xref: /linux/drivers/thermal/thermal_core.c (revision 26fbb4c8c7c3ee9a4c3b4de555a8587b5a19154e)
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 <trace/events/thermal.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 static DEFINE_MUTEX(poweroff_lock);
40 
41 static atomic_t in_suspend;
42 static bool power_off_triggered;
43 
44 static struct thermal_governor *def_governor;
45 
46 /*
47  * Governor section: set of functions to handle thermal governors
48  *
49  * Functions to help in the life cycle of thermal governors within
50  * the thermal core and by the thermal governor code.
51  */
52 
53 static struct thermal_governor *__find_governor(const char *name)
54 {
55 	struct thermal_governor *pos;
56 
57 	if (!name || !name[0])
58 		return def_governor;
59 
60 	list_for_each_entry(pos, &thermal_governor_list, governor_list)
61 		if (!strncasecmp(name, pos->name, THERMAL_NAME_LENGTH))
62 			return pos;
63 
64 	return NULL;
65 }
66 
67 /**
68  * bind_previous_governor() - bind the previous governor of the thermal zone
69  * @tz:		a valid pointer to a struct thermal_zone_device
70  * @failed_gov_name:	the name of the governor that failed to register
71  *
72  * Register the previous governor of the thermal zone after a new
73  * governor has failed to be bound.
74  */
75 static void bind_previous_governor(struct thermal_zone_device *tz,
76 				   const char *failed_gov_name)
77 {
78 	if (tz->governor && tz->governor->bind_to_tz) {
79 		if (tz->governor->bind_to_tz(tz)) {
80 			dev_err(&tz->device,
81 				"governor %s failed to bind and the previous one (%s) failed to bind again, thermal zone %s has no governor\n",
82 				failed_gov_name, tz->governor->name, tz->type);
83 			tz->governor = NULL;
84 		}
85 	}
86 }
87 
88 /**
89  * thermal_set_governor() - Switch to another governor
90  * @tz:		a valid pointer to a struct thermal_zone_device
91  * @new_gov:	pointer to the new governor
92  *
93  * Change the governor of thermal zone @tz.
94  *
95  * Return: 0 on success, an error if the new governor's bind_to_tz() failed.
96  */
97 static int thermal_set_governor(struct thermal_zone_device *tz,
98 				struct thermal_governor *new_gov)
99 {
100 	int ret = 0;
101 
102 	if (tz->governor && tz->governor->unbind_from_tz)
103 		tz->governor->unbind_from_tz(tz);
104 
105 	if (new_gov && new_gov->bind_to_tz) {
106 		ret = new_gov->bind_to_tz(tz);
107 		if (ret) {
108 			bind_previous_governor(tz, new_gov->name);
109 
110 			return ret;
111 		}
112 	}
113 
114 	tz->governor = new_gov;
115 
116 	return ret;
117 }
118 
119 int thermal_register_governor(struct thermal_governor *governor)
120 {
121 	int err;
122 	const char *name;
123 	struct thermal_zone_device *pos;
124 
125 	if (!governor)
126 		return -EINVAL;
127 
128 	mutex_lock(&thermal_governor_lock);
129 
130 	err = -EBUSY;
131 	if (!__find_governor(governor->name)) {
132 		bool match_default;
133 
134 		err = 0;
135 		list_add(&governor->governor_list, &thermal_governor_list);
136 		match_default = !strncmp(governor->name,
137 					 DEFAULT_THERMAL_GOVERNOR,
138 					 THERMAL_NAME_LENGTH);
139 
140 		if (!def_governor && match_default)
141 			def_governor = governor;
142 	}
143 
144 	mutex_lock(&thermal_list_lock);
145 
146 	list_for_each_entry(pos, &thermal_tz_list, node) {
147 		/*
148 		 * only thermal zones with specified tz->tzp->governor_name
149 		 * may run with tz->govenor unset
150 		 */
151 		if (pos->governor)
152 			continue;
153 
154 		name = pos->tzp->governor_name;
155 
156 		if (!strncasecmp(name, governor->name, THERMAL_NAME_LENGTH)) {
157 			int ret;
158 
159 			ret = thermal_set_governor(pos, governor);
160 			if (ret)
161 				dev_err(&pos->device,
162 					"Failed to set governor %s for thermal zone %s: %d\n",
163 					governor->name, pos->type, ret);
164 		}
165 	}
166 
167 	mutex_unlock(&thermal_list_lock);
168 	mutex_unlock(&thermal_governor_lock);
169 
170 	return err;
171 }
172 
173 void thermal_unregister_governor(struct thermal_governor *governor)
174 {
175 	struct thermal_zone_device *pos;
176 
177 	if (!governor)
178 		return;
179 
180 	mutex_lock(&thermal_governor_lock);
181 
182 	if (!__find_governor(governor->name))
183 		goto exit;
184 
185 	mutex_lock(&thermal_list_lock);
186 
187 	list_for_each_entry(pos, &thermal_tz_list, node) {
188 		if (!strncasecmp(pos->governor->name, governor->name,
189 				 THERMAL_NAME_LENGTH))
190 			thermal_set_governor(pos, NULL);
191 	}
192 
193 	mutex_unlock(&thermal_list_lock);
194 	list_del(&governor->governor_list);
195 exit:
196 	mutex_unlock(&thermal_governor_lock);
197 }
198 
199 int thermal_zone_device_set_policy(struct thermal_zone_device *tz,
200 				   char *policy)
201 {
202 	struct thermal_governor *gov;
203 	int ret = -EINVAL;
204 
205 	mutex_lock(&thermal_governor_lock);
206 	mutex_lock(&tz->lock);
207 
208 	gov = __find_governor(strim(policy));
209 	if (!gov)
210 		goto exit;
211 
212 	ret = thermal_set_governor(tz, gov);
213 
214 exit:
215 	mutex_unlock(&tz->lock);
216 	mutex_unlock(&thermal_governor_lock);
217 
218 	thermal_notify_tz_gov_change(tz->id, policy);
219 
220 	return ret;
221 }
222 
223 int thermal_build_list_of_policies(char *buf)
224 {
225 	struct thermal_governor *pos;
226 	ssize_t count = 0;
227 	ssize_t size = PAGE_SIZE;
228 
229 	mutex_lock(&thermal_governor_lock);
230 
231 	list_for_each_entry(pos, &thermal_governor_list, governor_list) {
232 		size = PAGE_SIZE - count;
233 		count += scnprintf(buf + count, size, "%s ", pos->name);
234 	}
235 	count += scnprintf(buf + count, size, "\n");
236 
237 	mutex_unlock(&thermal_governor_lock);
238 
239 	return count;
240 }
241 
242 static void __init thermal_unregister_governors(void)
243 {
244 	struct thermal_governor **governor;
245 
246 	for_each_governor_table(governor)
247 		thermal_unregister_governor(*governor);
248 }
249 
250 static int __init thermal_register_governors(void)
251 {
252 	int ret = 0;
253 	struct thermal_governor **governor;
254 
255 	for_each_governor_table(governor) {
256 		ret = thermal_register_governor(*governor);
257 		if (ret) {
258 			pr_err("Failed to register governor: '%s'",
259 			       (*governor)->name);
260 			break;
261 		}
262 
263 		pr_info("Registered thermal governor '%s'",
264 			(*governor)->name);
265 	}
266 
267 	if (ret) {
268 		struct thermal_governor **gov;
269 
270 		for_each_governor_table(gov) {
271 			if (gov == governor)
272 				break;
273 			thermal_unregister_governor(*gov);
274 		}
275 	}
276 
277 	return ret;
278 }
279 
280 /*
281  * Zone update section: main control loop applied to each zone while monitoring
282  *
283  * in polling mode. The monitoring is done using a workqueue.
