xref: /linux/drivers/thermal/thermal_sysfs.c (revision b8e4b0529d59a3ccd0b25a31d3cfc8b0f3b34068)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  thermal.c - sysfs interface of thermal devices
4  *
5  *  Copyright (C) 2016 Eduardo Valentin <edubezval@gmail.com>
6  *
7  *  Highly based on original thermal_core.c
8  *  Copyright (C) 2008 Intel Corp
9  *  Copyright (C) 2008 Zhang Rui <rui.zhang@intel.com>
10  *  Copyright (C) 2008 Sujith Thomas <sujith.thomas@intel.com>
11  */
12 
13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14 
15 #include <linux/sysfs.h>
16 #include <linux/device.h>
17 #include <linux/err.h>
18 #include <linux/slab.h>
19 #include <linux/string.h>
20 #include <linux/jiffies.h>
21 
22 #include "thermal_core.h"
23 
24 /* sys I/F for thermal zone */
25 
26 static ssize_t
27 type_show(struct device *dev, struct device_attribute *attr, char *buf)
28 {
29 	struct thermal_zone_device *tz = to_thermal_zone(dev);
30 
31 	return sprintf(buf, "%s\n", tz->type);
32 }
33 
34 static ssize_t
35 temp_show(struct device *dev, struct device_attribute *attr, char *buf)
36 {
37 	struct thermal_zone_device *tz = to_thermal_zone(dev);
38 	int temperature, ret;
39 
40 	ret = thermal_zone_get_temp(tz, &temperature);
41 
42 	if (ret)
43 		return ret;
44 
45 	return sprintf(buf, "%d\n", temperature);
46 }
47 
48 static ssize_t
49 mode_show(struct device *dev, struct device_attribute *attr, char *buf)
50 {
51 	struct thermal_zone_device *tz = to_thermal_zone(dev);
52 	int enabled;
53 
54 	mutex_lock(&tz->lock);
55 	enabled = thermal_zone_device_is_enabled(tz);
56 	mutex_unlock(&tz->lock);
57 
58 	return sprintf(buf, "%s\n", enabled ? "enabled" : "disabled");
59 }
60 
61 static ssize_t
62 mode_store(struct device *dev, struct device_attribute *attr,
63 	   const char *buf, size_t count)
64 {
65 	struct thermal_zone_device *tz = to_thermal_zone(dev);
66 	int result;
67 
68 	if (!strncmp(buf, "enabled", sizeof("enabled") - 1))
69 		result = thermal_zone_device_enable(tz);
70 	else if (!strncmp(buf, "disabled", sizeof("disabled") - 1))
71 		result = thermal_zone_device_disable(tz);
72 	else
73 		result = -EINVAL;
74 
75 	if (result)
76 		return result;
77 
78 	return count;
79 }
80 
81 static ssize_t
82 trip_point_type_show(struct device *dev, struct device_attribute *attr,
83 		     char *buf)
84 {
85 	struct thermal_zone_device *tz = to_thermal_zone(dev);
86 	int trip_id;
87 
88 	if (sscanf(attr->attr.name, "trip_point_%d_type", &trip_id) != 1)
89 		return -EINVAL;
90 
91 	return sprintf(buf, "%s\n", thermal_trip_type_name(tz->trips[trip_id].trip.type));
92 }
93 
94 static ssize_t
95 trip_point_temp_store(struct device *dev, struct device_attribute *attr,
96 		      const char *buf, size_t count)
97 {
98 	struct thermal_zone_device *tz = to_thermal_zone(dev);
99 	struct thermal_trip *trip;
100 	int trip_id, ret;
101 	int temp;
102 
103 	ret = kstrtoint(buf, 10, &temp);
104 	if (ret)
105 		return -EINVAL;
106 
107 	if (sscanf(attr->attr.name, "trip_point_%d_temp", &trip_id) != 1)
108 		return -EINVAL;
109 
110 	mutex_lock(&tz->lock);
111 
112 	trip = &tz->trips[trip_id].trip;
113 
114 	if (temp != trip->temperature) {
115 		if (tz->ops.set_trip_temp) {
116 			ret = tz->ops.set_trip_temp(tz, trip, temp);
117 			if (ret)
118 				goto unlock;
119 		}
120 
121 		thermal_zone_set_trip_temp(tz, trip, temp);
122 
123 		__thermal_zone_device_update(tz, THERMAL_TRIP_CHANGED);
124 	}
125 
126 unlock:
127 	mutex_unlock(&tz->lock);
128 
129 	return ret ? ret : count;
130 }
131 
