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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 *  thermal.c - Generic Thermal Management Sysfs support.
   4 *
   5 *  Copyright (C) 2008 Intel Corp
   6 *  Copyright (C) 2008 Zhang Rui <rui.zhang@intel.com>
   7 *  Copyright (C) 2008 Sujith Thomas <sujith.thomas@intel.com>
   8 */
   9
  10#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  11
  12#include <linux/device.h>
  13#include <linux/err.h>
  14#include <linux/export.h>
  15#include <linux/slab.h>
  16#include <linux/kdev_t.h>
  17#include <linux/idr.h>
  18#include <linux/thermal.h>
  19#include <linux/reboot.h>
  20#include <linux/string.h>
  21#include <linux/of.h>
  22#include <linux/suspend.h>
  23
  24#define CREATE_TRACE_POINTS
  25#include "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 struct thermal_governor *def_governor;
  41
  42/*
  43 * Governor section: set of functions to handle thermal governors
  44 *
  45 * Functions to help in the life cycle of thermal governors within
  46 * the thermal core and by the thermal governor code.
  47 */
  48
  49static struct thermal_governor *__find_governor(const char *name)
  50{
  51	struct thermal_governor *pos;
  52
  53	if (!name || !name[0])
  54		return def_governor;
  55
  56	list_for_each_entry(pos, &thermal_governor_list, governor_list)
  57		if (!strncasecmp(name, pos->name, THERMAL_NAME_LENGTH))
  58			return pos;
  59
  60	return NULL;
  61}
  62
  63/**
  64 * bind_previous_governor() - bind the previous governor of the thermal zone
  65 * @tz:		a valid pointer to a struct thermal_zone_device
  66 * @failed_gov_name:	the name of the governor that failed to register
  67 *
  68 * Register the previous governor of the thermal zone after a new
  69 * governor has failed to be bound.
  70 */
  71static void bind_previous_governor(struct thermal_zone_device *tz,
  72				   const char *failed_gov_name)
  73{
  74	if (tz->governor && tz->governor->bind_to_tz) {
  75		if (tz->governor->bind_to_tz(tz)) {
  76			dev_err(&tz->device,
  77				"governor %s failed to bind and the previous one (%s) failed to bind again, thermal zone %s has no governor\n",
  78				failed_gov_name, tz->governor->name, tz->type);
  79			tz->governor = NULL;
  80		}
  81	}
  82}
  83
  84/**
  85 * thermal_set_governor() - Switch to another governor
  86 * @tz:		a valid pointer to a struct thermal_zone_device
  87 * @new_gov:	pointer to the new governor
  88 *
  89 * Change the governor of thermal zone @tz.
  90 *
  91 * Return: 0 on success, an error if the new governor's bind_to_tz() failed.
  92 */
  93static int thermal_set_governor(struct thermal_zone_device *tz,
  94				struct thermal_governor *new_gov)
  95{
  96	int ret = 0;
  97
  98	if (tz->governor && tz->governor->unbind_from_tz)
  99		tz->governor->unbind_from_tz(tz);
 100
 101	if (new_gov && new_gov->bind_to_tz) {
 102		ret = new_gov->bind_to_tz(tz);
 103		if (ret) {
 104			bind_previous_governor(tz, new_gov->name);
 105
 106			return ret;
 107		}
 108	}
 109
 110	tz->governor = new_gov;
 111
 112	return ret;
 113}
 114
 115int thermal_register_governor(struct thermal_governor *governor)
 116{
 117	int err;
 118	const char *name;
 119	struct thermal_zone_device *pos;
 120
 121	if (!governor)
 122		return -EINVAL;
 123
 124	mutex_lock(&thermal_governor_lock);
 125
 126	err = -EBUSY;
 127	if (!__find_governor(governor->name)) {
 128		bool match_default;
 129
 130		err = 0;
 131		list_add(&governor->governor_list, &thermal_governor_list);
 132		match_default = !strncmp(governor->name,
 133					 DEFAULT_THERMAL_GOVERNOR,
 134					 THERMAL_NAME_LENGTH);
 135
 136		if (!def_governor && match_default)
 137			def_governor = governor;
 138	}
 139
 140	mutex_lock(&thermal_list_lock);
 141
 142	list_for_each_entry(pos, &thermal_tz_list, node) {
 143		/*
 144		 * only thermal zones with specified tz->tzp->governor_name
 145		 * may run with tz->govenor unset
 146		 */
 147		if (pos->governor)
 148			continue;
 149
 150		name = pos->tzp->governor_name;
 151
 152		if (!strncasecmp(name, governor->name, THERMAL_NAME_LENGTH)) {
 153			int ret;
 154
 155			ret = thermal_set_governor(pos, governor);
 156			if (ret)
 157				dev_err(&pos->device,
 158					"Failed to set governor %s for thermal zone %s: %d\n",
 159					governor->name, pos->type, ret);
 160		}
 161	}
 162
 163	mutex_unlock(&thermal_list_lock);
 164	mutex_unlock(&thermal_governor_lock);
 165
 166	return err;
 167}
 168
 169void thermal_unregister_governor(struct thermal_governor *governor)
 170{
 171	struct thermal_zone_device *pos;
 172
 173	if (!governor)
 174		return;
 175
 176	mutex_lock(&thermal_governor_lock);
 177
 178	if (!__find_governor(governor->name))
 179		goto exit;
 180
 181	mutex_lock(&thermal_list_lock);
 182
 183	list_for_each_entry(pos, &thermal_tz_list, node) {
 184		if (!strncasecmp(pos->governor->name, governor->name,
 185				 THERMAL_NAME_LENGTH))
 186			thermal_set_governor(pos, NULL);
 187	}
 188
 189	mutex_unlock(&thermal_list_lock);
 190	list_del(&governor->governor_list);
 191exit:
 192	mutex_unlock(&thermal_governor_lock);
 193}
 194
 195int thermal_zone_device_set_policy(struct thermal_zone_device *tz,
 196				   char *policy)
 197{
 198	struct thermal_governor *gov;
 199	int ret = -EINVAL;
 200
 201	mutex_lock(&thermal_governor_lock);
 202	mutex_lock(&tz->lock);
 203
 204	gov = __find_governor(strim(policy));
 205	if (!gov)
 206		goto exit;
 207
 208	ret = thermal_set_governor(tz, gov);
 209
 210exit:
 211	mutex_unlock(&tz->lock);
 212	mutex_unlock(&thermal_governor_lock);
 213
 214	thermal_notify_tz_gov_change(tz, policy);
 215
 216	return ret;
 217}
 218
 219int thermal_build_list_of_policies(char *buf)
 220{
 221	struct thermal_governor *pos;
 222	ssize_t count = 0;
 223
 224	mutex_lock(&thermal_governor_lock);
 225
 226	list_for_each_entry(pos, &thermal_governor_list, governor_list) {
 227		count += sysfs_emit_at(buf, count, "%s ", pos->name);
 228	}
 229	count += sysfs_emit_at(buf, count, "\n");
 230
 231	mutex_unlock(&thermal_governor_lock);
 232
 233	return count;
 234}
 235
 236static void __init thermal_unregister_governors(void)
 237{
 238	struct thermal_governor **governor;
 239
 240	for_each_governor_table(governor)
 241		thermal_unregister_governor(*governor);
 242}
 243
 244static int __init thermal_register_governors(void)
 245{
 246	int ret = 0;
 247	struct thermal_governor **governor;
 248
 249	for_each_governor_table(governor) {
 250		ret = thermal_register_governor(*governor);
 251		if (ret) {
 252			pr_err("Failed to register governor: '%s'",
 253			       (*governor)->name);
 254			break;
 255		}
 256
 257		pr_info("Registered thermal governor '%s'",
 258			(*governor)->name);
 259	}
 260
 261	if (ret) {
 262		struct thermal_governor **gov;
 263
 264		for_each_governor_table(gov) {
 265			if (gov == governor)
 266				break;
 267			thermal_unregister_governor(*gov);
 268		}
 269	}
 270
 271	return ret;
 272}
 273
 274/*
 275 * Zone update section: main control loop applied to each zone while monitoring
 276 * in polling mode. The monitoring is done using a workqueue.