284  * Same update may be done on a zone by calling thermal_zone_device_update().
285  *
286  * An update means:
287  * - Non-critical trips will invoke the governor responsible for that zone;
288  * - Hot trips will produce a notification to userspace;
289  * - Critical trip point will cause a system shutdown.
290  */
291 static void thermal_zone_device_set_polling(struct thermal_zone_device *tz,
292 					    int delay)
293 {
294 	if (delay > 1000)
295 		mod_delayed_work(system_freezable_power_efficient_wq,
296 				 &tz->poll_queue,
297 				 round_jiffies(msecs_to_jiffies(delay)));
298 	else if (delay)
299 		mod_delayed_work(system_freezable_power_efficient_wq,
300 				 &tz->poll_queue,
301 				 msecs_to_jiffies(delay));
302 	else
303 		cancel_delayed_work(&tz->poll_queue);
304 }
305 
306 static inline bool should_stop_polling(struct thermal_zone_device *tz)
307 {
308 	return !thermal_zone_device_is_enabled(tz);
309 }
310 
311 static void monitor_thermal_zone(struct thermal_zone_device *tz)
312 {
313 	bool stop;
314 
315 	stop = should_stop_polling(tz);
316 
317 	mutex_lock(&tz->lock);
318 
319 	if (!stop && tz->passive)
320 		thermal_zone_device_set_polling(tz, tz->passive_delay);
321 	else if (!stop && tz->polling_delay)
322 		thermal_zone_device_set_polling(tz, tz->polling_delay);
323 	else
324 		thermal_zone_device_set_polling(tz, 0);
325 
326 	mutex_unlock(&tz->lock);
327 }
328 
329 static void handle_non_critical_trips(struct thermal_zone_device *tz, int trip)
330 {
331 	tz->governor ? tz->governor->throttle(tz, trip) :
332 		       def_governor->throttle(tz, trip);
333 }
334 
335 /**
336  * thermal_emergency_poweroff_func - emergency poweroff work after a known delay
337  * @work: work_struct associated with the emergency poweroff function
338  *
339  * This function is called in very critical situations to force
340  * a kernel poweroff after a configurable timeout value.
341  */
342 static void thermal_emergency_poweroff_func(struct work_struct *work)
343 {
344 	/*
345 	 * We have reached here after the emergency thermal shutdown
346 	 * Waiting period has expired. This means orderly_poweroff has
347 	 * not been able to shut off the system for some reason.
348 	 * Try to shut down the system immediately using kernel_power_off
349 	 * if populated
350 	 */
351 	WARN(1, "Attempting kernel_power_off: Temperature too high\n");
352 	kernel_power_off();
353 
354 	/*
355 	 * Worst of the worst case trigger emergency restart
356 	 */
357 	WARN(1, "Attempting emergency_restart: Temperature too high\n");
358 	emergency_restart();
359 }
360 
361 static DECLARE_DELAYED_WORK(thermal_emergency_poweroff_work,
362 			    thermal_emergency_poweroff_func);
363 
364 /**
365  * thermal_emergency_poweroff - Trigger an emergency system poweroff
366  *
367  * This may be called from any critical situation to trigger a system shutdown
368  * after a known period of time. By default this is not scheduled.
369  */
370 static void thermal_emergency_poweroff(void)
371 {
372 	int poweroff_delay_ms = CONFIG_THERMAL_EMERGENCY_POWEROFF_DELAY_MS;
373 	/*
374 	 * poweroff_delay_ms must be a carefully profiled positive value.
375 	 * Its a must for thermal_emergency_poweroff_work to be scheduled
376 	 */
377 	if (poweroff_delay_ms <= 0)
378 		return;
379 	schedule_delayed_work(&thermal_emergency_poweroff_work,
380 			      msecs_to_jiffies(poweroff_delay_ms));
381 }
382 
383 void thermal_zone_device_critical(struct thermal_zone_device *tz)
384 {
385 	dev_emerg(&tz->device, "%s: critical temperature reached, "
386 		  "shutting down\n", tz->type);
387 
388 	mutex_lock(&poweroff_lock);
389 	if (!power_off_triggered) {
390 		/*
391 		 * Queue a backup emergency shutdown in the event of
392 		 * orderly_poweroff failure
393 		 */
394 		thermal_emergency_poweroff();
395 		orderly_poweroff(true);
396 		power_off_triggered = true;
397 	}
398 	mutex_unlock(&poweroff_lock);
399 }
400 EXPORT_SYMBOL(thermal_zone_device_critical);
401 
402 static void handle_critical_trips(struct thermal_zone_device *tz,
403 				  int trip, enum thermal_trip_type trip_type)
404 {
405 	int trip_temp;
406 
407 	tz->ops->get_trip_temp(tz, trip, &trip_temp);
408 
409 	/* If we have not crossed the trip_temp, we do not care. */
410 	if (trip_temp <= 0 || tz->temperature < trip_temp)
411 		return;
412 
413 	trace_thermal_zone_trip(tz, trip, trip_type);
414 
415 	if (tz->ops->notify)
416 		tz->ops->notify(tz, trip, trip_type);
417 
418 	if (trip_type == THERMAL_TRIP_HOT && tz->ops->hot)
419 		tz->ops->hot(tz);
420 	else if (trip_type == THERMAL_TRIP_CRITICAL)
421 		tz->ops->critical(tz);
422 }
423 
424 static void handle_thermal_trip(struct thermal_zone_device *tz, int trip)
425 {
426 	enum thermal_trip_type type;
427 	int trip_temp, hyst = 0;
428 
429 	/* Ignore disabled trip points */
430 	if (test_bit(trip, &tz->trips_disabled))
431 		return;
432 
433 	tz->ops->get_trip_temp(tz, trip, &trip_temp);
434 	tz->ops->get_trip_type(tz, trip, &type);
435 	if (tz->ops->get_trip_hyst)
436 		tz->ops->get_trip_hyst(tz, trip, &hyst);
437 
438 	if (tz->last_temperature != THERMAL_TEMP_INVALID) {
439 		if (tz->last_temperature < trip_temp &&
440 		    tz->temperature >= trip_temp)
441 			thermal_notify_tz_trip_up(tz->id, trip);
442 		if (tz->last_temperature >= trip_temp &&
443 		    tz->temperature < (trip_temp - hyst))
444 			thermal_notify_tz_trip_down(tz->id, trip);
445 	}
446 
447 	if (type == THERMAL_TRIP_CRITICAL || type == THERMAL_TRIP_HOT)
448 		handle_critical_trips(tz, trip, type);
449 	else
450 		handle_non_critical_trips(tz, trip);
451 	/*
452 	 * Alright, we handled this trip successfully.
453 	 * So, start monitoring again.
