xref: /openbmc/linux/drivers/hwmon/nct7802.c (revision 4e95bc26)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * nct7802 - Driver for Nuvoton NCT7802Y
4  *
5  * Copyright (C) 2014  Guenter Roeck <linux@roeck-us.net>
6  */
7 
8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9 
10 #include <linux/err.h>
11 #include <linux/i2c.h>
12 #include <linux/init.h>
13 #include <linux/hwmon.h>
14 #include <linux/hwmon-sysfs.h>
15 #include <linux/jiffies.h>
16 #include <linux/module.h>
17 #include <linux/mutex.h>
18 #include <linux/regmap.h>
19 #include <linux/slab.h>
20 
21 #define DRVNAME "nct7802"
22 
23 static const u8 REG_VOLTAGE[5] = { 0x09, 0x0a, 0x0c, 0x0d, 0x0e };
24 
25 static const u8 REG_VOLTAGE_LIMIT_LSB[2][5] = {
26 	{ 0x40, 0x00, 0x42, 0x44, 0x46 },
27 	{ 0x3f, 0x00, 0x41, 0x43, 0x45 },
28 };
29 
30 static const u8 REG_VOLTAGE_LIMIT_MSB[5] = { 0x48, 0x00, 0x47, 0x47, 0x48 };
31 
32 static const u8 REG_VOLTAGE_LIMIT_MSB_SHIFT[2][5] = {
33 	{ 0, 0, 4, 0, 4 },
34 	{ 2, 0, 6, 2, 6 },
35 };
36 
37 #define REG_BANK		0x00
38 #define REG_TEMP_LSB		0x05
39 #define REG_TEMP_PECI_LSB	0x08
40 #define REG_VOLTAGE_LOW		0x0f
41 #define REG_FANCOUNT_LOW	0x13
42 #define REG_START		0x21
43 #define REG_MODE		0x22 /* 7.2.32 Mode Selection Register */
44 #define REG_PECI_ENABLE		0x23
45 #define REG_FAN_ENABLE		0x24
46 #define REG_VMON_ENABLE		0x25
47 #define REG_PWM(x)		(0x60 + (x))
48 #define REG_SMARTFAN_EN(x)      (0x64 + (x) / 2)
49 #define SMARTFAN_EN_SHIFT(x)    ((x) % 2 * 4)
50 #define REG_VENDOR_ID		0xfd
51 #define REG_CHIP_ID		0xfe
52 #define REG_VERSION_ID		0xff
53 
54 /*
55  * Data structures and manipulation thereof
56  */
57 
58 struct nct7802_data {
59 	struct regmap *regmap;
60 	struct mutex access_lock; /* for multi-byte read and write operations */
61 };
62 
63 static ssize_t temp_type_show(struct device *dev,
64 			      struct device_attribute *attr, char *buf)
65 {
66 	struct nct7802_data *data = dev_get_drvdata(dev);
67 	struct sensor_device_attribute *sattr = to_sensor_dev_attr(attr);
68 	unsigned int mode;
69 	int ret;
70 
71 	ret = regmap_read(data->regmap, REG_MODE, &mode);
72 	if (ret < 0)
73 		return ret;
74 
75 	return sprintf(buf, "%u\n", (mode >> (2 * sattr->index) & 3) + 2);
76 }
77 
78 static ssize_t temp_type_store(struct device *dev,
79 			       struct device_attribute *attr, const char *buf,
80 			       size_t count)
81 {
82 	struct nct7802_data *data = dev_get_drvdata(dev);
83 	struct sensor_device_attribute *sattr = to_sensor_dev_attr(attr);
84 	unsigned int type;
85 	int err;
86 
87 	err = kstrtouint(buf, 0, &type);
88 	if (err < 0)
89 		return err;
90 	if (sattr->index == 2 && type != 4) /* RD3 */
91 		return -EINVAL;
92 	if (type < 3 || type > 4)
93 		return -EINVAL;
94 	err = regmap_update_bits(data->regmap, REG_MODE,
95 			3 << 2 * sattr->index, (type - 2) << 2 * sattr->index);
96 	return err ? : count;
97 }
98 
99 static ssize_t pwm_mode_show(struct device *dev,
100 			     struct device_attribute *attr, char *buf)
101 {
102 	struct sensor_device_attribute *sattr = to_sensor_dev_attr(attr);
103 	struct nct7802_data *data = dev_get_drvdata(dev);
104 	unsigned int regval;
105 	int ret;
106 
107 	if (sattr->index > 1)
108 		return sprintf(buf, "1\n");
109 
110 	ret = regmap_read(data->regmap, 0x5E, &regval);
111 	if (ret < 0)
112 		return ret;
113 
114 	return sprintf(buf, "%u\n", !(regval & (1 << sattr->index)));
115 }
116 
117 static ssize_t pwm_show(struct device *dev, struct device_attribute *devattr,
118 			char *buf)
119 {
120 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
121 	struct nct7802_data *data = dev_get_drvdata(dev);
122 	unsigned int val;
123 	int ret;
124 
125 	if (!attr->index)
126 		return sprintf(buf, "255\n");
127 
128 	ret = regmap_read(data->regmap, attr->index, &val);
129 	if (ret < 0)
130 		return ret;
131 
132 	return sprintf(buf, "%d\n", val);
133 }
134 
135 static ssize_t pwm_store(struct device *dev, struct device_attribute *devattr,
136 			 const char *buf, size_t count)
137 {
138 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
139 	struct nct7802_data *data = dev_get_drvdata(dev);
140 	int err;
141 	u8 val;
142 
143 	err = kstrtou8(buf, 0, &val);
144 	if (err < 0)
145 		return err;
146 
147 	err = regmap_write(data->regmap, attr->index, val);
148 	return err ? : count;
149 }
150 
151 static ssize_t pwm_enable_show(struct device *dev,
152 			       struct device_attribute *attr, char *buf)
153 {
154 	struct nct7802_data *data = dev_get_drvdata(dev);
155 	struct sensor_device_attribute *sattr = to_sensor_dev_attr(attr);
