drivers/thermal/thermal_core.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  thermal.c - Generic Thermal Management Sysfs support.
   4  *
   5  *  Copyright (C) 2008 Intel Corp
   6  *  Copyright (C) 2008 Zhang Rui <rui.zhang@intel.com>
   7  *  Copyright (C) 2008 Sujith Thomas <sujith.thomas@intel.com>
   8  */
   9
  10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  11
  12 #include <linux/device.h>
  13 #include <linux/err.h>
  14 #include <linux/export.h>
  15 #include <linux/slab.h>
  16 #include <linux/kdev_t.h>
  17 #include <linux/idr.h>
  18 #include <linux/thermal.h>
  19 #include <linux/reboot.h>
  20 #include <linux/string.h>
  21 #include <linux/of.h>
  22 #include <linux/suspend.h>
  23
  24 #define CREATE_TRACE_POINTS
  25 #include <trace/events/thermal.h>
  26
  27 #include "thermal_core.h"
  28 #include "thermal_hwmon.h"
  29
  30 static DEFINE_IDA(thermal_tz_ida);
  31 static DEFINE_IDA(thermal_cdev_ida);
  32
  33 static LIST_HEAD(thermal_tz_list);
  34 static LIST_HEAD(thermal_cdev_list);
  35 static LIST_HEAD(thermal_governor_list);
  36
  37 static DEFINE_MUTEX(thermal_list_lock);
  38 static DEFINE_MUTEX(thermal_governor_lock);
  39 static DEFINE_MUTEX(poweroff_lock);
  40
  41 static atomic_t in_suspend;
  42 static bool power_off_triggered;
  43
  44 static struct thermal_governor *def_governor;
  45
  46 /*
  47  * Governor section: set of functions to handle thermal governors
  48  *
  49  * Functions to help in the life cycle of thermal governors within
  50  * the thermal core and by the thermal governor code.
  51  */
  52
  53 static struct thermal_governor *__find_governor(const char *name)
  54 {
  55         struct thermal_governor *pos;
  56
  57         if (!name || !name[0])
  58                 return def_governor;
  59
  60         list_for_each_entry(pos, &thermal_governor_list, governor_list)
  61                 if (!strncasecmp(name, pos->name, THERMAL_NAME_LENGTH))
  62                         return pos;
  63
  64         return NULL;
  65 }
  66
  67 /**
  68  * bind_previous_governor() - bind the previous governor of the thermal zone
  69  * @tz:         a valid pointer to a struct thermal_zone_device
  70  * @failed_gov_name:    the name of the governor that failed to register
  71  *
  72  * Register the previous governor of the thermal zone after a new
  73  * governor has failed to be bound.
  74  */
  75 static void bind_previous_governor(struct thermal_zone_device *tz,
  76                                    const char *failed_gov_name)
  77 {
  78         if (tz->governor && tz->governor->bind_to_tz) {
  79                 if (tz->governor->bind_to_tz(tz)) {
  80                         dev_err(&tz->device,
  81                                 "governor %s failed to bind and the previous one (%s) failed to bind again, thermal zone %s has no governor\n",
  82                                 failed_gov_name, tz->governor->name, tz->type);
  83                         tz->governor = NULL;
  84                 }
  85         }
  86 }
  87
  88 /**
  89  * thermal_set_governor() - Switch to another governor
  90  * @tz:         a valid pointer to a struct thermal_zone_device
  91  * @new_gov:    pointer to the new governor
  92  *
  93  * Change the governor of thermal zone @tz.
  94  *
  95  * Return: 0 on success, an error if the new governor's bind_to_tz() failed.
  96  */
  97 static int thermal_set_governor(struct thermal_zone_device *tz,
  98                                 struct thermal_governor *new_gov)
  99 {
 100         int ret = 0;
 101
 102         if (tz->governor && tz->governor->unbind_from_tz)
 103                 tz->governor->unbind_from_tz(tz);
 104
 105         if (new_gov && new_gov->bind_to_tz) {
 106                 ret = new_gov->bind_to_tz(tz);
 107                 if (ret) {
 108                         bind_previous_governor(tz, new_gov->name);
 109
 110                         return ret;
 111                 }
 112         }
 113
 114         tz->governor = new_gov;
 115
 116         return ret;
 117 }
 118
 119 int thermal_register_governor(struct thermal_governor *governor)
 120 {
 121         int err;
 122         const char *name;
 123         struct thermal_zone_device *pos;
 124
 125         if (!governor)
 126                 return -EINVAL;
 127
 128         mutex_lock(&thermal_governor_lock);
 129
 130         err = -EBUSY;
 131         if (!__find_governor(governor->name)) {
 132                 bool match_default;
 133
 134                 err = 0;
 135                 list_add(&governor->governor_list, &thermal_governor_list);
 136                 match_default = !strncmp(governor->name,
 137                                          DEFAULT_THERMAL_GOVERNOR,
 138                                          THERMAL_NAME_LENGTH);
 139
 140                 if (!def_governor && match_default)
 141                         def_governor = governor;
 142         }
 143
 144         mutex_lock(&thermal_list_lock);
 145
 146         list_for_each_entry(pos, &thermal_tz_list, node) {
 147                 /*
 148                  * only thermal zones with specified tz->tzp->governor_name
 149                  * may run with tz->govenor unset
 150                  */
 151                 if (pos->governor)
 152                         continue;
 153
 154                 name = pos->tzp->governor_name;
 155
 156                 if (!strncasecmp(name, governor->name, THERMAL_NAME_LENGTH)) {
 157                         int ret;
 158
 159                         ret = thermal_set_governor(pos, governor);
 160                         if (ret)
 161                                 dev_err(&pos->device,
 162                                         "Failed to set governor %s for thermal zone %s: %d\n",
 163                                         governor->name, pos->type, ret);
 164                 }
 165         }
 166
 167         mutex_unlock(&thermal_list_lock);
 168         mutex_unlock(&thermal_governor_lock);
 169
 170         return err;
 171 }
 172
 173 void thermal_unregister_governor(struct thermal_governor *governor)
 174 {
 175         struct thermal_zone_device *pos;
 176
 177         if (!governor)
 178                 return;
 179
 180         mutex_lock(&thermal_governor_lock);
 181
 182         if (!__find_governor(governor->name))
 183                 goto exit;
 184
 185         mutex_lock(&thermal_list_lock);
 186
 187         list_for_each_entry(pos, &thermal_tz_list, node) {
 188                 if (!strncasecmp(pos->governor->name, governor->name,
 189                                  THERMAL_NAME_LENGTH))
 190                         thermal_set_governor(pos, NULL);
 191         }
 192
 193         mutex_unlock(&thermal_list_lock);
 194         list_del(&governor->governor_list);
 195 exit:
 196         mutex_unlock(&thermal_governor_lock);
 197 }
 198
 199 int thermal_zone_device_set_policy(struct thermal_zone_device *tz,
 200                                    char *policy)
 201 {
 202         struct thermal_governor *gov;
 203         int ret = -EINVAL;
 204
 205         mutex_lock(&thermal_governor_lock);
 206         mutex_lock(&tz->lock);
 207
 208         gov = __find_governor(strim(policy));
 209         if (!gov)
 210                 goto exit;
 211
 212         ret = thermal_set_governor(tz, gov);
 213
 214 exit:
 215         mutex_unlock(&tz->lock);
 216         mutex_unlock(&thermal_governor_lock);
 217
 218         thermal_notify_tz_gov_change(tz->id, policy);
 219
 220         return ret;
 221 }
 222
 223 int thermal_build_list_of_policies(char *buf)
 224 {
 225         struct thermal_governor *pos;
 226         ssize_t count = 0;
 227         ssize_t size = PAGE_SIZE;
 228
 229         mutex_lock(&thermal_governor_lock);
 230
 231         list_for_each_entry(pos, &thermal_governor_list, governor_list) {
 232                 size = PAGE_SIZE - count;
 233                 count += scnprintf(buf + count, size, "%s ", pos->name);
 234         }
 235         count += scnprintf(buf + count, size, "\n");
 236
 237         mutex_unlock(&thermal_governor_lock);
 238
 239         return count;
 240 }
 241
 242 static void __init thermal_unregister_governors(void)
 243 {
 244         struct thermal_governor **governor;
 245
 246         for_each_governor_table(governor)
 247                 thermal_unregister_governor(*governor);
 248 }
 249
 250 static int __init thermal_register_governors(void)
 251 {
 252         int ret = 0;
 253         struct thermal_governor **governor;
 254
 255         for_each_governor_table(governor) {
 256                 ret = thermal_register_governor(*governor);
 257                 if (ret) {
 258                         pr_err("Failed to register governor: '%s'",
 259                                (*governor)->name);
 260                         break;
 261                 }
 262
 263                 pr_info("Registered thermal governor '%s'",
 264                         (*governor)->name);
 265         }
 266
 267         if (ret) {
 268                 struct thermal_governor **gov;
 269
 270                 for_each_governor_table(gov) {
 271                         if (gov == governor)
 272                                 break;
 273                         thermal_unregister_governor(*gov);
 274                 }
 275         }
 276
 277         return ret;
 278 }
 279
 280 /*
 281  * Zone update section: main control loop applied to each zone while monitoring
 282  *
 283  * in polling mode. The monitoring is done using a workqueue.