 277 * Same update may be done on a zone by calling thermal_zone_device_update().
 278 *
 279 * An update means:
 280 * - Non-critical trips will invoke the governor responsible for that zone;
 281 * - Hot trips will produce a notification to userspace;
 282 * - Critical trip point will cause a system shutdown.
 283 */
 284static void thermal_zone_device_set_polling(struct thermal_zone_device *tz,
 285					    unsigned long delay)
 286{
 287	if (delay)
 288		mod_delayed_work(system_freezable_power_efficient_wq,
 289				 &tz->poll_queue, delay);
 290	else
 291		cancel_delayed_work(&tz->poll_queue);
 292}
 293
 294static void monitor_thermal_zone(struct thermal_zone_device *tz)
 295{
 296	if (tz->mode != THERMAL_DEVICE_ENABLED)
 297		thermal_zone_device_set_polling(tz, 0);
 298	else if (tz->passive)
 299		thermal_zone_device_set_polling(tz, tz->passive_delay_jiffies);
 300	else if (tz->polling_delay_jiffies)
 301		thermal_zone_device_set_polling(tz, tz->polling_delay_jiffies);
 302}
 303
 304static void handle_non_critical_trips(struct thermal_zone_device *tz,
 305				      const struct thermal_trip *trip)
 306{
 307	tz->governor ? tz->governor->throttle(tz, trip) :
 308		       def_governor->throttle(tz, trip);
 309}
 310
 311void thermal_governor_update_tz(struct thermal_zone_device *tz,
 312				enum thermal_notify_event reason)
 313{
 314	if (!tz->governor || !tz->governor->update_tz)
 315		return;
 316
 317	tz->governor->update_tz(tz, reason);
 318}
 319
 320static void thermal_zone_device_halt(struct thermal_zone_device *tz, bool shutdown)
 321{
 322	/*
 323	 * poweroff_delay_ms must be a carefully profiled positive value.
 324	 * Its a must for forced_emergency_poweroff_work to be scheduled.
 325	 */
 326	int poweroff_delay_ms = CONFIG_THERMAL_EMERGENCY_POWEROFF_DELAY_MS;
 327	const char *msg = "Temperature too high";
 328
 329	dev_emerg(&tz->device, "%s: critical temperature reached\n", tz->type);
 330
 331	if (shutdown)
 332		hw_protection_shutdown(msg, poweroff_delay_ms);
 333	else
 334		hw_protection_reboot(msg, poweroff_delay_ms);
 335}
 336
 337void thermal_zone_device_critical(struct thermal_zone_device *tz)
 338{
 339	thermal_zone_device_halt(tz, true);
 340}
 341EXPORT_SYMBOL(thermal_zone_device_critical);
 342
 343void thermal_zone_device_critical_reboot(struct thermal_zone_device *tz)
 344{
 345	thermal_zone_device_halt(tz, false);
 346}
 347
 348static void handle_critical_trips(struct thermal_zone_device *tz,
 349				  const struct thermal_trip *trip)
 350{
 351	/* If we have not crossed the trip_temp, we do not care. */
 352	if (trip->temperature <= 0 || tz->temperature < trip->temperature)
 353		return;
 354
 355	trace_thermal_zone_trip(tz, thermal_zone_trip_id(tz, trip), trip->type);
 356
 357	if (trip->type == THERMAL_TRIP_CRITICAL)
 358		tz->ops.critical(tz);
 359	else if (tz->ops.hot)
 360		tz->ops.hot(tz);
 361}
 362
 363static void handle_thermal_trip(struct thermal_zone_device *tz,
 364				struct thermal_trip *trip)
 365{
 366	if (trip->temperature == THERMAL_TEMP_INVALID)
 367		return;
 368
 369	if (tz->last_temperature == THERMAL_TEMP_INVALID) {
 370		/* Initialization. */
 371		trip->threshold = trip->temperature;
 372		if (tz->temperature >= trip->threshold)
 373			trip->threshold -= trip->hysteresis;
 374	} else if (tz->last_temperature < trip->threshold) {
 375		/*
 376		 * The trip threshold is equal to the trip temperature, unless
 377		 * the latter has changed in the meantime.  In either case,
 378		 * the trip is crossed if the current zone temperature is at
 379		 * least equal to its temperature, but otherwise ensure that
 380		 * the threshold and the trip temperature will be equal.
 381		 */
 382		if (tz->temperature >= trip->temperature) {
 383			thermal_notify_tz_trip_up(tz, trip);
 384			thermal_debug_tz_trip_up(tz, trip);
 385			trip->threshold = trip->temperature - trip->hysteresis;
 386		} else {
 387			trip->threshold = trip->temperature;
 388		}
 389	} else {
 390		/*
 391		 * The previous zone temperature was above or equal to the trip
 392		 * threshold, which would be equal to the "low temperature" of
 393		 * the trip (its temperature minus its hysteresis), unless the
 394		 * trip temperature or hysteresis had changed.  In either case,
 395		 * the trip is crossed if the current zone temperature is below
 396		 * the low temperature of the trip, but otherwise ensure that
 397		 * the trip threshold will be equal to the low temperature of
 398		 * the trip.