156 	unsigned int reg, enabled;
157 	int ret;
158 
159 	ret = regmap_read(data->regmap, REG_SMARTFAN_EN(sattr->index), &reg);
160 	if (ret < 0)
161 		return ret;
162 	enabled = reg >> SMARTFAN_EN_SHIFT(sattr->index) & 1;
163 	return sprintf(buf, "%u\n", enabled + 1);
164 }
165 
166 static ssize_t pwm_enable_store(struct device *dev,
167 				struct device_attribute *attr,
168 				const char *buf, size_t count)
169 {
170 	struct nct7802_data *data = dev_get_drvdata(dev);
171 	struct sensor_device_attribute *sattr = to_sensor_dev_attr(attr);
172 	u8 val;
173 	int ret;
174 
175 	ret = kstrtou8(buf, 0, &val);
176 	if (ret < 0)
177 		return ret;
178 	if (val < 1 || val > 2)
179 		return -EINVAL;
180 	ret = regmap_update_bits(data->regmap, REG_SMARTFAN_EN(sattr->index),
181 				 1 << SMARTFAN_EN_SHIFT(sattr->index),
182 				 (val - 1) << SMARTFAN_EN_SHIFT(sattr->index));
183 	return ret ? : count;
184 }
185 
186 static int nct7802_read_temp(struct nct7802_data *data,
187 			     u8 reg_temp, u8 reg_temp_low, int *temp)
188 {
189 	unsigned int t1, t2 = 0;
190 	int err;
191 
192 	*temp = 0;
193 
194 	mutex_lock(&data->access_lock);
195 	err = regmap_read(data->regmap, reg_temp, &t1);
196 	if (err < 0)
197 		goto abort;
198 	t1 <<= 8;
199 	if (reg_temp_low) {	/* 11 bit data */
200 		err = regmap_read(data->regmap, reg_temp_low, &t2);
201 		if (err < 0)
202 			goto abort;
203 	}
204 	t1 |= t2 & 0xe0;
205 	*temp = (s16)t1 / 32 * 125;
206 abort:
207 	mutex_unlock(&data->access_lock);
208 	return err;
209 }
210 
211 static int nct7802_read_fan(struct nct7802_data *data, u8 reg_fan)
212 {
213 	unsigned int f1, f2;
214 	int ret;
215 
216 	mutex_lock(&data->access_lock);
217 	ret = regmap_read(data->regmap, reg_fan, &f1);
218 	if (ret < 0)
219 		goto abort;
220 	ret = regmap_read(data->regmap, REG_FANCOUNT_LOW, &f2);
221 	if (ret < 0)
222 		goto abort;
223 	ret = (f1 << 5) | (f2 >> 3);
224 	/* convert fan count to rpm */
225 	if (ret == 0x1fff)	/* maximum value, assume fan is stopped */
226 		ret = 0;
227 	else if (ret)
228 		ret = DIV_ROUND_CLOSEST(1350000U, ret);
229 abort:
230 	mutex_unlock(&data->access_lock);
231 	return ret;
232 }
233 
234 static int nct7802_read_fan_min(struct nct7802_data *data, u8 reg_fan_low,
235 				u8 reg_fan_high)
236 {
237 	unsigned int f1, f2;
238 	int ret;
239 
240 	mutex_lock(&data->access_lock);
241 	ret = regmap_read(data->regmap, reg_fan_low, &f1);
242 	if (ret < 0)
243 		goto abort;
244 	ret = regmap_read(data->regmap, reg_fan_high, &f2);
245 	if (ret < 0)
246 		goto abort;
247 	ret = f1 | ((f2 & 0xf8) << 5);
248 	/* convert fan count to rpm */
249 	if (ret == 0x1fff)	/* maximum value, assume no limit */
250 		ret = 0;
251 	else if (ret)
252 		ret = DIV_ROUND_CLOSEST(1350000U, ret);
253 	else
254 		ret = 1350000U;
255 abort:
256 	mutex_unlock(&data->access_lock);
257 	return ret;
258 }
259 
260 static int nct7802_write_fan_min(struct nct7802_data *data, u8 reg_fan_low,
261 				 u8 reg_fan_high, unsigned long limit)
262 {
263 	int err;
264 
265 	if (limit)
266 		limit = DIV_ROUND_CLOSEST(1350000U, limit);
267 	else
268 		limit = 0x1fff;
269 	limit = clamp_val(limit, 0, 0x1fff);
270 
271 	mutex_lock(&data->access_lock);
272 	err = regmap_write(data->regmap, reg_fan_low, limit & 0xff);
273 	if (err < 0)
274 		goto abort;
275 
276 	err = regmap_write(data->regmap, reg_fan_high, (limit & 0x1f00) >> 5);
277 abort:
278 	mutex_unlock(&data->access_lock);
279 	return err;
280 }
281 
282 static u8 nct7802_vmul[] = { 4, 2, 2, 2, 2 };
283 
284 static int nct7802_read_voltage(struct nct7802_data *data, int nr, int index)
285 {
286 	unsigned int v1, v2;
287 	int ret;
288 
289 	mutex_lock(&data->access_lock);
290 	if (index == 0) {	/* voltage */
291 		ret = regmap_read(data->regmap, REG_VOLTAGE[nr], &v1);
292 		if (ret < 0)
293 			goto abort;
294 		ret = regmap_read(data->regmap, REG_VOLTAGE_LOW, &v2);
295 		if (ret < 0)
296 			goto abort;
297 		ret = ((v1 << 2) | (v2 >> 6)) * nct7802_vmul[nr];
298 	}  else {	/* limit */
299 		int shift = 8 - REG_VOLTAGE_LIMIT_MSB_SHIFT[index - 1][nr];
300 
301 		ret = regmap_read(data->regmap,
302 				  REG_VOLTAGE_LIMIT_LSB[index - 1][nr], &v1);
303 		if (ret < 0)
304 			goto abort;
305 		ret = regmap_read(data->regmap, REG_VOLTAGE_LIMIT_MSB[nr],
306 				  &v2);
307 		if (ret < 0)
308 			goto abort;
309 		ret = (v1 | ((v2 << shift) & 0x300)) * nct7802_vmul[nr];
310 	}
311 abort:
312 	mutex_unlock(&data->access_lock);
313 	return ret;
314 }
315 
316 static int nct7802_write_voltage(struct nct7802_data *data, int nr, int index,
