xref: /linux/drivers/thermal/thermal_sysfs.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
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/container_of.h>
16 #include <linux/sysfs.h>
17 #include <linux/device.h>
18 #include <linux/err.h>
19 #include <linux/slab.h>
20 #include <linux/string.h>
21 #include <linux/jiffies.h>
22 
23 #include "thermal_core.h"
24 
25 /* sys I/F for thermal zone */
26 
27 static ssize_t
28 type_show(struct device *dev, struct device_attribute *attr, char *buf)
29 {
30 	struct thermal_zone_device *tz = to_thermal_zone(dev);
31 
32 	return sprintf(buf, "%s\n", tz->type);
33 }
34 
35 static ssize_t
36 temp_show(struct device *dev, struct device_attribute *attr, char *buf)
37 {
38 	struct thermal_zone_device *tz = to_thermal_zone(dev);
39 	int temperature, ret;
40 
41 	ret = thermal_zone_get_temp(tz, &temperature);
42 
43 	if (ret)
44 		return ret;
45 
46 	return sprintf(buf, "%d\n", temperature);
47 }
48 
49 static ssize_t
50 mode_show(struct device *dev, struct device_attribute *attr, char *buf)
51 {
52 	struct thermal_zone_device *tz = to_thermal_zone(dev);
53 
54 	guard(thermal_zone)(tz);
55 
56 	if (tz->mode == THERMAL_DEVICE_ENABLED)
57 		return sprintf(buf, "enabled\n");
58 
59 	return sprintf(buf, "disabled\n");
60 }
61 
62 static ssize_t
63 mode_store(struct device *dev, struct device_attribute *attr,
64 	   const char *buf, size_t count)
65 {
66 	struct thermal_zone_device *tz = to_thermal_zone(dev);
67 	int result;
68 
69 	if (!strncmp(buf, "enabled", sizeof("enabled") - 1))
70 		result = thermal_zone_device_enable(tz);
71 	else if (!strncmp(buf, "disabled", sizeof("disabled") - 1))
72 		result = thermal_zone_device_disable(tz);
73 	else
74 		result = -EINVAL;
75 
76 	if (result)
77 		return result;
78 
79 	return count;
80 }
81 
82 #define thermal_trip_of_attr(_ptr_, _attr_)				\
83 	({ 								\
84 		struct thermal_trip_desc *td;				\
85 									\
86 		td = container_of(_ptr_, struct thermal_trip_desc,	\
87 				  trip_attrs._attr_.attr);		\
88 		&td->trip;						\
89 	})
90 
91 static ssize_t
92 trip_point_type_show(struct device *dev, struct device_attribute *attr,
93 		     char *buf)
94 {
95 	struct thermal_trip *trip = thermal_trip_of_attr(attr, type);
96 
97 	return sprintf(buf, "%s\n", thermal_trip_type_name(trip->type));
98 }
99 
100 static ssize_t
101 trip_point_temp_store(struct device *dev, struct device_attribute *attr,
102 		      const char *buf, size_t count)
103 {
104 	struct thermal_trip *trip = thermal_trip_of_attr(attr, temp);
105 	struct thermal_zone_device *tz = to_thermal_zone(dev);
106 	int temp;
107 
108 	if (kstrtoint(buf, 10, &temp))
109 		return -EINVAL;
110 
111 	guard(thermal_zone)(tz);
112 
113 	if (temp == trip->temperature)
114 		return count;
115 
116 	/* Arrange the condition to avoid integer overflows. */
117 	if (temp != THERMAL_TEMP_INVALID &&
118 	    temp <= trip->hysteresis + THERMAL_TEMP_INVALID)
119 		return -EINVAL;
120 
121 	if (tz->ops.set_trip_temp) {
122 		int ret;
123 
124 		ret = tz->ops.set_trip_temp(tz, trip, temp);
125 		if (ret)
126 			return ret;
127 	}
128 
129 	thermal_zone_set_trip_temp(tz, trip, temp);
130 
131 	__thermal_zone_device_update(tz, THERMAL_TRIP_CHANGED);
132 
133 	return count;
134 }
135 
136 static ssize_t
137 trip_point_temp_show(struct device *dev, struct device_attribute *attr,
138 		     char *buf)
139 {
140 	struct thermal_trip *trip = thermal_trip_of_attr(attr, temp);
141 
142 	return sprintf(buf, "%d\n", READ_ONCE(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_trip *trip = thermal_trip_of_attr(attr, hyst);
150 	struct thermal_zone_device *tz = to_thermal_zone(dev);
151 	int hyst;
152 
153 	if (kstrtoint(buf, 10, &hyst) || hyst < 0)
154 		return -EINVAL;
155 
156 	guard(thermal_zone)(tz);
157 
158 	if (hyst == trip->hysteresis)
159 		return count;
160 
161 	/*
162 	 * Allow the hysteresis to be updated when the temperature is invalid
163 	 * to allow user space to avoid having to adjust hysteresis after a
164 	 * valid temperature has been set, but in that case just change the
165 	 * value and do nothing else.
