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 	struct thermal_trip trip;
87 	int trip_id, result;
88 
89 	if (sscanf(attr->attr.name, "trip_point_%d_type", &trip_id) != 1)
90 		return -EINVAL;
91 
92 	mutex_lock(&tz->lock);
93 
94 	if (device_is_registered(dev))
95 		result = __thermal_zone_get_trip(tz, trip_id, &trip);
96 	else
97 		result = -ENODEV;
98 
99 	mutex_unlock(&tz->lock);
100 
101 	if (result)
102 		return result;
103 
104 	switch (trip.type) {
105 	case THERMAL_TRIP_CRITICAL:
106 		return sprintf(buf, "critical\n");
107 	case THERMAL_TRIP_HOT:
108 		return sprintf(buf, "hot\n");
109 	case THERMAL_TRIP_PASSIVE:
110 		return sprintf(buf, "passive\n");
111 	case THERMAL_TRIP_ACTIVE:
112 		return sprintf(buf, "active\n");
113 	default:
114 		return sprintf(buf, "unknown\n");
115 	}
116 }
117 
118 static ssize_t
119 trip_point_temp_store(struct device *dev, struct device_attribute *attr,
120 		      const char *buf, size_t count)
121 {
122 	struct thermal_zone_device *tz = to_thermal_zone(dev);
123 	struct thermal_trip trip;
124 	int trip_id, ret;
125 
126 	if (sscanf(attr->attr.name, "trip_point_%d_temp", &trip_id) != 1)
127 		return -EINVAL;
128 
129 	mutex_lock(&tz->lock);
130 
131 	if (!device_is_registered(dev)) {
132 		ret = -ENODEV;
133 		goto unlock;
134 	}
135 
136 	ret = __thermal_zone_get_trip(tz, trip_id, &trip);
137 	if (ret)
138 		goto unlock;
139 
140 	ret = kstrtoint(buf, 10, &trip.temperature);
141 	if (ret)
142 		goto unlock;
143 
144 	ret = thermal_zone_set_trip(tz, trip_id, &trip);
145 unlock:
146 	mutex_unlock(&tz->lock);
147 
148 	return ret ? ret : count;
149 }
150 
151 static ssize_t
152 trip_point_temp_show(struct device *dev, struct device_attribute *attr,
153 		     char *buf)
154 {
155 	struct thermal_zone_device *tz = to_thermal_zone(dev);
156 	struct thermal_trip trip;
157 	int trip_id, ret;
158 
159 	if (sscanf(attr->attr.name, "trip_point_%d_temp", &trip_id) != 1)
160 		return -EINVAL;
161 
162 	mutex_lock(&tz->lock);
163 
164 	if (device_is_registered(dev))
165 		ret = __thermal_zone_get_trip(tz, trip_id, &trip);
166 	else
167 		ret = -ENODEV;
168 
169 	mutex_unlock(&tz->lock);
170 
171 	if (ret)
172 		return ret;
173 
174 	return sprintf(buf, "%d\n", trip.temperature);
175 }
176 
177 static ssize_t
178 trip_point_hyst_store(struct device *dev, struct device_attribute *attr,
179 		      const char *buf, size_t count)
180 {
181 	struct thermal_zone_device *tz = to_thermal_zone(dev);
182 	struct thermal_trip trip;
183 	int trip_id, ret;
184 
185 	if (sscanf(attr->attr.name, "trip_point_%d_hyst", &trip_id) != 1)
186 		return -EINVAL;
187 
188 	if (kstrtoint(buf, 10, &trip.hysteresis))
189 		return -EINVAL;
190 
191 	mutex_lock(&tz->lock);
192 
193 	if (!device_is_registered(dev)) {
194 		ret = -ENODEV;
195 		goto unlock;
196 	}
197 
198 	ret = __thermal_zone_get_trip(tz, trip_id, &trip);
199 	if (ret)
200 		goto unlock;
201 
202 	ret = thermal_zone_set_trip(tz, trip_id, &trip);
203 unlock:
204 	mutex_unlock(&tz->lock);
205 
206 	return ret ? ret : count;
207 }
208 
209 static ssize_t
210 trip_point_hyst_show(struct device *dev, struct device_attribute *attr,