317 				 unsigned long voltage)
318 {
319 	int shift = 8 - REG_VOLTAGE_LIMIT_MSB_SHIFT[index - 1][nr];
320 	int err;
321 
322 	voltage = clamp_val(voltage, 0, 0x3ff * nct7802_vmul[nr]);
323 	voltage = DIV_ROUND_CLOSEST(voltage, nct7802_vmul[nr]);
324 
325 	mutex_lock(&data->access_lock);
326 	err = regmap_write(data->regmap,
327 			   REG_VOLTAGE_LIMIT_LSB[index - 1][nr],
328 			   voltage & 0xff);
329 	if (err < 0)
330 		goto abort;
331 
332 	err = regmap_update_bits(data->regmap, REG_VOLTAGE_LIMIT_MSB[nr],
333 				 0x0300 >> shift, (voltage & 0x0300) >> shift);
334 abort:
335 	mutex_unlock(&data->access_lock);
336 	return err;
337 }
338 
339 static ssize_t in_show(struct device *dev, struct device_attribute *attr,
340 		       char *buf)
341 {
342 	struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
343 	struct nct7802_data *data = dev_get_drvdata(dev);
344 	int voltage;
345 
346 	voltage = nct7802_read_voltage(data, sattr->nr, sattr->index);
347 	if (voltage < 0)
348 		return voltage;
349 
350 	return sprintf(buf, "%d\n", voltage);
351 }
352 
353 static ssize_t in_store(struct device *dev, struct device_attribute *attr,
354 			const char *buf, size_t count)
355 {
356 	struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
357 	struct nct7802_data *data = dev_get_drvdata(dev);
358 	int index = sattr->index;
359 	int nr = sattr->nr;
360 	unsigned long val;
361 	int err;
362 
363 	err = kstrtoul(buf, 10, &val);
364 	if (err < 0)
365 		return err;
366 
367 	err = nct7802_write_voltage(data, nr, index, val);
368 	return err ? : count;
369 }
370 
371 static ssize_t temp_show(struct device *dev, struct device_attribute *attr,
372 			 char *buf)
373 {
374 	struct nct7802_data *data = dev_get_drvdata(dev);
375 	struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
376 	int err, temp;
377 
378 	err = nct7802_read_temp(data, sattr->nr, sattr->index, &temp);
379 	if (err < 0)
380 		return err;
381 
382 	return sprintf(buf, "%d\n", temp);
383 }
384 
385 static ssize_t temp_store(struct device *dev, struct device_attribute *attr,
386 			  const char *buf, size_t count)
387 {
388 	struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
389 	struct nct7802_data *data = dev_get_drvdata(dev);
390 	int nr = sattr->nr;
391 	long val;
392 	int err;
393 
394 	err = kstrtol(buf, 10, &val);
395 	if (err < 0)
396 		return err;
397 
398 	val = DIV_ROUND_CLOSEST(clamp_val(val, -128000, 127000), 1000);
399 
400 	err = regmap_write(data->regmap, nr, val & 0xff);
401 	return err ? : count;
402 }
403 
404 static ssize_t fan_show(struct device *dev, struct device_attribute *attr,
405 			char *buf)
406 {
407 	struct sensor_device_attribute *sattr = to_sensor_dev_attr(attr);
408 	struct nct7802_data *data = dev_get_drvdata(dev);
409 	int speed;
410 
411 	speed = nct7802_read_fan(data, sattr->index);
412 	if (speed < 0)
413 		return speed;
414 
415 	return sprintf(buf, "%d\n", speed);
416 }
417 
418 static ssize_t fan_min_show(struct device *dev, struct device_attribute *attr,
419 			    char *buf)
420 {
421 	struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
422 	struct nct7802_data *data = dev_get_drvdata(dev);
423 	int speed;
424 
425 	speed = nct7802_read_fan_min(data, sattr->nr, sattr->index);
426 	if (speed < 0)
427 		return speed;
428 
429 	return sprintf(buf, "%d\n", speed);
430 }
431 
432 static ssize_t fan_min_store(struct device *dev,
433 			     struct device_attribute *attr, const char *buf,
434 			     size_t count)
435 {
436 	struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
437 	struct nct7802_data *data = dev_get_drvdata(dev);
438 	unsigned long val;
439 	int err;
440 
441 	err = kstrtoul(buf, 10, &val);
442 	if (err < 0)
443 		return err;
444 
445 	err = nct7802_write_fan_min(data, sattr->nr, sattr->index, val);
446 	return err ? : count;
447 }
448 
449 static ssize_t alarm_show(struct device *dev, struct device_attribute *attr,
450 			  char *buf)
451 {
452 	struct nct7802_data *data = dev_get_drvdata(dev);
453 	struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
454 	int bit = sattr->index;
455 	unsigned int val;
456 	int ret;
457 
458 	ret = regmap_read(data->regmap, sattr->nr, &val);
459 	if (ret < 0)
460 		return ret;
461 
462 	return sprintf(buf, "%u\n", !!(val & (1 << bit)));
463 }
464 
465 static ssize_t
466 beep_show(struct device *dev, struct device_attribute *attr, char *buf)
467 {
468 	struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
469 	struct nct7802_data *data = dev_get_drvdata(dev);
470 	unsigned int regval;