 284  * Same update may be done on a zone by calling thermal_zone_device_update().
 285  *
 286  * An update means:
 287  * - Non-critical trips will invoke the governor responsible for that zone;
 288  * - Hot trips will produce a notification to userspace;
 289  * - Critical trip point will cause a system shutdown.
 290  */
 291 static void thermal_zone_device_set_polling(struct thermal_zone_device *tz,
 292                                             int delay)
 293 {
 294         if (delay > 1000)
 295                 mod_delayed_work(system_freezable_power_efficient_wq,
 296                                  &tz->poll_queue,
 297                                  round_jiffies(msecs_to_jiffies(delay)));
 298         else if (delay)
 299                 mod_delayed_work(system_freezable_power_efficient_wq,
 300                                  &tz->poll_queue,
 301                                  msecs_to_jiffies(delay));
 302         else
 303                 cancel_delayed_work(&tz->poll_queue);
 304 }
 305
 306 static inline bool should_stop_polling(struct thermal_zone_device *tz)
 307 {
 308         return !thermal_zone_device_is_enabled(tz);
 309 }
 310
 311 static void monitor_thermal_zone(struct thermal_zone_device *tz)
 312 {
 313         bool stop;
 314
 315         stop = should_stop_polling(tz);
 316
 317         mutex_lock(&tz->lock);
 318
 319         if (!stop && tz->passive)
 320                 thermal_zone_device_set_polling(tz, tz->passive_delay);
 321         else if (!stop && tz->polling_delay)
 322                 thermal_zone_device_set_polling(tz, tz->polling_delay);
 323         else
 324                 thermal_zone_device_set_polling(tz, 0);
 325
 326         mutex_unlock(&tz->lock);
 327 }
 328
 329 static void handle_non_critical_trips(struct thermal_zone_device *tz, int trip)
 330 {
 331         tz->governor ? tz->governor->throttle(tz, trip) :
 332                        def_governor->throttle(tz, trip);
 333 }
 334
 335 /**
 336  * thermal_emergency_poweroff_func - emergency poweroff work after a known delay
 337  * @work: work_struct associated with the emergency poweroff function
 338  *
 339  * This function is called in very critical situations to force
 340  * a kernel poweroff after a configurable timeout value.
 341  */
 342 static void thermal_emergency_poweroff_func(struct work_struct *work)
 343 {
 344         /*
 345          * We have reached here after the emergency thermal shutdown
 346          * Waiting period has expired. This means orderly_poweroff has
 347          * not been able to shut off the system for some reason.
 348          * Try to shut down the system immediately using kernel_power_off
 349          * if populated
 350          */
 351         WARN(1, "Attempting kernel_power_off: Temperature too high\n");
 352         kernel_power_off();
 353
 354         /*
 355          * Worst of the worst case trigger emergency restart
 356          */
 357         WARN(1, "Attempting emergency_restart: Temperature too high\n");
 358         emergency_restart();
 359 }
 360
 361 static DECLARE_DELAYED_WORK(thermal_emergency_poweroff_work,
 362                             thermal_emergency_poweroff_func);
 363
 364 /**
 365  * thermal_emergency_poweroff - Trigger an emergency system poweroff
 366  *
 367  * This may be called from any critical situation to trigger a system shutdown
 368  * after a known period of time. By default this is not scheduled.
 369  */
 370 static void thermal_emergency_poweroff(void)
 371 {
 372         int poweroff_delay_ms = CONFIG_THERMAL_EMERGENCY_POWEROFF_DELAY_MS;
 373         /*
 374          * poweroff_delay_ms must be a carefully profiled positive value.