454 	 */
455 	monitor_thermal_zone(tz);
456 }
457 
458 static void update_temperature(struct thermal_zone_device *tz)
459 {
460 	int temp, ret;
461 
462 	ret = thermal_zone_get_temp(tz, &temp);
463 	if (ret) {
464 		if (ret != -EAGAIN)
465 			dev_warn(&tz->device,
466 				 "failed to read out thermal zone (%d)\n",
467 				 ret);
468 		return;
469 	}
470 
471 	mutex_lock(&tz->lock);
472 	tz->last_temperature = tz->temperature;
473 	tz->temperature = temp;
474 	mutex_unlock(&tz->lock);
475 
476 	trace_thermal_temperature(tz);
477 
478 	thermal_genl_sampling_temp(tz->id, temp);
479 }
480 
481 static void thermal_zone_device_init(struct thermal_zone_device *tz)
482 {
483 	struct thermal_instance *pos;
484 	tz->temperature = THERMAL_TEMP_INVALID;
485 	list_for_each_entry(pos, &tz->thermal_instances, tz_node)
486 		pos->initialized = false;
487 }
488 
489 static void thermal_zone_device_reset(struct thermal_zone_device *tz)
490 {
491 	tz->passive = 0;
492 	thermal_zone_device_init(tz);
493 }
494 
495 static int thermal_zone_device_set_mode(struct thermal_zone_device *tz,
496 					enum thermal_device_mode mode)
497 {
498 	int ret = 0;
499 
500 	mutex_lock(&tz->lock);
501 
502 	/* do nothing if mode isn't changing */
503 	if (mode == tz->mode) {
504 		mutex_unlock(&tz->lock);
505 
506 		return ret;
507 	}
508 
509 	if (tz->ops->change_mode)
510 		ret = tz->ops->change_mode(tz, mode);
511 
512 	if (!ret)
513 		tz->mode = mode;
514 
515 	mutex_unlock(&tz->lock);
516 
517 	thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
518 
519 	if (mode == THERMAL_DEVICE_ENABLED)
520 		thermal_notify_tz_enable(tz->id);
521 	else
522 		thermal_notify_tz_disable(tz->id);
523 
524 	return ret;
525 }
526 
527 int thermal_zone_device_enable(struct thermal_zone_device *tz)
528 {
529 	return thermal_zone_device_set_mode(tz, THERMAL_DEVICE_ENABLED);
530 }
531 EXPORT_SYMBOL_GPL(thermal_zone_device_enable);
532 
533 int thermal_zone_device_disable(struct thermal_zone_device *tz)
534 {
535 	return thermal_zone_device_set_mode(tz, THERMAL_DEVICE_DISABLED);
536 }
537 EXPORT_SYMBOL_GPL(thermal_zone_device_disable);
538 
539 int thermal_zone_device_is_enabled(struct thermal_zone_device *tz)
540 {
541 	enum thermal_device_mode mode;
542 
543 	mutex_lock(&tz->lock);
544 
545 	mode = tz->mode;
546 
547 	mutex_unlock(&tz->lock);
548 
549 	return mode == THERMAL_DEVICE_ENABLED;
550 }
551 
552 void thermal_zone_device_update(struct thermal_zone_device *tz,
553 				enum thermal_notify_event event)
554 {
555 	int count;
556 
557 	if (should_stop_polling(tz))
558 		return;
559 
560 	if (atomic_read(&in_suspend))
561 		return;
562 
563 	if (WARN_ONCE(!tz->ops->get_temp, "'%s' must not be called without "
564 		      "'get_temp' ops set\n", __func__))
565 		return;
566 
567 	update_temperature(tz);
568 
569 	thermal_zone_set_trips(tz);
570 
571 	tz->notify_event = event;
572 
573 	for (count = 0; count < tz->trips; count++)
574 		handle_thermal_trip(tz, count);
575 }
576 EXPORT_SYMBOL_GPL(thermal_zone_device_update);
577 
578 /**
579  * thermal_notify_framework - Sensor drivers use this API to notify framework
580  * @tz:		thermal zone device
581  * @trip:	indicates which trip point has been crossed
582  *
583  * This function handles the trip events from sensor drivers. It starts
584  * throttling the cooling devices according to the policy configured.
585  * For CRITICAL and HOT trip points, this notifies the respective drivers,
586  * and does actual throttling for other trip points i.e ACTIVE and PASSIVE.
587  * The throttling policy is based on the configured platform data; if no
588  * platform data is provided, this uses the step_wise throttling policy.
589  */
590 void thermal_notify_framework(struct thermal_zone_device *tz, int trip)
591 {
592 	handle_thermal_trip(tz, trip);
593 }
594 EXPORT_SYMBOL_GPL(thermal_notify_framework);
595 
596 static void thermal_zone_device_check(struct work_struct *work)
597 {
598 	struct thermal_zone_device *tz = container_of(work, struct
599 						      thermal_zone_device,
600 						      poll_queue.work);
601 	thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
602 }
603 
604 void thermal_zone_device_rebind_exception(struct thermal_zone_device *tz,
605 					  const char *cdev_type, size_t size)
606 {
607 	struct thermal_cooling_device *cdev = NULL;
608 
609 	mutex_lock(&thermal_list_lock);
610 	list_for_each_entry(cdev, &thermal_cdev_list, node) {
611 		/* skip non matching cdevs */
612 		if (strncmp(cdev_type, cdev->type, size))
613 			continue;
614 
615 		/* re binding the exception matching the type pattern */
616 		thermal_zone_bind_cooling_device(tz, THERMAL_TRIPS_NONE, cdev,
617 						 THERMAL_NO_LIMIT,
618 						 THERMAL_NO_LIMIT,
619 						 THERMAL_WEIGHT_DEFAULT);
620 	}
621 	mutex_unlock(&thermal_list_lock);
622 }
623 
624 int for_each_thermal_governor(int (*cb)(struct thermal_governor *, void *),
625 			      void *data)
626 {
627 	struct thermal_governor *gov;
628 	int ret = 0;
629 
630 	mutex_lock(&thermal_governor_lock);
631 	list_for_each_entry(gov, &thermal_governor_list, governor_list) {
632 		ret = cb(gov, data);
633 		if (ret)
634 			break;
635 	}
636 	mutex_unlock(&thermal_governor_lock);
637 
638 	return ret;
639 }
640 
641 int for_each_thermal_cooling_device(int (*cb)(struct thermal_cooling_device *,
642 					      void *), void *data)
643 {
644 	struct thermal_cooling_device *cdev;
645 	int ret = 0;
646 
647 	mutex_lock(&thermal_list_lock);
648 	list_for_each_entry(cdev, &thermal_cdev_list, node) {
649 		ret = cb(cdev, data);
650 		if (ret)
651 			break;
652 	}
653 	mutex_unlock(&thermal_list_lock);
654 
655 	return ret;
656 }
657 
658 int for_each_thermal_zone(int (*cb)(struct thermal_zone_device *, void *),
659 			  void *data)
660 {
661 	struct thermal_zone_device *tz;
662 	int ret = 0;
663 
664 	mutex_lock(&thermal_list_lock);
665 	list_for_each_entry(tz, &thermal_tz_list, node) {
666 		ret = cb(tz, data);
667 		if (ret)
668 			break;
669 	}
670 	mutex_unlock(&thermal_list_lock);
671 
672 	return ret;
673 }
674 
675 struct thermal_zone_device *thermal_zone_get_by_id(int id)
676 {
677 	struct thermal_zone_device *tz, *match = NULL;
678 
679 	mutex_lock(&thermal_list_lock);
680 	list_for_each_entry(tz, &thermal_tz_list, node) {
681 		if (tz->id == id) {
682 			match = tz;
683 			break;
684 		}
685 	}
686 	mutex_unlock(&thermal_list_lock);
687 
688 	return match;
689 }
690 
691 void thermal_zone_device_unbind_exception(struct thermal_zone_device *tz,
692 					  const char *cdev_type, size_t size)
693 {
694 	struct thermal_cooling_device *cdev = NULL;
695 
696 	mutex_lock(&thermal_list_lock);
697 	list_for_each_entry(cdev, &thermal_cdev_list, node) {
698 		/* skip non matching cdevs */
699 		if (strncmp(cdev_type, cdev->type, size))
700 			continue;
701 		/* unbinding the exception matching the type pattern */
702 		thermal_zone_unbind_cooling_device(tz, THERMAL_TRIPS_NONE,
703 						   cdev);
704 	}
705 	mutex_unlock(&thermal_list_lock);
706 }
707 
708 /*
709  * Device management section: cooling devices, zones devices, and binding
710  *
711  * Set of functions provided by the thermal core for:
712  * - cooling devices lifecycle: registration, unregistration,
713  *				binding, and unbinding.
