1// SPDX-License-Identifier: GPL-2.0
2/*
3 * thermal.c - Generic Thermal Management Sysfs support.
4 *
5 * Copyright (C) 2008 Intel Corp
6 * Copyright (C) 2008 Zhang Rui <rui.zhang@intel.com>
7 * Copyright (C) 2008 Sujith Thomas <sujith.thomas@intel.com>
8 */
9
10#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11
12#include <linux/device.h>
13#include <linux/err.h>
14#include <linux/export.h>
15#include <linux/slab.h>
16#include <linux/kdev_t.h>
17#include <linux/idr.h>
18#include <linux/thermal.h>
19#include <linux/reboot.h>
20#include <linux/string.h>
21#include <linux/of.h>
22#include <linux/suspend.h>
23
24#define CREATE_TRACE_POINTS
25#include "thermal_trace.h"
26
27#include "thermal_core.h"
28#include "thermal_hwmon.h"
29
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(s1: name, s2: 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, failed_gov_name: 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(name: governor->name)) {
130 bool match_default;
131
132 err = 0;
133 list_add(new: &governor->governor_list, head: &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(s1: name, s2: governor->name, THERMAL_NAME_LENGTH)) {
155 int ret;
156
157 ret = thermal_set_governor(tz: pos, new_gov: 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(lock: &thermal_list_lock);
166 mutex_unlock(lock: &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(name: 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(s1: pos->governor->name, s2: governor->name,
187 THERMAL_NAME_LENGTH))
188 thermal_set_governor(tz: pos, NULL);
189 }
190
191 mutex_unlock(lock: &thermal_list_lock);
192 list_del(entry: &governor->governor_list);
193exit:
194 mutex_unlock(lock: &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(dev: &tz->device))
207 goto exit;
208
209 gov = __find_governor(name: strim(policy));
210 if (!gov)
211 goto exit;
212
213 ret = thermal_set_governor(tz, new_gov: gov);
214
215exit:
216 mutex_unlock(lock: &tz->lock);
217 mutex_unlock(lock: &thermal_governor_lock);
218
219 thermal_notify_tz_gov_change(tz_id: tz->id, name: 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 += sysfs_emit_at(buf, at: count, fmt: "%s ", pos->name);
233 }
234 count += sysfs_emit_at(buf, at: count, fmt: "\n");
235
236 mutex_unlock(lock: &thermal_governor_lock);
237
238 return count;
239}
240
241static void __init thermal_unregister_governors(void)
242{
243 struct thermal_governor **governor;
244
245 for_each_governor_table(governor)
246 thermal_unregister_governor(governor: *governor);
247}
248
249static int __init thermal_register_governors(void)
250{
251 int ret = 0;
252 struct thermal_governor **governor;
253
254 for_each_governor_table(governor) {
255 ret = thermal_register_governor(governor: *governor);
256 if (ret) {
257 pr_err("Failed to register governor: '%s'",
258 (*governor)->name);
259 break;
260 }
261
262 pr_info("Registered thermal governor '%s'",
263 (*governor)->name);
264 }
265
266 if (ret) {
267 struct thermal_governor **gov;
268
269 for_each_governor_table(gov) {
270 if (gov == governor)
271 break;
272 thermal_unregister_governor(governor: *gov);
273 }
274 }
275
276 return ret;
277}
278
279/*
280 * Zone update section: main control loop applied to each zone while monitoring
281 *
282 * in polling mode. The monitoring is done using a workqueue.
283 * Same update may be done on a zone by calling thermal_zone_device_update().
284 *
285 * An update means:
286 * - Non-critical trips will invoke the governor responsible for that zone;
287 * - Hot trips will produce a notification to userspace;
288 * - Critical trip point will cause a system shutdown.
289 */
290static void thermal_zone_device_set_polling(struct thermal_zone_device *tz,
291 unsigned long delay)
292{
293 if (delay)
294 mod_delayed_work(wq: system_freezable_power_efficient_wq,
295 dwork: &tz->poll_queue, delay);
296 else
297 cancel_delayed_work(dwork: &tz->poll_queue);
298}
299
300static void monitor_thermal_zone(struct thermal_zone_device *tz)
301{
302 if (tz->mode != THERMAL_DEVICE_ENABLED)
303 thermal_zone_device_set_polling(tz, delay: 0);
304 else if (tz->passive)
305 thermal_zone_device_set_polling(tz, delay: tz->passive_delay_jiffies);
306 else if (tz->polling_delay_jiffies)
307 thermal_zone_device_set_polling(tz, delay: tz->polling_delay_jiffies);
308}
309
310static void handle_non_critical_trips(struct thermal_zone_device *tz,
311 const struct thermal_trip *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(reason: "Temperature too high", ms_until_forced: poweroff_delay_ms);
329}
330EXPORT_SYMBOL(thermal_zone_device_critical);
331
332static void handle_critical_trips(struct thermal_zone_device *tz,
333 const struct thermal_trip *trip)
334{
335 /* If we have not crossed the trip_temp, we do not care. */
336 if (trip->temperature <= 0 || tz->temperature < trip->temperature)
337 return;
338
339 trace_thermal_zone_trip(tz, trip: thermal_zone_trip_id(tz, trip), trip_type: trip->type);
340
341 if (trip->type == THERMAL_TRIP_CRITICAL)
342 tz->ops->critical(tz);
343 else if (tz->ops->hot)
344 tz->ops->hot(tz);
345}
346
347static void handle_thermal_trip(struct thermal_zone_device *tz,
348 const struct thermal_trip *trip)
349{
350 if (trip->temperature == THERMAL_TEMP_INVALID)
351 return;
352
353 if (tz->last_temperature != THERMAL_TEMP_INVALID) {
354 if (tz->last_temperature < trip->temperature &&
355 tz->temperature >= trip->temperature)
356 thermal_notify_tz_trip_up(tz_id: tz->id,
357 id: thermal_zone_trip_id(tz, trip),
358 temp: tz->temperature);
