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 
23 /* Addresses to scan */
24 static const unsigned short normal_i2c[] = {
25 	0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, I2C_CLIENT_END };
26 
27 /* JC42 registers. All registers are 16 bit. */
28 #define JC42_REG_CAP		0x00
29 #define JC42_REG_CONFIG		0x01
30 #define JC42_REG_TEMP_UPPER	0x02
31 #define JC42_REG_TEMP_LOWER	0x03
32 #define JC42_REG_TEMP_CRITICAL	0x04
33 #define JC42_REG_TEMP		0x05
34 #define JC42_REG_MANID		0x06
35 #define JC42_REG_DEVICEID	0x07
36 #define JC42_REG_SMBUS		0x22 /* NXP and Atmel, possibly others? */
37 
38 /* Status bits in temperature register */
39 #define JC42_ALARM_CRIT_BIT	15
40 #define JC42_ALARM_MAX_BIT	14
41 #define JC42_ALARM_MIN_BIT	13
42 
43 /* Configuration register defines */
44 #define JC42_CFG_CRIT_ONLY	(1 << 2)
45 #define JC42_CFG_TCRIT_LOCK	(1 << 6)
46 #define JC42_CFG_EVENT_LOCK	(1 << 7)
47 #define JC42_CFG_SHUTDOWN	(1 << 8)
48 #define JC42_CFG_HYST_SHIFT	9
49 #define JC42_CFG_HYST_MASK	(0x03 << 9)
50 
51 /* Capabilities */
52 #define JC42_CAP_RANGE		(1 << 2)
53 
54 /* Manufacturer IDs */
55 #define ADT_MANID		0x11d4  /* Analog Devices */
56 #define ATMEL_MANID		0x001f  /* Atmel */
57 #define ATMEL_MANID2		0x1114	/* Atmel */
58 #define MAX_MANID		0x004d  /* Maxim */
59 #define IDT_MANID		0x00b3  /* IDT */
60 #define MCP_MANID		0x0054  /* Microchip */
61 #define NXP_MANID		0x1131  /* NXP Semiconductors */
62 #define ONS_MANID		0x1b09  /* ON Semiconductor */
63 #define STM_MANID		0x104a  /* ST Microelectronics */
64 #define GT_MANID		0x1c68	/* Giantec */
65 #define GT_MANID2		0x132d	/* Giantec, 2nd mfg ID */
66 #define SI_MANID		0x1c85	/* Seiko Instruments */
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 #define N34TS04_DEVID		0x2230
142 #define N34TS04_DEVID_MASK	0xfff0
143 
144 /* ST Microelectronics */
145 #define STTS424_DEVID		0x0101
146 #define STTS424_DEVID_MASK	0xffff
147 
148 #define STTS424E_DEVID		0x0000
149 #define STTS424E_DEVID_MASK	0xfffe
150 
151 #define STTS2002_DEVID		0x0300
152 #define STTS2002_DEVID_MASK	0xffff
153 
154 #define STTS2004_DEVID		0x2201
155 #define STTS2004_DEVID_MASK	0xffff
156 
157 #define STTS3000_DEVID		0x0200
158 #define STTS3000_DEVID_MASK	0xffff
159 
160 /* Seiko Instruments */
161 #define S34TS04A_DEVID		0x2221
162 #define S34TS04A_DEVID_MASK	0xffff
163 
164 static u16 jc42_hysteresis[] = { 0, 1500, 3000, 6000 };
165 
166 struct jc42_chips {
167 	u16 manid;
168 	u16 devid;
169 	u16 devid_mask;
170 };
171 
172 static struct jc42_chips jc42_chips[] = {
173 	{ ADT_MANID, ADT7408_DEVID, ADT7408_DEVID_MASK },
174 	{ ATMEL_MANID, AT30TS00_DEVID, AT30TS00_DEVID_MASK },
175 	{ ATMEL_MANID2, AT30TSE004_DEVID, AT30TSE004_DEVID_MASK },
176 	{ GT_MANID, GT30TS00_DEVID, GT30TS00_DEVID_MASK },
177 	{ GT_MANID2, GT34TS02_DEVID, GT34TS02_DEVID_MASK },
178 	{ IDT_MANID, TSE2004_DEVID, TSE2004_DEVID_MASK },
179 	{ IDT_MANID, TS3000_DEVID, TS3000_DEVID_MASK },
180 	{ IDT_MANID, TS3001_DEVID, TS3001_DEVID_MASK },