211 		     char *buf)
212 {
213 	struct thermal_zone_device *tz = to_thermal_zone(dev);
214 	struct thermal_trip trip;
215 	int trip_id, ret;
216 
217 	if (sscanf(attr->attr.name, "trip_point_%d_hyst", &trip_id) != 1)
218 		return -EINVAL;
219 
220 	mutex_lock(&tz->lock);
221 
222 	if (device_is_registered(dev))
223 		ret = __thermal_zone_get_trip(tz, trip_id, &trip);
224 	else
225 		ret = -ENODEV;
226 
227 	mutex_unlock(&tz->lock);
228 
229 	return ret ? ret : sprintf(buf, "%d\n", trip.hysteresis);
230 }
231 
232 static ssize_t
233 policy_store(struct device *dev, struct device_attribute *attr,
234 	     const char *buf, size_t count)
235 {
236 	struct thermal_zone_device *tz = to_thermal_zone(dev);
237 	char name[THERMAL_NAME_LENGTH];
238 	int ret;
239 
240 	snprintf(name, sizeof(name), "%s", buf);
241 
242 	ret = thermal_zone_device_set_policy(tz, name);
243 	if (!ret)
244 		ret = count;
245 
246 	return ret;
247 }
248 
249 static ssize_t
250 policy_show(struct device *dev, struct device_attribute *devattr, char *buf)
251 {
252 	struct thermal_zone_device *tz = to_thermal_zone(dev);
253 
254 	return sprintf(buf, "%s\n", tz->governor->name);
255 }
256 
257 static ssize_t
258 available_policies_show(struct device *dev, struct device_attribute *devattr,
259 			char *buf)
260 {
261 	return thermal_build_list_of_policies(buf);
262 }
263 
264 #if (IS_ENABLED(CONFIG_THERMAL_EMULATION))
265 static ssize_t
266 emul_temp_store(struct device *dev, struct device_attribute *attr,
267 		const char *buf, size_t count)
268 {
269 	struct thermal_zone_device *tz = to_thermal_zone(dev);
270 	int ret = 0;
271 	int temperature;
272 
273 	if (kstrtoint(buf, 10, &temperature))
274 		return -EINVAL;
275 
276 	mutex_lock(&tz->lock);
277 
278 	if (!device_is_registered(dev)) {
279 		ret = -ENODEV;
280 		goto unlock;
281 	}
282 
283 	if (!tz->ops->set_emul_temp)
284 		tz->emul_temperature = temperature;
285 	else
286 		ret = tz->ops->set_emul_temp(tz, temperature);
287 
288 	if (!ret)
289 		__thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
290 
291 unlock:
292 	mutex_unlock(&tz->lock);
293 
294 	return ret ? ret : count;
295 }
296 static DEVICE_ATTR_WO(emul_temp);
297 #endif
298 
299 static ssize_t
300 sustainable_power_show(struct device *dev, struct device_attribute *devattr,
301 		       char *buf)
302 {
303 	struct thermal_zone_device *tz = to_thermal_zone(dev);
304 
305 	if (tz->tzp)
306 		return sprintf(buf, "%u\n", tz->tzp->sustainable_power);
307 	else
308 		return -EIO;
309 }
310 
311 static ssize_t
312 sustainable_power_store(struct device *dev, struct device_attribute *devattr,
313 			const char *buf, size_t count)
314 {
315 	struct thermal_zone_device *tz = to_thermal_zone(dev);
316 	u32 sustainable_power;
317 
318 	if (!tz->tzp)
319 		return -EIO;
320 
321 	if (kstrtou32(buf, 10, &sustainable_power))
322 		return -EINVAL;
323 
324 	tz->tzp->sustainable_power = sustainable_power;
325 
326 	return count;
327 }
328 
329 #define create_s32_tzp_attr(name)					\
330 	static ssize_t							\
331 	name##_show(struct device *dev, struct device_attribute *devattr, \
332 		char *buf)						\
