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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
30static DEFINE_IDA(thermal_tz_ida);
31static DEFINE_IDA(thermal_cdev_ida);
32
33static LIST_HEAD(thermal_tz_list);
34static LIST_HEAD(thermal_cdev_list);
35static LIST_HEAD(thermal_governor_list);
36
37static DEFINE_MUTEX(thermal_list_lock);
38static DEFINE_MUTEX(thermal_governor_lock);
39
40static atomic_t in_suspend;
41
42static 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
51static 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 */
73static 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 */
95static 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
117int 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
171void 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);
193exit:
194 mutex_unlock(&thermal_governor_lock);
195}
196
197int 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
215exit:
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
224int 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 += scnprintf(buf + count, PAGE_SIZE - count, "%s ",
233 pos->name);
234 }
235 count += scnprintf(buf + count, PAGE_SIZE - count, "\n");
236
237 mutex_unlock(&thermal_governor_lock);
238
239 return count;
240}
241
242static void __init thermal_unregister_governors(void)
243{
244 struct thermal_governor **governor;
245
246 for_each_governor_table(governor)
247 thermal_unregister_governor(*governor);
248}
249
250static int __init thermal_register_governors(void)
251{
252 int ret = 0;
253 struct thermal_governor **governor;
254
255 for_each_governor_table(governor) {
256 ret = thermal_register_governor(*governor);
257 if (ret) {
258 pr_err("Failed to register governor: '%s'",
259 (*governor)->name);
260 break;
261 }
262
263 pr_info("Registered thermal governor '%s'",
264 (*governor)->name);
265 }
266
267 if (ret) {
268 struct thermal_governor **gov;
269
270 for_each_governor_table(gov) {
271 if (gov == governor)
272 break;
273 thermal_unregister_governor(*gov);
274 }
275 }
276
277 return ret;
278}
279
280/*
281 * Zone update section: main control loop applied to each zone while monitoring
282 *
283 * in polling mode. The monitoring is done using a workqueue.
284 * Same update may be done on a zone by calling thermal_zone_device_update().
285 *
286 * An update means:
287 * - Non-critical trips will invoke the governor responsible for that zone;
288 * - Hot trips will produce a notification to userspace;
289 * - Critical trip point will cause a system shutdown.
290 */
291static void thermal_zone_device_set_polling(struct thermal_zone_device *tz,
292 unsigned long delay)
293{
294 if (delay)
295 mod_delayed_work(system_freezable_power_efficient_wq,
296 &tz->poll_queue, delay);
297 else
298 cancel_delayed_work(&tz->poll_queue);
299}
300
301static void monitor_thermal_zone(struct thermal_zone_device *tz)
302{
303 if (tz->mode != THERMAL_DEVICE_ENABLED)
304 thermal_zone_device_set_polling(tz, 0);
305 else if (tz->passive)
306 thermal_zone_device_set_polling(tz, tz->passive_delay_jiffies);
307 else if (tz->polling_delay_jiffies)
308 thermal_zone_device_set_polling(tz, tz->polling_delay_jiffies);
309}
310
311static void handle_non_critical_trips(struct thermal_zone_device *tz, int trip)
312{
313 tz->governor ? tz->governor->throttle(tz, trip) :
314 def_governor->throttle(tz, trip);
315}
316
317void thermal_zone_device_critical(struct thermal_zone_device *tz)
318{
319 /*
320 * poweroff_delay_ms must be a carefully profiled positive value.
321 * Its a must for forced_emergency_poweroff_work to be scheduled.