 399		 */
 400		if (tz->temperature < trip->temperature - trip->hysteresis) {
 401			thermal_notify_tz_trip_down(tz, trip);
 402			thermal_debug_tz_trip_down(tz, trip);
 403			trip->threshold = trip->temperature;
 404		} else {
 405			trip->threshold = trip->temperature - trip->hysteresis;
 406		}
 407	}
 408
 409	if (trip->type == THERMAL_TRIP_CRITICAL || trip->type == THERMAL_TRIP_HOT)
 410		handle_critical_trips(tz, trip);
 411	else
 412		handle_non_critical_trips(tz, trip);
 413}
 414
 415static void update_temperature(struct thermal_zone_device *tz)
 416{
 417	int temp, ret;
 418
 419	ret = __thermal_zone_get_temp(tz, &temp);
 420	if (ret) {
 421		if (ret != -EAGAIN)
 422			dev_warn(&tz->device,
 423				 "failed to read out thermal zone (%d)\n",
 424				 ret);
 425		return;
 426	}
 427
 428	tz->last_temperature = tz->temperature;
 429	tz->temperature = temp;
 430
 431	trace_thermal_temperature(tz);
 432
 433	thermal_genl_sampling_temp(tz->id, temp);
 434}
 435
 436static void thermal_zone_device_check(struct work_struct *work)
 437{
 438	struct thermal_zone_device *tz = container_of(work, struct
 439						      thermal_zone_device,
 440						      poll_queue.work);
 441	thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
 442}
 443
 444static void thermal_zone_device_init(struct thermal_zone_device *tz)
 445{
 446	struct thermal_instance *pos;
 447
 448	INIT_DELAYED_WORK(&tz->poll_queue, thermal_zone_device_check);
 449
 450	tz->temperature = THERMAL_TEMP_INVALID;
 451	tz->prev_low_trip = -INT_MAX;
 452	tz->prev_high_trip = INT_MAX;
 453	list_for_each_entry(pos, &tz->thermal_instances, tz_node)
 454		pos->initialized = false;
 455}
 456
 457void __thermal_zone_device_update(struct thermal_zone_device *tz,
 458				  enum thermal_notify_event event)
 459{
 460	struct thermal_trip *trip;
 461
 462	if (tz->suspended)
 463		return;
 464
 465	if (!thermal_zone_device_is_enabled(tz))
 466		return;
 467
 468	update_temperature(tz);
 469
 470	__thermal_zone_set_trips(tz);
 471
 472	tz->notify_event = event;
 473
 474	for_each_trip(tz, trip)
 475		handle_thermal_trip(tz, trip);
 476
 477	thermal_debug_update_temp(tz);
 478
 479	monitor_thermal_zone(tz);
 480}
 481
 482static int thermal_zone_device_set_mode(struct thermal_zone_device *tz,
 483					enum thermal_device_mode mode)
 484{
 485	int ret = 0;
 486
 487	mutex_lock(&tz->lock);
 488
 489	/* do nothing if mode isn't changing */
 490	if (mode == tz->mode) {
 491		mutex_unlock(&tz->lock);
 492
 493		return ret;
 494	}
 495
 496	if (tz->ops.change_mode)
 497		ret = tz->ops.change_mode(tz, mode);
 498
 499	if (!ret)
 500		tz->mode = mode;
 501
 502	__thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
 503
 504	mutex_unlock(&tz->lock);
 505
 506	if (mode == THERMAL_DEVICE_ENABLED)
 507		thermal_notify_tz_enable(tz);
 508	else
 509		thermal_notify_tz_disable(tz);
 510
 511	return ret;
 512}
 513
 514int thermal_zone_device_enable(struct thermal_zone_device *tz)
 515{
 516	return thermal_zone_device_set_mode(tz, THERMAL_DEVICE_ENABLED);
 517}
 518EXPORT_SYMBOL_GPL(thermal_zone_device_enable);
 519
 520int thermal_zone_device_disable(struct thermal_zone_device *tz)
 521{
 522	return thermal_zone_device_set_mode(tz, THERMAL_DEVICE_DISABLED);
 523}
 524EXPORT_SYMBOL_GPL(thermal_zone_device_disable);
 525
 526int thermal_zone_device_is_enabled(struct thermal_zone_device *tz)
 527{
 528	lockdep_assert_held(&tz->lock);
 529
 530	return tz->mode == THERMAL_DEVICE_ENABLED;
 531}
 532
 533static bool thermal_zone_is_present(struct thermal_zone_device *tz)
 534{
 535	return !list_empty(&tz->node);
 536}
 537
 538void thermal_zone_device_update(struct thermal_zone_device *tz,
 539				enum thermal_notify_event event)
 540{
 541	mutex_lock(&tz->lock);
 542	if (thermal_zone_is_present(tz))
 543		__thermal_zone_device_update(tz, event);
 544	mutex_unlock(&tz->lock);
 545}
 546EXPORT_SYMBOL_GPL(thermal_zone_device_update);
 547
 548int for_each_thermal_governor(int (*cb)(struct thermal_governor *, void *),
 549			      void *data)
 550{
 551	struct thermal_governor *gov;
 552	int ret = 0;
 553
 554	mutex_lock(&thermal_governor_lock);
 555	list_for_each_entry(gov, &thermal_governor_list, governor_list) {
 556		ret = cb(gov, data);
 557		if (ret)
 558			break;
 559	}
 560	mutex_unlock(&thermal_governor_lock);
 561
 562	return ret;
 563}
 564
 565int for_each_thermal_cooling_device(int (*cb)(struct thermal_cooling_device *,
 566					      void *), void *data)
 567{
 568	struct thermal_cooling_device *cdev;
 569	int ret = 0;
 570
 571	mutex_lock(&thermal_list_lock);
 572	list_for_each_entry(cdev, &thermal_cdev_list, node) {
 573		ret = cb(cdev, data);
 574		if (ret)
 575			break;
 576	}
 577	mutex_unlock(&thermal_list_lock);
 578
 579	return ret;
 580}
 581
 582int for_each_thermal_zone(int (*cb)(struct thermal_zone_device *, void *),
 583			  void *data)
 584{
 585	struct thermal_zone_device *tz;
 586	int ret = 0;
 587
 588	mutex_lock(&thermal_list_lock);
 589	list_for_each_entry(tz, &thermal_tz_list, node) {
 590		ret = cb(tz, data);
 591		if (ret)
 592			break;
 593	}
 594	mutex_unlock(&thermal_list_lock);
 595
 596	return ret;
 597}
 598
 599struct thermal_zone_device *thermal_zone_get_by_id(int id)
 600{
 601	struct thermal_zone_device *tz, *match = NULL;
 602
 603	mutex_lock(&thermal_list_lock);
 604	list_for_each_entry(tz, &thermal_tz_list, node) {
 605		if (tz->id == id) {
 606			match = tz;
 607			break;
 608		}
 609	}
 610	mutex_unlock(&thermal_list_lock);
 611
 612	return match;
 613}
 614
 615/*
 616 * Device management section: cooling devices, zones devices, and binding
 617 *
 618 * Set of functions provided by the thermal core for:
 619 * - cooling devices lifecycle: registration, unregistration,
 620 *				binding, and unbinding.
 621 * - thermal zone devices lifecycle: registration, unregistration,
 622 *				     binding, and unbinding.
 623 */
 624
 625/**
 626 * thermal_bind_cdev_to_trip - bind a cooling device to a thermal zone
 627 * @tz:		pointer to struct thermal_zone_device
 628 * @trip:	trip point the cooling devices is associated with in this zone.
 629 * @cdev:	pointer to struct thermal_cooling_device
 630 * @upper:	the Maximum cooling state for this trip point.
 631 *		THERMAL_NO_LIMIT means no upper limit,
 632 *		and the cooling device can be in max_state.
 633 * @lower:	the Minimum cooling state can be used for this trip point.
 634 *		THERMAL_NO_LIMIT means no lower limit,
 635 *		and the cooling device can be in cooling state 0.
 636 * @weight:	The weight of the cooling device to be bound to the
 637 *		thermal zone. Use THERMAL_WEIGHT_DEFAULT for the
 638 *		default value
 639 *
 640 * This interface function bind a thermal cooling device to the certain trip
 641 * point of a thermal zone device.
 642 * This function is usually called in the thermal zone device .bind callback.
 643 *
 644 * Return: 0 on success, the proper error value otherwise.