471 	int err;
472 
473 	err = regmap_read(data->regmap, sattr->nr, &regval);
474 	if (err)
475 		return err;
476 
477 	return sprintf(buf, "%u\n", !!(regval & (1 << sattr->index)));
478 }
479 
480 static ssize_t
481 beep_store(struct device *dev, struct device_attribute *attr, const char *buf,
482 	   size_t count)
483 {
484 	struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
485 	struct nct7802_data *data = dev_get_drvdata(dev);
486 	unsigned long val;
487 	int err;
488 
489 	err = kstrtoul(buf, 10, &val);
490 	if (err < 0)
491 		return err;
492 	if (val > 1)
493 		return -EINVAL;
494 
495 	err = regmap_update_bits(data->regmap, sattr->nr, 1 << sattr->index,
496 				 val ? 1 << sattr->index : 0);
497 	return err ? : count;
498 }
499 
500 static SENSOR_DEVICE_ATTR_RW(temp1_type, temp_type, 0);
501 static SENSOR_DEVICE_ATTR_2_RO(temp1_input, temp, 0x01, REG_TEMP_LSB);
502 static SENSOR_DEVICE_ATTR_2_RW(temp1_min, temp, 0x31, 0);
503 static SENSOR_DEVICE_ATTR_2_RW(temp1_max, temp, 0x30, 0);
504 static SENSOR_DEVICE_ATTR_2_RW(temp1_crit, temp, 0x3a, 0);
505 
506 static SENSOR_DEVICE_ATTR_RW(temp2_type, temp_type, 1);
507 static SENSOR_DEVICE_ATTR_2_RO(temp2_input, temp, 0x02, REG_TEMP_LSB);
508 static SENSOR_DEVICE_ATTR_2_RW(temp2_min, temp, 0x33, 0);
509 static SENSOR_DEVICE_ATTR_2_RW(temp2_max, temp, 0x32, 0);
510 static SENSOR_DEVICE_ATTR_2_RW(temp2_crit, temp, 0x3b, 0);
511 
512 static SENSOR_DEVICE_ATTR_RW(temp3_type, temp_type, 2);
513 static SENSOR_DEVICE_ATTR_2_RO(temp3_input, temp, 0x03, REG_TEMP_LSB);
514 static SENSOR_DEVICE_ATTR_2_RW(temp3_min, temp, 0x35, 0);
515 static SENSOR_DEVICE_ATTR_2_RW(temp3_max, temp, 0x34, 0);
516 static SENSOR_DEVICE_ATTR_2_RW(temp3_crit, temp, 0x3c, 0);
517 
518 static SENSOR_DEVICE_ATTR_2_RO(temp4_input, temp, 0x04, 0);
519 static SENSOR_DEVICE_ATTR_2_RW(temp4_min, temp, 0x37, 0);
520 static SENSOR_DEVICE_ATTR_2_RW(temp4_max, temp, 0x36, 0);
521 static SENSOR_DEVICE_ATTR_2_RW(temp4_crit, temp, 0x3d, 0);
522 
523 static SENSOR_DEVICE_ATTR_2_RO(temp5_input, temp, 0x06, REG_TEMP_PECI_LSB);
524 static SENSOR_DEVICE_ATTR_2_RW(temp5_min, temp, 0x39, 0);
525 static SENSOR_DEVICE_ATTR_2_RW(temp5_max, temp, 0x38, 0);
526 static SENSOR_DEVICE_ATTR_2_RW(temp5_crit, temp, 0x3e, 0);
527 
528 static SENSOR_DEVICE_ATTR_2_RO(temp6_input, temp, 0x07, REG_TEMP_PECI_LSB);
529 
530 static SENSOR_DEVICE_ATTR_2_RO(temp1_min_alarm, alarm, 0x18, 0);
531 static SENSOR_DEVICE_ATTR_2_RO(temp2_min_alarm, alarm, 0x18, 1);
532 static SENSOR_DEVICE_ATTR_2_RO(temp3_min_alarm, alarm, 0x18, 2);
533 static SENSOR_DEVICE_ATTR_2_RO(temp4_min_alarm, alarm, 0x18, 3);
534 static SENSOR_DEVICE_ATTR_2_RO(temp5_min_alarm, alarm, 0x18, 4);
535 
536 static SENSOR_DEVICE_ATTR_2_RO(temp1_max_alarm, alarm, 0x19, 0);
537 static SENSOR_DEVICE_ATTR_2_RO(temp2_max_alarm, alarm, 0x19, 1);
538 static SENSOR_DEVICE_ATTR_2_RO(temp3_max_alarm, alarm, 0x19, 2);
539 static SENSOR_DEVICE_ATTR_2_RO(temp4_max_alarm, alarm, 0x19, 3);
540 static SENSOR_DEVICE_ATTR_2_RO(temp5_max_alarm, alarm, 0x19, 4);
541 
542 static SENSOR_DEVICE_ATTR_2_RO(temp1_crit_alarm, alarm, 0x1b, 0);
543 static SENSOR_DEVICE_ATTR_2_RO(temp2_crit_alarm, alarm, 0x1b, 1);
544 static SENSOR_DEVICE_ATTR_2_RO(temp3_crit_alarm, alarm, 0x1b, 2);
545 static SENSOR_DEVICE_ATTR_2_RO(temp4_crit_alarm, alarm, 0x1b, 3);
546 static SENSOR_DEVICE_ATTR_2_RO(temp5_crit_alarm, alarm, 0x1b, 4);
547 
548 static SENSOR_DEVICE_ATTR_2_RO(temp1_fault, alarm, 0x17, 0);
549 static SENSOR_DEVICE_ATTR_2_RO(temp2_fault, alarm, 0x17, 1);
550 static SENSOR_DEVICE_ATTR_2_RO(temp3_fault, alarm, 0x17, 2);
551 
552 static SENSOR_DEVICE_ATTR_2_RW(temp1_beep, beep, 0x5c, 0);
553 static SENSOR_DEVICE_ATTR_2_RW(temp2_beep, beep, 0x5c, 1);
554 static SENSOR_DEVICE_ATTR_2_RW(temp3_beep, beep, 0x5c, 2);
555 static SENSOR_DEVICE_ATTR_2_RW(temp4_beep, beep, 0x5c, 3);
556 static SENSOR_DEVICE_ATTR_2_RW(temp5_beep, beep, 0x5c, 4);
557 static SENSOR_DEVICE_ATTR_2_RW(temp6_beep, beep, 0x5c, 5);
558 
559 static struct attribute *nct7802_temp_attrs[] = {
560 	&sensor_dev_attr_temp1_type.dev_attr.attr,
561 	&sensor_dev_attr_temp1_input.dev_attr.attr,
562 	&sensor_dev_attr_temp1_min.dev_attr.attr,
563 	&sensor_dev_attr_temp1_max.dev_attr.attr,
564 	&sensor_dev_attr_temp1_crit.dev_attr.attr,
565 	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
566 	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
567 	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
568 	&sensor_dev_attr_temp1_fault.dev_attr.attr,
569 	&sensor_dev_attr_temp1_beep.dev_attr.attr,
570 