322 */
323 int poweroff_delay_ms = CONFIG_THERMAL_EMERGENCY_POWEROFF_DELAY_MS;
324
325 dev_emerg(&tz->device, "%s: critical temperature reached, "
326 "shutting down\n", tz->type);
327
328 hw_protection_shutdown("Temperature too high", poweroff_delay_ms);
329}
330EXPORT_SYMBOL(thermal_zone_device_critical);
331
332static void handle_critical_trips(struct thermal_zone_device *tz,
333 int trip, int trip_temp, enum thermal_trip_type trip_type)
334{
335 /* If we have not crossed the trip_temp, we do not care. */
336 if (trip_temp <= 0 || tz->temperature < trip_temp)
337 return;
338
339 trace_thermal_zone_trip(tz, trip, trip_type);
340
341 if (trip_type == THERMAL_TRIP_HOT && tz->ops->hot)
342 tz->ops->hot(tz);
343 else if (trip_type == THERMAL_TRIP_CRITICAL)
344 tz->ops->critical(tz);
345}
346
347static void handle_thermal_trip(struct thermal_zone_device *tz, int trip)
348{
349 enum thermal_trip_type type;
350 int trip_temp, hyst = 0;
351
352 /* Ignore disabled trip points */
353 if (test_bit(trip, &tz->trips_disabled))
354 return;
355
356 tz->ops->get_trip_temp(tz, trip, &trip_temp);
357 tz->ops->get_trip_type(tz, trip, &type);
358 if (tz->ops->get_trip_hyst)
359 tz->ops->get_trip_hyst(tz, trip, &hyst);
360
361 if (tz->last_temperature != THERMAL_TEMP_INVALID) {
362 if (tz->last_temperature < trip_temp &&
363 tz->temperature >= trip_temp)
364 thermal_notify_tz_trip_up(tz->id, trip,
365 tz->temperature);
366 if (tz->last_temperature >= trip_temp &&
367 tz->temperature < (trip_temp - hyst))
368 thermal_notify_tz_trip_down(tz->id, trip,
369 tz->temperature);
370 }
371
372 if (type == THERMAL_TRIP_CRITICAL || type == THERMAL_TRIP_HOT)
373 handle_critical_trips(tz, trip, trip_temp, type);
374 else
375 handle_non_critical_trips(tz, trip);
376}
377
378static void update_temperature(struct thermal_zone_device *tz)
379{
380 int temp, ret;
381
382 ret = __thermal_zone_get_temp(tz, &temp);
383 if (ret) {
384 if (ret != -EAGAIN)
385 dev_warn(&tz->device,
386 "failed to read out thermal zone (%d)\n",
387 ret);
388 return;
389 }
390
391 tz->last_temperature = tz->temperature;
392 tz->temperature = temp;
393
394 trace_thermal_temperature(tz);
395
396 thermal_genl_sampling_temp(tz->id, temp);
397}
398
399static void thermal_zone_device_init(struct thermal_zone_device *tz)
400{
401 struct thermal_instance *pos;
402 tz->temperature = THERMAL_TEMP_INVALID;
403 tz->prev_low_trip = -INT_MAX;
404 tz->prev_high_trip = INT_MAX;
405 list_for_each_entry(pos, &tz->thermal_instances, tz_node)
406 pos->initialized = false;
407}
408
409void __thermal_zone_device_update(struct thermal_zone_device *tz,
410 enum thermal_notify_event event)
411{
412 int count;
413
414 if (atomic_read(&in_suspend))
415 return;
416
417 if (WARN_ONCE(!tz->ops->get_temp,
418 "'%s' must not be called without 'get_temp' ops set\n",
419 __func__))
420 return;
421
422 if (!thermal_zone_device_is_enabled(tz))
423 return;
424
425 update_temperature(tz);
426
427 __thermal_zone_set_trips(tz);
428
429 tz->notify_event = event;
430
431 for (count = 0; count < tz->num_trips; count++)
432 handle_thermal_trip(tz, count);
433
434 monitor_thermal_zone(tz);
435}
436
437static int thermal_zone_device_set_mode(struct thermal_zone_device *tz,
438 enum thermal_device_mode mode)
439{
440 int ret = 0;
441
442 mutex_lock(&tz->lock);
443
444 /* do nothing if mode isn't changing */
445 if (mode == tz->mode) {
446 mutex_unlock(&tz->lock);
447
448 return ret;
449 }
450
451 if (!device_is_registered(&tz->device)) {
452 mutex_unlock(&tz->lock);
453
454 return -ENODEV;
455 }
456
457 if (tz->ops->change_mode)
458 ret = tz->ops->change_mode(tz, mode);
459
460 if (!ret)
461 tz->mode = mode;
462
463 __thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
464
465 mutex_unlock(&tz->lock);
466
467 if (mode == THERMAL_DEVICE_ENABLED)
468 thermal_notify_tz_enable(tz->id);
469 else
470 thermal_notify_tz_disable(tz->id);
471
472 return ret;
473}
474
475int thermal_zone_device_enable(struct thermal_zone_device *tz)
476{
477 return thermal_zone_device_set_mode(tz, THERMAL_DEVICE_ENABLED);
478}
479EXPORT_SYMBOL_GPL(thermal_zone_device_enable);
480
481int thermal_zone_device_disable(struct thermal_zone_device *tz)
482{
483 return thermal_zone_device_set_mode(tz, THERMAL_DEVICE_DISABLED);
484}
485EXPORT_SYMBOL_GPL(thermal_zone_device_disable);
486
487int thermal_zone_device_is_enabled(struct thermal_zone_device *tz)