359 if (tz->last_temperature >= trip->temperature &&
360 tz->temperature < trip->temperature - trip->hysteresis)
361 thermal_notify_tz_trip_down(tz_id: tz->id,
362 id: thermal_zone_trip_id(tz, trip),
363 temp: tz->temperature);
364 }
365
366 if (trip->type == THERMAL_TRIP_CRITICAL || trip->type == THERMAL_TRIP_HOT)
367 handle_critical_trips(tz, trip);
368 else
369 handle_non_critical_trips(tz, trip);
370}
371
372static void update_temperature(struct thermal_zone_device *tz)
373{
374 int temp, ret;
375
376 ret = __thermal_zone_get_temp(tz, temp: &temp);
377 if (ret) {
378 if (ret != -EAGAIN)
379 dev_warn(&tz->device,
380 "failed to read out thermal zone (%d)\n",
381 ret);
382 return;
383 }
384
385 tz->last_temperature = tz->temperature;
386 tz->temperature = temp;
387
388 trace_thermal_temperature(tz);
389
390 thermal_genl_sampling_temp(id: tz->id, temp);
391}
392
393static void thermal_zone_device_init(struct thermal_zone_device *tz)
394{
395 struct thermal_instance *pos;
396 tz->temperature = THERMAL_TEMP_INVALID;
397 tz->prev_low_trip = -INT_MAX;
398 tz->prev_high_trip = INT_MAX;
399 list_for_each_entry(pos, &tz->thermal_instances, tz_node)
400 pos->initialized = false;
401}
402
403void __thermal_zone_device_update(struct thermal_zone_device *tz,
404 enum thermal_notify_event event)
405{
406 const struct thermal_trip *trip;
407
408 if (atomic_read(v: &in_suspend))
409 return;
410
411 if (WARN_ONCE(!tz->ops->get_temp,
412 "'%s' must not be called without 'get_temp' ops set\n",
413 __func__))
414 return;
415
416 if (!thermal_zone_device_is_enabled(tz))
417 return;
418
419 update_temperature(tz);
420
421 __thermal_zone_set_trips(tz);
422
423 tz->notify_event = event;
424
425 for_each_trip(tz, trip)
426 handle_thermal_trip(tz, trip);
427
428 monitor_thermal_zone(tz);
429}
430
431static int thermal_zone_device_set_mode(struct thermal_zone_device *tz,
432 enum thermal_device_mode mode)
433{
434 int ret = 0;
435
436 mutex_lock(&tz->lock);
437
438 /* do nothing if mode isn't changing */
439 if (mode == tz->mode) {
440 mutex_unlock(lock: &tz->lock);
441
442 return ret;
443 }
444
445 if (!device_is_registered(dev: &tz->device)) {
446 mutex_unlock(lock: &tz->lock);
447
448 return -ENODEV;
449 }
450
451 if (tz->ops->change_mode)
452 ret = tz->ops->change_mode(tz, mode);
453
454 if (!ret)
455 tz->mode = mode;
456
457 __thermal_zone_device_update(tz, event: THERMAL_EVENT_UNSPECIFIED);
458
459 mutex_unlock(lock: &tz->lock);
460
461 if (mode == THERMAL_DEVICE_ENABLED)
462 thermal_notify_tz_enable(tz_id: tz->id);
463 else
464 thermal_notify_tz_disable(tz_id: tz->id);
465
466 return ret;
467}
468
469int thermal_zone_device_enable(struct thermal_zone_device *tz)
470{
471 return thermal_zone_device_set_mode(tz, mode: THERMAL_DEVICE_ENABLED);
472}
473EXPORT_SYMBOL_GPL(thermal_zone_device_enable);
474
475int thermal_zone_device_disable(struct thermal_zone_device *tz)
476{
477 return thermal_zone_device_set_mode(tz, mode: THERMAL_DEVICE_DISABLED);
478}
479EXPORT_SYMBOL_GPL(thermal_zone_device_disable);
480
481int thermal_zone_device_is_enabled(struct thermal_zone_device *tz)
482{
483 lockdep_assert_held(&tz->lock);
484
485 return tz->mode == THERMAL_DEVICE_ENABLED;
486}
487
488void thermal_zone_device_update(struct thermal_zone_device *tz,
489 enum thermal_notify_event event)
490{
491 mutex_lock(&tz->lock);
492 if (device_is_registered(dev: &tz->device))
493 __thermal_zone_device_update(tz, event);
494 mutex_unlock(lock: &tz->lock);
495}
496EXPORT_SYMBOL_GPL(thermal_zone_device_update);
497
498static void thermal_zone_device_check(struct work_struct *work)
499{
500 struct thermal_zone_device *tz = container_of(work, struct
501 thermal_zone_device,
502 poll_queue.work);
503 thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
504}
505
506int for_each_thermal_governor(int (*cb)(struct thermal_governor *, void *),
507 void *data)
508{
509 struct thermal_governor *gov;
510 int ret = 0;
511
512 mutex_lock(&thermal_governor_lock);
513 list_for_each_entry(gov, &thermal_governor_list, governor_list) {
514 ret = cb(gov, data);
515 if (ret)
516 break;
517 }
518 mutex_unlock(lock: &thermal_governor_lock);
519
520 return ret;
521}
522
523int for_each_thermal_cooling_device(int (*cb)(struct thermal_cooling_device *,
524 void *), void *data)
525{
526 struct thermal_cooling_device *cdev;
527 int ret = 0;
528
529 mutex_lock(&thermal_list_lock);
530 list_for_each_entry(cdev, &thermal_cdev_list, node) {
531 ret = cb(cdev, data);
532 if (ret)
533 break;
534 }
535 mutex_unlock(lock: &thermal_list_lock);
536
537 return ret;
538}
539
540int for_each_thermal_zone(int (*cb)(struct thermal_zone_device *, void *),
541 void *data)
542{
543 struct thermal_zone_device *tz;
544 int ret = 0;
545
546 mutex_lock(&thermal_list_lock);
547 list_for_each_entry(tz, &thermal_tz_list, node) {
548 ret = cb(tz, data);
549 if (ret)
550 break;
551 }
552 mutex_unlock(lock: &thermal_list_lock);
553
554 return ret;
555}
556
557struct thermal_zone_device *thermal_zone_get_by_id(int id)
558{
559 struct thermal_zone_device *tz, *match = NULL;
560
561 mutex_lock(&thermal_list_lock);
562 list_for_each_entry(tz, &thermal_tz_list, node) {
563 if (tz->id == id) {
564 match = tz;
565 break;
566 }
567 }
568 mutex_unlock(lock: &thermal_list_lock);
569
570 return match;
571}
572
573/*
574 * Device management section: cooling devices, zones devices, and binding
575 *
576 * Set of functions provided by the thermal core for:
577 * - cooling devices lifecycle: registration, unregistration,
578 * binding, and unbinding.
