02 */
145 #define CAT6095_DEVID_MASK	0xffe0
146 
147 #define CAT34TS02C_DEVID	0x0a00
148 #define CAT34TS02C_DEVID_MASK	0xfff0
149 
150 #define CAT34TS04_DEVID		0x2200
151 #define CAT34TS04_DEVID_MASK	0xfff0
152 
153 /* ST Microelectronics */
154 #define STTS424_DEVID		0x0101
155 #define STTS424_DEVID_MASK	0xffff
156 
157 #define STTS424E_DEVID		0x0000
158 #define STTS424E_DEVID_MASK	0xfffe
159 
160 #define STTS2002_DEVID		0x0300
161 #define STTS2002_DEVID_MASK	0xffff
162 
163 #define STTS2004_DEVID		0x2201
164 #define STTS2004_DEVID_MASK	0xffff
165 
166 #define STTS3000_DEVID		0x0200
167 #define STTS3000_DEVID_MASK	0xffff
168 
169 static u16 jc42_hysteresis[] = { 0, 1500, 3000, 6000 };
170 
171 struct jc42_chips {
172 	u16 manid;
173 	u16 devid;
174 	u16 devid_mask;
175 };
176 
177 static struct jc42_chips jc42_chips[] = {
178 	{ ADT_MANID, ADT7408_DEVID, ADT7408_DEVID_MASK },
179 	{ ATMEL_MANID, AT30TS00_DEVID, AT30TS00_DEVID_MASK },
180 	{ ATMEL_MANID2, AT30TSE004_DEVID, AT30TSE004_DEVID_MASK },
181 	{ GT_MANID, GT30TS00_DEVID, GT30TS00_DEVID_MASK },
182 	{ GT_MANID2, GT34TS02_DEVID, GT34TS02_DEVID_MASK },
183 	{ IDT_MANID, TSE2004_DEVID, TSE2004_DEVID_MASK },
184 	{ IDT_MANID, TS3000_DEVID, TS3000_DEVID_MASK },
185 	{ IDT_MANID, TS3001_DEVID, TS3001_DEVID_MASK },
186 	{ MAX_MANID, MAX6604_DEVID, MAX6604_DEVID_MASK },
187 	{ MCP_MANID, MCP9804_DEVID, MCP9804_DEVID_MASK },
188 	{ MCP_MANID, MCP9808_DEVID, MCP9808_DEVID_MASK },
189 	{ MCP_MANID, MCP98242_DEVID, MCP98242_DEVID_MASK },
190 	{ MCP_MANID, MCP98243_DEVID, MCP98243_DEVID_MASK },
191 	{ MCP_MANID, MCP98244_DEVID, MCP98244_DEVID_MASK },
192 	{ MCP_MANID, MCP9843_DEVID, MCP9843_DEVID_MASK },
193 	{ NXP_MANID, SE97_DEVID, SE97_DEVID_MASK },
194 	{ ONS_MANID, CAT6095_DEVID, CAT6095_DEVID_MASK },
195 	{ ONS_MANID, CAT34TS02C_DEVID, CAT34TS02C_DEVID_MASK },
196 	{ ONS_MANID, CAT34TS04_DEVID, CAT34TS04_DEVID_MASK },
197 	{ NXP_MANID, SE98_DEVID, SE98_DEVID_MASK },
198 	{ STM_MANID, STTS424_DEVID, STTS424_DEVID_MASK },
199 	{ STM_MANID, STTS424E_DEVID, STTS424E_DEVID_MASK },
200 	{ STM_MANID, STTS2002_DEVID, STTS2002_DEVID_MASK },
201 	{ STM_MANID, STTS2004_DEVID, STTS2004_DEVID_MASK },
202 	{ STM_MANID, STTS3000_DEVID, STTS3000_DEVID_MASK },
203 };
204 
205 enum temp_index {
206 	t_input = 0,
207 	t_crit,
208 	t_min,
209 	t_max,
210 	t_num_temp
211 };
212 
213 static const u8 temp_regs[t_num_temp] = {
214 	[t_input] = JC42_REG_TEMP,
215 	[t_crit] = JC42_REG_TEMP_CRITICAL,
216 	[t_min] = JC42_REG_TEMP_LOWER,
217 	[t_max] = JC42_REG_TEMP_UPPER,
218 };
219 
220 /* Each client has this additional data */
221 struct jc42_data {
222 	struct i2c_client *client;
223 	struct mutex	update_lock;	/* protect register access */
224 	bool		extended;	/* true if extended range supported */
225 	bool		valid;
226 	unsigned long	last_updated;	/* In jiffies */
227 	u16		orig_config;	/* original configuration */
228 	u16		config;		/* current configuration */
