GNU Linux-libre 5.19-rc6-gnu
[releases.git] / drivers / thermal / thermal_core.c
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         gov = __find_governor(strim(policy));
207         if (!gov)
208                 goto exit;
209
210         ret = thermal_set_governor(tz, gov);
211
212 exit:
213         mutex_unlock(&tz->lock);
214         mutex_unlock(&thermal_governor_lock);
215
216         thermal_notify_tz_gov_change(tz->id, policy);
217
218         return ret;
219 }
220
221 int thermal_build_list_of_policies(char *buf)
222 {
223         struct thermal_governor *pos;
224         ssize_t count = 0;
225
226         mutex_lock(&thermal_governor_lock);
227
228         list_for_each_entry(pos, &thermal_governor_list, governor_list) {
229                 count += scnprintf(buf + count, PAGE_SIZE - count, "%s ",
230                                    pos->name);
231         }
232         count += scnprintf(buf + count, PAGE_SIZE - 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 inline bool should_stop_polling(struct thermal_zone_device *tz)
299 {
300         return !thermal_zone_device_is_enabled(tz);
301 }
302
303 static void monitor_thermal_zone(struct thermal_zone_device *tz)
304 {
305         bool stop;
306
307         stop = should_stop_polling(tz);
308
309         mutex_lock(&tz->lock);
310
311         if (!stop && tz->passive)
312                 thermal_zone_device_set_polling(tz, tz->passive_delay_jiffies);
313         else if (!stop && tz->polling_delay_jiffies)
314                 thermal_zone_device_set_polling(tz, tz->polling_delay_jiffies);
315         else
316                 thermal_zone_device_set_polling(tz, 0);
317
318         mutex_unlock(&tz->lock);
319 }
320
321 static void handle_non_critical_trips(struct thermal_zone_device *tz, int trip)
322 {
323         tz->governor ? tz->governor->throttle(tz, trip) :
324                        def_governor->throttle(tz, trip);
325 }
326
327 void thermal_zone_device_critical(struct thermal_zone_device *tz)
328 {
329         /*
330          * poweroff_delay_ms must be a carefully profiled positive value.
331          * Its a must for forced_emergency_poweroff_work to be scheduled.
332          */
333         int poweroff_delay_ms = CONFIG_THERMAL_EMERGENCY_POWEROFF_DELAY_MS;
334
335         dev_emerg(&tz->device, "%s: critical temperature reached, "
336                   "shutting down\n", tz->type);
337
338         hw_protection_shutdown("Temperature too high", poweroff_delay_ms);
339 }
340 EXPORT_SYMBOL(thermal_zone_device_critical);
341
342 static void handle_critical_trips(struct thermal_zone_device *tz,
343                                   int trip, enum thermal_trip_type trip_type)
344 {
345         int trip_temp;
346
347         tz->ops->get_trip_temp(tz, trip, &trip_temp);
348
349         /* If we have not crossed the trip_temp, we do not care. */
350         if (trip_temp <= 0 || tz->temperature < trip_temp)
351                 return;
352
353         trace_thermal_zone_trip(tz, trip, trip_type);
354
355         if (trip_type == THERMAL_TRIP_HOT && tz->ops->hot)
356                 tz->ops->hot(tz);
357         else if (trip_type == THERMAL_TRIP_CRITICAL)
358                 tz->ops->critical(tz);
359 }
360
361 static void handle_thermal_trip(struct thermal_zone_device *tz, int trip)
362 {
363         enum thermal_trip_type type;
364         int trip_temp, hyst = 0;
365
366         /* Ignore disabled trip points */
367         if (test_bit(trip, &tz->trips_disabled))
368                 return;
369
370         tz->ops->get_trip_temp(tz, trip, &trip_temp);
371         tz->ops->get_trip_type(tz, trip, &type);
372         if (tz->ops->get_trip_hyst)
373                 tz->ops->get_trip_hyst(tz, trip, &hyst);
374
375         if (tz->last_temperature != THERMAL_TEMP_INVALID) {
376                 if (tz->last_temperature < trip_temp &&
377                     tz->temperature >= trip_temp)
378                         thermal_notify_tz_trip_up(tz->id, trip,
379                                                   tz->temperature);
380                 if (tz->last_temperature >= trip_temp &&
381                     tz->temperature < (trip_temp - hyst))
382                         thermal_notify_tz_trip_down(tz->id, trip,
383                                                     tz->temperature);
384         }
385
386         if (type == THERMAL_TRIP_CRITICAL || type == THERMAL_TRIP_HOT)
387                 handle_critical_trips(tz, trip, type);
388         else
389                 handle_non_critical_trips(tz, trip);
390         /*
391          * Alright, we handled this trip successfully.
392          * So, start monitoring again.