488{
489 lockdep_assert_held(&tz->lock);
490
491 return tz->mode == THERMAL_DEVICE_ENABLED;
492}
493
494void thermal_zone_device_update(struct thermal_zone_device *tz,
495 enum thermal_notify_event event)
496{
497 mutex_lock(&tz->lock);
498 if (device_is_registered(&tz->device))
499 __thermal_zone_device_update(tz, event);
500 mutex_unlock(&tz->lock);
501}
502EXPORT_SYMBOL_GPL(thermal_zone_device_update);
503
504static void thermal_zone_device_check(struct work_struct *work)
505{
506 struct thermal_zone_device *tz = container_of(work, struct
507 thermal_zone_device,
508 poll_queue.work);
509 thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
510}
511
512int for_each_thermal_governor(int (*cb)(struct thermal_governor *, void *),
513 void *data)
514{
515 struct thermal_governor *gov;
516 int ret = 0;
517
518 mutex_lock(&thermal_governor_lock);
519 list_for_each_entry(gov, &thermal_governor_list, governor_list) {
520 ret = cb(gov, data);
521 if (ret)
522 break;
523 }
524 mutex_unlock(&thermal_governor_lock);
525
526 return ret;
527}
528
529int for_each_thermal_cooling_device(int (*cb)(struct thermal_cooling_device *,
530 void *), void *data)
531{
532 struct thermal_cooling_device *cdev;
533 int ret = 0;
534
535 mutex_lock(&thermal_list_lock);
536 list_for_each_entry(cdev, &thermal_cdev_list, node) {
537 ret = cb(cdev, data);
538 if (ret)
539 break;
540 }
541 mutex_unlock(&thermal_list_lock);
542
543 return ret;
544}
545
546int for_each_thermal_zone(int (*cb)(struct thermal_zone_device *, void *),
547 void *data)
548{
549 struct thermal_zone_device *tz;
550 int ret = 0;
551
552 mutex_lock(&thermal_list_lock);
553 list_for_each_entry(tz, &thermal_tz_list, node) {
554 ret = cb(tz, data);
555 if (ret)
556 break;
557 }
558 mutex_unlock(&thermal_list_lock);
559
560 return ret;
561}
562
563struct thermal_zone_device *thermal_zone_get_by_id(int id)
564{
565 struct thermal_zone_device *tz, *match = NULL;
566
567 mutex_lock(&thermal_list_lock);
568 list_for_each_entry(tz, &thermal_tz_list, node) {
569 if (tz->id == id) {
570 match = tz;
571 break;
572 }
573 }
574 mutex_unlock(&thermal_list_lock);
575
576 return match;
577}
578
579/*
580 * Device management section: cooling devices, zones devices, and binding
581 *
582 * Set of functions provided by the thermal core for:
583 * - cooling devices lifecycle: registration, unregistration,
584 * binding, and unbinding.
585 * - thermal zone devices lifecycle: registration, unregistration,
586 * binding, and unbinding.
587 */
588
589/**
590 * thermal_zone_bind_cooling_device() - bind a cooling device to a thermal zone
591 * @tz: pointer to struct thermal_zone_device
592 * @trip: indicates which trip point the cooling devices is
593 * associated with in this thermal zone.
594 * @cdev: pointer to struct thermal_cooling_device
595 * @upper: the Maximum cooling state for this trip point.
596 * THERMAL_NO_LIMIT means no upper limit,
597 * and the cooling device can be in max_state.
598 * @lower: the Minimum cooling state can be used for this trip point.
599 * THERMAL_NO_LIMIT means no lower limit,
600 * and the cooling device can be in cooling state 0.
601 * @weight: The weight of the cooling device to be bound to the
602 * thermal zone. Use THERMAL_WEIGHT_DEFAULT for the
603 * default value
604 *
605 * This interface function bind a thermal cooling device to the certain trip
606 * point of a thermal zone device.
607 * This function is usually called in the thermal zone device .bind callback.
608 *
609 * Return: 0 on success, the proper error value otherwise.
610 */
611int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz,
612 int trip,
613 struct thermal_cooling_device *cdev,
614 unsigned long upper, unsigned long lower,
615 unsigned int weight)
616{
617 struct thermal_instance *dev;
618 struct thermal_instance *pos;
619 struct thermal_zone_device *pos1;
620 struct thermal_cooling_device *pos2;
621 int result;
622
623 if (trip >= tz->num_trips || trip < 0)
624 return -EINVAL;
625
626 list_for_each_entry(pos1, &thermal_tz_list, node) {
627 if (pos1 == tz)
628 break;
629 }
630 list_for_each_entry(pos2, &thermal_cdev_list, node) {
631 if (pos2 == cdev)
632 break;
633 }
634
635 if (tz != pos1 || cdev != pos2)
636 return -EINVAL;
637
638 /* lower default 0, upper default max_state */
639 lower = lower == THERMAL_NO_LIMIT ? 0 : lower;