229 	u16		temp[t_num_temp];/* Temperatures */
230 };
231 
232 #define JC42_TEMP_MIN_EXTENDED	(-40000)
233 #define JC42_TEMP_MIN		0
234 #define JC42_TEMP_MAX		125000
235 
jc42_temp_to_reg(long temp,bool extended)236 static u16 jc42_temp_to_reg(long temp, bool extended)
237 {
238 	int ntemp = clamp_val(temp,
239 			      extended ? JC42_TEMP_MIN_EXTENDED :
240 			      JC42_TEMP_MIN, JC42_TEMP_MAX);
241 
242 	/* convert from 0.001 to 0.0625 resolution */
243 	return (ntemp * 2 / 125) & 0x1fff;
244 }
245 
jc42_temp_from_reg(s16 reg)246 static int jc42_temp_from_reg(s16 reg)
247 {
248 	reg = sign_extend32(reg, 12);
249 
250 	/* convert from 0.0625 to 0.001 resolution */
251 	return reg * 125 / 2;
252 }
253 
jc42_update_device(struct device * dev)254 static struct jc42_data *jc42_update_device(struct device *dev)
255 {
256 	struct jc42_data *data = dev_get_drvdata(dev);
257 	struct i2c_client *client = data->client;
258 	struct jc42_data *ret = data;
259 	int i, val;
260 
261 	mutex_lock(&data->update_lock);
262 
263 	if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
264 		for (i = 0; i < t_num_temp; i++) {
265 			val = i2c_smbus_read_word_swapped(client, temp_regs[i]);
266 			if (val < 0) {
267 				ret = ERR_PTR(val);
268 				goto abort;
269 			}
270 			data->temp[i] = val;
271 		}
272 		data->last_updated = jiffies;
273 		data->valid = true;
274 	}
275 abort:
276 	mutex_unlock(&data->update_lock);
277 	return ret;
278 }
279 
jc42_read(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long * val)280 static int jc42_read(struct device *dev, enum hwmon_sensor_types type,
281 		     u32 attr, int channel, long *val)
282 {
283 	struct jc42_data *data = jc42_update_device(dev);
284 	int temp, hyst;
285 
286 	if (IS_ERR(data))
287 		return PTR_ERR(data);
288 
289 	switch (attr) {
290 	case hwmon_temp_input:
291 		*val = jc42_temp_from_reg(data->temp[t_input]);
292 		return 0;
293 	case hwmon_temp_min:
294 		*val = jc42_temp_from_reg(data->temp[t_min]);
295 		return 0;
296 	case hwmon_temp_max:
297 		*val = jc42_temp_from_reg(data->temp[t_max]);
298 		return 0;
299 	case hwmon_temp_crit:
300 		*val = jc42_temp_from_reg(data->temp[t_crit]);
301 		return 0;
302 	case hwmon_temp_max_hyst:
303 		temp = jc42_temp_from_reg(data->temp[t_max]);
304 		hyst = jc42_hysteresis[(data->config & JC42_CFG_HYST_MASK)
305 						>> JC42_CFG_HYST_SHIFT];
306 		*val = temp - hyst;
307 		return 0;
308 	case hwmon_temp_crit_hyst:
309 		temp = jc42_temp_from_reg(data->temp[t_crit]);
310 		hyst = jc42_hysteresis[(data->config & JC42_CFG_HYST_MASK)
311 						>> JC42_CFG_HYST_SHIFT];
312 		*val = temp - hyst;
313 		return 0;
314 	case hwmon_temp_min_alarm:
315 		*val = (data->temp[t_input] >> JC42_ALARM_MIN_BIT) & 1;
316 		return 0;
317 	case hwmon_temp_max_alarm:
318 		*val = (data->temp[t_input] >> JC42_ALARM_MAX_BIT) & 1;
319 		return 0;
320 	case hwmon_temp_crit_alarm:
321 		*val = (data->temp[t_input] >> JC42_ALARM_CRIT_BIT) & 1;
322 		return 0;
