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 
40 static atomic_t in_suspend;
41 
42 static struct thermal_governor *def_governor;
43 
44 /*
45  * Governor section: set of functions to handle thermal governors
46  *
47  * Functions to help in the life cycle of thermal governors within
48  * the thermal core and by the thermal governor code.
49  */
50 
51 static struct thermal_governor *__find_governor(const char *name)
52 {
53 	struct thermal_governor *pos;
54 
55 	if (!name || !name[0])
56 		return def_governor;
57 
58 	list_for_each_entry(pos, &thermal_governor_list, governor_list)
59 		if (!strncasecmp(name, pos->name, THERMAL_NAME_LENGTH))
60 			return pos;
61 
62 	return NULL;
63 }
64 
65 /**
66  * bind_previous_governor() - bind the previous governor of the thermal zone
67  * @tz:		a valid pointer to a struct thermal_zone_device
68  * @failed_gov_name:	the name of the governor that failed to register
69  *
70  * Register the previous governor of the thermal zone after a new
71  * governor has failed to be bound.
72  */
73 static void bind_previous_governor(struct thermal_zone_device *tz,
74 				   const char *failed_gov_name)
75 {
76 	if (tz->governor && tz->governor->bind_to_tz) {
77 		if (tz->governor->bind_to_tz(tz)) {
78 			dev_err(&tz->device,
79 				"governor %s failed to bind and the previous one (%s) failed to bind again, thermal zone %s has no governor\n",
80 				failed_gov_name, tz->governor->name, tz->type);
81 			tz->governor = NULL;
82 		}
83 	}
84 }
85 
86 /**
87  * thermal_set_governor() - Switch to another governor
88  * @tz:		a valid pointer to a struct thermal_zone_device
89  * @new_gov:	pointer to the new governor
90  *
91  * Change the governor of thermal zone @tz.
92  *
93  * Return: 0 on success, an error if the new governor's bind_to_tz() failed.
94  */
95 static int thermal_set_governor(struct thermal_zone_device *tz,
96 				struct thermal_governor *new_gov)
97 {
98 	int ret = 0;
99 
100 	if (tz->governor && tz->governor->unbind_from_tz)
101 		tz->governor->unbind_from_tz(tz);
102 
103 	if (new_gov && new_gov->bind_to_tz) {
104 		ret = new_gov->bind_to_tz(tz);
105 		if (ret) {
106 			bind_previous_governor(tz, new_gov->name);
107 
108 			return ret;
109 		}
110 	}
111 
112 	tz->governor = new_gov;
113 
114 	return ret;
115 }
116 
117 int thermal_register_governor(struct thermal_governor *governor)
118 {
119 	int err;
120 	const char *name;
121 	struct thermal_zone_device *pos;
122 
123 	if (!governor)
124 		return -EINVAL;
125 
126 	mutex_lock(&thermal_governor_lock);
127 
128 	err = -EBUSY;
129 	if (!__find_governor(governor->name)) {
130 		bool match_default;
131 
132 		err = 0;
133 		list_add(&governor->governor_list, &thermal_governor_list);
134 		match_default = !strncmp(governor->name,
135 					 DEFAULT_THERMAL_GOVERNOR,
136 					 THERMAL_NAME_LENGTH);
137 
138 		if (!def_governor && match_default)
139 			def_governor = governor;
140 	}
141 
142 	mutex_lock(&thermal_list_lock);
143 
144 	list_for_each_entry(pos, &thermal_tz_list, node) {
145 		/*
146 		 * only thermal zones with specified tz->tzp->governor_name
147 		 * may run with tz->govenor unset
148 		 */
149 		if (pos->governor)
150 			continue;
151 
152 		name = pos->tzp->governor_name;
153 
154 		if (!strncasecmp(name, governor->name, THERMAL_NAME_LENGTH)) {
155 			int ret;
156 
157 			ret = thermal_set_governor(pos, governor);
158 			if (ret)
159 				dev_err(&pos->device,
160 					"Failed to set governor %s for thermal zone %s: %d\n",
161 					governor->name, pos->type, ret);
162 		}
163 	}
164 
165 	mutex_unlock(&thermal_list_lock);
166 	mutex_unlock(&thermal_governor_lock);
167 
168 	return err;
169 }
170 
171 void thermal_unregister_governor(struct thermal_governor *governor)
172 {
173 	struct thermal_zone_device *pos;
174 
175 	if (!governor)
176 		return;
177 
178 	mutex_lock(&thermal_governor_lock);
179 
180 	if (!__find_governor(governor->name))
181 		goto exit;
182 
183 	mutex_lock(&thermal_list_lock);
184 
185 	list_for_each_entry(pos, &thermal_tz_list, node) {
186 		if (!strncasecmp(pos->governor->name, governor->name,
187 				 THERMAL_NAME_LENGTH))
188 			thermal_set_governor(pos, NULL);
189 	}
190 
191 	mutex_unlock(&thermal_list_lock);
192 	list_del(&governor->governor_list);
193 exit:
194 	mutex_unlock(&thermal_governor_lock);
195 }
196 
197 int thermal_zone_device_set_policy(struct thermal_zone_device *tz,
198 				   char *policy)
199 {
200 	struct thermal_governor *gov;
201 	int ret = -EINVAL;
202 
203 	mutex_lock(&thermal_governor_lock);
204 	mutex_lock(&tz->lock);
205 
206 	if (!device_is_registered(&tz->device))
207 		goto exit;
208 
209 	gov = __find_governor(strim(policy));
210 	if (!gov)
211 		goto exit;
212 
213 	ret = thermal_set_governor(tz, gov);
214 
215 exit:
216 	mutex_unlock(&tz->lock);
217 	mutex_unlock(&thermal_governor_lock);
218 
219 	thermal_notify_tz_gov_change(tz->id, policy);
220 
221 	return ret;
222 }
223 
224 int thermal_build_list_of_policies(char *buf)
225 {
226 	struct thermal_governor *pos;
227 	ssize_t count = 0;
228 
229 	mutex_lock(&thermal_governor_lock);
230 
231 	list_for_each_entry(pos, &thermal_governor_list, governor_list) {
232 		count += sysfs_emit_at(buf, count, "%s ", pos->name);
233 	}
234 	count += sysfs_emit_at(buf, count, "\n");
235 
236 	mutex_unlock(&thermal_governor_lock);
237 
238 	return count;
239 }
240 
241 static void __init thermal_unregister_governors(void)
242 {
243 	struct thermal_governor **governor;
244 
245 	for_each_governor_table(governor)
246 		thermal_unregister_governor(*governor);
247 }
248 
249 static int __init thermal_register_governors(void)
250 {
251 	int ret = 0;
252 	struct thermal_governor **governor;
253 
254 	for_each_governor_table(governor) {
255 		ret = thermal_register_governor(*governor);
256 		if (ret) {
257 			pr_err("Failed to register governor: '%s'",
258 			       (*governor)->name);
259 			break;
260 		}
261 
262 		pr_info("Registered thermal governor '%s'",
263 			(*governor)->name);
264 	}
265 
266 	if (ret) {
267 		struct thermal_governor **gov;
268 
269 		for_each_governor_table(gov) {
270 			if (gov == governor)
271 				break;
272 			thermal_unregister_governor(*gov);
273 		}
274 	}
275 
276 	return ret;
277 }
278 
279 /*
280  * Zone update section: main control loop applied to each zone while monitoring
281  *
282  * in polling mode. The monitoring is done using a workqueue.