640 upper = upper == THERMAL_NO_LIMIT ? cdev->max_state : upper;
641
642 if (lower > upper || upper > cdev->max_state)
643 return -EINVAL;
644
645 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
646 if (!dev)
647 return -ENOMEM;
648 dev->tz = tz;
649 dev->cdev = cdev;
650 dev->trip = trip;
651 dev->upper = upper;
652 dev->lower = lower;
653 dev->target = THERMAL_NO_TARGET;
654 dev->weight = weight;
655
656 result = ida_alloc(&tz->ida, GFP_KERNEL);
657 if (result < 0)
658 goto free_mem;
659
660 dev->id = result;
661 sprintf(dev->name, "cdev%d", dev->id);
662 result =
663 sysfs_create_link(&tz->device.kobj, &cdev->device.kobj, dev->name);
664 if (result)
665 goto release_ida;
666
667 sprintf(dev->attr_name, "cdev%d_trip_point", dev->id);
668 sysfs_attr_init(&dev->attr.attr);
669 dev->attr.attr.name = dev->attr_name;
670 dev->attr.attr.mode = 0444;
671 dev->attr.show = trip_point_show;
672 result = device_create_file(&tz->device, &dev->attr);
673 if (result)
674 goto remove_symbol_link;
675
676 sprintf(dev->weight_attr_name, "cdev%d_weight", dev->id);
677 sysfs_attr_init(&dev->weight_attr.attr);
678 dev->weight_attr.attr.name = dev->weight_attr_name;
679 dev->weight_attr.attr.mode = S_IWUSR | S_IRUGO;
680 dev->weight_attr.show = weight_show;
681 dev->weight_attr.store = weight_store;
682 result = device_create_file(&tz->device, &dev->weight_attr);
683 if (result)
684 goto remove_trip_file;
685
686 mutex_lock(&tz->lock);
687 mutex_lock(&cdev->lock);
688 list_for_each_entry(pos, &tz->thermal_instances, tz_node)
689 if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
690 result = -EEXIST;
691 break;
692 }
693 if (!result) {
694 list_add_tail(&dev->tz_node, &tz->thermal_instances);
695 list_add_tail(&dev->cdev_node, &cdev->thermal_instances);
696 atomic_set(&tz->need_update, 1);
697 }
698 mutex_unlock(&cdev->lock);
699 mutex_unlock(&tz->lock);
700
701 if (!result)
702 return 0;
703
704 device_remove_file(&tz->device, &dev->weight_attr);
705remove_trip_file:
706 device_remove_file(&tz->device, &dev->attr);
707remove_symbol_link:
708 sysfs_remove_link(&tz->device.kobj, dev->name);
709release_ida:
710 ida_free(&tz->ida, dev->id);
711free_mem:
712 kfree(dev);
713 return result;
714}
715EXPORT_SYMBOL_GPL(thermal_zone_bind_cooling_device);
716
717/**
718 * thermal_zone_unbind_cooling_device() - unbind a cooling device from a
719 * thermal zone.
720 * @tz: pointer to a struct thermal_zone_device.
721 * @trip: indicates which trip point the cooling devices is
722 * associated with in this thermal zone.
723 * @cdev: pointer to a struct thermal_cooling_device.
724 *
725 * This interface function unbind a thermal cooling device from the certain
726 * trip point of a thermal zone device.
727 * This function is usually called in the thermal zone device .unbind callback.
728 *
729 * Return: 0 on success, the proper error value otherwise.
730 */
731int thermal_zone_unbind_cooling_device(struct thermal_zone_device *tz,
732 int trip,
733 struct thermal_cooling_device *cdev)
734{
735 struct thermal_instance *pos, *next;
736
737 mutex_lock(&tz->lock);
738 mutex_lock(&cdev->lock);
739 list_for_each_entry_safe(pos, next, &tz->thermal_instances, tz_node) {
740 if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
741 list_del(&pos->tz_node);
742 list_del(&pos->cdev_node);
743 mutex_unlock(&cdev->lock);
744 mutex_unlock(&tz->lock);
745 goto unbind;
746 }
747 }
748 mutex_unlock(&cdev->lock);
749 mutex_unlock(&tz->lock);
750
751 return -ENODEV;
752
753unbind:
754 device_remove_file(&tz->device, &pos->weight_attr);
755 device_remove_file(&tz->device, &pos->attr);
756 sysfs_remove_link(&tz->device.kobj, pos->name);
757 ida_free(&tz->ida, pos->id);
758 kfree(pos);
759 return 0;
760}
761EXPORT_SYMBOL_GPL(thermal_zone_unbind_cooling_device);
762
763static void thermal_release(struct device *dev)
764{
765 struct thermal_zone_device *tz;
766 struct thermal_cooling_device *cdev;
767
768 if (!strncmp(dev_name(dev), "thermal_zone",
769 sizeof("thermal_zone") - 1)) {
770 tz = to_thermal_zone(dev);
771 thermal_zone_destroy_device_groups(tz);
772 mutex_destroy(&tz->lock);
773 kfree(tz);
774 } else if (!strncmp(dev_name(dev), "cooling_device",
775 sizeof("cooling_device") - 1)) {
776 cdev = to_cooling_device(dev);
777 kfree(cdev);
778 }
779}
780
781static struct class thermal_class = {
782 .name = "thermal",
783 .dev_release = thermal_release,
784};
785
