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 	if (!device_is_registered(&tz->device))
205 		goto exit;
206 
207 	gov = __find_governor(strim(policy));
208 	if (!gov)
209 		goto exit;
210 
211 	ret = thermal_set_governor(tz, gov);
212 
213 exit:
214 	mutex_unlock(&tz->lock);
215 	mutex_unlock(&thermal_governor_lock);
216 
217 	thermal_notify_tz_gov_change(tz->id, policy);
218 
219 	return ret;
220 }
221 
222 int thermal_build_list_of_policies(char *buf)
223 {
224 	struct thermal_governor *pos;
225 	ssize_t count = 0;
226 
227 	mutex_lock(&thermal_governor_lock);
228 
229 	list_for_each_entry(pos, &thermal_governor_list, governor_list) {
230 		count += sysfs_emit_at(buf, count, "%s ", pos->name);
231 	}
232 	count += sysfs_emit_at(buf, count, "\n");
233 
234 	mutex_unlock(&thermal_governor_lock);
235 
236 	return count;
237 }
238 
239 static void __init thermal_unregister_governors(void)
240 {
241 	struct thermal_governor **governor;
242 
243 	for_each_governor_table(governor)
244 		thermal_unregister_governor(*governor);
245 }
246 
247 static int __init thermal_register_governors(void)
248 {
249 	int ret = 0;
250 	struct thermal_governor **governor;
251 
252 	for_each_governor_table(governor) {
253 		ret = thermal_register_governor(*governor);
254 		if (ret) {
255 			pr_err("Failed to register governor: '%s'",
256 			       (*governor)->name);
257 			break;
258 		}
259 
260 		pr_info("Registered thermal governor '%s'",
261 			(*governor)->name);
262 	}
263 
264 	if (ret) {
265 		struct thermal_governor **gov;
266 
267 		for_each_governor_table(gov) {
268 			if (gov == governor)
269 				break;
270 			thermal_unregister_governor(*gov);
271 		}
272 	}
273 
274 	return ret;
275 }
276 
277 /*
278  * Zone update section: main control loop applied to each zone while monitoring
279  *
280  * in polling mode. The monitoring is done using a workqueue.
281  * Same update may be done on a zone by calling thermal_zone_device_update().
282  *
283  * An update means:
284  * - Non-critical trips will invoke the governor responsible for that zone;
285  * - Hot trips will produce a notification to userspace;
286  * - Critical trip point will cause a system shutdown.
287  */
288 static void thermal_zone_device_set_polling(struct thermal_zone_device *tz,
289 					    unsigned long delay)
290 {
291 	if (delay)
292 		mod_delayed_work(system_freezable_power_efficient_wq,
293 				 &tz->poll_queue, delay);
294 	else
295 		cancel_delayed_work(&tz->poll_queue);
296 }
297 
298 static void monitor_thermal_zone(struct thermal_zone_device *tz)
299 {
300 	if (tz->mode != THERMAL_DEVICE_ENABLED)
301 		thermal_zone_device_set_polling(tz, 0);
302 	else if (tz->passive)
303 		thermal_zone_device_set_polling(tz, tz->passive_delay_jiffies);
304 	else if (tz->polling_delay_jiffies)
305 		thermal_zone_device_set_polling(tz, tz->polling_delay_jiffies);
306 }
307 
308 static void handle_non_critical_trips(struct thermal_zone_device *tz, int trip)
309 {
310 	tz->governor ? tz->governor->throttle(tz, trip) :
311 		       def_governor->throttle(tz, trip);
312 }
313 
314 void thermal_zone_device_critical(struct thermal_zone_device *tz)
315 {
316 	/*
317 	 * poweroff_delay_ms must be a carefully profiled positive value.
318 	 * Its a must for forced_emergency_poweroff_work to be scheduled.
319 	 */
320 	int poweroff_delay_ms = CONFIG_THERMAL_EMERGENCY_POWEROFF_DELAY_MS;
321 
322 	dev_emerg(&tz->device, "%s: critical temperature reached, "
323 		  "shutting down\n", tz->type);
324 
325 	hw_protection_shutdown("Temperature too high", poweroff_delay_ms);
326 }
327 EXPORT_SYMBOL(thermal_zone_device_critical);
328 
329 static void handle_critical_trips(struct thermal_zone_device *tz,
330 				  int trip, int trip_temp, enum thermal_trip_type trip_type)
331 {
332 	/* If we have not crossed the trip_temp, we do not care. */
333 	if (trip_temp <= 0 || tz->temperature < trip_temp)
334 		return;
335 
336 	trace_thermal_zone_trip(tz, trip, trip_type);
337 
338 	if (trip_type == THERMAL_TRIP_HOT && tz->ops->hot)
339 		tz->ops->hot(tz);
340 	else if (trip_type == THERMAL_TRIP_CRITICAL)
341 		tz->ops->critical(tz);
342 }
343 
344 static void handle_thermal_trip(struct thermal_zone_device *tz, int trip_id)
345 {
346 	struct thermal_trip trip;
347 
348 	/* Ignore disabled trip points */
349 	if (test_bit(trip_id, &tz->trips_disabled))
350 		return;
351 
352 	__thermal_zone_get_trip(tz, trip_id, &trip);
353 
354 	if (trip.temperature == THERMAL_TEMP_INVALID)
355 		return;
356 
357 	if (tz->last_temperature != THERMAL_TEMP_INVALID) {
358 		if (tz->last_temperature < trip.temperature &&
359 		    tz->temperature >= trip.temperature)
360 			thermal_notify_tz_trip_up(tz->id, trip_id,
361 						  tz->temperature);
362 		if (tz->last_temperature >= trip.temperature &&
363 		    tz->temperature < (trip.temperature - trip.hysteresis))
364 			thermal_notify_tz_trip_down(tz->id, trip_id,
365 						    tz->temperature);
366 	}
367 
368 	if (trip.type == THERMAL_TRIP_CRITICAL || trip.type == THERMAL_TRIP_HOT)
369 		handle_critical_trips(tz, trip_id, trip.temperature, trip.type);
370 	else
371 		handle_non_critical_trips(tz, trip_id);
372 }
373 
374 static void update_temperature(struct thermal_zone_device *tz)
375 {
376 	int temp, ret;
377 
378 	ret = __thermal_zone_get_temp(tz, &temp);
379 	if (ret) {
380 		if (ret != -EAGAIN)
381 			dev_warn(&tz->device,
382 				 "failed to read out thermal zone (%d)\n",
383 				 ret);
384 		return;
385 	}
386 
387 	tz->last_temperature = tz->temperature;