283  * Same update may be done on a zone by calling thermal_zone_device_update().
284  *
285  * An update means:
286  * - Non-critical trips will invoke the governor responsible for that zone;
287  * - Hot trips will produce a notification to userspace;
288  * - Critical trip point will cause a system shutdown.
289  */
290 static void thermal_zone_device_set_polling(struct thermal_zone_device *tz,
291 					    unsigned long delay)
292 {
293 	if (delay)
294 		mod_delayed_work(system_freezable_power_efficient_wq,
295 				 &tz->poll_queue, delay);
296 	else
297 		cancel_delayed_work(&tz->poll_queue);
298 }
299 
300 static void monitor_thermal_zone(struct thermal_zone_device *tz)
301 {
302 	if (tz->mode != THERMAL_DEVICE_ENABLED)
303 		thermal_zone_device_set_polling(tz, 0);
304 	else if (tz->passive)
305 		thermal_zone_device_set_polling(tz, tz->passive_delay_jiffies);
306 	else if (tz->polling_delay_jiffies)
307 		thermal_zone_device_set_polling(tz, tz->polling_delay_jiffies);
308 }
309 
310 static void handle_non_critical_trips(struct thermal_zone_device *tz, int trip)
311 {
312 	tz->governor ? tz->governor->throttle(tz, trip) :
313 		       def_governor->throttle(tz, trip);
314 }
315 
316 void thermal_zone_device_critical(struct thermal_zone_device *tz)
317 {
318 	/*
319 	 * poweroff_delay_ms must be a carefully profiled positive value.
320 	 * Its a must for forced_emergency_poweroff_work to be scheduled.
321 	 */
322 	int poweroff_delay_ms = CONFIG_THERMAL_EMERGENCY_POWEROFF_DELAY_MS;
323 
324 	dev_emerg(&tz->device, "%s: critical temperature reached, "
325 		  "shutting down\n", tz->type);
326 
327 	hw_protection_shutdown("Temperature too high", poweroff_delay_ms);
328 }
329 EXPORT_SYMBOL(thermal_zone_device_critical);
330 
331 static void handle_critical_trips(struct thermal_zone_device *tz,
332 				  int trip, int trip_temp, enum thermal_trip_type trip_type)
333 {
334 	/* If we have not crossed the trip_temp, we do not care. */
335 	if (trip_temp <= 0 || tz->temperature < trip_temp)
336 		return;
337 
338 	trace_thermal_zone_trip(tz, trip, trip_type);
339 
340 	if (trip_type == THERMAL_TRIP_HOT && tz->ops->hot)
341 		tz->ops->hot(tz);
342 	else if (trip_type == THERMAL_TRIP_CRITICAL)
343 		tz->ops->critical(tz);
344 }
345 
346 static void handle_thermal_trip(struct thermal_zone_device *tz, int trip_id)
347 {
348 	struct thermal_trip trip;
349 
350 	/* Ignore disabled trip points */
351 	if (test_bit(trip_id, &tz->trips_disabled))
352 		return;
353 
354 	__thermal_zone_get_trip(tz, trip_id, &trip);
355 
356 	if (tz->last_temperature != THERMAL_TEMP_INVALID) {
357 		if (tz->last_temperature < trip.temperature &&
358 		    tz->temperature >= trip.temperature)
359 			thermal_notify_tz_trip_up(tz->id, trip_id,
360 						  tz->temperature);
361 		if (tz->last_temperature >= trip.temperature &&
362 		    tz->temperature < (trip.temperature - trip.hysteresis))
363 			thermal_notify_tz_trip_down(tz->id, trip_id,
364 						    tz->temperature);
365 	}
366 
367 	if (trip.type == THERMAL_TRIP_CRITICAL || trip.type == THERMAL_TRIP_HOT)
368 		handle_critical_trips(tz, trip_id, trip.temperature, trip.type);
369 	else
370 		handle_non_critical_trips(tz, trip_id);
371 }
372 
373 static void update_temperature(struct thermal_zone_device *tz)
374 {
375 	int temp, ret;
376 
377 	ret = __thermal_zone_get_temp(tz, &temp);
378 	if (ret) {
379 		if (ret != -EAGAIN)
380 			dev_warn(&tz->device,
381 				 "failed to read out thermal zone (%d)\n",
382 				 ret);
383 		return;
384 	}
385 
386 	tz->last_temperature = tz->temperature;
387 	tz->temperature = temp;
388 
389 	trace_thermal_temperature(tz);
390 
391 	thermal_genl_sampling_temp(tz->id, temp);
392 }
393 
394 static void thermal_zone_device_init(struct thermal_zone_device *tz)
395 {
396 	struct thermal_instance *pos;
397 	tz->temperature = THERMAL_TEMP_INVALID;
398 	tz->prev_low_trip = -INT_MAX;
399 	tz->prev_high_trip = INT_MAX;
400 	list_for_each_entry(pos, &tz->thermal_instances, tz_node)
401 		pos->initialized = false;
402 }
403 
404 void __thermal_zone_device_update(struct thermal_zone_device *tz,
405 				  enum thermal_notify_event event)
406 {
407 	int count;
408 
409 	if (atomic_read(&in_suspend))
410 		return;
411 
412 	if (WARN_ONCE(!tz->ops->get_temp,
413 		      "'%s' must not be called without 'get_temp' ops set\n",
414 		      __func__))
415 		return;
416 
417 	if (!thermal_zone_device_is_enabled(tz))
418 		return;
419 
420 	update_temperature(tz);
421 
422 	__thermal_zone_set_trips(tz);
423 
424 	tz->notify_event = event;
425 
426 	for (count = 0; count < tz->num_trips; count++)
427 		handle_thermal_trip(tz, count);
428 
429 	monitor_thermal_zone(tz);
430 }
431 
432 static int thermal_zone_device_set_mode(struct thermal_zone_device *tz,
433 					enum thermal_device_mode mode)
434 {
435 	int ret = 0;
436 
437 	mutex_lock(&tz->lock);
438 
439 	/* do nothing if mode isn't changing */
440 	if (mode == tz->mode) {
441 		mutex_unlock(&tz->lock);
442 
443 		return ret;
444 	}
445 
446 	if (!device_is_registered(&tz->device)) {
447 		mutex_unlock(&tz->lock);
448 
449 		return -ENODEV;
450 	}
451 
452 	if (tz->ops->change_mode)
453 		ret = tz->ops->change_mode(tz, mode);
454 
455 	if (!ret)
456 		tz->mode = mode;
457 
458 	__thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
459 
460 	mutex_unlock(&tz->lock);
461 
462 	if (mode == THERMAL_DEVICE_ENABLED)
463 		thermal_notify_tz_enable(tz->id);
464 	else
465 		thermal_notify_tz_disable(tz->id);
466 
467 	return ret;
468 }
469 
470 int thermal_zone_device_enable(struct thermal_zone_device *tz)
471 {
472 	return thermal_zone_device_set_mode(tz, THERMAL_DEVICE_ENABLED);
473 }
474 EXPORT_SYMBOL_GPL(thermal_zone_device_enable);
475 
476 int thermal_zone_device_disable(struct thermal_zone_device *tz)
477 {
478 	return thermal_zone_device_set_mode(tz, THERMAL_DEVICE_DISABLED);
479 }
480 EXPORT_SYMBOL_GPL(thermal_zone_device_disable);
481 
482 int thermal_zone_device_is_enabled(struct thermal_zone_device *tz)
483 {
484 	lockdep_assert_held(&tz->lock);
485 
486 	return tz->mode == THERMAL_DEVICE_ENABLED;
487 }
488 
489 void thermal_zone_device_update(struct thermal_zone_device *tz,
490 				enum thermal_notify_event event)
491 {
492 	mutex_lock(&tz->lock);
493 	if (device_is_registered(&tz->device))
494 		__thermal_zone_device_update(tz, event);
495 	mutex_unlock(&tz->lock);
496 }
497 EXPORT_SYMBOL_GPL(thermal_zone_device_update);
498 
499 static void thermal_zone_device_check(struct work_struct *work)
500 {
501 	struct thermal_zone_device *tz = container_of(work, struct
502 						      thermal_zone_device,
503 						      poll_queue.work);