323 	default:
324 		return -EOPNOTSUPP;
325 	}
326 }
327 
jc42_write(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long val)328 static int jc42_write(struct device *dev, enum hwmon_sensor_types type,
329 		      u32 attr, int channel, long val)
330 {
331 	struct jc42_data *data = dev_get_drvdata(dev);
332 	struct i2c_client *client = data->client;
333 	int diff, hyst;
334 	int ret;
335 
336 	mutex_lock(&data->update_lock);
337 
338 	switch (attr) {
339 	case hwmon_temp_min:
340 		data->temp[t_min] = jc42_temp_to_reg(val, data->extended);
341 		ret = i2c_smbus_write_word_swapped(client, temp_regs[t_min],
342 						   data->temp[t_min]);
343 		break;
344 	case hwmon_temp_max:
345 		data->temp[t_max] = jc42_temp_to_reg(val, data->extended);
346 		ret = i2c_smbus_write_word_swapped(client, temp_regs[t_max],
347 						   data->temp[t_max]);
348 		break;
349 	case hwmon_temp_crit:
350 		data->temp[t_crit] = jc42_temp_to_reg(val, data->extended);
351 		ret = i2c_smbus_write_word_swapped(client, temp_regs[t_crit],
352 						   data->temp[t_crit]);
353 		break;
354 	case hwmon_temp_crit_hyst:
355 		/*
356 		 * JC42.4 compliant chips only support four hysteresis values.
357 		 * Pick best choice and go from there.
358 		 */
359 		val = clamp_val(val, (data->extended ? JC42_TEMP_MIN_EXTENDED
360 						     : JC42_TEMP_MIN) - 6000,
361 				JC42_TEMP_MAX);
362 		diff = jc42_temp_from_reg(data->temp[t_crit]) - val;
363 		hyst = 0;
364 		if (diff > 0) {
365 			if (diff < 2250)
366 				hyst = 1;	/* 1.5 degrees C */
367 			else if (diff < 4500)
368 				hyst = 2;	/* 3.0 degrees C */
369 			else
370 				hyst = 3;	/* 6.0 degrees C */
371 		}
372 		data->config = (data->config & ~JC42_CFG_HYST_MASK) |
373 				(hyst << JC42_CFG_HYST_SHIFT);
374 		ret = i2c_smbus_write_word_swapped(data->client,
375 						   JC42_REG_CONFIG,
376 						   data->config);
377 		break;
378 	default:
379 		ret = -EOPNOTSUPP;
380 		break;
381 	}
382 
383 	mutex_unlock(&data->update_lock);
384 
385 	return ret;
386 }
387 
jc42_is_visible(const void * _data,enum hwmon_sensor_types type,u32 attr,int channel)388 static umode_t jc42_is_visible(const void *_data, enum hwmon_sensor_types type,
389 			       u32 attr, int channel)
390 {
391 	const struct jc42_data *data = _data;
392 	unsigned int config = data->config;
393 	umode_t mode = S_IRUGO;
394 
395 	switch (attr) {
396 	case hwmon_temp_min:
397 	case hwmon_temp_max:
398 		if (!(config & JC42_CFG_EVENT_LOCK))
399 			mode |= S_IWUSR;
400 		break;
401 	case hwmon_temp_crit:
402 		if (!(config & JC42_CFG_TCRIT_LOCK))
403 			mode |= S_IWUSR;
404 		break;
405 	case hwmon_temp_crit_hyst:
406 		if (!(config & (JC42_CFG_EVENT_LOCK | JC42_CFG_TCRIT_LOCK)))
407 			mode |= S_IWUSR;
408 		break;
409 	case hwmon_temp_input:
410 	case hwmon_temp_max_hyst:
411 	case hwmon_temp_min_alarm:
412 	case hwmon_temp_max_alarm:
413 	case hwmon_temp_crit_alarm:
414 		break;
415 	default:
416 		mode = 0;
417 		break;
418 	}