132 static ssize_t
133 trip_point_temp_show(struct device *dev, struct device_attribute *attr,
134 		     char *buf)
135 {
136 	struct thermal_zone_device *tz = to_thermal_zone(dev);
137 	int trip_id;
138 
139 	if (sscanf(attr->attr.name, "trip_point_%d_temp", &trip_id) != 1)
140 		return -EINVAL;
141 
142 	return sprintf(buf, "%d\n", READ_ONCE(tz->trips[trip_id].trip.temperature));
143 }
144 
145 static ssize_t
146 trip_point_hyst_store(struct device *dev, struct device_attribute *attr,
147 		      const char *buf, size_t count)
148 {
149 	struct thermal_zone_device *tz = to_thermal_zone(dev);
150 	struct thermal_trip *trip;
151 	int trip_id, ret;
152 	int hyst;
153 
154 	ret = kstrtoint(buf, 10, &hyst);
155 	if (ret || hyst < 0)
156 		return -EINVAL;
157 
158 	if (sscanf(attr->attr.name, "trip_point_%d_hyst", &trip_id) != 1)
159 		return -EINVAL;
160 
161 	mutex_lock(&tz->lock);
162 
163 	trip = &tz->trips[trip_id].trip;
164 
165 	if (hyst != trip->hysteresis) {
166 		WRITE_ONCE(trip->hysteresis, hyst);
167 
168 		thermal_zone_trip_updated(tz, trip);
169 	}
170 
171 	mutex_unlock(&tz->lock);
172 
173 	return count;
174 }
175 
176 static ssize_t
177 trip_point_hyst_show(struct device *dev, struct device_attribute *attr,
178 		     char *buf)
179 {
180 	struct thermal_zone_device *tz = to_thermal_zone(dev);
181 	int trip_id;
182 
183 	if (sscanf(attr->attr.name, "trip_point_%d_hyst", &trip_id) != 1)
184 		return -EINVAL;
185 
186 	return sprintf(buf, "%d\n", READ_ONCE(tz->trips[trip_id].trip.hysteresis));
187 }
188 
189 static ssize_t
190 policy_store(struct device *dev, struct device_attribute *attr,
191 	     const char *buf, size_t count)
192 {
193 	struct thermal_zone_device *tz = to_thermal_zone(dev);
194 	char name[THERMAL_NAME_LENGTH];
195 	int ret;
196 
197 	snprintf(name, sizeof(name), "%s", buf);
198 
199 	ret = thermal_zone_device_set_policy(tz, name);
200 	if (!ret)
201 		ret = count;
202 
203 	return ret;
204 }
205 
206 static ssize_t
207 policy_show(struct device *dev, struct device_attribute *devattr, char *buf)
208 {
209 	struct thermal_zone_device *tz = to_thermal_zone(dev);
210 
211 	return sprintf(buf, "%s\n", tz->governor->name);
212 }
213 
214 static ssize_t
215 available_policies_show(struct device *dev, struct device_attribute *devattr,
216 			char *buf)
217 {
218 	return thermal_build_list_of_policies(buf);
219 }
220 
221 #if (IS_ENABLED(CONFIG_THERMAL_EMULATION))
222 static ssize_t
223 emul_temp_store(struct device *dev, struct device_attribute *attr,
224 		const char *buf, size_t count)
225 {
226 	struct thermal_zone_device *tz = to_thermal_zone(dev);
227 	int ret = 0;
228 	int temperature;
229 
230 	if (kstrtoint(buf, 10, &temperature))
231 		return -EINVAL;
232 
233 	mutex_lock(&tz->lock);
234 
235 	if (!tz->ops.set_emul_temp)
236 		tz->emul_temperature = temperature;
237 	else
238 		ret = tz->ops.set_emul_temp(tz, temperature);
239 
240 	if (!ret)
241 		__thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
242 
243 	mutex_unlock(&tz->lock);
244 
245 	return ret ? ret : count;
246 }
247 static DEVICE_ATTR_WO(emul_temp);
248 #endif
249 
250 static ssize_t
251 sustainable_power_show(struct device *dev, struct device_attribute *devattr,
252 		       char *buf)
253 {
254 	struct thermal_zone_device *tz = to_thermal_zone(dev);
255 
256 	if (tz->tzp)
257 		return sprintf(buf, "%u\n", tz->tzp->sustainable_power);
258 	else
259 		return -EIO;
260 }
261 
262 static ssize_t
263 sustainable_power_store(struct device *dev, struct device_attribute *devattr,