181 	{ MAX_MANID, MAX6604_DEVID, MAX6604_DEVID_MASK },
182 	{ MCP_MANID, MCP9804_DEVID, MCP9804_DEVID_MASK },
183 	{ MCP_MANID, MCP9808_DEVID, MCP9808_DEVID_MASK },
184 	{ MCP_MANID, MCP98242_DEVID, MCP98242_DEVID_MASK },
185 	{ MCP_MANID, MCP98243_DEVID, MCP98243_DEVID_MASK },
186 	{ MCP_MANID, MCP98244_DEVID, MCP98244_DEVID_MASK },
187 	{ MCP_MANID, MCP9843_DEVID, MCP9843_DEVID_MASK },
188 	{ NXP_MANID, SE97_DEVID, SE97_DEVID_MASK },
189 	{ ONS_MANID, CAT6095_DEVID, CAT6095_DEVID_MASK },
190 	{ ONS_MANID, CAT34TS02C_DEVID, CAT34TS02C_DEVID_MASK },
191 	{ ONS_MANID, CAT34TS04_DEVID, CAT34TS04_DEVID_MASK },
192 	{ ONS_MANID, N34TS04_DEVID, N34TS04_DEVID_MASK },
193 	{ NXP_MANID, SE98_DEVID, SE98_DEVID_MASK },
194 	{ SI_MANID,  S34TS04A_DEVID, S34TS04A_DEVID_MASK },
195 	{ STM_MANID, STTS424_DEVID, STTS424_DEVID_MASK },
196 	{ STM_MANID, STTS424E_DEVID, STTS424E_DEVID_MASK },
197 	{ STM_MANID, STTS2002_DEVID, STTS2002_DEVID_MASK },
198 	{ STM_MANID, STTS2004_DEVID, STTS2004_DEVID_MASK },
199 	{ STM_MANID, STTS3000_DEVID, STTS3000_DEVID_MASK },
200 };
201 
202 enum temp_index {
203 	t_input = 0,
204 	t_crit,
205 	t_min,
206 	t_max,
207 	t_num_temp
208 };
209 
210 static const u8 temp_regs[t_num_temp] = {
211 	[t_input] = JC42_REG_TEMP,
212 	[t_crit] = JC42_REG_TEMP_CRITICAL,
213 	[t_min] = JC42_REG_TEMP_LOWER,
214 	[t_max] = JC42_REG_TEMP_UPPER,
215 };
216 
217 /* Each client has this additional data */
218 struct jc42_data {
219 	struct i2c_client *client;
220 	struct mutex	update_lock;	/* protect register access */
221 	bool		extended;	/* true if extended range supported */
222 	bool		valid;
223 	unsigned long	last_updated;	/* In jiffies */
224 	u16		orig_config;	/* original configuration */
225 	u16		config;		/* current configuration */
226 	u16		temp[t_num_temp];/* Temperatures */
227 };
228 
229 #define JC42_TEMP_MIN_EXTENDED	(-40000)
230 #define JC42_TEMP_MIN		0
231 #define JC42_TEMP_MAX		125000
232 
jc42_temp_to_reg(long temp,bool extended)233 static u16 jc42_temp_to_reg(long temp, bool extended)
234 {
235 	int ntemp = clamp_val(temp,
236 			      extended ? JC42_TEMP_MIN_EXTENDED :
237 			      JC42_TEMP_MIN, JC42_TEMP_MAX);
238 
239 	/* convert from 0.001 to 0.0625 resolution */
240 	return (ntemp * 2 / 125) & 0x1fff;
241 }
242 
jc42_temp_from_reg(s16 reg)243 static int jc42_temp_from_reg(s16 reg)
244 {
245 	reg = sign_extend32(reg, 12);
246 
247 	/* convert from 0.0625 to 0.001 resolution */
248 	return reg * 125 / 2;
249 }
250 
jc42_update_device(struct device * dev)251 static struct jc42_data *jc42_update_device(struct device *dev)
252 {
253 	struct jc42_data *data = dev_get_drvdata(dev);
254 	struct i2c_client *client = data->client;
255 	struct jc42_data *ret = data;
256 	int i, val;
257 
258 	mutex_lock(&data->update_lock);
259 
260 	if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
261 		for (i = 0; i < t_num_temp; i++) {
262 			val = i2c_smbus_read_word_swapped(client, temp_regs[i]);
263 			if (val < 0) {
