xref: /linux/drivers/thermal/thermal_core.c (revision b1992c3772e69a6fd0e3fc81cd4d2820c8b6eca0)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  thermal.c - Generic Thermal Management Sysfs support.
4  *
5  *  Copyright (C) 2008 Intel Corp
6  *  Copyright (C) 2008 Zhang Rui <rui.zhang@intel.com>
7  *  Copyright (C) 2008 Sujith Thomas <sujith.thomas@intel.com>
8  */
9 
10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11 
12 #include <linux/device.h>
13 #include <linux/err.h>
14 #include <linux/export.h>
15 #include <linux/slab.h>
16 #include <linux/kdev_t.h>
17 #include <linux/idr.h>
18 #include <linux/thermal.h>
19 #include <linux/reboot.h>
20 #include <linux/string.h>
21 #include <linux/of.h>
22 #include <linux/suspend.h>
23 
24 #define CREATE_TRACE_POINTS
25 #include "thermal_trace.h"
26 
27 #include "thermal_core.h"
28 #include "thermal_hwmon.h"
29 
30 static DEFINE_IDA(thermal_tz_ida);
31 static DEFINE_IDA(thermal_cdev_ida);
32 
33 static LIST_HEAD(thermal_tz_list);
34 static LIST_HEAD(thermal_cdev_list);
35 static LIST_HEAD(thermal_governor_list);
36 
37 static DEFINE_MUTEX(thermal_list_lock);
38 static DEFINE_MUTEX(thermal_governor_lock);
39 
40 static struct thermal_governor *def_governor;
41 
42 /*
43  * Governor section: set of functions to handle thermal governors
44  *
45  * Functions to help in the life cycle of thermal governors within
46  * the thermal core and by the thermal governor code.
47  */
48 
49 static struct thermal_governor *__find_governor(const char *name)
50 {
51 	struct thermal_governor *pos;
52 
53 	if (!name || !name[0])
54 		return def_governor;
55 
56 	list_for_each_entry(pos, &thermal_governor_list, governor_list)
57 		if (!strncasecmp(name, pos->name, THERMAL_NAME_LENGTH))
58 			return pos;
59 
60 	return NULL;
61 }
62 
63 /**
64  * bind_previous_governor() - bind the previous governor of the thermal zone
65  * @tz:		a valid pointer to a struct thermal_zone_device
66  * @failed_gov_name:	the name of the governor that failed to register
67  *
68  * Register the previous governor of the thermal zone after a new
69  * governor has failed to be bound.
70  */
71 static void bind_previous_governor(struct thermal_zone_device *tz,
72 				   const char *failed_gov_name)
73 {
74 	if (tz->governor && tz->governor->bind_to_tz) {
75 		if (tz->governor->bind_to_tz(tz)) {
76 			dev_err(&tz->device,
77 				"governor %s failed to bind and the previous one (%s) failed to bind again, thermal zone %s has no governor\n",
78 				failed_gov_name, tz->governor->name, tz->type);
79 			tz->governor = NULL;
80 		}
81 	}
82 }
83 
84 /**
85  * thermal_set_governor() - Switch to another governor
86  * @tz:		a valid pointer to a struct thermal_zone_device
87  * @new_gov:	pointer to the new governor
88  *
89  * Change the governor of thermal zone @tz.
90  *
91  * Return: 0 on success, an error if the new governor's bind_to_tz() failed.
92  */
93 static int thermal_set_governor(struct thermal_zone_device *tz,
94 				struct thermal_governor *new_gov)
95 {
96 	int ret = 0;
97 
98 	if (tz->governor && tz->governor->unbind_from_tz)
99 		tz->governor->unbind_from_tz(tz);
100 
101 	if (new_gov && new_gov->bind_to_tz) {
102 		ret = new_gov->bind_to_tz(tz);
103 		if (ret) {
104 			bind_previous_governor(tz, new_gov->name);
105 
106 			return ret;
107 		}
108 	}
109 
110 	tz->governor = new_gov;
111 
112 	return ret;
113 }
114 
115 int thermal_register_governor(struct thermal_governor *governor)
116 {
117 	int err;
118 	const char *name;
119 	struct thermal_zone_device *pos;
120 
121 	if (!governor)
122 		return -EINVAL;
123 
124 	mutex_lock(&thermal_governor_lock);
125 
126 	err = -EBUSY;
127 	if (!__find_governor(governor->name)) {
128 		bool match_default;
129 
130 		err = 0;
131 		list_add(&governor->governor_list, &thermal_governor_list);
132 		match_default = !strncmp(governor->name,
133 					 DEFAULT_THERMAL_GOVERNOR,
134 					 THERMAL_NAME_LENGTH);
135 
136 		if (!def_governor && match_default)
137 			def_governor = governor;
138 	}
139 
140 	mutex_lock(&thermal_list_lock);
141 
142 	list_for_each_entry(pos, &thermal_tz_list, node) {
143 		/*
144 		 * only thermal zones with specified tz->tzp->governor_name
145 		 * may run with tz->govenor unset
146 		 */
147 		if (pos->governor)
148 			continue;
149 
150 		name = pos->tzp->governor_name;
151 
152 		if (!strncasecmp(name, governor->name, THERMAL_NAME_LENGTH)) {
153 			int ret;
154 
155 			ret = thermal_set_governor(pos, governor);
156 			if (ret)
157 				dev_err(&pos->device,
158 					"Failed to set governor %s for thermal zone %s: %d\n",
159 					governor->name, pos->type, ret);
160 		}
161 	}
162 
163 	mutex_unlock(&thermal_list_lock);
164 	mutex_unlock(&thermal_governor_lock);
165 
166 	return err;
167 }
168 
169 void thermal_unregister_governor(struct thermal_governor *governor)
170 {
171 	struct thermal_zone_device *pos;
172 
173 	if (!governor)
174 		return;
175 
176 	mutex_lock(&thermal_governor_lock);
177 
178 	if (!__find_governor(governor->name))
179 		goto exit;
180 
181 	mutex_lock(&thermal_list_lock);
182 
183 	list_for_each_entry(pos, &thermal_tz_list, node) {
184 		if (!strncasecmp(pos->governor->name, governor->name,
185 				 THERMAL_NAME_LENGTH))
186 			thermal_set_governor(pos, NULL);
187 	}
188 
189 	mutex_unlock(&thermal_list_lock);
190 	list_del(&governor->governor_list);
191 exit:
192 	mutex_unlock(&thermal_governor_lock);
193 }
194 
195 int thermal_zone_device_set_policy(struct thermal_zone_device *tz,
196 				   char *policy)
197 {
198 	struct thermal_governor *gov;
199 	int ret = -EINVAL;
200 
201 	mutex_lock(&thermal_governor_lock);
202 	mutex_lock(&tz->lock);
203 
204 	gov = __find_governor(strim(policy));
205 	if (!gov)
206 		goto exit;
207 
208 	ret = thermal_set_governor(tz, gov);
209 
210 exit:
211 	mutex_unlock(&tz->lock);
212 	mutex_unlock(&thermal_governor_lock);
213 
214 	thermal_notify_tz_gov_change(tz, policy);
215 
216 	return ret;
217 }
218 
219 int thermal_build_list_of_policies(char *buf)
220 {
221 	struct thermal_governor *pos;
222 	ssize_t count = 0;
223 
224 	mutex_lock(&thermal_governor_lock);
225 
226 	list_for_each_entry(pos, &thermal_governor_list, governor_list) {
227 		count += sysfs_emit_at(buf, count, "%s ", pos->name);
228 	}
229 	count += sysfs_emit_at(buf, count, "\n");
230 
231 	mutex_unlock(&thermal_governor_lock);
232 
233 	return count;
234 }
235 
236 static void __init thermal_unregister_governors(void)
237 {
238 	struct thermal_governor **governor;
239 
240 	for_each_governor_table(governor)
241 		thermal_unregister_governor(*governor);
242 }
243 
244 static int __init thermal_register_governors(void)
245 {
246 	int ret = 0;
247 	struct thermal_governor **governor;
248 
249 	for_each_governor_table(governor) {
250 		ret = thermal_register_governor(*governor);
251 		if (ret) {
252 			pr_err("Failed to register governor: '%s'",
253 			       (*governor)->name);
254 			break;
255 		}
256 
257 		pr_info("Registered thermal governor '%s'",
258 			(*governor)->name);
259 	}
260 
261 	if (ret) {
262 		struct thermal_governor **gov;
263 
264 		for_each_governor_table(gov) {
265 			if (gov == governor)
266 				break;
267 			thermal_unregister_governor(*gov);
268 		}
269 	}
270 
271 	return ret;
272 }
273 
274 /*
275  * Zone update section: main control loop applied to each zone while monitoring
276  * in polling mode. The monitoring is done using a workqueue.