786static inline
787void print_bind_err_msg(struct thermal_zone_device *tz,
788 struct thermal_cooling_device *cdev, int ret)
789{
790 dev_err(&tz->device, "binding zone %s with cdev %s failed:%d\n",
791 tz->type, cdev->type, ret);
792}
793
794static void __bind(struct thermal_zone_device *tz, int mask,
795 struct thermal_cooling_device *cdev,
796 unsigned long *limits,
797 unsigned int weight)
798{
799 int i, ret;
800
801 for (i = 0; i < tz->num_trips; i++) {
802 if (mask & (1 << i)) {
803 unsigned long upper, lower;
804
805 upper = THERMAL_NO_LIMIT;
806 lower = THERMAL_NO_LIMIT;
807 if (limits) {
808 lower = limits[i * 2];
809 upper = limits[i * 2 + 1];
810 }
811 ret = thermal_zone_bind_cooling_device(tz, i, cdev,
812 upper, lower,
813 weight);
814 if (ret)
815 print_bind_err_msg(tz, cdev, ret);
816 }
817 }
818}
819
820static void bind_cdev(struct thermal_cooling_device *cdev)
821{
822 int i, ret;
823 const struct thermal_zone_params *tzp;
824 struct thermal_zone_device *pos = NULL;
825
826 mutex_lock(&thermal_list_lock);
827
828 list_for_each_entry(pos, &thermal_tz_list, node) {
829 if (!pos->tzp && !pos->ops->bind)
830 continue;
831
832 if (pos->ops->bind) {
833 ret = pos->ops->bind(pos, cdev);
834 if (ret)
835 print_bind_err_msg(pos, cdev, ret);
836 continue;
837 }
838
839 tzp = pos->tzp;
840 if (!tzp || !tzp->tbp)
841 continue;
842
843 for (i = 0; i < tzp->num_tbps; i++) {
844 if (tzp->tbp[i].cdev || !tzp->tbp[i].match)
845 continue;
846 if (tzp->tbp[i].match(pos, cdev))
847 continue;
848 tzp->tbp[i].cdev = cdev;
849 __bind(pos, tzp->tbp[i].trip_mask, cdev,
850 tzp->tbp[i].binding_limits,
851 tzp->tbp[i].weight);
852 }
853 }
854
855 mutex_unlock(&thermal_list_lock);
856}
857
858/**
859 * __thermal_cooling_device_register() - register a new thermal cooling device
860 * @np: a pointer to a device tree node.
861 * @type: the thermal cooling device type.
862 * @devdata: device private data.
863 * @ops: standard thermal cooling devices callbacks.
864 *
865 * This interface function adds a new thermal cooling device (fan/processor/...)
866 * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
867 * to all the thermal zone devices registered at the same time.
868 * It also gives the opportunity to link the cooling device to a device tree
869 * node, so that it can be bound to a thermal zone created out of device tree.
870 *
871 * Return: a pointer to the created struct thermal_cooling_device or an
872 * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
873 */
874static struct thermal_cooling_device *
875__thermal_cooling_device_register(struct device_node *np,
876 const char *type, void *devdata,
877 const struct thermal_cooling_device_ops *ops)
878{
879 struct thermal_cooling_device *cdev;
880 struct thermal_zone_device *pos = NULL;
881 int id, ret;
882
883 if (!ops || !ops->get_max_state || !ops->get_cur_state ||
884 !ops->set_cur_state)
885 return ERR_PTR(-EINVAL);
886
887 cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
888 if (!cdev)
889 return ERR_PTR(-ENOMEM);
890
891 ret = ida_alloc(&thermal_cdev_ida, GFP_KERNEL);
892 if (ret < 0)
893 goto out_kfree_cdev;
894 cdev->id = ret;
895 id = ret;
896
897 cdev->type = kstrdup(type ? type : "", GFP_KERNEL);
898 if (!cdev->type) {
899 ret = -ENOMEM;
900 goto out_ida_remove;
901 }
902
903 mutex_init(&cdev->lock);
904 INIT_LIST_HEAD(&cdev->thermal_instances);
905 cdev->np = np;
906 cdev->ops = ops;
907 cdev->updated = false;
908 cdev->device.class = &thermal_class;
909 cdev->devdata = devdata;
910
911 ret = cdev->ops->get_max_state(cdev, &cdev->max_state);
912 if (ret) {
913 kfree(cdev->type);
914 goto out_ida_remove;
915 }
916
917 thermal_cooling_device_setup_sysfs(cdev);
918
919 ret = dev_set_name(&cdev->device, "cooling_device%d", cdev->id);
920 if (ret) {
921 kfree(cdev->type);
922 thermal_cooling_device_destroy_sysfs(cdev);
923 goto out_ida_remove;
924 }
925
926 ret = device_register(&cdev->device);
927 if (ret)
928 goto out_kfree_type;
929
930 /* Add 'this' new cdev to the global cdev list */
931 mutex_lock(&thermal_list_lock);
932 list_add(&cdev->node, &thermal_cdev_list);
933 mutex_unlock(&thermal_list_lock);
934
935 /* Update binding information for 'this' new cdev */
936 bind_cdev(cdev);
937
938 mutex_lock(&thermal_list_lock);
939 list_for_each_entry(pos, &thermal_tz_list, node)
940 if (atomic_cmpxchg(&pos->need_update, 1, 0))