393          */
394         monitor_thermal_zone(tz);
395 }
396
397 static void update_temperature(struct thermal_zone_device *tz)
398 {
399         int temp, ret;
400
401         ret = thermal_zone_get_temp(tz, &temp);
402         if (ret) {
403                 if (ret != -EAGAIN)
404                         dev_warn(&tz->device,
405                                  "failed to read out thermal zone (%d)\n",
406                                  ret);
407                 return;
408         }
409
410         mutex_lock(&tz->lock);
411         tz->last_temperature = tz->temperature;
412         tz->temperature = temp;
413         mutex_unlock(&tz->lock);
414
415         trace_thermal_temperature(tz);
416
417         thermal_genl_sampling_temp(tz->id, temp);
418 }
419
420 static void thermal_zone_device_init(struct thermal_zone_device *tz)
421 {
422         struct thermal_instance *pos;
423         tz->temperature = THERMAL_TEMP_INVALID;
424         tz->prev_low_trip = -INT_MAX;
425         tz->prev_high_trip = INT_MAX;
426         list_for_each_entry(pos, &tz->thermal_instances, tz_node)
427                 pos->initialized = false;
428 }
429
430 static int thermal_zone_device_set_mode(struct thermal_zone_device *tz,
431                                         enum thermal_device_mode mode)
432 {
433         int ret = 0;
434
435         mutex_lock(&tz->lock);
436
437         /* do nothing if mode isn't changing */
438         if (mode == tz->mode) {
439                 mutex_unlock(&tz->lock);
440
441                 return ret;
442         }
443
444         if (tz->ops->change_mode)
445                 ret = tz->ops->change_mode(tz, mode);
446
447         if (!ret)
448                 tz->mode = mode;
449
450         mutex_unlock(&tz->lock);
451
452         thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
453
454         if (mode == THERMAL_DEVICE_ENABLED)
455                 thermal_notify_tz_enable(tz->id);
456         else
457                 thermal_notify_tz_disable(tz->id);
458
459         return ret;
460 }
461
462 int thermal_zone_device_enable(struct thermal_zone_device *tz)
463 {
464         return thermal_zone_device_set_mode(tz, THERMAL_DEVICE_ENABLED);
465 }
466 EXPORT_SYMBOL_GPL(thermal_zone_device_enable);
467
468 int thermal_zone_device_disable(struct thermal_zone_device *tz)
469 {
470         return thermal_zone_device_set_mode(tz, THERMAL_DEVICE_DISABLED);
471 }
472 EXPORT_SYMBOL_GPL(thermal_zone_device_disable);
473
474 int thermal_zone_device_is_enabled(struct thermal_zone_device *tz)
475 {
476         enum thermal_device_mode mode;
477
478         mutex_lock(&tz->lock);
479
480         mode = tz->mode;
481
482         mutex_unlock(&tz->lock);
483
484         return mode == THERMAL_DEVICE_ENABLED;
485 }
486
487 void thermal_zone_device_update(struct thermal_zone_device *tz,
488                                 enum thermal_notify_event event)
489 {
490         int count;
491
492         if (should_stop_polling(tz))
493                 return;
494
495         if (atomic_read(&in_suspend))
496                 return;
497
498         if (WARN_ONCE(!tz->ops->get_temp, "'%s' must not be called without "
499                       "'get_temp' ops set\n", __func__))
500                 return;
501
502         update_temperature(tz);
503
504         thermal_zone_set_trips(tz);
505
506         tz->notify_event = event;
507
508         for (count = 0; count < tz->trips; count++)
509                 handle_thermal_trip(tz, count);
510 }
511 EXPORT_SYMBOL_GPL(thermal_zone_device_update);
512
513 static void thermal_zone_device_check(struct work_struct *work)
514 {
515         struct thermal_zone_device *tz = container_of(work, struct
516                                                       thermal_zone_device,
517                                                       poll_queue.work);
518         thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
519 }
520
521 int for_each_thermal_governor(int (*cb)(struct thermal_governor *, void *),
522                               void *data)
523 {
524         struct thermal_governor *gov;
525         int ret = 0;
526
527         mutex_lock(&thermal_governor_lock);
528         list_for_each_entry(gov, &thermal_governor_list, governor_list) {
529                 ret = cb(gov, data);
530                 if (ret)
531                         break;
532         }
533         mutex_unlock(&thermal_governor_lock);
534
535         return ret;
536 }
537
538 int for_each_thermal_cooling_device(int (*cb)(struct thermal_cooling_device *,
539                                               void *), void *data)
540 {
541         struct thermal_cooling_device *cdev;
542         int ret = 0;
543
544         mutex_lock(&thermal_list_lock);
545         list_for_each_entry(cdev, &thermal_cdev_list, node) {
546                 ret = cb(cdev, data);
547                 if (ret)
548                         break;
549         }
550         mutex_unlock(&thermal_list_lock);
551
552         return ret;
553 }
554
555 int for_each_thermal_zone(int (*cb)(struct thermal_zone_device *, void *),
556                           void *data)
557 {
558         struct thermal_zone_device *tz;
559         int ret = 0;
560
561         mutex_lock(&thermal_list_lock);
562         list_for_each_entry(tz, &thermal_tz_list, node) {
563                 ret = cb(tz, data);
564                 if (ret)
565                         break;
566         }
567         mutex_unlock(&thermal_list_lock);
568
569         return ret;
570 }
571
572 struct thermal_zone_device *thermal_zone_get_by_id(int id)
573 {
574         struct thermal_zone_device *tz, *match = NULL;
575
576         mutex_lock(&thermal_list_lock);
577         list_for_each_entry(tz, &thermal_tz_list, node) {
578                 if (tz->id == id) {
579                         match = tz;
580                         break;
581                 }
582         }
583         mutex_unlock(&thermal_list_lock);
584
585         return match;
586 }
587
588 /*
589  * Device management section: cooling devices, zones devices, and binding
590  *
591  * Set of functions provided by the thermal core for:
592  * - cooling devices lifecycle: registration, unregistration,
593  *                              binding, and unbinding.
594  * - thermal zone devices lifecycle: registration, unregistration,
595  *                                   binding, and unbinding.
596  */
597
598 /**
599  * thermal_zone_bind_cooling_device() - bind a cooling device to a thermal zone
600  * @tz:         pointer to struct thermal_zone_device
601  * @trip:       indicates which trip point the cooling devices is
602  *              associated with in this thermal zone.