277  * Same update may be done on a zone by calling thermal_zone_device_update().
278  *
279  * An update means:
280  * - Non-critical trips will invoke the governor responsible for that zone;
281  * - Hot trips will produce a notification to userspace;
282  * - Critical trip point will cause a system shutdown.
283  */
284 static void thermal_zone_device_set_polling(struct thermal_zone_device *tz,
285 					    unsigned long delay)
286 {
287 	if (delay)
288 		mod_delayed_work(system_freezable_power_efficient_wq,
289 				 &tz->poll_queue, delay);
290 	else
291 		cancel_delayed_work(&tz->poll_queue);
292 }
293 
294 static void monitor_thermal_zone(struct thermal_zone_device *tz)
295 {
296 	if (tz->mode != THERMAL_DEVICE_ENABLED)
297 		thermal_zone_device_set_polling(tz, 0);
298 	else if (tz->passive)
299 		thermal_zone_device_set_polling(tz, tz->passive_delay_jiffies);
300 	else if (tz->polling_delay_jiffies)
301 		thermal_zone_device_set_polling(tz, tz->polling_delay_jiffies);
302 }
303 
304 static void handle_non_critical_trips(struct thermal_zone_device *tz,
305 				      const struct thermal_trip *trip)
306 {
307 	tz->governor ? tz->governor->throttle(tz, trip) :
308 		       def_governor->throttle(tz, trip);
309 }
310 
311 void thermal_governor_update_tz(struct thermal_zone_device *tz,
312 				enum thermal_notify_event reason)
313 {
314 	if (!tz->governor || !tz->governor->update_tz)
315 		return;
316 
317 	tz->governor->update_tz(tz, reason);
318 }
319 
320 static void thermal_zone_device_halt(struct thermal_zone_device *tz, bool shutdown)
321 {
322 	/*
323 	 * poweroff_delay_ms must be a carefully profiled positive value.
324 	 * Its a must for forced_emergency_poweroff_work to be scheduled.
325 	 */
326 	int poweroff_delay_ms = CONFIG_THERMAL_EMERGENCY_POWEROFF_DELAY_MS;
327 	const char *msg = "Temperature too high";
328 
329 	dev_emerg(&tz->device, "%s: critical temperature reached\n", tz->type);
330 
331 	if (shutdown)
332 		hw_protection_shutdown(msg, poweroff_delay_ms);
333 	else
334 		hw_protection_reboot(msg, poweroff_delay_ms);
335 }
336 
337 void thermal_zone_device_critical(struct thermal_zone_device *tz)
338 {
339 	thermal_zone_device_halt(tz, true);
340 }
341 EXPORT_SYMBOL(thermal_zone_device_critical);
342 
343 void thermal_zone_device_critical_reboot(struct thermal_zone_device *tz)
344 {
345 	thermal_zone_device_halt(tz, false);
346 }
347 
348 static void handle_critical_trips(struct thermal_zone_device *tz,
349 				  const struct thermal_trip *trip)
350 {
351 	/* If we have not crossed the trip_temp, we do not care. */
352 	if (trip->temperature <= 0 || tz->temperature < trip->temperature)
353 		return;
354 
355 	trace_thermal_zone_trip(tz, thermal_zone_trip_id(tz, trip), trip->type);
356 
357 	if (trip->type == THERMAL_TRIP_CRITICAL)
358 		tz->ops.critical(tz);
359 	else if (tz->ops.hot)
360 		tz->ops.hot(tz);
361 }
362 
363 static void handle_thermal_trip(struct thermal_zone_device *tz,
364 				struct thermal_trip *trip)
365 {
366 	if (trip->temperature == THERMAL_TEMP_INVALID)
367 		return;
368 
369 	if (tz->last_temperature == THERMAL_TEMP_INVALID) {
370 		/* Initialization. */
371 		trip->threshold = trip->temperature;
372 		if (tz->temperature >= trip->threshold)
373 			trip->threshold -= trip->hysteresis;
374 	} else if (tz->last_temperature < trip->threshold) {
375 		/*
376 		 * The trip threshold is equal to the trip temperature, unless
377 		 * the latter has changed in the meantime.  In either case,
378 		 * the trip is crossed if the current zone temperature is at
379 		 * least equal to its temperature, but otherwise ensure that
380 		 * the threshold and the trip temperature will be equal.
381 		 */
382 		if (tz->temperature >= trip->temperature) {
383 			thermal_notify_tz_trip_up(tz, trip);
384 			thermal_debug_tz_trip_up(tz, trip);
385 			trip->threshold = trip->temperature - trip->hysteresis;
386 		} else {
387 			trip->threshold = trip->temperature;
388 		}
389 	} else {
390 		/*
391 		 * The previous zone temperature was above or equal to the trip
392 		 * threshold, which would be equal to the "low temperature" of
393 		 * the trip (its temperature minus its hysteresis), unless the
394 		 * trip temperature or hysteresis had changed.  In either case,
395 		 * the trip is crossed if the current zone temperature is below
396 		 * the low temperature of the trip, but otherwise ensure that
397 		 * the trip threshold will be equal to the low temperature of
398 		 * the trip.