166 	 */
167 	if (trip->temperature == THERMAL_TEMP_INVALID) {
168 		WRITE_ONCE(trip->hysteresis, hyst);
169 		return count;
170 	}
171 
172 	if (trip->temperature - hyst <= THERMAL_TEMP_INVALID)
173 		return -EINVAL;
174 
175 	thermal_zone_set_trip_hyst(tz, trip, hyst);
176 
177 	__thermal_zone_device_update(tz, THERMAL_TRIP_CHANGED);
178 
179 	return count;
180 }
181 
182 static ssize_t
183 trip_point_hyst_show(struct device *dev, struct device_attribute *attr,
184 		     char *buf)
185 {
186 	struct thermal_trip *trip = thermal_trip_of_attr(attr, hyst);
187 
188 	return sprintf(buf, "%d\n", READ_ONCE(trip->hysteresis));
189 }
190 
191 static ssize_t
192 policy_store(struct device *dev, struct device_attribute *attr,
193 	     const char *buf, size_t count)
194 {
195 	struct thermal_zone_device *tz = to_thermal_zone(dev);
196 	char name[THERMAL_NAME_LENGTH];
197 	int ret;
198 
199 	snprintf(name, sizeof(name), "%s", buf);
200 
201 	ret = thermal_zone_device_set_policy(tz, name);
202 	if (!ret)
203 		ret = count;
204 
205 	return ret;
206 }
207 
208 static ssize_t
209 policy_show(struct device *dev, struct device_attribute *devattr, char *buf)
210 {
211 	struct thermal_zone_device *tz = to_thermal_zone(dev);
212 
213 	return sprintf(buf, "%s\n", tz->governor->name);
214 }
215 
216 static ssize_t
217 available_policies_show(struct device *dev, struct device_attribute *devattr,
218 			char *buf)
219 {
220 	return thermal_build_list_of_policies(buf);
221 }
222 
223 #if (IS_ENABLED(CONFIG_THERMAL_EMULATION))
224 static ssize_t
225 emul_temp_store(struct device *dev, struct device_attribute *attr,
226 		const char *buf, size_t count)
227 {
228 	struct thermal_zone_device *tz = to_thermal_zone(dev);
229 	int temperature;
230 
231 	if (kstrtoint(buf, 10, &temperature))
232 		return -EINVAL;
233 
234 	guard(thermal_zone)(tz);
235 
236 	if (tz->ops.set_emul_temp) {
237 		int ret;
238 
239 		ret = tz->ops.set_emul_temp(tz, temperature);
240 		if (ret)
241 			return ret;
242 	} else {
243 		tz->emul_temperature = temperature;
244 	}
245 
246 	__thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
247 
248 	return count;
249 }
250 static DEVICE_ATTR_WO(emul_temp);
251 #endif
252 
253 static ssize_t
254 sustainable_power_show(struct device *dev, struct device_attribute *devattr,
255 		       char *buf)
256 {
257 	struct thermal_zone_device *tz = to_thermal_zone(dev);
258 
259 	if (tz->tzp)
260 		return sprintf(buf, "%u\n", tz->tzp->sustainable_power);
261 	else
262 		return -EIO;
263 }
264 
265 static ssize_t
266 sustainable_power_store(struct device *dev, struct device_attribute *devattr,
267 			const char *buf, size_t count)
268 {
269 	struct thermal_zone_device *tz = to_thermal_zone(dev);
270 	u32 sustainable_power;
271 
272 	if (!tz->tzp)
273 		return -EIO;
274 
275 	if (kstrtou32(buf, 10, &sustainable_power))
276 		return -EINVAL;
277 
278 	tz->tzp->sustainable_power = sustainable_power;
279 
280 	return count;
281 }
282 
283 #define create_s32_tzp_attr(name)					\
284 	static ssize_t							\
285 	name##_show(struct device *dev, struct device_attribute *devattr, \