571 	&sensor_dev_attr_temp2_type.dev_attr.attr,		/* 10 */
572 	&sensor_dev_attr_temp2_input.dev_attr.attr,
573 	&sensor_dev_attr_temp2_min.dev_attr.attr,
574 	&sensor_dev_attr_temp2_max.dev_attr.attr,
575 	&sensor_dev_attr_temp2_crit.dev_attr.attr,
576 	&sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
577 	&sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
578 	&sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
579 	&sensor_dev_attr_temp2_fault.dev_attr.attr,
580 	&sensor_dev_attr_temp2_beep.dev_attr.attr,
581 
582 	&sensor_dev_attr_temp3_type.dev_attr.attr,		/* 20 */
583 	&sensor_dev_attr_temp3_input.dev_attr.attr,
584 	&sensor_dev_attr_temp3_min.dev_attr.attr,
585 	&sensor_dev_attr_temp3_max.dev_attr.attr,
586 	&sensor_dev_attr_temp3_crit.dev_attr.attr,
587 	&sensor_dev_attr_temp3_min_alarm.dev_attr.attr,
588 	&sensor_dev_attr_temp3_max_alarm.dev_attr.attr,
589 	&sensor_dev_attr_temp3_crit_alarm.dev_attr.attr,
590 	&sensor_dev_attr_temp3_fault.dev_attr.attr,
591 	&sensor_dev_attr_temp3_beep.dev_attr.attr,
592 
593 	&sensor_dev_attr_temp4_input.dev_attr.attr,		/* 30 */
594 	&sensor_dev_attr_temp4_min.dev_attr.attr,
595 	&sensor_dev_attr_temp4_max.dev_attr.attr,
596 	&sensor_dev_attr_temp4_crit.dev_attr.attr,
597 	&sensor_dev_attr_temp4_min_alarm.dev_attr.attr,
598 	&sensor_dev_attr_temp4_max_alarm.dev_attr.attr,
599 	&sensor_dev_attr_temp4_crit_alarm.dev_attr.attr,
600 	&sensor_dev_attr_temp4_beep.dev_attr.attr,
601 
602 	&sensor_dev_attr_temp5_input.dev_attr.attr,		/* 38 */
603 	&sensor_dev_attr_temp5_min.dev_attr.attr,
604 	&sensor_dev_attr_temp5_max.dev_attr.attr,
605 	&sensor_dev_attr_temp5_crit.dev_attr.attr,
606 	&sensor_dev_attr_temp5_min_alarm.dev_attr.attr,
607 	&sensor_dev_attr_temp5_max_alarm.dev_attr.attr,
608 	&sensor_dev_attr_temp5_crit_alarm.dev_attr.attr,
609 	&sensor_dev_attr_temp5_beep.dev_attr.attr,
610 
611 	&sensor_dev_attr_temp6_input.dev_attr.attr,		/* 46 */
612 	&sensor_dev_attr_temp6_beep.dev_attr.attr,
613 
614 	NULL
615 };
616 
617 static umode_t nct7802_temp_is_visible(struct kobject *kobj,
618 				       struct attribute *attr, int index)
619 {
620 	struct device *dev = container_of(kobj, struct device, kobj);
621 	struct nct7802_data *data = dev_get_drvdata(dev);
622 	unsigned int reg;
623 	int err;
624 
625 	err = regmap_read(data->regmap, REG_MODE, &reg);
626 	if (err < 0)
627 		return 0;
628 
629 	if (index < 10 &&
630 	    (reg & 03) != 0x01 && (reg & 0x03) != 0x02)		/* RD1 */
631 		return 0;
632 
633 	if (index >= 10 && index < 20 &&
634 	    (reg & 0x0c) != 0x04 && (reg & 0x0c) != 0x08)	/* RD2 */
635 		return 0;
636 	if (index >= 20 && index < 30 && (reg & 0x30) != 0x20)	/* RD3 */
637 		return 0;
638 
639 	if (index >= 30 && index < 38)				/* local */
640 		return attr->mode;
641 
642 	err = regmap_read(data->regmap, REG_PECI_ENABLE, &reg);
643 	if (err < 0)
644 		return 0;
645 
646 	if (index >= 38 && index < 46 && !(reg & 0x01))		/* PECI 0 */
647 		return 0;
648 
649 	if (index >= 0x46 && (!(reg & 0x02)))			/* PECI 1 */
650 		return 0;
651 
652 	return attr->mode;
653 }
654 
655 static const struct attribute_group nct7802_temp_group = {
656 	.attrs = nct7802_temp_attrs,
657 	.is_visible = nct7802_temp_is_visible,
658 };
659 
660 static SENSOR_DEVICE_ATTR_2_RO(in0_input, in, 0, 0);
661 static SENSOR_DEVICE_ATTR_2_RW(in0_min, in, 0, 1);
662 static SENSOR_DEVICE_ATTR_2_RW(in0_max, in, 0, 2);
663 static SENSOR_DEVICE_ATTR_2_RO(in0_alarm, alarm, 0x1e, 3);
664 static SENSOR_DEVICE_ATTR_2_RW(in0_beep, beep, 0x5a, 3);
665 
666 static SENSOR_DEVICE_ATTR_2_RO(in1_input, in, 1, 0);
667 
668 static SENSOR_DEVICE_ATTR_2_RO(in2_input, in, 2, 0);
669 static SENSOR_DEVICE_ATTR_2_RW(in2_min, in, 2, 1);
670 static SENSOR_DEVICE_ATTR_2_RW(in2_max, in, 2, 2);
671 static SENSOR_DEVICE_ATTR_2_RO(in2_alarm, alarm, 0x1e, 0);
672 static SENSOR_DEVICE_ATTR_2_RW(in2_beep, beep, 0x5a, 0);
673 
674 static SENSOR_DEVICE_ATTR_2_RO(in3_input, in, 3, 0);
675 static SENSOR_DEVICE_ATTR_2_RW(in3_min, in, 3, 1);
676 static SENSOR_DEVICE_ATTR_2_RW(in3_max, in, 3, 2);
677 static SENSOR_DEVICE_ATTR_2_RO(in3_alarm, alarm, 0x1e, 1);
678 static SENSOR_DEVICE_ATTR_2_RW(in3_beep, beep, 0x5a, 1);
679 
680 static SENSOR_DEVICE_ATTR_2_RO(in4_input, in, 4, 0);
681 static SENSOR_DEVICE_ATTR_2_RW(in4_min, in, 4, 1);
682 static SENSOR_DEVICE_ATTR_2_RW(in4_max, in, 4, 2);
683 static SENSOR_DEVICE_ATTR_2_RO(in4_alarm, alarm, 0x1e, 2);
684 static SENSOR_DEVICE_ATTR_2_RW(in4_beep, beep, 0x5a, 2);
685 
686 static struct attribute *nct7802_in_attrs[] = {
