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1 /*
2  *  thermal.c - Generic Thermal Management Sysfs support.
3  *
4  *  Copyright (C) 2008 Intel Corp
5  *  Copyright (C) 2008 Zhang Rui <rui.zhang@intel.com>
6  *  Copyright (C) 2008 Sujith Thomas <sujith.thomas@intel.com>
7  *
8  *  This program is free software; you can redistribute it and/or modify
9  *  it under the terms of the GNU General Public License as published by
10  *  the Free Software Foundation; version 2 of the License.
11  */
12 
13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14 
15 #include <linux/module.h>
16 #include <linux/device.h>
17 #include <linux/err.h>
18 #include <linux/slab.h>
19 #include <linux/kdev_t.h>
20 #include <linux/idr.h>
21 #include <linux/thermal.h>
22 #include <linux/reboot.h>
23 #include <linux/string.h>
24 #include <linux/of.h>
25 #include <net/netlink.h>
26 #include <net/genetlink.h>
27 #include <linux/suspend.h>
28 
29 #define CREATE_TRACE_POINTS
30 #include <trace/events/thermal.h>
31 
32 #include "thermal_core.h"
33 #include "thermal_hwmon.h"
34 
35 MODULE_AUTHOR("Zhang Rui");
36 MODULE_DESCRIPTION("Generic thermal management sysfs support");
37 MODULE_LICENSE("GPL v2");
38 
39 static DEFINE_IDA(thermal_tz_ida);
40 static DEFINE_IDA(thermal_cdev_ida);
41 
42 static LIST_HEAD(thermal_tz_list);
43 static LIST_HEAD(thermal_cdev_list);
44 static LIST_HEAD(thermal_governor_list);
45 
46 static DEFINE_MUTEX(thermal_list_lock);
47 static DEFINE_MUTEX(thermal_governor_lock);
48 static DEFINE_MUTEX(poweroff_lock);
49 
50 static atomic_t in_suspend;
51 static bool power_off_triggered;
52 
53 static struct thermal_governor *def_governor;
54 
55 /*
56  * Governor section: set of functions to handle thermal governors
57  *
58  * Functions to help in the life cycle of thermal governors within
59  * the thermal core and by the thermal governor code.
60  */
61 
__find_governor(const char * name)62 static struct thermal_governor *__find_governor(const char *name)
63 {
64 	struct thermal_governor *pos;
65 
66 	if (!name || !name[0])
67 		return def_governor;
68 
69 	list_for_each_entry(pos, &thermal_governor_list, governor_list)
70 		if (!strncasecmp(name, pos->name, THERMAL_NAME_LENGTH))
71 			return pos;
72 
73 	return NULL;
74 }
75 
76 /**
77  * bind_previous_governor() - bind the previous governor of the thermal zone
78  * @tz:		a valid pointer to a struct thermal_zone_device
79  * @failed_gov_name:	the name of the governor that failed to register
80  *
81  * Register the previous governor of the thermal zone after a new
82  * governor has failed to be bound.
83  */
bind_previous_governor(struct thermal_zone_device * tz,const char * failed_gov_name)84 static void bind_previous_governor(struct thermal_zone_device *tz,
85 				   const char *failed_gov_name)
86 {
87 	if (tz->governor && tz->governor->bind_to_tz) {
88 		if (tz->governor->bind_to_tz(tz)) {
89 			dev_err(&tz->device,
90 				"governor %s failed to bind and the previous one (%s) failed to bind again, thermal zone %s has no governor\n",
91 				failed_gov_name, tz->governor->name, tz->type);
92 			tz->governor = NULL;
93 		}
94 	}
95 }
96 
97 /**
98  * thermal_set_governor() - Switch to another governor
99  * @tz:		a valid pointer to a struct thermal_zone_device
100  * @new_gov:	pointer to the new governor
101  *
102  * Change the governor of thermal zone @tz.
103  *
104  * Return: 0 on success, an error if the new governor's bind_to_tz() failed.
105  */
thermal_set_governor(struct thermal_zone_device * tz,struct thermal_governor * new_gov)106 static int thermal_set_governor(struct thermal_zone_device *tz,
107 				struct thermal_governor *new_gov)
108 {
109 	int ret = 0;
110 
111 	if (tz->governor && tz->governor->unbind_from_tz)
112 		tz->governor->unbind_from_tz(tz);
113 
114 	if (new_gov && new_gov->bind_to_tz) {
115 		ret = new_gov->bind_to_tz(tz);
116 		if (ret) {
117 			bind_previous_governor(tz, new_gov->name);
118 
119 			return ret;
120 		}
121 	}
122 
123 	tz->governor = new_gov;
124 
125 	return ret;
126 }
127 
thermal_register_governor(struct thermal_governor * governor)128 int thermal_register_governor(struct thermal_governor *governor)
129 {
130 	int err;
131 	const char *name;
132 	struct thermal_zone_device *pos;
133 
134 	if (!governor)
135 		return -EINVAL;
136 
137 	mutex_lock(&thermal_governor_lock);
138 
139 	err = -EBUSY;
140 	if (!__find_governor(governor->name)) {
141 		bool match_default;
142 
143 		err = 0;
144 		list_add(&governor->governor_list, &thermal_governor_list);
145 		match_default = !strncmp(governor->name,
146 					 DEFAULT_THERMAL_GOVERNOR,
147 					 THERMAL_NAME_LENGTH);
148 
149 		if (!def_governor && match_default)
150 			def_governor = governor;
151 	}
152 
153 	mutex_lock(&thermal_list_lock);
154 
155 	list_for_each_entry(pos, &thermal_tz_list, node) {
156 		/*
157 		 * only thermal zones with specified tz->tzp->governor_name
158 		 * may run with tz->govenor unset
159 		 */
160 		if (pos->governor)
161 			continue;
162 
163 		name = pos->tzp->governor_name;
164 
165 		if (!strncasecmp(name, governor->name, THERMAL_NAME_LENGTH)) {
166 			int ret;
167 
168 			ret = thermal_set_governor(pos, governor);
169 			if (ret)
170 				dev_err(&pos->device,
171 					"Failed to set governor %s for thermal zone %s: %d\n",
172 					governor->name, pos->type, ret);
173 		}
174 	}
175 
176 	mutex_unlock(&thermal_list_lock);
177 	mutex_unlock(&thermal_governor_lock);
178 
179 	return err;
180 }
181 
thermal_unregister_governor(struct thermal_governor * governor)182 void thermal_unregister_governor(struct thermal_governor *governor)
183 {
184 	struct thermal_zone_device *pos;
185 
186 	if (!governor)
187 		return;
188 
189 	mutex_lock(&thermal_governor_lock);
190 
191 	if (!__find_governor(governor->name))
192 		goto exit;
193 
194 	mutex_lock(&thermal_list_lock);
195 
196 	list_for_each_entry(pos, &thermal_tz_list, node) {
197 		if (!strncasecmp(pos->governor->name, governor->name,
198 				 THERMAL_NAME_LENGTH))
199 			thermal_set_governor(pos, NULL);
200 	}
201 
202 	mutex_unlock(&thermal_list_lock);
203 	list_del(&governor->governor_list);
204 exit:
205 	mutex_unlock(&thermal_governor_lock);
206 }
207 
thermal_zone_device_set_policy(struct thermal_zone_device * tz,char * policy)208 int thermal_zone_device_set_policy(struct thermal_zone_device *tz,
209 				   char *policy)
210 {
211 	struct thermal_governor *gov;
212 	int ret = -EINVAL;
213 
214 	mutex_lock(&thermal_governor_lock);
215 	mutex_lock(&tz->lock);
216 
217 	gov = __find_governor(strim(policy));
218 	if (!gov)
219 		goto exit;
220 
221 	ret = thermal_set_governor(tz, gov);
222 
223 exit:
224 	mutex_unlock(&tz->lock);
225 	mutex_unlock(&thermal_governor_lock);
226 
227 	return ret;
228 }
229 
thermal_build_list_of_policies(char * buf)230 int thermal_build_list_of_policies(char *buf)
231 {
232 	struct thermal_governor *pos;
233 	ssize_t count = 0;
234 	ssize_t size = PAGE_SIZE;
235 
236 	mutex_lock(&thermal_governor_lock);
237 
238 	list_for_each_entry(pos, &thermal_governor_list, governor_list) {
239 		size = PAGE_SIZE - count;
240 		count += scnprintf(buf + count, size, "%s ", pos->name);
241 	}
242 	count += scnprintf(buf + count, size, "\n");
243 
244 	mutex_unlock(&thermal_governor_lock);
245 
246 	return count;
247 }
248 
thermal_register_governors(void)249 static int __init thermal_register_governors(void)
250 {
251 	int result;
252 
253 	result = thermal_gov_step_wise_register();
254 	if (result)
255 		return result;
256 
257 	result = thermal_gov_fair_share_register();
258 	if (result)
259 		return result;
260 
261 	result = thermal_gov_bang_bang_register();
262 	if (result)
263 		return result;
264 
265 	result = thermal_gov_user_space_register();
266 	if (result)
267 		return result;
268 
269 	return thermal_gov_power_allocator_register();
270 }
271 
thermal_unregister_governors(void)272 static void thermal_unregister_governors(void)
273 {
274 	thermal_gov_step_wise_unregister();
275 	thermal_gov_fair_share_unregister();
276 	thermal_gov_bang_bang_unregister();
277 	thermal_gov_user_space_unregister();
278 	thermal_gov_power_allocator_unregister();
279 }
280 
281 /*
282  * Zone update section: main control loop applied to each zone while monitoring
283  *
284  * in polling mode. The monitoring is done using a workqueue.