941 thermal_zone_device_update(pos,
942 THERMAL_EVENT_UNSPECIFIED);
943 mutex_unlock(&thermal_list_lock);
944
945 return cdev;
946
947out_kfree_type:
948 thermal_cooling_device_destroy_sysfs(cdev);
949 kfree(cdev->type);
950 put_device(&cdev->device);
951
952 /* thermal_release() takes care of the rest */
953 cdev = NULL;
954out_ida_remove:
955 ida_free(&thermal_cdev_ida, id);
956out_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 */
974struct thermal_cooling_device *
975thermal_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}
980EXPORT_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 */
997struct thermal_cooling_device *
998thermal_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}
1004EXPORT_SYMBOL_GPL(thermal_of_cooling_device_register);
1005
1006static 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 */
1029struct thermal_cooling_device *
1030devm_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}
1053EXPORT_SYMBOL_GPL(devm_thermal_of_cooling_device_register);
1054
1055static 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->num_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 */
1072void 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_free(&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}
1120EXPORT_SYMBOL_GPL(thermal_cooling_device_unregister);
1121
1122static 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 }
1158exit:
1159 mutex_unlock(&thermal_list_lock);
1160}
1161
1162static void thermal_set_delay_jiffies(unsigned long *delay_jiffies, int delay_ms)
1163{
1164 *delay_jiffies = msecs_to_jiffies(delay_ms);
1165 if (delay_ms > 1000)
1166 *delay_jiffies = round_jiffies(*delay_jiffies);
1167}
1168
1169/**
1170 * thermal_zone_device_register_with_trips() - register a new thermal zone device
1171 * @type: the thermal zone device type
1172 * @trips: a pointer to an array of thermal trips
1173 * @num_trips: the number of trip points the thermal zone support
1174 * @mask: a bit string indicating the writeablility of trip points
1175 * @devdata: private device data
1176 * @ops: standard thermal zone device callbacks
1177 * @tzp: thermal zone platform parameters
1178 * @passive_delay: number of milliseconds to wait between polls when
1179 * performing passive cooling
1180 * @polling_delay: number of milliseconds to wait between polls when checking
1181 * whether trip points have been crossed (0 for interrupt
1182 * driven systems)
1183 *
1184 * This interface function adds a new thermal zone device (sensor) to
1185 * /sys/class/thermal folder as thermal_zone[0-*]. It tries to bind all the
1186 * thermal cooling devices registered at the same time.
1187 * thermal_zone_device_unregister() must be called when the device is no
1188 * longer needed. The passive cooling depends on the .get_trend() return value.
1189 *
1190 * Return: a pointer to the created struct thermal_zone_device or an
1191 * in case of error, an ERR_PTR. Caller must check return value with
1192 * IS_ERR*() helpers.
1193 */
1194struct thermal_zone_device *
1195thermal_zone_device_register_with_trips(const char *type, struct thermal_trip *trips, int num_trips, int mask,
1196 void *devdata, struct thermal_zone_device_ops *ops,
1197 struct thermal_zone_params *tzp, int passive_delay,
1198 int polling_delay)
1199{
1200 struct thermal_zone_device *tz;
1201 enum thermal_trip_type trip_type;
1202 int trip_temp;
1203 int id;
1204 int result;
1205 int count;
1206 struct thermal_governor *governor;
1207
1208 if (!type || strlen(type) == 0) {
1209 pr_err("No thermal zone type defined\n");
1210 return ERR_PTR(-EINVAL);
1211 }
1212
1213 if (strlen(type) >= THERMAL_NAME_LENGTH) {
1214 pr_err("Thermal zone name (%s) too long, should be under %d chars\n",
1215 type, THERMAL_NAME_LENGTH);
1216 return ERR_PTR(-EINVAL);
1217 }
1218
1219 /*
1220 * Max trip count can't exceed 31 as the "mask >> num_trips" condition.
1221 * For example, shifting by 32 will result in compiler warning:
1222 * warning: right shift count >= width of type [-Wshift-count- overflow]
1223 *
1224 * Also "mask >> num_trips" will always be true with 32 bit shift.
1225 * E.g. mask = 0x80000000 for trip id 31 to be RW. Then
1226 * mask >> 32 = 0x80000000
1227 * This will result in failure for the below condition.
1228 *
1229 * Check will be true when the bit 31 of the mask is set.
1230 * 32 bit shift will cause overflow of 4 byte integer.