333 	{								\
334 	struct thermal_zone_device *tz = to_thermal_zone(dev);		\
335 									\
336 	if (tz->tzp)							\
337 		return sprintf(buf, "%d\n", tz->tzp->name);		\
338 	else								\
339 		return -EIO;						\
340 	}								\
341 									\
342 	static ssize_t							\
343 	name##_store(struct device *dev, struct device_attribute *devattr, \
344 		const char *buf, size_t count)				\
345 	{								\
346 		struct thermal_zone_device *tz = to_thermal_zone(dev);	\
347 		s32 value;						\
348 									\
349 		if (!tz->tzp)						\
350 			return -EIO;					\
351 									\
352 		if (kstrtos32(buf, 10, &value))				\
353 			return -EINVAL;					\
354 									\
355 		tz->tzp->name = value;					\
356 									\
357 		return count;						\
358 	}								\
359 	static DEVICE_ATTR_RW(name)
360 
361 create_s32_tzp_attr(k_po);
362 create_s32_tzp_attr(k_pu);
363 create_s32_tzp_attr(k_i);
364 create_s32_tzp_attr(k_d);
365 create_s32_tzp_attr(integral_cutoff);
366 create_s32_tzp_attr(slope);
367 create_s32_tzp_attr(offset);
368 #undef create_s32_tzp_attr
369 
370 /*
371  * These are thermal zone device attributes that will always be present.
372  * All the attributes created for tzp (create_s32_tzp_attr) also are always
373  * present on the sysfs interface.
374  */
375 static DEVICE_ATTR_RO(type);
376 static DEVICE_ATTR_RO(temp);
377 static DEVICE_ATTR_RW(policy);
378 static DEVICE_ATTR_RO(available_policies);
379 static DEVICE_ATTR_RW(sustainable_power);
380 
381 /* These thermal zone device attributes are created based on conditions */
382 static DEVICE_ATTR_RW(mode);
383 
384 /* These attributes are unconditionally added to a thermal zone */
385 static struct attribute *thermal_zone_dev_attrs[] = {
386 	&dev_attr_type.attr,
387 	&dev_attr_temp.attr,
388 #if (IS_ENABLED(CONFIG_THERMAL_EMULATION))
389 	&dev_attr_emul_temp.attr,
390 #endif
391 	&dev_attr_policy.attr,
392 	&dev_attr_available_policies.attr,
393 	&dev_attr_sustainable_power.attr,
394 	&dev_attr_k_po.attr,
395 	&dev_attr_k_pu.attr,
396 	&dev_attr_k_i.attr,
397 	&dev_attr_k_d.attr,
398 	&dev_attr_integral_cutoff.attr,
399 	&dev_attr_slope.attr,
400 	&dev_attr_offset.attr,
401 	NULL,
402 };
403 
404 static const struct attribute_group thermal_zone_attribute_group = {
405 	.attrs = thermal_zone_dev_attrs,
406 };
407 
408 static struct attribute *thermal_zone_mode_attrs[] = {
409 	&dev_attr_mode.attr,
410 	NULL,
411 };
412 
413 static const struct attribute_group thermal_zone_mode_attribute_group = {
414 	.attrs = thermal_zone_mode_attrs,
415 };
416 
417 static const struct attribute_group *thermal_zone_attribute_groups[] = {
418 	&thermal_zone_attribute_group,
419 	&thermal_zone_mode_attribute_group,
420 	/* This is not NULL terminated as we create the group dynamically */
421 };
422 
423 /**
424  * create_trip_attrs() - create attributes for trip points
425  * @tz:		the thermal zone device
426  * @mask:	Writeable trip point bitmap.
427  *
428  * helper function to instantiate sysfs entries for every trip
429  * point and its properties of a struct thermal_zone_device.
430  *
431  * Return: 0 on success, the proper error value otherwise.