388 	tz->temperature = temp;
389 
390 	trace_thermal_temperature(tz);
391 
392 	thermal_genl_sampling_temp(tz->id, temp);
393 }
394 
395 static void thermal_zone_device_init(struct thermal_zone_device *tz)
396 {
397 	struct thermal_instance *pos;
398 	tz->temperature = THERMAL_TEMP_INVALID;
399 	tz->prev_low_trip = -INT_MAX;
400 	tz->prev_high_trip = INT_MAX;
401 	list_for_each_entry(pos, &tz->thermal_instances, tz_node)
402 		pos->initialized = false;
403 }
404 
405 void __thermal_zone_device_update(struct thermal_zone_device *tz,
406 				  enum thermal_notify_event event)
407 {
408 	int count;
409 
410 	if (tz->suspended)
411 		return;
412 
413 	if (WARN_ONCE(!tz->ops->get_temp,
414 		      "'%s' must not be called without 'get_temp' ops set\n",
415 		      __func__))
416 		return;
417 
418 	if (!thermal_zone_device_is_enabled(tz))
419 		return;
420 
421 	update_temperature(tz);
422 
423 	__thermal_zone_set_trips(tz);
424 
425 	tz->notify_event = event;
426 
427 	for (count = 0; count < tz->num_trips; count++)
428 		handle_thermal_trip(tz, count);
429 
430 	monitor_thermal_zone(tz);
431 }
432 
433 static int thermal_zone_device_set_mode(struct thermal_zone_device *tz,
434 					enum thermal_device_mode mode)
435 {
436 	int ret = 0;
437 
438 	mutex_lock(&tz->lock);
439 
440 	/* do nothing if mode isn't changing */
441 	if (mode == tz->mode) {
442 		mutex_unlock(&tz->lock);
443 
444 		return ret;
445 	}
446 
447 	if (!device_is_registered(&tz->device)) {
448 		mutex_unlock(&tz->lock);
449 
450 		return -ENODEV;
451 	}
452 
453 	if (tz->ops->change_mode)
454 		ret = tz->ops->change_mode(tz, mode);
455 
456 	if (!ret)
457 		tz->mode = mode;
458 
459 	__thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
460 
461 	mutex_unlock(&tz->lock);
462 
463 	if (mode == THERMAL_DEVICE_ENABLED)
464 		thermal_notify_tz_enable(tz->id);
465 	else
466 		thermal_notify_tz_disable(tz->id);
467 
468 	return ret;
469 }
470 
471 int thermal_zone_device_enable(struct thermal_zone_device *tz)
472 {
473 	return thermal_zone_device_set_mode(tz, THERMAL_DEVICE_ENABLED);
474 }
475 EXPORT_SYMBOL_GPL(thermal_zone_device_enable);
476 
477 int thermal_zone_device_disable(struct thermal_zone_device *tz)
478 {
479 	return thermal_zone_device_set_mode(tz, THERMAL_DEVICE_DISABLED);
480 }
481 EXPORT_SYMBOL_GPL(thermal_zone_device_disable);
482 
483 int thermal_zone_device_is_enabled(struct thermal_zone_device *tz)
484 {
485 	lockdep_assert_held(&tz->lock);
486 
487 	return tz->mode == THERMAL_DEVICE_ENABLED;
488 }
489 
490 void thermal_zone_device_update(struct thermal_zone_device *tz,
491 				enum thermal_notify_event event)
492 {
493 	mutex_lock(&tz->lock);
494 	if (device_is_registered(&tz->device))
495 		__thermal_zone_device_update(tz, event);
496 	mutex_unlock(&tz->lock);
497 }
498 EXPORT_SYMBOL_GPL(thermal_zone_device_update);
499 
500 /**
501  * thermal_zone_device_exec - Run a callback under the zone lock.
502  * @tz: Thermal zone.
503  * @cb: Callback to run.
504  * @data: Data to pass to the callback.
505  */
506 void thermal_zone_device_exec(struct thermal_zone_device *tz,
507 			      void (*cb)(struct thermal_zone_device *,
508 					 unsigned long),
509 			      unsigned long data)
510 {
511 	mutex_lock(&tz->lock);
512 
513 	cb(tz, data);
514 
515 	mutex_unlock(&tz->lock);
516 }
517 EXPORT_SYMBOL_GPL(thermal_zone_device_exec);
518 
519 static void thermal_zone_device_check(struct work_struct *work)
520 {
521 	struct thermal_zone_device *tz = container_of(work, struct
522 						      thermal_zone_device,
523 						      poll_queue.work);
524 	thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
525 }
526 
527 int for_each_thermal_governor(int (*cb)(struct thermal_governor *, void *),
528 			      void *data)
529 {
530 	struct thermal_governor *gov;
531 	int ret = 0;
532 
533 	mutex_lock(&thermal_governor_lock);
534 	list_for_each_entry(gov, &thermal_governor_list, governor_list) {
535 		ret = cb(gov, data);
536 		if (ret)
537 			break;
538 	}
539 	mutex_unlock(&thermal_governor_lock);
540 
541 	return ret;
542 }
543 
544 int for_each_thermal_cooling_device(int (*cb)(struct thermal_cooling_device *,
545 					      void *), void *data)
546 {
547 	struct thermal_cooling_device *cdev;
548 	int ret = 0;
549 
550 	mutex_lock(&thermal_list_lock);
551 	list_for_each_entry(cdev, &thermal_cdev_list, node) {
552 		ret = cb(cdev, data);
553 		if (ret)
554 			break;
555 	}
556 	mutex_unlock(&thermal_list_lock);
557 
558 	return ret;
559 }
560 
561 int for_each_thermal_zone(int (*cb)(struct thermal_zone_device *, void *),
562 			  void *data)
563 {
564 	struct thermal_zone_device *tz;
565 	int ret = 0;
566 
567 	mutex_lock(&thermal_list_lock);
568 	list_for_each_entry(tz, &thermal_tz_list, node) {
569 		ret = cb(tz, data);
570 		if (ret)
571 			break;
572 	}
573 	mutex_unlock(&thermal_list_lock);
574 
575 	return ret;
576 }
577 
578 struct thermal_zone_device *thermal_zone_get_by_id(int id)
579 {
580 	struct thermal_zone_device *tz, *match = NULL;
581 
582 	mutex_lock(&thermal_list_lock);
583 	list_for_each_entry(tz, &thermal_tz_list, node) {
584 		if (tz->id == id) {
585 			match = tz;
586 			break;
587 		}
588 	}
589 	mutex_unlock(&thermal_list_lock);
590 
591 	return match;
592 }
593 
594 /*
595  * Device management section: cooling devices, zones devices, and binding
596  *
597  * Set of functions provided by the thermal core for:
598  * - cooling devices lifecycle: registration, unregistration,
599  *				binding, and unbinding.