 375          * Its a must for thermal_emergency_poweroff_work to be scheduled
 376          */
 377         if (poweroff_delay_ms <= 0)
 378                 return;
 379         schedule_delayed_work(&thermal_emergency_poweroff_work,
 380                               msecs_to_jiffies(poweroff_delay_ms));
 381 }
 382
 383 void thermal_zone_device_critical(struct thermal_zone_device *tz)
 384 {
 385         dev_emerg(&tz->device, "%s: critical temperature reached, "
 386                   "shutting down\n", tz->type);
 387
 388         mutex_lock(&poweroff_lock);
 389         if (!power_off_triggered) {
 390                 /*
 391                  * Queue a backup emergency shutdown in the event of
 392                  * orderly_poweroff failure
 393                  */
 394                 thermal_emergency_poweroff();
 395                 orderly_poweroff(true);
 396                 power_off_triggered = true;
 397         }
 398         mutex_unlock(&poweroff_lock);
 399 }
 400 EXPORT_SYMBOL(thermal_zone_device_critical);
 401
 402 static void handle_critical_trips(struct thermal_zone_device *tz,
 403                                   int trip, enum thermal_trip_type trip_type)
 404 {
 405         int trip_temp;
 406
 407         tz->ops->get_trip_temp(tz, trip, &trip_temp);
 408
 409         /* If we have not crossed the trip_temp, we do not care. */
 410         if (trip_temp <= 0 || tz->temperature < trip_temp)
 411                 return;
 412
 413         trace_thermal_zone_trip(tz, trip, trip_type);
 414
 415         if (tz->ops->notify)
 416                 tz->ops->notify(tz, trip, trip_type);
 417
 418         if (trip_type == THERMAL_TRIP_HOT && tz->ops->hot)
 419                 tz->ops->hot(tz);
 420         else if (trip_type == THERMAL_TRIP_CRITICAL)
 421                 tz->ops->critical(tz);
 422 }
 423
 424 static void handle_thermal_trip(struct thermal_zone_device *tz, int trip)
 425 {
 426         enum thermal_trip_type type;
 427         int trip_temp, hyst = 0;
 428
 429         /* Ignore disabled trip points */
 430         if (test_bit(trip, &tz->trips_disabled))
 431                 return;
 432
 433         tz->ops->get_trip_temp(tz, trip, &trip_temp);
 434         tz->ops->get_trip_type(tz, trip, &type);
 435         if (tz->ops->get_trip_hyst)
 436                 tz->ops->get_trip_hyst(tz, trip, &hyst);
 437
 438         if (tz->last_temperature != THERMAL_TEMP_INVALID) {
 439                 if (tz->last_temperature < trip_temp &&
 440                     tz->temperature >= trip_temp)
 441                         thermal_notify_tz_trip_up(tz->id, trip);
 442                 if (tz->last_temperature >= trip_temp &&
 443                     tz->temperature < (trip_temp - hyst))
 444                         thermal_notify_tz_trip_down(tz->id, trip);
 445         }
 446
 447         if (type == THERMAL_TRIP_CRITICAL || type == THERMAL_TRIP_HOT)
 448                 handle_critical_trips(tz, trip, type);
 449         else
 450                 handle_non_critical_trips(tz, trip);
 451         /*
 452          * Alright, we handled this trip successfully.
 453          * So, start monitoring again.
 454          */
 455         monitor_thermal_zone(tz);
 456 }
 457
 458 static void update_temperature(struct thermal_zone_device *tz)
 459 {
 460         int temp, ret;
 461
 462         ret = thermal_zone_get_temp(tz, &temp);
 463         if (ret) {
 464                 if (ret != -EAGAIN)
 465                         dev_warn(&tz->device,
 466                                  "failed to read out thermal zone (%d)\n",
 467                                  ret);
 468                 return;
 469         }
 470
 471         mutex_lock(&tz->lock);
 472         tz->last_temperature = tz->temperature;
 473         tz->temperature = temp;
 474         mutex_unlock(&tz->lock);
 475
 476         trace_thermal_temperature(tz);
 477
 478         thermal_genl_sampling_temp(tz->id, temp);
 479 }
 480
 481 static void thermal_zone_device_init(struct thermal_zone_device *tz)
 482 {
 483         struct thermal_instance *pos;
 484         tz->temperature = THERMAL_TEMP_INVALID;
 485         list_for_each_entry(pos, &tz->thermal_instances, tz_node)
 486                 pos->initialized = false;
 487 }
 488
 489 static void thermal_zone_device_reset(struct thermal_zone_device *tz)
 490 {
 491         tz->passive = 0;
 492         thermal_zone_device_init(tz);
 493 }
 494
 495 static int thermal_zone_device_set_mode(struct thermal_zone_device *tz,
 496                                         enum thermal_device_mode mode)
 497 {
 498         int ret = 0;
 499
 500         mutex_lock(&tz->lock);
 501
 502         /* do nothing if mode isn't changing */
 503         if (mode == tz->mode) {
 504                 mutex_unlock(&tz->lock);
 505
 506                 return ret;
 507         }
 508
 509         if (tz->ops->change_mode)
 510                 ret = tz->ops->change_mode(tz, mode);
 511
 512         if (!ret)
 513                 tz->mode = mode;
 514
 515         mutex_unlock(&tz->lock);
 516
 517         thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
 518
 519         if (mode == THERMAL_DEVICE_ENABLED)
 520                 thermal_notify_tz_enable(tz->id);
 521         else
 522                 thermal_notify_tz_disable(tz->id);
 523
 524         return ret;
 525 }
 526
 527 int thermal_zone_device_enable(struct thermal_zone_device *tz)
 528 {
 529         return thermal_zone_device_set_mode(tz, THERMAL_DEVICE_ENABLED);
 530 }
 531 EXPORT_SYMBOL_GPL(thermal_zone_device_enable);
 532
 533 int thermal_zone_device_disable(struct thermal_zone_device *tz)
 534 {
 535         return thermal_zone_device_set_mode(tz, THERMAL_DEVICE_DISABLED);
 536 }
 537 EXPORT_SYMBOL_GPL(thermal_zone_device_disable);
 538
 539 int thermal_zone_device_is_enabled(struct thermal_zone_device *tz)
 540 {
 541         enum thermal_device_mode mode;
 542
 543         mutex_lock(&tz->lock);
 544
 545         mode = tz->mode;
 546
 547         mutex_unlock(&tz->lock);
 548
 549         return mode == THERMAL_DEVICE_ENABLED;
 550 }
 551
 552 void thermal_zone_device_update(struct thermal_zone_device *tz,
 553                                 enum thermal_notify_event event)
 554 {
 555         int count;
 556
 557         if (should_stop_polling(tz))
 558                 return;
 559
 560         if (atomic_read(&in_suspend))
 561                 return;
 562
 563         if (WARN_ONCE(!tz->ops->get_temp, "'%s' must not be called without "
 564                       "'get_temp' ops set\n", __func__))
 565                 return;
 566
 567         update_temperature(tz);
 568
 569         thermal_zone_set_trips(tz);
 570
 571         tz->notify_event = event;
 572
 573         for (count = 0; count < tz->trips; count++)
 574                 handle_thermal_trip(tz, count);
 575 }
 576 EXPORT_SYMBOL_GPL(thermal_zone_device_update);
 577
 578 /**
 579  * thermal_notify_framework - Sensor drivers use this API to notify framework
 580  * @tz:         thermal zone device
 581  * @trip:       indicates which trip point has been crossed
 582  *
 583  * This function handles the trip events from sensor drivers. It starts
 584  * throttling the cooling devices according to the policy configured.
 585  * For CRITICAL and HOT trip points, this notifies the respective drivers,
 586  * and does actual throttling for other trip points i.e ACTIVE and PASSIVE.
 587  * The throttling policy is based on the configured platform data; if no
 588  * platform data is provided, this uses the step_wise throttling policy.