399 		 */
400 		if (tz->temperature < trip->temperature - trip->hysteresis) {
401 			thermal_notify_tz_trip_down(tz, trip);
402 			thermal_debug_tz_trip_down(tz, trip);
403 			trip->threshold = trip->temperature;
404 		} else {
405 			trip->threshold = trip->temperature - trip->hysteresis;
406 		}
407 	}
408 
409 	if (trip->type == THERMAL_TRIP_CRITICAL || trip->type == THERMAL_TRIP_HOT)
410 		handle_critical_trips(tz, trip);
411 	else
412 		handle_non_critical_trips(tz, trip);
413 }
414 
415 static void update_temperature(struct thermal_zone_device *tz)
416 {
417 	int temp, ret;
418 
419 	ret = __thermal_zone_get_temp(tz, &temp);
420 	if (ret) {
421 		if (ret != -EAGAIN)
422 			dev_warn(&tz->device,
423 				 "failed to read out thermal zone (%d)\n",
424 				 ret);
425 		return;
426 	}
427 
428 	tz->last_temperature = tz->temperature;
429 	tz->temperature = temp;
430 
431 	trace_thermal_temperature(tz);
432 
433 	thermal_genl_sampling_temp(tz->id, temp);
434 	thermal_debug_update_temp(tz);
435 }
436 
437 static void thermal_zone_device_check(struct work_struct *work)
438 {
439 	struct thermal_zone_device *tz = container_of(work, struct
440 						      thermal_zone_device,
441 						      poll_queue.work);
442 	thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
443 }
444 
445 static void thermal_zone_device_init(struct thermal_zone_device *tz)
446 {
447 	struct thermal_instance *pos;
448 
449 	INIT_DELAYED_WORK(&tz->poll_queue, thermal_zone_device_check);
450 
451 	tz->temperature = THERMAL_TEMP_INVALID;
452 	tz->prev_low_trip = -INT_MAX;
453 	tz->prev_high_trip = INT_MAX;
454 	list_for_each_entry(pos, &tz->thermal_instances, tz_node)
455 		pos->initialized = false;
456 }
457 
458 void __thermal_zone_device_update(struct thermal_zone_device *tz,
459 				  enum thermal_notify_event event)
460 {
461 	struct thermal_trip *trip;
462 
463 	if (tz->suspended)
464 		return;
465 
466 	if (!thermal_zone_device_is_enabled(tz))
467 		return;
468 
469 	update_temperature(tz);
470 
471 	__thermal_zone_set_trips(tz);
472 
473 	tz->notify_event = event;
474 
475 	for_each_trip(tz, trip)
476 		handle_thermal_trip(tz, trip);
477 
478 	monitor_thermal_zone(tz);
479 }
480 
481 static int thermal_zone_device_set_mode(struct thermal_zone_device *tz,
482 					enum thermal_device_mode mode)
483 {
484 	int ret = 0;
485 
486 	mutex_lock(&tz->lock);
487 
488 	/* do nothing if mode isn't changing */
489 	if (mode == tz->mode) {
490 		mutex_unlock(&tz->lock);
491 
492 		return ret;
493 	}
494 
495 	if (tz->ops.change_mode)
496 		ret = tz->ops.change_mode(tz, mode);
497 
498 	if (!ret)
499 		tz->mode = mode;
500 
501 	__thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
502 
503 	mutex_unlock(&tz->lock);
504 
505 	if (mode == THERMAL_DEVICE_ENABLED)
506 		thermal_notify_tz_enable(tz);
507 	else
508 		thermal_notify_tz_disable(tz);
509 
510 	return ret;
511 }
512 
513 int thermal_zone_device_enable(struct thermal_zone_device *tz)
514 {
515 	return thermal_zone_device_set_mode(tz, THERMAL_DEVICE_ENABLED);
516 }
517 EXPORT_SYMBOL_GPL(thermal_zone_device_enable);
518 
519 int thermal_zone_device_disable(struct thermal_zone_device *tz)
520 {
521 	return thermal_zone_device_set_mode(tz, THERMAL_DEVICE_DISABLED);
522 }
523 EXPORT_SYMBOL_GPL(thermal_zone_device_disable);
524 
525 int thermal_zone_device_is_enabled(struct thermal_zone_device *tz)
526 {
527 	lockdep_assert_held(&tz->lock);
528 
529 	return tz->mode == THERMAL_DEVICE_ENABLED;
530 }
531 
532 static bool thermal_zone_is_present(struct thermal_zone_device *tz)
533 {
534 	return !list_empty(&tz->node);
535 }
536 
537 void thermal_zone_device_update(struct thermal_zone_device *tz,
538 				enum thermal_notify_event event)
539 {
540 	mutex_lock(&tz->lock);
541 	if (thermal_zone_is_present(tz))
542 		__thermal_zone_device_update(tz, event);
543 	mutex_unlock(&tz->lock);
544 }
545 EXPORT_SYMBOL_GPL(thermal_zone_device_update);
546 
547 int for_each_thermal_governor(int (*cb)(struct thermal_governor *, void *),
548 			      void *data)
549 {
550 	struct thermal_governor *gov;
551 	int ret = 0;
552 
553 	mutex_lock(&thermal_governor_lock);
554 	list_for_each_entry(gov, &thermal_governor_list, governor_list) {
555 		ret = cb(gov, data);
556 		if (ret)
557 			break;
558 	}
559 	mutex_unlock(&thermal_governor_lock);
560 
561 	return ret;
562 }
563 
564 int for_each_thermal_cooling_device(int (*cb)(struct thermal_cooling_device *,
565 					      void *), void *data)
566 {
567 	struct thermal_cooling_device *cdev;
568 	int ret = 0;
569 
570 	mutex_lock(&thermal_list_lock);
571 	list_for_each_entry(cdev, &thermal_cdev_list, node) {
572 		ret = cb(cdev, data);
573 		if (ret)
574 			break;
575 	}
576 	mutex_unlock(&thermal_list_lock);
577 
578 	return ret;
579 }
580 
581 int for_each_thermal_zone(int (*cb)(struct thermal_zone_device *, void *),
582 			  void *data)
583 {
584 	struct thermal_zone_device *tz;
585 	int ret = 0;
586 
587 	mutex_lock(&thermal_list_lock);
588 	list_for_each_entry(tz, &thermal_tz_list, node) {
589 		ret = cb(tz, data);
590 		if (ret)
591 			break;
592 	}
593 	mutex_unlock(&thermal_list_lock);
594 
595 	return ret;
596 }
597 
598 struct thermal_zone_device *thermal_zone_get_by_id(int id)
599 {
600 	struct thermal_zone_device *tz, *match = NULL;
601 
602 	mutex_lock(&thermal_list_lock);
603 	list_for_each_entry(tz, &thermal_tz_list, node) {
604 		if (tz->id == id) {
605 			match = tz;
606 			break;
607 		}
608 	}
609 	mutex_unlock(&thermal_list_lock);
610 
611 	return match;
612 }
613 
614 /*
615  * Device management section: cooling devices, zones devices, and binding
616  *
617  * Set of functions provided by the thermal core for:
618  * - cooling devices lifecycle: registration, unregistration,
619  *				binding, and unbinding.
620  * - thermal zone devices lifecycle: registration, unregistration,
621  *				     binding, and unbinding.
622  */
623 
624 /**
625  * thermal_bind_cdev_to_trip - bind a cooling device to a thermal zone
626  * @tz:		pointer to struct thermal_zone_device
627  * @trip:	trip point the cooling devices is associated with in this zone.
628  * @cdev:	pointer to struct thermal_cooling_device
629  * @upper:	the Maximum cooling state for this trip point.
630  *		THERMAL_NO_LIMIT means no upper limit,
631  *		and the cooling device can be in max_state.
632  * @lower:	the Minimum cooling state can be used for this trip point.
633  *		THERMAL_NO_LIMIT means no lower limit,
634  *		and the cooling device can be in cooling state 0.
635  * @weight:	The weight of the cooling device to be bound to the
636  *		thermal zone. Use THERMAL_WEIGHT_DEFAULT for the
637  *		default value
638  *
639  * This interface function bind a thermal cooling device to the certain trip
640  * point of a thermal zone device.
641  * This function is usually called in the thermal zone device .bind callback.
642  *
643  * Return: 0 on success, the proper error value otherwise.