714  * - thermal zone devices lifecycle: registration, unregistration,
715  *				     binding, and unbinding.
716  */
717 
718 /**
719  * thermal_zone_bind_cooling_device() - bind a cooling device to a thermal zone
720  * @tz:		pointer to struct thermal_zone_device
721  * @trip:	indicates which trip point the cooling devices is
722  *		associated with in this thermal zone.
723  * @cdev:	pointer to struct thermal_cooling_device
724  * @upper:	the Maximum cooling state for this trip point.
725  *		THERMAL_NO_LIMIT means no upper limit,
726  *		and the cooling device can be in max_state.
727  * @lower:	the Minimum cooling state can be used for this trip point.
728  *		THERMAL_NO_LIMIT means no lower limit,
729  *		and the cooling device can be in cooling state 0.
730  * @weight:	The weight of the cooling device to be bound to the
731  *		thermal zone. Use THERMAL_WEIGHT_DEFAULT for the
732  *		default value
733  *
734  * This interface function bind a thermal cooling device to the certain trip
735  * point of a thermal zone device.
736  * This function is usually called in the thermal zone device .bind callback.
737  *
738  * Return: 0 on success, the proper error value otherwise.
739  */
740 int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz,
741 				     int trip,
742 				     struct thermal_cooling_device *cdev,
743 				     unsigned long upper, unsigned long lower,
744 				     unsigned int weight)
745 {
746 	struct thermal_instance *dev;
747 	struct thermal_instance *pos;
748 	struct thermal_zone_device *pos1;
749 	struct thermal_cooling_device *pos2;
750 	unsigned long max_state;
751 	int result, ret;
752 
753 	if (trip >= tz->trips || (trip < 0 && trip != THERMAL_TRIPS_NONE))
754 		return -EINVAL;
755 
756 	list_for_each_entry(pos1, &thermal_tz_list, node) {
757 		if (pos1 == tz)
758 			break;
759 	}
760 	list_for_each_entry(pos2, &thermal_cdev_list, node) {
761 		if (pos2 == cdev)
762 			break;
763 	}
764 
765 	if (tz != pos1 || cdev != pos2)
766 		return -EINVAL;
767 
768 	ret = cdev->ops->get_max_state(cdev, &max_state);
769 	if (ret)
770 		return ret;
771 
772 	/* lower default 0, upper default max_state */
773 	lower = lower == THERMAL_NO_LIMIT ? 0 : lower;
774 	upper = upper == THERMAL_NO_LIMIT ? max_state : upper;
775 
776 	if (lower > upper || upper > max_state)
777 		return -EINVAL;
778 
779 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
780 	if (!dev)
781 		return -ENOMEM;
782 	dev->tz = tz;
783 	dev->cdev = cdev;
784 	dev->trip = trip;
785 	dev->upper = upper;
786 	dev->lower = lower;
787 	dev->target = THERMAL_NO_TARGET;
788 	dev->weight = weight;
789 
790 	result = ida_simple_get(&tz->ida, 0, 0, GFP_KERNEL);
791 	if (result < 0)
792 		goto free_mem;
793 
794 	dev->id = result;
795 	sprintf(dev->name, "cdev%d", dev->id);
796 	result =
797 	    sysfs_create_link(&tz->device.kobj, &cdev->device.kobj, dev->name);
798 	if (result)
799 		goto release_ida;
800 
801 	sprintf(dev->attr_name, "cdev%d_trip_point", dev->id);
802 	sysfs_attr_init(&dev->attr.attr);
803 	dev->attr.attr.name = dev->attr_name;
804 	dev->attr.attr.mode = 0444;
805 	dev->attr.show = trip_point_show;
806 	result = device_create_file(&tz->device, &dev->attr);
807 	if (result)
808 		goto remove_symbol_link;
809 
810 	sprintf(dev->weight_attr_name, "cdev%d_weight", dev->id);
811 	sysfs_attr_init(&dev->weight_attr.attr);
812 	dev->weight_attr.attr.name = dev->weight_attr_name;
813 	dev->weight_attr.attr.mode = S_IWUSR | S_IRUGO;
814 	dev->weight_attr.show = weight_show;
815 	dev->weight_attr.store = weight_store;
816 	result = device_create_file(&tz->device, &dev->weight_attr);
817 	if (result)
818 		goto remove_trip_file;
819 
820 	mutex_lock(&tz->lock);
821 	mutex_lock(&cdev->lock);
822 	list_for_each_entry(pos, &tz->thermal_instances, tz_node)
823 		if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
824 			result = -EEXIST;
825 			break;
826 		}
827 	if (!result) {
828 		list_add_tail(&dev->tz_node, &tz->thermal_instances);
829 		list_add_tail(&dev->cdev_node, &cdev->thermal_instances);
830 		atomic_set(&tz->need_update, 1);
831 	}
832 	mutex_unlock(&cdev->lock);
833 	mutex_unlock(&tz->lock);
834 
835 	if (!result)
836 		return 0;
837 
838 	device_remove_file(&tz->device, &dev->weight_attr);
839 remove_trip_file:
840 	device_remove_file(&tz->device, &dev->attr);
841 remove_symbol_link:
842 	sysfs_remove_link(&tz->device.kobj, dev->name);
843 release_ida:
844 	ida_simple_remove(&tz->ida, dev->id);
845 free_mem:
846 	kfree(dev);
847 	return result;
848 }
849 EXPORT_SYMBOL_GPL(thermal_zone_bind_cooling_device);
850 
851 /**
852  * thermal_zone_unbind_cooling_device() - unbind a cooling device from a
853  *					  thermal zone.
854  * @tz:		pointer to a struct thermal_zone_device.
855  * @trip:	indicates which trip point the cooling devices is
856  *		associated with in this thermal zone.
857  * @cdev:	pointer to a struct thermal_cooling_device.