 645 */
 646int thermal_bind_cdev_to_trip(struct thermal_zone_device *tz,
 647				     const struct thermal_trip *trip,
 648				     struct thermal_cooling_device *cdev,
 649				     unsigned long upper, unsigned long lower,
 650				     unsigned int weight)
 651{
 652	struct thermal_instance *dev;
 653	struct thermal_instance *pos;
 654	struct thermal_zone_device *pos1;
 655	struct thermal_cooling_device *pos2;
 656	bool upper_no_limit;
 657	int result;
 658
 659	list_for_each_entry(pos1, &thermal_tz_list, node) {
 660		if (pos1 == tz)
 661			break;
 662	}
 663	list_for_each_entry(pos2, &thermal_cdev_list, node) {
 664		if (pos2 == cdev)
 665			break;
 666	}
 667
 668	if (tz != pos1 || cdev != pos2)
 669		return -EINVAL;
 670
 671	/* lower default 0, upper default max_state */
 672	lower = lower == THERMAL_NO_LIMIT ? 0 : lower;
 673
 674	if (upper == THERMAL_NO_LIMIT) {
 675		upper = cdev->max_state;
 676		upper_no_limit = true;
 677	} else {
 678		upper_no_limit = false;
 679	}
 680
 681	if (lower > upper || upper > cdev->max_state)
 682		return -EINVAL;
 683
 684	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 685	if (!dev)
 686		return -ENOMEM;
 687	dev->tz = tz;
 688	dev->cdev = cdev;
 689	dev->trip = trip;
 690	dev->upper = upper;
 691	dev->upper_no_limit = upper_no_limit;
 692	dev->lower = lower;
 693	dev->target = THERMAL_NO_TARGET;
 694	dev->weight = weight;
 695
 696	result = ida_alloc(&tz->ida, GFP_KERNEL);
 697	if (result < 0)
 698		goto free_mem;
 699
 700	dev->id = result;
 701	sprintf(dev->name, "cdev%d", dev->id);
 702	result =
 703	    sysfs_create_link(&tz->device.kobj, &cdev->device.kobj, dev->name);
 704	if (result)
 705		goto release_ida;
 706
 707	snprintf(dev->attr_name, sizeof(dev->attr_name), "cdev%d_trip_point",
 708		 dev->id);
 709	sysfs_attr_init(&dev->attr.attr);
 710	dev->attr.attr.name = dev->attr_name;
 711	dev->attr.attr.mode = 0444;
 712	dev->attr.show = trip_point_show;
 713	result = device_create_file(&tz->device, &dev->attr);
 714	if (result)
 715		goto remove_symbol_link;
 716
 717	snprintf(dev->weight_attr_name, sizeof(dev->weight_attr_name),
 718		 "cdev%d_weight", dev->id);
 719	sysfs_attr_init(&dev->weight_attr.attr);
 720	dev->weight_attr.attr.name = dev->weight_attr_name;
 721	dev->weight_attr.attr.mode = S_IWUSR | S_IRUGO;
 722	dev->weight_attr.show = weight_show;
 723	dev->weight_attr.store = weight_store;
 724	result = device_create_file(&tz->device, &dev->weight_attr);
 725	if (result)
 726		goto remove_trip_file;
 727
 728	mutex_lock(&tz->lock);
 729	mutex_lock(&cdev->lock);
 730	list_for_each_entry(pos, &tz->thermal_instances, tz_node)
 731		if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
 732			result = -EEXIST;
 733			break;
 734		}
 735	if (!result) {
 736		list_add_tail(&dev->tz_node, &tz->thermal_instances);
 737		list_add_tail(&dev->cdev_node, &cdev->thermal_instances);
 738		atomic_set(&tz->need_update, 1);
 739
 740		thermal_governor_update_tz(tz, THERMAL_TZ_BIND_CDEV);
 741	}
 742	mutex_unlock(&cdev->lock);
 743	mutex_unlock(&tz->lock);
 744
 745	if (!result)
 746		return 0;
 747
 748	device_remove_file(&tz->device, &dev->weight_attr);
 749remove_trip_file:
 750	device_remove_file(&tz->device, &dev->attr);
 751remove_symbol_link:
 752	sysfs_remove_link(&tz->device.kobj, dev->name);
 753release_ida:
 754	ida_free(&tz->ida, dev->id);
 755free_mem:
 756	kfree(dev);
 757	return result;
 758}
 759EXPORT_SYMBOL_GPL(thermal_bind_cdev_to_trip);
 760
 761int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz,
 762				     int trip_index,
 763				     struct thermal_cooling_device *cdev,
 764				     unsigned long upper, unsigned long lower,
 765				     unsigned int weight)
 766{
 767	if (trip_index < 0 || trip_index >= tz->num_trips)
 768		return -EINVAL;
 769
 770	return thermal_bind_cdev_to_trip(tz, &tz->trips[trip_index], cdev,
 771					 upper, lower, weight);
 772}
 773EXPORT_SYMBOL_GPL(thermal_zone_bind_cooling_device);
 774
 775/**
 776 * thermal_unbind_cdev_from_trip - unbind a cooling device from a thermal zone.
 777 * @tz:		pointer to a struct thermal_zone_device.
 778 * @trip:	trip point the cooling devices is associated with in this zone.
 779 * @cdev:	pointer to a struct thermal_cooling_device.
 780 *
 781 * This interface function unbind a thermal cooling device from the certain
 782 * trip point of a thermal zone device.
 783 * This function is usually called in the thermal zone device .unbind callback.
 784 *
 785 * Return: 0 on success, the proper error value otherwise.
 786 */
 787int thermal_unbind_cdev_from_trip(struct thermal_zone_device *tz,
 788				  const struct thermal_trip *trip,
 789				  struct thermal_cooling_device *cdev)
 790{
 791	struct thermal_instance *pos, *next;
 792
 793	mutex_lock(&tz->lock);
 794	mutex_lock(&cdev->lock);
 795	list_for_each_entry_safe(pos, next, &tz->thermal_instances, tz_node) {
 796		if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
 797			list_del(&pos->tz_node);
 798			list_del(&pos->cdev_node);
 799
 800			thermal_governor_update_tz(tz, THERMAL_TZ_UNBIND_CDEV);
 801
 802			mutex_unlock(&cdev->lock);
 803			mutex_unlock(&tz->lock);
 804			goto unbind;
 805		}
 806	}
 807	mutex_unlock(&cdev->lock);
 808	mutex_unlock(&tz->lock);
 809
 810	return -ENODEV;
 811
 812unbind:
 813	device_remove_file(&tz->device, &pos->weight_attr);
 814	device_remove_file(&tz->device, &pos->attr);
 815	sysfs_remove_link(&tz->device.kobj, pos->name);
 816	ida_free(&tz->ida, pos->id);
 817	kfree(pos);
 818	return 0;
 819}
 820EXPORT_SYMBOL_GPL(thermal_unbind_cdev_from_trip);
 821
 822int thermal_zone_unbind_cooling_device(struct thermal_zone_device *tz,
 823				       int trip_index,
 824				       struct thermal_cooling_device *cdev)
 825{
 826	if (trip_index < 0 || trip_index >= tz->num_trips)
 827		return -EINVAL;
 828
 829	return thermal_unbind_cdev_from_trip(tz, &tz->trips[trip_index], cdev);
 830}
 831EXPORT_SYMBOL_GPL(thermal_zone_unbind_cooling_device);
 832
 833static void thermal_release(struct device *dev)
 834{
 835	struct thermal_zone_device *tz;
 836	struct thermal_cooling_device *cdev;
 837
 838	if (!strncmp(dev_name(dev), "thermal_zone",
 839		     sizeof("thermal_zone") - 1)) {
 840		tz = to_thermal_zone(dev);
 841		thermal_zone_destroy_device_groups(tz);
 842		mutex_destroy(&tz->lock);
 843		complete(&tz->removal);
 844	} else if (!strncmp(dev_name(dev), "cooling_device",
 845			    sizeof("cooling_device") - 1)) {
 846		cdev = to_cooling_device(dev);
 847		thermal_cooling_device_destroy_sysfs(cdev);
 848		kfree_const(cdev->type);
 849		ida_free(&thermal_cdev_ida, cdev->id);
 850		kfree(cdev);
 851	}
 852}
 853
 854static struct class *thermal_class;
 855
 856static inline
 857void print_bind_err_msg(struct thermal_zone_device *tz,
 858			struct thermal_cooling_device *cdev, int ret)
 859{
 860	dev_err(&tz->device, "binding zone %s with cdev %s failed:%d\n",
 861		tz->type, cdev->type, ret);
 862}
 863
 864static void bind_cdev(struct thermal_cooling_device *cdev)
 865{
 866	int ret;
 867	struct thermal_zone_device *pos = NULL;
 868
 869	list_for_each_entry(pos, &thermal_tz_list, node) {
 870		if (pos->ops.bind) {
 871			ret = pos->ops.bind(pos, cdev);
 872			if (ret)
 873				print_bind_err_msg(pos, cdev, ret);
 874		}
 875	}
 876}
 877
 878/**
 879 * __thermal_cooling_device_register() - register a new thermal cooling device
 880 * @np:		a pointer to a device tree node.