264 			const char *buf, size_t count)
265 {
266 	struct thermal_zone_device *tz = to_thermal_zone(dev);
267 	u32 sustainable_power;
268 
269 	if (!tz->tzp)
270 		return -EIO;
271 
272 	if (kstrtou32(buf, 10, &sustainable_power))
273 		return -EINVAL;
274 
275 	tz->tzp->sustainable_power = sustainable_power;
276 
277 	return count;
278 }
279 
280 #define create_s32_tzp_attr(name)					\
281 	static ssize_t							\
282 	name##_show(struct device *dev, struct device_attribute *devattr, \
283 		char *buf)						\
284 	{								\
285 	struct thermal_zone_device *tz = to_thermal_zone(dev);		\
286 									\
287 	if (tz->tzp)							\
288 		return sprintf(buf, "%d\n", tz->tzp->name);		\
289 	else								\
290 		return -EIO;						\
291 	}								\
292 									\
293 	static ssize_t							\
294 	name##_store(struct device *dev, struct device_attribute *devattr, \
295 		const char *buf, size_t count)				\
296 	{								\
297 		struct thermal_zone_device *tz = to_thermal_zone(dev);	\
298 		s32 value;						\
299 									\
300 		if (!tz->tzp)						\
301 			return -EIO;					\
302 									\
303 		if (kstrtos32(buf, 10, &value))				\
304 			return -EINVAL;					\
305 									\
306 		tz->tzp->name = value;					\
307 									\
308 		return count;						\
309 	}								\
310 	static DEVICE_ATTR_RW(name)
311 
312 create_s32_tzp_attr(k_po);
313 create_s32_tzp_attr(k_pu);
314 create_s32_tzp_attr(k_i);
315 create_s32_tzp_attr(k_d);
316 create_s32_tzp_attr(integral_cutoff);
317 create_s32_tzp_attr(slope);
318 create_s32_tzp_attr(offset);
319 #undef create_s32_tzp_attr
320 
321 /*
322  * These are thermal zone device attributes that will always be present.
323  * All the attributes created for tzp (create_s32_tzp_attr) also are always
324  * present on the sysfs interface.
325  */
326 static DEVICE_ATTR_RO(type);
327 static DEVICE_ATTR_RO(temp);
328 static DEVICE_ATTR_RW(policy);
329 static DEVICE_ATTR_RO(available_policies);
330 static DEVICE_ATTR_RW(sustainable_power);
331 
332 /* These thermal zone device attributes are created based on conditions */
333 static DEVICE_ATTR_RW(mode);
334 
335 /* These attributes are unconditionally added to a thermal zone */
336 static struct attribute *thermal_zone_dev_attrs[] = {
337 	&dev_attr_type.attr,
338 	&dev_attr_temp.attr,
339 #if (IS_ENABLED(CONFIG_THERMAL_EMULATION))
340 	&dev_attr_emul_temp.attr,
341 #endif
342 	&dev_attr_policy.attr,
343 	&dev_attr_available_policies.attr,
344 	&dev_attr_sustainable_power.attr,
345 	&dev_attr_k_po.attr,
346 	&dev_attr_k_pu.attr,
347 	&dev_attr_k_i.attr,
348 	&dev_attr_k_d.attr,
349 	&dev_attr_integral_cutoff.attr,
350 	&dev_attr_slope.attr,
351 	&dev_attr_offset.attr,
352 	NULL,
353 };
354 
355 static const struct attribute_group thermal_zone_attribute_group = {
356 	.attrs = thermal_zone_dev_attrs,
357 };
358 
359 static struct attribute *thermal_zone_mode_attrs[] = {
360 	&dev_attr_mode.attr,
361 	NULL,
362 };
363 
364 static const struct attribute_group thermal_zone_mode_attribute_group = {
365 	.attrs = thermal_zone_mode_attrs,
366 };
367 
368 static const struct attribute_group *thermal_zone_attribute_groups[] = {
369 	&thermal_zone_attribute_group,
370 	&thermal_zone_mode_attribute_group,
371 	/* This is not NULL terminated as we create the group dynamically */
372 };
373 
374 /**
375  * create_trip_attrs() - create attributes for trip points
376  * @tz:		the thermal zone device
377  *
378  * helper function to instantiate sysfs entries for every trip
379  * point and its properties of a struct thermal_zone_device.