603  * @cdev:       pointer to struct thermal_cooling_device
604  * @upper:      the Maximum cooling state for this trip point.
605  *              THERMAL_NO_LIMIT means no upper limit,
606  *              and the cooling device can be in max_state.
607  * @lower:      the Minimum cooling state can be used for this trip point.
608  *              THERMAL_NO_LIMIT means no lower limit,
609  *              and the cooling device can be in cooling state 0.
610  * @weight:     The weight of the cooling device to be bound to the
611  *              thermal zone. Use THERMAL_WEIGHT_DEFAULT for the
612  *              default value
613  *
614  * This interface function bind a thermal cooling device to the certain trip
615  * point of a thermal zone device.
616  * This function is usually called in the thermal zone device .bind callback.
617  *
618  * Return: 0 on success, the proper error value otherwise.
619  */
620 int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz,
621                                      int trip,
622                                      struct thermal_cooling_device *cdev,
623                                      unsigned long upper, unsigned long lower,
624                                      unsigned int weight)
625 {
626         struct thermal_instance *dev;
627         struct thermal_instance *pos;
628         struct thermal_zone_device *pos1;
629         struct thermal_cooling_device *pos2;
630         unsigned long max_state;
631         int result, ret;
632
633         if (trip >= tz->trips || trip < 0)
634                 return -EINVAL;
635
636         list_for_each_entry(pos1, &thermal_tz_list, node) {
637                 if (pos1 == tz)
638                         break;
639         }
640         list_for_each_entry(pos2, &thermal_cdev_list, node) {
641                 if (pos2 == cdev)
642                         break;
643         }
644
645         if (tz != pos1 || cdev != pos2)
646                 return -EINVAL;
647
648         ret = cdev->ops->get_max_state(cdev, &max_state);
649         if (ret)
650                 return ret;
651
652         /* lower default 0, upper default max_state */
653         lower = lower == THERMAL_NO_LIMIT ? 0 : lower;
654         upper = upper == THERMAL_NO_LIMIT ? max_state : upper;
655
656         if (lower > upper || upper > max_state)
657                 return -EINVAL;
658
659         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
660         if (!dev)
661                 return -ENOMEM;
662         dev->tz = tz;
663         dev->cdev = cdev;
664         dev->trip = trip;
665         dev->upper = upper;
666         dev->lower = lower;
667         dev->target = THERMAL_NO_TARGET;
668         dev->weight = weight;
669
670         result = ida_simple_get(&tz->ida, 0, 0, GFP_KERNEL);
671         if (result < 0)
672                 goto free_mem;
673
674         dev->id = result;
675         sprintf(dev->name, "cdev%d", dev->id);
676         result =
677             sysfs_create_link(&tz->device.kobj, &cdev->device.kobj, dev->name);
678         if (result)
679                 goto release_ida;
680
681         sprintf(dev->attr_name, "cdev%d_trip_point", dev->id);
682         sysfs_attr_init(&dev->attr.attr);
683         dev->attr.attr.name = dev->attr_name;
684         dev->attr.attr.mode = 0444;
685         dev->attr.show = trip_point_show;
686         result = device_create_file(&tz->device, &dev->attr);
687         if (result)
688                 goto remove_symbol_link;
689
690         sprintf(dev->weight_attr_name, "cdev%d_weight", dev->id);
691         sysfs_attr_init(&dev->weight_attr.attr);
692         dev->weight_attr.attr.name = dev->weight_attr_name;
693         dev->weight_attr.attr.mode = S_IWUSR | S_IRUGO;
694         dev->weight_attr.show = weight_show;
695         dev->weight_attr.store = weight_store;
696         result = device_create_file(&tz->device, &dev->weight_attr);
697         if (result)
698                 goto remove_trip_file;
699
700         mutex_lock(&tz->lock);
701         mutex_lock(&cdev->lock);
702         list_for_each_entry(pos, &tz->thermal_instances, tz_node)
703                 if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
704                         result = -EEXIST;
705                         break;
706                 }
707         if (!result) {
708                 list_add_tail(&dev->tz_node, &tz->thermal_instances);
709                 list_add_tail(&dev->cdev_node, &cdev->thermal_instances);
710                 atomic_set(&tz->need_update, 1);
711         }
712         mutex_unlock(&cdev->lock);
713         mutex_unlock(&tz->lock);
714
715         if (!result)
716                 return 0;
717
718         device_remove_file(&tz->device, &dev->weight_attr);
719 remove_trip_file:
720         device_remove_file(&tz->device, &dev->attr);
721 remove_symbol_link:
722         sysfs_remove_link(&tz->device.kobj, dev->name);
723 release_ida:
724         ida_simple_remove(&tz->ida, dev->id);
725 free_mem:
726         kfree(dev);
727         return result;
728 }
729 EXPORT_SYMBOL_GPL(thermal_zone_bind_cooling_device);
730
731 /**
732  * thermal_zone_unbind_cooling_device() - unbind a cooling device from a
733  *                                        thermal zone.
734  * @tz:         pointer to a struct thermal_zone_device.
735  * @trip:       indicates which trip point the cooling devices is
736  *              associated with in this thermal zone.
737  * @cdev:       pointer to a struct thermal_cooling_device.
738  *
739  * This interface function unbind a thermal cooling device from the certain
740  * trip point of a thermal zone device.
741  * This function is usually called in the thermal zone device .unbind callback.
742  *
743  * Return: 0 on success, the proper error value otherwise.