644  */
645 int thermal_bind_cdev_to_trip(struct thermal_zone_device *tz,
646 				     const struct thermal_trip *trip,
647 				     struct thermal_cooling_device *cdev,
648 				     unsigned long upper, unsigned long lower,
649 				     unsigned int weight)
650 {
651 	struct thermal_instance *dev;
652 	struct thermal_instance *pos;
653 	struct thermal_zone_device *pos1;
654 	struct thermal_cooling_device *pos2;
655 	bool upper_no_limit;
656 	int result;
657 
658 	list_for_each_entry(pos1, &thermal_tz_list, node) {
659 		if (pos1 == tz)
660 			break;
661 	}
662 	list_for_each_entry(pos2, &thermal_cdev_list, node) {
663 		if (pos2 == cdev)
664 			break;
665 	}
666 
667 	if (tz != pos1 || cdev != pos2)
668 		return -EINVAL;
669 
670 	/* lower default 0, upper default max_state */
671 	lower = lower == THERMAL_NO_LIMIT ? 0 : lower;
672 
673 	if (upper == THERMAL_NO_LIMIT) {
674 		upper = cdev->max_state;
675 		upper_no_limit = true;
676 	} else {
677 		upper_no_limit = false;
678 	}
679 
680 	if (lower > upper || upper > cdev->max_state)
681 		return -EINVAL;
682 
683 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
684 	if (!dev)
685 		return -ENOMEM;
686 	dev->tz = tz;
687 	dev->cdev = cdev;
688 	dev->trip = trip;
689 	dev->upper = upper;
690 	dev->upper_no_limit = upper_no_limit;
691 	dev->lower = lower;
692 	dev->target = THERMAL_NO_TARGET;
693 	dev->weight = weight;
694 
695 	result = ida_alloc(&tz->ida, GFP_KERNEL);
696 	if (result < 0)
697 		goto free_mem;
698 
699 	dev->id = result;
700 	sprintf(dev->name, "cdev%d", dev->id);
701 	result =
702 	    sysfs_create_link(&tz->device.kobj, &cdev->device.kobj, dev->name);
703 	if (result)
704 		goto release_ida;
705 
706 	snprintf(dev->attr_name, sizeof(dev->attr_name), "cdev%d_trip_point",
707 		 dev->id);
708 	sysfs_attr_init(&dev->attr.attr);
709 	dev->attr.attr.name = dev->attr_name;
710 	dev->attr.attr.mode = 0444;
711 	dev->attr.show = trip_point_show;
712 	result = device_create_file(&tz->device, &dev->attr);
713 	if (result)
714 		goto remove_symbol_link;
715 
716 	snprintf(dev->weight_attr_name, sizeof(dev->weight_attr_name),
717 		 "cdev%d_weight", dev->id);
718 	sysfs_attr_init(&dev->weight_attr.attr);
719 	dev->weight_attr.attr.name = dev->weight_attr_name;
720 	dev->weight_attr.attr.mode = S_IWUSR | S_IRUGO;
721 	dev->weight_attr.show = weight_show;
722 	dev->weight_attr.store = weight_store;
723 	result = device_create_file(&tz->device, &dev->weight_attr);
724 	if (result)
725 		goto remove_trip_file;
726 
727 	mutex_lock(&tz->lock);
728 	mutex_lock(&cdev->lock);
729 	list_for_each_entry(pos, &tz->thermal_instances, tz_node)
730 		if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
731 			result = -EEXIST;
732 			break;
733 		}
734 	if (!result) {
735 		list_add_tail(&dev->tz_node, &tz->thermal_instances);
736 		list_add_tail(&dev->cdev_node, &cdev->thermal_instances);
737 		atomic_set(&tz->need_update, 1);
738 
739 		thermal_governor_update_tz(tz, THERMAL_TZ_BIND_CDEV);
740 	}
741 	mutex_unlock(&cdev->lock);
742 	mutex_unlock(&tz->lock);
743 
744 	if (!result)
745 		return 0;
746 
747 	device_remove_file(&tz->device, &dev->weight_attr);
748 remove_trip_file:
749 	device_remove_file(&tz->device, &dev->attr);
750 remove_symbol_link:
751 	sysfs_remove_link(&tz->device.kobj, dev->name);
752 release_ida:
753 	ida_free(&tz->ida, dev->id);
754 free_mem:
755 	kfree(dev);
756 	return result;
757 }
758 EXPORT_SYMBOL_GPL(thermal_bind_cdev_to_trip);
759 
760 int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz,
761 				     int trip_index,
762 				     struct thermal_cooling_device *cdev,
763 				     unsigned long upper, unsigned long lower,
764 				     unsigned int weight)
765 {
766 	if (trip_index < 0 || trip_index >= tz->num_trips)
767 		return -EINVAL;
768 
769 	return thermal_bind_cdev_to_trip(tz, &tz->trips[trip_index], cdev,
770 					 upper, lower, weight);
771 }
772 EXPORT_SYMBOL_GPL(thermal_zone_bind_cooling_device);
773 
774 /**
775  * thermal_unbind_cdev_from_trip - unbind a cooling device from a thermal zone.
776  * @tz:		pointer to a struct thermal_zone_device.
777  * @trip:	trip point the cooling devices is associated with in this zone.
778  * @cdev:	pointer to a struct thermal_cooling_device.
779  *
780  * This interface function unbind a thermal cooling device from the certain
781  * trip point of a thermal zone device.
782  * This function is usually called in the thermal zone device .unbind callback.
783  *
784  * Return: 0 on success, the proper error value otherwise.
785  */
786 int thermal_unbind_cdev_from_trip(struct thermal_zone_device *tz,
787 				  const struct thermal_trip *trip,
788 				  struct thermal_cooling_device *cdev)
789 {
790 	struct thermal_instance *pos, *next;
791 
792 	mutex_lock(&tz->lock);
793 	mutex_lock(&cdev->lock);
794 	list_for_each_entry_safe(pos, next, &tz->thermal_instances, tz_node) {
795 		if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
796 			list_del(&pos->tz_node);
797 			list_del(&pos->cdev_node);
798 
799 			thermal_governor_update_tz(tz, THERMAL_TZ_UNBIND_CDEV);
800 
801 			mutex_unlock(&cdev->lock);
802 			mutex_unlock(&tz->lock);
803 			goto unbind;
804 		}
805 	}
806 	mutex_unlock(&cdev->lock);
807 	mutex_unlock(&tz->lock);
808 
809 	return -ENODEV;
810 
811 unbind:
812 	device_remove_file(&tz->device, &pos->weight_attr);
813 	device_remove_file(&tz->device, &pos->attr);
814 	sysfs_remove_link(&tz->device.kobj, pos->name);
815 	ida_free(&tz->ida, pos->id);
816 	kfree(pos);
817 	return 0;
818 }
819 EXPORT_SYMBOL_GPL(thermal_unbind_cdev_from_trip);
820 
821 int thermal_zone_unbind_cooling_device(struct thermal_zone_device *tz,
822 				       int trip_index,
823 				       struct thermal_cooling_device *cdev)
824 {
825 	if (trip_index < 0 || trip_index >= tz->num_trips)
826 		return -EINVAL;
827 
828 	return thermal_unbind_cdev_from_trip(tz, &tz->trips[trip_index], cdev);
829 }
830 EXPORT_SYMBOL_GPL(thermal_zone_unbind_cooling_device);
831 
832 static void thermal_release(struct device *dev)
833 {
834 	struct thermal_zone_device *tz;
835 	struct thermal_cooling_device *cdev;
836 
837 	if (!strncmp(dev_name(dev), "thermal_zone",
838 		     sizeof("thermal_zone") - 1)) {
839 		tz = to_thermal_zone(dev);
840 		thermal_zone_destroy_device_groups(tz);
841 		mutex_destroy(&tz->lock);
842 		complete(&tz->removal);
843 	} else if (!strncmp(dev_name(dev), "cooling_device",
844 			    sizeof("cooling_device") - 1)) {
845 		cdev = to_cooling_device(dev);
846 		thermal_cooling_device_destroy_sysfs(cdev);
847 		kfree_const(cdev->type);
848 		ida_free(&thermal_cdev_ida, cdev->id);
849 		kfree(cdev);
850 	}
851 }
852 
853 static struct class *thermal_class;
854 
855 static inline
856 void print_bind_err_msg(struct thermal_zone_device *tz,
857 			struct thermal_cooling_device *cdev, int ret)
858 {
859 	dev_err(&tz->device, "binding zone %s with cdev %s failed:%d\n",
860 		tz->type, cdev->type, ret);
861 }
862 
863 static void bind_cdev(struct thermal_cooling_device *cdev)
864 {
865 	int ret;
866 	struct thermal_zone_device *pos = NULL;
867 
868 	list_for_each_entry(pos, &thermal_tz_list, node) {
869 		if (pos->ops.bind) {
870 			ret = pos->ops.bind(pos, cdev);
871 			if (ret)
872 				print_bind_err_msg(pos, cdev, ret);
873 		}
874 	}
875 }
876 
877 /**
878  * __thermal_cooling_device_register() - register a new thermal cooling device
879  * @np:		a pointer to a device tree node.