858  *
859  * This interface function unbind a thermal cooling device from the certain
860  * trip point of a thermal zone device.
861  * This function is usually called in the thermal zone device .unbind callback.
862  *
863  * Return: 0 on success, the proper error value otherwise.
864  */
865 int thermal_zone_unbind_cooling_device(struct thermal_zone_device *tz,
866 				       int trip,
867 				       struct thermal_cooling_device *cdev)
868 {
869 	struct thermal_instance *pos, *next;
870 
871 	mutex_lock(&tz->lock);
872 	mutex_lock(&cdev->lock);
873 	list_for_each_entry_safe(pos, next, &tz->thermal_instances, tz_node) {
874 		if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
875 			list_del(&pos->tz_node);
876 			list_del(&pos->cdev_node);
877 			mutex_unlock(&cdev->lock);
878 			mutex_unlock(&tz->lock);
879 			goto unbind;
880 		}
881 	}
882 	mutex_unlock(&cdev->lock);
883 	mutex_unlock(&tz->lock);
884 
885 	return -ENODEV;
886 
887 unbind:
888 	device_remove_file(&tz->device, &pos->weight_attr);
889 	device_remove_file(&tz->device, &pos->attr);
890 	sysfs_remove_link(&tz->device.kobj, pos->name);
891 	ida_simple_remove(&tz->ida, pos->id);
892 	kfree(pos);
893 	return 0;
894 }
895 EXPORT_SYMBOL_GPL(thermal_zone_unbind_cooling_device);
896 
897 static void thermal_release(struct device *dev)
898 {
899 	struct thermal_zone_device *tz;
900 	struct thermal_cooling_device *cdev;
901 
902 	if (!strncmp(dev_name(dev), "thermal_zone",
903 		     sizeof("thermal_zone") - 1)) {
904 		tz = to_thermal_zone(dev);
905 		thermal_zone_destroy_device_groups(tz);
906 		kfree(tz);
907 	} else if (!strncmp(dev_name(dev), "cooling_device",
908 			    sizeof("cooling_device") - 1)) {
909 		cdev = to_cooling_device(dev);
910 		kfree(cdev);
911 	}
912 }
913 
914 static struct class thermal_class = {
915 	.name = "thermal",
916 	.dev_release = thermal_release,
917 };
918 
919 static inline
920 void print_bind_err_msg(struct thermal_zone_device *tz,
921 			struct thermal_cooling_device *cdev, int ret)
922 {
923 	dev_err(&tz->device, "binding zone %s with cdev %s failed:%d\n",
924 		tz->type, cdev->type, ret);
925 }
926 
927 static void __bind(struct thermal_zone_device *tz, int mask,
928 		   struct thermal_cooling_device *cdev,
929 		   unsigned long *limits,
930 		   unsigned int weight)
931 {
932 	int i, ret;
933 
934 	for (i = 0; i < tz->trips; i++) {
935 		if (mask & (1 << i)) {
936 			unsigned long upper, lower;
937 
938 			upper = THERMAL_NO_LIMIT;
939 			lower = THERMAL_NO_LIMIT;
940 			if (limits) {
941 				lower = limits[i * 2];
942 				upper = limits[i * 2 + 1];
943 			}
944 			ret = thermal_zone_bind_cooling_device(tz, i, cdev,
945 							       upper, lower,
946 							       weight);
947 			if (ret)
948 				print_bind_err_msg(tz, cdev, ret);
949 		}
950 	}
951 }
952 
953 static void bind_cdev(struct thermal_cooling_device *cdev)
954 {
955 	int i, ret;
956 	const struct thermal_zone_params *tzp;
957 	struct thermal_zone_device *pos = NULL;
958 
959 	mutex_lock(&thermal_list_lock);
960 
961 	list_for_each_entry(pos, &thermal_tz_list, node) {
962 		if (!pos->tzp && !pos->ops->bind)
963 			continue;
964 
965 		if (pos->ops->bind) {
966 			ret = pos->ops->bind(pos, cdev);
967 			if (ret)
968 				print_bind_err_msg(pos, cdev, ret);
969 			continue;
970 		}
971 
972 		tzp = pos->tzp;
973 		if (!tzp || !tzp->tbp)
974 			continue;
975 
976 		for (i = 0; i < tzp->num_tbps; i++) {
977 			if (tzp->tbp[i].cdev || !tzp->tbp[i].match)
978 				continue;
979 			if (tzp->tbp[i].match(pos, cdev))
980 				continue;
981 			tzp->tbp[i].cdev = cdev;
982 			__bind(pos, tzp->tbp[i].trip_mask, cdev,
983 			       tzp->tbp[i].binding_limits,
984 			       tzp->tbp[i].weight);
985 		}
986 	}
987 
988 	mutex_unlock(&thermal_list_lock);
989 }
990 
991 /**
992  * __thermal_cooling_device_register() - register a new thermal cooling device
993  * @np:		a pointer to a device tree node.
994  * @type:	the thermal cooling device type.
995  * @devdata:	device private data.
996  * @ops:		standard thermal cooling devices callbacks.
997  *
998  * This interface function adds a new thermal cooling device (fan/processor/...)
999  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
1000  * to all the thermal zone devices registered at the same time.
1001  * It also gives the opportunity to link the cooling device to a device tree
1002  * node, so that it can be bound to a thermal zone created out of device tree.
1003  *
1004  * Return: a pointer to the created struct thermal_cooling_device or an
1005  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
1006  */
1007 static struct thermal_cooling_device *
1008 __thermal_cooling_device_register(struct device_node *np,
1009 				  const char *type, void *devdata,
1010 				  const struct thermal_cooling_device_ops *ops)
1011 {
1012 	struct thermal_cooling_device *cdev;
1013 	struct thermal_zone_device *pos = NULL;
1014 	int result;
1015 
1016 	if (type && strlen(type) >= THERMAL_NAME_LENGTH)
1017 		return ERR_PTR(-EINVAL);
1018 
1019 	if (!ops || !ops->get_max_state || !ops->get_cur_state ||
1020 	    !ops->set_cur_state)
1021 		return ERR_PTR(-EINVAL);
1022 
1023 	cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
1024 	if (!cdev)
1025 		return ERR_PTR(-ENOMEM);
1026 
1027 	result = ida_simple_get(&thermal_cdev_ida, 0, 0, GFP_KERNEL);
1028 	if (result < 0) {
1029 		kfree(cdev);
1030 		return ERR_PTR(result);
1031 	}
1032 
1033 	cdev->id = result;
1034 	strlcpy(cdev->type, type ? : "", sizeof(cdev->type));
1035 	mutex_init(&cdev->lock);
1036 	INIT_LIST_HEAD(&cdev->thermal_instances);
1037 	cdev->np = np;
1038 	cdev->ops = ops;
1039 	cdev->updated = false;
1040 	cdev->device.class = &thermal_class;
1041 	cdev->devdata = devdata;
1042 	thermal_cooling_device_setup_sysfs(cdev);
1043 	dev_set_name(&cdev->device, "cooling_device%d", cdev->id);
1044 	result = device_register(&cdev->device);
1045 	if (result) {
1046 		ida_simple_remove(&thermal_cdev_ida, cdev->id);
1047 		put_device(&cdev->device);
1048 		return ERR_PTR(result);
1049 	}
1050 
1051 	/* Add 'this' new cdev to the global cdev list */
1052 	mutex_lock(&thermal_list_lock);
1053 	list_add(&cdev->node, &thermal_cdev_list);
1054 	mutex_unlock(&thermal_list_lock);
1055 
1056 	/* Update binding information for 'this' new cdev */
1057 	bind_cdev(cdev);
1058 
1059 	mutex_lock(&thermal_list_lock);
1060 	list_for_each_entry(pos, &thermal_tz_list, node)
1061 		if (atomic_cmpxchg(&pos->need_update, 1, 0))
1062 			thermal_zone_device_update(pos,
1063 						   THERMAL_EVENT_UNSPECIFIED);
1064 	mutex_unlock(&thermal_list_lock);
1065 
1066 	return cdev;
1067 }
1068 
1069 /**
1070  * thermal_cooling_device_register() - register a new thermal cooling device
1071  * @type:	the thermal cooling device type.