286 		char *buf)						\
287 	{								\
288 	struct thermal_zone_device *tz = to_thermal_zone(dev);		\
289 									\
290 	if (tz->tzp)							\
291 		return sprintf(buf, "%d\n", tz->tzp->name);		\
292 	else								\
293 		return -EIO;						\
294 	}								\
295 									\
296 	static ssize_t							\
297 	name##_store(struct device *dev, struct device_attribute *devattr, \
298 		const char *buf, size_t count)				\
299 	{								\
300 		struct thermal_zone_device *tz = to_thermal_zone(dev);	\
301 		s32 value;						\
302 									\
303 		if (!tz->tzp)						\
304 			return -EIO;					\
305 									\
306 		if (kstrtos32(buf, 10, &value))				\
307 			return -EINVAL;					\
308 									\
309 		tz->tzp->name = value;					\
310 									\
311 		return count;						\
312 	}								\
313 	static DEVICE_ATTR_RW(name)
314 
315 create_s32_tzp_attr(k_po);
316 create_s32_tzp_attr(k_pu);
317 create_s32_tzp_attr(k_i);
318 create_s32_tzp_attr(k_d);
319 create_s32_tzp_attr(integral_cutoff);
320 create_s32_tzp_attr(slope);
321 create_s32_tzp_attr(offset);
322 #undef create_s32_tzp_attr
323 
324 /*
325  * These are thermal zone device attributes that will always be present.
326  * All the attributes created for tzp (create_s32_tzp_attr) also are always
327  * present on the sysfs interface.
328  */
329 static DEVICE_ATTR_RO(type);
330 static DEVICE_ATTR_RO(temp);
331 static DEVICE_ATTR_RW(policy);
332 static DEVICE_ATTR_RO(available_policies);
333 static DEVICE_ATTR_RW(sustainable_power);
334 
335 /* These thermal zone device attributes are created based on conditions */
336 static DEVICE_ATTR_RW(mode);
337 
338 /* These attributes are unconditionally added to a thermal zone */
339 static struct attribute *thermal_zone_dev_attrs[] = {
340 	&dev_attr_type.attr,
341 	&dev_attr_temp.attr,
342 #if (IS_ENABLED(CONFIG_THERMAL_EMULATION))
343 	&dev_attr_emul_temp.attr,
344 #endif
345 	&dev_attr_policy.attr,
346 	&dev_attr_available_policies.attr,
347 	&dev_attr_sustainable_power.attr,
348 	&dev_attr_k_po.attr,
349 	&dev_attr_k_pu.attr,
350 	&dev_attr_k_i.attr,
351 	&dev_attr_k_d.attr,
352 	&dev_attr_integral_cutoff.attr,
353 	&dev_attr_slope.attr,
354 	&dev_attr_offset.attr,
355 	NULL,
356 };
357 
358 static const struct attribute_group thermal_zone_attribute_group = {
359 	.attrs = thermal_zone_dev_attrs,
360 };
361 
362 static struct attribute *thermal_zone_mode_attrs[] = {
363 	&dev_attr_mode.attr,
364 	NULL,
365 };
366 
367 static const struct attribute_group thermal_zone_mode_attribute_group = {
368 	.attrs = thermal_zone_mode_attrs,
369 };
370 
371 static const struct attribute_group *thermal_zone_attribute_groups[] = {
372 	&thermal_zone_attribute_group,
373 	&thermal_zone_mode_attribute_group,
374 	/* This is not NULL terminated as we create the group dynamically */
375 };
376 
377 /**
378  * create_trip_attrs() - create attributes for trip points
379  * @tz:		the thermal zone device
380  *
381  * helper function to instantiate sysfs entries for every trip
382  * point and its properties of a struct thermal_zone_device.
383  *
384  * Return: 0 on success, the proper error value otherwise.