600  * - thermal zone devices lifecycle: registration, unregistration,
601  *				     binding, and unbinding.
602  */
603 
604 /**
605  * thermal_zone_bind_cooling_device() - bind a cooling device to a thermal zone
606  * @tz:		pointer to struct thermal_zone_device
607  * @trip_index:	indicates which trip point the cooling devices is
608  *		associated with in this thermal zone.
609  * @cdev:	pointer to struct thermal_cooling_device
610  * @upper:	the Maximum cooling state for this trip point.
611  *		THERMAL_NO_LIMIT means no upper limit,
612  *		and the cooling device can be in max_state.
613  * @lower:	the Minimum cooling state can be used for this trip point.
614  *		THERMAL_NO_LIMIT means no lower limit,
615  *		and the cooling device can be in cooling state 0.
616  * @weight:	The weight of the cooling device to be bound to the
617  *		thermal zone. Use THERMAL_WEIGHT_DEFAULT for the
618  *		default value
619  *
620  * This interface function bind a thermal cooling device to the certain trip
621  * point of a thermal zone device.
622  * This function is usually called in the thermal zone device .bind callback.
623  *
624  * Return: 0 on success, the proper error value otherwise.
625  */
626 int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz,
627 				     int trip_index,
628 				     struct thermal_cooling_device *cdev,
629 				     unsigned long upper, unsigned long lower,
630 				     unsigned int weight)
631 {
632 	struct thermal_instance *dev;
633 	struct thermal_instance *pos;
634 	struct thermal_zone_device *pos1;
635 	struct thermal_cooling_device *pos2;
636 	const struct thermal_trip *trip;
637 	bool upper_no_limit;
638 	int result;
639 
640 	if (trip_index >= tz->num_trips || trip_index < 0)
641 		return -EINVAL;
642 
643 	trip = &tz->trips[trip_index];
644 
645 	list_for_each_entry(pos1, &thermal_tz_list, node) {
646 		if (pos1 == tz)
647 			break;
648 	}
649 	list_for_each_entry(pos2, &thermal_cdev_list, node) {
650 		if (pos2 == cdev)
651 			break;
652 	}
653 
654 	if (tz != pos1 || cdev != pos2)
655 		return -EINVAL;
656 
657 	/* lower default 0, upper default max_state */
658 	lower = lower == THERMAL_NO_LIMIT ? 0 : lower;
659 
660 	if (upper == THERMAL_NO_LIMIT) {
661 		upper = cdev->max_state;
662 		upper_no_limit = true;
663 	} else {
664 		upper_no_limit = false;
665 	}
666 
667 	if (lower > upper || upper > cdev->max_state)
668 		return -EINVAL;
669 
670 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
671 	if (!dev)
672 		return -ENOMEM;
673 	dev->tz = tz;
674 	dev->cdev = cdev;
675 	dev->trip = trip;
676 	dev->upper = upper;
677 	dev->upper_no_limit = upper_no_limit;
678 	dev->lower = lower;
679 	dev->target = THERMAL_NO_TARGET;
680 	dev->weight = weight;
681 
682 	result = ida_alloc(&tz->ida, GFP_KERNEL);
683 	if (result < 0)
684 		goto free_mem;
685 
686 	dev->id = result;
687 	sprintf(dev->name, "cdev%d", dev->id);
688 	result =
689 	    sysfs_create_link(&tz->device.kobj, &cdev->device.kobj, dev->name);
690 	if (result)
691 		goto release_ida;
692 
693 	snprintf(dev->attr_name, sizeof(dev->attr_name), "cdev%d_trip_point",
694 		 dev->id);
695 	sysfs_attr_init(&dev->attr.attr);
696 	dev->attr.attr.name = dev->attr_name;
697 	dev->attr.attr.mode = 0444;
698 	dev->attr.show = trip_point_show;
699 	result = device_create_file(&tz->device, &dev->attr);
700 	if (result)
701 		goto remove_symbol_link;
702 
703 	snprintf(dev->weight_attr_name, sizeof(dev->weight_attr_name),
704 		 "cdev%d_weight", dev->id);
705 	sysfs_attr_init(&dev->weight_attr.attr);
706 	dev->weight_attr.attr.name = dev->weight_attr_name;
707 	dev->weight_attr.attr.mode = S_IWUSR | S_IRUGO;
708 	dev->weight_attr.show = weight_show;
709 	dev->weight_attr.store = weight_store;
710 	result = device_create_file(&tz->device, &dev->weight_attr);
711 	if (result)
712 		goto remove_trip_file;
713 
714 	mutex_lock(&tz->lock);
715 	mutex_lock(&cdev->lock);
716 	list_for_each_entry(pos, &tz->thermal_instances, tz_node)
717 		if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
718 			result = -EEXIST;
719 			break;
720 		}
721 	if (!result) {
722 		list_add_tail(&dev->tz_node, &tz->thermal_instances);
723 		list_add_tail(&dev->cdev_node, &cdev->thermal_instances);
724 		atomic_set(&tz->need_update, 1);
725 	}
726 	mutex_unlock(&cdev->lock);
727 	mutex_unlock(&tz->lock);
728 
729 	if (!result)
730 		return 0;
731 
732 	device_remove_file(&tz->device, &dev->weight_attr);
733 remove_trip_file:
734 	device_remove_file(&tz->device, &dev->attr);
735 remove_symbol_link:
736 	sysfs_remove_link(&tz->device.kobj, dev->name);
737 release_ida:
738 	ida_free(&tz->ida, dev->id);
739 free_mem:
740 	kfree(dev);
741 	return result;
742 }
743 EXPORT_SYMBOL_GPL(thermal_zone_bind_cooling_device);
744 
745 /**
746  * thermal_zone_unbind_cooling_device() - unbind a cooling device from a
747  *					  thermal zone.
748  * @tz:		pointer to a struct thermal_zone_device.
749  * @trip_index:	indicates which trip point the cooling devices is
750  *		associated with in this thermal zone.
751  * @cdev:	pointer to a struct thermal_cooling_device.