285  * Same update may be done on a zone by calling thermal_zone_device_update().
286  *
287  * An update means:
288  * - Non-critical trips will invoke the governor responsible for that zone;
289  * - Hot trips will produce a notification to userspace;
290  * - Critical trip point will cause a system shutdown.
291  */
thermal_zone_device_set_polling(struct thermal_zone_device * tz,int delay)292 static void thermal_zone_device_set_polling(struct thermal_zone_device *tz,
293 					    int delay)
294 {
295 	if (delay > 1000)
296 		mod_delayed_work(system_freezable_wq, &tz->poll_queue,
297 				 round_jiffies(msecs_to_jiffies(delay)));
298 	else if (delay)
299 		mod_delayed_work(system_freezable_wq, &tz->poll_queue,
300 				 msecs_to_jiffies(delay));
301 	else
302 		cancel_delayed_work(&tz->poll_queue);
303 }
304 
monitor_thermal_zone(struct thermal_zone_device * tz)305 static void monitor_thermal_zone(struct thermal_zone_device *tz)
306 {
307 	mutex_lock(&tz->lock);
308 
309 	if (tz->passive)
310 		thermal_zone_device_set_polling(tz, tz->passive_delay);
311 	else if (tz->polling_delay)
312 		thermal_zone_device_set_polling(tz, tz->polling_delay);
313 	else
314 		thermal_zone_device_set_polling(tz, 0);
315 
316 	mutex_unlock(&tz->lock);
317 }
318 
handle_non_critical_trips(struct thermal_zone_device * tz,int trip,enum thermal_trip_type trip_type)319 static void handle_non_critical_trips(struct thermal_zone_device *tz,
320 				      int trip,
321 				      enum thermal_trip_type trip_type)
322 {
323 	tz->governor ? tz->governor->throttle(tz, trip) :
324 		       def_governor->throttle(tz, trip);
325 }
326 
327 /**
328  * thermal_emergency_poweroff_func - emergency poweroff work after a known delay
329  * @work: work_struct associated with the emergency poweroff function
330  *
331  * This function is called in very critical situations to force
332  * a kernel poweroff after a configurable timeout value.
333  */
thermal_emergency_poweroff_func(struct work_struct * work)334 static void thermal_emergency_poweroff_func(struct work_struct *work)
335 {
336 	/*
337 	 * We have reached here after the emergency thermal shutdown
338 	 * Waiting period has expired. This means orderly_poweroff has
339 	 * not been able to shut off the system for some reason.
340 	 * Try to shut down the system immediately using kernel_power_off
341 	 * if populated
342 	 */
343 	WARN(1, "Attempting kernel_power_off: Temperature too high\n");
344 	kernel_power_off();
345 
346 	/*
347 	 * Worst of the worst case trigger emergency restart
348 	 */
349 	WARN(1, "Attempting emergency_restart: Temperature too high\n");
350 	emergency_restart();
351 }
352 
353 static DECLARE_DELAYED_WORK(thermal_emergency_poweroff_work,
354 			    thermal_emergency_poweroff_func);
355 
356 /**
357  * thermal_emergency_poweroff - Trigger an emergency system poweroff
358  *
359  * This may be called from any critical situation to trigger a system shutdown
360  * after a known period of time. By default this is not scheduled.
361  */
thermal_emergency_poweroff(void)362 static void thermal_emergency_poweroff(void)
363 {
364 	int poweroff_delay_ms = CONFIG_THERMAL_EMERGENCY_POWEROFF_DELAY_MS;
365 	/*
366 	 * poweroff_delay_ms must be a carefully profiled positive value.
367 	 * Its a must for thermal_emergency_poweroff_work to be scheduled
368 	 */
369 	if (poweroff_delay_ms <= 0)
370 		return;
371 	schedule_delayed_work(&thermal_emergency_poweroff_work,
372 			      msecs_to_jiffies(poweroff_delay_ms));
373 }
374 
handle_critical_trips(struct thermal_zone_device * tz,int trip,enum thermal_trip_type trip_type)375 static void handle_critical_trips(struct thermal_zone_device *tz,
376 				  int trip, enum thermal_trip_type trip_type)
377 {
378 	int trip_temp;
379 
380 	tz->ops->get_trip_temp(tz, trip, &trip_temp);
381 
382 	/* If we have not crossed the trip_temp, we do not care. */
383 	if (trip_temp <= 0 || tz->temperature < trip_temp)
384 		return;
385 
386 	trace_thermal_zone_trip(tz, trip, trip_type);
387 
388 	if (tz->ops->notify)
389 		tz->ops->notify(tz, trip, trip_type);
390 
391 	if (trip_type == THERMAL_TRIP_CRITICAL) {
392 		dev_emerg(&tz->device,
393 			  "critical temperature reached (%d C), shutting down\n",
394 			  tz->temperature / 1000);
395 		mutex_lock(&poweroff_lock);
396 		if (!power_off_triggered) {
397 			/*
398 			 * Queue a backup emergency shutdown in the event of
399 			 * orderly_poweroff failure
400 			 */
401 			thermal_emergency_poweroff();
402 			orderly_poweroff(true);
403 			power_off_triggered = true;
404 		}
405 		mutex_unlock(&poweroff_lock);
406 	}
407 }
408 
handle_thermal_trip(struct thermal_zone_device * tz,int trip)409 static void handle_thermal_trip(struct thermal_zone_device *tz, int trip)
410 {
411 	enum thermal_trip_type type;
412 
413 	/* Ignore disabled trip points */
414 	if (test_bit(trip, &tz->trips_disabled))
415 		return;
416 
417 	tz->ops->get_trip_type(tz, trip, &type);
418 
419 	if (type == THERMAL_TRIP_CRITICAL || type == THERMAL_TRIP_HOT)
420 		handle_critical_trips(tz, trip, type);
421 	else
422 		handle_non_critical_trips(tz, trip, type);
423 	/*
424 	 * Alright, we handled this trip successfully.
425 	 * So, start monitoring again.