1231 */
1232 if (num_trips > (BITS_PER_TYPE(int) - 1) || num_trips < 0 || mask >> num_trips) {
1233 pr_err("Incorrect number of thermal trips\n");
1234 return ERR_PTR(-EINVAL);
1235 }
1236
1237 if (!ops) {
1238 pr_err("Thermal zone device ops not defined\n");
1239 return ERR_PTR(-EINVAL);
1240 }
1241
1242 if (num_trips > 0 && (!ops->get_trip_type || !ops->get_trip_temp))
1243 return ERR_PTR(-EINVAL);
1244
1245 tz = kzalloc(sizeof(*tz), GFP_KERNEL);
1246 if (!tz)
1247 return ERR_PTR(-ENOMEM);
1248
1249 INIT_LIST_HEAD(&tz->thermal_instances);
1250 ida_init(&tz->ida);
1251 mutex_init(&tz->lock);
1252 id = ida_alloc(&thermal_tz_ida, GFP_KERNEL);
1253 if (id < 0) {
1254 result = id;
1255 goto free_tz;
1256 }
1257
1258 tz->id = id;
1259 strscpy(tz->type, type, sizeof(tz->type));
1260
1261 if (!ops->critical)
1262 ops->critical = thermal_zone_device_critical;
1263
1264 tz->ops = ops;
1265 tz->tzp = tzp;
1266 tz->device.class = &thermal_class;
1267 tz->devdata = devdata;
1268 tz->trips = trips;
1269 tz->num_trips = num_trips;
1270
1271 thermal_set_delay_jiffies(&tz->passive_delay_jiffies, passive_delay);
1272 thermal_set_delay_jiffies(&tz->polling_delay_jiffies, polling_delay);
1273
1274 /* sys I/F */
1275 /* Add nodes that are always present via .groups */
1276 result = thermal_zone_create_device_groups(tz, mask);
1277 if (result)
1278 goto remove_id;
1279
1280 /* A new thermal zone needs to be updated anyway. */
1281 atomic_set(&tz->need_update, 1);
1282
1283 result = dev_set_name(&tz->device, "thermal_zone%d", tz->id);
1284 if (result) {
1285 thermal_zone_destroy_device_groups(tz);
1286 goto remove_id;
1287 }
1288 result = device_register(&tz->device);
1289 if (result)
1290 goto release_device;
1291
1292 for (count = 0; count < num_trips; count++) {
1293 if (tz->ops->get_trip_type(tz, count, &trip_type) ||
1294 tz->ops->get_trip_temp(tz, count, &trip_temp) ||
1295 !trip_temp)
1296 set_bit(count, &tz->trips_disabled);
1297 }
1298
1299 /* Update 'this' zone's governor information */
1300 mutex_lock(&thermal_governor_lock);
1301
1302 if (tz->tzp)
1303 governor = __find_governor(tz->tzp->governor_name);
1304 else
1305 governor = def_governor;
1306
1307 result = thermal_set_governor(tz, governor);
1308 if (result) {
1309 mutex_unlock(&thermal_governor_lock);
1310 goto unregister;
1311 }
1312
1313 mutex_unlock(&thermal_governor_lock);
1314
1315 if (!tz->tzp || !tz->tzp->no_hwmon) {
1316 result = thermal_add_hwmon_sysfs(tz);
1317 if (result)
1318 goto unregister;
1319 }
1320
1321 mutex_lock(&thermal_list_lock);
1322 list_add_tail(&tz->node, &thermal_tz_list);
1323 mutex_unlock(&thermal_list_lock);
1324
1325 /* Bind cooling devices for this zone */
1326 bind_tz(tz);
1327
1328 INIT_DELAYED_WORK(&tz->poll_queue, thermal_zone_device_check);
1329
1330 thermal_zone_device_init(tz);
1331 /* Update the new thermal zone and mark it as already updated. */
1332 if (atomic_cmpxchg(&tz->need_update, 1, 0))
1333 thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
1334
1335 thermal_notify_tz_create(tz->id, tz->type);
1336
1337 return tz;
1338
1339unregister:
1340 device_del(&tz->device);
1341release_device:
1342 put_device(&tz->device);
1343 tz = NULL;
1344remove_id:
1345 ida_free(&thermal_tz_ida, id);
1346free_tz:
1347 kfree(tz);
1348 return ERR_PTR(result);
1349}
1350EXPORT_SYMBOL_GPL(thermal_zone_device_register_with_trips);
1351
1352struct thermal_zone_device *thermal_zone_device_register(const char *type, int ntrips, int mask,
1353 void *devdata, struct thermal_zone_device_ops *ops,
1354 struct thermal_zone_params *tzp, int passive_delay,
1355 int polling_delay)
1356{
1357 return thermal_zone_device_register_with_trips(type, NULL, ntrips, mask,
1358 devdata, ops, tzp,
1359 passive_delay, polling_delay);
1360}
1361EXPORT_SYMBOL_GPL(thermal_zone_device_register);
1362
1363/**
1364 * thermal_zone_device_unregister - removes the registered thermal zone device
1365 * @tz: the thermal zone device to remove
1366 */
1367void thermal_zone_device_unregister(struct thermal_zone_device *tz)
1368{
1369 int i, tz_id;
1370 const struct thermal_zone_params *tzp;
1371 struct thermal_cooling_device *cdev;