752  *
753  * This interface function unbind a thermal cooling device from the certain
754  * trip point of a thermal zone device.
755  * This function is usually called in the thermal zone device .unbind callback.
756  *
757  * Return: 0 on success, the proper error value otherwise.
758  */
759 int thermal_zone_unbind_cooling_device(struct thermal_zone_device *tz,
760 				       int trip_index,
761 				       struct thermal_cooling_device *cdev)
762 {
763 	struct thermal_instance *pos, *next;
764 	const struct thermal_trip *trip;
765 
766 	mutex_lock(&tz->lock);
767 	mutex_lock(&cdev->lock);
768 	trip = &tz->trips[trip_index];
769 	list_for_each_entry_safe(pos, next, &tz->thermal_instances, tz_node) {
770 		if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
771 			list_del(&pos->tz_node);
772 			list_del(&pos->cdev_node);
773 			mutex_unlock(&cdev->lock);
774 			mutex_unlock(&tz->lock);
775 			goto unbind;
776 		}
777 	}
778 	mutex_unlock(&cdev->lock);
779 	mutex_unlock(&tz->lock);
780 
781 	return -ENODEV;
782 
783 unbind:
784 	device_remove_file(&tz->device, &pos->weight_attr);
785 	device_remove_file(&tz->device, &pos->attr);
786 	sysfs_remove_link(&tz->device.kobj, pos->name);
787 	ida_free(&tz->ida, pos->id);
788 	kfree(pos);
789 	return 0;
790 }
791 EXPORT_SYMBOL_GPL(thermal_zone_unbind_cooling_device);
792 
793 static void thermal_release(struct device *dev)
794 {
795 	struct thermal_zone_device *tz;
796 	struct thermal_cooling_device *cdev;
797 
798 	if (!strncmp(dev_name(dev), "thermal_zone",
799 		     sizeof("thermal_zone") - 1)) {
800 		tz = to_thermal_zone(dev);
801 		thermal_zone_destroy_device_groups(tz);
802 		mutex_destroy(&tz->lock);
803 		kfree(tz);
804 	} else if (!strncmp(dev_name(dev), "cooling_device",
805 			    sizeof("cooling_device") - 1)) {
806 		cdev = to_cooling_device(dev);
807 		thermal_cooling_device_destroy_sysfs(cdev);
808 		kfree(cdev->type);
809 		ida_free(&thermal_cdev_ida, cdev->id);
810 		kfree(cdev);
811 	}
812 }
813 
814 static struct class *thermal_class;
815 
816 static inline
817 void print_bind_err_msg(struct thermal_zone_device *tz,
818 			struct thermal_cooling_device *cdev, int ret)
819 {
820 	dev_err(&tz->device, "binding zone %s with cdev %s failed:%d\n",
821 		tz->type, cdev->type, ret);
822 }
823 
824 static void bind_cdev(struct thermal_cooling_device *cdev)
825 {
826 	int ret;
827 	struct thermal_zone_device *pos = NULL;
828 
829 	list_for_each_entry(pos, &thermal_tz_list, node) {
830 		if (pos->ops->bind) {
831 			ret = pos->ops->bind(pos, cdev);
832 			if (ret)
833 				print_bind_err_msg(pos, cdev, ret);
834 		}
835 	}
836 }
837 
838 /**
839  * __thermal_cooling_device_register() - register a new thermal cooling device
840  * @np:		a pointer to a device tree node.
841  * @type:	the thermal cooling device type.
842  * @devdata:	device private data.
843  * @ops:		standard thermal cooling devices callbacks.
844  *
845  * This interface function adds a new thermal cooling device (fan/processor/...)
846  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
847  * to all the thermal zone devices registered at the same time.
848  * It also gives the opportunity to link the cooling device to a device tree
849  * node, so that it can be bound to a thermal zone created out of device tree.
850  *
851  * Return: a pointer to the created struct thermal_cooling_device or an
852  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
853  */
854 static struct thermal_cooling_device *
855 __thermal_cooling_device_register(struct device_node *np,
856 				  const char *type, void *devdata,
857 				  const struct thermal_cooling_device_ops *ops)
858 {
859 	struct thermal_cooling_device *cdev;
860 	struct thermal_zone_device *pos = NULL;
861 	int id, ret;
862 
863 	if (!ops || !ops->get_max_state || !ops->get_cur_state ||
864 	    !ops->set_cur_state)
865 		return ERR_PTR(-EINVAL);
866 
867 	if (!thermal_class)
868 		return ERR_PTR(-ENODEV);
869 
870 	cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
871 	if (!cdev)
872 		return ERR_PTR(-ENOMEM);
873 
874 	ret = ida_alloc(&thermal_cdev_ida, GFP_KERNEL);
875 	if (ret < 0)
876 		goto out_kfree_cdev;
877 	cdev->id = ret;
878 	id = ret;
879 
880 	cdev->type = kstrdup(type ? type : "", GFP_KERNEL);
881 	if (!cdev->type) {
882 		ret = -ENOMEM;
883 		goto out_ida_remove;
884 	}
885 
886 	mutex_init(&cdev->lock);
887 	INIT_LIST_HEAD(&cdev->thermal_instances);
888 	cdev->np = np;
889 	cdev->ops = ops;
890 	cdev->updated = false;
891 	cdev->device.class = thermal_class;
892 	cdev->devdata = devdata;
893 
894 	ret = cdev->ops->get_max_state(cdev, &cdev->max_state);
895 	if (ret)
896 		goto out_cdev_type;
897 
898 	thermal_cooling_device_setup_sysfs(cdev);
899 
900 	ret = dev_set_name(&cdev->device, "cooling_device%d", cdev->id);
901 	if (ret)
902 		goto out_cooling_dev;
903 
904 	ret = device_register(&cdev->device);
905 	if (ret) {
906 		/* thermal_release() handles rest of the cleanup */
907 		put_device(&cdev->device);
908 		return ERR_PTR(ret);
909 	}
910 
911 	/* Add 'this' new cdev to the global cdev list */
912 	mutex_lock(&thermal_list_lock);
913 
914 	list_add(&cdev->node, &thermal_cdev_list);
915 
916 	/* Update binding information for 'this' new cdev */
917 	bind_cdev(cdev);
918 
919 	list_for_each_entry(pos, &thermal_tz_list, node)
920 		if (atomic_cmpxchg(&pos->need_update, 1, 0))
921 			thermal_zone_device_update(pos,
922 						   THERMAL_EVENT_UNSPECIFIED);
923 
924 	mutex_unlock(&thermal_list_lock);
925 
926 	return cdev;
927 
928 out_cooling_dev:
929 	thermal_cooling_device_destroy_sysfs(cdev);
930 out_cdev_type:
931 	kfree(cdev->type);
932 out_ida_remove:
933 	ida_free(&thermal_cdev_ida, id);
934 out_kfree_cdev:
935 	kfree(cdev);
936 	return ERR_PTR(ret);
937 }
938 
939 /**
940  * thermal_cooling_device_register() - register a new thermal cooling device
941  * @type:	the thermal cooling device type.