880  * @type:	the thermal cooling device type.
881  * @devdata:	device private data.
882  * @ops:		standard thermal cooling devices callbacks.
883  *
884  * This interface function adds a new thermal cooling device (fan/processor/...)
885  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
886  * to all the thermal zone devices registered at the same time.
887  * It also gives the opportunity to link the cooling device to a device tree
888  * node, so that it can be bound to a thermal zone created out of device tree.
889  *
890  * Return: a pointer to the created struct thermal_cooling_device or an
891  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
892  */
893 static struct thermal_cooling_device *
894 __thermal_cooling_device_register(struct device_node *np,
895 				  const char *type, void *devdata,
896 				  const struct thermal_cooling_device_ops *ops)
897 {
898 	struct thermal_cooling_device *cdev;
899 	struct thermal_zone_device *pos = NULL;
900 	int id, ret;
901 
902 	if (!ops || !ops->get_max_state || !ops->get_cur_state ||
903 	    !ops->set_cur_state)
904 		return ERR_PTR(-EINVAL);
905 
906 	if (!thermal_class)
907 		return ERR_PTR(-ENODEV);
908 
909 	cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
910 	if (!cdev)
911 		return ERR_PTR(-ENOMEM);
912 
913 	ret = ida_alloc(&thermal_cdev_ida, GFP_KERNEL);
914 	if (ret < 0)
915 		goto out_kfree_cdev;
916 	cdev->id = ret;
917 	id = ret;
918 
919 	cdev->type = kstrdup_const(type ? type : "", GFP_KERNEL);
920 	if (!cdev->type) {
921 		ret = -ENOMEM;
922 		goto out_ida_remove;
923 	}
924 
925 	mutex_init(&cdev->lock);
926 	INIT_LIST_HEAD(&cdev->thermal_instances);
927 	cdev->np = np;
928 	cdev->ops = ops;
929 	cdev->updated = false;
930 	cdev->device.class = thermal_class;
931 	cdev->devdata = devdata;
932 
933 	ret = cdev->ops->get_max_state(cdev, &cdev->max_state);
934 	if (ret)
935 		goto out_cdev_type;
936 
937 	thermal_cooling_device_setup_sysfs(cdev);
938 
939 	ret = dev_set_name(&cdev->device, "cooling_device%d", cdev->id);
940 	if (ret)
941 		goto out_cooling_dev;
942 
943 	ret = device_register(&cdev->device);
944 	if (ret) {
945 		/* thermal_release() handles rest of the cleanup */
946 		put_device(&cdev->device);
947 		return ERR_PTR(ret);
948 	}
949 
950 	/* Add 'this' new cdev to the global cdev list */
951 	mutex_lock(&thermal_list_lock);
952 
953 	list_add(&cdev->node, &thermal_cdev_list);
954 
955 	/* Update binding information for 'this' new cdev */
956 	bind_cdev(cdev);
957 
958 	list_for_each_entry(pos, &thermal_tz_list, node)
959 		if (atomic_cmpxchg(&pos->need_update, 1, 0))
960 			thermal_zone_device_update(pos,
961 						   THERMAL_EVENT_UNSPECIFIED);
962 
963 	mutex_unlock(&thermal_list_lock);
964 
965 	thermal_debug_cdev_add(cdev);
966 
967 	return cdev;
968 
969 out_cooling_dev:
970 	thermal_cooling_device_destroy_sysfs(cdev);
971 out_cdev_type:
972 	kfree_const(cdev->type);
973 out_ida_remove:
974 	ida_free(&thermal_cdev_ida, id);
975 out_kfree_cdev:
976 	kfree(cdev);
977 	return ERR_PTR(ret);
978 }
979 
980 /**
981  * thermal_cooling_device_register() - register a new thermal cooling device
982  * @type:	the thermal cooling device type.
983  * @devdata:	device private data.
984  * @ops:		standard thermal cooling devices callbacks.
985  *
986  * This interface function adds a new thermal cooling device (fan/processor/...)
987  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
988  * to all the thermal zone devices registered at the same time.
989  *
990  * Return: a pointer to the created struct thermal_cooling_device or an
991  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
992  */
993 struct thermal_cooling_device *
994 thermal_cooling_device_register(const char *type, void *devdata,
995 				const struct thermal_cooling_device_ops *ops)
996 {
997 	return __thermal_cooling_device_register(NULL, type, devdata, ops);
998 }
999 EXPORT_SYMBOL_GPL(thermal_cooling_device_register);
1000 
1001 /**
1002  * thermal_of_cooling_device_register() - register an OF thermal cooling device
1003  * @np:		a pointer to a device tree node.
1004  * @type:	the thermal cooling device type.
1005  * @devdata:	device private data.
1006  * @ops:		standard thermal cooling devices callbacks.
1007  *
1008  * This function will register a cooling device with device tree node reference.
1009  * This interface function adds a new thermal cooling device (fan/processor/...)
1010  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
1011  * to all the thermal zone devices registered at the same time.
1012  *
1013  * Return: a pointer to the created struct thermal_cooling_device or an
1014  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
1015  */
1016 struct thermal_cooling_device *
1017 thermal_of_cooling_device_register(struct device_node *np,
1018 				   const char *type, void *devdata,
1019 				   const struct thermal_cooling_device_ops *ops)
1020 {
1021 	return __thermal_cooling_device_register(np, type, devdata, ops);
1022 }
1023 EXPORT_SYMBOL_GPL(thermal_of_cooling_device_register);
1024 
1025 static void thermal_cooling_device_release(struct device *dev, void *res)
1026 {
1027 	thermal_cooling_device_unregister(
1028 				*(struct thermal_cooling_device **)res);
1029 }
1030 
1031 /**
1032  * devm_thermal_of_cooling_device_register() - register an OF thermal cooling
1033  *					       device
1034  * @dev:	a valid struct device pointer of a sensor device.
1035  * @np:		a pointer to a device tree node.
1036  * @type:	the thermal cooling device type.
1037  * @devdata:	device private data.
1038  * @ops:	standard thermal cooling devices callbacks.
1039  *
1040  * This function will register a cooling device with device tree node reference.
1041  * This interface function adds a new thermal cooling device (fan/processor/...)
1042  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
1043  * to all the thermal zone devices registered at the same time.