 881 * @type:	the thermal cooling device type.
 882 * @devdata:	device private data.
 883 * @ops:		standard thermal cooling devices callbacks.
 884 *
 885 * This interface function adds a new thermal cooling device (fan/processor/...)
 886 * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
 887 * to all the thermal zone devices registered at the same time.
 888 * It also gives the opportunity to link the cooling device to a device tree
 889 * node, so that it can be bound to a thermal zone created out of device tree.
 890 *
 891 * Return: a pointer to the created struct thermal_cooling_device or an
 892 * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
 893 */
 894static struct thermal_cooling_device *
 895__thermal_cooling_device_register(struct device_node *np,
 896				  const char *type, void *devdata,
 897				  const struct thermal_cooling_device_ops *ops)
 898{
 899	struct thermal_cooling_device *cdev;
 900	struct thermal_zone_device *pos = NULL;
 901	unsigned long current_state;
 902	int id, ret;
 903
 904	if (!ops || !ops->get_max_state || !ops->get_cur_state ||
 905	    !ops->set_cur_state)
 906		return ERR_PTR(-EINVAL);
 907
 908	if (!thermal_class)
 909		return ERR_PTR(-ENODEV);
 910
 911	cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
 912	if (!cdev)
 913		return ERR_PTR(-ENOMEM);
 914
 915	ret = ida_alloc(&thermal_cdev_ida, GFP_KERNEL);
 916	if (ret < 0)
 917		goto out_kfree_cdev;
 918	cdev->id = ret;
 919	id = ret;
 920
 921	cdev->type = kstrdup_const(type ? type : "", GFP_KERNEL);
 922	if (!cdev->type) {
 923		ret = -ENOMEM;
 924		goto out_ida_remove;
 925	}
 926
 927	mutex_init(&cdev->lock);
 928	INIT_LIST_HEAD(&cdev->thermal_instances);
 929	cdev->np = np;
 930	cdev->ops = ops;
 931	cdev->updated = false;
 932	cdev->device.class = thermal_class;
 933	cdev->devdata = devdata;
 934
 935	ret = cdev->ops->get_max_state(cdev, &cdev->max_state);
 936	if (ret)
 937		goto out_cdev_type;
 938
 939	ret = cdev->ops->get_cur_state(cdev, &current_state);
 940	if (ret)
 941		goto out_cdev_type;
 942
 943	thermal_cooling_device_setup_sysfs(cdev);
 944
 945	ret = dev_set_name(&cdev->device, "cooling_device%d", cdev->id);
 946	if (ret)
 947		goto out_cooling_dev;
 948
 949	ret = device_register(&cdev->device);
 950	if (ret) {
 951		/* thermal_release() handles rest of the cleanup */
 952		put_device(&cdev->device);
 953		return ERR_PTR(ret);
 954	}
 955
 956	thermal_debug_cdev_add(cdev, current_state);
 957
 958	/* Add 'this' new cdev to the global cdev list */
 959	mutex_lock(&thermal_list_lock);
 960
 961	list_add(&cdev->node, &thermal_cdev_list);
 962
 963	/* Update binding information for 'this' new cdev */
 964	bind_cdev(cdev);
 965
 966	list_for_each_entry(pos, &thermal_tz_list, node)
 967		if (atomic_cmpxchg(&pos->need_update, 1, 0))
 968			thermal_zone_device_update(pos,
 969						   THERMAL_EVENT_UNSPECIFIED);
 970
 971	mutex_unlock(&thermal_list_lock);
 972
 973	return cdev;
 974
 975out_cooling_dev:
 976	thermal_cooling_device_destroy_sysfs(cdev);
 977out_cdev_type:
 978	kfree_const(cdev->type);
 979out_ida_remove:
 980	ida_free(&thermal_cdev_ida, id);
 981out_kfree_cdev:
 982	kfree(cdev);
 983	return ERR_PTR(ret);
 984}
 985
 986/**
 987 * thermal_cooling_device_register() - register a new thermal cooling device
 988 * @type:	the thermal cooling device type.
 989 * @devdata:	device private data.
 990 * @ops:		standard thermal cooling devices callbacks.
 991 *
 992 * This interface function adds a new thermal cooling device (fan/processor/...)
 993 * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
 994 * to all the thermal zone devices registered at the same time.
 995 *
 996 * Return: a pointer to the created struct thermal_cooling_device or an
 997 * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
 998 */
 999struct thermal_cooling_device *
1000thermal_cooling_device_register(const char *type, void *devdata,
1001				const struct thermal_cooling_device_ops *ops)
1002{
1003	return __thermal_cooling_device_register(NULL, type, devdata, ops);
1004}
1005EXPORT_SYMBOL_GPL(thermal_cooling_device_register);
1006
1007/**
1008 * thermal_of_cooling_device_register() - register an OF thermal cooling device
1009 * @np:		a pointer to a device tree node.
1010 * @type:	the thermal cooling device type.
1011 * @devdata:	device private data.
1012 * @ops:		standard thermal cooling devices callbacks.
1013 *
1014 * This function will register a cooling device with device tree node reference.
1015 * This interface function adds a new thermal cooling device (fan/processor/...)
1016 * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
1017 * to all the thermal zone devices registered at the same time.
1018 *
1019 * Return: a pointer to the created struct thermal_cooling_device or an
1020 * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
1021 */
1022struct thermal_cooling_device *
1023thermal_of_cooling_device_register(struct device_node *np,
1024				   const char *type, void *devdata,
1025				   const struct thermal_cooling_device_ops *ops)
1026{
1027	return __thermal_cooling_device_register(np, type, devdata, ops);
1028}
1029EXPORT_SYMBOL_GPL(thermal_of_cooling_device_register);
1030
1031static void thermal_cooling_device_release(struct device *dev, void *res)
1032{
1033	thermal_cooling_device_unregister(
1034				*(struct thermal_cooling_device **)res);
1035}
1036
1037/**
1038 * devm_thermal_of_cooling_device_register() - register an OF thermal cooling
1039 *					       device
1040 * @dev:	a valid struct device pointer of a sensor device.