380  *
381  * Return: 0 on success, the proper error value otherwise.
382  */
383 static int create_trip_attrs(struct thermal_zone_device *tz)
384 {
385 	const struct thermal_trip_desc *td;
386 	struct attribute **attrs;
387 
388 	/* This function works only for zones with at least one trip */
389 	if (tz->num_trips <= 0)
390 		return -EINVAL;
391 
392 	tz->trip_type_attrs = kcalloc(tz->num_trips, sizeof(*tz->trip_type_attrs),
393 				      GFP_KERNEL);
394 	if (!tz->trip_type_attrs)
395 		return -ENOMEM;
396 
397 	tz->trip_temp_attrs = kcalloc(tz->num_trips, sizeof(*tz->trip_temp_attrs),
398 				      GFP_KERNEL);
399 	if (!tz->trip_temp_attrs) {
400 		kfree(tz->trip_type_attrs);
401 		return -ENOMEM;
402 	}
403 
404 	tz->trip_hyst_attrs = kcalloc(tz->num_trips,
405 				      sizeof(*tz->trip_hyst_attrs),
406 				      GFP_KERNEL);
407 	if (!tz->trip_hyst_attrs) {
408 		kfree(tz->trip_type_attrs);
409 		kfree(tz->trip_temp_attrs);
410 		return -ENOMEM;
411 	}
412 
413 	attrs = kcalloc(tz->num_trips * 3 + 1, sizeof(*attrs), GFP_KERNEL);
414 	if (!attrs) {
415 		kfree(tz->trip_type_attrs);
416 		kfree(tz->trip_temp_attrs);
417 		kfree(tz->trip_hyst_attrs);
418 		return -ENOMEM;
419 	}
420 
421 	for_each_trip_desc(tz, td) {
422 		int indx = thermal_zone_trip_id(tz, &td->trip);
423 
424 		/* create trip type attribute */
425 		snprintf(tz->trip_type_attrs[indx].name, THERMAL_NAME_LENGTH,
426 			 "trip_point_%d_type", indx);
427 
428 		sysfs_attr_init(&tz->trip_type_attrs[indx].attr.attr);
429 		tz->trip_type_attrs[indx].attr.attr.name =
430 						tz->trip_type_attrs[indx].name;
431 		tz->trip_type_attrs[indx].attr.attr.mode = S_IRUGO;
432 		tz->trip_type_attrs[indx].attr.show = trip_point_type_show;
433 		attrs[indx] = &tz->trip_type_attrs[indx].attr.attr;
434 
435 		/* create trip temp attribute */
436 		snprintf(tz->trip_temp_attrs[indx].name, THERMAL_NAME_LENGTH,
437 			 "trip_point_%d_temp", indx);
438 
439 		sysfs_attr_init(&tz->trip_temp_attrs[indx].attr.attr);
440 		tz->trip_temp_attrs[indx].attr.attr.name =
441 						tz->trip_temp_attrs[indx].name;
442 		tz->trip_temp_attrs[indx].attr.attr.mode = S_IRUGO;
443 		tz->trip_temp_attrs[indx].attr.show = trip_point_temp_show;
444 		if (td->trip.flags & THERMAL_TRIP_FLAG_RW_TEMP) {
445 			tz->trip_temp_attrs[indx].attr.attr.mode |= S_IWUSR;
446 			tz->trip_temp_attrs[indx].attr.store =
447 							trip_point_temp_store;
448 		}
449 		attrs[indx + tz->num_trips] = &tz->trip_temp_attrs[indx].attr.attr;
450 
451 		snprintf(tz->trip_hyst_attrs[indx].name, THERMAL_NAME_LENGTH,
452 			 "trip_point_%d_hyst", indx);
453 
454 		sysfs_attr_init(&tz->trip_hyst_attrs[indx].attr.attr);
455 		tz->trip_hyst_attrs[indx].attr.attr.name =
456 					tz->trip_hyst_attrs[indx].name;
457 		tz->trip_hyst_attrs[indx].attr.attr.mode = S_IRUGO;
458 		tz->trip_hyst_attrs[indx].attr.show = trip_point_hyst_show;
459 		if (td->trip.flags & THERMAL_TRIP_FLAG_RW_HYST) {
460 			tz->trip_hyst_attrs[indx].attr.attr.mode |= S_IWUSR;
461 			tz->trip_hyst_attrs[indx].attr.store =
462 					trip_point_hyst_store;
463 		}
464 		attrs[indx + tz->num_trips * 2] =