1044  *
1045  * Return: a pointer to the created struct thermal_cooling_device or an
1046  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
1047  */
1048 struct thermal_cooling_device *
1049 devm_thermal_of_cooling_device_register(struct device *dev,
1050 				struct device_node *np,
1051 				char *type, void *devdata,
1052 				const struct thermal_cooling_device_ops *ops)
1053 {
1054 	struct thermal_cooling_device **ptr, *tcd;
1055 
1056 	ptr = devres_alloc(thermal_cooling_device_release, sizeof(*ptr),
1057 			   GFP_KERNEL);
1058 	if (!ptr)
1059 		return ERR_PTR(-ENOMEM);
1060 
1061 	tcd = __thermal_cooling_device_register(np, type, devdata, ops);
1062 	if (IS_ERR(tcd)) {
1063 		devres_free(ptr);
1064 		return tcd;
1065 	}
1066 
1067 	*ptr = tcd;
1068 	devres_add(dev, ptr);
1069 
1070 	return tcd;
1071 }
1072 EXPORT_SYMBOL_GPL(devm_thermal_of_cooling_device_register);
1073 
1074 static bool thermal_cooling_device_present(struct thermal_cooling_device *cdev)
1075 {
1076 	struct thermal_cooling_device *pos = NULL;
1077 
1078 	list_for_each_entry(pos, &thermal_cdev_list, node) {
1079 		if (pos == cdev)
1080 			return true;
1081 	}
1082 
1083 	return false;
1084 }
1085 
1086 /**
1087  * thermal_cooling_device_update - Update a cooling device object
1088  * @cdev: Target cooling device.
1089  *
1090  * Update @cdev to reflect a change of the underlying hardware or platform.
1091  *
1092  * Must be called when the maximum cooling state of @cdev becomes invalid and so
1093  * its .get_max_state() callback needs to be run to produce the new maximum
1094  * cooling state value.
1095  */
1096 void thermal_cooling_device_update(struct thermal_cooling_device *cdev)
1097 {
1098 	struct thermal_instance *ti;
1099 	unsigned long state;
1100 
1101 	if (IS_ERR_OR_NULL(cdev))
1102 		return;
1103 
1104 	/*
1105 	 * Hold thermal_list_lock throughout the update to prevent the device
1106 	 * from going away while being updated.
1107 	 */
1108 	mutex_lock(&thermal_list_lock);
1109 
1110 	if (!thermal_cooling_device_present(cdev))
1111 		goto unlock_list;
1112 
1113 	/*
1114 	 * Update under the cdev lock to prevent the state from being set beyond
1115 	 * the new limit concurrently.
1116 	 */
1117 	mutex_lock(&cdev->lock);
1118 
1119 	if (cdev->ops->get_max_state(cdev, &cdev->max_state))
1120 		goto unlock;
1121 
1122 	thermal_cooling_device_stats_reinit(cdev);
1123 
1124 	list_for_each_entry(ti, &cdev->thermal_instances, cdev_node) {
1125 		if (ti->upper == cdev->max_state)
1126 			continue;
1127 
1128 		if (ti->upper < cdev->max_state) {
1129 			if (ti->upper_no_limit)
1130 				ti->upper = cdev->max_state;
1131 
1132 			continue;
1133 		}
1134 
1135 		ti->upper = cdev->max_state;
1136 		if (ti->lower > ti->upper)
1137 			ti->lower = ti->upper;
1138 
1139 		if (ti->target == THERMAL_NO_TARGET)
1140 			continue;
1141 
1142 		if (ti->target > ti->upper)
1143 			ti->target = ti->upper;
1144 	}
1145 
1146 	if (cdev->ops->get_cur_state(cdev, &state) || state > cdev->max_state)
1147 		goto unlock;
1148 
1149 	thermal_cooling_device_stats_update(cdev, state);
1150 
1151 unlock:
1152 	mutex_unlock(&cdev->lock);
1153 
1154 unlock_list:
1155 	mutex_unlock(&thermal_list_lock);
1156 }
1157 EXPORT_SYMBOL_GPL(thermal_cooling_device_update);
1158 
1159 /**
1160  * thermal_cooling_device_unregister - removes a thermal cooling device
1161  * @cdev:	the thermal cooling device to remove.
1162  *
1163  * thermal_cooling_device_unregister() must be called when a registered
1164  * thermal cooling device is no longer needed.
1165  */
1166 void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev)
1167 {
1168 	struct thermal_zone_device *tz;
1169 
1170 	if (!cdev)
1171 		return;
1172 
1173 	thermal_debug_cdev_remove(cdev);
1174 
1175 	mutex_lock(&thermal_list_lock);
1176 
1177 	if (!thermal_cooling_device_present(cdev)) {
1178 		mutex_unlock(&thermal_list_lock);
1179 		return;
1180 	}
1181 
1182 	list_del(&cdev->node);
1183 
1184 	/* Unbind all thermal zones associated with 'this' cdev */
1185 	list_for_each_entry(tz, &thermal_tz_list, node) {
1186 		if (tz->ops.unbind)
1187 			tz->ops.unbind(tz, cdev);
1188 	}
1189 
1190 	mutex_unlock(&thermal_list_lock);
1191 
1192 	device_unregister(&cdev->device);
1193 }
1194 EXPORT_SYMBOL_GPL(thermal_cooling_device_unregister);
1195 
1196 static void bind_tz(struct thermal_zone_device *tz)
1197 {
1198 	int ret;
1199 	struct thermal_cooling_device *pos = NULL;
1200 
1201 	if (!tz->ops.bind)
1202 		return;
1203 
1204 	mutex_lock(&thermal_list_lock);
1205 
1206 	list_for_each_entry(pos, &thermal_cdev_list, node) {
1207 		ret = tz->ops.bind(tz, pos);
1208 		if (ret)
1209 			print_bind_err_msg(tz, pos, ret);
1210 	}
1211 
1212 	mutex_unlock(&thermal_list_lock);
1213 }
1214 
1215 static void thermal_set_delay_jiffies(unsigned long *delay_jiffies, int delay_ms)
1216 {
1217 	*delay_jiffies = msecs_to_jiffies(delay_ms);
1218 	if (delay_ms > 1000)
1219 		*delay_jiffies = round_jiffies(*delay_jiffies);
1220 }
1221 
1222 int thermal_zone_get_crit_temp(struct thermal_zone_device *tz, int *temp)
1223 {
1224 	int i, ret = -EINVAL;
1225 
1226 	if (tz->ops.get_crit_temp)
1227 		return tz->ops.get_crit_temp(tz, temp);
1228 
1229 	mutex_lock(&tz->lock);
1230 
1231 	for (i = 0; i < tz->num_trips; i++) {
1232 		if (tz->trips[i].type == THERMAL_TRIP_CRITICAL) {
1233 			*temp = tz->trips[i].temperature;
1234 			ret = 0;
1235 			break;
1236 		}
1237 	}
1238 
1239 	mutex_unlock(&tz->lock);
1240 
1241 	return ret;
1242 }
1243 EXPORT_SYMBOL_GPL(thermal_zone_get_crit_temp);
1244 
1245 /**
1246  * thermal_zone_device_register_with_trips() - register a new thermal zone device
1247  * @type:	the thermal zone device type
1248  * @trips:	a pointer to an array of thermal trips
1249  * @num_trips:	the number of trip points the thermal zone support
1250  * @devdata:	private device data
1251  * @ops:	standard thermal zone device callbacks
1252  * @tzp:	thermal zone platform parameters
1253  * @passive_delay: number of milliseconds to wait between polls when
1254  *		   performing passive cooling
1255  * @polling_delay: number of milliseconds to wait between polls when checking
1256  *		   whether trip points have been crossed (0 for interrupt
1257  *		   driven systems)
1258  *
1259  * This interface function adds a new thermal zone device (sensor) to
1260  * /sys/class/thermal folder as thermal_zone[0-*]. It tries to bind all the
1261  * thermal cooling devices registered at the same time.