385  */
386 static int create_trip_attrs(struct thermal_zone_device *tz)
387 {
388 	struct thermal_trip_desc *td;
389 	struct attribute **attrs;
390 	int i;
391 
392 	attrs = kcalloc(tz->num_trips * 3 + 1, sizeof(*attrs), GFP_KERNEL);
393 	if (!attrs)
394 		return -ENOMEM;
395 
396 	i = 0;
397 	for_each_trip_desc(tz, td) {
398 		struct thermal_trip_attrs *trip_attrs = &td->trip_attrs;
399 
400 		/* create trip type attribute */
401 		snprintf(trip_attrs->type.name, THERMAL_NAME_LENGTH,
402 			 "trip_point_%d_type", i);
403 
404 		sysfs_attr_init(&trip_attrs->type.attr.attr);
405 		trip_attrs->type.attr.attr.name = trip_attrs->type.name;
406 		trip_attrs->type.attr.attr.mode = S_IRUGO;
407 		trip_attrs->type.attr.show = trip_point_type_show;
408 		attrs[i] = &trip_attrs->type.attr.attr;
409 
410 		/* create trip temp attribute */
411 		snprintf(trip_attrs->temp.name, THERMAL_NAME_LENGTH,
412 			 "trip_point_%d_temp", i);
413 
414 		sysfs_attr_init(&trip_attrs->temp.attr.attr);
415 		trip_attrs->temp.attr.attr.name = trip_attrs->temp.name;
416 		trip_attrs->temp.attr.attr.mode = S_IRUGO;
417 		trip_attrs->temp.attr.show = trip_point_temp_show;
418 		if (td->trip.flags & THERMAL_TRIP_FLAG_RW_TEMP) {
419 			trip_attrs->temp.attr.attr.mode |= S_IWUSR;
420 			trip_attrs->temp.attr.store = trip_point_temp_store;
421 		}
422 		attrs[i + tz->num_trips] = &trip_attrs->temp.attr.attr;
423 
424 		snprintf(trip_attrs->hyst.name, THERMAL_NAME_LENGTH,
425 			 "trip_point_%d_hyst", i);
426 
427 		sysfs_attr_init(&trip_attrs->hyst.attr.attr);
428 		trip_attrs->hyst.attr.attr.name = trip_attrs->hyst.name;
429 		trip_attrs->hyst.attr.attr.mode = S_IRUGO;
430 		trip_attrs->hyst.attr.show = trip_point_hyst_show;
431 		if (td->trip.flags & THERMAL_TRIP_FLAG_RW_HYST) {
432 			trip_attrs->hyst.attr.attr.mode |= S_IWUSR;
433 			trip_attrs->hyst.attr.store = trip_point_hyst_store;
434 		}
435 		attrs[i + 2 * tz->num_trips] = &trip_attrs->hyst.attr.attr;
436 		i++;
437 	}
438 	attrs[tz->num_trips * 3] = NULL;
439 
440 	tz->trips_attribute_group.attrs = attrs;
441 
442 	return 0;
443 }
444 
445 /**
446  * destroy_trip_attrs() - destroy attributes for trip points
447  * @tz:		the thermal zone device
448  *
449  * helper function to free resources allocated by create_trip_attrs()
450  */
451 static void destroy_trip_attrs(struct thermal_zone_device *tz)
452 {
453 	if (tz)
454 		kfree(tz->trips_attribute_group.attrs);
455 }
456 
457 int thermal_zone_create_device_groups(struct thermal_zone_device *tz)
458 {
459 	const struct attribute_group **groups;
460 	int i, size, result;
461 
462 	/* we need one extra for trips and the NULL to terminate the array */
463 	size = ARRAY_SIZE(thermal_zone_attribute_groups) + 2;
464 	/* This also takes care of API requirement to be NULL terminated */
465 	groups = kcalloc(size, sizeof(*groups), GFP_KERNEL);
466 	if (!groups)
467 		return -ENOMEM;
468 
469 	for (i = 0; i < size - 2; i++)
470 		groups[i] = thermal_zone_attribute_groups[i];
471 
472 	if (tz->num_trips) {
473 		result = create_trip_attrs(tz);
474 		if (result) {
475 			kfree(groups);
476 
477 			return result;
478 		}
479 
480 		groups[size - 2] = &tz->trips_attribute_group;
481 	}
482 
483 	tz->device.groups = groups;
484 
485 	return 0;
486 }
487 
488 void thermal_zone_destroy_device_groups(struct thermal_zone_device *tz)
489 {
490 	if (!tz)
491 		return;
492 
493 	if (tz->num_trips)
494 		destroy_trip_attrs(tz);
495 
496 	kfree(tz->device.groups);
497 }
498 
499 /* sys I/F for cooling device */