942  * @devdata:	device private data.
943  * @ops:		standard thermal cooling devices callbacks.
944  *
945  * This interface function adds a new thermal cooling device (fan/processor/...)
946  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
947  * to all the thermal zone devices registered at the same time.
948  *
949  * Return: a pointer to the created struct thermal_cooling_device or an
950  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
951  */
952 struct thermal_cooling_device *
953 thermal_cooling_device_register(const char *type, void *devdata,
954 				const struct thermal_cooling_device_ops *ops)
955 {
956 	return __thermal_cooling_device_register(NULL, type, devdata, ops);
957 }
958 EXPORT_SYMBOL_GPL(thermal_cooling_device_register);
959 
960 /**
961  * thermal_of_cooling_device_register() - register an OF thermal cooling device
962  * @np:		a pointer to a device tree node.
963  * @type:	the thermal cooling device type.
964  * @devdata:	device private data.
965  * @ops:		standard thermal cooling devices callbacks.
966  *
967  * This function will register a cooling device with device tree node reference.
968  * This interface function adds a new thermal cooling device (fan/processor/...)
969  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
970  * to all the thermal zone devices registered at the same time.
971  *
972  * Return: a pointer to the created struct thermal_cooling_device or an
973  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
974  */
975 struct thermal_cooling_device *
976 thermal_of_cooling_device_register(struct device_node *np,
977 				   const char *type, void *devdata,
978 				   const struct thermal_cooling_device_ops *ops)
979 {
980 	return __thermal_cooling_device_register(np, type, devdata, ops);
981 }
982 EXPORT_SYMBOL_GPL(thermal_of_cooling_device_register);
983 
984 static void thermal_cooling_device_release(struct device *dev, void *res)
985 {
986 	thermal_cooling_device_unregister(
987 				*(struct thermal_cooling_device **)res);
988 }
989 
990 /**
991  * devm_thermal_of_cooling_device_register() - register an OF thermal cooling
992  *					       device
993  * @dev:	a valid struct device pointer of a sensor device.
994  * @np:		a pointer to a device tree node.
995  * @type:	the thermal cooling device type.
996  * @devdata:	device private data.
997  * @ops:	standard thermal cooling devices callbacks.
998  *
999  * This function will register a cooling device with device tree node reference.
1000  * This interface function adds a new thermal cooling device (fan/processor/...)
1001  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
1002  * to all the thermal zone devices registered at the same time.
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 struct thermal_cooling_device *
1008 devm_thermal_of_cooling_device_register(struct device *dev,
1009 				struct device_node *np,
1010 				char *type, void *devdata,
1011 				const struct thermal_cooling_device_ops *ops)
1012 {
1013 	struct thermal_cooling_device **ptr, *tcd;
1014 
1015 	ptr = devres_alloc(thermal_cooling_device_release, sizeof(*ptr),
1016 			   GFP_KERNEL);
1017 	if (!ptr)
1018 		return ERR_PTR(-ENOMEM);
1019 
1020 	tcd = __thermal_cooling_device_register(np, type, devdata, ops);
1021 	if (IS_ERR(tcd)) {
1022 		devres_free(ptr);
1023 		return tcd;
1024 	}
1025 
1026 	*ptr = tcd;
1027 	devres_add(dev, ptr);
1028 
1029 	return tcd;
1030 }
1031 EXPORT_SYMBOL_GPL(devm_thermal_of_cooling_device_register);
1032 
1033 static bool thermal_cooling_device_present(struct thermal_cooling_device *cdev)
1034 {
1035 	struct thermal_cooling_device *pos = NULL;
1036 
1037 	list_for_each_entry(pos, &thermal_cdev_list, node) {
1038 		if (pos == cdev)
1039 			return true;
1040 	}
1041 
1042 	return false;
1043 }
1044 
1045 /**
1046  * thermal_cooling_device_update - Update a cooling device object
1047  * @cdev: Target cooling device.
1048  *
1049  * Update @cdev to reflect a change of the underlying hardware or platform.
1050  *
1051  * Must be called when the maximum cooling state of @cdev becomes invalid and so
1052  * its .get_max_state() callback needs to be run to produce the new maximum
1053  * cooling state value.
1054  */
1055 void thermal_cooling_device_update(struct thermal_cooling_device *cdev)
1056 {
1057 	struct thermal_instance *ti;
1058 	unsigned long state;
1059 
1060 	if (IS_ERR_OR_NULL(cdev))
1061 		return;
1062 
1063 	/*
1064 	 * Hold thermal_list_lock throughout the update to prevent the device
1065 	 * from going away while being updated.
1066 	 */
1067 	mutex_lock(&thermal_list_lock);
1068 
1069 	if (!thermal_cooling_device_present(cdev))
1070 		goto unlock_list;
1071 
1072 	/*
1073 	 * Update under the cdev lock to prevent the state from being set beyond
1074 	 * the new limit concurrently.
1075 	 */
1076 	mutex_lock(&cdev->lock);
1077 
1078 	if (cdev->ops->get_max_state(cdev, &cdev->max_state))
1079 		goto unlock;
1080 
1081 	thermal_cooling_device_stats_reinit(cdev);
1082 
1083 	list_for_each_entry(ti, &cdev->thermal_instances, cdev_node) {
1084 		if (ti->upper == cdev->max_state)
1085 			continue;
1086 
1087 		if (ti->upper < cdev->max_state) {
1088 			if (ti->upper_no_limit)
1089 				ti->upper = cdev->max_state;
1090 
1091 			continue;
1092 		}
1093 
1094 		ti->upper = cdev->max_state;
1095 		if (ti->lower > ti->upper)
1096 			ti->lower = ti->upper;
1097 
1098 		if (ti->target == THERMAL_NO_TARGET)
1099 			continue;
1100 
1101 		if (ti->target > ti->upper)
1102 			ti->target = ti->upper;
1103 	}
1104 
1105 	if (cdev->ops->get_cur_state(cdev, &state) || state > cdev->max_state)
1106 		goto unlock;
1107 
1108 	thermal_cooling_device_stats_update(cdev, state);
1109 
1110 unlock:
1111 	mutex_unlock(&cdev->lock);
1112 
1113 unlock_list:
1114 	mutex_unlock(&thermal_list_lock);
1115 }
1116 EXPORT_SYMBOL_GPL(thermal_cooling_device_update);
1117 
1118 /**
1119  * thermal_cooling_device_unregister - removes a thermal cooling device
1120  * @cdev:	the thermal cooling device to remove.