504 	thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
505 }
506 
507 int for_each_thermal_governor(int (*cb)(struct thermal_governor *, void *),
508 			      void *data)
509 {
510 	struct thermal_governor *gov;
511 	int ret = 0;
512 
513 	mutex_lock(&thermal_governor_lock);
514 	list_for_each_entry(gov, &thermal_governor_list, governor_list) {
515 		ret = cb(gov, data);
516 		if (ret)
517 			break;
518 	}
519 	mutex_unlock(&thermal_governor_lock);
520 
521 	return ret;
522 }
523 
524 int for_each_thermal_cooling_device(int (*cb)(struct thermal_cooling_device *,
525 					      void *), void *data)
526 {
527 	struct thermal_cooling_device *cdev;
528 	int ret = 0;
529 
530 	mutex_lock(&thermal_list_lock);
531 	list_for_each_entry(cdev, &thermal_cdev_list, node) {
532 		ret = cb(cdev, data);
533 		if (ret)
534 			break;
535 	}
536 	mutex_unlock(&thermal_list_lock);
537 
538 	return ret;
539 }
540 
541 int for_each_thermal_zone(int (*cb)(struct thermal_zone_device *, void *),
542 			  void *data)
543 {
544 	struct thermal_zone_device *tz;
545 	int ret = 0;
546 
547 	mutex_lock(&thermal_list_lock);
548 	list_for_each_entry(tz, &thermal_tz_list, node) {
549 		ret = cb(tz, data);
550 		if (ret)
551 			break;
552 	}
553 	mutex_unlock(&thermal_list_lock);
554 
555 	return ret;
556 }
557 
558 struct thermal_zone_device *thermal_zone_get_by_id(int id)
559 {
560 	struct thermal_zone_device *tz, *match = NULL;
561 
562 	mutex_lock(&thermal_list_lock);
563 	list_for_each_entry(tz, &thermal_tz_list, node) {
564 		if (tz->id == id) {
565 			match = tz;
566 			break;
567 		}
568 	}
569 	mutex_unlock(&thermal_list_lock);
570 
571 	return match;
572 }
573 
574 /*
575  * Device management section: cooling devices, zones devices, and binding
576  *
577  * Set of functions provided by the thermal core for:
578  * - cooling devices lifecycle: registration, unregistration,
579  *				binding, and unbinding.
580  * - thermal zone devices lifecycle: registration, unregistration,
581  *				     binding, and unbinding.
582  */
583 
584 /**
585  * thermal_zone_bind_cooling_device() - bind a cooling device to a thermal zone
586  * @tz:		pointer to struct thermal_zone_device
587  * @trip:	indicates which trip point the cooling devices is
588  *		associated with in this thermal zone.
589  * @cdev:	pointer to struct thermal_cooling_device
590  * @upper:	the Maximum cooling state for this trip point.
591  *		THERMAL_NO_LIMIT means no upper limit,
592  *		and the cooling device can be in max_state.
593  * @lower:	the Minimum cooling state can be used for this trip point.
594  *		THERMAL_NO_LIMIT means no lower limit,
595  *		and the cooling device can be in cooling state 0.
596  * @weight:	The weight of the cooling device to be bound to the
597  *		thermal zone. Use THERMAL_WEIGHT_DEFAULT for the
598  *		default value
599  *
600  * This interface function bind a thermal cooling device to the certain trip
601  * point of a thermal zone device.
602  * This function is usually called in the thermal zone device .bind callback.
603  *
604  * Return: 0 on success, the proper error value otherwise.
605  */
606 int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz,
607 				     int trip,
608 				     struct thermal_cooling_device *cdev,
609 				     unsigned long upper, unsigned long lower,
610 				     unsigned int weight)
611 {
612 	struct thermal_instance *dev;
613 	struct thermal_instance *pos;
614 	struct thermal_zone_device *pos1;
615 	struct thermal_cooling_device *pos2;
616 	bool upper_no_limit;
617 	int result;
618 
619 	if (trip >= tz->num_trips || trip < 0)
620 		return -EINVAL;
621 
622 	list_for_each_entry(pos1, &thermal_tz_list, node) {
623 		if (pos1 == tz)
624 			break;
625 	}
626 	list_for_each_entry(pos2, &thermal_cdev_list, node) {
627 		if (pos2 == cdev)
628 			break;
629 	}
630 
631 	if (tz != pos1 || cdev != pos2)
632 		return -EINVAL;
633 
634 	/* lower default 0, upper default max_state */
635 	lower = lower == THERMAL_NO_LIMIT ? 0 : lower;
636 
637 	if (upper == THERMAL_NO_LIMIT) {
638 		upper = cdev->max_state;
639 		upper_no_limit = true;
640 	} else {
641 		upper_no_limit = false;
642 	}
643 
644 	if (lower > upper || upper > cdev->max_state)
645 		return -EINVAL;
646 
647 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
648 	if (!dev)
649 		return -ENOMEM;
650 	dev->tz = tz;
651 	dev->cdev = cdev;
652 	dev->trip = trip;
653 	dev->upper = upper;
654 	dev->upper_no_limit = upper_no_limit;
655 	dev->lower = lower;
656 	dev->target = THERMAL_NO_TARGET;
657 	dev->weight = weight;
658 
659 	result = ida_alloc(&tz->ida, GFP_KERNEL);
660 	if (result < 0)
661 		goto free_mem;
662 
663 	dev->id = result;
664 	sprintf(dev->name, "cdev%d", dev->id);
665 	result =
666 	    sysfs_create_link(&tz->device.kobj, &cdev->device.kobj, dev->name);
667 	if (result)
668 		goto release_ida;
669 
670 	sprintf(dev->attr_name, "cdev%d_trip_point", dev->id);
671 	sysfs_attr_init(&dev->attr.attr);
672 	dev->attr.attr.name = dev->attr_name;
673 	dev->attr.attr.mode = 0444;
674 	dev->attr.show = trip_point_show;
675 	result = device_create_file(&tz->device, &dev->attr);
676 	if (result)
677 		goto remove_symbol_link;
678 
679 	sprintf(dev->weight_attr_name, "cdev%d_weight", dev->id);
680 	sysfs_attr_init(&dev->weight_attr.attr);
681 	dev->weight_attr.attr.name = dev->weight_attr_name;
682 	dev->weight_attr.attr.mode = S_IWUSR | S_IRUGO;
683 	dev->weight_attr.show = weight_show;
684 	dev->weight_attr.store = weight_store;
685 	result = device_create_file(&tz->device, &dev->weight_attr);
686 	if (result)
687 		goto remove_trip_file;
688 
689 	mutex_lock(&tz->lock);
690 	mutex_lock(&cdev->lock);
691 	list_for_each_entry(pos, &tz->thermal_instances, tz_node)
692 		if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
693 			result = -EEXIST;
694 			break;
695 		}
696 	if (!result) {
697 		list_add_tail(&dev->tz_node, &tz->thermal_instances);
698 		list_add_tail(&dev->cdev_node, &cdev->thermal_instances);
699 		atomic_set(&tz->need_update, 1);
700 	}
701 	mutex_unlock(&cdev->lock);
702 	mutex_unlock(&tz->lock);
703 
704 	if (!result)
705 		return 0;
706 
707 	device_remove_file(&tz->device, &dev->weight_attr);
708 remove_trip_file:
709 	device_remove_file(&tz->device, &dev->attr);
710 remove_symbol_link:
711 	sysfs_remove_link(&tz->device.kobj, dev->name);
712 release_ida:
713 	ida_free(&tz->ida, dev->id);
714 free_mem:
715 	kfree(dev);
716 	return result;
717 }
718 EXPORT_SYMBOL_GPL(thermal_zone_bind_cooling_device);
719 
720 /**
721  * thermal_zone_unbind_cooling_device() - unbind a cooling device from a
722  *					  thermal zone.