744  */
745 int thermal_zone_unbind_cooling_device(struct thermal_zone_device *tz,
746                                        int trip,
747                                        struct thermal_cooling_device *cdev)
748 {
749         struct thermal_instance *pos, *next;
750
751         mutex_lock(&tz->lock);
752         mutex_lock(&cdev->lock);
753         list_for_each_entry_safe(pos, next, &tz->thermal_instances, tz_node) {
754                 if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
755                         list_del(&pos->tz_node);
756                         list_del(&pos->cdev_node);
757                         mutex_unlock(&cdev->lock);
758                         mutex_unlock(&tz->lock);
759                         goto unbind;
760                 }
761         }
762         mutex_unlock(&cdev->lock);
763         mutex_unlock(&tz->lock);
764
765         return -ENODEV;
766
767 unbind:
768         device_remove_file(&tz->device, &pos->weight_attr);
769         device_remove_file(&tz->device, &pos->attr);
770         sysfs_remove_link(&tz->device.kobj, pos->name);
771         ida_simple_remove(&tz->ida, pos->id);
772         kfree(pos);
773         return 0;
774 }
775 EXPORT_SYMBOL_GPL(thermal_zone_unbind_cooling_device);
776
777 static void thermal_release(struct device *dev)
778 {
779         struct thermal_zone_device *tz;
780         struct thermal_cooling_device *cdev;
781
782         if (!strncmp(dev_name(dev), "thermal_zone",
783                      sizeof("thermal_zone") - 1)) {
784                 tz = to_thermal_zone(dev);
785                 thermal_zone_destroy_device_groups(tz);
786                 kfree(tz);
787         } else if (!strncmp(dev_name(dev), "cooling_device",
788                             sizeof("cooling_device") - 1)) {
789                 cdev = to_cooling_device(dev);
790                 kfree(cdev);
791         }
792 }
793
794 static struct class thermal_class = {
795         .name = "thermal",
796         .dev_release = thermal_release,
797 };
798
799 static inline
800 void print_bind_err_msg(struct thermal_zone_device *tz,
801                         struct thermal_cooling_device *cdev, int ret)
802 {
803         dev_err(&tz->device, "binding zone %s with cdev %s failed:%d\n",
804                 tz->type, cdev->type, ret);
805 }
806
807 static void __bind(struct thermal_zone_device *tz, int mask,
808                    struct thermal_cooling_device *cdev,
809                    unsigned long *limits,
810                    unsigned int weight)
811 {
812         int i, ret;
813
814         for (i = 0; i < tz->trips; i++) {
815                 if (mask & (1 << i)) {
816                         unsigned long upper, lower;
817
818                         upper = THERMAL_NO_LIMIT;
819                         lower = THERMAL_NO_LIMIT;
820                         if (limits) {
821                                 lower = limits[i * 2];
822                                 upper = limits[i * 2 + 1];
823                         }
824                         ret = thermal_zone_bind_cooling_device(tz, i, cdev,
825                                                                upper, lower,
826                                                                weight);
827                         if (ret)
828                                 print_bind_err_msg(tz, cdev, ret);
829                 }
830         }
831 }
832
833 static void bind_cdev(struct thermal_cooling_device *cdev)
834 {
835         int i, ret;
836         const struct thermal_zone_params *tzp;
837         struct thermal_zone_device *pos = NULL;
838
839         mutex_lock(&thermal_list_lock);
840
841         list_for_each_entry(pos, &thermal_tz_list, node) {
842                 if (!pos->tzp && !pos->ops->bind)
843                         continue;
844
845                 if (pos->ops->bind) {
846                         ret = pos->ops->bind(pos, cdev);
847                         if (ret)
848                                 print_bind_err_msg(pos, cdev, ret);
849                         continue;
850                 }
851
852                 tzp = pos->tzp;
853                 if (!tzp || !tzp->tbp)
854                         continue;
855
856                 for (i = 0; i < tzp->num_tbps; i++) {
857                         if (tzp->tbp[i].cdev || !tzp->tbp[i].match)
858                                 continue;
859                         if (tzp->tbp[i].match(pos, cdev))
860                                 continue;
861                         tzp->tbp[i].cdev = cdev;
862                         __bind(pos, tzp->tbp[i].trip_mask, cdev,
863                                tzp->tbp[i].binding_limits,
864                                tzp->tbp[i].weight);
865                 }
866         }
867
868         mutex_unlock(&thermal_list_lock);
869 }
870
871 /**
872  * __thermal_cooling_device_register() - register a new thermal cooling device
873  * @np:         a pointer to a device tree node.
874  * @type:       the thermal cooling device type.
875  * @devdata:    device private data.
876  * @ops:                standard thermal cooling devices callbacks.
877  *
878  * This interface function adds a new thermal cooling device (fan/processor/...)
879  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
880  * to all the thermal zone devices registered at the same time.
881  * It also gives the opportunity to link the cooling device to a device tree
882  * node, so that it can be bound to a thermal zone created out of device tree.