1072  * @devdata:	device private data.
1073  * @ops:		standard thermal cooling devices callbacks.
1074  *
1075  * This interface function adds a new thermal cooling device (fan/processor/...)
1076  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
1077  * to all the thermal zone devices registered at the same time.
1078  *
1079  * Return: a pointer to the created struct thermal_cooling_device or an
1080  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
1081  */
1082 struct thermal_cooling_device *
1083 thermal_cooling_device_register(const char *type, void *devdata,
1084 				const struct thermal_cooling_device_ops *ops)
1085 {
1086 	return __thermal_cooling_device_register(NULL, type, devdata, ops);
1087 }
1088 EXPORT_SYMBOL_GPL(thermal_cooling_device_register);
1089 
1090 /**
1091  * thermal_of_cooling_device_register() - register an OF thermal cooling device
1092  * @np:		a pointer to a device tree node.
1093  * @type:	the thermal cooling device type.
1094  * @devdata:	device private data.
1095  * @ops:		standard thermal cooling devices callbacks.
1096  *
1097  * This function will register a cooling device with device tree node reference.
1098  * This interface function adds a new thermal cooling device (fan/processor/...)
1099  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
1100  * to all the thermal zone devices registered at the same time.
1101  *
1102  * Return: a pointer to the created struct thermal_cooling_device or an
1103  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
1104  */
1105 struct thermal_cooling_device *
1106 thermal_of_cooling_device_register(struct device_node *np,
1107 				   const char *type, void *devdata,
1108 				   const struct thermal_cooling_device_ops *ops)
1109 {
1110 	return __thermal_cooling_device_register(np, type, devdata, ops);
1111 }
1112 EXPORT_SYMBOL_GPL(thermal_of_cooling_device_register);
1113 
1114 static void thermal_cooling_device_release(struct device *dev, void *res)
1115 {
1116 	thermal_cooling_device_unregister(
1117 				*(struct thermal_cooling_device **)res);
1118 }
1119 
1120 /**
1121  * devm_thermal_of_cooling_device_register() - register an OF thermal cooling
1122  *					       device
1123  * @dev:	a valid struct device pointer of a sensor device.
1124  * @np:		a pointer to a device tree node.
1125  * @type:	the thermal cooling device type.
1126  * @devdata:	device private data.
1127  * @ops:	standard thermal cooling devices callbacks.
1128  *
1129  * This function will register a cooling device with device tree node reference.
1130  * This interface function adds a new thermal cooling device (fan/processor/...)
1131  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
1132  * to all the thermal zone devices registered at the same time.
1133  *
1134  * Return: a pointer to the created struct thermal_cooling_device or an
1135  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
1136  */
1137 struct thermal_cooling_device *
1138 devm_thermal_of_cooling_device_register(struct device *dev,
1139 				struct device_node *np,
1140 				char *type, void *devdata,
1141 				const struct thermal_cooling_device_ops *ops)
1142 {
1143 	struct thermal_cooling_device **ptr, *tcd;
1144 
1145 	ptr = devres_alloc(thermal_cooling_device_release, sizeof(*ptr),
1146 			   GFP_KERNEL);
1147 	if (!ptr)
1148 		return ERR_PTR(-ENOMEM);
1149 
1150 	tcd = __thermal_cooling_device_register(np, type, devdata, ops);
1151 	if (IS_ERR(tcd)) {
1152 		devres_free(ptr);
1153 		return tcd;
1154 	}
1155 
1156 	*ptr = tcd;
1157 	devres_add(dev, ptr);
1158 
1159 	return tcd;
1160 }
1161 EXPORT_SYMBOL_GPL(devm_thermal_of_cooling_device_register);
1162 
1163 static void __unbind(struct thermal_zone_device *tz, int mask,
1164 		     struct thermal_cooling_device *cdev)
1165 {
1166 	int i;
1167 
1168 	for (i = 0; i < tz->trips; i++)
1169 		if (mask & (1 << i))
1170 			thermal_zone_unbind_cooling_device(tz, i, cdev);
1171 }
1172 
1173 /**
1174  * thermal_cooling_device_unregister - removes a thermal cooling device
1175  * @cdev:	the thermal cooling device to remove.
1176  *
1177  * thermal_cooling_device_unregister() must be called when a registered
1178  * thermal cooling device is no longer needed.