465 					&tz->trip_hyst_attrs[indx].attr.attr;
466 	}
467 	attrs[tz->num_trips * 3] = NULL;
468 
469 	tz->trips_attribute_group.attrs = attrs;
470 
471 	return 0;
472 }
473 
474 /**
475  * destroy_trip_attrs() - destroy attributes for trip points
476  * @tz:		the thermal zone device
477  *
478  * helper function to free resources allocated by create_trip_attrs()
479  */
480 static void destroy_trip_attrs(struct thermal_zone_device *tz)
481 {
482 	if (!tz)
483 		return;
484 
485 	kfree(tz->trip_type_attrs);
486 	kfree(tz->trip_temp_attrs);
487 	kfree(tz->trip_hyst_attrs);
488 	kfree(tz->trips_attribute_group.attrs);
489 }
490 
491 int thermal_zone_create_device_groups(struct thermal_zone_device *tz)
492 {
493 	const struct attribute_group **groups;
494 	int i, size, result;
495 
496 	/* we need one extra for trips and the NULL to terminate the array */
497 	size = ARRAY_SIZE(thermal_zone_attribute_groups) + 2;
498 	/* This also takes care of API requirement to be NULL terminated */
499 	groups = kcalloc(size, sizeof(*groups), GFP_KERNEL);
500 	if (!groups)
501 		return -ENOMEM;
502 
503 	for (i = 0; i < size - 2; i++)
504 		groups[i] = thermal_zone_attribute_groups[i];
505 
506 	if (tz->num_trips) {
507 		result = create_trip_attrs(tz);
508 		if (result) {
509 			kfree(groups);
510 
511 			return result;
512 		}
513 
514 		groups[size - 2] = &tz->trips_attribute_group;
515 	}
516 
517 	tz->device.groups = groups;
518 
519 	return 0;
520 }
521 
522 void thermal_zone_destroy_device_groups(struct thermal_zone_device *tz)
523 {
524 	if (!tz)
525 		return;
526 
527 	if (tz->num_trips)
528 		destroy_trip_attrs(tz);
529 
530 	kfree(tz->device.groups);
531 }
532 
533 /* sys I/F for cooling device */
534 static ssize_t
535 cdev_type_show(struct device *dev, struct device_attribute *attr, char *buf)
536 {
537 	struct thermal_cooling_device *cdev = to_cooling_device(dev);
538 
539 	return sprintf(buf, "%s\n", cdev->type);
540 }
541 
542 static ssize_t max_state_show(struct device *dev, struct device_attribute *attr,
543 			      char *buf)
544 {
545 	struct thermal_cooling_device *cdev = to_cooling_device(dev);
546 
547 	return sprintf(buf, "%ld\n", cdev->max_state);
548 }
549 
550 static ssize_t cur_state_show(struct device *dev, struct device_attribute *attr,
551 			      char *buf)
552 {
553 	struct thermal_cooling_device *cdev = to_cooling_device(dev);
554 	unsigned long state;
555 	int ret;
556 
557 	ret = cdev->ops->get_cur_state(cdev, &state);
558 	if (ret)
559 		return ret;
560 	return sprintf(buf, "%ld\n", state);
561 }
562 
563 static ssize_t
564 cur_state_store(struct device *dev, struct device_attribute *attr,
565 		const char *buf, size_t count)
566 {
567 	struct thermal_cooling_device *cdev = to_cooling_device(dev);
568 	unsigned long state;
569 	int result;
570 
571 	if (sscanf(buf, "%ld\n", &state) != 1)
572 		return -EINVAL;
573 
574 	if ((long)state < 0)
575 		return -EINVAL;
576 
577 	/* Requested state should be less than max_state + 1 */
578 	if (state > cdev->max_state)
579 		return -EINVAL;
580 
581 	mutex_lock(&cdev->lock);
582 
583 	result = cdev->ops->set_cur_state(cdev, state);