1121  *
1122  * thermal_cooling_device_unregister() must be called when a registered
1123  * thermal cooling device is no longer needed.
1124  */
1125 void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev)
1126 {
1127 	struct thermal_zone_device *tz;
1128 
1129 	if (!cdev)
1130 		return;
1131 
1132 	mutex_lock(&thermal_list_lock);
1133 
1134 	if (!thermal_cooling_device_present(cdev)) {
1135 		mutex_unlock(&thermal_list_lock);
1136 		return;
1137 	}
1138 
1139 	list_del(&cdev->node);
1140 
1141 	/* Unbind all thermal zones associated with 'this' cdev */
1142 	list_for_each_entry(tz, &thermal_tz_list, node) {
1143 		if (tz->ops->unbind)
1144 			tz->ops->unbind(tz, cdev);
1145 	}
1146 
1147 	mutex_unlock(&thermal_list_lock);
1148 
1149 	device_unregister(&cdev->device);
1150 }
1151 EXPORT_SYMBOL_GPL(thermal_cooling_device_unregister);
1152 
1153 static void bind_tz(struct thermal_zone_device *tz)
1154 {
1155 	int ret;
1156 	struct thermal_cooling_device *pos = NULL;
1157 
1158 	if (!tz->ops->bind)
1159 		return;
1160 
1161 	mutex_lock(&thermal_list_lock);
1162 
1163 	list_for_each_entry(pos, &thermal_cdev_list, node) {
1164 		ret = tz->ops->bind(tz, pos);
1165 		if (ret)
1166 			print_bind_err_msg(tz, pos, ret);
1167 	}
1168 
1169 	mutex_unlock(&thermal_list_lock);
1170 }
1171 
1172 static void thermal_set_delay_jiffies(unsigned long *delay_jiffies, int delay_ms)
1173 {
1174 	*delay_jiffies = msecs_to_jiffies(delay_ms);
1175 	if (delay_ms > 1000)
1176 		*delay_jiffies = round_jiffies(*delay_jiffies);
1177 }
1178 
1179 int thermal_zone_get_crit_temp(struct thermal_zone_device *tz, int *temp)
1180 {
1181 	int i, ret = -EINVAL;
1182 
1183 	if (tz->ops->get_crit_temp)
1184 		return tz->ops->get_crit_temp(tz, temp);
1185 
1186 	if (!tz->trips)
1187 		return -EINVAL;
1188 
1189 	mutex_lock(&tz->lock);
1190 
1191 	for (i = 0; i < tz->num_trips; i++) {
1192 		if (tz->trips[i].type == THERMAL_TRIP_CRITICAL) {
1193 			*temp = tz->trips[i].temperature;
1194 			ret = 0;
1195 			break;
1196 		}
1197 	}
1198 
1199 	mutex_unlock(&tz->lock);
1200 
1201 	return ret;
1202 }
1203 EXPORT_SYMBOL_GPL(thermal_zone_get_crit_temp);
1204 
1205 /**
1206  * thermal_zone_device_register_with_trips() - register a new thermal zone device
1207  * @type:	the thermal zone device type
1208  * @trips:	a pointer to an array of thermal trips
1209  * @num_trips:	the number of trip points the thermal zone support
1210  * @mask:	a bit string indicating the writeablility of trip points
1211  * @devdata:	private device data
1212  * @ops:	standard thermal zone device callbacks
1213  * @tzp:	thermal zone platform parameters
1214  * @passive_delay: number of milliseconds to wait between polls when
1215  *		   performing passive cooling
1216  * @polling_delay: number of milliseconds to wait between polls when checking
1217  *		   whether trip points have been crossed (0 for interrupt
1218  *		   driven systems)
1219  *
1220  * This interface function adds a new thermal zone device (sensor) to
1221  * /sys/class/thermal folder as thermal_zone[0-*]. It tries to bind all the
1222  * thermal cooling devices registered at the same time.
1223  * thermal_zone_device_unregister() must be called when the device is no
1224  * longer needed. The passive cooling depends on the .get_trend() return value.
1225  *
1226  * Return: a pointer to the created struct thermal_zone_device or an
1227  * in case of error, an ERR_PTR. Caller must check return value with
1228  * IS_ERR*() helpers.
1229  */
1230 struct thermal_zone_device *
1231 thermal_zone_device_register_with_trips(const char *type, struct thermal_trip *trips, int num_trips, int mask,
1232 					void *devdata, struct thermal_zone_device_ops *ops,
1233 					const struct thermal_zone_params *tzp, int passive_delay,
1234 					int polling_delay)
1235 {
1236 	struct thermal_zone_device *tz;
1237 	int id;
1238 	int result;
1239 	int count;
1240 	struct thermal_governor *governor;
1241 
1242 	if (!type || strlen(type) == 0) {
1243 		pr_err("No thermal zone type defined\n");
1244 		return ERR_PTR(-EINVAL);
1245 	}
1246 
1247 	if (strlen(type) >= THERMAL_NAME_LENGTH) {
1248 		pr_err("Thermal zone name (%s) too long, should be under %d chars\n",
1249 		       type, THERMAL_NAME_LENGTH);
1250 		return ERR_PTR(-EINVAL);
1251 	}
1252 
1253 	/*
1254 	 * Max trip count can't exceed 31 as the "mask >> num_trips" condition.
1255 	 * For example, shifting by 32 will result in compiler warning:
1256 	 * warning: right shift count >= width of type [-Wshift-count- overflow]
1257 	 *
1258 	 * Also "mask >> num_trips" will always be true with 32 bit shift.
1259 	 * E.g. mask = 0x80000000 for trip id 31 to be RW. Then
1260 	 * mask >> 32 = 0x80000000
1261 	 * This will result in failure for the below condition.
1262 	 *
1263 	 * Check will be true when the bit 31 of the mask is set.
1264 	 * 32 bit shift will cause overflow of 4 byte integer.