1179  */
1180 void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev)
1181 {
1182 	int i;
1183 	const struct thermal_zone_params *tzp;
1184 	struct thermal_zone_device *tz;
1185 	struct thermal_cooling_device *pos = NULL;
1186 
1187 	if (!cdev)
1188 		return;
1189 
1190 	mutex_lock(&thermal_list_lock);
1191 	list_for_each_entry(pos, &thermal_cdev_list, node)
1192 		if (pos == cdev)
1193 			break;
1194 	if (pos != cdev) {
1195 		/* thermal cooling device not found */
1196 		mutex_unlock(&thermal_list_lock);
1197 		return;
1198 	}
1199 	list_del(&cdev->node);
1200 
1201 	/* Unbind all thermal zones associated with 'this' cdev */
1202 	list_for_each_entry(tz, &thermal_tz_list, node) {
1203 		if (tz->ops->unbind) {
1204 			tz->ops->unbind(tz, cdev);
1205 			continue;
1206 		}
1207 
1208 		if (!tz->tzp || !tz->tzp->tbp)
1209 			continue;
1210 
1211 		tzp = tz->tzp;
1212 		for (i = 0; i < tzp->num_tbps; i++) {
1213 			if (tzp->tbp[i].cdev == cdev) {
1214 				__unbind(tz, tzp->tbp[i].trip_mask, cdev);
1215 				tzp->tbp[i].cdev = NULL;
1216 			}
1217 		}
1218 	}
1219 
1220 	mutex_unlock(&thermal_list_lock);
1221 
1222 	ida_simple_remove(&thermal_cdev_ida, cdev->id);
1223 	device_del(&cdev->device);
1224 	thermal_cooling_device_destroy_sysfs(cdev);
1225 	put_device(&cdev->device);
1226 }
1227 EXPORT_SYMBOL_GPL(thermal_cooling_device_unregister);
1228 
1229 static void bind_tz(struct thermal_zone_device *tz)
1230 {
1231 	int i, ret;
1232 	struct thermal_cooling_device *pos = NULL;
1233 	const struct thermal_zone_params *tzp = tz->tzp;
1234 
1235 	if (!tzp && !tz->ops->bind)
1236 		return;
1237 
1238 	mutex_lock(&thermal_list_lock);
1239 
1240 	/* If there is ops->bind, try to use ops->bind */
1241 	if (tz->ops->bind) {
1242 		list_for_each_entry(pos, &thermal_cdev_list, node) {
1243 			ret = tz->ops->bind(tz, pos);
1244 			if (ret)
1245 				print_bind_err_msg(tz, pos, ret);
1246 		}
1247 		goto exit;
1248 	}
1249 
1250 	if (!tzp || !tzp->tbp)
1251 		goto exit;
1252 
1253 	list_for_each_entry(pos, &thermal_cdev_list, node) {
1254 		for (i = 0; i < tzp->num_tbps; i++) {
1255 			if (tzp->tbp[i].cdev || !tzp->tbp[i].match)
1256 				continue;
1257 			if (tzp->tbp[i].match(tz, pos))
1258 				continue;
1259 			tzp->tbp[i].cdev = pos;
1260 			__bind(tz, tzp->tbp[i].trip_mask, pos,
1261 			       tzp->tbp[i].binding_limits,
1262 			       tzp->tbp[i].weight);
1263 		}
1264 	}
1265 exit:
1266 	mutex_unlock(&thermal_list_lock);
1267 }
1268 
1269 /**
1270  * thermal_zone_device_register() - register a new thermal zone device
1271  * @type:	the thermal zone device type
1272  * @trips:	the number of trip points the thermal zone support
1273  * @mask:	a bit string indicating the writeablility of trip points
1274  * @devdata:	private device data
1275  * @ops:	standard thermal zone device callbacks
1276  * @tzp:	thermal zone platform parameters
1277  * @passive_delay: number of milliseconds to wait between polls when
1278  *		   performing passive cooling
1279  * @polling_delay: number of milliseconds to wait between polls when checking
1280  *		   whether trip points have been crossed (0 for interrupt
1281  *		   driven systems)
1282  *
1283  * This interface function adds a new thermal zone device (sensor) to
1284  * /sys/class/thermal folder as thermal_zone[0-*]. It tries to bind all the
1285  * thermal cooling devices registered at the same time.
1286  * thermal_zone_device_unregister() must be called when the device is no
1287  * longer needed. The passive cooling depends on the .get_trend() return value.
1288  *
1289  * Return: a pointer to the created struct thermal_zone_device or an
1290  * in case of error, an ERR_PTR. Caller must check return value with
1291  * IS_ERR*() helpers.
1292  */
1293 struct thermal_zone_device *
1294 thermal_zone_device_register(const char *type, int trips, int mask,
1295 			     void *devdata, struct thermal_zone_device_ops *ops,
1296 			     struct thermal_zone_params *tzp, int passive_delay,
1297 			     int polling_delay)
1298 {
1299 	struct thermal_zone_device *tz;
1300 	enum thermal_trip_type trip_type;
1301 	int trip_temp;
1302 	int id;
1303 	int result;
1304 	int count;
1305 	struct thermal_governor *governor;
1306 
1307 	if (!type || strlen(type) == 0) {
1308 		pr_err("Error: No thermal zone type defined\n");
1309 		return ERR_PTR(-EINVAL);
1310 	}
1311 
1312 	if (type && strlen(type) >= THERMAL_NAME_LENGTH) {
1313 		pr_err("Error: Thermal zone name (%s) too long, should be under %d chars\n",
1314 		       type, THERMAL_NAME_LENGTH);
1315 		return ERR_PTR(-EINVAL);
1316 	}
1317 
1318 	if (trips > THERMAL_MAX_TRIPS || trips < 0 || mask >> trips) {
1319 		pr_err("Error: Incorrect number of thermal trips\n");
1320 		return ERR_PTR(-EINVAL);
1321 	}
1322 
1323 	if (!ops) {
1324 		pr_err("Error: Thermal zone device ops not defined\n");
1325 		return ERR_PTR(-EINVAL);
1326 	}
1327 
1328 	if (trips > 0 && (!ops->get_trip_type || !ops->get_trip_temp))
1329 		return ERR_PTR(-EINVAL);
1330 
1331 	tz = kzalloc(sizeof(*tz), GFP_KERNEL);
1332 	if (!tz)
1333 		return ERR_PTR(-ENOMEM);
1334 
1335 	INIT_LIST_HEAD(&tz->thermal_instances);
1336 	ida_init(&tz->ida);
1337 	mutex_init(&tz->lock);
1338 	id = ida_simple_get(&thermal_tz_ida, 0, 0, GFP_KERNEL);
1339 	if (id < 0) {
1340 		result = id;
1341 		goto free_tz;
1342 	}
1343 
1344 	tz->id = id;
1345 	strlcpy(tz->type, type, sizeof(tz->type));
1346 
1347 	if (!ops->critical)
1348 		ops->critical = thermal_zone_device_critical;
1349 
1350 	tz->ops = ops;
1351 	tz->tzp = tzp;
1352 	tz->device.class = &thermal_class;
1353 	tz->devdata = devdata;
1354 	tz->trips = trips;
1355 	tz->passive_delay = passive_delay;
1356 	tz->polling_delay = polling_delay;
1357 
1358 	/* sys I/F */
1359 	/* Add nodes that are always present via .groups */
1360 	result = thermal_zone_create_device_groups(tz, mask);
1361 	if (result)
1362 		goto remove_id;
1363 
1364 	/* A new thermal zone needs to be updated anyway. */
1365 	atomic_set(&tz->need_update, 1);
1366 
1367 	dev_set_name(&tz->device, "thermal_zone%d", tz->id);
1368 	result = device_register(&tz->device);
1369 	if (result)
1370 		goto release_device;
1371 
1372 	for (count = 0; count < trips; count++) {
1373 		if (tz->ops->get_trip_type(tz, count, &trip_type) ||
1374 		    tz->ops->get_trip_temp(tz, count, &trip_temp) ||
1375 		    !trip_temp)
1376 			set_bit(count, &tz->trips_disabled);
1377 	}