584 	if (!result)
585 		thermal_cooling_device_stats_update(cdev, state);
586 
587 	mutex_unlock(&cdev->lock);
588 	return result ? result : count;
589 }
590 
591 static struct device_attribute
592 dev_attr_cdev_type = __ATTR(type, 0444, cdev_type_show, NULL);
593 static DEVICE_ATTR_RO(max_state);
594 static DEVICE_ATTR_RW(cur_state);
595 
596 static struct attribute *cooling_device_attrs[] = {
597 	&dev_attr_cdev_type.attr,
598 	&dev_attr_max_state.attr,
599 	&dev_attr_cur_state.attr,
600 	NULL,
601 };
602 
603 static const struct attribute_group cooling_device_attr_group = {
604 	.attrs = cooling_device_attrs,
605 };
606 
607 static const struct attribute_group *cooling_device_attr_groups[] = {
608 	&cooling_device_attr_group,
609 	NULL, /* Space allocated for cooling_device_stats_attr_group */
610 	NULL,
611 };
612 
613 #ifdef CONFIG_THERMAL_STATISTICS
614 struct cooling_dev_stats {
615 	spinlock_t lock;
616 	unsigned int total_trans;
617 	unsigned long state;
618 	ktime_t last_time;
619 	ktime_t *time_in_state;
620 	unsigned int *trans_table;
621 };
622 
623 static void update_time_in_state(struct cooling_dev_stats *stats)
624 {
625 	ktime_t now = ktime_get(), delta;
626 
627 	delta = ktime_sub(now, stats->last_time);
628 	stats->time_in_state[stats->state] =
629 		ktime_add(stats->time_in_state[stats->state], delta);
630 	stats->last_time = now;
631 }
632 
633 void thermal_cooling_device_stats_update(struct thermal_cooling_device *cdev,
634 					 unsigned long new_state)
635 {
636 	struct cooling_dev_stats *stats = cdev->stats;
637 
638 	lockdep_assert_held(&cdev->lock);
639 
640 	if (!stats)
641 		return;
642 
643 	spin_lock(&stats->lock);
644 
645 	if (stats->state == new_state)
646 		goto unlock;
647 
648 	update_time_in_state(stats);
649 	stats->trans_table[stats->state * (cdev->max_state + 1) + new_state]++;
650 	stats->state = new_state;
651 	stats->total_trans++;
652 
653 unlock:
654 	spin_unlock(&stats->lock);
655 }
656 
657 static ssize_t total_trans_show(struct device *dev,
658 				struct device_attribute *attr, char *buf)
659 {
660 	struct thermal_cooling_device *cdev = to_cooling_device(dev);
661 	struct cooling_dev_stats *stats;
662 	int ret = 0;
663 
664 	mutex_lock(&cdev->lock);
665 
666 	stats = cdev->stats;
667 	if (!stats)
668 		goto unlock;
669 
670 	spin_lock(&stats->lock);
671 	ret = sprintf(buf, "%u\n", stats->total_trans);
672 	spin_unlock(&stats->lock);
673 
674 unlock:
675 	mutex_unlock(&cdev->lock);
676 
677 	return ret;
678 }
679 
680 static ssize_t
681 time_in_state_ms_show(struct device *dev, struct device_attribute *attr,
682 		      char *buf)
683 {
684 	struct thermal_cooling_device *cdev = to_cooling_device(dev);
685 	struct cooling_dev_stats *stats;
686 	ssize_t len = 0;
687 	int i;
688 
689 	mutex_lock(&cdev->lock);
690 
691 	stats = cdev->stats;
692 	if (!stats)
693 		goto unlock;
694 
695 	spin_lock(&stats->lock);
696 
697 	update_time_in_state(stats);
698 
699 	for (i = 0; i <= cdev->max_state; i++) {
700 		len += sprintf(buf + len, "state%u\t%llu\n", i,
701 			       ktime_to_ms(stats->time_in_state[i]));
702 	}
703 	spin_unlock(&stats->lock);
704 