500 static ssize_t
501 cdev_type_show(struct device *dev, struct device_attribute *attr, char *buf)
502 {
503 	struct thermal_cooling_device *cdev = to_cooling_device(dev);
504 
505 	return sprintf(buf, "%s\n", cdev->type);
506 }
507 
508 static ssize_t max_state_show(struct device *dev, struct device_attribute *attr,
509 			      char *buf)
510 {
511 	struct thermal_cooling_device *cdev = to_cooling_device(dev);
512 
513 	return sprintf(buf, "%ld\n", cdev->max_state);
514 }
515 
516 static ssize_t cur_state_show(struct device *dev, struct device_attribute *attr,
517 			      char *buf)
518 {
519 	struct thermal_cooling_device *cdev = to_cooling_device(dev);
520 	unsigned long state;
521 	int ret;
522 
523 	ret = cdev->ops->get_cur_state(cdev, &state);
524 	if (ret)
525 		return ret;
526 	return sprintf(buf, "%ld\n", state);
527 }
528 
529 static ssize_t
530 cur_state_store(struct device *dev, struct device_attribute *attr,
531 		const char *buf, size_t count)
532 {
533 	struct thermal_cooling_device *cdev = to_cooling_device(dev);
534 	unsigned long state;
535 	int result;
536 
537 	if (sscanf(buf, "%ld\n", &state) != 1)
538 		return -EINVAL;
539 
540 	if ((long)state < 0)
541 		return -EINVAL;
542 
543 	/* Requested state should be less than max_state + 1 */
544 	if (state > cdev->max_state)
545 		return -EINVAL;
546 
547 	guard(cooling_dev)(cdev);
548 
549 	result = cdev->ops->set_cur_state(cdev, state);
550 	if (result)
551 		return result;
552 
553 	thermal_cooling_device_stats_update(cdev, state);
554 
555 	return count;
556 }
557 
558 static struct device_attribute
559 dev_attr_cdev_type = __ATTR(type, 0444, cdev_type_show, NULL);
560 static DEVICE_ATTR_RO(max_state);
561 static DEVICE_ATTR_RW(cur_state);
562 
563 static struct attribute *cooling_device_attrs[] = {
564 	&dev_attr_cdev_type.attr,
565 	&dev_attr_max_state.attr,
566 	&dev_attr_cur_state.attr,
567 	NULL,
568 };
569 
570 static const struct attribute_group cooling_device_attr_group = {
571 	.attrs = cooling_device_attrs,
572 };
573 
574 static const struct attribute_group *cooling_device_attr_groups[] = {
575 	&cooling_device_attr_group,
576 	NULL, /* Space allocated for cooling_device_stats_attr_group */
577 	NULL,
578 };
579 
580 #ifdef CONFIG_THERMAL_STATISTICS
581 struct cooling_dev_stats {
582 	spinlock_t lock;
583 	unsigned int total_trans;
584 	unsigned long state;
585 	ktime_t last_time;
586 	ktime_t *time_in_state;
587 	unsigned int *trans_table;
588 };
589 
590 static void update_time_in_state(struct cooling_dev_stats *stats)
591 {
592 	ktime_t now = ktime_get(), delta;
593 
594 	delta = ktime_sub(now, stats->last_time);
595 	stats->time_in_state[stats->state] =
596 		ktime_add(stats->time_in_state[stats->state], delta);
597 	stats->last_time = now;
598 }
599 
600 void thermal_cooling_device_stats_update(struct thermal_cooling_device *cdev,
601 					 unsigned long new_state)
602 {
603 	struct cooling_dev_stats *stats = cdev->stats;
604 
605 	lockdep_assert_held(&cdev->lock);
606 
607 	if (!stats)
608 		return;
609 
610 	spin_lock(&stats->lock);
611 
612 	if (stats->state == new_state)
613 		goto unlock;
614 
615 	update_time_in_state(stats);
616 	stats->trans_table[stats->state * (cdev->max_state + 1) + new_state]++;
617 	stats->state = new_state;
618 	stats->total_trans++;
619 
620 unlock:
621 	spin_unlock(&stats->lock);
622 }
623 
624 static ssize_t total_trans_show(struct device *dev,
625 				struct device_attribute *attr, char *buf)
626 {
627 	struct thermal_cooling_device *cdev = to_cooling_device(dev);