426 	 */
427 	monitor_thermal_zone(tz);
428 }
429 
update_temperature(struct thermal_zone_device * tz)430 static void update_temperature(struct thermal_zone_device *tz)
431 {
432 	int temp, ret;
433 
434 	ret = thermal_zone_get_temp(tz, &temp);
435 	if (ret) {
436 		if (ret != -EAGAIN)
437 			dev_warn(&tz->device,
438 				 "failed to read out thermal zone (%d)\n",
439 				 ret);
440 		return;
441 	}
442 
443 	mutex_lock(&tz->lock);
444 	tz->last_temperature = tz->temperature;
445 	tz->temperature = temp;
446 	mutex_unlock(&tz->lock);
447 
448 	trace_thermal_temperature(tz);
449 	if (tz->last_temperature == THERMAL_TEMP_INVALID)
450 		dev_dbg(&tz->device, "last_temperature N/A, current_temperature=%d\n",
451 			tz->temperature);
452 	else
453 		dev_dbg(&tz->device, "last_temperature=%d, current_temperature=%d\n",
454 			tz->last_temperature, tz->temperature);
455 }
456 
thermal_zone_device_init(struct thermal_zone_device * tz)457 static void thermal_zone_device_init(struct thermal_zone_device *tz)
458 {
459 	struct thermal_instance *pos;
460 	tz->temperature = THERMAL_TEMP_INVALID;
461 	list_for_each_entry(pos, &tz->thermal_instances, tz_node)
462 		pos->initialized = false;
463 }
464 
thermal_zone_device_reset(struct thermal_zone_device * tz)465 static void thermal_zone_device_reset(struct thermal_zone_device *tz)
466 {
467 	tz->passive = 0;
468 	thermal_zone_device_init(tz);
469 }
470 
thermal_zone_device_update(struct thermal_zone_device * tz,enum thermal_notify_event event)471 void thermal_zone_device_update(struct thermal_zone_device *tz,
472 				enum thermal_notify_event event)
473 {
474 	int count;
475 
476 	if (atomic_read(&in_suspend))
477 		return;
478 
479 	if (!tz->ops->get_temp)
480 		return;
481 
482 	update_temperature(tz);
483 
484 	thermal_zone_set_trips(tz);
485 
486 	tz->notify_event = event;
487 
488 	for (count = 0; count < tz->trips; count++)
489 		handle_thermal_trip(tz, count);
490 }
491 EXPORT_SYMBOL_GPL(thermal_zone_device_update);
492 
493 /**
494  * thermal_notify_framework - Sensor drivers use this API to notify framework
495  * @tz:		thermal zone device
496  * @trip:	indicates which trip point has been crossed
497  *
498  * This function handles the trip events from sensor drivers. It starts
499  * throttling the cooling devices according to the policy configured.
500  * For CRITICAL and HOT trip points, this notifies the respective drivers,
501  * and does actual throttling for other trip points i.e ACTIVE and PASSIVE.
502  * The throttling policy is based on the configured platform data; if no
503  * platform data is provided, this uses the step_wise throttling policy.
504  */
thermal_notify_framework(struct thermal_zone_device * tz,int trip)505 void thermal_notify_framework(struct thermal_zone_device *tz, int trip)
506 {
507 	handle_thermal_trip(tz, trip);
508 }
509 EXPORT_SYMBOL_GPL(thermal_notify_framework);
510 
thermal_zone_device_check(struct work_struct * work)511 static void thermal_zone_device_check(struct work_struct *work)
512 {
513 	struct thermal_zone_device *tz = container_of(work, struct
514 						      thermal_zone_device,
515 						      poll_queue.work);
516 	thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
517 }
518 
519 /*
520  * Power actor section: interface to power actors to estimate power
521  *
522  * Set of functions used to interact to cooling devices that know
523  * how to estimate their devices power consumption.
524  */
525 
526 /**
527  * power_actor_get_max_power() - get the maximum power that a cdev can consume
528  * @cdev:	pointer to &thermal_cooling_device
529  * @tz:		a valid thermal zone device pointer
530  * @max_power:	pointer in which to store the maximum power
531  *
532  * Calculate the maximum power consumption in milliwats that the
533  * cooling device can currently consume and store it in @max_power.
534  *
535  * Return: 0 on success, -EINVAL if @cdev doesn't support the
536  * power_actor API or -E* on other error.
537  */
power_actor_get_max_power(struct thermal_cooling_device * cdev,struct thermal_zone_device * tz,u32 * max_power)538 int power_actor_get_max_power(struct thermal_cooling_device *cdev,
539 			      struct thermal_zone_device *tz, u32 *max_power)
540 {
541 	if (!cdev_is_power_actor(cdev))
542 		return -EINVAL;
543 
544 	return cdev->ops->state2power(cdev, tz, 0, max_power);
545 }
546 
547 /**
548  * power_actor_get_min_power() - get the mainimum power that a cdev can consume
549  * @cdev:	pointer to &thermal_cooling_device
550  * @tz:		a valid thermal zone device pointer
551  * @min_power:	pointer in which to store the minimum power
552  *
553  * Calculate the minimum power consumption in milliwatts that the
554  * cooling device can currently consume and store it in @min_power.
555  *
556  * Return: 0 on success, -EINVAL if @cdev doesn't support the
557  * power_actor API or -E* on other error.
558  */
power_actor_get_min_power(struct thermal_cooling_device * cdev,struct thermal_zone_device * tz,u32 * min_power)559 int power_actor_get_min_power(struct thermal_cooling_device *cdev,
560 			      struct thermal_zone_device *tz, u32 *min_power)
561 {
562 	unsigned long max_state;
563 	int ret;
564 
565 	if (!cdev_is_power_actor(cdev))
566 		return -EINVAL;
567 
568 	ret = cdev->ops->get_max_state(cdev, &max_state);
569 	if (ret)
570 		return ret;
571 
572 	return cdev->ops->state2power(cdev, tz, max_state, min_power);
573 }
574 
575 /**
576  * power_actor_set_power() - limit the maximum power a cooling device consumes
577  * @cdev:	pointer to &thermal_cooling_device
578  * @instance:	thermal instance to update
579  * @power:	the power in milliwatts
580  *
581  * Set the cooling device to consume at most @power milliwatts. The limit is
582  * expected to be a cap at the maximum power consumption.
583  *
584  * Return: 0 on success, -EINVAL if the cooling device does not
585  * implement the power actor API or -E* for other failures.
586  */
power_actor_set_power(struct thermal_cooling_device * cdev,struct thermal_instance * instance,u32 power)587 int power_actor_set_power(struct thermal_cooling_device *cdev,
588 			  struct thermal_instance *instance, u32 power)
589 {
590 	unsigned long state;
591 	int ret;
592 
593 	if (!cdev_is_power_actor(cdev))
594 		return -EINVAL;
595 
596 	ret = cdev->ops->power2state(cdev, instance->tz, power, &state);
597 	if (ret)
598 		return ret;
599 
600 	instance->target = state;
601 	mutex_lock(&cdev->lock);
602 	cdev->updated = false;
603 	mutex_unlock(&cdev->lock);
604 	thermal_cdev_update(cdev);
605 
606 	return 0;
607 }
608 
thermal_zone_device_rebind_exception(struct thermal_zone_device * tz,const char * cdev_type,size_t size)609 void thermal_zone_device_rebind_exception(struct thermal_zone_device *tz,
610 					  const char *cdev_type, size_t size)
611 {
612 	struct thermal_cooling_device *cdev = NULL;
613 
614 	mutex_lock(&thermal_list_lock);
615 	list_for_each_entry(cdev, &thermal_cdev_list, node) {
616 		/* skip non matching cdevs */
617 		if (strncmp(cdev_type, cdev->type, size))
618 			continue;
619 
620 		/* re binding the exception matching the type pattern */
621 		thermal_zone_bind_cooling_device(tz, THERMAL_TRIPS_NONE, cdev,
622 						 THERMAL_NO_LIMIT,
623 						 THERMAL_NO_LIMIT,
624 						 THERMAL_WEIGHT_DEFAULT);
625 	}
626 	mutex_unlock(&thermal_list_lock);
627 }
628 
thermal_zone_device_unbind_exception(struct thermal_zone_device * tz,const char * cdev_type,size_t size)629 void thermal_zone_device_unbind_exception(struct thermal_zone_device *tz,
630 					  const char *cdev_type, size_t size)
631 {
632 	struct thermal_cooling_device *cdev = NULL;
633 
634 	mutex_lock(&thermal_list_lock);
635 	list_for_each_entry(cdev, &thermal_cdev_list, node) {
636 		/* skip non matching cdevs */
637 		if (strncmp(cdev_type, cdev->type, size))
638 			continue;
639 		/* unbinding the exception matching the type pattern */
640 		thermal_zone_unbind_cooling_device(tz, THERMAL_TRIPS_NONE,
641 						   cdev);
642 	}
643 	mutex_unlock(&thermal_list_lock);
644 }
645 
646 /*
647  * Device management section: cooling devices, zones devices, and binding
648  *
649  * Set of functions provided by the thermal core for:
650  * - cooling devices lifecycle: registration, unregistration,
651  *				binding, and unbinding.