1262  * thermal_zone_device_unregister() must be called when the device is no
1263  * longer needed. The passive cooling depends on the .get_trend() return value.
1264  *
1265  * Return: a pointer to the created struct thermal_zone_device or an
1266  * in case of error, an ERR_PTR. Caller must check return value with
1267  * IS_ERR*() helpers.
1268  */
1269 struct thermal_zone_device *
1270 thermal_zone_device_register_with_trips(const char *type,
1271 					const struct thermal_trip *trips,
1272 					int num_trips, void *devdata,
1273 					const struct thermal_zone_device_ops *ops,
1274 					const struct thermal_zone_params *tzp,
1275 					int passive_delay, int polling_delay)
1276 {
1277 	struct thermal_zone_device *tz;
1278 	int id;
1279 	int result;
1280 	struct thermal_governor *governor;
1281 
1282 	if (!type || strlen(type) == 0) {
1283 		pr_err("No thermal zone type defined\n");
1284 		return ERR_PTR(-EINVAL);
1285 	}
1286 
1287 	if (strlen(type) >= THERMAL_NAME_LENGTH) {
1288 		pr_err("Thermal zone name (%s) too long, should be under %d chars\n",
1289 		       type, THERMAL_NAME_LENGTH);
1290 		return ERR_PTR(-EINVAL);
1291 	}
1292 
1293 	if (num_trips < 0) {
1294 		pr_err("Incorrect number of thermal trips\n");
1295 		return ERR_PTR(-EINVAL);
1296 	}
1297 
1298 	if (!ops || !ops->get_temp) {
1299 		pr_err("Thermal zone device ops not defined\n");
1300 		return ERR_PTR(-EINVAL);
1301 	}
1302 
1303 	if (num_trips > 0 && !trips)
1304 		return ERR_PTR(-EINVAL);
1305 
1306 	if (!thermal_class)
1307 		return ERR_PTR(-ENODEV);
1308 
1309 	tz = kzalloc(struct_size(tz, trips, num_trips), GFP_KERNEL);
1310 	if (!tz)
1311 		return ERR_PTR(-ENOMEM);
1312 
1313 	if (tzp) {
1314 		tz->tzp = kmemdup(tzp, sizeof(*tzp), GFP_KERNEL);
1315 		if (!tz->tzp) {
1316 			result = -ENOMEM;
1317 			goto free_tz;
1318 		}
1319 	}
1320 
1321 	INIT_LIST_HEAD(&tz->thermal_instances);
1322 	INIT_LIST_HEAD(&tz->node);
1323 	ida_init(&tz->ida);
1324 	mutex_init(&tz->lock);
1325 	init_completion(&tz->removal);
1326 	id = ida_alloc(&thermal_tz_ida, GFP_KERNEL);
1327 	if (id < 0) {
1328 		result = id;
1329 		goto free_tzp;
1330 	}
1331 
1332 	tz->id = id;
1333 	strscpy(tz->type, type, sizeof(tz->type));
1334 
1335 	tz->ops = *ops;
1336 	if (!tz->ops.critical)
1337 		tz->ops.critical = thermal_zone_device_critical;
1338 
1339 	tz->device.class = thermal_class;
1340 	tz->devdata = devdata;
1341 	tz->num_trips = num_trips;
1342 	memcpy(tz->trips, trips, num_trips * sizeof(*trips));
1343 
1344 	thermal_set_delay_jiffies(&tz->passive_delay_jiffies, passive_delay);
1345 	thermal_set_delay_jiffies(&tz->polling_delay_jiffies, polling_delay);
1346 
1347 	/* sys I/F */
1348 	/* Add nodes that are always present via .groups */
1349 	result = thermal_zone_create_device_groups(tz);
1350 	if (result)
1351 		goto remove_id;
1352 
1353 	/* A new thermal zone needs to be updated anyway. */
1354 	atomic_set(&tz->need_update, 1);
1355 
1356 	result = dev_set_name(&tz->device, "thermal_zone%d", tz->id);
1357 	if (result) {
1358 		thermal_zone_destroy_device_groups(tz);
1359 		goto remove_id;
1360 	}
1361 	result = device_register(&tz->device);
1362 	if (result)
1363 		goto release_device;
1364 
1365 	/* Update 'this' zone's governor information */
1366 	mutex_lock(&thermal_governor_lock);
1367 
1368 	if (tz->tzp)
1369 		governor = __find_governor(tz->tzp->governor_name);
1370 	else
1371 		governor = def_governor;
1372 
1373 	result = thermal_set_governor(tz, governor);
1374 	if (result) {
1375 		mutex_unlock(&thermal_governor_lock);
1376 		goto unregister;
1377 	}
1378 
1379 	mutex_unlock(&thermal_governor_lock);
1380 
1381 	if (!tz->tzp || !tz->tzp->no_hwmon) {
1382 		result = thermal_add_hwmon_sysfs(tz);
1383 		if (result)
1384 			goto unregister;
1385 	}
1386 
1387 	mutex_lock(&thermal_list_lock);
1388 	mutex_lock(&tz->lock);
1389 	list_add_tail(&tz->node, &thermal_tz_list);
1390 	mutex_unlock(&tz->lock);
1391 	mutex_unlock(&thermal_list_lock);
1392 
1393 	/* Bind cooling devices for this zone */
1394 	bind_tz(tz);
1395 
1396 	thermal_zone_device_init(tz);
1397 	/* Update the new thermal zone and mark it as already updated. */
1398 	if (atomic_cmpxchg(&tz->need_update, 1, 0))
1399 		thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
1400 
1401 	thermal_notify_tz_create(tz);
1402 
1403 	thermal_debug_tz_add(tz);
1404 
1405 	return tz;
1406 
1407 unregister:
1408 	device_del(&tz->device);
1409 release_device:
1410 	put_device(&tz->device);
1411 remove_id:
1412 	ida_free(&thermal_tz_ida, id);
1413 free_tzp:
1414 	kfree(tz->tzp);
1415 free_tz:
1416 	kfree(tz);
1417 	return ERR_PTR(result);
1418 }
1419 EXPORT_SYMBOL_GPL(thermal_zone_device_register_with_trips);
1420 
1421 struct thermal_zone_device *thermal_tripless_zone_device_register(
1422 					const char *type,
1423 					void *devdata,
1424 					const struct thermal_zone_device_ops *ops,
1425 					const struct thermal_zone_params *tzp)
1426 {
1427 	return thermal_zone_device_register_with_trips(type, NULL, 0, devdata,
1428 						       ops, tzp, 0, 0);
1429 }
1430 EXPORT_SYMBOL_GPL(thermal_tripless_zone_device_register);
1431 
1432 void *thermal_zone_device_priv(struct thermal_zone_device *tzd)
1433 {
1434 	return tzd->devdata;
1435 }
1436 EXPORT_SYMBOL_GPL(thermal_zone_device_priv);
1437 
1438 const char *thermal_zone_device_type(struct thermal_zone_device *tzd)
1439 {
1440 	return tzd->type;
1441 }
1442 EXPORT_SYMBOL_GPL(thermal_zone_device_type);
1443 
1444 int thermal_zone_device_id(struct thermal_zone_device *tzd)
1445 {
1446 	return tzd->id;
1447 }
1448 EXPORT_SYMBOL_GPL(thermal_zone_device_id);
1449 
1450 struct device *thermal_zone_device(struct thermal_zone_device *tzd)
1451 {
1452 	return &tzd->device;
1453 }
1454 EXPORT_SYMBOL_GPL(thermal_zone_device);
1455 
1456 /**
1457  * thermal_zone_device_unregister - removes the registered thermal zone device
1458  * @tz: the thermal zone device to remove
1459  */
1460 void thermal_zone_device_unregister(struct thermal_zone_device *tz)
1461 {
1462 	struct thermal_cooling_device *cdev;
1463 	struct thermal_zone_device *pos = NULL;
1464 
1465 	if (!tz)
1466 		return;
1467 
1468 	thermal_debug_tz_remove(tz);
1469 
1470 	mutex_lock(&thermal_list_lock);
1471 	list_for_each_entry(pos, &thermal_tz_list, node)
1472 		if (pos == tz)
1473 			break;
1474 	if (pos != tz) {
1475 		/* thermal zone device not found */
1476 		mutex_unlock(&thermal_list_lock);
1477 		return;
1478 	}
1479 
1480 	mutex_lock(&tz->lock);
1481 	list_del(&tz->node);
1482 	mutex_unlock(&tz->lock);
1483 
1484 	/* Unbind all cdevs associated with 'this' thermal zone */
1485 	list_for_each_entry(cdev, &thermal_cdev_list, node)
1486 		if (tz->ops.unbind)
1487 			tz->ops.unbind(tz, cdev);
1488 
1489 	mutex_unlock(&thermal_list_lock);
1490 
1491 	cancel_delayed_work_sync(&tz->poll_queue);
1492 
1493 	thermal_set_governor(tz, NULL);
1494 
1495 	thermal_remove_hwmon_sysfs(tz);
1496 	ida_free(&thermal_tz_ida, tz->id);
1497 	ida_destroy(&tz->ida);
1498 
1499 	device_del(&tz->device);
1500 
1501 	kfree(tz->tzp);
1502 
1503 	put_device(&tz->device);
1504 
1505 	thermal_notify_tz_delete(tz);
1506 
1507 	wait_for_completion(&tz->removal);
1508 	kfree(tz);
1509 }
1510 EXPORT_SYMBOL_GPL(thermal_zone_device_unregister);
1511 
1512 /**
1513  * thermal_zone_get_zone_by_name() - search for a zone and returns its ref
1514  * @name: thermal zone name to fetch the temperature
1515  *
1516  * When only one zone is found with the passed name, returns a reference to it.