 589  */
 590 void thermal_notify_framework(struct thermal_zone_device *tz, int trip)
 591 {
 592         handle_thermal_trip(tz, trip);
 593 }
 594 EXPORT_SYMBOL_GPL(thermal_notify_framework);
 595
 596 static void thermal_zone_device_check(struct work_struct *work)
 597 {
 598         struct thermal_zone_device *tz = container_of(work, struct
 599                                                       thermal_zone_device,
 600                                                       poll_queue.work);
 601         thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
 602 }
 603
 604 void thermal_zone_device_rebind_exception(struct thermal_zone_device *tz,
 605                                           const char *cdev_type, size_t size)
 606 {
 607         struct thermal_cooling_device *cdev = NULL;
 608
 609         mutex_lock(&thermal_list_lock);
 610         list_for_each_entry(cdev, &thermal_cdev_list, node) {
 611                 /* skip non matching cdevs */
 612                 if (strncmp(cdev_type, cdev->type, size))
 613                         continue;
 614
 615                 /* re binding the exception matching the type pattern */
 616                 thermal_zone_bind_cooling_device(tz, THERMAL_TRIPS_NONE, cdev,
 617                                                  THERMAL_NO_LIMIT,
 618                                                  THERMAL_NO_LIMIT,
 619                                                  THERMAL_WEIGHT_DEFAULT);
 620         }
 621         mutex_unlock(&thermal_list_lock);
 622 }
 623
 624 int for_each_thermal_governor(int (*cb)(struct thermal_governor *, void *),
 625                               void *data)
 626 {
 627         struct thermal_governor *gov;
 628         int ret = 0;
 629
 630         mutex_lock(&thermal_governor_lock);
 631         list_for_each_entry(gov, &thermal_governor_list, governor_list) {
 632                 ret = cb(gov, data);
 633                 if (ret)
 634                         break;
 635         }
 636         mutex_unlock(&thermal_governor_lock);
 637
 638         return ret;
 639 }
 640
 641 int for_each_thermal_cooling_device(int (*cb)(struct thermal_cooling_device *,
 642                                               void *), void *data)
 643 {
 644         struct thermal_cooling_device *cdev;
 645         int ret = 0;
 646
 647         mutex_lock(&thermal_list_lock);
 648         list_for_each_entry(cdev, &thermal_cdev_list, node) {
 649                 ret = cb(cdev, data);
 650                 if (ret)
 651                         break;
 652         }
 653         mutex_unlock(&thermal_list_lock);
 654
 655         return ret;
 656 }
 657
 658 int for_each_thermal_zone(int (*cb)(struct thermal_zone_device *, void *),
 659                           void *data)
 660 {
 661         struct thermal_zone_device *tz;
 662         int ret = 0;
 663
 664         mutex_lock(&thermal_list_lock);
 665         list_for_each_entry(tz, &thermal_tz_list, node) {
 666                 ret = cb(tz, data);
 667                 if (ret)
 668                         break;
 669         }
 670         mutex_unlock(&thermal_list_lock);
 671
 672         return ret;
 673 }
 674
 675 struct thermal_zone_device *thermal_zone_get_by_id(int id)
 676 {
 677         struct thermal_zone_device *tz, *match = NULL;
 678
 679         mutex_lock(&thermal_list_lock);
 680         list_for_each_entry(tz, &thermal_tz_list, node) {
 681                 if (tz->id == id) {
 682                         match = tz;
 683                         break;
 684                 }
 685         }
 686         mutex_unlock(&thermal_list_lock);
 687
 688         return match;
 689 }
 690
 691 void thermal_zone_device_unbind_exception(struct thermal_zone_device *tz,
 692                                           const char *cdev_type, size_t size)
 693 {
 694         struct thermal_cooling_device *cdev = NULL;
 695
 696         mutex_lock(&thermal_list_lock);
 697         list_for_each_entry(cdev, &thermal_cdev_list, node) {
 698                 /* skip non matching cdevs */
 699                 if (strncmp(cdev_type, cdev->type, size))
 700                         continue;
 701                 /* unbinding the exception matching the type pattern */
 702                 thermal_zone_unbind_cooling_device(tz, THERMAL_TRIPS_NONE,
 703                                                    cdev);
 704         }
 705         mutex_unlock(&thermal_list_lock);
 706 }
 707
 708 /*
 709  * Device management section: cooling devices, zones devices, and binding
 710  *
 711  * Set of functions provided by the thermal core for:
 712  * - cooling devices lifecycle: registration, unregistration,
 713  *                              binding, and unbinding.
 714  * - thermal zone devices lifecycle: registration, unregistration,
 715  *                                   binding, and unbinding.
 716  */
 717
 718 /**
 719  * thermal_zone_bind_cooling_device() - bind a cooling device to a thermal zone
 720  * @tz:         pointer to struct thermal_zone_device
 721  * @trip:       indicates which trip point the cooling devices is
 722  *              associated with in this thermal zone.
 723  * @cdev:       pointer to struct thermal_cooling_device
 724  * @upper:      the Maximum cooling state for this trip point.
 725  *              THERMAL_NO_LIMIT means no upper limit,
 726  *              and the cooling device can be in max_state.
 727  * @lower:      the Minimum cooling state can be used for this trip point.
 728  *              THERMAL_NO_LIMIT means no lower limit,
 729  *              and the cooling device can be in cooling state 0.
 730  * @weight:     The weight of the cooling device to be bound to the
 731  *              thermal zone. Use THERMAL_WEIGHT_DEFAULT for the
 732  *              default value
 733  *
 734  * This interface function bind a thermal cooling device to the certain trip
 735  * point of a thermal zone device.
 736  * This function is usually called in the thermal zone device .bind callback.
 737  *
 738  * Return: 0 on success, the proper error value otherwise.
 739  */
 740 int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz,
 741                                      int trip,
 742                                      struct thermal_cooling_device *cdev,
 743                                      unsigned long upper, unsigned long lower,
 744                                      unsigned int weight)
 745 {
 746         struct thermal_instance *dev;
 747         struct thermal_instance *pos;
 748         struct thermal_zone_device *pos1;
 749         struct thermal_cooling_device *pos2;
 750         unsigned long max_state;
 751         int result, ret;
 752
 753         if (trip >= tz->trips || (trip < 0 && trip != THERMAL_TRIPS_NONE))
 754                 return -EINVAL;
 755
 756         list_for_each_entry(pos1, &thermal_tz_list, node) {
 757                 if (pos1 == tz)
 758                         break;
 759         }
 760         list_for_each_entry(pos2, &thermal_cdev_list, node) {
 761                 if (pos2 == cdev)
 762                         break;
 763         }
 764
 765         if (tz != pos1 || cdev != pos2)
 766                 return -EINVAL;
 767
 768         ret = cdev->ops->get_max_state(cdev, &max_state);
 769         if (ret)
 770                 return ret;
 771
 772         /* lower default 0, upper default max_state */
 773         lower = lower == THERMAL_NO_LIMIT ? 0 : lower;
 774         upper = upper == THERMAL_NO_LIMIT ? max_state : upper;
 775
 776         if (lower > upper || upper > max_state)
 777                 return -EINVAL;
 778
 779         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 780         if (!dev)
 781                 return -ENOMEM;
 782         dev->tz = tz;
 783         dev->cdev = cdev;
 784         dev->trip = trip;
 785         dev->upper = upper;
 786         dev->lower = lower;
 787         dev->target = THERMAL_NO_TARGET;
 788         dev->weight = weight;
 789
 790         result = ida_simple_get(&tz->ida, 0, 0, GFP_KERNEL);
 791         if (result < 0)
 792                 goto free_mem;