432  */
433 static int create_trip_attrs(struct thermal_zone_device *tz, int mask)
434 {
435 	struct attribute **attrs;
436 	int indx;
437 
438 	/* This function works only for zones with at least one trip */
439 	if (tz->num_trips <= 0)
440 		return -EINVAL;
441 
442 	tz->trip_type_attrs = kcalloc(tz->num_trips, sizeof(*tz->trip_type_attrs),
443 				      GFP_KERNEL);
444 	if (!tz->trip_type_attrs)
445 		return -ENOMEM;
446 
447 	tz->trip_temp_attrs = kcalloc(tz->num_trips, sizeof(*tz->trip_temp_attrs),
448 				      GFP_KERNEL);
449 	if (!tz->trip_temp_attrs) {
450 		kfree(tz->trip_type_attrs);
451 		return -ENOMEM;
452 	}
453 
454 	tz->trip_hyst_attrs = kcalloc(tz->num_trips,
455 				      sizeof(*tz->trip_hyst_attrs),
456 				      GFP_KERNEL);
457 	if (!tz->trip_hyst_attrs) {
458 		kfree(tz->trip_type_attrs);
459 		kfree(tz->trip_temp_attrs);
460 		return -ENOMEM;
461 	}
462 
463 	attrs = kcalloc(tz->num_trips * 3 + 1, sizeof(*attrs), GFP_KERNEL);
464 	if (!attrs) {
465 		kfree(tz->trip_type_attrs);
466 		kfree(tz->trip_temp_attrs);
467 		kfree(tz->trip_hyst_attrs);
468 		return -ENOMEM;
469 	}
470 
471 	for (indx = 0; indx < tz->num_trips; indx++) {
472 		/* create trip type attribute */
473 		snprintf(tz->trip_type_attrs[indx].name, THERMAL_NAME_LENGTH,
474 			 "trip_point_%d_type", indx);
475 
476 		sysfs_attr_init(&tz->trip_type_attrs[indx].attr.attr);
477 		tz->trip_type_attrs[indx].attr.attr.name =
478 						tz->trip_type_attrs[indx].name;
479 		tz->trip_type_attrs[indx].attr.attr.mode = S_IRUGO;
480 		tz->trip_type_attrs[indx].attr.show = trip_point_type_show;
481 		attrs[indx] = &tz->trip_type_attrs[indx].attr.attr;
482 
483 		/* create trip temp attribute */
484 		snprintf(tz->trip_temp_attrs[indx].name, THERMAL_NAME_LENGTH,
485 			 "trip_point_%d_temp", indx);
486 
487 		sysfs_attr_init(&tz->trip_temp_attrs[indx].attr.attr);
488 		tz->trip_temp_attrs[indx].attr.attr.name =
489 						tz->trip_temp_attrs[indx].name;
490 		tz->trip_temp_attrs[indx].attr.attr.mode = S_IRUGO;
491 		tz->trip_temp_attrs[indx].attr.show = trip_point_temp_show;
492 		if (IS_ENABLED(CONFIG_THERMAL_WRITABLE_TRIPS) &&
493 		    mask & (1 << indx)) {
494 			tz->trip_temp_attrs[indx].attr.attr.mode |= S_IWUSR;
495 			tz->trip_temp_attrs[indx].attr.store =
496 							trip_point_temp_store;
497 		}
498 		attrs[indx + tz->num_trips] = &tz->trip_temp_attrs[indx].attr.attr;
499 
500 		snprintf(tz->trip_hyst_attrs[indx].name, THERMAL_NAME_LENGTH,
501 			 "trip_point_%d_hyst", indx);
502 
503 		sysfs_attr_init(&tz->trip_hyst_attrs[indx].attr.attr);
504 		tz->trip_hyst_attrs[indx].attr.attr.name =
505 					tz->trip_hyst_attrs[indx].name;
506 		tz->trip_hyst_attrs[indx].attr.attr.mode = S_IRUGO;
507 		tz->trip_hyst_attrs[indx].attr.show = trip_point_hyst_show;
508 		if (tz->ops->set_trip_hyst) {
509 			tz->trip_hyst_attrs[indx].attr.attr.mode |= S_IWUSR;
510 			tz->trip_hyst_attrs[indx].attr.store =
511 					trip_point_hyst_store;
512 		}
513 		attrs[indx + tz->num_trips * 2] =
514 					&tz->trip_hyst_attrs[indx].attr.attr;
515 	}