264 				ret = ERR_PTR(val);
265 				goto abort;
266 			}
267 			data->temp[i] = val;
268 		}
269 		data->last_updated = jiffies;
270 		data->valid = true;
271 	}
272 abort:
273 	mutex_unlock(&data->update_lock);
274 	return ret;
275 }
276 
jc42_read(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long * val)277 static int jc42_read(struct device *dev, enum hwmon_sensor_types type,
278 		     u32 attr, int channel, long *val)
279 {
280 	struct jc42_data *data = jc42_update_device(dev);
281 	int temp, hyst;
282 
283 	if (IS_ERR(data))
284 		return PTR_ERR(data);
285 
286 	switch (attr) {
287 	case hwmon_temp_input:
288 		*val = jc42_temp_from_reg(data->temp[t_input]);
289 		return 0;
290 	case hwmon_temp_min:
291 		*val = jc42_temp_from_reg(data->temp[t_min]);
292 		return 0;
293 	case hwmon_temp_max:
294 		*val = jc42_temp_from_reg(data->temp[t_max]);
295 		return 0;
296 	case hwmon_temp_crit:
297 		*val = jc42_temp_from_reg(data->temp[t_crit]);
298 		return 0;
299 	case hwmon_temp_max_hyst:
300 		temp = jc42_temp_from_reg(data->temp[t_max]);
301 		hyst = jc42_hysteresis[(data->config & JC42_CFG_HYST_MASK)
302 						>> JC42_CFG_HYST_SHIFT];
303 		*val = temp - hyst;
304 		return 0;
305 	case hwmon_temp_crit_hyst:
306 		temp = jc42_temp_from_reg(data->temp[t_crit]);
307 		hyst = jc42_hysteresis[(data->config & JC42_CFG_HYST_MASK)
308 						>> JC42_CFG_HYST_SHIFT];
309 		*val = temp - hyst;
310 		return 0;
311 	case hwmon_temp_min_alarm:
312 		*val = (data->temp[t_input] >> JC42_ALARM_MIN_BIT) & 1;
313 		return 0;
314 	case hwmon_temp_max_alarm:
315 		*val = (data->temp[t_input] >> JC42_ALARM_MAX_BIT) & 1;
316 		return 0;
317 	case hwmon_temp_crit_alarm:
318 		*val = (data->temp[t_input] >> JC42_ALARM_CRIT_BIT) & 1;
319 		return 0;
320 	default:
321 		return -EOPNOTSUPP;
322 	}
323 }
324 
jc42_write(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long val)325 static int jc42_write(struct device *dev, enum hwmon_sensor_types type,
326 		      u32 attr, int channel, long val)
327 {
328 	struct jc42_data *data = dev_get_drvdata(dev);
329 	struct i2c_client *client = data->client;
330 	int diff, hyst;
331 	int ret;
332 
333 	mutex_lock(&data->update_lock);
334 
335 	switch (attr) {
336 	case hwmon_temp_min:
337 		data->temp[t_min] = jc42_temp_to_reg(val, data->extended);
338 		ret = i2c_smbus_write_word_swapped(client, temp_regs[t_min],
339 						   data->temp[t_min]);
340 		break;
341 	case hwmon_temp_max:
342 		data->temp[t_max] = jc42_temp_to_reg(val, data->extended);
343 		ret = i2c_smbus_write_word_swapped(client, temp_regs[t_max],
344 						   data->temp[t_max]);
345 		break;
346 	case hwmon_temp_crit:
347 		data->temp[t_crit] = jc42_temp_to_reg(val, data->extended);
348 		ret = i2c_smbus_write_word_swapped(client, temp_regs[t_crit],
349 						   data->temp[t_crit]);
350 		break;
351 	case hwmon_temp_crit_hyst:
352 		/*
353 		 * JC42.4 compliant chips only support four hysteresis values.
354 		 * Pick best choice and go from there.