883  *
884  * Return: a pointer to the created struct thermal_cooling_device or an
885  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
886  */
887 static struct thermal_cooling_device *
888 __thermal_cooling_device_register(struct device_node *np,
889                                   const char *type, void *devdata,
890                                   const struct thermal_cooling_device_ops *ops)
891 {
892         struct thermal_cooling_device *cdev;
893         struct thermal_zone_device *pos = NULL;
894         int id, ret;
895
896         if (!ops || !ops->get_max_state || !ops->get_cur_state ||
897             !ops->set_cur_state)
898                 return ERR_PTR(-EINVAL);
899
900         cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
901         if (!cdev)
902                 return ERR_PTR(-ENOMEM);
903
904         ret = ida_simple_get(&thermal_cdev_ida, 0, 0, GFP_KERNEL);
905         if (ret < 0)
906                 goto out_kfree_cdev;
907         cdev->id = ret;
908         id = ret;
909
910         ret = dev_set_name(&cdev->device, "cooling_device%d", cdev->id);
911         if (ret)
912                 goto out_ida_remove;
913
914         cdev->type = kstrdup(type ? type : "", GFP_KERNEL);
915         if (!cdev->type) {
916                 ret = -ENOMEM;
917                 goto out_ida_remove;
918         }
919
920         mutex_init(&cdev->lock);
921         INIT_LIST_HEAD(&cdev->thermal_instances);
922         cdev->np = np;
923         cdev->ops = ops;
924         cdev->updated = false;
925         cdev->device.class = &thermal_class;
926         cdev->devdata = devdata;
927         thermal_cooling_device_setup_sysfs(cdev);
928         ret = device_register(&cdev->device);
929         if (ret)
930                 goto out_kfree_type;
931
932         /* Add 'this' new cdev to the global cdev list */
933         mutex_lock(&thermal_list_lock);
934         list_add(&cdev->node, &thermal_cdev_list);
935         mutex_unlock(&thermal_list_lock);
936
937         /* Update binding information for 'this' new cdev */
938         bind_cdev(cdev);
939
940         mutex_lock(&thermal_list_lock);
941         list_for_each_entry(pos, &thermal_tz_list, node)
942                 if (atomic_cmpxchg(&pos->need_update, 1, 0))
943                         thermal_zone_device_update(pos,
944                                                    THERMAL_EVENT_UNSPECIFIED);
945         mutex_unlock(&thermal_list_lock);
946
947         return cdev;
948
949 out_kfree_type:
950         thermal_cooling_device_destroy_sysfs(cdev);
951         kfree(cdev->type);
952         put_device(&cdev->device);
953         cdev = NULL;
954 out_ida_remove:
955         ida_simple_remove(&thermal_cdev_ida, id);
956 out_kfree_cdev:
957         kfree(cdev);
958         return ERR_PTR(ret);
959 }
960
961 /**
962  * thermal_cooling_device_register() - register a new thermal cooling device
963  * @type:       the thermal cooling device type.
964  * @devdata:    device private data.
965  * @ops:                standard thermal cooling devices callbacks.
966  *
967  * This interface function adds a new thermal cooling device (fan/processor/...)
968  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
969  * to all the thermal zone devices registered at the same time.
970  *
971  * Return: a pointer to the created struct thermal_cooling_device or an
972  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
973  */
974 struct thermal_cooling_device *
975 thermal_cooling_device_register(const char *type, void *devdata,
976                                 const struct thermal_cooling_device_ops *ops)
977 {
978         return __thermal_cooling_device_register(NULL, type, devdata, ops);
979 }
980 EXPORT_SYMBOL_GPL(thermal_cooling_device_register);
981
982 /**
983  * thermal_of_cooling_device_register() - register an OF thermal cooling device
984  * @np:         a pointer to a device tree node.
985  * @type:       the thermal cooling device type.
986  * @devdata:    device private data.
987  * @ops:                standard thermal cooling devices callbacks.
988  *
989  * This function will register a cooling device with device tree node reference.
990  * This interface function adds a new thermal cooling device (fan/processor/...)
991  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
992  * to all the thermal zone devices registered at the same time.
993  *
994  * Return: a pointer to the created struct thermal_cooling_device or an
995  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
996  */
997 struct thermal_cooling_device *
998 thermal_of_cooling_device_register(struct device_node *np,
999                                    const char *type, void *devdata,
1000                                    const struct thermal_cooling_device_ops *ops)
1001 {
1002         return __thermal_cooling_device_register(np, type, devdata, ops);
1003 }
1004 EXPORT_SYMBOL_GPL(thermal_of_cooling_device_register);
1005
1006 static void thermal_cooling_device_release(struct device *dev, void *res)
1007 {
1008         thermal_cooling_device_unregister(
1009                                 *(struct thermal_cooling_device **)res);
1010 }
1011
1012 /**
1013  * devm_thermal_of_cooling_device_register() - register an OF thermal cooling
1014  *                                             device
1015  * @dev:        a valid struct device pointer of a sensor device.
1016  * @np:         a pointer to a device tree node.
1017  * @type:       the thermal cooling device type.
1018  * @devdata:    device private data.
1019  * @ops:        standard thermal cooling devices callbacks.
1020  *
1021  * This function will register a cooling device with device tree node reference.
1022  * This interface function adds a new thermal cooling device (fan/processor/...)
1023  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
1024  * to all the thermal zone devices registered at the same time.
1025  *
1026  * Return: a pointer to the created struct thermal_cooling_device or an
1027  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
1028  */
1029 struct thermal_cooling_device *
1030 devm_thermal_of_cooling_device_register(struct device *dev,
1031                                 struct device_node *np,
1032                                 char *type, void *devdata,
1033                                 const struct thermal_cooling_device_ops *ops)
1034 {
1035         struct thermal_cooling_device **ptr, *tcd;
1036
1037         ptr = devres_alloc(thermal_cooling_device_release, sizeof(*ptr),
1038                            GFP_KERNEL);
1039         if (!ptr)
1040                 return ERR_PTR(-ENOMEM);
1041
1042         tcd = __thermal_cooling_device_register(np, type, devdata, ops);
1043         if (IS_ERR(tcd)) {
1044                 devres_free(ptr);
1045                 return tcd;
1046         }
1047
1048         *ptr = tcd;
1049         devres_add(dev, ptr);
1050
1051         return tcd;
1052 }
1053 EXPORT_SYMBOL_GPL(devm_thermal_of_cooling_device_register);
1054
1055 static void __unbind(struct thermal_zone_device *tz, int mask,
1056                      struct thermal_cooling_device *cdev)
1057 {
1058         int i;
1059
1060         for (i = 0; i < tz->trips; i++)
1061                 if (mask & (1 << i))
1062                         thermal_zone_unbind_cooling_device(tz, i, cdev);
1063 }
1064
1065 /**
1066  * thermal_cooling_device_unregister - removes a thermal cooling device
1067  * @cdev:       the thermal cooling device to remove.