705 unlock:
706 	mutex_unlock(&cdev->lock);
707 
708 	return len;
709 }
710 
711 static ssize_t
712 reset_store(struct device *dev, struct device_attribute *attr, const char *buf,
713 	    size_t count)
714 {
715 	struct thermal_cooling_device *cdev = to_cooling_device(dev);
716 	struct cooling_dev_stats *stats;
717 	int i, states;
718 
719 	mutex_lock(&cdev->lock);
720 
721 	stats = cdev->stats;
722 	if (!stats)
723 		goto unlock;
724 
725 	states = cdev->max_state + 1;
726 
727 	spin_lock(&stats->lock);
728 
729 	stats->total_trans = 0;
730 	stats->last_time = ktime_get();
731 	memset(stats->trans_table, 0,
732 	       states * states * sizeof(*stats->trans_table));
733 
734 	for (i = 0; i < states; i++)
735 		stats->time_in_state[i] = ktime_set(0, 0);
736 
737 	spin_unlock(&stats->lock);
738 
739 unlock:
740 	mutex_unlock(&cdev->lock);
741 
742 	return count;
743 }
744 
745 static ssize_t trans_table_show(struct device *dev,
746 				struct device_attribute *attr, char *buf)
747 {
748 	struct thermal_cooling_device *cdev = to_cooling_device(dev);
749 	struct cooling_dev_stats *stats;
750 	ssize_t len = 0;
751 	int i, j;
752 
753 	mutex_lock(&cdev->lock);
754 
755 	stats = cdev->stats;
756 	if (!stats) {
757 		len = -ENODATA;
758 		goto unlock;
759 	}
760 
761 	len += snprintf(buf + len, PAGE_SIZE - len, " From  :    To\n");
762 	len += snprintf(buf + len, PAGE_SIZE - len, "       : ");
763 	for (i = 0; i <= cdev->max_state; i++) {
764 		if (len >= PAGE_SIZE)
765 			break;
766 		len += snprintf(buf + len, PAGE_SIZE - len, "state%2u  ", i);
767 	}
768 	if (len >= PAGE_SIZE) {
769 		len = PAGE_SIZE;
770 		goto unlock;
771 	}
772 
773 	len += snprintf(buf + len, PAGE_SIZE - len, "\n");
774 
775 	for (i = 0; i <= cdev->max_state; i++) {
776 		if (len >= PAGE_SIZE)
777 			break;
778 
779 		len += snprintf(buf + len, PAGE_SIZE - len, "state%2u:", i);
780 
781 		for (j = 0; j <= cdev->max_state; j++) {
782 			if (len >= PAGE_SIZE)
783 				break;
784 			len += snprintf(buf + len, PAGE_SIZE - len, "%8u ",
785 				stats->trans_table[i * (cdev->max_state + 1) + j]);
786 		}
787 		if (len >= PAGE_SIZE)
788 			break;
789 		len += snprintf(buf + len, PAGE_SIZE - len, "\n");
790 	}
791 
792 	if (len >= PAGE_SIZE) {
793 		pr_warn_once("Thermal transition table exceeds PAGE_SIZE. Disabling\n");
794 		len = -EFBIG;
795 	}
796 
797 unlock:
798 	mutex_unlock(&cdev->lock);
799 
800 	return len;
801 }
802 
803 static DEVICE_ATTR_RO(total_trans);
804 static DEVICE_ATTR_RO(time_in_state_ms);
805 static DEVICE_ATTR_WO(reset);
806 static DEVICE_ATTR_RO(trans_table);
807 
808 static struct attribute *cooling_device_stats_attrs[] = {
809 	&dev_attr_total_trans.attr,
810 	&dev_attr_time_in_state_ms.attr,
811 	&dev_attr_reset.attr,
812 	&dev_attr_trans_table.attr,
813 	NULL
814 };
815 
816 static const struct attribute_group cooling_device_stats_attr_group = {
817 	.attrs = cooling_device_stats_attrs,
818 	.name = "stats"
819 };
820 
821 static void cooling_device_stats_setup(struct thermal_cooling_device *cdev)
822 {
823 	const struct attribute_group *stats_attr_group = NULL;
824 	struct cooling_dev_stats *stats;