516 	attrs[tz->num_trips * 3] = NULL;
517 
518 	tz->trips_attribute_group.attrs = attrs;
519 
520 	return 0;
521 }
522 
523 /**
524  * destroy_trip_attrs() - destroy attributes for trip points
525  * @tz:		the thermal zone device
526  *
527  * helper function to free resources allocated by create_trip_attrs()
528  */
529 static void destroy_trip_attrs(struct thermal_zone_device *tz)
530 {
531 	if (!tz)
532 		return;
533 
534 	kfree(tz->trip_type_attrs);
535 	kfree(tz->trip_temp_attrs);
536 	kfree(tz->trip_hyst_attrs);
537 	kfree(tz->trips_attribute_group.attrs);
538 }
539 
540 int thermal_zone_create_device_groups(struct thermal_zone_device *tz,
541 				      int mask)
542 {
543 	const struct attribute_group **groups;
544 	int i, size, result;
545 
546 	/* we need one extra for trips and the NULL to terminate the array */
547 	size = ARRAY_SIZE(thermal_zone_attribute_groups) + 2;
548 	/* This also takes care of API requirement to be NULL terminated */
549 	groups = kcalloc(size, sizeof(*groups), GFP_KERNEL);
550 	if (!groups)
551 		return -ENOMEM;
552 
553 	for (i = 0; i < size - 2; i++)
554 		groups[i] = thermal_zone_attribute_groups[i];
555 
556 	if (tz->num_trips) {
557 		result = create_trip_attrs(tz, mask);
558 		if (result) {
559 			kfree(groups);
560 
561 			return result;
562 		}
563 
564 		groups[size - 2] = &tz->trips_attribute_group;
565 	}
566 
567 	tz->device.groups = groups;
568 
569 	return 0;
570 }
571 
572 void thermal_zone_destroy_device_groups(struct thermal_zone_device *tz)
573 {
574 	if (!tz)
575 		return;
576 
577 	if (tz->num_trips)
578 		destroy_trip_attrs(tz);
579 
580 	kfree(tz->device.groups);
581 }
582 
583 /* sys I/F for cooling device */
584 static ssize_t
585 cdev_type_show(struct device *dev, struct device_attribute *attr, char *buf)
586 {
587 	struct thermal_cooling_device *cdev = to_cooling_device(dev);
588 
589 	return sprintf(buf, "%s\n", cdev->type);
590 }
591 
592 static ssize_t max_state_show(struct device *dev, struct device_attribute *attr,
593 			      char *buf)
594 {
595 	struct thermal_cooling_device *cdev = to_cooling_device(dev);
596 
597 	return sprintf(buf, "%ld\n", cdev->max_state);
598 }
599 
600 static ssize_t cur_state_show(struct device *dev, struct device_attribute *attr,
601 			      char *buf)
602 {
603 	struct thermal_cooling_device *cdev = to_cooling_device(dev);
604 	unsigned long state;
605 	int ret;
606 
607 	ret = cdev->ops->get_cur_state(cdev, &state);
608 	if (ret)
609 		return ret;
610 	return sprintf(buf, "%ld\n", state);
611 }
612 
613 static ssize_t
614 cur_state_store(struct device *dev, struct device_attribute *attr,
615 		const char *buf, size_t count)
616 {
617 	struct thermal_cooling_device *cdev = to_cooling_device(dev);
618 	unsigned long state;
619 	int result;
620 
621 	if (sscanf(buf, "%ld\n", &state) != 1)
622 		return -EINVAL;
623 
624 	if ((long)state < 0)
625 		return -EINVAL;
626 
627 	/* Requested state should be less than max_state + 1 */
628 	if (state > cdev->max_state)
629 		return -EINVAL;
630 
631 	mutex_lock(&cdev->lock);
632 