652  * - thermal zone devices lifecycle: registration, unregistration,
653  *				     binding, and unbinding.
654  */
655 
656 /**
657  * thermal_zone_bind_cooling_device() - bind a cooling device to a thermal zone
658  * @tz:		pointer to struct thermal_zone_device
659  * @trip:	indicates which trip point the cooling devices is
660  *		associated with in this thermal zone.
661  * @cdev:	pointer to struct thermal_cooling_device
662  * @upper:	the Maximum cooling state for this trip point.
663  *		THERMAL_NO_LIMIT means no upper limit,
664  *		and the cooling device can be in max_state.
665  * @lower:	the Minimum cooling state can be used for this trip point.
666  *		THERMAL_NO_LIMIT means no lower limit,
667  *		and the cooling device can be in cooling state 0.
668  * @weight:	The weight of the cooling device to be bound to the
669  *		thermal zone. Use THERMAL_WEIGHT_DEFAULT for the
670  *		default value
671  *
672  * This interface function bind a thermal cooling device to the certain trip
673  * point of a thermal zone device.
674  * This function is usually called in the thermal zone device .bind callback.
675  *
676  * Return: 0 on success, the proper error value otherwise.
677  */
thermal_zone_bind_cooling_device(struct thermal_zone_device * tz,int trip,struct thermal_cooling_device * cdev,unsigned long upper,unsigned long lower,unsigned int weight)678 int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz,
679 				     int trip,
680 				     struct thermal_cooling_device *cdev,
681 				     unsigned long upper, unsigned long lower,
682 				     unsigned int weight)
683 {
684 	struct thermal_instance *dev;
685 	struct thermal_instance *pos;
686 	struct thermal_zone_device *pos1;
687 	struct thermal_cooling_device *pos2;
688 	unsigned long max_state;
689 	int result, ret;
690 
691 	if (trip >= tz->trips || (trip < 0 && trip != THERMAL_TRIPS_NONE))
692 		return -EINVAL;
693 
694 	list_for_each_entry(pos1, &thermal_tz_list, node) {
695 		if (pos1 == tz)
696 			break;
697 	}
698 	list_for_each_entry(pos2, &thermal_cdev_list, node) {
699 		if (pos2 == cdev)
700 			break;
701 	}
702 
703 	if (tz != pos1 || cdev != pos2)
704 		return -EINVAL;
705 
706 	ret = cdev->ops->get_max_state(cdev, &max_state);
707 	if (ret)
708 		return ret;
709 
710 	/* lower default 0, upper default max_state */
711 	lower = lower == THERMAL_NO_LIMIT ? 0 : lower;
712 	upper = upper == THERMAL_NO_LIMIT ? max_state : upper;
713 
714 	if (lower > upper || upper > max_state)
715 		return -EINVAL;
716 
717 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
718 	if (!dev)
719 		return -ENOMEM;
720 	dev->tz = tz;
721 	dev->cdev = cdev;
722 	dev->trip = trip;
723 	dev->upper = upper;
724 	dev->lower = lower;
725 	dev->target = THERMAL_NO_TARGET;
726 	dev->weight = weight;
727 
728 	result = ida_simple_get(&tz->ida, 0, 0, GFP_KERNEL);
729 	if (result < 0)
730 		goto free_mem;
731 
732 	dev->id = result;
733 	sprintf(dev->name, "cdev%d", dev->id);
734 	result =
735 	    sysfs_create_link(&tz->device.kobj, &cdev->device.kobj, dev->name);
736 	if (result)
737 		goto release_ida;
738 
739 	sprintf(dev->attr_name, "cdev%d_trip_point", dev->id);
740 	sysfs_attr_init(&dev->attr.attr);
741 	dev->attr.attr.name = dev->attr_name;
742 	dev->attr.attr.mode = 0444;
743 	dev->attr.show = thermal_cooling_device_trip_point_show;
744 	result = device_create_file(&tz->device, &dev->attr);
745 	if (result)
746 		goto remove_symbol_link;
747 
748 	sprintf(dev->weight_attr_name, "cdev%d_weight", dev->id);
749 	sysfs_attr_init(&dev->weight_attr.attr);
750 	dev->weight_attr.attr.name = dev->weight_attr_name;
751 	dev->weight_attr.attr.mode = S_IWUSR | S_IRUGO;
752 	dev->weight_attr.show = thermal_cooling_device_weight_show;
753 	dev->weight_attr.store = thermal_cooling_device_weight_store;
754 	result = device_create_file(&tz->device, &dev->weight_attr);
755 	if (result)
756 		goto remove_trip_file;
757 
758 	mutex_lock(&tz->lock);
759 	mutex_lock(&cdev->lock);
760 	list_for_each_entry(pos, &tz->thermal_instances, tz_node)
761 		if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
762 			result = -EEXIST;
763 			break;
764 		}
765 	if (!result) {
766 		list_add_tail(&dev->tz_node, &tz->thermal_instances);
767 		list_add_tail(&dev->cdev_node, &cdev->thermal_instances);
768 		atomic_set(&tz->need_update, 1);
769 	}
770 	mutex_unlock(&cdev->lock);
771 	mutex_unlock(&tz->lock);
772 
773 	if (!result)
774 		return 0;
775 
776 	device_remove_file(&tz->device, &dev->weight_attr);
777 remove_trip_file:
778 	device_remove_file(&tz->device, &dev->attr);
779 remove_symbol_link:
780 	sysfs_remove_link(&tz->device.kobj, dev->name);
781 release_ida:
782 	ida_simple_remove(&tz->ida, dev->id);
783 free_mem:
784 	kfree(dev);
785 	return result;
786 }
787 EXPORT_SYMBOL_GPL(thermal_zone_bind_cooling_device);
788 
789 /**
790  * thermal_zone_unbind_cooling_device() - unbind a cooling device from a
791  *					  thermal zone.
792  * @tz:		pointer to a struct thermal_zone_device.
793  * @trip:	indicates which trip point the cooling devices is
794  *		associated with in this thermal zone.
795  * @cdev:	pointer to a struct thermal_cooling_device.
796  *
797  * This interface function unbind a thermal cooling device from the certain
798  * trip point of a thermal zone device.
799  * This function is usually called in the thermal zone device .unbind callback.
800  *
801  * Return: 0 on success, the proper error value otherwise.