419 	return mode;
420 }
421 
422 /* Return 0 if detection is successful, -ENODEV otherwise */
jc42_detect(struct i2c_client * client,struct i2c_board_info * info)423 static int jc42_detect(struct i2c_client *client, struct i2c_board_info *info)
424 {
425 	struct i2c_adapter *adapter = client->adapter;
426 	int i, config, cap, manid, devid;
427 
428 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
429 				     I2C_FUNC_SMBUS_WORD_DATA))
430 		return -ENODEV;
431 
432 	cap = i2c_smbus_read_word_swapped(client, JC42_REG_CAP);
433 	config = i2c_smbus_read_word_swapped(client, JC42_REG_CONFIG);
434 	manid = i2c_smbus_read_word_swapped(client, JC42_REG_MANID);
435 	devid = i2c_smbus_read_word_swapped(client, JC42_REG_DEVICEID);
436 
437 	if (cap < 0 || config < 0 || manid < 0 || devid < 0)
438 		return -ENODEV;
439 
440 	if ((cap & 0xff00) || (config & 0xf800))
441 		return -ENODEV;
442 
443 	for (i = 0; i < ARRAY_SIZE(jc42_chips); i++) {
444 		struct jc42_chips *chip = &jc42_chips[i];
445 		if (manid == chip->manid &&
446 		    (devid & chip->devid_mask) == chip->devid) {
447 			strlcpy(info->type, "jc42", I2C_NAME_SIZE);
448 			return 0;
449 		}
450 	}
451 	return -ENODEV;
452 }
453 
454 static const u32 jc42_temp_config[] = {
455 	HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX | HWMON_T_CRIT |
456 	HWMON_T_MAX_HYST | HWMON_T_CRIT_HYST |
457 	HWMON_T_MIN_ALARM | HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM,
458 	0
459 };
460 
461 static const struct hwmon_channel_info jc42_temp = {
462 	.type = hwmon_temp,
463 	.config = jc42_temp_config,
464 };
465 
466 static const struct hwmon_channel_info *jc42_info[] = {
467 	&jc42_temp,
468 	NULL
469 };
470 
471 static const struct hwmon_ops jc42_hwmon_ops = {
472 	.is_visible = jc42_is_visible,
473 	.read = jc42_read,
474 	.write = jc42_write,
475 };
476 
477 static const struct hwmon_chip_info jc42_chip_info = {
478 	.ops = &jc42_hwmon_ops,
479 	.info = jc42_info,
480 };
481 
jc42_probe(struct i2c_client * client,const struct i2c_device_id * id)482 static int jc42_probe(struct i2c_client *client, const struct i2c_device_id *id)
483 {
484 	struct device *dev = &client->dev;
485 	struct device *hwmon_dev;
486 	struct jc42_data *data;
487 	int config, cap;
488 
489 	data = devm_kzalloc(dev, sizeof(struct jc42_data), GFP_KERNEL);
490 	if (!data)
491 		return -ENOMEM;
492 
493 	data->client = client;
494 	i2c_set_clientdata(client, data);
495 	mutex_init(&data->update_lock);
496 
497 	cap = i2c_smbus_read_word_swapped(client, JC42_REG_CAP);
498 	if (cap < 0)
499 		return cap;
500 
501 	data->extended = !!(cap & JC42_CAP_RANGE);
502 
503 	if (device_property_read_bool(dev, "smbus-timeout-disable")) {
504 		int smbus;
505 
506 		/*
507 		 * Not all chips support this register, but from a
508 		 * quick read of various datasheets no chip appears
509 		 * incompatible with the below attempt to disable
510 		 * the timeout. And the whole thing is opt-in...