579 * - thermal zone devices lifecycle: registration, unregistration,
580 * binding, and unbinding.
581 */
582
583/**
584 * thermal_bind_cdev_to_trip - bind a cooling device to a thermal zone
585 * @tz: pointer to struct thermal_zone_device
586 * @trip: trip point the cooling devices is associated with in this zone.
587 * @cdev: pointer to struct thermal_cooling_device
588 * @upper: the Maximum cooling state for this trip point.
589 * THERMAL_NO_LIMIT means no upper limit,
590 * and the cooling device can be in max_state.
591 * @lower: the Minimum cooling state can be used for this trip point.
592 * THERMAL_NO_LIMIT means no lower limit,
593 * and the cooling device can be in cooling state 0.
594 * @weight: The weight of the cooling device to be bound to the
595 * thermal zone. Use THERMAL_WEIGHT_DEFAULT for the
596 * default value
597 *
598 * This interface function bind a thermal cooling device to the certain trip
599 * point of a thermal zone device.
600 * This function is usually called in the thermal zone device .bind callback.
601 *
602 * Return: 0 on success, the proper error value otherwise.
603 */
604int thermal_bind_cdev_to_trip(struct thermal_zone_device *tz,
605 const struct thermal_trip *trip,
606 struct thermal_cooling_device *cdev,
607 unsigned long upper, unsigned long lower,
608 unsigned int weight)
609{
610 struct thermal_instance *dev;
611 struct thermal_instance *pos;
612 struct thermal_zone_device *pos1;
613 struct thermal_cooling_device *pos2;
614 bool upper_no_limit;
615 int result;
616
617 list_for_each_entry(pos1, &thermal_tz_list, node) {
618 if (pos1 == tz)
619 break;
620 }
621 list_for_each_entry(pos2, &thermal_cdev_list, node) {
622 if (pos2 == cdev)
623 break;
624 }
625
626 if (tz != pos1 || cdev != pos2)
627 return -EINVAL;
628
629 /* lower default 0, upper default max_state */
630 lower = lower == THERMAL_NO_LIMIT ? 0 : lower;
631
632 if (upper == THERMAL_NO_LIMIT) {
633 upper = cdev->max_state;
634 upper_no_limit = true;
635 } else {
636 upper_no_limit = false;
637 }
638
639 if (lower > upper || upper > cdev->max_state)
640 return -EINVAL;
641
642 dev = kzalloc(size: sizeof(*dev), GFP_KERNEL);
643 if (!dev)
644 return -ENOMEM;
645 dev->tz = tz;
646 dev->cdev = cdev;
647 dev->trip = trip;
648 dev->upper = upper;
649 dev->upper_no_limit = upper_no_limit;
650 dev->lower = lower;
651 dev->target = THERMAL_NO_TARGET;
652 dev->weight = weight;
653
654 result = ida_alloc(ida: &tz->ida, GFP_KERNEL);
655 if (result < 0)
656 goto free_mem;
657
658 dev->id = result;
659 sprintf(buf: dev->name, fmt: "cdev%d", dev->id);
660 result =
661 sysfs_create_link(kobj: &tz->device.kobj, target: &cdev->device.kobj, name: dev->name);
662 if (result)
663 goto release_ida;
664
665 snprintf(buf: dev->attr_name, size: sizeof(dev->attr_name), fmt: "cdev%d_trip_point",
666 dev->id);
667 sysfs_attr_init(&dev->attr.attr);
668 dev->attr.attr.name = dev->attr_name;
669 dev->attr.attr.mode = 0444;
670 dev->attr.show = trip_point_show;
671 result = device_create_file(device: &tz->device, entry: &dev->attr);
672 if (result)
673 goto remove_symbol_link;
674
675 snprintf(buf: dev->weight_attr_name, size: sizeof(dev->weight_attr_name),
676 fmt: "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(device: &tz->device, entry: &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(new: &dev->tz_node, head: &tz->thermal_instances);
695 list_add_tail(new: &dev->cdev_node, head: &cdev->thermal_instances);
696 atomic_set(v: &tz->need_update, i: 1);
697 }
698 mutex_unlock(lock: &cdev->lock);
699 mutex_unlock(lock: &tz->lock);
700
701 if (!result)
702 return 0;
703
704 device_remove_file(dev: &tz->device, attr: &dev->weight_attr);
705remove_trip_file:
706 device_remove_file(dev: &tz->device, attr: &dev->attr);
707remove_symbol_link:
708 sysfs_remove_link(kobj: &tz->device.kobj, name: dev->name);
709release_ida:
710 ida_free(&tz->ida, id: dev->id);
711free_mem:
712 kfree(objp: dev);
713 return result;
714}
715EXPORT_SYMBOL_GPL(thermal_bind_cdev_to_trip);
716
717int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz,
718 int trip_index,
719 struct thermal_cooling_device *cdev,
720 unsigned long upper, unsigned long lower,
721 unsigned int weight)
722{
723 if (trip_index < 0 || trip_index >= tz->num_trips)
724 return -EINVAL;
725
726 return thermal_bind_cdev_to_trip(tz, &tz->trips[trip_index], cdev,
727 upper, lower, weight);
728}
729EXPORT_SYMBOL_GPL(thermal_zone_bind_cooling_device);
730
731/**
732 * thermal_unbind_cdev_from_trip - unbind a cooling device from a thermal zone.
733 * @tz: pointer to a struct thermal_zone_device.
734 * @trip: trip point the cooling devices is associated with in this zone.
735 * @cdev: pointer to a struct thermal_cooling_device.
736 *
737 * This interface function unbind a thermal cooling device from the certain
738 * trip point of a thermal zone device.
739 * This function is usually called in the thermal zone device .unbind callback.
740 *
741 * Return: 0 on success, the proper error value otherwise.