1068  *
1069  * thermal_cooling_device_unregister() must be called when a registered
1070  * thermal cooling device is no longer needed.
1071  */
1072 void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev)
1073 {
1074         int i;
1075         const struct thermal_zone_params *tzp;
1076         struct thermal_zone_device *tz;
1077         struct thermal_cooling_device *pos = NULL;
1078
1079         if (!cdev)
1080                 return;
1081
1082         mutex_lock(&thermal_list_lock);
1083         list_for_each_entry(pos, &thermal_cdev_list, node)
1084                 if (pos == cdev)
1085                         break;
1086         if (pos != cdev) {
1087                 /* thermal cooling device not found */
1088                 mutex_unlock(&thermal_list_lock);
1089                 return;
1090         }
1091         list_del(&cdev->node);
1092
1093         /* Unbind all thermal zones associated with 'this' cdev */
1094         list_for_each_entry(tz, &thermal_tz_list, node) {
1095                 if (tz->ops->unbind) {
1096                         tz->ops->unbind(tz, cdev);
1097                         continue;
1098                 }
1099
1100                 if (!tz->tzp || !tz->tzp->tbp)
1101                         continue;
1102
1103                 tzp = tz->tzp;
1104                 for (i = 0; i < tzp->num_tbps; i++) {
1105                         if (tzp->tbp[i].cdev == cdev) {
1106                                 __unbind(tz, tzp->tbp[i].trip_mask, cdev);
1107                                 tzp->tbp[i].cdev = NULL;
1108                         }
1109                 }
1110         }
1111
1112         mutex_unlock(&thermal_list_lock);
1113
1114         ida_simple_remove(&thermal_cdev_ida, cdev->id);
1115         device_del(&cdev->device);
1116         thermal_cooling_device_destroy_sysfs(cdev);
1117         kfree(cdev->type);
1118         put_device(&cdev->device);
1119 }
1120 EXPORT_SYMBOL_GPL(thermal_cooling_device_unregister);
1121
1122 static void bind_tz(struct thermal_zone_device *tz)
1123 {
1124         int i, ret;
1125         struct thermal_cooling_device *pos = NULL;
1126         const struct thermal_zone_params *tzp = tz->tzp;
1127
1128         if (!tzp && !tz->ops->bind)
1129                 return;
1130
1131         mutex_lock(&thermal_list_lock);
1132
1133         /* If there is ops->bind, try to use ops->bind */
1134         if (tz->ops->bind) {
1135                 list_for_each_entry(pos, &thermal_cdev_list, node) {
1136                         ret = tz->ops->bind(tz, pos);
1137                         if (ret)
1138                                 print_bind_err_msg(tz, pos, ret);
1139                 }
1140                 goto exit;
1141         }
1142
1143         if (!tzp || !tzp->tbp)
1144                 goto exit;
1145
1146         list_for_each_entry(pos, &thermal_cdev_list, node) {
1147                 for (i = 0; i < tzp->num_tbps; i++) {
1148                         if (tzp->tbp[i].cdev || !tzp->tbp[i].match)
1149                                 continue;
1150                         if (tzp->tbp[i].match(tz, pos))
1151                                 continue;
1152                         tzp->tbp[i].cdev = pos;
1153                         __bind(tz, tzp->tbp[i].trip_mask, pos,
1154                                tzp->tbp[i].binding_limits,
1155                                tzp->tbp[i].weight);
1156                 }
1157         }
1158 exit:
1159         mutex_unlock(&thermal_list_lock);
1160 }
1161
1162 /**
1163  * thermal_zone_device_register() - register a new thermal zone device
1164  * @type:       the thermal zone device type
1165  * @trips:      the number of trip points the thermal zone support
1166  * @mask:       a bit string indicating the writeablility of trip points
1167  * @devdata:    private device data
1168  * @ops:        standard thermal zone device callbacks
1169  * @tzp:        thermal zone platform parameters
1170  * @passive_delay: number of milliseconds to wait between polls when
1171  *                 performing passive cooling
1172  * @polling_delay: number of milliseconds to wait between polls when checking
1173  *                 whether trip points have been crossed (0 for interrupt
1174  *                 driven systems)
1175  *
1176  * This interface function adds a new thermal zone device (sensor) to
1177  * /sys/class/thermal folder as thermal_zone[0-*]. It tries to bind all the
1178  * thermal cooling devices registered at the same time.
1179  * thermal_zone_device_unregister() must be called when the device is no
1180  * longer needed. The passive cooling depends on the .get_trend() return value.
1181  *
1182  * Return: a pointer to the created struct thermal_zone_device or an
1183  * in case of error, an ERR_PTR. Caller must check return value with
1184  * IS_ERR*() helpers.