802  */
thermal_zone_unbind_cooling_device(struct thermal_zone_device * tz,int trip,struct thermal_cooling_device * cdev)803 int thermal_zone_unbind_cooling_device(struct thermal_zone_device *tz,
804 				       int trip,
805 				       struct thermal_cooling_device *cdev)
806 {
807 	struct thermal_instance *pos, *next;
808 
809 	mutex_lock(&tz->lock);
810 	mutex_lock(&cdev->lock);
811 	list_for_each_entry_safe(pos, next, &tz->thermal_instances, tz_node) {
812 		if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
813 			list_del(&pos->tz_node);
814 			list_del(&pos->cdev_node);
815 			mutex_unlock(&cdev->lock);
816 			mutex_unlock(&tz->lock);
817 			goto unbind;
818 		}
819 	}
820 	mutex_unlock(&cdev->lock);
821 	mutex_unlock(&tz->lock);
822 
823 	return -ENODEV;
824 
825 unbind:
826 	device_remove_file(&tz->device, &pos->weight_attr);
827 	device_remove_file(&tz->device, &pos->attr);
828 	sysfs_remove_link(&tz->device.kobj, pos->name);
829 	ida_simple_remove(&tz->ida, pos->id);
830 	kfree(pos);
831 	return 0;
832 }
833 EXPORT_SYMBOL_GPL(thermal_zone_unbind_cooling_device);
834 
thermal_release(struct device * dev)835 static void thermal_release(struct device *dev)
836 {
837 	struct thermal_zone_device *tz;
838 	struct thermal_cooling_device *cdev;
839 
840 	if (!strncmp(dev_name(dev), "thermal_zone",
841 		     sizeof("thermal_zone") - 1)) {
842 		tz = to_thermal_zone(dev);
843 		thermal_zone_destroy_device_groups(tz);
844 		kfree(tz);
845 	} else if (!strncmp(dev_name(dev), "cooling_device",
846 			    sizeof("cooling_device") - 1)) {
847 		cdev = to_cooling_device(dev);
848 		kfree(cdev);
849 	}
850 }
851 
852 static struct class thermal_class = {
853 	.name = "thermal",
854 	.dev_release = thermal_release,
855 };
856 
857 static inline
print_bind_err_msg(struct thermal_zone_device * tz,struct thermal_cooling_device * cdev,int ret)858 void print_bind_err_msg(struct thermal_zone_device *tz,
859 			struct thermal_cooling_device *cdev, int ret)
860 {
861 	dev_err(&tz->device, "binding zone %s with cdev %s failed:%d\n",
862 		tz->type, cdev->type, ret);
863 }
864 
__bind(struct thermal_zone_device * tz,int mask,struct thermal_cooling_device * cdev,unsigned long * limits,unsigned int weight)865 static void __bind(struct thermal_zone_device *tz, int mask,
866 		   struct thermal_cooling_device *cdev,
867 		   unsigned long *limits,
868 		   unsigned int weight)
869 {
870 	int i, ret;
871 
872 	for (i = 0; i < tz->trips; i++) {
873 		if (mask & (1 << i)) {
874 			unsigned long upper, lower;
875 
876 			upper = THERMAL_NO_LIMIT;
877 			lower = THERMAL_NO_LIMIT;
878 			if (limits) {
879 				lower = limits[i * 2];
880 				upper = limits[i * 2 + 1];
881 			}
882 			ret = thermal_zone_bind_cooling_device(tz, i, cdev,
883 							       upper, lower,
884 							       weight);
885 			if (ret)
886 				print_bind_err_msg(tz, cdev, ret);
887 		}
888 	}
889 }
890 
bind_cdev(struct thermal_cooling_device * cdev)891 static void bind_cdev(struct thermal_cooling_device *cdev)
892 {
893 	int i, ret;
894 	const struct thermal_zone_params *tzp;
895 	struct thermal_zone_device *pos = NULL;
896 
897 	mutex_lock(&thermal_list_lock);
898 
899 	list_for_each_entry(pos, &thermal_tz_list, node) {
900 		if (!pos->tzp && !pos->ops->bind)
901 			continue;
902 
903 		if (pos->ops->bind) {
904 			ret = pos->ops->bind(pos, cdev);
905 			if (ret)
906 				print_bind_err_msg(pos, cdev, ret);
907 			continue;
908 		}
909 
910 		tzp = pos->tzp;
911 		if (!tzp || !tzp->tbp)
912 			continue;
913 
914 		for (i = 0; i < tzp->num_tbps; i++) {
915 			if (tzp->tbp[i].cdev || !tzp->tbp[i].match)
916 				continue;
917 			if (tzp->tbp[i].match(pos, cdev))
918 				continue;
919 			tzp->tbp[i].cdev = cdev;
920 			__bind(pos, tzp->tbp[i].trip_mask, cdev,
921 			       tzp->tbp[i].binding_limits,
922 			       tzp->tbp[i].weight);
923 		}
924 	}
925 
926 	mutex_unlock(&thermal_list_lock);
927 }
928 
929 /**
930  * __thermal_cooling_device_register() - register a new thermal cooling device
931  * @np:		a pointer to a device tree node.
932  * @type:	the thermal cooling device type.
933  * @devdata:	device private data.
934  * @ops:		standard thermal cooling devices callbacks.
935  *
936  * This interface function adds a new thermal cooling device (fan/processor/...)
937  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
938  * to all the thermal zone devices registered at the same time.
939  * It also gives the opportunity to link the cooling device to a device tree
940  * node, so that it can be bound to a thermal zone created out of device tree.
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  */
945 static struct thermal_cooling_device *
__thermal_cooling_device_register(struct device_node * np,char * type,void * devdata,const struct thermal_cooling_device_ops * ops)946 __thermal_cooling_device_register(struct device_node *np,
947 				  char *type, void *devdata,
948 				  const struct thermal_cooling_device_ops *ops)
949 {
950 	struct thermal_cooling_device *cdev;
951 	struct thermal_zone_device *pos = NULL;
952 	int result;
953 
954 	if (type && strlen(type) >= THERMAL_NAME_LENGTH)
955 		return ERR_PTR(-EINVAL);
956 
957 	if (!ops || !ops->get_max_state || !ops->get_cur_state ||
958 	    !ops->set_cur_state)
959 		return ERR_PTR(-EINVAL);
960 
961 	cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
962 	if (!cdev)
963 		return ERR_PTR(-ENOMEM);
964 
965 	result = ida_simple_get(&thermal_cdev_ida, 0, 0, GFP_KERNEL);
966 	if (result < 0) {
967 		kfree(cdev);
968 		return ERR_PTR(result);
969 	}
970 
971 	cdev->id = result;
972 	strlcpy(cdev->type, type ? : "", sizeof(cdev->type));
973 	mutex_init(&cdev->lock);
974 	INIT_LIST_HEAD(&cdev->thermal_instances);
975 	cdev->np = np;
976 	cdev->ops = ops;
977 	cdev->updated = false;
978 	cdev->device.class = &thermal_class;
979 	thermal_cooling_device_setup_sysfs(cdev);
980 	cdev->devdata = devdata;
981 	dev_set_name(&cdev->device, "cooling_device%d", cdev->id);
982 	result = device_register(&cdev->device);
983 	if (result) {
984 		ida_simple_remove(&thermal_cdev_ida, cdev->id);
985 		kfree(cdev);
986 		return ERR_PTR(result);
987 	}
988 
989 	/* Add 'this' new cdev to the global cdev list */
990 	mutex_lock(&thermal_list_lock);
991 	list_add(&cdev->node, &thermal_cdev_list);
992 	mutex_unlock(&thermal_list_lock);
993 
994 	/* Update binding information for 'this' new cdev */
995 	bind_cdev(cdev);
996 
997 	mutex_lock(&thermal_list_lock);
998 	list_for_each_entry(pos, &thermal_tz_list, node)
999 		if (atomic_cmpxchg(&pos->need_update, 1, 0))
1000 			thermal_zone_device_update(pos,
1001 						   THERMAL_EVENT_UNSPECIFIED);
1002 	mutex_unlock(&thermal_list_lock);
1003 
1004 	return cdev;
1005 }
1006 
1007 /**
1008  * thermal_cooling_device_register() - register a new thermal cooling device
1009  * @type:	the thermal cooling device type.