687 	&sensor_dev_attr_in0_input.dev_attr.attr,
688 	&sensor_dev_attr_in0_min.dev_attr.attr,
689 	&sensor_dev_attr_in0_max.dev_attr.attr,
690 	&sensor_dev_attr_in0_alarm.dev_attr.attr,
691 	&sensor_dev_attr_in0_beep.dev_attr.attr,
692 
693 	&sensor_dev_attr_in1_input.dev_attr.attr,	/* 5 */
694 
695 	&sensor_dev_attr_in2_input.dev_attr.attr,	/* 6 */
696 	&sensor_dev_attr_in2_min.dev_attr.attr,
697 	&sensor_dev_attr_in2_max.dev_attr.attr,
698 	&sensor_dev_attr_in2_alarm.dev_attr.attr,
699 	&sensor_dev_attr_in2_beep.dev_attr.attr,
700 
701 	&sensor_dev_attr_in3_input.dev_attr.attr,	/* 11 */
702 	&sensor_dev_attr_in3_min.dev_attr.attr,
703 	&sensor_dev_attr_in3_max.dev_attr.attr,
704 	&sensor_dev_attr_in3_alarm.dev_attr.attr,
705 	&sensor_dev_attr_in3_beep.dev_attr.attr,
706 
707 	&sensor_dev_attr_in4_input.dev_attr.attr,	/* 17 */
708 	&sensor_dev_attr_in4_min.dev_attr.attr,
709 	&sensor_dev_attr_in4_max.dev_attr.attr,
710 	&sensor_dev_attr_in4_alarm.dev_attr.attr,
711 	&sensor_dev_attr_in4_beep.dev_attr.attr,
712 
713 	NULL,
714 };
715 
716 static umode_t nct7802_in_is_visible(struct kobject *kobj,
717 				     struct attribute *attr, int index)
718 {
719 	struct device *dev = container_of(kobj, struct device, kobj);
720 	struct nct7802_data *data = dev_get_drvdata(dev);
721 	unsigned int reg;
722 	int err;
723 
724 	if (index < 6)						/* VCC, VCORE */
725 		return attr->mode;
726 
727 	err = regmap_read(data->regmap, REG_MODE, &reg);
728 	if (err < 0)
729 		return 0;
730 
731 	if (index >= 6 && index < 11 && (reg & 0x03) != 0x03)	/* VSEN1 */
732 		return 0;
733 	if (index >= 11 && index < 17 && (reg & 0x0c) != 0x0c)	/* VSEN2 */
734 		return 0;
735 	if (index >= 17 && (reg & 0x30) != 0x30)		/* VSEN3 */
736 		return 0;
737 
738 	return attr->mode;
739 }
740 
741 static const struct attribute_group nct7802_in_group = {
742 	.attrs = nct7802_in_attrs,
743 	.is_visible = nct7802_in_is_visible,
744 };
745 
746 static SENSOR_DEVICE_ATTR_RO(fan1_input, fan, 0x10);
747 static SENSOR_DEVICE_ATTR_2_RW(fan1_min, fan_min, 0x49, 0x4c);
748 static SENSOR_DEVICE_ATTR_2_RO(fan1_alarm, alarm, 0x1a, 0);
749 static SENSOR_DEVICE_ATTR_2_RW(fan1_beep, beep, 0x5b, 0);
750 static SENSOR_DEVICE_ATTR_RO(fan2_input, fan, 0x11);
751 static SENSOR_DEVICE_ATTR_2_RW(fan2_min, fan_min, 0x4a, 0x4d);
752 static SENSOR_DEVICE_ATTR_2_RO(fan2_alarm, alarm, 0x1a, 1);
753 static SENSOR_DEVICE_ATTR_2_RW(fan2_beep, beep, 0x5b, 1);
754 static SENSOR_DEVICE_ATTR_RO(fan3_input, fan, 0x12);
755 static SENSOR_DEVICE_ATTR_2_RW(fan3_min, fan_min, 0x4b, 0x4e);
756 static SENSOR_DEVICE_ATTR_2_RO(fan3_alarm, alarm, 0x1a, 2);
757 static SENSOR_DEVICE_ATTR_2_RW(fan3_beep, beep, 0x5b, 2);
758 
759 /* 7.2.89 Fan Control Output Type */
760 static SENSOR_DEVICE_ATTR_RO(pwm1_mode, pwm_mode, 0);
761 static SENSOR_DEVICE_ATTR_RO(pwm2_mode, pwm_mode, 1);
762 static SENSOR_DEVICE_ATTR_RO(pwm3_mode, pwm_mode, 2);
763 
764 /* 7.2.91... Fan Control Output Value */
765 static SENSOR_DEVICE_ATTR_RW(pwm1, pwm, REG_PWM(0));
766 static SENSOR_DEVICE_ATTR_RW(pwm2, pwm, REG_PWM(1));
767 static SENSOR_DEVICE_ATTR_RW(pwm3, pwm, REG_PWM(2));
768 
769 /* 7.2.95... Temperature to Fan mapping Relationships Register */
770 static SENSOR_DEVICE_ATTR_RW(pwm1_enable, pwm_enable, 0);
771 static SENSOR_DEVICE_ATTR_RW(pwm2_enable, pwm_enable, 1);
772 static SENSOR_DEVICE_ATTR_RW(pwm3_enable, pwm_enable, 2);
773 
774 static struct attribute *nct7802_fan_attrs[] = {
775 	&sensor_dev_attr_fan1_input.dev_attr.attr,
776 	&sensor_dev_attr_fan1_min.dev_attr.attr,
777 	&sensor_dev_attr_fan1_alarm.dev_attr.attr,
778 	&sensor_dev_attr_fan1_beep.dev_attr.attr,
779 	&sensor_dev_attr_fan2_input.dev_attr.attr,
780 	&sensor_dev_attr_fan2_min.dev_attr.attr,
781 	&sensor_dev_attr_fan2_alarm.dev_attr.attr,
782 	&sensor_dev_attr_fan2_beep.dev_attr.attr,
783 	&sensor_dev_attr_fan3_input.dev_attr.attr,
784 	&sensor_dev_attr_fan3_min.dev_attr.attr,
785 	&sensor_dev_attr_fan3_alarm.dev_attr.attr,
786 	&sensor_dev_attr_fan3_beep.dev_attr.attr,
787 
788 	NULL
789 };
790 
791 static umode_t nct7802_fan_is_visible(struct kobject *kobj,
792 				      struct attribute *attr, int index)
793 {
794 	struct device *dev = container_of(kobj, struct device, kobj);
795 	struct nct7802_data *data = dev_get_drvdata(dev);
796 	int fan = index / 4;	/* 4 attributes per fan */
797 	unsigned int reg;
798 	int err;
799 
800 	err = regmap_read(data->regmap, REG_FAN_ENABLE, &reg);
801 	if (err < 0 || !(reg & (1 << fan)))
802 		return 0;
803 
804 	return attr->mode;
805 }
806 
807 static const struct attribute_group nct7802_fan_group = {