825 	/* Total number of states is highest state + 1 */
826 	unsigned long states = cdev->max_state + 1;
827 	int var;
828 
829 	var = sizeof(*stats);
830 	var += sizeof(*stats->time_in_state) * states;
831 	var += sizeof(*stats->trans_table) * states * states;
832 
833 	stats = kzalloc(var, GFP_KERNEL);
834 	if (!stats)
835 		goto out;
836 
837 	stats->time_in_state = (ktime_t *)(stats + 1);
838 	stats->trans_table = (unsigned int *)(stats->time_in_state + states);
839 	cdev->stats = stats;
840 	stats->last_time = ktime_get();
841 
842 	spin_lock_init(&stats->lock);
843 
844 	stats_attr_group = &cooling_device_stats_attr_group;
845 
846 out:
847 	/* Fill the empty slot left in cooling_device_attr_groups */
848 	var = ARRAY_SIZE(cooling_device_attr_groups) - 2;
849 	cooling_device_attr_groups[var] = stats_attr_group;
850 }
851 
852 static void cooling_device_stats_destroy(struct thermal_cooling_device *cdev)
853 {
854 	kfree(cdev->stats);
855 	cdev->stats = NULL;
856 }
857 
858 #else
859 
860 static inline void
861 cooling_device_stats_setup(struct thermal_cooling_device *cdev) {}
862 static inline void
863 cooling_device_stats_destroy(struct thermal_cooling_device *cdev) {}
864 
865 #endif /* CONFIG_THERMAL_STATISTICS */
866 
867 void thermal_cooling_device_setup_sysfs(struct thermal_cooling_device *cdev)
868 {
869 	cooling_device_stats_setup(cdev);
870 	cdev->device.groups = cooling_device_attr_groups;
871 }
872 
873 void thermal_cooling_device_destroy_sysfs(struct thermal_cooling_device *cdev)
874 {
875 	cooling_device_stats_destroy(cdev);
876 }
877 
878 void thermal_cooling_device_stats_reinit(struct thermal_cooling_device *cdev)
879 {
880 	lockdep_assert_held(&cdev->lock);
881 
882 	cooling_device_stats_destroy(cdev);
883 	cooling_device_stats_setup(cdev);
884 }
885 
886 /* these helper will be used only at the time of bindig */
887 ssize_t
888 trip_point_show(struct device *dev, struct device_attribute *attr, char *buf)
889 {
890 	struct thermal_instance *instance;
891 
892 	instance =
893 	    container_of(attr, struct thermal_instance, attr);
894 
895 	return sprintf(buf, "%d\n",
896 		       thermal_zone_trip_id(instance->tz, instance->trip));
897 }
898 
899 ssize_t
900 weight_show(struct device *dev, struct device_attribute *attr, char *buf)
901 {
902 	struct thermal_instance *instance;
903 
904 	instance = container_of(attr, struct thermal_instance, weight_attr);
905 
906 	return sprintf(buf, "%d\n", instance->weight);
907 }
908 
909 ssize_t weight_store(struct device *dev, struct device_attribute *attr,
910 		     const char *buf, size_t count)
911 {
912 	struct thermal_instance *instance;
913 	int ret, weight;
914 
915 	ret = kstrtoint(buf, 0, &weight);
916 	if (ret)
917 		return ret;
918 
919 	instance = container_of(attr, struct thermal_instance, weight_attr);
920 
921 	/* Don't race with governors using the 'weight' value */
922 	mutex_lock(&instance->tz->lock);
923 
924 	instance->weight = weight;
925 
926 	thermal_governor_update_tz(instance->tz,
927 				   THERMAL_INSTANCE_WEIGHT_CHANGED);
928 
929 	mutex_unlock(&instance->tz->lock);
930 
931 	return count;
932 }
933