1010  * @devdata:	device private data.
1011  * @ops:		standard thermal cooling devices callbacks.
1012  *
1013  * This interface function adds a new thermal cooling device (fan/processor/...)
1014  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
1015  * to all the thermal zone devices registered at the same time.
1016  *
1017  * Return: a pointer to the created struct thermal_cooling_device or an
1018  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
1019  */
1020 struct thermal_cooling_device *
thermal_cooling_device_register(char * type,void * devdata,const struct thermal_cooling_device_ops * ops)1021 thermal_cooling_device_register(char *type, void *devdata,
1022 				const struct thermal_cooling_device_ops *ops)
1023 {
1024 	return __thermal_cooling_device_register(NULL, type, devdata, ops);
1025 }
1026 EXPORT_SYMBOL_GPL(thermal_cooling_device_register);
1027 
1028 /**
1029  * thermal_of_cooling_device_register() - register an OF thermal cooling device
1030  * @np:		a pointer to a device tree node.
1031  * @type:	the thermal cooling device type.
1032  * @devdata:	device private data.
1033  * @ops:		standard thermal cooling devices callbacks.
1034  *
1035  * This function will register a cooling device with device tree node reference.
1036  * This interface function adds a new thermal cooling device (fan/processor/...)
1037  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
1038  * to all the thermal zone devices registered at the same time.
1039  *
1040  * Return: a pointer to the created struct thermal_cooling_device or an
1041  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
1042  */
1043 struct thermal_cooling_device *
thermal_of_cooling_device_register(struct device_node * np,char * type,void * devdata,const struct thermal_cooling_device_ops * ops)1044 thermal_of_cooling_device_register(struct device_node *np,
1045 				   char *type, void *devdata,
1046 				   const struct thermal_cooling_device_ops *ops)
1047 {
1048 	return __thermal_cooling_device_register(np, type, devdata, ops);
1049 }
1050 EXPORT_SYMBOL_GPL(thermal_of_cooling_device_register);
1051 
__unbind(struct thermal_zone_device * tz,int mask,struct thermal_cooling_device * cdev)1052 static void __unbind(struct thermal_zone_device *tz, int mask,
1053 		     struct thermal_cooling_device *cdev)
1054 {
1055 	int i;
1056 
1057 	for (i = 0; i < tz->trips; i++)
1058 		if (mask & (1 << i))
1059 			thermal_zone_unbind_cooling_device(tz, i, cdev);
1060 }
1061 
1062 /**
1063  * thermal_cooling_device_unregister - removes a thermal cooling device
1064  * @cdev:	the thermal cooling device to remove.
1065  *
1066  * thermal_cooling_device_unregister() must be called when a registered
1067  * thermal cooling device is no longer needed.
1068  */
thermal_cooling_device_unregister(struct thermal_cooling_device * cdev)1069 void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev)
1070 {
1071 	int i;
1072 	const struct thermal_zone_params *tzp;
1073 	struct thermal_zone_device *tz;
1074 	struct thermal_cooling_device *pos = NULL;
1075 
1076 	if (!cdev)
1077 		return;
1078 
1079 	mutex_lock(&thermal_list_lock);
1080 	list_for_each_entry(pos, &thermal_cdev_list, node)
1081 		if (pos == cdev)
1082 			break;
1083 	if (pos != cdev) {
1084 		/* thermal cooling device not found */
1085 		mutex_unlock(&thermal_list_lock);
1086 		return;
1087 	}
1088 	list_del(&cdev->node);
1089 
1090 	/* Unbind all thermal zones associated with 'this' cdev */
1091 	list_for_each_entry(tz, &thermal_tz_list, node) {
1092 		if (tz->ops->unbind) {
1093 			tz->ops->unbind(tz, cdev);
1094 			continue;
1095 		}
1096 
1097 		if (!tz->tzp || !tz->tzp->tbp)
1098 			continue;
1099 
1100 		tzp = tz->tzp;
1101 		for (i = 0; i < tzp->num_tbps; i++) {
1102 			if (tzp->tbp[i].cdev == cdev) {
1103 				__unbind(tz, tzp->tbp[i].trip_mask, cdev);
1104 				tzp->tbp[i].cdev = NULL;
1105 			}
1106 		}
1107 	}
1108 
1109 	mutex_unlock(&thermal_list_lock);
1110 
1111 	ida_simple_remove(&thermal_cdev_ida, cdev->id);
1112 	device_unregister(&cdev->device);
1113 }
1114 EXPORT_SYMBOL_GPL(thermal_cooling_device_unregister);
1115 
bind_tz(struct thermal_zone_device * tz)1116 static void bind_tz(struct thermal_zone_device *tz)
1117 {
1118 	int i, ret;
1119 	struct thermal_cooling_device *pos = NULL;
1120 	const struct thermal_zone_params *tzp = tz->tzp;
1121 
1122 	if (!tzp && !tz->ops->bind)
1123 		return;
1124 
1125 	mutex_lock(&thermal_list_lock);
1126 
1127 	/* If there is ops->bind, try to use ops->bind */
1128 	if (tz->ops->bind) {
1129 		list_for_each_entry(pos, &thermal_cdev_list, node) {
1130 			ret = tz->ops->bind(tz, pos);
1131 			if (ret)
1132 				print_bind_err_msg(tz, pos, ret);
1133 		}
1134 		goto exit;
1135 	}
1136 
1137 	if (!tzp || !tzp->tbp)
1138 		goto exit;
1139 
1140 	list_for_each_entry(pos, &thermal_cdev_list, node) {
1141 		for (i = 0; i < tzp->num_tbps; i++) {
1142 			if (tzp->tbp[i].cdev || !tzp->tbp[i].match)
1143 				continue;
1144 			if (tzp->tbp[i].match(tz, pos))
1145 				continue;
1146 			tzp->tbp[i].cdev = pos;
1147 			__bind(tz, tzp->tbp[i].trip_mask, pos,
1148 			       tzp->tbp[i].binding_limits,
1149 			       tzp->tbp[i].weight);
1150 		}
1151 	}
1152 exit:
1153 	mutex_unlock(&thermal_list_lock);
1154 }
1155 
1156 /**
1157  * thermal_zone_device_register() - register a new thermal zone device
1158  * @type:	the thermal zone device type
1159  * @trips:	the number of trip points the thermal zone support
1160  * @mask:	a bit string indicating the writeablility of trip points
1161  * @devdata:	private device data
1162  * @ops:	standard thermal zone device callbacks
1163  * @tzp:	thermal zone platform parameters
1164  * @passive_delay: number of milliseconds to wait between polls when
1165  *		   performing passive cooling
1166  * @polling_delay: number of milliseconds to wait between polls when checking
1167  *		   whether trip points have been crossed (0 for interrupt
1168  *		   driven systems)
1169  *
1170  * This interface function adds a new thermal zone device (sensor) to
1171  * /sys/class/thermal folder as thermal_zone[0-*]. It tries to bind all the
1172  * thermal cooling devices registered at the same time.
1173  * thermal_zone_device_unregister() must be called when the device is no
1174  * longer needed. The passive cooling depends on the .get_trend() return value.
1175  *
1176  * Return: a pointer to the created struct thermal_zone_device or an
1177  * in case of error, an ERR_PTR. Caller must check return value with
1178  * IS_ERR*() helpers.