808 	.attrs = nct7802_fan_attrs,
809 	.is_visible = nct7802_fan_is_visible,
810 };
811 
812 static struct attribute *nct7802_pwm_attrs[] = {
813 	&sensor_dev_attr_pwm1_enable.dev_attr.attr,
814 	&sensor_dev_attr_pwm1_mode.dev_attr.attr,
815 	&sensor_dev_attr_pwm1.dev_attr.attr,
816 	&sensor_dev_attr_pwm2_enable.dev_attr.attr,
817 	&sensor_dev_attr_pwm2_mode.dev_attr.attr,
818 	&sensor_dev_attr_pwm2.dev_attr.attr,
819 	&sensor_dev_attr_pwm3_enable.dev_attr.attr,
820 	&sensor_dev_attr_pwm3_mode.dev_attr.attr,
821 	&sensor_dev_attr_pwm3.dev_attr.attr,
822 	NULL
823 };
824 
825 static const struct attribute_group nct7802_pwm_group = {
826 	.attrs = nct7802_pwm_attrs,
827 };
828 
829 /* 7.2.115... 0x80-0x83, 0x84 Temperature (X-axis) transition */
830 static SENSOR_DEVICE_ATTR_2_RW(pwm1_auto_point1_temp, temp, 0x80, 0);
831 static SENSOR_DEVICE_ATTR_2_RW(pwm1_auto_point2_temp, temp, 0x81, 0);
832 static SENSOR_DEVICE_ATTR_2_RW(pwm1_auto_point3_temp, temp, 0x82, 0);
833 static SENSOR_DEVICE_ATTR_2_RW(pwm1_auto_point4_temp, temp, 0x83, 0);
834 static SENSOR_DEVICE_ATTR_2_RW(pwm1_auto_point5_temp, temp, 0x84, 0);
835 
836 /* 7.2.120... 0x85-0x88 PWM (Y-axis) transition */
837 static SENSOR_DEVICE_ATTR_RW(pwm1_auto_point1_pwm, pwm, 0x85);
838 static SENSOR_DEVICE_ATTR_RW(pwm1_auto_point2_pwm, pwm, 0x86);
839 static SENSOR_DEVICE_ATTR_RW(pwm1_auto_point3_pwm, pwm, 0x87);
840 static SENSOR_DEVICE_ATTR_RW(pwm1_auto_point4_pwm, pwm, 0x88);
841 static SENSOR_DEVICE_ATTR_RO(pwm1_auto_point5_pwm, pwm, 0);
842 
843 /* 7.2.124 Table 2 X-axis Transition Point 1 Register */
844 static SENSOR_DEVICE_ATTR_2_RW(pwm2_auto_point1_temp, temp, 0x90, 0);
845 static SENSOR_DEVICE_ATTR_2_RW(pwm2_auto_point2_temp, temp, 0x91, 0);
846 static SENSOR_DEVICE_ATTR_2_RW(pwm2_auto_point3_temp, temp, 0x92, 0);
847 static SENSOR_DEVICE_ATTR_2_RW(pwm2_auto_point4_temp, temp, 0x93, 0);
848 static SENSOR_DEVICE_ATTR_2_RW(pwm2_auto_point5_temp, temp, 0x94, 0);
849 
850 /* 7.2.129 Table 2 Y-axis Transition Point 1 Register */
851 static SENSOR_DEVICE_ATTR_RW(pwm2_auto_point1_pwm, pwm, 0x95);
852 static SENSOR_DEVICE_ATTR_RW(pwm2_auto_point2_pwm, pwm, 0x96);
853 static SENSOR_DEVICE_ATTR_RW(pwm2_auto_point3_pwm, pwm, 0x97);
854 static SENSOR_DEVICE_ATTR_RW(pwm2_auto_point4_pwm, pwm, 0x98);
855 static SENSOR_DEVICE_ATTR_RO(pwm2_auto_point5_pwm, pwm, 0);
856 
857 /* 7.2.133 Table 3 X-axis Transition Point 1 Register */
858 static SENSOR_DEVICE_ATTR_2_RW(pwm3_auto_point1_temp, temp, 0xA0, 0);
859 static SENSOR_DEVICE_ATTR_2_RW(pwm3_auto_point2_temp, temp, 0xA1, 0);
860 static SENSOR_DEVICE_ATTR_2_RW(pwm3_auto_point3_temp, temp, 0xA2, 0);
861 static SENSOR_DEVICE_ATTR_2_RW(pwm3_auto_point4_temp, temp, 0xA3, 0);
862 static SENSOR_DEVICE_ATTR_2_RW(pwm3_auto_point5_temp, temp, 0xA4, 0);
863 
864 /* 7.2.138 Table 3 Y-axis Transition Point 1 Register */
865 static SENSOR_DEVICE_ATTR_RW(pwm3_auto_point1_pwm, pwm, 0xA5);
866 static SENSOR_DEVICE_ATTR_RW(pwm3_auto_point2_pwm, pwm, 0xA6);
867 static SENSOR_DEVICE_ATTR_RW(pwm3_auto_point3_pwm, pwm, 0xA7);
868 static SENSOR_DEVICE_ATTR_RW(pwm3_auto_point4_pwm, pwm, 0xA8);
869 static SENSOR_DEVICE_ATTR_RO(pwm3_auto_point5_pwm, pwm, 0);
870 
871 static struct attribute *nct7802_auto_point_attrs[] = {
872 	&sensor_dev_attr_pwm1_auto_point1_temp.dev_attr.attr,
873 	&sensor_dev_attr_pwm1_auto_point2_temp.dev_attr.attr,
874 	&sensor_dev_attr_pwm1_auto_point3_temp.dev_attr.attr,
875 	&sensor_dev_attr_pwm1_auto_point4_temp.dev_attr.attr,
876 	&sensor_dev_attr_pwm1_auto_point5_temp.dev_attr.attr,
877 
878 	&sensor_dev_attr_pwm1_auto_point1_pwm.dev_attr.attr,
879 	&sensor_dev_attr_pwm1_auto_point2_pwm.dev_attr.attr,
880 	&sensor_dev_attr_pwm1_auto_point3_pwm.dev_attr.attr,
881 	&sensor_dev_attr_pwm1_auto_point4_pwm.dev_attr.attr,
882 	&sensor_dev_attr_pwm1_auto_point5_pwm.dev_attr.attr,
883 
884 	&sensor_dev_attr_pwm2_auto_point1_temp.dev_attr.attr,
885 	&sensor_dev_attr_pwm2_auto_point2_temp.dev_attr.attr,
886 	&sensor_dev_attr_pwm2_auto_point3_temp.dev_attr.attr,
887 	&sensor_dev_attr_pwm2_auto_point4_temp.dev_attr.attr,
888 	&sensor_dev_attr_pwm2_auto_point5_temp.dev_attr.attr,
889 
890 	&sensor_dev_attr_pwm2_auto_point1_pwm.dev_attr.attr,
891 	&sensor_dev_attr_pwm2_auto_point2_pwm.dev_attr.attr,
892 	&sensor_dev_attr_pwm2_auto_point3_pwm.dev_attr.attr,
893 	&sensor_dev_attr_pwm2_auto_point4_pwm.dev_attr.attr,
894 	&sensor_dev_attr_pwm2_auto_point5_pwm.dev_attr.attr,
895 
896 	&sensor_dev_attr_pwm3_auto_point1_temp.dev_attr.attr,
897 	&sensor_dev_attr_pwm3_auto_point2_temp.dev_attr.attr,