633 	result = cdev->ops->set_cur_state(cdev, state);
634 	if (!result)
635 		thermal_cooling_device_stats_update(cdev, state);
636 
637 	mutex_unlock(&cdev->lock);
638 	return result ? result : count;
639 }
640 
641 static struct device_attribute
642 dev_attr_cdev_type = __ATTR(type, 0444, cdev_type_show, NULL);
643 static DEVICE_ATTR_RO(max_state);
644 static DEVICE_ATTR_RW(cur_state);
645 
646 static struct attribute *cooling_device_attrs[] = {
647 	&dev_attr_cdev_type.attr,
648 	&dev_attr_max_state.attr,
649 	&dev_attr_cur_state.attr,
650 	NULL,
651 };
652 
653 static const struct attribute_group cooling_device_attr_group = {
654 	.attrs = cooling_device_attrs,
655 };
656 
657 static const struct attribute_group *cooling_device_attr_groups[] = {
658 	&cooling_device_attr_group,
659 	NULL, /* Space allocated for cooling_device_stats_attr_group */
660 	NULL,
661 };
662 
663 #ifdef CONFIG_THERMAL_STATISTICS
664 struct cooling_dev_stats {
665 	spinlock_t lock;
666 	unsigned int total_trans;
667 	unsigned long state;
668 	ktime_t last_time;
669 	ktime_t *time_in_state;
670 	unsigned int *trans_table;
671 };
672 
673 static void update_time_in_state(struct cooling_dev_stats *stats)
674 {
675 	ktime_t now = ktime_get(), delta;
676 
677 	delta = ktime_sub(now, stats->last_time);
678 	stats->time_in_state[stats->state] =
679 		ktime_add(stats->time_in_state[stats->state], delta);
680 	stats->last_time = now;
681 }
682 
683 void thermal_cooling_device_stats_update(struct thermal_cooling_device *cdev,
684 					 unsigned long new_state)
685 {
686 	struct cooling_dev_stats *stats = cdev->stats;
687 
688 	lockdep_assert_held(&cdev->lock);
689 
690 	if (!stats)
691 		return;
692 
693 	spin_lock(&stats->lock);
694 
695 	if (stats->state == new_state)
696 		goto unlock;
697 
698 	update_time_in_state(stats);
699 	stats->trans_table[stats->state * (cdev->max_state + 1) + new_state]++;
700 	stats->state = new_state;
701 	stats->total_trans++;
702 
703 unlock:
704 	spin_unlock(&stats->lock);
705 }
706 
707 static ssize_t total_trans_show(struct device *dev,
708 				struct device_attribute *attr, char *buf)
709 {
710 	struct thermal_cooling_device *cdev = to_cooling_device(dev);
711 	struct cooling_dev_stats *stats;
712 	int ret = 0;
713 
714 	mutex_lock(&cdev->lock);
715 
716 	stats = cdev->stats;
717 	if (!stats)
718 		goto unlock;
719 
720 	spin_lock(&stats->lock);
721 	ret = sprintf(buf, "%u\n", stats->total_trans);
722 	spin_unlock(&stats->lock);
723 
724 unlock:
725 	mutex_unlock(&cdev->lock);
726 
727 	return ret;
728 }
729 
730 static ssize_t
731 time_in_state_ms_show(struct device *dev, struct device_attribute *attr,
732 		      char *buf)
733 {
734 	struct thermal_cooling_device *cdev = to_cooling_device(dev);
735 	struct cooling_dev_stats *stats;
736 	ssize_t len = 0;
737 	int i;
738 
739 	mutex_lock(&cdev->lock);
740 
741 	stats = cdev->stats;
742 	if (!stats)
743 		goto unlock;
744 
745 	spin_lock(&stats->lock);
746 
747 	update_time_in_state(stats);
748 
749 	for (i = 0; i <= cdev->max_state; i++) {
750 		len += sprintf(buf + len, "state%u\t%llu\n", i,