1372 struct thermal_zone_device *pos = NULL;
1373
1374 if (!tz)
1375 return;
1376
1377 tzp = tz->tzp;
1378 tz_id = tz->id;
1379
1380 mutex_lock(&thermal_list_lock);
1381 list_for_each_entry(pos, &thermal_tz_list, node)
1382 if (pos == tz)
1383 break;
1384 if (pos != tz) {
1385 /* thermal zone device not found */
1386 mutex_unlock(&thermal_list_lock);
1387 return;
1388 }
1389 list_del(&tz->node);
1390
1391 /* Unbind all cdevs associated with 'this' thermal zone */
1392 list_for_each_entry(cdev, &thermal_cdev_list, node) {
1393 if (tz->ops->unbind) {
1394 tz->ops->unbind(tz, cdev);
1395 continue;
1396 }
1397
1398 if (!tzp || !tzp->tbp)
1399 break;
1400
1401 for (i = 0; i < tzp->num_tbps; i++) {
1402 if (tzp->tbp[i].cdev == cdev) {
1403 __unbind(tz, tzp->tbp[i].trip_mask, cdev);
1404 tzp->tbp[i].cdev = NULL;
1405 }
1406 }
1407 }
1408
1409 mutex_unlock(&thermal_list_lock);
1410
1411 cancel_delayed_work_sync(&tz->poll_queue);
1412
1413 thermal_set_governor(tz, NULL);
1414
1415 thermal_remove_hwmon_sysfs(tz);
1416 ida_free(&thermal_tz_ida, tz->id);
1417 ida_destroy(&tz->ida);
1418
1419 mutex_lock(&tz->lock);
1420 device_del(&tz->device);
1421 mutex_unlock(&tz->lock);
1422
1423 put_device(&tz->device);
1424
1425 thermal_notify_tz_delete(tz_id);
1426}
1427EXPORT_SYMBOL_GPL(thermal_zone_device_unregister);
1428
1429/**
1430 * thermal_zone_get_zone_by_name() - search for a zone and returns its ref
1431 * @name: thermal zone name to fetch the temperature
1432 *
1433 * When only one zone is found with the passed name, returns a reference to it.
1434 *
1435 * Return: On success returns a reference to an unique thermal zone with
1436 * matching name equals to @name, an ERR_PTR otherwise (-EINVAL for invalid
1437 * paramenters, -ENODEV for not found and -EEXIST for multiple matches).
1438 */
1439struct thermal_zone_device *thermal_zone_get_zone_by_name(const char *name)
1440{
1441 struct thermal_zone_device *pos = NULL, *ref = ERR_PTR(-EINVAL);
1442 unsigned int found = 0;
1443
1444 if (!name)
1445 goto exit;
1446
1447 mutex_lock(&thermal_list_lock);
1448 list_for_each_entry(pos, &thermal_tz_list, node)
1449 if (!strncasecmp(name, pos->type, THERMAL_NAME_LENGTH)) {
1450 found++;
1451 ref = pos;
1452 }
1453 mutex_unlock(&thermal_list_lock);
1454
1455 /* nothing has been found, thus an error code for it */
1456 if (found == 0)
1457 ref = ERR_PTR(-ENODEV);
1458 else if (found > 1)
1459 /* Success only when an unique zone is found */
1460 ref = ERR_PTR(-EEXIST);
1461
1462exit:
1463 return ref;
1464}
1465EXPORT_SYMBOL_GPL(thermal_zone_get_zone_by_name);
1466
1467static int thermal_pm_notify(struct notifier_block *nb,
1468 unsigned long mode, void *_unused)
1469{
1470 struct thermal_zone_device *tz;
1471
1472 switch (mode) {
1473 case PM_HIBERNATION_PREPARE:
1474 case PM_RESTORE_PREPARE:
1475 case PM_SUSPEND_PREPARE:
1476 atomic_set(&in_suspend, 1);
1477 break;
1478 case PM_POST_HIBERNATION:
1479 case PM_POST_RESTORE:
1480 case PM_POST_SUSPEND:
1481 atomic_set(&in_suspend, 0);
1482 list_for_each_entry(tz, &thermal_tz_list, node) {
1483 thermal_zone_device_init(tz);
1484 thermal_zone_device_update(tz,
1485 THERMAL_EVENT_UNSPECIFIED);
1486 }
1487 break;
1488 default:
1489 break;
1490 }
1491 return 0;
1492}
1493
1494static struct notifier_block thermal_pm_nb = {
1495 .notifier_call = thermal_pm_notify,
1496};
1497
1498static int __init thermal_init(void)
1499{
1500 int result;
1501
1502 result = thermal_netlink_init();
1503 if (result)
1504 goto error;
1505
1506 result = thermal_register_governors();
1507 if (result)
1508 goto error;
1509
1510 result = class_register(&thermal_class);
1511 if (result)
1512 goto unregister_governors;
1513
1514 result = register_pm_notifier(&thermal_pm_nb);
1515 if (result)
1516 pr_warn("Thermal: Can not register suspend notifier, return %d\n",
1517 result);
1518
1519 return 0;
1520
1521unregister_governors:
1522 thermal_unregister_governors();
1523error:
1524 ida_destroy(&thermal_tz_ida);
1525 ida_destroy(&thermal_cdev_ida);
1526 mutex_destroy(&thermal_list_lock);
1527 mutex_destroy(&thermal_governor_lock);
1528 return result;
1529}
1530postcore_initcall(thermal_init);