1378 
1379 	/* Update 'this' zone's governor information */
1380 	mutex_lock(&thermal_governor_lock);
1381 
1382 	if (tz->tzp)
1383 		governor = __find_governor(tz->tzp->governor_name);
1384 	else
1385 		governor = def_governor;
1386 
1387 	result = thermal_set_governor(tz, governor);
1388 	if (result) {
1389 		mutex_unlock(&thermal_governor_lock);
1390 		goto unregister;
1391 	}
1392 
1393 	mutex_unlock(&thermal_governor_lock);
1394 
1395 	if (!tz->tzp || !tz->tzp->no_hwmon) {
1396 		result = thermal_add_hwmon_sysfs(tz);
1397 		if (result)
1398 			goto unregister;
1399 	}
1400 
1401 	mutex_lock(&thermal_list_lock);
1402 	list_add_tail(&tz->node, &thermal_tz_list);
1403 	mutex_unlock(&thermal_list_lock);
1404 
1405 	/* Bind cooling devices for this zone */
1406 	bind_tz(tz);
1407 
1408 	INIT_DELAYED_WORK(&tz->poll_queue, thermal_zone_device_check);
1409 
1410 	thermal_zone_device_reset(tz);
1411 	/* Update the new thermal zone and mark it as already updated. */
1412 	if (atomic_cmpxchg(&tz->need_update, 1, 0))
1413 		thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
1414 
1415 	thermal_notify_tz_create(tz->id, tz->type);
1416 
1417 	return tz;
1418 
1419 unregister:
1420 	device_del(&tz->device);
1421 release_device:
1422 	put_device(&tz->device);
1423 	tz = NULL;
1424 remove_id:
1425 	ida_simple_remove(&thermal_tz_ida, id);
1426 free_tz:
1427 	kfree(tz);
1428 	return ERR_PTR(result);
1429 }
1430 EXPORT_SYMBOL_GPL(thermal_zone_device_register);
1431 
1432 /**
1433  * thermal_device_unregister - removes the registered thermal zone device
1434  * @tz: the thermal zone device to remove
1435  */
1436 void thermal_zone_device_unregister(struct thermal_zone_device *tz)
1437 {
1438 	int i, tz_id;
1439 	const struct thermal_zone_params *tzp;
1440 	struct thermal_cooling_device *cdev;
1441 	struct thermal_zone_device *pos = NULL;
1442 
1443 	if (!tz)
1444 		return;
1445 
1446 	tzp = tz->tzp;
1447 	tz_id = tz->id;
1448 
1449 	mutex_lock(&thermal_list_lock);
1450 	list_for_each_entry(pos, &thermal_tz_list, node)
1451 		if (pos == tz)
1452 			break;
1453 	if (pos != tz) {
1454 		/* thermal zone device not found */
1455 		mutex_unlock(&thermal_list_lock);
1456 		return;
1457 	}
1458 	list_del(&tz->node);
1459 
1460 	/* Unbind all cdevs associated with 'this' thermal zone */
1461 	list_for_each_entry(cdev, &thermal_cdev_list, node) {
1462 		if (tz->ops->unbind) {
1463 			tz->ops->unbind(tz, cdev);
1464 			continue;
1465 		}
1466 
1467 		if (!tzp || !tzp->tbp)
1468 			break;
1469 
1470 		for (i = 0; i < tzp->num_tbps; i++) {
1471 			if (tzp->tbp[i].cdev == cdev) {
1472 				__unbind(tz, tzp->tbp[i].trip_mask, cdev);
1473 				tzp->tbp[i].cdev = NULL;
1474 			}
1475 		}
1476 	}
1477 
1478 	mutex_unlock(&thermal_list_lock);
1479 
1480 	cancel_delayed_work_sync(&tz->poll_queue);
1481 
1482 	thermal_set_governor(tz, NULL);
1483 
1484 	thermal_remove_hwmon_sysfs(tz);
1485 	ida_simple_remove(&thermal_tz_ida, tz->id);
1486 	ida_destroy(&tz->ida);
1487 	mutex_destroy(&tz->lock);
1488 	device_unregister(&tz->device);
1489 
1490 	thermal_notify_tz_delete(tz_id);
1491 }
1492 EXPORT_SYMBOL_GPL(thermal_zone_device_unregister);
1493 
1494 /**
1495  * thermal_zone_get_zone_by_name() - search for a zone and returns its ref
1496  * @name: thermal zone name to fetch the temperature
1497  *
1498  * When only one zone is found with the passed name, returns a reference to it.
1499  *
1500  * Return: On success returns a reference to an unique thermal zone with
1501  * matching name equals to @name, an ERR_PTR otherwise (-EINVAL for invalid
1502  * paramenters, -ENODEV for not found and -EEXIST for multiple matches).
1503  */
1504 struct thermal_zone_device *thermal_zone_get_zone_by_name(const char *name)
1505 {
1506 	struct thermal_zone_device *pos = NULL, *ref = ERR_PTR(-EINVAL);
1507 	unsigned int found = 0;
1508 
1509 	if (!name)
1510 		goto exit;
1511 
1512 	mutex_lock(&thermal_list_lock);
1513 	list_for_each_entry(pos, &thermal_tz_list, node)
1514 		if (!strncasecmp(name, pos->type, THERMAL_NAME_LENGTH)) {
1515 			found++;
1516 			ref = pos;
1517 		}
1518 	mutex_unlock(&thermal_list_lock);
1519 
1520 	/* nothing has been found, thus an error code for it */
1521 	if (found == 0)
1522 		ref = ERR_PTR(-ENODEV);
1523 	else if (found > 1)
1524 	/* Success only when an unique zone is found */
1525 		ref = ERR_PTR(-EEXIST);
1526 
1527 exit:
1528 	return ref;
1529 }
1530 EXPORT_SYMBOL_GPL(thermal_zone_get_zone_by_name);
1531 
1532 static int thermal_pm_notify(struct notifier_block *nb,
1533 			     unsigned long mode, void *_unused)
1534 {
1535 	struct thermal_zone_device *tz;
1536 
1537 	switch (mode) {
1538 	case PM_HIBERNATION_PREPARE:
1539 	case PM_RESTORE_PREPARE:
1540 	case PM_SUSPEND_PREPARE:
1541 		atomic_set(&in_suspend, 1);
1542 		break;
1543 	case PM_POST_HIBERNATION:
1544 	case PM_POST_RESTORE:
1545 	case PM_POST_SUSPEND:
1546 		atomic_set(&in_suspend, 0);
1547 		list_for_each_entry(tz, &thermal_tz_list, node) {
1548 			if (!thermal_zone_device_is_enabled(tz))
1549 				continue;
1550 
1551 			thermal_zone_device_init(tz);
1552 			thermal_zone_device_update(tz,
1553 						   THERMAL_EVENT_UNSPECIFIED);
1554 		}
1555 		break;
1556 	default:
1557 		break;
1558 	}
1559 	return 0;
1560 }
1561 
1562 static struct notifier_block thermal_pm_nb = {
1563 	.notifier_call = thermal_pm_notify,
1564 };
1565 
1566 static int __init thermal_init(void)
1567 {
1568 	int result;
1569 
1570 	result = thermal_netlink_init();
1571 	if (result)
1572 		goto error;
1573 
1574 	result = thermal_register_governors();
1575 	if (result)
1576 		goto error;
1577 
1578 	result = class_register(&thermal_class);
1579 	if (result)
1580 		goto unregister_governors;
1581 
1582 	result = of_parse_thermal_zones();
1583 	if (result)
1584 		goto unregister_class;
1585 
1586 	result = register_pm_notifier(&thermal_pm_nb);
1587 	if (result)
1588 		pr_warn("Thermal: Can not register suspend notifier, return %d\n",
1589 			result);
1590 
1591 	return 0;
1592 
1593 unregister_class:
1594 	class_unregister(&thermal_class);
1595 unregister_governors:
1596 	thermal_unregister_governors();
1597 error:
1598 	ida_destroy(&thermal_tz_ida);
1599 	ida_destroy(&thermal_cdev_ida);
1600 	mutex_destroy(&thermal_list_lock);
1601 	mutex_destroy(&thermal_governor_lock);
1602 	mutex_destroy(&poweroff_lock);
1603 	return result;
1604 }
1605 postcore_initcall(thermal_init);
1606