898 	&sensor_dev_attr_pwm3_auto_point3_temp.dev_attr.attr,
899 	&sensor_dev_attr_pwm3_auto_point4_temp.dev_attr.attr,
900 	&sensor_dev_attr_pwm3_auto_point5_temp.dev_attr.attr,
901 
902 	&sensor_dev_attr_pwm3_auto_point1_pwm.dev_attr.attr,
903 	&sensor_dev_attr_pwm3_auto_point2_pwm.dev_attr.attr,
904 	&sensor_dev_attr_pwm3_auto_point3_pwm.dev_attr.attr,
905 	&sensor_dev_attr_pwm3_auto_point4_pwm.dev_attr.attr,
906 	&sensor_dev_attr_pwm3_auto_point5_pwm.dev_attr.attr,
907 
908 	NULL
909 };
910 
911 static const struct attribute_group nct7802_auto_point_group = {
912 	.attrs = nct7802_auto_point_attrs,
913 };
914 
915 static const struct attribute_group *nct7802_groups[] = {
916 	&nct7802_temp_group,
917 	&nct7802_in_group,
918 	&nct7802_fan_group,
919 	&nct7802_pwm_group,
920 	&nct7802_auto_point_group,
921 	NULL
922 };
923 
924 static int nct7802_detect(struct i2c_client *client,
925 			  struct i2c_board_info *info)
926 {
927 	int reg;
928 
929 	/*
930 	 * Chip identification registers are only available in bank 0,
931 	 * so only attempt chip detection if bank 0 is selected
932 	 */
933 	reg = i2c_smbus_read_byte_data(client, REG_BANK);
934 	if (reg != 0x00)
935 		return -ENODEV;
936 
937 	reg = i2c_smbus_read_byte_data(client, REG_VENDOR_ID);
938 	if (reg != 0x50)
939 		return -ENODEV;
940 
941 	reg = i2c_smbus_read_byte_data(client, REG_CHIP_ID);
942 	if (reg != 0xc3)
943 		return -ENODEV;
944 
945 	reg = i2c_smbus_read_byte_data(client, REG_VERSION_ID);
946 	if (reg < 0 || (reg & 0xf0) != 0x20)
947 		return -ENODEV;
948 
949 	/* Also validate lower bits of voltage and temperature registers */
950 	reg = i2c_smbus_read_byte_data(client, REG_TEMP_LSB);
951 	if (reg < 0 || (reg & 0x1f))
952 		return -ENODEV;
953 
954 	reg = i2c_smbus_read_byte_data(client, REG_TEMP_PECI_LSB);
955 	if (reg < 0 || (reg & 0x3f))
956 		return -ENODEV;
957 
958 	reg = i2c_smbus_read_byte_data(client, REG_VOLTAGE_LOW);
959 	if (reg < 0 || (reg & 0x3f))
960 		return -ENODEV;
961 
962 	strlcpy(info->type, "nct7802", I2C_NAME_SIZE);
963 	return 0;
964 }
965 
966 static bool nct7802_regmap_is_volatile(struct device *dev, unsigned int reg)
967 {
968 	return (reg != REG_BANK && reg <= 0x20) ||
969 		(reg >= REG_PWM(0) && reg <= REG_PWM(2));
970 }
971 
972 static const struct regmap_config nct7802_regmap_config = {
973 	.reg_bits = 8,
974 	.val_bits = 8,
975 	.cache_type = REGCACHE_RBTREE,
976 	.volatile_reg = nct7802_regmap_is_volatile,
977 };
978 
979 static int nct7802_init_chip(struct nct7802_data *data)
980 {
981 	int err;
982 
983 	/* Enable ADC */
984 	err = regmap_update_bits(data->regmap, REG_START, 0x01, 0x01);
985 	if (err)
986 		return err;
987 
988 	/* Enable local temperature sensor */
989 	err = regmap_update_bits(data->regmap, REG_MODE, 0x40, 0x40);
990 	if (err)
991 		return err;
992 
993 	/* Enable Vcore and VCC voltage monitoring */
994 	return regmap_update_bits(data->regmap, REG_VMON_ENABLE, 0x03, 0x03);
995 }
996 
997 static int nct7802_probe(struct i2c_client *client,
998 			 const struct i2c_device_id *id)
999 {
1000 	struct device *dev = &client->dev;
1001 	struct nct7802_data *data;
1002 	struct device *hwmon_dev;
1003 	int ret;
1004 
1005 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
1006 	if (data == NULL)
1007 		return -ENOMEM;
1008 
1009 	data->regmap = devm_regmap_init_i2c(client, &nct7802_regmap_config);
1010 	if (IS_ERR(data->regmap))
1011 		return PTR_ERR(data->regmap);
1012 
1013 	mutex_init(&data->access_lock);
1014 
1015 	ret = nct7802_init_chip(data);
1016 	if (ret < 0)
1017 		return ret;
1018 
1019 	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
1020 							   data,
1021 							   nct7802_groups);
1022 	return PTR_ERR_OR_ZERO(hwmon_dev);
1023 }
1024 
1025 static const unsigned short nct7802_address_list[] = {
1026 	0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, I2C_CLIENT_END
1027 };
1028 
1029 static const struct i2c_device_id nct7802_idtable[] = {
1030 	{ "nct7802", 0 },
1031 	{ }
1032 };
1033 MODULE_DEVICE_TABLE(i2c, nct7802_idtable);
1034 
1035 static struct i2c_driver nct7802_driver = {
1036 	.class = I2C_CLASS_HWMON,
1037 	.driver = {
1038 		.name = DRVNAME,
1039 	},
1040 	.detect = nct7802_detect,
1041 	.probe = nct7802_probe,
1042 	.id_table = nct7802_idtable,
1043 	.address_list = nct7802_address_list,
1044 };
1045 
1046 module_i2c_driver(nct7802_driver);
1047 
1048 MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>");
1049 MODULE_DESCRIPTION("NCT7802Y Hardware Monitoring Driver");
1050 MODULE_LICENSE("GPL v2");
1051