628 	struct cooling_dev_stats *stats;
629 	int ret;
630 
631 	guard(cooling_dev)(cdev);
632 
633 	stats = cdev->stats;
634 	if (!stats)
635 		return 0;
636 
637 	spin_lock(&stats->lock);
638 	ret = sprintf(buf, "%u\n", stats->total_trans);
639 	spin_unlock(&stats->lock);
640 
641 	return ret;
642 }
643 
644 static ssize_t
645 time_in_state_ms_show(struct device *dev, struct device_attribute *attr,
646 		      char *buf)
647 {
648 	struct thermal_cooling_device *cdev = to_cooling_device(dev);
649 	struct cooling_dev_stats *stats;
650 	ssize_t len = 0;
651 	int i;
652 
653 	guard(cooling_dev)(cdev);
654 
655 	stats = cdev->stats;
656 	if (!stats)
657 		return 0;
658 
659 	spin_lock(&stats->lock);
660 
661 	update_time_in_state(stats);
662 
663 	for (i = 0; i <= cdev->max_state; i++) {
664 		len += sprintf(buf + len, "state%u\t%llu\n", i,
665 			       ktime_to_ms(stats->time_in_state[i]));
666 	}
667 	spin_unlock(&stats->lock);
668 
669 	return len;
670 }
671 
672 static ssize_t
673 reset_store(struct device *dev, struct device_attribute *attr, const char *buf,
674 	    size_t count)
675 {
676 	struct thermal_cooling_device *cdev = to_cooling_device(dev);
677 	struct cooling_dev_stats *stats;
678 	int i, states;
679 
680 	guard(cooling_dev)(cdev);
681 
682 	stats = cdev->stats;
683 	if (!stats)
684 		return count;
685 
686 	states = cdev->max_state + 1;
687 
688 	spin_lock(&stats->lock);
689 
690 	stats->total_trans = 0;
691 	stats->last_time = ktime_get();
692 	memset(stats->trans_table, 0,
693 	       states * states * sizeof(*stats->trans_table));
694 
695 	for (i = 0; i < states; i++)
696 		stats->time_in_state[i] = ktime_set(0, 0);
697 
698 	spin_unlock(&stats->lock);
699 
700 	return count;
701 }
702 
703 static ssize_t trans_table_show(struct device *dev,
704 				struct device_attribute *attr, char *buf)
705 {
706 	struct thermal_cooling_device *cdev = to_cooling_device(dev);
707 	struct cooling_dev_stats *stats;
708 	ssize_t len = 0;
709 	int i, j;
710 
711 	guard(cooling_dev)(cdev);
712 
713 	stats = cdev->stats;
714 	if (!stats)
715 		return -ENODATA;
716 
717 	len += snprintf(buf + len, PAGE_SIZE - len, " From  :    To\n");
718 	len += snprintf(buf + len, PAGE_SIZE - len, "       : ");
719 	for (i = 0; i <= cdev->max_state; i++) {
720 		if (len >= PAGE_SIZE)
721 			break;
722 		len += snprintf(buf + len, PAGE_SIZE - len, "state%2u  ", i);
723 	}
724 	if (len >= PAGE_SIZE)
725 		return PAGE_SIZE;
726 
727 	len += snprintf(buf + len, PAGE_SIZE - len, "\n");
728 
729 	for (i = 0; i <= cdev->max_state; i++) {
730 		if (len >= PAGE_SIZE)
731 			break;
732 
733 		len += snprintf(buf + len, PAGE_SIZE - len, "state%2u:", i);
734 
735 		for (j = 0; j <= cdev->max_state; j++) {
736 			if (len >= PAGE_SIZE)
737 				break;
738 			len += snprintf(buf + len, PAGE_SIZE - len, "%8u ",
739 				stats->trans_table[i * (cdev->max_state + 1) + j]);
740 		}
741 		if (len >= PAGE_SIZE)
742 			break;
743 		len += snprintf(buf + len, PAGE_SIZE - len, "\n");
744 	}
745 
746 	if (len >= PAGE_SIZE) {
747 		pr_warn_once("Thermal transition table exceeds PAGE_SIZE. Disabling\n");
748 		len = -EFBIG;
749 	}
750 
751 	return len;
752 }
753 
754 static DEVICE_ATTR_RO(total_trans);
755 static DEVICE_ATTR_RO(time_in_state_ms);
756 static DEVICE_ATTR_WO(reset);
757 static DEVICE_ATTR_RO(trans_table);
758 
759 static struct attribute *cooling_device_stats_attrs[] = {
760 	&dev_attr_total_trans.attr,
761 	&dev_attr_time_in_state_ms.attr,
762 	&dev_attr_reset.attr,