1185  */
1186 struct thermal_zone_device *
1187 thermal_zone_device_register(const char *type, int trips, int mask,
1188                              void *devdata, struct thermal_zone_device_ops *ops,
1189                              struct thermal_zone_params *tzp, int passive_delay,
1190                              int polling_delay)
1191 {
1192         struct thermal_zone_device *tz;
1193         enum thermal_trip_type trip_type;
1194         int trip_temp;
1195         int id;
1196         int result;
1197         int count;
1198         struct thermal_governor *governor;
1199
1200         if (!type || strlen(type) == 0) {
1201                 pr_err("Error: No thermal zone type defined\n");
1202                 return ERR_PTR(-EINVAL);
1203         }
1204
1205         if (type && strlen(type) >= THERMAL_NAME_LENGTH) {
1206                 pr_err("Error: Thermal zone name (%s) too long, should be under %d chars\n",
1207                        type, THERMAL_NAME_LENGTH);
1208                 return ERR_PTR(-EINVAL);
1209         }
1210
1211         if (trips > THERMAL_MAX_TRIPS || trips < 0 || mask >> trips) {
1212                 pr_err("Error: Incorrect number of thermal trips\n");
1213                 return ERR_PTR(-EINVAL);
1214         }
1215
1216         if (!ops) {
1217                 pr_err("Error: Thermal zone device ops not defined\n");
1218                 return ERR_PTR(-EINVAL);
1219         }
1220
1221         if (trips > 0 && (!ops->get_trip_type || !ops->get_trip_temp))
1222                 return ERR_PTR(-EINVAL);
1223
1224         tz = kzalloc(sizeof(*tz), GFP_KERNEL);
1225         if (!tz)
1226                 return ERR_PTR(-ENOMEM);
1227
1228         INIT_LIST_HEAD(&tz->thermal_instances);
1229         ida_init(&tz->ida);
1230         mutex_init(&tz->lock);
1231         id = ida_simple_get(&thermal_tz_ida, 0, 0, GFP_KERNEL);
1232         if (id < 0) {
1233                 result = id;
1234                 goto free_tz;
1235         }
1236
1237         tz->id = id;
1238         strlcpy(tz->type, type, sizeof(tz->type));
1239
1240         result = dev_set_name(&tz->device, "thermal_zone%d", tz->id);
1241         if (result)
1242                 goto remove_id;
1243
1244         if (!ops->critical)
1245                 ops->critical = thermal_zone_device_critical;
1246
1247         tz->ops = ops;
1248         tz->tzp = tzp;
1249         tz->device.class = &thermal_class;
1250         tz->devdata = devdata;
1251         tz->trips = trips;
1252
1253         thermal_set_delay_jiffies(&tz->passive_delay_jiffies, passive_delay);
1254         thermal_set_delay_jiffies(&tz->polling_delay_jiffies, polling_delay);
1255
1256         /* sys I/F */
1257         /* Add nodes that are always present via .groups */
1258         result = thermal_zone_create_device_groups(tz, mask);
1259         if (result)
1260                 goto remove_id;
1261
1262         /* A new thermal zone needs to be updated anyway. */
1263         atomic_set(&tz->need_update, 1);
1264
1265         result = device_register(&tz->device);
1266         if (result)
1267                 goto release_device;
1268
1269         for (count = 0; count < trips; count++) {
1270                 if (tz->ops->get_trip_type(tz, count, &trip_type) ||
1271                     tz->ops->get_trip_temp(tz, count, &trip_temp) ||
1272                     !trip_temp)
1273                         set_bit(count, &tz->trips_disabled);
1274         }
1275
1276         /* Update 'this' zone's governor information */
1277         mutex_lock(&thermal_governor_lock);
1278
1279         if (tz->tzp)
1280                 governor = __find_governor(tz->tzp->governor_name);
1281         else
1282                 governor = def_governor;
1283
1284         result = thermal_set_governor(tz, governor);
1285         if (result) {
1286                 mutex_unlock(&thermal_governor_lock);
1287                 goto unregister;
1288         }
1289
1290         mutex_unlock(&thermal_governor_lock);
1291
1292         if (!tz->tzp || !tz->tzp->no_hwmon) {
1293                 result = thermal_add_hwmon_sysfs(tz);
1294                 if (result)
1295                         goto unregister;
1296         }
1297
1298         mutex_lock(&thermal_list_lock);
1299         list_add_tail(&tz->node, &thermal_tz_list);
1300         mutex_unlock(&thermal_list_lock);
1301
1302         /* Bind cooling devices for this zone */
1303         bind_tz(tz);
1304
1305         INIT_DELAYED_WORK(&tz->poll_queue, thermal_zone_device_check);
1306
1307         thermal_zone_device_init(tz);
1308         /* Update the new thermal zone and mark it as already updated. */
1309         if (atomic_cmpxchg(&tz->need_update, 1, 0))
1310                 thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
1311
1312         thermal_notify_tz_create(tz->id, tz->type);
1313
1314         return tz;
1315
1316 unregister:
1317         device_del(&tz->device);
1318 release_device:
1319         put_device(&tz->device);
1320         tz = NULL;
1321 remove_id:
1322         ida_simple_remove(&thermal_tz_ida, id);
1323 free_tz:
1324         kfree(tz);
1325         return ERR_PTR(result);
1326 }
1327 EXPORT_SYMBOL_GPL(thermal_zone_device_register);
1328
1329 /**
1330  * thermal_zone_device_unregister - removes the registered thermal zone device
1331  * @tz: the thermal zone device to remove
1332  */
1333 void thermal_zone_device_unregister(struct thermal_zone_device *tz)
1334 {
1335         int i, tz_id;
1336         const struct thermal_zone_params *tzp;
1337         struct thermal_cooling_device *cdev;
1338         struct thermal_zone_device *pos = NULL;
1339
1340         if (!tz)