1517  *
1518  * Return: On success returns a reference to an unique thermal zone with
1519  * matching name equals to @name, an ERR_PTR otherwise (-EINVAL for invalid
1520  * paramenters, -ENODEV for not found and -EEXIST for multiple matches).
1521  */
1522 struct thermal_zone_device *thermal_zone_get_zone_by_name(const char *name)
1523 {
1524 	struct thermal_zone_device *pos = NULL, *ref = ERR_PTR(-EINVAL);
1525 	unsigned int found = 0;
1526 
1527 	if (!name)
1528 		goto exit;
1529 
1530 	mutex_lock(&thermal_list_lock);
1531 	list_for_each_entry(pos, &thermal_tz_list, node)
1532 		if (!strncasecmp(name, pos->type, THERMAL_NAME_LENGTH)) {
1533 			found++;
1534 			ref = pos;
1535 		}
1536 	mutex_unlock(&thermal_list_lock);
1537 
1538 	/* nothing has been found, thus an error code for it */
1539 	if (found == 0)
1540 		ref = ERR_PTR(-ENODEV);
1541 	else if (found > 1)
1542 	/* Success only when an unique zone is found */
1543 		ref = ERR_PTR(-EEXIST);
1544 
1545 exit:
1546 	return ref;
1547 }
1548 EXPORT_SYMBOL_GPL(thermal_zone_get_zone_by_name);
1549 
1550 static void thermal_zone_device_resume(struct work_struct *work)
1551 {
1552 	struct thermal_zone_device *tz;
1553 
1554 	tz = container_of(work, struct thermal_zone_device, poll_queue.work);
1555 
1556 	mutex_lock(&tz->lock);
1557 
1558 	tz->suspended = false;
1559 
1560 	thermal_zone_device_init(tz);
1561 	__thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
1562 
1563 	mutex_unlock(&tz->lock);
1564 }
1565 
1566 static int thermal_pm_notify(struct notifier_block *nb,
1567 			     unsigned long mode, void *_unused)
1568 {
1569 	struct thermal_zone_device *tz;
1570 
1571 	switch (mode) {
1572 	case PM_HIBERNATION_PREPARE:
1573 	case PM_RESTORE_PREPARE:
1574 	case PM_SUSPEND_PREPARE:
1575 		mutex_lock(&thermal_list_lock);
1576 
1577 		list_for_each_entry(tz, &thermal_tz_list, node) {
1578 			mutex_lock(&tz->lock);
1579 
1580 			tz->suspended = true;
1581 
1582 			mutex_unlock(&tz->lock);
1583 		}
1584 
1585 		mutex_unlock(&thermal_list_lock);
1586 		break;
1587 	case PM_POST_HIBERNATION:
1588 	case PM_POST_RESTORE:
1589 	case PM_POST_SUSPEND:
1590 		mutex_lock(&thermal_list_lock);
1591 
1592 		list_for_each_entry(tz, &thermal_tz_list, node) {
1593 			mutex_lock(&tz->lock);
1594 
1595 			cancel_delayed_work(&tz->poll_queue);
1596 
1597 			/*
1598 			 * Replace the work function with the resume one, which
1599 			 * will restore the original work function and schedule
1600 			 * the polling work if needed.
1601 			 */
1602 			INIT_DELAYED_WORK(&tz->poll_queue,
1603 					  thermal_zone_device_resume);
1604 			/* Queue up the work without a delay. */
1605 			mod_delayed_work(system_freezable_power_efficient_wq,
1606 					 &tz->poll_queue, 0);
1607 
1608 			mutex_unlock(&tz->lock);
1609 		}
1610 
1611 		mutex_unlock(&thermal_list_lock);
1612 		break;
1613 	default:
1614 		break;
1615 	}
1616 	return 0;
1617 }
1618 
1619 static struct notifier_block thermal_pm_nb = {
1620 	.notifier_call = thermal_pm_notify,
1621 };
1622 
1623 static int __init thermal_init(void)
1624 {
1625 	int result;
1626 
1627 	thermal_debug_init();
1628 
1629 	result = thermal_netlink_init();
1630 	if (result)
1631 		goto error;
1632 
1633 	result = thermal_register_governors();
1634 	if (result)
1635 		goto unregister_netlink;
1636 
1637 	thermal_class = kzalloc(sizeof(*thermal_class), GFP_KERNEL);
1638 	if (!thermal_class) {
1639 		result = -ENOMEM;
1640 		goto unregister_governors;
1641 	}
1642 
1643 	thermal_class->name = "thermal";
1644 	thermal_class->dev_release = thermal_release;
1645 
1646 	result = class_register(thermal_class);
1647 	if (result) {
1648 		kfree(thermal_class);
1649 		thermal_class = NULL;
1650 		goto unregister_governors;
1651 	}
1652 
1653 	result = register_pm_notifier(&thermal_pm_nb);
1654 	if (result)
1655 		pr_warn("Thermal: Can not register suspend notifier, return %d\n",
1656 			result);
1657 
1658 	return 0;
1659 
1660 unregister_governors:
1661 	thermal_unregister_governors();
1662 unregister_netlink:
1663 	thermal_netlink_exit();
1664 error:
1665 	mutex_destroy(&thermal_list_lock);
1666 	mutex_destroy(&thermal_governor_lock);
1667 	return result;
1668 }
1669 postcore_initcall(thermal_init);
1670