763 	&dev_attr_trans_table.attr,
764 	NULL
765 };
766 
767 static const struct attribute_group cooling_device_stats_attr_group = {
768 	.attrs = cooling_device_stats_attrs,
769 	.name = "stats"
770 };
771 
772 static void cooling_device_stats_setup(struct thermal_cooling_device *cdev)
773 {
774 	const struct attribute_group *stats_attr_group = NULL;
775 	struct cooling_dev_stats *stats;
776 	/* Total number of states is highest state + 1 */
777 	unsigned long states = cdev->max_state + 1;
778 	int var;
779 
780 	var = sizeof(*stats);
781 	var += sizeof(*stats->time_in_state) * states;
782 	var += sizeof(*stats->trans_table) * states * states;
783 
784 	stats = kzalloc(var, GFP_KERNEL);
785 	if (!stats)
786 		goto out;
787 
788 	stats->time_in_state = (ktime_t *)(stats + 1);
789 	stats->trans_table = (unsigned int *)(stats->time_in_state + states);
790 	cdev->stats = stats;
791 	stats->last_time = ktime_get();
792 
793 	spin_lock_init(&stats->lock);
794 
795 	stats_attr_group = &cooling_device_stats_attr_group;
796 
797 out:
798 	/* Fill the empty slot left in cooling_device_attr_groups */
799 	var = ARRAY_SIZE(cooling_device_attr_groups) - 2;
800 	cooling_device_attr_groups[var] = stats_attr_group;
801 }
802 
803 static void cooling_device_stats_destroy(struct thermal_cooling_device *cdev)
804 {
805 	kfree(cdev->stats);
806 	cdev->stats = NULL;
807 }
808 
809 #else
810 
811 static inline void
812 cooling_device_stats_setup(struct thermal_cooling_device *cdev) {}
813 static inline void
814 cooling_device_stats_destroy(struct thermal_cooling_device *cdev) {}
815 
816 #endif /* CONFIG_THERMAL_STATISTICS */
817 
818 void thermal_cooling_device_setup_sysfs(struct thermal_cooling_device *cdev)
819 {
820 	cooling_device_stats_setup(cdev);
821 	cdev->device.groups = cooling_device_attr_groups;
822 }
823 
824 void thermal_cooling_device_destroy_sysfs(struct thermal_cooling_device *cdev)
825 {
826 	cooling_device_stats_destroy(cdev);
827 }
828 
829 void thermal_cooling_device_stats_reinit(struct thermal_cooling_device *cdev)
830 {
831 	lockdep_assert_held(&cdev->lock);
832 
833 	cooling_device_stats_destroy(cdev);
834 	cooling_device_stats_setup(cdev);
835 }
836 
837 /* these helper will be used only at the time of bindig */
838 ssize_t
839 trip_point_show(struct device *dev, struct device_attribute *attr, char *buf)
840 {
841 	struct thermal_zone_device *tz = to_thermal_zone(dev);
842 	struct thermal_instance *instance;
843 
844 	instance = container_of(attr, struct thermal_instance, attr);
845 
846 	return sprintf(buf, "%d\n", thermal_zone_trip_id(tz, instance->trip));
847 }
848 
849 ssize_t
850 weight_show(struct device *dev, struct device_attribute *attr, char *buf)
851 {
852 	struct thermal_instance *instance;
853 
854 	instance = container_of(attr, struct thermal_instance, weight_attr);
855 
856 	return sprintf(buf, "%d\n", instance->weight);
857 }
858 
859 ssize_t weight_store(struct device *dev, struct device_attribute *attr,
860 		     const char *buf, size_t count)
861 {
862 	struct thermal_zone_device *tz = to_thermal_zone(dev);
863 	struct thermal_instance *instance;
864 	int ret, weight;
865 
866 	ret = kstrtoint(buf, 0, &weight);
867 	if (ret)
868 		return ret;
869 
870 	instance = container_of(attr, struct thermal_instance, weight_attr);
871 
872 	/* Don't race with governors using the 'weight' value */
873 	guard(thermal_zone)(tz);
874 
875 	instance->weight = weight;
876 
877 	thermal_governor_update_tz(tz, THERMAL_INSTANCE_WEIGHT_CHANGED);
878 
879 	return count;
880 }
881