1041 * @np:		a pointer to a device tree node.
1042 * @type:	the thermal cooling device type.
1043 * @devdata:	device private data.
1044 * @ops:	standard thermal cooling devices callbacks.
1045 *
1046 * This function will register a cooling device with device tree node reference.
1047 * This interface function adds a new thermal cooling device (fan/processor/...)
1048 * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
1049 * to all the thermal zone devices registered at the same time.
1050 *
1051 * Return: a pointer to the created struct thermal_cooling_device or an
1052 * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
1053 */
1054struct thermal_cooling_device *
1055devm_thermal_of_cooling_device_register(struct device *dev,
1056				struct device_node *np,
1057				char *type, void *devdata,
1058				const struct thermal_cooling_device_ops *ops)
1059{
1060	struct thermal_cooling_device **ptr, *tcd;
1061
1062	ptr = devres_alloc(thermal_cooling_device_release, sizeof(*ptr),
1063			   GFP_KERNEL);
1064	if (!ptr)
1065		return ERR_PTR(-ENOMEM);
1066
1067	tcd = __thermal_cooling_device_register(np, type, devdata, ops);
1068	if (IS_ERR(tcd)) {
1069		devres_free(ptr);
1070		return tcd;
1071	}
1072
1073	*ptr = tcd;
1074	devres_add(dev, ptr);
1075
1076	return tcd;
1077}
1078EXPORT_SYMBOL_GPL(devm_thermal_of_cooling_device_register);
1079
1080static bool thermal_cooling_device_present(struct thermal_cooling_device *cdev)
1081{
1082	struct thermal_cooling_device *pos = NULL;
1083
1084	list_for_each_entry(pos, &thermal_cdev_list, node) {
1085		if (pos == cdev)
1086			return true;
1087	}
1088
1089	return false;
1090}
1091
1092/**
1093 * thermal_cooling_device_update - Update a cooling device object
1094 * @cdev: Target cooling device.
1095 *
1096 * Update @cdev to reflect a change of the underlying hardware or platform.
1097 *
1098 * Must be called when the maximum cooling state of @cdev becomes invalid and so
1099 * its .get_max_state() callback needs to be run to produce the new maximum
1100 * cooling state value.
1101 */
1102void thermal_cooling_device_update(struct thermal_cooling_device *cdev)
1103{
1104	struct thermal_instance *ti;
1105	unsigned long state;
1106
1107	if (IS_ERR_OR_NULL(cdev))
1108		return;
1109
1110	/*
1111	 * Hold thermal_list_lock throughout the update to prevent the device
1112	 * from going away while being updated.
1113	 */
1114	mutex_lock(&thermal_list_lock);
1115
1116	if (!thermal_cooling_device_present(cdev))
1117		goto unlock_list;
1118
1119	/*
1120	 * Update under the cdev lock to prevent the state from being set beyond
1121	 * the new limit concurrently.
1122	 */
1123	mutex_lock(&cdev->lock);
1124
1125	if (cdev->ops->get_max_state(cdev, &cdev->max_state))
1126		goto unlock;
1127
1128	thermal_cooling_device_stats_reinit(cdev);
1129
1130	list_for_each_entry(ti, &cdev->thermal_instances, cdev_node) {
1131		if (ti->upper == cdev->max_state)
1132			continue;
1133
1134		if (ti->upper < cdev->max_state) {
1135			if (ti->upper_no_limit)
1136				ti->upper = cdev->max_state;
1137
1138			continue;
1139		}
1140
1141		ti->upper = cdev->max_state;
1142		if (ti->lower > ti->upper)
1143			ti->lower = ti->upper;
1144
1145		if (ti->target == THERMAL_NO_TARGET)
1146			continue;
1147
1148		if (ti->target > ti->upper)
1149			ti->target = ti->upper;
1150	}
1151
1152	if (cdev->ops->get_cur_state(cdev, &state) || state > cdev->max_state)
1153		goto unlock;
1154
1155	thermal_cooling_device_stats_update(cdev, state);
1156
1157unlock:
1158	mutex_unlock(&cdev->lock);
1159
1160unlock_list:
1161	mutex_unlock(&thermal_list_lock);
1162}
1163EXPORT_SYMBOL_GPL(thermal_cooling_device_update);
1164
1165/**
1166 * thermal_cooling_device_unregister - removes a thermal cooling device
1167 * @cdev:	the thermal cooling device to remove.
1168 *
1169 * thermal_cooling_device_unregister() must be called when a registered
1170 * thermal cooling device is no longer needed.
1171 */
1172void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev)
1173{
1174	struct thermal_zone_device *tz;
1175
1176	if (!cdev)
1177		return;
1178
1179	thermal_debug_cdev_remove(cdev);
1180
1181	mutex_lock(&thermal_list_lock);
1182
1183	if (!thermal_cooling_device_present(cdev)) {
1184		mutex_unlock(&thermal_list_lock);
1185		return;
1186	}
1187
1188	list_del(&cdev->node);
1189
1190	/* Unbind all thermal zones associated with 'this' cdev */
1191	list_for_each_entry(tz, &thermal_tz_list, node) {
1192		if (tz->ops.unbind)
1193			tz->ops.unbind(tz, cdev);
1194	}
1195
1196	mutex_unlock(&thermal_list_lock);
1197
1198	device_unregister(&cdev->device);
1199}
1200EXPORT_SYMBOL_GPL(thermal_cooling_device_unregister);
1201
1202static void bind_tz(struct thermal_zone_device *tz)
1203{
1204	int ret;
1205	struct thermal_cooling_device *pos = NULL;
1206
1207	if (!tz->ops.bind)
1208		return;
1209
1210	mutex_lock(&thermal_list_lock);
1211
1212	list_for_each_entry(pos, &thermal_cdev_list, node) {
1213		ret = tz->ops.bind(tz, pos);
1214		if (ret)
1215			print_bind_err_msg(tz, pos, ret);
1216	}
1217
1218	mutex_unlock(&thermal_list_lock);
1219}
1220
1221static void thermal_set_delay_jiffies(unsigned long *delay_jiffies, int delay_ms)
1222{
1223	*delay_jiffies = msecs_to_jiffies(delay_ms);
1224	if (delay_ms > 1000)
1225		*delay_jiffies = round_jiffies(*delay_jiffies);
1226}
1227
1228int thermal_zone_get_crit_temp(struct thermal_zone_device *tz, int *temp)
1229{
1230	int i, ret = -EINVAL;
1231
1232	if (tz->ops.get_crit_temp)
1233		return tz->ops.get_crit_temp(tz, temp);
1234
1235	mutex_lock(&tz->lock);
1236
1237	for (i = 0; i < tz->num_trips; i++) {
1238		if (tz->trips[i].type == THERMAL_TRIP_CRITICAL) {
1239			*temp = tz->trips[i].temperature;
1240			ret = 0;
1241			break;
1242		}
1243	}
1244
1245	mutex_unlock(&tz->lock);
1246
1247	return ret;
1248}
1249EXPORT_SYMBOL_GPL(thermal_zone_get_crit_temp);
1250
1251/**
1252 * thermal_zone_device_register_with_trips() - register a new thermal zone device
1253 * @type:	the thermal zone device type
1254 * @trips:	a pointer to an array of thermal trips
1255 * @num_trips:	the number of trip points the thermal zone support
1256 * @devdata:	private device data
1257 * @ops:	standard thermal zone device callbacks
1258 * @tzp:	thermal zone platform parameters
1259 * @passive_delay: number of milliseconds to wait between polls when
1260 *		   performing passive cooling
1261 * @polling_delay: number of milliseconds to wait between polls when checking
1262 *		   whether trip points have been crossed (0 for interrupt
1263 *		   driven systems)
1264 *
1265 * This interface function adds a new thermal zone device (sensor) to
1266 * /sys/class/thermal folder as thermal_zone[0-*]. It tries to bind all the
1267 * thermal cooling devices registered at the same time.