1179  */
1180 struct thermal_zone_device *
thermal_zone_device_register(const char * type,int trips,int mask,void * devdata,struct thermal_zone_device_ops * ops,struct thermal_zone_params * tzp,int passive_delay,int polling_delay)1181 thermal_zone_device_register(const char *type, int trips, int mask,
1182 			     void *devdata, struct thermal_zone_device_ops *ops,
1183 			     struct thermal_zone_params *tzp, int passive_delay,
1184 			     int polling_delay)
1185 {
1186 	struct thermal_zone_device *tz;
1187 	enum thermal_trip_type trip_type;
1188 	int trip_temp;
1189 	int result;
1190 	int count;
1191 	struct thermal_governor *governor;
1192 
1193 	if (!type || strlen(type) == 0)
1194 		return ERR_PTR(-EINVAL);
1195 
1196 	if (type && strlen(type) >= THERMAL_NAME_LENGTH)
1197 		return ERR_PTR(-EINVAL);
1198 
1199 	if (trips > THERMAL_MAX_TRIPS || trips < 0 || mask >> trips)
1200 		return ERR_PTR(-EINVAL);
1201 
1202 	if (!ops)
1203 		return ERR_PTR(-EINVAL);
1204 
1205 	if (trips > 0 && (!ops->get_trip_type || !ops->get_trip_temp))
1206 		return ERR_PTR(-EINVAL);
1207 
1208 	tz = kzalloc(sizeof(*tz), GFP_KERNEL);
1209 	if (!tz)
1210 		return ERR_PTR(-ENOMEM);
1211 
1212 	INIT_LIST_HEAD(&tz->thermal_instances);
1213 	ida_init(&tz->ida);
1214 	mutex_init(&tz->lock);
1215 	result = ida_simple_get(&thermal_tz_ida, 0, 0, GFP_KERNEL);
1216 	if (result < 0)
1217 		goto free_tz;
1218 
1219 	tz->id = result;
1220 	strlcpy(tz->type, type, sizeof(tz->type));
1221 	tz->ops = ops;
1222 	tz->tzp = tzp;
1223 	tz->device.class = &thermal_class;
1224 	tz->devdata = devdata;
1225 	tz->trips = trips;
1226 	tz->passive_delay = passive_delay;
1227 	tz->polling_delay = polling_delay;
1228 
1229 	/* sys I/F */
1230 	/* Add nodes that are always present via .groups */
1231 	result = thermal_zone_create_device_groups(tz, mask);
1232 	if (result)
1233 		goto remove_id;
1234 
1235 	/* A new thermal zone needs to be updated anyway. */
1236 	atomic_set(&tz->need_update, 1);
1237 
1238 	dev_set_name(&tz->device, "thermal_zone%d", tz->id);
1239 	result = device_register(&tz->device);
1240 	if (result)
1241 		goto remove_device_groups;
1242 
1243 	for (count = 0; count < trips; count++) {
1244 		if (tz->ops->get_trip_type(tz, count, &trip_type))
1245 			set_bit(count, &tz->trips_disabled);
1246 		if (tz->ops->get_trip_temp(tz, count, &trip_temp))
1247 			set_bit(count, &tz->trips_disabled);
1248 		/* Check for bogus trip points */
1249 		if (trip_temp == 0)
1250 			set_bit(count, &tz->trips_disabled);
1251 	}
1252 
1253 	/* Update 'this' zone's governor information */
1254 	mutex_lock(&thermal_governor_lock);
1255 
1256 	if (tz->tzp)
1257 		governor = __find_governor(tz->tzp->governor_name);
1258 	else
1259 		governor = def_governor;
1260 
1261 	result = thermal_set_governor(tz, governor);
1262 	if (result) {
1263 		mutex_unlock(&thermal_governor_lock);
1264 		goto unregister;
1265 	}
1266 
1267 	mutex_unlock(&thermal_governor_lock);
1268 
1269 	if (!tz->tzp || !tz->tzp->no_hwmon) {
1270 		result = thermal_add_hwmon_sysfs(tz);
1271 		if (result)
1272 			goto unregister;
1273 	}
1274 
1275 	mutex_lock(&thermal_list_lock);
1276 	list_add_tail(&tz->node, &thermal_tz_list);
1277 	mutex_unlock(&thermal_list_lock);
1278 
1279 	/* Bind cooling devices for this zone */
1280 	bind_tz(tz);
1281 
1282 	INIT_DELAYED_WORK(&tz->poll_queue, thermal_zone_device_check);
1283 
1284 	thermal_zone_device_reset(tz);
1285 	/* Update the new thermal zone and mark it as already updated. */
1286 	if (atomic_cmpxchg(&tz->need_update, 1, 0))
1287 		thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
1288 
1289 	return tz;
1290 
1291 unregister:
1292 	ida_simple_remove(&thermal_tz_ida, tz->id);
1293 	device_unregister(&tz->device);
1294 	return ERR_PTR(result);
1295 
1296 remove_device_groups:
1297 	thermal_zone_destroy_device_groups(tz);
1298 remove_id:
1299 	ida_simple_remove(&thermal_tz_ida, tz->id);
1300 free_tz:
1301 	kfree(tz);
1302 	return ERR_PTR(result);
1303 }
1304 EXPORT_SYMBOL_GPL(thermal_zone_device_register);
1305 
1306 /**
1307  * thermal_device_unregister - removes the registered thermal zone device
1308  * @tz: the thermal zone device to remove
1309  */
thermal_zone_device_unregister(struct thermal_zone_device * tz)1310 void thermal_zone_device_unregister(struct thermal_zone_device *tz)
1311 {
1312 	int i;
1313 	const struct thermal_zone_params *tzp;
1314 	struct thermal_cooling_device *cdev;
1315 	struct thermal_zone_device *pos = NULL;
1316 
1317 	if (!tz)
1318 		return;
1319 
1320 	tzp = tz->tzp;
1321 
1322 	mutex_lock(&thermal_list_lock);
1323 	list_for_each_entry(pos, &thermal_tz_list, node)
1324 		if (pos == tz)
1325 			break;
1326 	if (pos != tz) {
1327 		/* thermal zone device not found */
1328 		mutex_unlock(&thermal_list_lock);
1329 		return;
1330 	}
1331 	list_del(&tz->node);
1332 
1333 	/* Unbind all cdevs associated with 'this' thermal zone */
1334 	list_for_each_entry(cdev, &thermal_cdev_list, node) {
1335 		if (tz->ops->unbind) {
1336 			tz->ops->unbind(tz, cdev);
1337 			continue;
1338 		}
1339 
1340 		if (!tzp || !tzp->tbp)
1341 			break;
1342 
1343 		for (i = 0; i < tzp->num_tbps; i++) {
1344 			if (tzp->tbp[i].cdev == cdev) {
1345 				__unbind(tz, tzp->tbp[i].trip_mask, cdev);
1346 				tzp->tbp[i].cdev = NULL;
1347 			}
1348 		}
1349 	}
1350 
1351 	mutex_unlock(&thermal_list_lock);
1352 
1353 	cancel_delayed_work_sync(&tz->poll_queue);
1354 
1355 	thermal_set_governor(tz, NULL);
1356 
1357 	thermal_remove_hwmon_sysfs(tz);
1358 	ida_simple_remove(&thermal_tz_ida, tz->id);
1359 	ida_destroy(&tz->ida);
1360 	mutex_destroy(&tz->lock);
1361 	device_unregister(&tz->device);
1362 }
1363 EXPORT_SYMBOL_GPL(thermal_zone_device_unregister);
1364 
1365 /**
1366  * thermal_zone_get_zone_by_name() - search for a zone and returns its ref
1367  * @name: thermal zone name to fetch the temperature
1368  *
1369  * When only one zone is found with the passed name, returns a reference to it.
1370  *
1371  * Return: On success returns a reference to an unique thermal zone with
1372  * matching name equals to @name, an ERR_PTR otherwise (-EINVAL for invalid
1373  * paramenters, -ENODEV for not found and -EEXIST for multiple matches).