742 */
743int thermal_unbind_cdev_from_trip(struct thermal_zone_device *tz,
744 const struct thermal_trip *trip,
745 struct thermal_cooling_device *cdev)
746{
747 struct thermal_instance *pos, *next;
748
749 mutex_lock(&tz->lock);
750 mutex_lock(&cdev->lock);
751 list_for_each_entry_safe(pos, next, &tz->thermal_instances, tz_node) {
752 if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
753 list_del(entry: &pos->tz_node);
754 list_del(entry: &pos->cdev_node);
755 mutex_unlock(lock: &cdev->lock);
756 mutex_unlock(lock: &tz->lock);
757 goto unbind;
758 }
759 }
760 mutex_unlock(lock: &cdev->lock);
761 mutex_unlock(lock: &tz->lock);
762
763 return -ENODEV;
764
765unbind:
766 device_remove_file(dev: &tz->device, attr: &pos->weight_attr);
767 device_remove_file(dev: &tz->device, attr: &pos->attr);
768 sysfs_remove_link(kobj: &tz->device.kobj, name: pos->name);
769 ida_free(&tz->ida, id: pos->id);
770 kfree(objp: pos);
771 return 0;
772}
773EXPORT_SYMBOL_GPL(thermal_unbind_cdev_from_trip);
774
775int thermal_zone_unbind_cooling_device(struct thermal_zone_device *tz,
776 int trip_index,
777 struct thermal_cooling_device *cdev)
778{
779 if (trip_index < 0 || trip_index >= tz->num_trips)
780 return -EINVAL;
781
782 return thermal_unbind_cdev_from_trip(tz, &tz->trips[trip_index], cdev);
783}
784EXPORT_SYMBOL_GPL(thermal_zone_unbind_cooling_device);
785
786static void thermal_release(struct device *dev)
787{
788 struct thermal_zone_device *tz;
789 struct thermal_cooling_device *cdev;
790
791 if (!strncmp(dev_name(dev), "thermal_zone",
792 sizeof("thermal_zone") - 1)) {
793 tz = to_thermal_zone(dev);
794 thermal_zone_destroy_device_groups(tz);
795 mutex_destroy(lock: &tz->lock);
796 kfree(objp: tz);
797 } else if (!strncmp(dev_name(dev), "cooling_device",
798 sizeof("cooling_device") - 1)) {
799 cdev = to_cooling_device(dev);
800 thermal_cooling_device_destroy_sysfs(cdev);
801 kfree(objp: cdev->type);
802 ida_free(&thermal_cdev_ida, id: cdev->id);
803 kfree(objp: cdev);
804 }
805}
806
807static struct class *thermal_class;
808
809static inline
810void print_bind_err_msg(struct thermal_zone_device *tz,
811 struct thermal_cooling_device *cdev, int ret)
812{
813 dev_err(&tz->device, "binding zone %s with cdev %s failed:%d\n",
814 tz->type, cdev->type, ret);
815}
816
817static void bind_cdev(struct thermal_cooling_device *cdev)
818{
819 int ret;
820 struct thermal_zone_device *pos = NULL;
821
822 list_for_each_entry(pos, &thermal_tz_list, node) {
823 if (pos->ops->bind) {
824 ret = pos->ops->bind(pos, cdev);
825 if (ret)
826 print_bind_err_msg(tz: pos, cdev, ret);
827 }
828 }
829}
830
831/**
832 * __thermal_cooling_device_register() - register a new thermal cooling device
833 * @np: a pointer to a device tree node.
834 * @type: the thermal cooling device type.
835 * @devdata: device private data.
836 * @ops: standard thermal cooling devices callbacks.
837 *
838 * This interface function adds a new thermal cooling device (fan/processor/...)
839 * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
840 * to all the thermal zone devices registered at the same time.
841 * It also gives the opportunity to link the cooling device to a device tree
842 * node, so that it can be bound to a thermal zone created out of device tree.
843 *
844 * Return: a pointer to the created struct thermal_cooling_device or an
845 * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
846 */
847static struct thermal_cooling_device *
848__thermal_cooling_device_register(struct device_node *np,
849 const char *type, void *devdata,
850 const struct thermal_cooling_device_ops *ops)
851{
852 struct thermal_cooling_device *cdev;
853 struct thermal_zone_device *pos = NULL;
854 int id, ret;
855
856 if (!ops || !ops->get_max_state || !ops->get_cur_state ||
857 !ops->set_cur_state)
858 return ERR_PTR(error: -EINVAL);
859
860 if (!thermal_class)
861 return ERR_PTR(error: -ENODEV);
862
863 cdev = kzalloc(size: sizeof(*cdev), GFP_KERNEL);
864 if (!cdev)
865 return ERR_PTR(error: -ENOMEM);
866
867 ret = ida_alloc(ida: &thermal_cdev_ida, GFP_KERNEL);
868 if (ret < 0)
869 goto out_kfree_cdev;
870 cdev->id = ret;
871 id = ret;
872
873 cdev->type = kstrdup(s: type ? type : "", GFP_KERNEL);
874 if (!cdev->type) {
875 ret = -ENOMEM;
876 goto out_ida_remove;
877 }
878
879 mutex_init(&cdev->lock);
880 INIT_LIST_HEAD(list: &cdev->thermal_instances);
881 cdev->np = np;
882 cdev->ops = ops;
883 cdev->updated = false;
884 cdev->device.class = thermal_class;
885 cdev->devdata = devdata;
886
887 ret = cdev->ops->get_max_state(cdev, &cdev->max_state);
888 if (ret)
889 goto out_cdev_type;
890
891 thermal_cooling_device_setup_sysfs(cdev);
892
893 ret = dev_set_name(dev: &cdev->device, name: "cooling_device%d", cdev->id);
894 if (ret)
895 goto out_cooling_dev;
896
897 ret = device_register(dev: &cdev->device);
898 if (ret) {
899 /* thermal_release() handles rest of the cleanup */
900 put_device(dev: &cdev->device);
901 return ERR_PTR(error: ret);
902 }
903
904 /* Add 'this' new cdev to the global cdev list */
905 mutex_lock(&thermal_list_lock);
906
907 list_add(new: &cdev->node, head: &thermal_cdev_list);
908
909 /* Update binding information for 'this' new cdev */
910 bind_cdev(cdev);
911
912 list_for_each_entry(pos, &thermal_tz_list, node)
913 if (atomic_cmpxchg(v: &pos->need_update, old: 1, new: 0))
914 thermal_zone_device_update(pos,
915 THERMAL_EVENT_UNSPECIFIED);
916
917 mutex_unlock(lock: &thermal_list_lock);
918
919 return cdev;
920
921out_cooling_dev:
922 thermal_cooling_device_destroy_sysfs(cdev);
923out_cdev_type:
924 kfree(objp: cdev->type);
925out_ida_remove:
926 ida_free(&thermal_cdev_ida, id);
927out_kfree_cdev:
928 kfree(objp: cdev);
929 return ERR_PTR(error: ret);
930}
931
932/**
933 * thermal_cooling_device_register() - register a new thermal cooling device
934 * @type: the thermal cooling device type.