1268 * thermal_zone_device_unregister() must be called when the device is no
1269 * longer needed. The passive cooling depends on the .get_trend() return value.
1270 *
1271 * Return: a pointer to the created struct thermal_zone_device or an
1272 * in case of error, an ERR_PTR. Caller must check return value with
1273 * IS_ERR*() helpers.
1274 */
1275struct thermal_zone_device *
1276thermal_zone_device_register_with_trips(const char *type,
1277					const struct thermal_trip *trips,
1278					int num_trips, void *devdata,
1279					const struct thermal_zone_device_ops *ops,
1280					const struct thermal_zone_params *tzp,
1281					int passive_delay, int polling_delay)
1282{
1283	struct thermal_zone_device *tz;
1284	int id;
1285	int result;
1286	struct thermal_governor *governor;
1287
1288	if (!type || strlen(type) == 0) {
1289		pr_err("No thermal zone type defined\n");
1290		return ERR_PTR(-EINVAL);
1291	}
1292
1293	if (strlen(type) >= THERMAL_NAME_LENGTH) {
1294		pr_err("Thermal zone name (%s) too long, should be under %d chars\n",
1295		       type, THERMAL_NAME_LENGTH);
1296		return ERR_PTR(-EINVAL);
1297	}
1298
1299	if (num_trips < 0) {
1300		pr_err("Incorrect number of thermal trips\n");
1301		return ERR_PTR(-EINVAL);
1302	}
1303
1304	if (!ops || !ops->get_temp) {
1305		pr_err("Thermal zone device ops not defined\n");
1306		return ERR_PTR(-EINVAL);
1307	}
1308
1309	if (num_trips > 0 && !trips)
1310		return ERR_PTR(-EINVAL);
1311
1312	if (!thermal_class)
1313		return ERR_PTR(-ENODEV);
1314
1315	tz = kzalloc(struct_size(tz, trips, num_trips), GFP_KERNEL);
1316	if (!tz)
1317		return ERR_PTR(-ENOMEM);
1318
1319	if (tzp) {
1320		tz->tzp = kmemdup(tzp, sizeof(*tzp), GFP_KERNEL);
1321		if (!tz->tzp) {
1322			result = -ENOMEM;
1323			goto free_tz;
1324		}
1325	}
1326
1327	INIT_LIST_HEAD(&tz->thermal_instances);
1328	INIT_LIST_HEAD(&tz->node);
1329	ida_init(&tz->ida);
1330	mutex_init(&tz->lock);
1331	init_completion(&tz->removal);
1332	id = ida_alloc(&thermal_tz_ida, GFP_KERNEL);
1333	if (id < 0) {
1334		result = id;
1335		goto free_tzp;
1336	}
1337
1338	tz->id = id;
1339	strscpy(tz->type, type, sizeof(tz->type));
1340
1341	tz->ops = *ops;
1342	if (!tz->ops.critical)
1343		tz->ops.critical = thermal_zone_device_critical;
1344
1345	tz->device.class = thermal_class;
1346	tz->devdata = devdata;
1347	tz->num_trips = num_trips;
1348	memcpy(tz->trips, trips, num_trips * sizeof(*trips));
1349
1350	thermal_set_delay_jiffies(&tz->passive_delay_jiffies, passive_delay);
1351	thermal_set_delay_jiffies(&tz->polling_delay_jiffies, polling_delay);
1352
1353	/* sys I/F */
1354	/* Add nodes that are always present via .groups */
1355	result = thermal_zone_create_device_groups(tz);
1356	if (result)
1357		goto remove_id;
1358
1359	/* A new thermal zone needs to be updated anyway. */
1360	atomic_set(&tz->need_update, 1);
1361
1362	result = dev_set_name(&tz->device, "thermal_zone%d", tz->id);
1363	if (result) {
1364		thermal_zone_destroy_device_groups(tz);
1365		goto remove_id;
1366	}
1367	result = device_register(&tz->device);
1368	if (result)
1369		goto release_device;
1370
1371	/* Update 'this' zone's governor information */
1372	mutex_lock(&thermal_governor_lock);
1373
1374	if (tz->tzp)
1375		governor = __find_governor(tz->tzp->governor_name);
1376	else
1377		governor = def_governor;
1378
1379	result = thermal_set_governor(tz, governor);
1380	if (result) {
1381		mutex_unlock(&thermal_governor_lock);
1382		goto unregister;
1383	}
1384
1385	mutex_unlock(&thermal_governor_lock);
1386
1387	if (!tz->tzp || !tz->tzp->no_hwmon) {
1388		result = thermal_add_hwmon_sysfs(tz);
1389		if (result)
1390			goto unregister;
1391	}
1392
1393	mutex_lock(&thermal_list_lock);
1394	mutex_lock(&tz->lock);
1395	list_add_tail(&tz->node, &thermal_tz_list);
1396	mutex_unlock(&tz->lock);
1397	mutex_unlock(&thermal_list_lock);
1398
1399	/* Bind cooling devices for this zone */
1400	bind_tz(tz);
1401
1402	thermal_zone_device_init(tz);
1403	/* Update the new thermal zone and mark it as already updated. */
1404	if (atomic_cmpxchg(&tz->need_update, 1, 0))
1405		thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
1406
1407	thermal_notify_tz_create(tz);
1408
1409	thermal_debug_tz_add(tz);
1410
1411	return tz;
1412
1413unregister:
1414	device_del(&tz->device);
1415release_device:
1416	put_device(&tz->device);
1417remove_id:
1418	ida_free(&thermal_tz_ida, id);
1419free_tzp:
1420	kfree(tz->tzp);
1421free_tz:
1422	kfree(tz);
1423	return ERR_PTR(result);
1424}
1425EXPORT_SYMBOL_GPL(thermal_zone_device_register_with_trips);
1426
1427struct thermal_zone_device *thermal_tripless_zone_device_register(
1428					const char *type,
1429					void *devdata,
1430					const struct thermal_zone_device_ops *ops,
1431					const struct thermal_zone_params *tzp)
1432{
1433	return thermal_zone_device_register_with_trips(type, NULL, 0, devdata,
1434						       ops, tzp, 0, 0);
1435}
1436EXPORT_SYMBOL_GPL(thermal_tripless_zone_device_register);
1437
1438void *thermal_zone_device_priv(struct thermal_zone_device *tzd)
1439{
1440	return tzd->devdata;
1441}
1442EXPORT_SYMBOL_GPL(thermal_zone_device_priv);
1443
1444const char *thermal_zone_device_type(struct thermal_zone_device *tzd)
1445{
1446	return tzd->type;
1447}
1448EXPORT_SYMBOL_GPL(thermal_zone_device_type);
1449
1450int thermal_zone_device_id(struct thermal_zone_device *tzd)
1451{
1452	return tzd->id;
1453}
1454EXPORT_SYMBOL_GPL(thermal_zone_device_id);
1455
1456struct device *thermal_zone_device(struct thermal_zone_device *tzd)
1457{
1458	return &tzd->device;
1459}
1460EXPORT_SYMBOL_GPL(thermal_zone_device);
1461
1462/**
1463 * thermal_zone_device_unregister - removes the registered thermal zone device