1341                 return;
1342
1343         tzp = tz->tzp;
1344         tz_id = tz->id;
1345
1346         mutex_lock(&thermal_list_lock);
1347         list_for_each_entry(pos, &thermal_tz_list, node)
1348                 if (pos == tz)
1349                         break;
1350         if (pos != tz) {
1351                 /* thermal zone device not found */
1352                 mutex_unlock(&thermal_list_lock);
1353                 return;
1354         }
1355         list_del(&tz->node);
1356
1357         /* Unbind all cdevs associated with 'this' thermal zone */
1358         list_for_each_entry(cdev, &thermal_cdev_list, node) {
1359                 if (tz->ops->unbind) {
1360                         tz->ops->unbind(tz, cdev);
1361                         continue;
1362                 }
1363
1364                 if (!tzp || !tzp->tbp)
1365                         break;
1366
1367                 for (i = 0; i < tzp->num_tbps; i++) {
1368                         if (tzp->tbp[i].cdev == cdev) {
1369                                 __unbind(tz, tzp->tbp[i].trip_mask, cdev);
1370                                 tzp->tbp[i].cdev = NULL;
1371                         }
1372                 }
1373         }
1374
1375         mutex_unlock(&thermal_list_lock);
1376
1377         cancel_delayed_work_sync(&tz->poll_queue);
1378
1379         thermal_set_governor(tz, NULL);
1380
1381         thermal_remove_hwmon_sysfs(tz);
1382         ida_simple_remove(&thermal_tz_ida, tz->id);
1383         ida_destroy(&tz->ida);
1384         mutex_destroy(&tz->lock);
1385         device_unregister(&tz->device);
1386
1387         thermal_notify_tz_delete(tz_id);
1388 }
1389 EXPORT_SYMBOL_GPL(thermal_zone_device_unregister);
1390
1391 /**
1392  * thermal_zone_get_zone_by_name() - search for a zone and returns its ref
1393  * @name: thermal zone name to fetch the temperature
1394  *
1395  * When only one zone is found with the passed name, returns a reference to it.
1396  *
1397  * Return: On success returns a reference to an unique thermal zone with
1398  * matching name equals to @name, an ERR_PTR otherwise (-EINVAL for invalid
1399  * paramenters, -ENODEV for not found and -EEXIST for multiple matches).
1400  */
1401 struct thermal_zone_device *thermal_zone_get_zone_by_name(const char *name)
1402 {
1403         struct thermal_zone_device *pos = NULL, *ref = ERR_PTR(-EINVAL);
1404         unsigned int found = 0;
1405
1406         if (!name)
1407                 goto exit;
1408
1409         mutex_lock(&thermal_list_lock);
1410         list_for_each_entry(pos, &thermal_tz_list, node)
1411                 if (!strncasecmp(name, pos->type, THERMAL_NAME_LENGTH)) {
1412                         found++;
1413                         ref = pos;
1414                 }
1415         mutex_unlock(&thermal_list_lock);
1416
1417         /* nothing has been found, thus an error code for it */
1418         if (found == 0)
1419                 ref = ERR_PTR(-ENODEV);
1420         else if (found > 1)
1421         /* Success only when an unique zone is found */
1422                 ref = ERR_PTR(-EEXIST);
1423
1424 exit:
1425         return ref;
1426 }
1427 EXPORT_SYMBOL_GPL(thermal_zone_get_zone_by_name);
1428
1429 static int thermal_pm_notify(struct notifier_block *nb,
1430                              unsigned long mode, void *_unused)
1431 {
1432         struct thermal_zone_device *tz;
1433
1434         switch (mode) {
1435         case PM_HIBERNATION_PREPARE:
1436         case PM_RESTORE_PREPARE:
1437         case PM_SUSPEND_PREPARE:
1438                 atomic_set(&in_suspend, 1);
1439                 break;
1440         case PM_POST_HIBERNATION:
1441         case PM_POST_RESTORE:
1442         case PM_POST_SUSPEND:
1443                 atomic_set(&in_suspend, 0);
1444                 list_for_each_entry(tz, &thermal_tz_list, node) {
1445                         if (!thermal_zone_device_is_enabled(tz))
1446                                 continue;
1447
1448                         thermal_zone_device_init(tz);
1449                         thermal_zone_device_update(tz,
1450                                                    THERMAL_EVENT_UNSPECIFIED);
1451                 }
1452                 break;
1453         default:
1454                 break;
1455         }
1456         return 0;
1457 }
1458
1459 static struct notifier_block thermal_pm_nb = {
1460         .notifier_call = thermal_pm_notify,
1461 };
1462
1463 static int __init thermal_init(void)
1464 {
1465         int result;
1466
1467         result = thermal_netlink_init();
1468         if (result)
1469                 goto error;
1470
1471         result = thermal_register_governors();
1472         if (result)
1473                 goto error;
1474
1475         result = class_register(&thermal_class);
1476         if (result)
1477                 goto unregister_governors;
1478
1479         result = of_parse_thermal_zones();
1480         if (result)
1481                 goto unregister_class;
1482
1483         result = register_pm_notifier(&thermal_pm_nb);
1484         if (result)
1485                 pr_warn("Thermal: Can not register suspend notifier, return %d\n",
1486                         result);
1487
1488         return 0;
1489
1490 unregister_class:
1491         class_unregister(&thermal_class);
1492 unregister_governors:
1493         thermal_unregister_governors();
1494 error:
1495         ida_destroy(&thermal_tz_ida);
1496         ida_destroy(&thermal_cdev_ida);
1497         mutex_destroy(&thermal_list_lock);
1498         mutex_destroy(&thermal_governor_lock);
1499         return result;
1500 }
1501 postcore_initcall(thermal_init);