723  * @tz:		pointer to a struct thermal_zone_device.
724  * @trip:	indicates which trip point the cooling devices is
725  *		associated with in this thermal zone.
726  * @cdev:	pointer to a struct thermal_cooling_device.
727  *
728  * This interface function unbind a thermal cooling device from the certain
729  * trip point of a thermal zone device.
730  * This function is usually called in the thermal zone device .unbind callback.
731  *
732  * Return: 0 on success, the proper error value otherwise.
733  */
734 int thermal_zone_unbind_cooling_device(struct thermal_zone_device *tz,
735 				       int trip,
736 				       struct thermal_cooling_device *cdev)
737 {
738 	struct thermal_instance *pos, *next;
739 
740 	mutex_lock(&tz->lock);
741 	mutex_lock(&cdev->lock);
742 	list_for_each_entry_safe(pos, next, &tz->thermal_instances, tz_node) {
743 		if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
744 			list_del(&pos->tz_node);
745 			list_del(&pos->cdev_node);
746 			mutex_unlock(&cdev->lock);
747 			mutex_unlock(&tz->lock);
748 			goto unbind;
749 		}
750 	}
751 	mutex_unlock(&cdev->lock);
752 	mutex_unlock(&tz->lock);
753 
754 	return -ENODEV;
755 
756 unbind:
757 	device_remove_file(&tz->device, &pos->weight_attr);
758 	device_remove_file(&tz->device, &pos->attr);
759 	sysfs_remove_link(&tz->device.kobj, pos->name);
760 	ida_free(&tz->ida, pos->id);
761 	kfree(pos);
762 	return 0;
763 }
764 EXPORT_SYMBOL_GPL(thermal_zone_unbind_cooling_device);
765 
766 static void thermal_release(struct device *dev)
767 {
768 	struct thermal_zone_device *tz;
769 	struct thermal_cooling_device *cdev;
770 
771 	if (!strncmp(dev_name(dev), "thermal_zone",
772 		     sizeof("thermal_zone") - 1)) {
773 		tz = to_thermal_zone(dev);
774 		thermal_zone_destroy_device_groups(tz);
775 		mutex_destroy(&tz->lock);
776 		kfree(tz);
777 	} else if (!strncmp(dev_name(dev), "cooling_device",
778 			    sizeof("cooling_device") - 1)) {
779 		cdev = to_cooling_device(dev);
780 		thermal_cooling_device_destroy_sysfs(cdev);
781 		kfree(cdev->type);
782 		ida_free(&thermal_cdev_ida, cdev->id);
783 		kfree(cdev);
784 	}
785 }
786 
787 static struct class *thermal_class;
788 
789 static inline
790 void print_bind_err_msg(struct thermal_zone_device *tz,
791 			struct thermal_cooling_device *cdev, int ret)
792 {
793 	dev_err(&tz->device, "binding zone %s with cdev %s failed:%d\n",
794 		tz->type, cdev->type, ret);
795 }
796 
797 static void __bind(struct thermal_zone_device *tz, int mask,
798 		   struct thermal_cooling_device *cdev,
799 		   unsigned long *limits,
800 		   unsigned int weight)
801 {
802 	int i, ret;
803 
804 	for (i = 0; i < tz->num_trips; i++) {
805 		if (mask & (1 << i)) {
806 			unsigned long upper, lower;
807 
808 			upper = THERMAL_NO_LIMIT;
809 			lower = THERMAL_NO_LIMIT;
810 			if (limits) {
811 				lower = limits[i * 2];
812 				upper = limits[i * 2 + 1];
813 			}
814 			ret = thermal_zone_bind_cooling_device(tz, i, cdev,
815 							       upper, lower,
816 							       weight);
817 			if (ret)
818 				print_bind_err_msg(tz, cdev, ret);
819 		}
820 	}
821 }
822 
823 static void bind_cdev(struct thermal_cooling_device *cdev)
824 {
825 	int i, ret;
826 	const struct thermal_zone_params *tzp;
827 	struct thermal_zone_device *pos = NULL;
828 
829 	mutex_lock(&thermal_list_lock);
830 
831 	list_for_each_entry(pos, &thermal_tz_list, node) {
832 		if (!pos->tzp && !pos->ops->bind)
833 			continue;
834 
835 		if (pos->ops->bind) {
836 			ret = pos->ops->bind(pos, cdev);
837 			if (ret)
838 				print_bind_err_msg(pos, cdev, ret);
839 			continue;
840 		}
841 
842 		tzp = pos->tzp;
843 		if (!tzp || !tzp->tbp)
844 			continue;
845 
846 		for (i = 0; i < tzp->num_tbps; i++) {
847 			if (tzp->tbp[i].cdev || !tzp->tbp[i].match)
848 				continue;
849 			if (tzp->tbp[i].match(pos, cdev))
850 				continue;
851 			tzp->tbp[i].cdev = cdev;
852 			__bind(pos, tzp->tbp[i].trip_mask, cdev,
853 			       tzp->tbp[i].binding_limits,
854 			       tzp->tbp[i].weight);
855 		}
856 	}
857 
858 	mutex_unlock(&thermal_list_lock);
859 }
860 
861 /**
862  * __thermal_cooling_device_register() - register a new thermal cooling device
863  * @np:		a pointer to a device tree node.
864  * @type:	the thermal cooling device type.
865  * @devdata:	device private data.
866  * @ops:		standard thermal cooling devices callbacks.
867  *
868  * This interface function adds a new thermal cooling device (fan/processor/...)
869  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
870  * to all the thermal zone devices registered at the same time.
871  * It also gives the opportunity to link the cooling device to a device tree
872  * node, so that it can be bound to a thermal zone created out of device tree.