751 			       ktime_to_ms(stats->time_in_state[i]));
752 	}
753 	spin_unlock(&stats->lock);
754 
755 unlock:
756 	mutex_unlock(&cdev->lock);
757 
758 	return len;
759 }
760 
761 static ssize_t
762 reset_store(struct device *dev, struct device_attribute *attr, const char *buf,
763 	    size_t count)
764 {
765 	struct thermal_cooling_device *cdev = to_cooling_device(dev);
766 	struct cooling_dev_stats *stats;
767 	int i, states;
768 
769 	mutex_lock(&cdev->lock);
770 
771 	stats = cdev->stats;
772 	if (!stats)
773 		goto unlock;
774 
775 	states = cdev->max_state + 1;
776 
777 	spin_lock(&stats->lock);
778 
779 	stats->total_trans = 0;
780 	stats->last_time = ktime_get();
781 	memset(stats->trans_table, 0,
782 	       states * states * sizeof(*stats->trans_table));
783 
784 	for (i = 0; i < states; i++)
785 		stats->time_in_state[i] = ktime_set(0, 0);
786 
787 	spin_unlock(&stats->lock);
788 
789 unlock:
790 	mutex_unlock(&cdev->lock);
791 
792 	return count;
793 }
794 
795 static ssize_t trans_table_show(struct device *dev,
796 				struct device_attribute *attr, char *buf)
797 {
798 	struct thermal_cooling_device *cdev = to_cooling_device(dev);
799 	struct cooling_dev_stats *stats;
800 	ssize_t len = 0;
801 	int i, j;
802 
803 	mutex_lock(&cdev->lock);
804 
805 	stats = cdev->stats;
806 	if (!stats) {
807 		len = -ENODATA;
808 		goto unlock;
809 	}
810 
811 	len += snprintf(buf + len, PAGE_SIZE - len, " From  :    To\n");
812 	len += snprintf(buf + len, PAGE_SIZE - len, "       : ");
813 	for (i = 0; i <= cdev->max_state; i++) {
814 		if (len >= PAGE_SIZE)
815 			break;
816 		len += snprintf(buf + len, PAGE_SIZE - len, "state%2u  ", i);
817 	}
818 	if (len >= PAGE_SIZE) {
819 		len = PAGE_SIZE;
820 		goto unlock;
821 	}
822 
823 	len += snprintf(buf + len, PAGE_SIZE - len, "\n");
824 
825 	for (i = 0; i <= cdev->max_state; i++) {
826 		if (len >= PAGE_SIZE)
827 			break;
828 
829 		len += snprintf(buf + len, PAGE_SIZE - len, "state%2u:", i);
830 
831 		for (j = 0; j <= cdev->max_state; j++) {
832 			if (len >= PAGE_SIZE)
833 				break;
834 			len += snprintf(buf + len, PAGE_SIZE - len, "%8u ",
835 				stats->trans_table[i * (cdev->max_state + 1) + j]);
836 		}
837 		if (len >= PAGE_SIZE)
838 			break;
839 		len += snprintf(buf + len, PAGE_SIZE - len, "\n");
840 	}
841 
842 	if (len >= PAGE_SIZE) {
843 		pr_warn_once("Thermal transition table exceeds PAGE_SIZE. Disabling\n");
844 		len = -EFBIG;
845 	}
846 
847 unlock:
848 	mutex_unlock(&cdev->lock);
849 
850 	return len;
851 }
852 
853 static DEVICE_ATTR_RO(total_trans);
854 static DEVICE_ATTR_RO(time_in_state_ms);
855 static DEVICE_ATTR_WO(reset);
856 static DEVICE_ATTR_RO(trans_table);
857 
858 static struct attribute *cooling_device_stats_attrs[] = {
859 	&dev_attr_total_trans.attr,
860 	&dev_attr_time_in_state_ms.attr,
861 	&dev_attr_reset.attr,
862 	&dev_attr_trans_table.attr,
863 	NULL
864 };
865 
866 static const struct attribute_group cooling_device_stats_attr_group = {
867 	.attrs = cooling_device_stats_attrs,
868 	.name = "stats"
869 };