511 		 */
512 		smbus = i2c_smbus_read_word_swapped(client, JC42_REG_SMBUS);
513 		if (smbus < 0)
514 			return smbus;
515 		i2c_smbus_write_word_swapped(client, JC42_REG_SMBUS,
516 					     smbus | SMBUS_STMOUT);
517 	}
518 
519 	config = i2c_smbus_read_word_swapped(client, JC42_REG_CONFIG);
520 	if (config < 0)
521 		return config;
522 
523 	data->orig_config = config;
524 	if (config & JC42_CFG_SHUTDOWN) {
525 		config &= ~JC42_CFG_SHUTDOWN;
526 		i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG, config);
527 	}
528 	data->config = config;
529 
530 	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
531 							 data, &jc42_chip_info,
532 							 NULL);
533 	return PTR_ERR_OR_ZERO(hwmon_dev);
534 }
535 
jc42_remove(struct i2c_client * client)536 static int jc42_remove(struct i2c_client *client)
537 {
538 	struct jc42_data *data = i2c_get_clientdata(client);
539 
540 	/* Restore original configuration except hysteresis */
541 	if ((data->config & ~JC42_CFG_HYST_MASK) !=
542 	    (data->orig_config & ~JC42_CFG_HYST_MASK)) {
543 		int config;
544 
545 		config = (data->orig_config & ~JC42_CFG_HYST_MASK)
546 		  | (data->config & JC42_CFG_HYST_MASK);
547 		i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG, config);
548 	}
549 	return 0;
550 }
551 
552 #ifdef CONFIG_PM
553 
jc42_suspend(struct device * dev)554 static int jc42_suspend(struct device *dev)
555 {
556 	struct jc42_data *data = dev_get_drvdata(dev);
557 
558 	data->config |= JC42_CFG_SHUTDOWN;
559 	i2c_smbus_write_word_swapped(data->client, JC42_REG_CONFIG,
560 				     data->config);
561 	return 0;
562 }
563 
jc42_resume(struct device * dev)564 static int jc42_resume(struct device *dev)
565 {
566 	struct jc42_data *data = dev_get_drvdata(dev);
567 
568 	data->config &= ~JC42_CFG_SHUTDOWN;
569 	i2c_smbus_write_word_swapped(data->client, JC42_REG_CONFIG,
570 				     data->config);
571 	return 0;
572 }
573 
574 static const struct dev_pm_ops jc42_dev_pm_ops = {
575 	.suspend = jc42_suspend,
576 	.resume = jc42_resume,
577 };
578 
579 #define JC42_DEV_PM_OPS (&jc42_dev_pm_ops)
580 #else
581 #define JC42_DEV_PM_OPS NULL
582 #endif /* CONFIG_PM */
583 
584 static const struct i2c_device_id jc42_id[] = {
585 	{ "jc42", 0 },
586 	{ }
587 };
588 MODULE_DEVICE_TABLE(i2c, jc42_id);
589 
590 #ifdef CONFIG_OF
591 static const struct of_device_id jc42_of_ids[] = {
592 	{ .compatible = "jedec,jc-42.4-temp", },
593 	{ }
594 };
595 MODULE_DEVICE_TABLE(of, jc42_of_ids);
596 #endif
597 
598 static struct i2c_driver jc42_driver = {
599 	.class		= I2C_CLASS_SPD | I2C_CLASS_HWMON,
600 	.driver = {
601 		.name	= "jc42",
602 		.pm = JC42_DEV_PM_OPS,
603 		.of_match_table = of_match_ptr(jc42_of_ids),
604 	},
605 	.probe		= jc42_probe,
606 	.remove		= jc42_remove,
607 	.id_table	= jc42_id,
608 	.detect		= jc42_detect,
609 	.address_list	= normal_i2c,
610 };
611 
612 module_i2c_driver(jc42_driver);
613 
614 MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>");
615 MODULE_DESCRIPTION("JC42 driver");
616 MODULE_LICENSE("GPL");
617