1374  */
thermal_zone_get_zone_by_name(const char * name)1375 struct thermal_zone_device *thermal_zone_get_zone_by_name(const char *name)
1376 {
1377 	struct thermal_zone_device *pos = NULL, *ref = ERR_PTR(-EINVAL);
1378 	unsigned int found = 0;
1379 
1380 	if (!name)
1381 		goto exit;
1382 
1383 	mutex_lock(&thermal_list_lock);
1384 	list_for_each_entry(pos, &thermal_tz_list, node)
1385 		if (!strncasecmp(name, pos->type, THERMAL_NAME_LENGTH)) {
1386 			found++;
1387 			ref = pos;
1388 		}
1389 	mutex_unlock(&thermal_list_lock);
1390 
1391 	/* nothing has been found, thus an error code for it */
1392 	if (found == 0)
1393 		ref = ERR_PTR(-ENODEV);
1394 	else if (found > 1)
1395 	/* Success only when an unique zone is found */
1396 		ref = ERR_PTR(-EEXIST);
1397 
1398 exit:
1399 	return ref;
1400 }
1401 EXPORT_SYMBOL_GPL(thermal_zone_get_zone_by_name);
1402 
1403 #ifdef CONFIG_NET
1404 static const struct genl_multicast_group thermal_event_mcgrps[] = {
1405 	{ .name = THERMAL_GENL_MCAST_GROUP_NAME, },
1406 };
1407 
1408 static struct genl_family thermal_event_genl_family __ro_after_init = {
1409 	.module = THIS_MODULE,
1410 	.name = THERMAL_GENL_FAMILY_NAME,
1411 	.version = THERMAL_GENL_VERSION,
1412 	.maxattr = THERMAL_GENL_ATTR_MAX,
1413 	.mcgrps = thermal_event_mcgrps,
1414 	.n_mcgrps = ARRAY_SIZE(thermal_event_mcgrps),
1415 };
1416 
thermal_generate_netlink_event(struct thermal_zone_device * tz,enum events event)1417 int thermal_generate_netlink_event(struct thermal_zone_device *tz,
1418 				   enum events event)
1419 {
1420 	struct sk_buff *skb;
1421 	struct nlattr *attr;
1422 	struct thermal_genl_event *thermal_event;
1423 	void *msg_header;
1424 	int size;
1425 	int result;
1426 	static unsigned int thermal_event_seqnum;
1427 
1428 	if (!tz)
1429 		return -EINVAL;
1430 
1431 	/* allocate memory */
1432 	size = nla_total_size(sizeof(struct thermal_genl_event)) +
1433 	       nla_total_size(0);
1434 
1435 	skb = genlmsg_new(size, GFP_ATOMIC);
1436 	if (!skb)
1437 		return -ENOMEM;
1438 
1439 	/* add the genetlink message header */
1440 	msg_header = genlmsg_put(skb, 0, thermal_event_seqnum++,
1441 				 &thermal_event_genl_family, 0,
1442 				 THERMAL_GENL_CMD_EVENT);
1443 	if (!msg_header) {
1444 		nlmsg_free(skb);
1445 		return -ENOMEM;
1446 	}
1447 
1448 	/* fill the data */
1449 	attr = nla_reserve(skb, THERMAL_GENL_ATTR_EVENT,
1450 			   sizeof(struct thermal_genl_event));
1451 
1452 	if (!attr) {
1453 		nlmsg_free(skb);
1454 		return -EINVAL;
1455 	}
1456 
1457 	thermal_event = nla_data(attr);
1458 	if (!thermal_event) {
1459 		nlmsg_free(skb);
1460 		return -EINVAL;
1461 	}
1462 
1463 	memset(thermal_event, 0, sizeof(struct thermal_genl_event));
1464 
1465 	thermal_event->orig = tz->id;
1466 	thermal_event->event = event;
1467 
1468 	/* send multicast genetlink message */
1469 	genlmsg_end(skb, msg_header);
1470 
1471 	result = genlmsg_multicast(&thermal_event_genl_family, skb, 0,
1472 				   0, GFP_ATOMIC);
1473 	if (result)
1474 		dev_err(&tz->device, "Failed to send netlink event:%d", result);
1475 
1476 	return result;
1477 }
1478 EXPORT_SYMBOL_GPL(thermal_generate_netlink_event);
1479 
genetlink_init(void)1480 static int __init genetlink_init(void)
1481 {
1482 	return genl_register_family(&thermal_event_genl_family);
1483 }
1484 
genetlink_exit(void)1485 static void genetlink_exit(void)
1486 {
1487 	genl_unregister_family(&thermal_event_genl_family);
1488 }
1489 #else /* !CONFIG_NET */
genetlink_init(void)1490 static inline int genetlink_init(void) { return 0; }
genetlink_exit(void)1491 static inline void genetlink_exit(void) {}
1492 #endif /* !CONFIG_NET */
1493 
thermal_pm_notify(struct notifier_block * nb,unsigned long mode,void * _unused)1494 static int thermal_pm_notify(struct notifier_block *nb,
1495 			     unsigned long mode, void *_unused)
1496 {
1497 	struct thermal_zone_device *tz;
1498 
1499 	switch (mode) {
1500 	case PM_HIBERNATION_PREPARE:
1501 	case PM_RESTORE_PREPARE:
1502 	case PM_SUSPEND_PREPARE:
1503 		atomic_set(&in_suspend, 1);
1504 		break;
1505 	case PM_POST_HIBERNATION:
1506 	case PM_POST_RESTORE:
1507 	case PM_POST_SUSPEND:
1508 		atomic_set(&in_suspend, 0);
1509 		list_for_each_entry(tz, &thermal_tz_list, node) {
1510 			thermal_zone_device_init(tz);
1511 			thermal_zone_device_update(tz,
1512 						   THERMAL_EVENT_UNSPECIFIED);
1513 		}
1514 		break;
1515 	default:
1516 		break;
1517 	}
1518 	return 0;
1519 }
1520 
1521 static struct notifier_block thermal_pm_nb = {
1522 	.notifier_call = thermal_pm_notify,
1523 };
1524 
thermal_init(void)1525 static int __init thermal_init(void)
1526 {
1527 	int result;
1528 
1529 	mutex_init(&poweroff_lock);
1530 	result = thermal_register_governors();
1531 	if (result)
1532 		goto error;
1533 
1534 	result = class_register(&thermal_class);
1535 	if (result)
1536 		goto unregister_governors;
1537 
1538 	result = genetlink_init();
1539 	if (result)
1540 		goto unregister_class;
1541 
1542 	result = of_parse_thermal_zones();
1543 	if (result)
1544 		goto exit_netlink;
1545 
1546 	result = register_pm_notifier(&thermal_pm_nb);
1547 	if (result)
1548 		pr_warn("Thermal: Can not register suspend notifier, return %d\n",
1549 			result);
1550 
1551 	return 0;
1552 
1553 exit_netlink:
1554 	genetlink_exit();
1555 unregister_class:
1556 	class_unregister(&thermal_class);
1557 unregister_governors:
1558 	thermal_unregister_governors();
1559 error:
1560 	ida_destroy(&thermal_tz_ida);
1561 	ida_destroy(&thermal_cdev_ida);
1562 	mutex_destroy(&thermal_list_lock);
1563 	mutex_destroy(&thermal_governor_lock);
1564 	mutex_destroy(&poweroff_lock);
1565 	return result;
1566 }
1567 
thermal_exit(void)1568 static void __exit thermal_exit(void)
1569 {
1570 	unregister_pm_notifier(&thermal_pm_nb);
1571 	of_thermal_destroy_zones();
1572 	genetlink_exit();
1573 	class_unregister(&thermal_class);
1574 	thermal_unregister_governors();
1575 	ida_destroy(&thermal_tz_ida);
1576 	ida_destroy(&thermal_cdev_ida);
1577 	mutex_destroy(&thermal_list_lock);
1578 	mutex_destroy(&thermal_governor_lock);
1579 }
1580 
1581 fs_initcall(thermal_init);
1582 module_exit(thermal_exit);
1583