1265 	 */
1266 	if (num_trips > (BITS_PER_TYPE(int) - 1) || num_trips < 0 || mask >> num_trips) {
1267 		pr_err("Incorrect number of thermal trips\n");
1268 		return ERR_PTR(-EINVAL);
1269 	}
1270 
1271 	if (!ops) {
1272 		pr_err("Thermal zone device ops not defined\n");
1273 		return ERR_PTR(-EINVAL);
1274 	}
1275 
1276 	if (num_trips > 0 && !trips)
1277 		return ERR_PTR(-EINVAL);
1278 
1279 	if (!thermal_class)
1280 		return ERR_PTR(-ENODEV);
1281 
1282 	tz = kzalloc(sizeof(*tz), GFP_KERNEL);
1283 	if (!tz)
1284 		return ERR_PTR(-ENOMEM);
1285 
1286 	if (tzp) {
1287 		tz->tzp = kmemdup(tzp, sizeof(*tzp), GFP_KERNEL);
1288 		if (!tz->tzp) {
1289 			result = -ENOMEM;
1290 			goto free_tz;
1291 		}
1292 	}
1293 
1294 	INIT_LIST_HEAD(&tz->thermal_instances);
1295 	ida_init(&tz->ida);
1296 	mutex_init(&tz->lock);
1297 	id = ida_alloc(&thermal_tz_ida, GFP_KERNEL);
1298 	if (id < 0) {
1299 		result = id;
1300 		goto free_tzp;
1301 	}
1302 
1303 	tz->id = id;
1304 	strscpy(tz->type, type, sizeof(tz->type));
1305 
1306 	if (!ops->critical)
1307 		ops->critical = thermal_zone_device_critical;
1308 
1309 	tz->ops = ops;
1310 	tz->device.class = thermal_class;
1311 	tz->devdata = devdata;
1312 	tz->trips = trips;
1313 	tz->num_trips = num_trips;
1314 
1315 	thermal_set_delay_jiffies(&tz->passive_delay_jiffies, passive_delay);
1316 	thermal_set_delay_jiffies(&tz->polling_delay_jiffies, polling_delay);
1317 
1318 	/* sys I/F */
1319 	/* Add nodes that are always present via .groups */
1320 	result = thermal_zone_create_device_groups(tz, mask);
1321 	if (result)
1322 		goto remove_id;
1323 
1324 	/* A new thermal zone needs to be updated anyway. */
1325 	atomic_set(&tz->need_update, 1);
1326 
1327 	result = dev_set_name(&tz->device, "thermal_zone%d", tz->id);
1328 	if (result) {
1329 		thermal_zone_destroy_device_groups(tz);
1330 		goto remove_id;
1331 	}
1332 	result = device_register(&tz->device);
1333 	if (result)
1334 		goto release_device;
1335 
1336 	for (count = 0; count < num_trips; count++) {
1337 		struct thermal_trip trip;
1338 
1339 		result = thermal_zone_get_trip(tz, count, &trip);
1340 		if (result || !trip.temperature)
1341 			set_bit(count, &tz->trips_disabled);
1342 	}
1343 
1344 	/* Update 'this' zone's governor information */
1345 	mutex_lock(&thermal_governor_lock);
1346 
1347 	if (tz->tzp)
1348 		governor = __find_governor(tz->tzp->governor_name);
1349 	else
1350 		governor = def_governor;
1351 
1352 	result = thermal_set_governor(tz, governor);
1353 	if (result) {
1354 		mutex_unlock(&thermal_governor_lock);
1355 		goto unregister;
1356 	}
1357 
1358 	mutex_unlock(&thermal_governor_lock);
1359 
1360 	if (!tz->tzp || !tz->tzp->no_hwmon) {
1361 		result = thermal_add_hwmon_sysfs(tz);
1362 		if (result)
1363 			goto unregister;
1364 	}
1365 
1366 	mutex_lock(&thermal_list_lock);
1367 	list_add_tail(&tz->node, &thermal_tz_list);
1368 	mutex_unlock(&thermal_list_lock);
1369 
1370 	/* Bind cooling devices for this zone */
1371 	bind_tz(tz);
1372 
1373 	INIT_DELAYED_WORK(&tz->poll_queue, thermal_zone_device_check);
1374 
1375 	thermal_zone_device_init(tz);
1376 	/* Update the new thermal zone and mark it as already updated. */
1377 	if (atomic_cmpxchg(&tz->need_update, 1, 0))
1378 		thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
1379 
1380 	thermal_notify_tz_create(tz->id, tz->type);
1381 
1382 	return tz;
1383 
1384 unregister:
1385 	device_del(&tz->device);
1386 release_device:
1387 	put_device(&tz->device);
1388 remove_id:
1389 	ida_free(&thermal_tz_ida, id);
1390 free_tzp:
1391 	kfree(tz->tzp);
1392 free_tz:
1393 	kfree(tz);
1394 	return ERR_PTR(result);
1395 }
1396 EXPORT_SYMBOL_GPL(thermal_zone_device_register_with_trips);
1397 
1398 struct thermal_zone_device *thermal_tripless_zone_device_register(
1399 					const char *type,
1400 					void *devdata,
1401 					struct thermal_zone_device_ops *ops,
1402 					const struct thermal_zone_params *tzp)
1403 {
1404 	return thermal_zone_device_register_with_trips(type, NULL, 0, 0, devdata,
1405 						       ops, tzp, 0, 0);
1406 }
1407 EXPORT_SYMBOL_GPL(thermal_tripless_zone_device_register);
1408 
1409 void *thermal_zone_device_priv(struct thermal_zone_device *tzd)
1410 {
1411 	return tzd->devdata;
1412 }
1413 EXPORT_SYMBOL_GPL(thermal_zone_device_priv);
1414 
1415 const char *thermal_zone_device_type(struct thermal_zone_device *tzd)
1416 {
1417 	return tzd->type;
1418 }
1419 EXPORT_SYMBOL_GPL(thermal_zone_device_type);
1420 
1421 int thermal_zone_device_id(struct thermal_zone_device *tzd)
1422 {
1423 	return tzd->id;
1424 }
1425 EXPORT_SYMBOL_GPL(thermal_zone_device_id);
1426 
1427 struct device *thermal_zone_device(struct thermal_zone_device *tzd)
1428 {
1429 	return &tzd->device;
1430 }
1431 EXPORT_SYMBOL_GPL(thermal_zone_device);
1432 
1433 /**
1434  * thermal_zone_device_unregister - removes the registered thermal zone device
1435  * @tz: the thermal zone device to remove
1436  */