873  *
874  * Return: a pointer to the created struct thermal_cooling_device or an
875  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
876  */
877 static struct thermal_cooling_device *
878 __thermal_cooling_device_register(struct device_node *np,
879 				  const char *type, void *devdata,
880 				  const struct thermal_cooling_device_ops *ops)
881 {
882 	struct thermal_cooling_device *cdev;
883 	struct thermal_zone_device *pos = NULL;
884 	int id, ret;
885 
886 	if (!ops || !ops->get_max_state || !ops->get_cur_state ||
887 	    !ops->set_cur_state)
888 		return ERR_PTR(-EINVAL);
889 
890 	if (!thermal_class)
891 		return ERR_PTR(-ENODEV);
892 
893 	cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
894 	if (!cdev)
895 		return ERR_PTR(-ENOMEM);
896 
897 	ret = ida_alloc(&thermal_cdev_ida, GFP_KERNEL);
898 	if (ret < 0)
899 		goto out_kfree_cdev;
900 	cdev->id = ret;
901 	id = ret;
902 
903 	cdev->type = kstrdup(type ? type : "", GFP_KERNEL);
904 	if (!cdev->type) {
905 		ret = -ENOMEM;
906 		goto out_ida_remove;
907 	}
908 
909 	mutex_init(&cdev->lock);
910 	INIT_LIST_HEAD(&cdev->thermal_instances);
911 	cdev->np = np;
912 	cdev->ops = ops;
913 	cdev->updated = false;
914 	cdev->device.class = thermal_class;
915 	cdev->devdata = devdata;
916 
917 	ret = cdev->ops->get_max_state(cdev, &cdev->max_state);
918 	if (ret)
919 		goto out_cdev_type;
920 
921 	thermal_cooling_device_setup_sysfs(cdev);
922 
923 	ret = dev_set_name(&cdev->device, "cooling_device%d", cdev->id);
924 	if (ret)
925 		goto out_cooling_dev;
926 
927 	ret = device_register(&cdev->device);
928 	if (ret) {
929 		/* thermal_release() handles rest of the cleanup */
930 		put_device(&cdev->device);
931 		return ERR_PTR(ret);
932 	}
933 
934 	/* Add 'this' new cdev to the global cdev list */
935 	mutex_lock(&thermal_list_lock);
936 	list_add(&cdev->node, &thermal_cdev_list);
937 	mutex_unlock(&thermal_list_lock);
938 
939 	/* Update binding information for 'this' new cdev */
940 	bind_cdev(cdev);
941 
942 	mutex_lock(&thermal_list_lock);
943 	list_for_each_entry(pos, &thermal_tz_list, node)
944 		if (atomic_cmpxchg(&pos->need_update, 1, 0))
945 			thermal_zone_device_update(pos,
946 						   THERMAL_EVENT_UNSPECIFIED);
947 	mutex_unlock(&thermal_list_lock);
948 
949 	return cdev;
950 
951 out_cooling_dev:
952 	thermal_cooling_device_destroy_sysfs(cdev);
953 out_cdev_type:
954 	kfree(cdev->type);
955 out_ida_remove:
956 	ida_free(&thermal_cdev_ida, id);
957 out_kfree_cdev:
958 	kfree(cdev);
959 	return ERR_PTR(ret);
960 }
961 
962 /**
963  * thermal_cooling_device_register() - register a new thermal cooling device
964  * @type:	the thermal cooling device type.
965  * @devdata:	device private data.
966  * @ops:		standard thermal cooling devices callbacks.
967  *
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_cooling_device_register(const char *type, void *devdata,
977 				const struct thermal_cooling_device_ops *ops)
978 {
979 	return __thermal_cooling_device_register(NULL, type, devdata, ops);
980 }
981 EXPORT_SYMBOL_GPL(thermal_cooling_device_register);
982 
983 /**
984  * thermal_of_cooling_device_register() - register an OF thermal cooling device
985  * @np:		a pointer to a device tree node.
986  * @type:	the thermal cooling device type.
987  * @devdata:	device private data.
988  * @ops:		standard thermal cooling devices callbacks.
989  *
990  * This function will register a cooling device with device tree node reference.
991  * This interface function adds a new thermal cooling device (fan/processor/...)
992  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
993  * to all the thermal zone devices registered at the same time.
994  *
995  * Return: a pointer to the created struct thermal_cooling_device or an
996  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
997  */
998 struct thermal_cooling_device *
999 thermal_of_cooling_device_register(struct device_node *np,
1000 				   const char *type, void *devdata,
1001 				   const struct thermal_cooling_device_ops *ops)
1002 {
1003 	return __thermal_cooling_device_register(np, type, devdata, ops);
1004 }
1005 EXPORT_SYMBOL_GPL(thermal_of_cooling_device_register);
1006 
1007 static void thermal_cooling_device_release(struct device *dev, void *res)
1008 {
1009 	thermal_cooling_device_unregister(
1010 				*(struct thermal_cooling_device **)res);
1011 }
1012 
1013 /**
1014  * devm_thermal_of_cooling_device_register() - register an OF thermal cooling
1015  *					       device
1016  * @dev:	a valid struct device pointer of a sensor device.
1017  * @np:		a pointer to a device tree node.
1018  * @type:	the thermal cooling device type.
1019  * @devdata:	device private data.
1020  * @ops:	standard thermal cooling devices callbacks.
1021  *
1022  * This function will register a cooling device with device tree node reference.
1023  * This interface function adds a new thermal cooling device (fan/processor/...)
1024  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
1025  * to all the thermal zone devices registered at the same time.
1026  *
1027  * Return: a pointer to the created struct thermal_cooling_device or an
1028  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
1029  */
1030 struct thermal_cooling_device *
1031 devm_thermal_of_cooling_device_register(struct device *dev,
1032 				struct device_node *np,
1033 				char *type, void *devdata,
1034 				const struct thermal_cooling_device_ops *ops)
1035 {
1036 	struct thermal_cooling_device **ptr, *tcd;
1037 
1038 	ptr = devres_alloc(thermal_cooling_device_release, sizeof(*ptr),
1039 			   GFP_KERNEL);
1040 	if (!ptr)
1041 		return ERR_PTR(-ENOMEM);
1042 
1043 	tcd = __thermal_cooling_device_register(np, type, devdata, ops);
1044 	if (IS_ERR(tcd)) {
1045 		devres_free(ptr);
1046 		return tcd;
1047 	}
1048 
1049 	*ptr = tcd;
1050 	devres_add(dev, ptr);
1051 
1052 	return tcd;
1053 }
1054 EXPORT_SYMBOL_GPL(devm_thermal_of_cooling_device_register);
1055 
1056 static bool thermal_cooling_device_present(struct thermal_cooling_device *cdev)
1057 {
1058 	struct thermal_cooling_device *pos = NULL;
1059 
1060 	list_for_each_entry(pos, &thermal_cdev_list, node) {
1061 		if (pos == cdev)
1062 			return true;
1063 	}
1064 
1065 	return false;
1066 }
1067 
1068 /**
1069  * thermal_cooling_device_update - Update a cooling device object
1070  * @cdev: Target cooling device.
1071  *
1072  * Update @cdev to reflect a change of the underlying hardware or platform.
1073  *
1074  * Must be called when the maximum cooling state of @cdev becomes invalid and so
1075  * its .get_max_state() callback needs to be run to produce the new maximum
1076  * cooling state value.