355 		 */
356 		val = clamp_val(val, (data->extended ? JC42_TEMP_MIN_EXTENDED
357 						     : JC42_TEMP_MIN) - 6000,
358 				JC42_TEMP_MAX);
359 		diff = jc42_temp_from_reg(data->temp[t_crit]) - val;
360 		hyst = 0;
361 		if (diff > 0) {
362 			if (diff < 2250)
363 				hyst = 1;	/* 1.5 degrees C */
364 			else if (diff < 4500)
365 				hyst = 2;	/* 3.0 degrees C */
366 			else
367 				hyst = 3;	/* 6.0 degrees C */
368 		}
369 		data->config = (data->config & ~JC42_CFG_HYST_MASK) |
370 				(hyst << JC42_CFG_HYST_SHIFT);
371 		ret = i2c_smbus_write_word_swapped(data->client,
372 						   JC42_REG_CONFIG,
373 						   data->config);
374 		break;
375 	default:
376 		ret = -EOPNOTSUPP;
377 		break;
378 	}
379 
380 	mutex_unlock(&data->update_lock);
381 
382 	return ret;
383 }
384 
jc42_is_visible(const void * _data,enum hwmon_sensor_types type,u32 attr,int channel)385 static umode_t jc42_is_visible(const void *_data, enum hwmon_sensor_types type,
386 			       u32 attr, int channel)
387 {
388 	const struct jc42_data *data = _data;
389 	unsigned int config = data->config;
390 	umode_t mode = 0444;
391 
392 	switch (attr) {
393 	case hwmon_temp_min:
394 	case hwmon_temp_max:
395 		if (!(config & JC42_CFG_EVENT_LOCK))
396 			mode |= 0200;
397 		break;
398 	case hwmon_temp_crit:
399 		if (!(config & JC42_CFG_TCRIT_LOCK))
400 			mode |= 0200;
401 		break;
402 	case hwmon_temp_crit_hyst:
403 		if (!(config & (JC42_CFG_EVENT_LOCK | JC42_CFG_TCRIT_LOCK)))
404 			mode |= 0200;
405 		break;
406 	case hwmon_temp_input:
407 	case hwmon_temp_max_hyst:
408 	case hwmon_temp_min_alarm:
409 	case hwmon_temp_max_alarm:
410 	case hwmon_temp_crit_alarm:
411 		break;
412 	default:
413 		mode = 0;
414 		break;
415 	}
416 	return mode;
417 }
418 
419 /* Return 0 if detection is successful, -ENODEV otherwise */
jc42_detect(struct i2c_client * client,struct i2c_board_info * info)420 static int jc42_detect(struct i2c_client *client, struct i2c_board_info *info)
421 {
422 	struct i2c_adapter *adapter = client->adapter;
423 	int i, config, cap, manid, devid;
424 
425 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
426 				     I2C_FUNC_SMBUS_WORD_DATA))
427 		return -ENODEV;
428 
429 	cap = i2c_smbus_read_word_swapped(client, JC42_REG_CAP);
430 	config = i2c_smbus_read_word_swapped(client, JC42_REG_CONFIG);
431 	manid = i2c_smbus_read_word_swapped(client, JC42_REG_MANID);
432 	devid = i2c_smbus_read_word_swapped(client, JC42_REG_DEVICEID);
433 
434 	if (cap < 0 || config < 0 || manid < 0 || devid < 0)
435 		return -ENODEV;
436 
437 	if ((cap & 0xff00) || (config & 0xf800))
438 		return -ENODEV;
439 
440 	for (i = 0; i < ARRAY_SIZE(jc42_chips); i++) {
441 		struct jc42_chips *chip = &jc42_chips[i];
442 		if (manid == chip->manid &&
443 		    (devid & chip->devid_mask) == chip->devid) {
444 			strlcpy(info->type, "jc42", I2C_NAME_SIZE);
445 			return 0;
446 		}
447 	}
448 	return -ENODEV;
449 }
450 
451 static const struct hwmon_channel_info *jc42_info[] = {
452 	HWMON_CHANNEL_INFO(chip,
453 			   HWMON_C_REGISTER_TZ | HWMON_C_UPDATE_INTERVAL),
454 	HWMON_CHANNEL_INFO(temp,
455 			   HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
456 			   HWMON_T_CRIT | HWMON_T_MAX_HYST |
457 			   HWMON_T_CRIT_HYST | HWMON_T_MIN_ALARM |
458 			   HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM),
459 	NULL
460 };
461 
462 static const struct hwmon_ops jc42_hwmon_ops = {
463 	.is_visible = jc42_is_visible,
464 	.read = jc42_read,
465 	.write = jc42_write,
466 };
467 
468 static const struct hwmon_chip_info jc42_chip_info = {
469 	.ops = &jc42_hwmon_ops,
470 	.info = jc42_info,
471 };
472 
jc42_probe(struct i2c_client * client)473 static int jc42_probe(struct i2c_client *client)
474 {
475 	struct device *dev = &client->dev;
476 	struct device *hwmon_dev;
477 	struct jc42_data *data;
478 	int config, cap;
479 
480 	data = devm_kzalloc(dev, sizeof(struct jc42_data), GFP_KERNEL);
481 	if (!data)
482 		return -ENOMEM;
483 
484 	data->client = client;
485 	i2c_set_clientdata(client, data);
486 	mutex_init(&data->update_lock);
487 
488 	cap = i2c_smbus_read_word_swapped(client, JC42_REG_CAP);
489 	if (cap < 0)
490 		return cap;
491 
492 	data->extended = !!(cap & JC42_CAP_RANGE);
493 
494 	if (device_property_read_bool(dev, "smbus-timeout-disable")) {
495 		int smbus;
496 
497 		/*
498 		 * Not all chips support this register, but from a
499 		 * quick read of various datasheets no chip appears
500 		 * incompatible with the below attempt to disable
501 		 * the timeout. And the whole thing is opt-in...