935 * @devdata: device private data.
936 * @ops: standard thermal cooling devices callbacks.
937 *
938 * This interface function adds a new thermal cooling device (fan/processor/...)
939 * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
940 * to all the thermal zone devices registered at the same time.
941 *
942 * Return: a pointer to the created struct thermal_cooling_device or an
943 * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
944 */
945struct thermal_cooling_device *
946thermal_cooling_device_register(const char *type, void *devdata,
947 const struct thermal_cooling_device_ops *ops)
948{
949 return __thermal_cooling_device_register(NULL, type, devdata, ops);
950}
951EXPORT_SYMBOL_GPL(thermal_cooling_device_register);
952
953/**
954 * thermal_of_cooling_device_register() - register an OF thermal cooling device
955 * @np: a pointer to a device tree node.
956 * @type: the thermal cooling device type.
957 * @devdata: device private data.
958 * @ops: standard thermal cooling devices callbacks.
959 *
960 * This function will register a cooling device with device tree node reference.
961 * This interface function adds a new thermal cooling device (fan/processor/...)
962 * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
963 * to all the thermal zone devices registered at the same time.
964 *
965 * Return: a pointer to the created struct thermal_cooling_device or an
966 * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
967 */
968struct thermal_cooling_device *
969thermal_of_cooling_device_register(struct device_node *np,
970 const char *type, void *devdata,
971 const struct thermal_cooling_device_ops *ops)
972{
973 return __thermal_cooling_device_register(np, type, devdata, ops);
974}
975EXPORT_SYMBOL_GPL(thermal_of_cooling_device_register);
976
977static void thermal_cooling_device_release(struct device *dev, void *res)
978{
979 thermal_cooling_device_unregister(
980 *(struct thermal_cooling_device **)res);
981}
982
983/**
984 * devm_thermal_of_cooling_device_register() - register an OF thermal cooling
985 * device
986 * @dev: a valid struct device pointer of a sensor device.
987 * @np: a pointer to a device tree node.
988 * @type: the thermal cooling device type.
989 * @devdata: device private data.
990 * @ops: standard thermal cooling devices callbacks.
991 *
992 * This function will register a cooling device with device tree node reference.
993 * This interface function adds a new thermal cooling device (fan/processor/...)
994 * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
995 * to all the thermal zone devices registered at the same time.
996 *
997 * Return: a pointer to the created struct thermal_cooling_device or an
998 * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
999 */
1000struct thermal_cooling_device *
1001devm_thermal_of_cooling_device_register(struct device *dev,
1002 struct device_node *np,
1003 char *type, void *devdata,
1004 const struct thermal_cooling_device_ops *ops)
1005{
1006 struct thermal_cooling_device **ptr, *tcd;
1007
1008 ptr = devres_alloc(thermal_cooling_device_release, sizeof(*ptr),
1009 GFP_KERNEL);
1010 if (!ptr)
1011 return ERR_PTR(error: -ENOMEM);
1012
1013 tcd = __thermal_cooling_device_register(np, type, devdata, ops);
1014 if (IS_ERR(ptr: tcd)) {
1015 devres_free(res: ptr);
1016 return tcd;
1017 }
1018
1019 *ptr = tcd;
1020 devres_add(dev, res: ptr);
1021
1022 return tcd;
1023}
1024EXPORT_SYMBOL_GPL(devm_thermal_of_cooling_device_register);
1025
1026static bool thermal_cooling_device_present(struct thermal_cooling_device *cdev)
1027{
1028 struct thermal_cooling_device *pos = NULL;
1029
1030 list_for_each_entry(pos, &thermal_cdev_list, node) {
1031 if (pos == cdev)
1032 return true;
1033 }
1034
1035 return false;
1036}
1037
1038/**
1039 * thermal_cooling_device_update - Update a cooling device object
1040 * @cdev: Target cooling device.
1041 *
1042 * Update @cdev to reflect a change of the underlying hardware or platform.
1043 *
1044 * Must be called when the maximum cooling state of @cdev becomes invalid and so
1045 * its .get_max_state() callback needs to be run to produce the new maximum
1046 * cooling state value.
1047 */
1048void thermal_cooling_device_update(struct thermal_cooling_device *cdev)
1049{
1050 struct thermal_instance *ti;
1051 unsigned long state;
1052
1053 if (IS_ERR_OR_NULL(ptr: cdev))
1054 return;
1055
1056 /*
1057 * Hold thermal_list_lock throughout the update to prevent the device
1058 * from going away while being updated.
1059 */
1060 mutex_lock(&thermal_list_lock);
1061
1062 if (!thermal_cooling_device_present(cdev))
1063 goto unlock_list;
1064
1065 /*
1066 * Update under the cdev lock to prevent the state from being set beyond
1067 * the new limit concurrently.