1077  */
1078 void thermal_cooling_device_update(struct thermal_cooling_device *cdev)
1079 {
1080 	struct thermal_instance *ti;
1081 	unsigned long state;
1082 
1083 	if (IS_ERR_OR_NULL(cdev))
1084 		return;
1085 
1086 	/*
1087 	 * Hold thermal_list_lock throughout the update to prevent the device
1088 	 * from going away while being updated.
1089 	 */
1090 	mutex_lock(&thermal_list_lock);
1091 
1092 	if (!thermal_cooling_device_present(cdev))
1093 		goto unlock_list;
1094 
1095 	/*
1096 	 * Update under the cdev lock to prevent the state from being set beyond
1097 	 * the new limit concurrently.
1098 	 */
1099 	mutex_lock(&cdev->lock);
1100 
1101 	if (cdev->ops->get_max_state(cdev, &cdev->max_state))
1102 		goto unlock;
1103 
1104 	thermal_cooling_device_stats_reinit(cdev);
1105 
1106 	list_for_each_entry(ti, &cdev->thermal_instances, cdev_node) {
1107 		if (ti->upper == cdev->max_state)
1108 			continue;
1109 
1110 		if (ti->upper < cdev->max_state) {
1111 			if (ti->upper_no_limit)
1112 				ti->upper = cdev->max_state;
1113 
1114 			continue;
1115 		}
1116 
1117 		ti->upper = cdev->max_state;
1118 		if (ti->lower > ti->upper)
1119 			ti->lower = ti->upper;
1120 
1121 		if (ti->target == THERMAL_NO_TARGET)
1122 			continue;
1123 
1124 		if (ti->target > ti->upper)
1125 			ti->target = ti->upper;
1126 	}
1127 
1128 	if (cdev->ops->get_cur_state(cdev, &state) || state > cdev->max_state)
1129 		goto unlock;
1130 
1131 	thermal_cooling_device_stats_update(cdev, state);
1132 
1133 unlock:
1134 	mutex_unlock(&cdev->lock);
1135 
1136 unlock_list:
1137 	mutex_unlock(&thermal_list_lock);
1138 }
1139 EXPORT_SYMBOL_GPL(thermal_cooling_device_update);
1140 
1141 static void __unbind(struct thermal_zone_device *tz, int mask,
1142 		     struct thermal_cooling_device *cdev)
1143 {
1144 	int i;
1145 
1146 	for (i = 0; i < tz->num_trips; i++)
1147 		if (mask & (1 << i))
1148 			thermal_zone_unbind_cooling_device(tz, i, cdev);
1149 }
1150 
1151 /**
1152  * thermal_cooling_device_unregister - removes a thermal cooling device
1153  * @cdev:	the thermal cooling device to remove.
1154  *
1155  * thermal_cooling_device_unregister() must be called when a registered
1156  * thermal cooling device is no longer needed.
1157  */
1158 void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev)
1159 {
1160 	int i;
1161 	const struct thermal_zone_params *tzp;
1162 	struct thermal_zone_device *tz;
1163 
1164 	if (!cdev)
1165 		return;
1166 
1167 	mutex_lock(&thermal_list_lock);
1168 
1169 	if (!thermal_cooling_device_present(cdev)) {
1170 		mutex_unlock(&thermal_list_lock);
1171 		return;
1172 	}
1173 
1174 	list_del(&cdev->node);
1175 
1176 	/* Unbind all thermal zones associated with 'this' cdev */
1177 	list_for_each_entry(tz, &thermal_tz_list, node) {
1178 		if (tz->ops->unbind) {
1179 			tz->ops->unbind(tz, cdev);
1180 			continue;
1181 		}
1182 
1183 		if (!tz->tzp || !tz->tzp->tbp)
1184 			continue;
1185 
1186 		tzp = tz->tzp;
1187 		for (i = 0; i < tzp->num_tbps; i++) {
1188 			if (tzp->tbp[i].cdev == cdev) {
1189 				__unbind(tz, tzp->tbp[i].trip_mask, cdev);
1190 				tzp->tbp[i].cdev = NULL;
1191 			}
1192 		}
1193 	}
1194 
1195 	mutex_unlock(&thermal_list_lock);
1196 
1197 	device_unregister(&cdev->device);
1198 }
1199 EXPORT_SYMBOL_GPL(thermal_cooling_device_unregister);
1200 
1201 static void bind_tz(struct thermal_zone_device *tz)
1202 {
1203 	int i, ret;
1204 	struct thermal_cooling_device *pos = NULL;
1205 	const struct thermal_zone_params *tzp = tz->tzp;
1206 
1207 	if (!tzp && !tz->ops->bind)
1208 		return;
1209 
1210 	mutex_lock(&thermal_list_lock);
1211 
1212 	/* If there is ops->bind, try to use ops->bind */
1213 	if (tz->ops->bind) {
1214 		list_for_each_entry(pos, &thermal_cdev_list, node) {
1215 			ret = tz->ops->bind(tz, pos);
1216 			if (ret)
1217 				print_bind_err_msg(tz, pos, ret);
1218 		}
1219 		goto exit;
1220 	}
1221 
1222 	if (!tzp || !tzp->tbp)
1223 		goto exit;
1224 
1225 	list_for_each_entry(pos, &thermal_cdev_list, node) {
1226 		for (i = 0; i < tzp->num_tbps; i++) {
1227 			if (tzp->tbp[i].cdev || !tzp->tbp[i].match)
1228 				continue;
1229 			if (tzp->tbp[i].match(tz, pos))
1230 				continue;
1231 			tzp->tbp[i].cdev = pos;
1232 			__bind(tz, tzp->tbp[i].trip_mask, pos,
1233 			       tzp->tbp[i].binding_limits,
1234 			       tzp->tbp[i].weight);
1235 		}
1236 	}
1237 exit:
1238 	mutex_unlock(&thermal_list_lock);
1239 }
1240 
1241 static void thermal_set_delay_jiffies(unsigned long *delay_jiffies, int delay_ms)
1242 {
1243 	*delay_jiffies = msecs_to_jiffies(delay_ms);
1244 	if (delay_ms > 1000)
1245 		*delay_jiffies = round_jiffies(*delay_jiffies);
1246 }
1247 
1248 int thermal_zone_get_crit_temp(struct thermal_zone_device *tz, int *temp)
1249 {
1250 	int i, ret = -EINVAL;
1251 
1252 	if (tz->ops->get_crit_temp)
1253 		return tz->ops->get_crit_temp(tz, temp);
1254 
1255 	if (!tz->trips)
1256 		return -EINVAL;
1257 
1258 	mutex_lock(&tz->lock);
1259 
1260 	for (i = 0; i < tz->num_trips; i++) {
1261 		if (tz->trips[i].type == THERMAL_TRIP_CRITICAL) {
1262 			*temp = tz->trips[i].temperature;
1263 			ret = 0;
1264 			break;
1265 		}
1266 	}
1267 
1268 	mutex_unlock(&tz->lock);
1269 
1270 	return ret;
1271 }
1272 EXPORT_SYMBOL_GPL(thermal_zone_get_crit_temp);
1273 
1274 /**
1275  * thermal_zone_device_register_with_trips() - register a new thermal zone device
1276  * @type:	the thermal zone device type
1277  * @trips:	a pointer to an array of thermal trips
1278  * @num_trips:	the number of trip points the thermal zone support
1279  * @mask:	a bit string indicating the writeablility of trip points
1280  * @devdata:	private device data
1281  * @ops:	standard thermal zone device callbacks
1282  * @tzp:	thermal zone platform parameters
1283  * @passive_delay: number of milliseconds to wait between polls when
1284  *		   performing passive cooling
1285  * @polling_delay: number of milliseconds to wait between polls when checking
1286  *		   whether trip points have been crossed (0 for interrupt
1287  *		   driven systems)
1288  *
1289  * This interface function adds a new thermal zone device (sensor) to
1290  * /sys/class/thermal folder as thermal_zone[0-*]. It tries to bind all the
1291  * thermal cooling devices registered at the same time.