502 		 */
503 		smbus = i2c_smbus_read_word_swapped(client, JC42_REG_SMBUS);
504 		if (smbus < 0)
505 			return smbus;
506 		i2c_smbus_write_word_swapped(client, JC42_REG_SMBUS,
507 					     smbus | SMBUS_STMOUT);
508 	}
509 
510 	config = i2c_smbus_read_word_swapped(client, JC42_REG_CONFIG);
511 	if (config < 0)
512 		return config;
513 
514 	data->orig_config = config;
515 	if (config & JC42_CFG_SHUTDOWN) {
516 		config &= ~JC42_CFG_SHUTDOWN;
517 		i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG, config);
518 	}
519 	data->config = config;
520 
521 	hwmon_dev = devm_hwmon_device_register_with_info(dev, "jc42",
522 							 data, &jc42_chip_info,
523 							 NULL);
524 	return PTR_ERR_OR_ZERO(hwmon_dev);
525 }
526 
jc42_remove(struct i2c_client * client)527 static int jc42_remove(struct i2c_client *client)
528 {
529 	struct jc42_data *data = i2c_get_clientdata(client);
530 
531 	/* Restore original configuration except hysteresis */
532 	if ((data->config & ~JC42_CFG_HYST_MASK) !=
533 	    (data->orig_config & ~JC42_CFG_HYST_MASK)) {
534 		int config;
535 
536 		config = (data->orig_config & ~JC42_CFG_HYST_MASK)
537 		  | (data->config & JC42_CFG_HYST_MASK);
538 		i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG, config);
539 	}
540 	return 0;
541 }
542 
543 #ifdef CONFIG_PM
544 
jc42_suspend(struct device * dev)545 static int jc42_suspend(struct device *dev)
546 {
547 	struct jc42_data *data = dev_get_drvdata(dev);
548 
549 	data->config |= JC42_CFG_SHUTDOWN;
550 	i2c_smbus_write_word_swapped(data->client, JC42_REG_CONFIG,
551 				     data->config);
552 	return 0;
553 }
554 
jc42_resume(struct device * dev)555 static int jc42_resume(struct device *dev)
556 {
557 	struct jc42_data *data = dev_get_drvdata(dev);
558 
559 	data->config &= ~JC42_CFG_SHUTDOWN;
560 	i2c_smbus_write_word_swapped(data->client, JC42_REG_CONFIG,
561 				     data->config);
562 	return 0;
563 }
564 
565 static const struct dev_pm_ops jc42_dev_pm_ops = {
566 	.suspend = jc42_suspend,
567 	.resume = jc42_resume,
568 };
569 
570 #define JC42_DEV_PM_OPS (&jc42_dev_pm_ops)
571 #else
572 #define JC42_DEV_PM_OPS NULL
573 #endif /* CONFIG_PM */
574 
575 static const struct i2c_device_id jc42_id[] = {
576 	{ "jc42", 0 },
577 	{ }
578 };
579 MODULE_DEVICE_TABLE(i2c, jc42_id);
580 
581 #ifdef CONFIG_OF
582 static const struct of_device_id jc42_of_ids[] = {
583 	{ .compatible = "jedec,jc-42.4-temp", },
584 	{ }
585 };
586 MODULE_DEVICE_TABLE(of, jc42_of_ids);
587 #endif
588 
589 static struct i2c_driver jc42_driver = {
590 	.class		= I2C_CLASS_SPD | I2C_CLASS_HWMON,
591 	.driver = {
592 		.name	= "jc42",
593 		.pm = JC42_DEV_PM_OPS,
594 		.of_match_table = of_match_ptr(jc42_of_ids),
595 	},
596 	.probe_new	= jc42_probe,
597 	.remove		= jc42_remove,
598 	.id_table	= jc42_id,
599 	.detect		= jc42_detect,
600 	.address_list	= normal_i2c,
601 };
602 
603 module_i2c_driver(jc42_driver);
604 
605 MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>");
606 MODULE_DESCRIPTION("JC42 driver");
607 MODULE_LICENSE("GPL");
608