1068 */
1069 mutex_lock(&cdev->lock);
1070
1071 if (cdev->ops->get_max_state(cdev, &cdev->max_state))
1072 goto unlock;
1073
1074 thermal_cooling_device_stats_reinit(cdev);
1075
1076 list_for_each_entry(ti, &cdev->thermal_instances, cdev_node) {
1077 if (ti->upper == cdev->max_state)
1078 continue;
1079
1080 if (ti->upper < cdev->max_state) {
1081 if (ti->upper_no_limit)
1082 ti->upper = cdev->max_state;
1083
1084 continue;
1085 }
1086
1087 ti->upper = cdev->max_state;
1088 if (ti->lower > ti->upper)
1089 ti->lower = ti->upper;
1090
1091 if (ti->target == THERMAL_NO_TARGET)
1092 continue;
1093
1094 if (ti->target > ti->upper)
1095 ti->target = ti->upper;
1096 }
1097
1098 if (cdev->ops->get_cur_state(cdev, &state) || state > cdev->max_state)
1099 goto unlock;
1100
1101 thermal_cooling_device_stats_update(cdev, new_state: state);
1102
1103unlock:
1104 mutex_unlock(lock: &cdev->lock);
1105
1106unlock_list:
1107 mutex_unlock(lock: &thermal_list_lock);
1108}
1109EXPORT_SYMBOL_GPL(thermal_cooling_device_update);
1110
1111/**
1112 * thermal_cooling_device_unregister - removes a thermal cooling device
1113 * @cdev: the thermal cooling device to remove.
1114 *
1115 * thermal_cooling_device_unregister() must be called when a registered
1116 * thermal cooling device is no longer needed.
1117 */
1118void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev)
1119{
1120 struct thermal_zone_device *tz;
1121
1122 if (!cdev)
1123 return;
1124
1125 mutex_lock(&thermal_list_lock);
1126
1127 if (!thermal_cooling_device_present(cdev)) {
1128 mutex_unlock(lock: &thermal_list_lock);
1129 return;
1130 }
1131
1132 list_del(entry: &cdev->node);
1133
1134 /* Unbind all thermal zones associated with 'this' cdev */
1135 list_for_each_entry(tz, &thermal_tz_list, node) {
1136 if (tz->ops->unbind)
1137 tz->ops->unbind(tz, cdev);
1138 }
1139
1140 mutex_unlock(lock: &thermal_list_lock);
1141
1142 device_unregister(dev: &cdev->device);
1143}
1144EXPORT_SYMBOL_GPL(thermal_cooling_device_unregister);
1145
1146static void bind_tz(struct thermal_zone_device *tz)
1147{
1148 int ret;
1149 struct thermal_cooling_device *pos = NULL;
1150
1151 if (!tz->ops->bind)
1152 return;
1153
1154 mutex_lock(&thermal_list_lock);
1155
1156 list_for_each_entry(pos, &thermal_cdev_list, node) {
1157 ret = tz->ops->bind(tz, pos);
1158 if (ret)
1159 print_bind_err_msg(tz, cdev: pos, ret);
1160 }
1161
1162 mutex_unlock(lock: &thermal_list_lock);
1163}
1164
1165static void thermal_set_delay_jiffies(unsigned long *delay_jiffies, int delay_ms)
1166{
1167 *delay_jiffies = msecs_to_jiffies(m: delay_ms);
1168 if (delay_ms > 1000)
1169 *delay_jiffies = round_jiffies(j: *delay_jiffies);
1170}
1171
1172int thermal_zone_get_crit_temp(struct thermal_zone_device *tz, int *temp)
1173{
1174 int i, ret = -EINVAL;
1175
1176 if (tz->ops->get_crit_temp)
1177 return tz->ops->get_crit_temp(tz, temp);
1178
1179 if (!tz->trips)
1180 return -EINVAL;
1181
1182 mutex_lock(&tz->lock);
1183
1184 for (i = 0; i < tz->num_trips; i++) {
1185 if (tz->trips[i].type == THERMAL_TRIP_CRITICAL) {
1186 *temp = tz->trips[i].temperature;
1187 ret = 0;
1188 break;
1189 }
1190 }
1191
1192 mutex_unlock(lock: &tz->lock);
1193
1194 return ret;
1195}
1196EXPORT_SYMBOL_GPL(thermal_zone_get_crit_temp);
1197
1198/**
1199 * thermal_zone_device_register_with_trips() - register a new thermal zone device
1200 * @type: the thermal zone device type
1201 * @trips: a pointer to an array of thermal trips
1202 * @num_trips: the number of trip points the thermal zone support
1203 * @mask: a bit string indicating the writeablility of trip points
1204 * @devdata: private device data
1205 * @ops: standard thermal zone device callbacks
1206 * @tzp: thermal zone platform parameters
1207 * @passive_delay: number of milliseconds to wait between polls when
1208 * performing passive cooling
1209 * @polling_delay: number of milliseconds to wait between polls when checking
1210 * whether trip points have been crossed (0 for interrupt
1211 * driven systems)
1212 *
1213 * This interface function adds a new thermal zone device (sensor) to
1214 * /sys/class/thermal folder as thermal_zone[0-*]. It tries to bind all the
1215 * thermal cooling devices registered at the same time.
1216 * thermal_zone_device_unregister() must be called when the device is no
1217 * longer needed. The passive cooling depends on the .get_trend() return value.
1218 *
1219 * Return: a pointer to the created struct thermal_zone_device or an
1220 * in case of error, an ERR_PTR. Caller must check return value with
1221 * IS_ERR*() helpers.
1222 */
1223struct thermal_zone_device *
1224thermal_zone_device_register_with_trips(const char *type, struct thermal_trip *trips, int num_trips, int mask,
1225 void *devdata, struct thermal_zone_device_ops *ops,
1226 const struct thermal_zone_params *tzp, int passive_delay,
1227 int polling_delay)
1228{
1229 struct thermal_zone_device *tz;
1230 int id;
1231 int result;
1232 struct thermal_governor *governor;
1233
1234 if (!type || strlen(type) == 0) {
1235 pr_err("No thermal zone type defined\n");
1236 return ERR_PTR(error: -EINVAL);
1237 }
1238
1239 if (strlen(type) >= THERMAL_NAME_LENGTH) {
1240 pr_err("Thermal zone name (%s) too long, should be under %d chars\n",
1241 type, THERMAL_NAME_LENGTH);
1242 return ERR_PTR(error: -EINVAL);
1243 }
1244
1245 /*
1246 * Max trip count can't exceed 31 as the "mask >> num_trips" condition.
1247 * For example, shifting by 32 will result in compiler warning:
1248 * warning: right shift count >= width of type [-Wshift-count- overflow]
1249 *
1250 * Also "mask >> num_trips" will always be true with 32 bit shift.