 793
 794         dev->id = result;
 795         sprintf(dev->name, "cdev%d", dev->id);
 796         result =
 797             sysfs_create_link(&tz->device.kobj, &cdev->device.kobj, dev->name);
 798         if (result)
 799                 goto release_ida;
 800
 801         sprintf(dev->attr_name, "cdev%d_trip_point", dev->id);
 802         sysfs_attr_init(&dev->attr.attr);
 803         dev->attr.attr.name = dev->attr_name;
 804         dev->attr.attr.mode = 0444;
 805         dev->attr.show = trip_point_show;
 806         result = device_create_file(&tz->device, &dev->attr);
 807         if (result)
 808                 goto remove_symbol_link;
 809
 810         sprintf(dev->weight_attr_name, "cdev%d_weight", dev->id);
 811         sysfs_attr_init(&dev->weight_attr.attr);
 812         dev->weight_attr.attr.name = dev->weight_attr_name;
 813         dev->weight_attr.attr.mode = S_IWUSR | S_IRUGO;
 814         dev->weight_attr.show = weight_show;
 815         dev->weight_attr.store = weight_store;
 816         result = device_create_file(&tz->device, &dev->weight_attr);
 817         if (result)
 818                 goto remove_trip_file;
 819
 820         mutex_lock(&tz->lock);
 821         mutex_lock(&cdev->lock);
 822         list_for_each_entry(pos, &tz->thermal_instances, tz_node)
 823                 if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
 824                         result = -EEXIST;
 825                         break;
 826                 }
 827         if (!result) {
 828                 list_add_tail(&dev->tz_node, &tz->thermal_instances);
 829                 list_add_tail(&dev->cdev_node, &cdev->thermal_instances);
 830                 atomic_set(&tz->need_update, 1);
 831         }
 832         mutex_unlock(&cdev->lock);
 833         mutex_unlock(&tz->lock);
 834
 835         if (!result)
 836                 return 0;
 837
 838         device_remove_file(&tz->device, &dev->weight_attr);
 839 remove_trip_file:
 840         device_remove_file(&tz->device, &dev->attr);
 841 remove_symbol_link:
 842         sysfs_remove_link(&tz->device.kobj, dev->name);
 843 release_ida:
 844         ida_simple_remove(&tz->ida, dev->id);
 845 free_mem:
 846         kfree(dev);
 847         return result;
 848 }
 849 EXPORT_SYMBOL_GPL(thermal_zone_bind_cooling_device);
 850
 851 /**
 852  * thermal_zone_unbind_cooling_device() - unbind a cooling device from a
 853  *                                        thermal zone.
 854  * @tz:         pointer to a struct thermal_zone_device.
 855  * @trip:       indicates which trip point the cooling devices is
 856  *              associated with in this thermal zone.
 857  * @cdev:       pointer to a struct thermal_cooling_device.
 858  *
 859  * This interface function unbind a thermal cooling device from the certain
 860  * trip point of a thermal zone device.
 861  * This function is usually called in the thermal zone device .unbind callback.
 862  *
 863  * Return: 0 on success, the proper error value otherwise.
 864  */
 865 int thermal_zone_unbind_cooling_device(struct thermal_zone_device *tz,
 866                                        int trip,
 867                                        struct thermal_cooling_device *cdev)
 868 {
 869         struct thermal_instance *pos, *next;
 870
 871         mutex_lock(&tz->lock);
 872         mutex_lock(&cdev->lock);
 873         list_for_each_entry_safe(pos, next, &tz->thermal_instances, tz_node) {
 874                 if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
 875                         list_del(&pos->tz_node);
 876                         list_del(&pos->cdev_node);
 877                         mutex_unlock(&cdev->lock);
 878                         mutex_unlock(&tz->lock);
 879                         goto unbind;
 880                 }
 881         }
 882         mutex_unlock(&cdev->lock);
 883         mutex_unlock(&tz->lock);
 884
 885         return -ENODEV;
 886
 887 unbind:
 888         device_remove_file(&tz->device, &pos->weight_attr);
 889         device_remove_file(&tz->device, &pos->attr);
 890         sysfs_remove_link(&tz->device.kobj, pos->name);
 891         ida_simple_remove(&tz->ida, pos->id);
 892         kfree(pos);
 893         return 0;
 894 }
 895 EXPORT_SYMBOL_GPL(thermal_zone_unbind_cooling_device);
 896
 897 static void thermal_release(struct device *dev)
 898 {
 899         struct thermal_zone_device *tz;
 900         struct thermal_cooling_device *cdev;
 901
 902         if (!strncmp(dev_name(dev), "thermal_zone",
 903                      sizeof("thermal_zone") - 1)) {
 904                 tz = to_thermal_zone(dev);
 905                 thermal_zone_destroy_device_groups(tz);
 906                 kfree(tz);
 907         } else if (!strncmp(dev_name(dev), "cooling_device",
 908                             sizeof("cooling_device") - 1)) {
 909                 cdev = to_cooling_device(dev);
 910                 kfree(cdev);
 911         }
 912 }
 913
 914 static struct class thermal_class = {
 915         .name = "thermal",
 916         .dev_release = thermal_release,
 917 };
 918
 919 static inline
 920 void print_bind_err_msg(struct thermal_zone_device *tz,
 921                         struct thermal_cooling_device *cdev, int ret)
 922 {
 923         dev_err(&tz->device, "binding zone %s with cdev %s failed:%d\n",
 924                 tz->type, cdev->type, ret);
 925 }
 926
 927 static void __bind(struct thermal_zone_device *tz, int mask,
 928                    struct thermal_cooling_device *cdev,
 929                    unsigned long *limits,
 930                    unsigned int weight)
 931 {
 932         int i, ret;
 933
 934         for (i = 0; i < tz->trips; i++) {
 935                 if (mask & (1 << i)) {
 936                         unsigned long upper, lower;
 937
 938                         upper = THERMAL_NO_LIMIT;
 939                         lower = THERMAL_NO_LIMIT;
 940                         if (limits) {
 941                                 lower = limits[i * 2];
 942                                 upper = limits[i * 2 + 1];
 943                         }
 944                         ret = thermal_zone_bind_cooling_device(tz, i, cdev,
 945                                                                upper, lower,
 946                                                                weight);
 947                         if (ret)
 948                                 print_bind_err_msg(tz, cdev, ret);
 949                 }
 950         }
 951 }
 952
 953 static void bind_cdev(struct thermal_cooling_device *cdev)
 954 {
 955         int i, ret;
 956         const struct thermal_zone_params *tzp;
 957         struct thermal_zone_device *pos = NULL;
 958
 959         mutex_lock(&thermal_list_lock);
 960
 961         list_for_each_entry(pos, &thermal_tz_list, node) {
 962                 if (!pos->tzp && !pos->ops->bind)
 963                         continue;
 964
 965                 if (pos->ops->bind) {
 966                         ret = pos->ops->bind(pos, cdev);
 967                         if (ret)
 968                                 print_bind_err_msg(pos, cdev, ret);
 969                         continue;
 970                 }
 971
 972                 tzp = pos->tzp;
 973                 if (!tzp || !tzp->tbp)
 974                         continue;
 975
 976                 for (i = 0; i < tzp->num_tbps; i++) {
 977                         if (tzp->tbp[i].cdev || !tzp->tbp[i].match)
 978                                 continue;
 979                         if (tzp->tbp[i].match(pos, cdev))
 980                                 continue;
 981                         tzp->tbp[i].cdev = cdev;
 982                         __bind(pos, tzp->tbp[i].trip_mask, cdev,
 983                                tzp->tbp[i].binding_limits,
 984                                tzp->tbp[i].weight);
 985                 }
 986         }
 987
 988         mutex_unlock(&thermal_list_lock);
 989 }
 990
 991 /**
 992  * __thermal_cooling_device_register() - register a new thermal cooling device
 993  * @np:         a pointer to a device tree node.