1464 * @tz: the thermal zone device to remove
1465 */
1466void thermal_zone_device_unregister(struct thermal_zone_device *tz)
1467{
1468	struct thermal_cooling_device *cdev;
1469	struct thermal_zone_device *pos = NULL;
1470
1471	if (!tz)
1472		return;
1473
1474	thermal_debug_tz_remove(tz);
1475
1476	mutex_lock(&thermal_list_lock);
1477	list_for_each_entry(pos, &thermal_tz_list, node)
1478		if (pos == tz)
1479			break;
1480	if (pos != tz) {
1481		/* thermal zone device not found */
1482		mutex_unlock(&thermal_list_lock);
1483		return;
1484	}
1485
1486	mutex_lock(&tz->lock);
1487	list_del(&tz->node);
1488	mutex_unlock(&tz->lock);
1489
1490	/* Unbind all cdevs associated with 'this' thermal zone */
1491	list_for_each_entry(cdev, &thermal_cdev_list, node)
1492		if (tz->ops.unbind)
1493			tz->ops.unbind(tz, cdev);
1494
1495	mutex_unlock(&thermal_list_lock);
1496
1497	cancel_delayed_work_sync(&tz->poll_queue);
1498
1499	thermal_set_governor(tz, NULL);
1500
1501	thermal_remove_hwmon_sysfs(tz);
1502	ida_free(&thermal_tz_ida, tz->id);
1503	ida_destroy(&tz->ida);
1504
1505	device_del(&tz->device);
1506
1507	kfree(tz->tzp);
1508
1509	put_device(&tz->device);
1510
1511	thermal_notify_tz_delete(tz);
1512
1513	wait_for_completion(&tz->removal);
1514	kfree(tz);
1515}
1516EXPORT_SYMBOL_GPL(thermal_zone_device_unregister);
1517
1518/**
1519 * thermal_zone_get_zone_by_name() - search for a zone and returns its ref
1520 * @name: thermal zone name to fetch the temperature
1521 *
1522 * When only one zone is found with the passed name, returns a reference to it.
1523 *
1524 * Return: On success returns a reference to an unique thermal zone with
1525 * matching name equals to @name, an ERR_PTR otherwise (-EINVAL for invalid
1526 * paramenters, -ENODEV for not found and -EEXIST for multiple matches).
1527 */
1528struct thermal_zone_device *thermal_zone_get_zone_by_name(const char *name)
1529{
1530	struct thermal_zone_device *pos = NULL, *ref = ERR_PTR(-EINVAL);
1531	unsigned int found = 0;
1532
1533	if (!name)
1534		goto exit;
1535
1536	mutex_lock(&thermal_list_lock);
1537	list_for_each_entry(pos, &thermal_tz_list, node)
1538		if (!strncasecmp(name, pos->type, THERMAL_NAME_LENGTH)) {
1539			found++;
1540			ref = pos;
1541		}
1542	mutex_unlock(&thermal_list_lock);
1543
1544	/* nothing has been found, thus an error code for it */
1545	if (found == 0)
1546		ref = ERR_PTR(-ENODEV);
1547	else if (found > 1)
1548	/* Success only when an unique zone is found */
1549		ref = ERR_PTR(-EEXIST);
1550
1551exit:
1552	return ref;
1553}
1554EXPORT_SYMBOL_GPL(thermal_zone_get_zone_by_name);
1555
1556static void thermal_zone_device_resume(struct work_struct *work)
1557{
1558	struct thermal_zone_device *tz;
1559
1560	tz = container_of(work, struct thermal_zone_device, poll_queue.work);
1561
1562	mutex_lock(&tz->lock);
1563
1564	tz->suspended = false;
1565
1566	thermal_zone_device_init(tz);
1567	__thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
1568
1569	mutex_unlock(&tz->lock);
1570}
1571
1572static int thermal_pm_notify(struct notifier_block *nb,
1573			     unsigned long mode, void *_unused)
1574{
1575	struct thermal_zone_device *tz;
1576
1577	switch (mode) {
1578	case PM_HIBERNATION_PREPARE:
1579	case PM_RESTORE_PREPARE:
1580	case PM_SUSPEND_PREPARE:
1581		mutex_lock(&thermal_list_lock);
1582
1583		list_for_each_entry(tz, &thermal_tz_list, node) {
1584			mutex_lock(&tz->lock);
1585
1586			tz->suspended = true;
1587
1588			mutex_unlock(&tz->lock);
1589		}
1590
1591		mutex_unlock(&thermal_list_lock);
1592		break;
1593	case PM_POST_HIBERNATION:
1594	case PM_POST_RESTORE:
1595	case PM_POST_SUSPEND:
1596		mutex_lock(&thermal_list_lock);
1597
1598		list_for_each_entry(tz, &thermal_tz_list, node) {
1599			mutex_lock(&tz->lock);
1600
1601			cancel_delayed_work(&tz->poll_queue);
1602
1603			/*
1604			 * Replace the work function with the resume one, which
1605			 * will restore the original work function and schedule
1606			 * the polling work if needed.
1607			 */
1608			INIT_DELAYED_WORK(&tz->poll_queue,
1609					  thermal_zone_device_resume);
1610			/* Queue up the work without a delay. */
1611			mod_delayed_work(system_freezable_power_efficient_wq,
1612					 &tz->poll_queue, 0);
1613
1614			mutex_unlock(&tz->lock);
1615		}
1616
1617		mutex_unlock(&thermal_list_lock);
1618		break;
1619	default:
1620		break;
1621	}
1622	return 0;
1623}
1624
1625static struct notifier_block thermal_pm_nb = {
1626	.notifier_call = thermal_pm_notify,
1627};
1628
1629static int __init thermal_init(void)
1630{
1631	int result;
1632
1633	thermal_debug_init();
1634
1635	result = thermal_netlink_init();
1636	if (result)
1637		goto error;
1638
1639	result = thermal_register_governors();
1640	if (result)
1641		goto unregister_netlink;
1642
1643	thermal_class = kzalloc(sizeof(*thermal_class), GFP_KERNEL);
1644	if (!thermal_class) {
1645		result = -ENOMEM;
1646		goto unregister_governors;
1647	}
1648
1649	thermal_class->name = "thermal";
1650	thermal_class->dev_release = thermal_release;
1651
1652	result = class_register(thermal_class);
1653	if (result) {
1654		kfree(thermal_class);
1655		thermal_class = NULL;
1656		goto unregister_governors;
1657	}
1658
1659	result = register_pm_notifier(&thermal_pm_nb);
1660	if (result)
1661		pr_warn("Thermal: Can not register suspend notifier, return %d\n",
1662			result);
1663
1664	return 0;
1665
1666unregister_governors:
1667	thermal_unregister_governors();
1668unregister_netlink:
1669	thermal_netlink_exit();
1670error:
1671	mutex_destroy(&thermal_list_lock);
1672	mutex_destroy(&thermal_governor_lock);
1673	return result;
1674}
1675postcore_initcall(thermal_init);