1251 * E.g. mask = 0x80000000 for trip id 31 to be RW. Then
1252 * mask >> 32 = 0x80000000
1253 * This will result in failure for the below condition.
1254 *
1255 * Check will be true when the bit 31 of the mask is set.
1256 * 32 bit shift will cause overflow of 4 byte integer.
1257 */
1258 if (num_trips > (BITS_PER_TYPE(int) - 1) || num_trips < 0 || mask >> num_trips) {
1259 pr_err("Incorrect number of thermal trips\n");
1260 return ERR_PTR(error: -EINVAL);
1261 }
1262
1263 if (!ops) {
1264 pr_err("Thermal zone device ops not defined\n");
1265 return ERR_PTR(error: -EINVAL);
1266 }
1267
1268 if (num_trips > 0 && !trips)
1269 return ERR_PTR(error: -EINVAL);
1270
1271 if (!thermal_class)
1272 return ERR_PTR(error: -ENODEV);
1273
1274 tz = kzalloc(size: sizeof(*tz), GFP_KERNEL);
1275 if (!tz)
1276 return ERR_PTR(error: -ENOMEM);
1277
1278 if (tzp) {
1279 tz->tzp = kmemdup(p: tzp, size: sizeof(*tzp), GFP_KERNEL);
1280 if (!tz->tzp) {
1281 result = -ENOMEM;
1282 goto free_tz;
1283 }
1284 }
1285
1286 INIT_LIST_HEAD(list: &tz->thermal_instances);
1287 ida_init(ida: &tz->ida);
1288 mutex_init(&tz->lock);
1289 id = ida_alloc(ida: &thermal_tz_ida, GFP_KERNEL);
1290 if (id < 0) {
1291 result = id;
1292 goto free_tzp;
1293 }
1294
1295 tz->id = id;
1296 strscpy(p: tz->type, q: type, size: sizeof(tz->type));
1297
1298 if (!ops->critical)
1299 ops->critical = thermal_zone_device_critical;
1300
1301 tz->ops = ops;
1302 tz->device.class = thermal_class;
1303 tz->devdata = devdata;
1304 tz->trips = trips;
1305 tz->num_trips = num_trips;
1306
1307 thermal_set_delay_jiffies(delay_jiffies: &tz->passive_delay_jiffies, delay_ms: passive_delay);
1308 thermal_set_delay_jiffies(delay_jiffies: &tz->polling_delay_jiffies, delay_ms: polling_delay);
1309
1310 /* sys I/F */
1311 /* Add nodes that are always present via .groups */
1312 result = thermal_zone_create_device_groups(tz, mask);
1313 if (result)
1314 goto remove_id;
1315
1316 /* A new thermal zone needs to be updated anyway. */
1317 atomic_set(v: &tz->need_update, i: 1);
1318
1319 result = dev_set_name(dev: &tz->device, name: "thermal_zone%d", tz->id);
1320 if (result) {
1321 thermal_zone_destroy_device_groups(tz);
1322 goto remove_id;
1323 }
1324 result = device_register(dev: &tz->device);
1325 if (result)
1326 goto release_device;
1327
1328 /* Update 'this' zone's governor information */
1329 mutex_lock(&thermal_governor_lock);
1330
1331 if (tz->tzp)
1332 governor = __find_governor(name: tz->tzp->governor_name);
1333 else
1334 governor = def_governor;
1335
1336 result = thermal_set_governor(tz, new_gov: governor);
1337 if (result) {
1338 mutex_unlock(lock: &thermal_governor_lock);
1339 goto unregister;
1340 }
1341
1342 mutex_unlock(lock: &thermal_governor_lock);
1343
1344 if (!tz->tzp || !tz->tzp->no_hwmon) {
1345 result = thermal_add_hwmon_sysfs(tz);
1346 if (result)
1347 goto unregister;
1348 }
1349
1350 mutex_lock(&thermal_list_lock);
1351 list_add_tail(new: &tz->node, head: &thermal_tz_list);
1352 mutex_unlock(lock: &thermal_list_lock);
1353
1354 /* Bind cooling devices for this zone */
1355 bind_tz(tz);
1356
1357 INIT_DELAYED_WORK(&tz->poll_queue, thermal_zone_device_check);
1358
1359 thermal_zone_device_init(tz);
1360 /* Update the new thermal zone and mark it as already updated. */
1361 if (atomic_cmpxchg(v: &tz->need_update, old: 1, new: 0))
1362 thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
1363
1364 thermal_notify_tz_create(tz_id: tz->id, name: tz->type);
1365
1366 return tz;
1367
1368unregister:
1369 device_del(dev: &tz->device);
1370release_device:
1371 put_device(dev: &tz->device);
1372 tz = NULL;
1373remove_id:
1374 ida_free(&thermal_tz_ida, id);
1375free_tzp:
1376 kfree(objp: tz->tzp);
1377free_tz:
1378 kfree(objp: tz);
1379 return ERR_PTR(error: result);
1380}
1381EXPORT_SYMBOL_GPL(thermal_zone_device_register_with_trips);
1382
1383struct thermal_zone_device *thermal_tripless_zone_device_register(
1384 const char *type,
1385 void *devdata,
1386 struct thermal_zone_device_ops *ops,
1387 const struct thermal_zone_params *tzp)
1388{
1389 return thermal_zone_device_register_with_trips(type, NULL, 0, 0, devdata,
1390 ops, tzp, 0, 0);
1391}
1392EXPORT_SYMBOL_GPL(thermal_tripless_zone_device_register);
1393
1394void *thermal_zone_device_priv(struct thermal_zone_device *tzd)
1395{
1396 return tzd->devdata;
1397}
1398EXPORT_SYMBOL_GPL(thermal_zone_device_priv);
1399
1400const char *thermal_zone_device_type(struct thermal_zone_device *tzd)
1401{
1402 return tzd->type;
1403}
1404EXPORT_SYMBOL_GPL(thermal_zone_device_type);
1405
1406int thermal_zone_device_id(struct thermal_zone_device *tzd)
1407{
1408 return tzd->id;
1409}
1410EXPORT_SYMBOL_GPL(thermal_zone_device_id);
1411
1412struct device *thermal_zone_device(struct thermal_zone_device *tzd)