 994  * @type:       the thermal cooling device type.
 995  * @devdata:    device private data.
 996  * @ops:                standard thermal cooling devices callbacks.
 997  *
 998  * This interface function adds a new thermal cooling device (fan/processor/...)
 999  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
1000  * to all the thermal zone devices registered at the same time.
1001  * It also gives the opportunity to link the cooling device to a device tree
1002  * node, so that it can be bound to a thermal zone created out of device tree.
1003  *
1004  * Return: a pointer to the created struct thermal_cooling_device or an
1005  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
1006  */
1007 static struct thermal_cooling_device *
1008 __thermal_cooling_device_register(struct device_node *np,
1009                                   const char *type, void *devdata,
1010                                   const struct thermal_cooling_device_ops *ops)
1011 {
1012         struct thermal_cooling_device *cdev;
1013         struct thermal_zone_device *pos = NULL;
1014         int result;
1015
1016         if (type && strlen(type) >= THERMAL_NAME_LENGTH)
1017                 return ERR_PTR(-EINVAL);
1018
1019         if (!ops || !ops->get_max_state || !ops->get_cur_state ||
1020             !ops->set_cur_state)
1021                 return ERR_PTR(-EINVAL);
1022
1023         cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
1024         if (!cdev)
1025                 return ERR_PTR(-ENOMEM);
1026
1027         result = ida_simple_get(&thermal_cdev_ida, 0, 0, GFP_KERNEL);
1028         if (result < 0) {
1029                 kfree(cdev);
1030                 return ERR_PTR(result);
1031         }
1032
1033         cdev->id = result;
1034         strlcpy(cdev->type, type ? : "", sizeof(cdev->type));
1035         mutex_init(&cdev->lock);
1036         INIT_LIST_HEAD(&cdev->thermal_instances);
1037         cdev->np = np;
1038         cdev->ops = ops;
1039         cdev->updated = false;
1040         cdev->device.class = &thermal_class;
1041         cdev->devdata = devdata;
1042         thermal_cooling_device_setup_sysfs(cdev);
1043         dev_set_name(&cdev->device, "cooling_device%d", cdev->id);
1044         result = device_register(&cdev->device);
1045         if (result) {
1046                 ida_simple_remove(&thermal_cdev_ida, cdev->id);
1047                 put_device(&cdev->device);
1048                 return ERR_PTR(result);
1049         }
1050
1051         /* Add 'this' new cdev to the global cdev list */
1052         mutex_lock(&thermal_list_lock);
1053         list_add(&cdev->node, &thermal_cdev_list);
1054         mutex_unlock(&thermal_list_lock);
1055
1056         /* Update binding information for 'this' new cdev */
1057         bind_cdev(cdev);
1058
1059         mutex_lock(&thermal_list_lock);
1060         list_for_each_entry(pos, &thermal_tz_list, node)
1061                 if (atomic_cmpxchg(&pos->need_update, 1, 0))
1062                         thermal_zone_device_update(pos,
1063                                                    THERMAL_EVENT_UNSPECIFIED);
1064         mutex_unlock(&thermal_list_lock);
1065
1066         return cdev;
1067 }
1068
1069 /**
1070  * thermal_cooling_device_register() - register a new thermal cooling device
1071  * @type:       the thermal cooling device type.
1072  * @devdata:    device private data.
1073  * @ops:                standard thermal cooling devices callbacks.
1074  *
1075  * This interface function adds a new thermal cooling device (fan/processor/...)
1076  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
1077  * to all the thermal zone devices registered at the same time.
1078  *
1079  * Return: a pointer to the created struct thermal_cooling_device or an
1080  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
1081  */
1082 struct thermal_cooling_device *
1083 thermal_cooling_device_register(const char *type, void *devdata,
1084                                 const struct thermal_cooling_device_ops *ops)
1085 {
1086         return __thermal_cooling_device_register(NULL, type, devdata, ops);
1087 }
1088 EXPORT_SYMBOL_GPL(thermal_cooling_device_register);
1089
1090 /**
1091  * thermal_of_cooling_device_register() - register an OF thermal cooling device
1092  * @np:         a pointer to a device tree node.
1093  * @type:       the thermal cooling device type.
1094  * @devdata:    device private data.
1095  * @ops:                standard thermal cooling devices callbacks.
1096  *
1097  * This function will register a cooling device with device tree node reference.
1098  * This interface function adds a new thermal cooling device (fan/processor/...)
1099  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
1100  * to all the thermal zone devices registered at the same time.
1101  *
1102  * Return: a pointer to the created struct thermal_cooling_device or an
1103  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
1104  */
1105 struct thermal_cooling_device *
1106 thermal_of_cooling_device_register(struct device_node *np,
1107                                    const char *type, void *devdata,
1108                                    const struct thermal_cooling_device_ops *ops)
1109 {
1110         return __thermal_cooling_device_register(np, type, devdata, ops);
1111 }
1112 EXPORT_SYMBOL_GPL(thermal_of_cooling_device_register);
1113
1114 static void thermal_cooling_device_release(struct device *dev, void *res)
1115 {
1116         thermal_cooling_device_unregister(
1117                                 *(struct thermal_cooling_device **)res);
1118 }
1119
1120 /**
1121  * devm_thermal_of_cooling_device_register() - register an OF thermal cooling
1122  *                                             device
1123  * @dev:        a valid struct device pointer of a sensor device.
1124  * @np:         a pointer to a device tree node.
1125  * @type:       the thermal cooling device type.
1126  * @devdata:    device private data.
1127  * @ops:        standard thermal cooling devices callbacks.
1128  *
1129  * This function will register a cooling device with device tree node reference.
1130  * This interface function adds a new thermal cooling device (fan/processor/...)
1131  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
1132  * to all the thermal zone devices registered at the same time.
1133  *
1134  * Return: a pointer to the created struct thermal_cooling_device or an
1135  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
1136  */
1137 struct thermal_cooling_device *
1138 devm_thermal_of_cooling_device_register(struct device *dev,
1139                                 struct device_node *np,
1140                                 char *type, void *devdata,
1141                                 const struct thermal_cooling_device_ops *ops)
1142 {
1143         struct thermal_cooling_device **ptr, *tcd;
1144
1145         ptr = devres_alloc(thermal_cooling_device_release, sizeof(*ptr),
1146                            GFP_KERNEL);
1147         if (!ptr)
1148                 return ERR_PTR(-ENOMEM);
1149
1150         tcd = __thermal_cooling_device_register(np, type, devdata, ops);
1151         if (IS_ERR(tcd)) {
1152                 devres_free(ptr);
1153                 return tcd;
1154         }
1155
1156         *ptr = tcd;
1157         devres_add(dev, ptr);
1158
1159         return tcd;
1160 }
1161 EXPORT_SYMBOL_GPL(devm_thermal_of_cooling_device_register);
1162
1163 static void __unbind(struct thermal_zone_device *tz, int mask,
1164                      struct thermal_cooling_device *cdev)
1165 {
1166         int i;
1167
1168         for (i = 0; i < tz->trips; i++)
1169                 if (mask & (1 << i))
1170                         thermal_zone_unbind_cooling_device(tz, i, cdev);
1171 }
1172
1173 /**
1174  * thermal_cooling_device_unregister - removes a thermal cooling device
1175  * @cdev:       the thermal cooling device to remove.