1292  * thermal_zone_device_unregister() must be called when the device is no
1293  * longer needed. The passive cooling depends on the .get_trend() return value.
1294  *
1295  * Return: a pointer to the created struct thermal_zone_device or an
1296  * in case of error, an ERR_PTR. Caller must check return value with
1297  * IS_ERR*() helpers.
1298  */
1299 struct thermal_zone_device *
1300 thermal_zone_device_register_with_trips(const char *type, struct thermal_trip *trips, int num_trips, int mask,
1301 					void *devdata, struct thermal_zone_device_ops *ops,
1302 					struct thermal_zone_params *tzp, int passive_delay,
1303 					int polling_delay)
1304 {
1305 	struct thermal_zone_device *tz;
1306 	int id;
1307 	int result;
1308 	int count;
1309 	struct thermal_governor *governor;
1310 
1311 	if (!type || strlen(type) == 0) {
1312 		pr_err("No thermal zone type defined\n");
1313 		return ERR_PTR(-EINVAL);
1314 	}
1315 
1316 	if (strlen(type) >= THERMAL_NAME_LENGTH) {
1317 		pr_err("Thermal zone name (%s) too long, should be under %d chars\n",
1318 		       type, THERMAL_NAME_LENGTH);
1319 		return ERR_PTR(-EINVAL);
1320 	}
1321 
1322 	/*
1323 	 * Max trip count can't exceed 31 as the "mask >> num_trips" condition.
1324 	 * For example, shifting by 32 will result in compiler warning:
1325 	 * warning: right shift count >= width of type [-Wshift-count- overflow]
1326 	 *
1327 	 * Also "mask >> num_trips" will always be true with 32 bit shift.
1328 	 * E.g. mask = 0x80000000 for trip id 31 to be RW. Then
1329 	 * mask >> 32 = 0x80000000
1330 	 * This will result in failure for the below condition.
1331 	 *
1332 	 * Check will be true when the bit 31 of the mask is set.
1333 	 * 32 bit shift will cause overflow of 4 byte integer.
1334 	 */
1335 	if (num_trips > (BITS_PER_TYPE(int) - 1) || num_trips < 0 || mask >> num_trips) {
1336 		pr_err("Incorrect number of thermal trips\n");
1337 		return ERR_PTR(-EINVAL);
1338 	}
1339 
1340 	if (!ops) {
1341 		pr_err("Thermal zone device ops not defined\n");
1342 		return ERR_PTR(-EINVAL);
1343 	}
1344 
1345 	if (num_trips > 0 && (!ops->get_trip_type || !ops->get_trip_temp) && !trips)
1346 		return ERR_PTR(-EINVAL);
1347 
1348 	if (!thermal_class)
1349 		return ERR_PTR(-ENODEV);
1350 
1351 	tz = kzalloc(sizeof(*tz), GFP_KERNEL);
1352 	if (!tz)
1353 		return ERR_PTR(-ENOMEM);
1354 
1355 	INIT_LIST_HEAD(&tz->thermal_instances);
1356 	ida_init(&tz->ida);
1357 	mutex_init(&tz->lock);
1358 	id = ida_alloc(&thermal_tz_ida, GFP_KERNEL);
1359 	if (id < 0) {
1360 		result = id;
1361 		goto free_tz;
1362 	}
1363 
1364 	tz->id = id;
1365 	strscpy(tz->type, type, sizeof(tz->type));
1366 
1367 	if (!ops->critical)
1368 		ops->critical = thermal_zone_device_critical;
1369 
1370 	tz->ops = ops;
1371 	tz->tzp = tzp;
1372 	tz->device.class = thermal_class;
1373 	tz->devdata = devdata;
1374 	tz->trips = trips;
1375 	tz->num_trips = num_trips;
1376 
1377 	thermal_set_delay_jiffies(&tz->passive_delay_jiffies, passive_delay);
1378 	thermal_set_delay_jiffies(&tz->polling_delay_jiffies, polling_delay);
1379 
1380 	/* sys I/F */
1381 	/* Add nodes that are always present via .groups */
1382 	result = thermal_zone_create_device_groups(tz, mask);
1383 	if (result)
1384 		goto remove_id;
1385 
1386 	/* A new thermal zone needs to be updated anyway. */
1387 	atomic_set(&tz->need_update, 1);
1388 
1389 	result = dev_set_name(&tz->device, "thermal_zone%d", tz->id);
1390 	if (result) {
1391 		thermal_zone_destroy_device_groups(tz);
1392 		goto remove_id;
1393 	}
1394 	result = device_register(&tz->device);
1395 	if (result)
1396 		goto release_device;
1397 
1398 	for (count = 0; count < num_trips; count++) {
1399 		struct thermal_trip trip;
1400 
1401 		result = thermal_zone_get_trip(tz, count, &trip);
1402 		if (result || !trip.temperature)
1403 			set_bit(count, &tz->trips_disabled);
1404 	}
1405 
1406 	/* Update 'this' zone's governor information */
1407 	mutex_lock(&thermal_governor_lock);
1408 
1409 	if (tz->tzp)
1410 		governor = __find_governor(tz->tzp->governor_name);
1411 	else
1412 		governor = def_governor;
1413 
1414 	result = thermal_set_governor(tz, governor);
1415 	if (result) {
1416 		mutex_unlock(&thermal_governor_lock);
1417 		goto unregister;
1418 	}
1419 
1420 	mutex_unlock(&thermal_governor_lock);
1421 
1422 	if (!tz->tzp || !tz->tzp->no_hwmon) {
1423 		result = thermal_add_hwmon_sysfs(tz);
1424 		if (result)
1425 			goto unregister;
1426 	}
1427 
1428 	mutex_lock(&thermal_list_lock);
1429 	list_add_tail(&tz->node, &thermal_tz_list);
1430 	mutex_unlock(&thermal_list_lock);
1431 
1432 	/* Bind cooling devices for this zone */
1433 	bind_tz(tz);
1434 
1435 	INIT_DELAYED_WORK(&tz->poll_queue, thermal_zone_device_check);
1436 
1437 	thermal_zone_device_init(tz);
1438 	/* Update the new thermal zone and mark it as already updated. */
1439 	if (atomic_cmpxchg(&tz->need_update, 1, 0))
1440 		thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
1441 
1442 	thermal_notify_tz_create(tz->id, tz->type);
1443 
1444 	return tz;
1445 
1446 unregister:
1447 	device_del(&tz->device);
1448 release_device:
1449 	put_device(&tz->device);
1450 	tz = NULL;
1451 remove_id:
1452 	ida_free(&thermal_tz_ida, id);
1453 free_tz:
1454 	kfree(tz);
1455 	return ERR_PTR(result);
1456 }
1457 EXPORT_SYMBOL_GPL(thermal_zone_device_register_with_trips);
1458 
1459 struct thermal_zone_device *thermal_zone_device_register(const char *type, int ntrips, int mask,