1413{
1414 return &tzd->device;
1415}
1416EXPORT_SYMBOL_GPL(thermal_zone_device);
1417
1418/**
1419 * thermal_zone_device_unregister - removes the registered thermal zone device
1420 * @tz: the thermal zone device to remove
1421 */
1422void thermal_zone_device_unregister(struct thermal_zone_device *tz)
1423{
1424 int tz_id;
1425 struct thermal_cooling_device *cdev;
1426 struct thermal_zone_device *pos = NULL;
1427
1428 if (!tz)
1429 return;
1430
1431 tz_id = tz->id;
1432
1433 mutex_lock(&thermal_list_lock);
1434 list_for_each_entry(pos, &thermal_tz_list, node)
1435 if (pos == tz)
1436 break;
1437 if (pos != tz) {
1438 /* thermal zone device not found */
1439 mutex_unlock(lock: &thermal_list_lock);
1440 return;
1441 }
1442 list_del(entry: &tz->node);
1443
1444 /* Unbind all cdevs associated with 'this' thermal zone */
1445 list_for_each_entry(cdev, &thermal_cdev_list, node)
1446 if (tz->ops->unbind)
1447 tz->ops->unbind(tz, cdev);
1448
1449 mutex_unlock(lock: &thermal_list_lock);
1450
1451 cancel_delayed_work_sync(dwork: &tz->poll_queue);
1452
1453 thermal_set_governor(tz, NULL);
1454
1455 thermal_remove_hwmon_sysfs(tz);
1456 ida_free(&thermal_tz_ida, id: tz->id);
1457 ida_destroy(ida: &tz->ida);
1458
1459 mutex_lock(&tz->lock);
1460 device_del(dev: &tz->device);
1461 mutex_unlock(lock: &tz->lock);
1462
1463 kfree(objp: tz->tzp);
1464
1465 put_device(dev: &tz->device);
1466
1467 thermal_notify_tz_delete(tz_id);
1468}
1469EXPORT_SYMBOL_GPL(thermal_zone_device_unregister);
1470
1471/**
1472 * thermal_zone_get_zone_by_name() - search for a zone and returns its ref
1473 * @name: thermal zone name to fetch the temperature
1474 *
1475 * When only one zone is found with the passed name, returns a reference to it.
1476 *
1477 * Return: On success returns a reference to an unique thermal zone with
1478 * matching name equals to @name, an ERR_PTR otherwise (-EINVAL for invalid
1479 * paramenters, -ENODEV for not found and -EEXIST for multiple matches).
1480 */
1481struct thermal_zone_device *thermal_zone_get_zone_by_name(const char *name)
1482{
1483 struct thermal_zone_device *pos = NULL, *ref = ERR_PTR(error: -EINVAL);
1484 unsigned int found = 0;
1485
1486 if (!name)
1487 goto exit;
1488
1489 mutex_lock(&thermal_list_lock);
1490 list_for_each_entry(pos, &thermal_tz_list, node)
1491 if (!strncasecmp(s1: name, s2: pos->type, THERMAL_NAME_LENGTH)) {
1492 found++;
1493 ref = pos;
1494 }
1495 mutex_unlock(lock: &thermal_list_lock);
1496
1497 /* nothing has been found, thus an error code for it */
1498 if (found == 0)
1499 ref = ERR_PTR(error: -ENODEV);
1500 else if (found > 1)
1501 /* Success only when an unique zone is found */
1502 ref = ERR_PTR(error: -EEXIST);
1503
1504exit:
1505 return ref;
1506}
1507EXPORT_SYMBOL_GPL(thermal_zone_get_zone_by_name);
1508
1509static int thermal_pm_notify(struct notifier_block *nb,
1510 unsigned long mode, void *_unused)
1511{
1512 struct thermal_zone_device *tz;
1513
1514 switch (mode) {
1515 case PM_HIBERNATION_PREPARE:
1516 case PM_RESTORE_PREPARE:
1517 case PM_SUSPEND_PREPARE:
1518 atomic_set(v: &in_suspend, i: 1);
1519 break;
1520 case PM_POST_HIBERNATION:
1521 case PM_POST_RESTORE:
1522 case PM_POST_SUSPEND:
1523 atomic_set(v: &in_suspend, i: 0);
1524 list_for_each_entry(tz, &thermal_tz_list, node) {
1525 thermal_zone_device_init(tz);
1526 thermal_zone_device_update(tz,
1527 THERMAL_EVENT_UNSPECIFIED);
1528 }
1529 break;
1530 default:
1531 break;
1532 }
1533 return 0;
1534}
1535
1536static struct notifier_block thermal_pm_nb = {
1537 .notifier_call = thermal_pm_notify,
1538};
1539
1540static int __init thermal_init(void)
1541{
1542 int result;
1543
1544 result = thermal_netlink_init();
1545 if (result)
1546 goto error;
1547
1548 result = thermal_register_governors();
1549 if (result)
1550 goto unregister_netlink;
1551
1552 thermal_class = kzalloc(size: sizeof(*thermal_class), GFP_KERNEL);
1553 if (!thermal_class) {
1554 result = -ENOMEM;
1555 goto unregister_governors;
1556 }
1557
1558 thermal_class->name = "thermal";
1559 thermal_class->dev_release = thermal_release;
1560
1561 result = class_register(class: thermal_class);
1562 if (result) {
1563 kfree(objp: thermal_class);
1564 thermal_class = NULL;
1565 goto unregister_governors;
1566 }
1567
1568 result = register_pm_notifier(nb: &thermal_pm_nb);
1569 if (result)
1570 pr_warn("Thermal: Can not register suspend notifier, return %d\n",
1571 result);
1572
1573 return 0;
1574
1575unregister_governors:
1576 thermal_unregister_governors();
1577unregister_netlink:
1578 thermal_netlink_exit();
1579error:
1580 mutex_destroy(lock: &thermal_list_lock);
1581 mutex_destroy(lock: &thermal_governor_lock);
1582 return result;
1583}
1584postcore_initcall(thermal_init);
1585

source code of linux/drivers/thermal/thermal_core.c