1176  *
1177  * thermal_cooling_device_unregister() must be called when a registered
1178  * thermal cooling device is no longer needed.
1179  */
1180 void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev)
1181 {
1182         int i;
1183         const struct thermal_zone_params *tzp;
1184         struct thermal_zone_device *tz;
1185         struct thermal_cooling_device *pos = NULL;
1186
1187         if (!cdev)
1188                 return;
1189
1190         mutex_lock(&thermal_list_lock);
1191         list_for_each_entry(pos, &thermal_cdev_list, node)
1192                 if (pos == cdev)
1193                         break;
1194         if (pos != cdev) {
1195                 /* thermal cooling device not found */
1196                 mutex_unlock(&thermal_list_lock);
1197                 return;
1198         }
1199         list_del(&cdev->node);
1200
1201         /* Unbind all thermal zones associated with 'this' cdev */
1202         list_for_each_entry(tz, &thermal_tz_list, node) {
1203                 if (tz->ops->unbind) {
1204                         tz->ops->unbind(tz, cdev);
1205                         continue;
1206                 }
1207
1208                 if (!tz->tzp || !tz->tzp->tbp)
1209                         continue;
1210
1211                 tzp = tz->tzp;
1212                 for (i = 0; i < tzp->num_tbps; i++) {
1213                         if (tzp->tbp[i].cdev == cdev) {
1214                                 __unbind(tz, tzp->tbp[i].trip_mask, cdev);
1215                                 tzp->tbp[i].cdev = NULL;
1216                         }
1217                 }
1218         }
1219
1220         mutex_unlock(&thermal_list_lock);
1221
1222         ida_simple_remove(&thermal_cdev_ida, cdev->id);
1223         device_del(&cdev->device);
1224         thermal_cooling_device_destroy_sysfs(cdev);
1225         put_device(&cdev->device);
1226 }
1227 EXPORT_SYMBOL_GPL(thermal_cooling_device_unregister);
1228
1229 static void bind_tz(struct thermal_zone_device *tz)
1230 {
1231         int i, ret;
1232         struct thermal_cooling_device *pos = NULL;
1233         const struct thermal_zone_params *tzp = tz->tzp;
1234
1235         if (!tzp && !tz->ops->bind)
1236                 return;
1237
1238         mutex_lock(&thermal_list_lock);
1239
1240         /* If there is ops->bind, try to use ops->bind */
1241         if (tz->ops->bind) {
1242                 list_for_each_entry(pos, &thermal_cdev_list, node) {
1243                         ret = tz->ops->bind(tz, pos);
1244                         if (ret)
1245                                 print_bind_err_msg(tz, pos, ret);
1246                 }
1247                 goto exit;
1248         }
1249
1250         if (!tzp || !tzp->tbp)
1251                 goto exit;
1252
1253         list_for_each_entry(pos, &thermal_cdev_list, node) {
1254                 for (i = 0; i < tzp->num_tbps; i++) {
1255                         if (tzp->tbp[i].cdev || !tzp->tbp[i].match)
1256                                 continue;
1257                         if (tzp->tbp[i].match(tz, pos))
1258                                 continue;
1259                         tzp->tbp[i].cdev = pos;
1260                         __bind(tz, tzp->tbp[i].trip_mask, pos,
1261                                tzp->tbp[i].binding_limits,
1262                                tzp->tbp[i].weight);
1263                 }
1264         }
1265 exit:
1266         mutex_unlock(&thermal_list_lock);
1267 }
1268
1269 /**
1270  * thermal_zone_device_register() - register a new thermal zone device
1271  * @type:       the thermal zone device type
1272  * @trips:      the number of trip points the thermal zone support
1273  * @mask:       a bit string indicating the writeablility of trip points
1274  * @devdata:    private device data
1275  * @ops:        standard thermal zone device callbacks
1276  * @tzp:        thermal zone platform parameters
1277  * @passive_delay: number of milliseconds to wait between polls when
1278  *                 performing passive cooling
1279  * @polling_delay: number of milliseconds to wait between polls when checking
1280  *                 whether trip points have been crossed (0 for interrupt
1281  *                 driven systems)
1282  *
1283  * This interface function adds a new thermal zone device (sensor) to
1284  * /sys/class/thermal folder as thermal_zone[0-*]. It tries to bind all the
1285  * thermal cooling devices registered at the same time.
1286  * thermal_zone_device_unregister() must be called when the device is no
1287  * longer needed. The passive cooling depends on the .get_trend() return value.
1288  *
1289  * Return: a pointer to the created struct thermal_zone_device or an
1290  * in case of error, an ERR_PTR. Caller must check return value with
1291  * IS_ERR*() helpers.