1460 							 void *devdata, struct thermal_zone_device_ops *ops,
1461 							 struct thermal_zone_params *tzp, int passive_delay,
1462 							 int polling_delay)
1463 {
1464 	return thermal_zone_device_register_with_trips(type, NULL, ntrips, mask,
1465 						       devdata, ops, tzp,
1466 						       passive_delay, polling_delay);
1467 }
1468 EXPORT_SYMBOL_GPL(thermal_zone_device_register);
1469 
1470 /**
1471  * thermal_zone_device_unregister - removes the registered thermal zone device
1472  * @tz: the thermal zone device to remove
1473  */
1474 void thermal_zone_device_unregister(struct thermal_zone_device *tz)
1475 {
1476 	int i, tz_id;
1477 	const struct thermal_zone_params *tzp;
1478 	struct thermal_cooling_device *cdev;
1479 	struct thermal_zone_device *pos = NULL;
1480 
1481 	if (!tz)
1482 		return;
1483 
1484 	tzp = tz->tzp;
1485 	tz_id = tz->id;
1486 
1487 	mutex_lock(&thermal_list_lock);
1488 	list_for_each_entry(pos, &thermal_tz_list, node)
1489 		if (pos == tz)
1490 			break;
1491 	if (pos != tz) {
1492 		/* thermal zone device not found */
1493 		mutex_unlock(&thermal_list_lock);
1494 		return;
1495 	}
1496 	list_del(&tz->node);
1497 
1498 	/* Unbind all cdevs associated with 'this' thermal zone */
1499 	list_for_each_entry(cdev, &thermal_cdev_list, node) {
1500 		if (tz->ops->unbind) {
1501 			tz->ops->unbind(tz, cdev);
1502 			continue;
1503 		}
1504 
1505 		if (!tzp || !tzp->tbp)
1506 			break;
1507 
1508 		for (i = 0; i < tzp->num_tbps; i++) {
1509 			if (tzp->tbp[i].cdev == cdev) {
1510 				__unbind(tz, tzp->tbp[i].trip_mask, cdev);
1511 				tzp->tbp[i].cdev = NULL;
1512 			}
1513 		}
1514 	}
1515 
1516 	mutex_unlock(&thermal_list_lock);
1517 
1518 	cancel_delayed_work_sync(&tz->poll_queue);
1519 
1520 	thermal_set_governor(tz, NULL);
1521 
1522 	thermal_remove_hwmon_sysfs(tz);
1523 	ida_free(&thermal_tz_ida, tz->id);
1524 	ida_destroy(&tz->ida);
1525 
1526 	mutex_lock(&tz->lock);
1527 	device_del(&tz->device);
1528 	mutex_unlock(&tz->lock);
1529 
1530 	put_device(&tz->device);
1531 
1532 	thermal_notify_tz_delete(tz_id);
1533 }
1534 EXPORT_SYMBOL_GPL(thermal_zone_device_unregister);
1535 
1536 /**
1537  * thermal_zone_get_zone_by_name() - search for a zone and returns its ref
1538  * @name: thermal zone name to fetch the temperature
1539  *
1540  * When only one zone is found with the passed name, returns a reference to it.
1541  *
1542  * Return: On success returns a reference to an unique thermal zone with
1543  * matching name equals to @name, an ERR_PTR otherwise (-EINVAL for invalid
1544  * paramenters, -ENODEV for not found and -EEXIST for multiple matches).
1545  */
1546 struct thermal_zone_device *thermal_zone_get_zone_by_name(const char *name)
1547 {
1548 	struct thermal_zone_device *pos = NULL, *ref = ERR_PTR(-EINVAL);
1549 	unsigned int found = 0;
1550 
1551 	if (!name)
1552 		goto exit;
1553 
1554 	mutex_lock(&thermal_list_lock);
1555 	list_for_each_entry(pos, &thermal_tz_list, node)
1556 		if (!strncasecmp(name, pos->type, THERMAL_NAME_LENGTH)) {
1557 			found++;
1558 			ref = pos;
1559 		}
1560 	mutex_unlock(&thermal_list_lock);
1561 
1562 	/* nothing has been found, thus an error code for it */
1563 	if (found == 0)
1564 		ref = ERR_PTR(-ENODEV);
1565 	else if (found > 1)
1566 	/* Success only when an unique zone is found */
1567 		ref = ERR_PTR(-EEXIST);
1568 
1569 exit:
1570 	return ref;
1571 }
1572 EXPORT_SYMBOL_GPL(thermal_zone_get_zone_by_name);
1573 
1574 static int thermal_pm_notify(struct notifier_block *nb,
1575 			     unsigned long mode, void *_unused)
1576 {
1577 	struct thermal_zone_device *tz;
1578 
1579 	switch (mode) {
1580 	case PM_HIBERNATION_PREPARE:
1581 	case PM_RESTORE_PREPARE:
1582 	case PM_SUSPEND_PREPARE:
1583 		atomic_set(&in_suspend, 1);
1584 		break;
1585 	case PM_POST_HIBERNATION:
1586 	case PM_POST_RESTORE:
1587 	case PM_POST_SUSPEND:
1588 		atomic_set(&in_suspend, 0);
1589 		list_for_each_entry(tz, &thermal_tz_list, node) {
1590 			thermal_zone_device_init(tz);
1591 			thermal_zone_device_update(tz,
1592 						   THERMAL_EVENT_UNSPECIFIED);
1593 		}
1594 		break;
1595 	default:
1596 		break;
1597 	}
1598 	return 0;
1599 }
1600 
1601 static struct notifier_block thermal_pm_nb = {
1602 	.notifier_call = thermal_pm_notify,
1603 };
1604 
1605 static int __init thermal_init(void)
1606 {
1607 	int result;
1608 
1609 	result = thermal_netlink_init();
1610 	if (result)
1611 		goto error;
1612 
1613 	result = thermal_register_governors();
1614 	if (result)
1615 		goto unregister_netlink;
1616 
1617 	thermal_class = kzalloc(sizeof(*thermal_class), GFP_KERNEL);
1618 	if (!thermal_class) {
1619 		result = -ENOMEM;
1620 		goto unregister_governors;
1621 	}
1622 
1623 	thermal_class->name = "thermal";
1624 	thermal_class->dev_release = thermal_release;
1625 
1626 	result = class_register(thermal_class);
1627 	if (result) {
1628 		kfree(thermal_class);
1629 		thermal_class = NULL;
1630 		goto unregister_governors;
1631 	}
1632 
1633 	result = register_pm_notifier(&thermal_pm_nb);
1634 	if (result)
1635 		pr_warn("Thermal: Can not register suspend notifier, return %d\n",
1636 			result);
1637 
1638 	return 0;
1639 
1640 unregister_governors:
1641 	thermal_unregister_governors();
1642 unregister_netlink:
1643 	thermal_netlink_exit();
1644 error:
1645 	mutex_destroy(&thermal_list_lock);
1646 	mutex_destroy(&thermal_governor_lock);
1647 	return result;
1648 }
1649 postcore_initcall(thermal_init);
1650