870 
871 static void cooling_device_stats_setup(struct thermal_cooling_device *cdev)
872 {
873 	const struct attribute_group *stats_attr_group = NULL;
874 	struct cooling_dev_stats *stats;
875 	/* Total number of states is highest state + 1 */
876 	unsigned long states = cdev->max_state + 1;
877 	int var;
878 
879 	lockdep_assert_held(&cdev->lock);
880 
881 	var = sizeof(*stats);
882 	var += sizeof(*stats->time_in_state) * states;
883 	var += sizeof(*stats->trans_table) * states * states;
884 
885 	stats = kzalloc(var, GFP_KERNEL);
886 	if (!stats)
887 		goto out;
888 
889 	stats->time_in_state = (ktime_t *)(stats + 1);
890 	stats->trans_table = (unsigned int *)(stats->time_in_state + states);
891 	cdev->stats = stats;
892 	stats->last_time = ktime_get();
893 
894 	spin_lock_init(&stats->lock);
895 
896 	stats_attr_group = &cooling_device_stats_attr_group;
897 
898 out:
899 	/* Fill the empty slot left in cooling_device_attr_groups */
900 	var = ARRAY_SIZE(cooling_device_attr_groups) - 2;
901 	cooling_device_attr_groups[var] = stats_attr_group;
902 }
903 
904 static void cooling_device_stats_destroy(struct thermal_cooling_device *cdev)
905 {
906 	lockdep_assert_held(&cdev->lock);
907 
908 	kfree(cdev->stats);
909 	cdev->stats = NULL;
910 }
911 
912 #else
913 
914 static inline void
915 cooling_device_stats_setup(struct thermal_cooling_device *cdev) {}
916 static inline void
917 cooling_device_stats_destroy(struct thermal_cooling_device *cdev) {}
918 
919 #endif /* CONFIG_THERMAL_STATISTICS */
920 
921 void thermal_cooling_device_setup_sysfs(struct thermal_cooling_device *cdev)
922 {
923 	cooling_device_stats_setup(cdev);
924 	cdev->device.groups = cooling_device_attr_groups;
925 }
926 
927 void thermal_cooling_device_destroy_sysfs(struct thermal_cooling_device *cdev)
928 {
929 	cooling_device_stats_destroy(cdev);
930 }
931 
932 void thermal_cooling_device_stats_reinit(struct thermal_cooling_device *cdev)
933 {
934 	cooling_device_stats_destroy(cdev);
935 	cooling_device_stats_setup(cdev);
936 }
937 
938 /* these helper will be used only at the time of bindig */
939 ssize_t
940 trip_point_show(struct device *dev, struct device_attribute *attr, char *buf)
941 {
942 	struct thermal_instance *instance;
943 
944 	instance =
945 	    container_of(attr, struct thermal_instance, attr);
946 
947 	return sprintf(buf, "%d\n", instance->trip);
948 }
949 
950 ssize_t
951 weight_show(struct device *dev, struct device_attribute *attr, char *buf)
952 {
953 	struct thermal_instance *instance;
954 
955 	instance = container_of(attr, struct thermal_instance, weight_attr);
956 
957 	return sprintf(buf, "%d\n", instance->weight);
958 }
959 
960 ssize_t weight_store(struct device *dev, struct device_attribute *attr,
961 		     const char *buf, size_t count)
962 {
963 	struct thermal_instance *instance;
964 	int ret, weight;
965 
966 	ret = kstrtoint(buf, 0, &weight);
967 	if (ret)
968 		return ret;
969 
970 	instance = container_of(attr, struct thermal_instance, weight_attr);
971 	instance->weight = weight;
972 
973 	return count;
974 }
975