1437 void thermal_zone_device_unregister(struct thermal_zone_device *tz)
1438 {
1439 	int tz_id;
1440 	struct thermal_cooling_device *cdev;
1441 	struct thermal_zone_device *pos = NULL;
1442 
1443 	if (!tz)
1444 		return;
1445 
1446 	tz_id = tz->id;
1447 
1448 	mutex_lock(&thermal_list_lock);
1449 	list_for_each_entry(pos, &thermal_tz_list, node)
1450 		if (pos == tz)
1451 			break;
1452 	if (pos != tz) {
1453 		/* thermal zone device not found */
1454 		mutex_unlock(&thermal_list_lock);
1455 		return;
1456 	}
1457 	list_del(&tz->node);
1458 
1459 	/* Unbind all cdevs associated with 'this' thermal zone */
1460 	list_for_each_entry(cdev, &thermal_cdev_list, node)
1461 		if (tz->ops->unbind)
1462 			tz->ops->unbind(tz, cdev);
1463 
1464 	mutex_unlock(&thermal_list_lock);
1465 
1466 	cancel_delayed_work_sync(&tz->poll_queue);
1467 
1468 	thermal_set_governor(tz, NULL);
1469 
1470 	thermal_remove_hwmon_sysfs(tz);
1471 	ida_free(&thermal_tz_ida, tz->id);
1472 	ida_destroy(&tz->ida);
1473 
1474 	mutex_lock(&tz->lock);
1475 	device_del(&tz->device);
1476 	mutex_unlock(&tz->lock);
1477 
1478 	kfree(tz->tzp);
1479 
1480 	put_device(&tz->device);
1481 
1482 	thermal_notify_tz_delete(tz_id);
1483 }
1484 EXPORT_SYMBOL_GPL(thermal_zone_device_unregister);
1485 
1486 /**
1487  * thermal_zone_get_zone_by_name() - search for a zone and returns its ref
1488  * @name: thermal zone name to fetch the temperature
1489  *
1490  * When only one zone is found with the passed name, returns a reference to it.
1491  *
1492  * Return: On success returns a reference to an unique thermal zone with
1493  * matching name equals to @name, an ERR_PTR otherwise (-EINVAL for invalid
1494  * paramenters, -ENODEV for not found and -EEXIST for multiple matches).
1495  */
1496 struct thermal_zone_device *thermal_zone_get_zone_by_name(const char *name)
1497 {
1498 	struct thermal_zone_device *pos = NULL, *ref = ERR_PTR(-EINVAL);
1499 	unsigned int found = 0;
1500 
1501 	if (!name)
1502 		goto exit;
1503 
1504 	mutex_lock(&thermal_list_lock);
1505 	list_for_each_entry(pos, &thermal_tz_list, node)
1506 		if (!strncasecmp(name, pos->type, THERMAL_NAME_LENGTH)) {
1507 			found++;
1508 			ref = pos;
1509 		}
1510 	mutex_unlock(&thermal_list_lock);
1511 
1512 	/* nothing has been found, thus an error code for it */
1513 	if (found == 0)
1514 		ref = ERR_PTR(-ENODEV);
1515 	else if (found > 1)
1516 	/* Success only when an unique zone is found */
1517 		ref = ERR_PTR(-EEXIST);
1518 
1519 exit:
1520 	return ref;
1521 }
1522 EXPORT_SYMBOL_GPL(thermal_zone_get_zone_by_name);
1523 
1524 static int thermal_pm_notify(struct notifier_block *nb,
1525 			     unsigned long mode, void *_unused)
1526 {
1527 	struct thermal_zone_device *tz;
1528 
1529 	switch (mode) {
1530 	case PM_HIBERNATION_PREPARE:
1531 	case PM_RESTORE_PREPARE:
1532 	case PM_SUSPEND_PREPARE:
1533 		mutex_lock(&thermal_list_lock);
1534 
1535 		list_for_each_entry(tz, &thermal_tz_list, node) {
1536 			mutex_lock(&tz->lock);
1537 
1538 			tz->suspended = true;
1539 
1540 			mutex_unlock(&tz->lock);
1541 		}
1542 
1543 		mutex_unlock(&thermal_list_lock);
1544 		break;
1545 	case PM_POST_HIBERNATION:
1546 	case PM_POST_RESTORE:
1547 	case PM_POST_SUSPEND:
1548 		mutex_lock(&thermal_list_lock);
1549 
1550 		list_for_each_entry(tz, &thermal_tz_list, node) {
1551 			mutex_lock(&tz->lock);
1552 
1553 			tz->suspended = false;
1554 
1555 			thermal_zone_device_init(tz);
1556 			__thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
1557 
1558 			mutex_unlock(&tz->lock);
1559 		}
1560 
1561 		mutex_unlock(&thermal_list_lock);
1562 		break;
1563 	default:
1564 		break;
1565 	}
1566 	return 0;
1567 }
1568 
1569 static struct notifier_block thermal_pm_nb = {
1570 	.notifier_call = thermal_pm_notify,
1571 };
1572 
1573 static int __init thermal_init(void)
1574 {
1575 	int result;
1576 
1577 	result = thermal_netlink_init();
1578 	if (result)
1579 		goto error;
1580 
1581 	result = thermal_register_governors();
1582 	if (result)
1583 		goto unregister_netlink;
1584 
1585 	thermal_class = kzalloc(sizeof(*thermal_class), GFP_KERNEL);
1586 	if (!thermal_class) {
1587 		result = -ENOMEM;
1588 		goto unregister_governors;
1589 	}
1590 
1591 	thermal_class->name = "thermal";
1592 	thermal_class->dev_release = thermal_release;
1593 
1594 	result = class_register(thermal_class);
1595 	if (result) {
1596 		kfree(thermal_class);
1597 		thermal_class = NULL;
1598 		goto unregister_governors;
1599 	}
1600 
1601 	result = register_pm_notifier(&thermal_pm_nb);
1602 	if (result)
1603 		pr_warn("Thermal: Can not register suspend notifier, return %d\n",
1604 			result);
1605 
1606 	return 0;
1607 
1608 unregister_governors:
1609 	thermal_unregister_governors();
1610 unregister_netlink:
1611 	thermal_netlink_exit();
1612 error:
1613 	mutex_destroy(&thermal_list_lock);
1614 	mutex_destroy(&thermal_governor_lock);
1615 	return result;
1616 }
1617 postcore_initcall(thermal_init);
1618