1292  */
1293 struct thermal_zone_device *
1294 thermal_zone_device_register(const char *type, int trips, int mask,
1295                              void *devdata, struct thermal_zone_device_ops *ops,
1296                              struct thermal_zone_params *tzp, int passive_delay,
1297                              int polling_delay)
1298 {
1299         struct thermal_zone_device *tz;
1300         enum thermal_trip_type trip_type;
1301         int trip_temp;
1302         int id;
1303         int result;
1304         int count;
1305         struct thermal_governor *governor;
1306
1307         if (!type || strlen(type) == 0) {
1308                 pr_err("Error: No thermal zone type defined\n");
1309                 return ERR_PTR(-EINVAL);
1310         }
1311
1312         if (type && strlen(type) >= THERMAL_NAME_LENGTH) {
1313                 pr_err("Error: Thermal zone name (%s) too long, should be under %d chars\n",
1314                        type, THERMAL_NAME_LENGTH);
1315                 return ERR_PTR(-EINVAL);
1316         }
1317
1318         if (trips > THERMAL_MAX_TRIPS || trips < 0 || mask >> trips) {
1319                 pr_err("Error: Incorrect number of thermal trips\n");
1320                 return ERR_PTR(-EINVAL);
1321         }
1322
1323         if (!ops) {
1324                 pr_err("Error: Thermal zone device ops not defined\n");
1325                 return ERR_PTR(-EINVAL);
1326         }
1327
1328         if (trips > 0 && (!ops->get_trip_type || !ops->get_trip_temp))
1329                 return ERR_PTR(-EINVAL);
1330
1331         tz = kzalloc(sizeof(*tz), GFP_KERNEL);
1332         if (!tz)
1333                 return ERR_PTR(-ENOMEM);
1334
1335         INIT_LIST_HEAD(&tz->thermal_instances);
1336         ida_init(&tz->ida);
1337         mutex_init(&tz->lock);
1338         id = ida_simple_get(&thermal_tz_ida, 0, 0, GFP_KERNEL);
1339         if (id < 0) {
1340                 result = id;
1341                 goto free_tz;
1342         }
1343
1344         tz->id = id;
1345         strlcpy(tz->type, type, sizeof(tz->type));
1346
1347         if (!ops->critical)
1348                 ops->critical = thermal_zone_device_critical;
1349
1350         tz->ops = ops;
1351         tz->tzp = tzp;
1352         tz->device.class = &thermal_class;
1353         tz->devdata = devdata;
1354         tz->trips = trips;
1355         tz->passive_delay = passive_delay;
1356         tz->polling_delay = polling_delay;
1357
1358         /* sys I/F */
1359         /* Add nodes that are always present via .groups */
1360         result = thermal_zone_create_device_groups(tz, mask);
1361         if (result)
1362                 goto remove_id;
1363
1364         /* A new thermal zone needs to be updated anyway. */
1365         atomic_set(&tz->need_update, 1);
1366
1367         dev_set_name(&tz->device, "thermal_zone%d", tz->id);
1368         result = device_register(&tz->device);
1369         if (result)
1370                 goto release_device;
1371
1372         for (count = 0; count < trips; count++) {
1373                 if (tz->ops->get_trip_type(tz, count, &trip_type) ||
1374                     tz->ops->get_trip_temp(tz, count, &trip_temp) ||
1375                     !trip_temp)
1376                         set_bit(count, &tz->trips_disabled);
1377         }
1378
1379         /* Update 'this' zone's governor information */
1380         mutex_lock(&thermal_governor_lock);
1381
1382         if (tz->tzp)
1383                 governor = __find_governor(tz->tzp->governor_name);
1384         else
1385                 governor = def_governor;
1386
1387         result = thermal_set_governor(tz, governor);
1388         if (result) {
1389                 mutex_unlock(&thermal_governor_lock);
1390                 goto unregister;
1391         }
1392
1393         mutex_unlock(&thermal_governor_lock);
1394
1395         if (!tz->tzp || !tz->tzp->no_hwmon) {
1396                 result = thermal_add_hwmon_sysfs(tz);
1397                 if (result)
1398                         goto unregister;
1399         }
1400
1401         mutex_lock(&thermal_list_lock);
1402         list_add_tail(&tz->node, &thermal_tz_list);
1403         mutex_unlock(&thermal_list_lock);
1404
1405         /* Bind cooling devices for this zone */
1406         bind_tz(tz);
1407
1408         INIT_DELAYED_WORK(&tz->poll_queue, thermal_zone_device_check);
1409
1410         thermal_zone_device_reset(tz);
1411         /* Update the new thermal zone and mark it as already updated. */
1412         if (atomic_cmpxchg(&tz->need_update, 1, 0))
1413                 thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
1414
1415         thermal_notify_tz_create(tz->id, tz->type);
1416
1417         return tz;
1418
1419 unregister:
1420         device_del(&tz->device);
1421 release_device:
1422         put_device(&tz->device);
1423         tz = NULL;
1424 remove_id:
1425         ida_simple_remove(&thermal_tz_ida, id);
1426 free_tz:
1427         kfree(tz);
1428         return ERR_PTR(result);
1429 }
1430 EXPORT_SYMBOL_GPL(thermal_zone_device_register);
1431
1432 /**
1433  * thermal_device_unregister - removes the registered thermal zone device
1434  * @tz: the thermal zone device to remove
1435  */
1436 void thermal_zone_device_unregister(struct thermal_zone_device *tz)
1437 {
1438         int i, tz_id;
1439         const struct thermal_zone_params *tzp;
1440         struct thermal_cooling_device *cdev;
1441         struct thermal_zone_device *pos = NULL;
1442
1443         if (!tz)
1444                 return;
1445
1446         tzp = tz->tzp;
1447         tz_id = tz->id;
1448
1449         mutex_lock(&thermal_list_lock);
1450         list_for_each_entry(pos, &thermal_tz_list, node)
1451                 if (pos == tz)
1452                         break;
1453         if (pos != tz) {
1454                 /* thermal zone device not found */
1455                 mutex_unlock(&thermal_list_lock);
1456                 return;
1457         }
1458         list_del(&tz->node);
1459
1460         /* Unbind all cdevs associated with 'this' thermal zone */
1461         list_for_each_entry(cdev, &thermal_cdev_list, node) {
1462                 if (tz->ops->unbind) {
1463                         tz->ops->unbind(tz, cdev);
1464                         continue;
1465                 }
1466
1467                 if (!tzp || !tzp->tbp)
1468                         break;
1469
1470                 for (i = 0; i < tzp->num_tbps; i++) {
1471                         if (tzp->tbp[i].cdev == cdev) {
1472                                 __unbind(tz, tzp->tbp[i].trip_mask, cdev);
1473                                 tzp->tbp[i].cdev = NULL;
1474                         }
1475                 }
1476         }
1477
1478         mutex_unlock(&thermal_list_lock);
1479
1480         cancel_delayed_work_sync(&tz->poll_queue);
1481
1482         thermal_set_governor(tz, NULL);
1483
1484         thermal_remove_hwmon_sysfs(tz);
1485         ida_simple_remove(&thermal_tz_ida, tz->id);
1486         ida_destroy(&tz->ida);
1487         mutex_destroy(&tz->lock);
1488         device_unregister(&tz->device);
1489
1490         thermal_notify_tz_delete(tz_id);
1491 }
1492 EXPORT_SYMBOL_GPL(thermal_zone_device_unregister);
1493
1494 /**
1495  * thermal_zone_get_zone_by_name() - search for a zone and returns its ref
1496  * @name: thermal zone name to fetch the temperature
1497  *
1498  * When only one zone is found with the passed name, returns a reference to it.
1499  *
1500  * Return: On success returns a reference to an unique thermal zone with
1501  * matching name equals to @name, an ERR_PTR otherwise (-EINVAL for invalid
1502  * paramenters, -ENODEV for not found and -EEXIST for multiple matches).
1503  */
1504 struct thermal_zone_device *thermal_zone_get_zone_by_name(const char *name)
1505 {
1506         struct thermal_zone_device *pos = NULL, *ref = ERR_PTR(-EINVAL);
1507         unsigned int found = 0;
1508
1509         if (!name)
1510                 goto exit;
1511
1512         mutex_lock(&thermal_list_lock);
1513         list_for_each_entry(pos, &thermal_tz_list, node)
1514                 if (!strncasecmp(name, pos->type, THERMAL_NAME_LENGTH)) {
1515                         found++;
1516                         ref = pos;
1517                 }
1518         mutex_unlock(&thermal_list_lock);
1519
1520         /* nothing has been found, thus an error code for it */
1521         if (found == 0)
1522                 ref = ERR_PTR(-ENODEV);
1523         else if (found > 1)
1524         /* Success only when an unique zone is found */
1525                 ref = ERR_PTR(-EEXIST);
1526
1527 exit:
1528         return ref;
1529 }
1530 EXPORT_SYMBOL_GPL(thermal_zone_get_zone_by_name);
1531
1532 static int thermal_pm_notify(struct notifier_block *nb,
1533                              unsigned long mode, void *_unused)
1534 {
1535         struct thermal_zone_device *tz;
1536
1537         switch (mode) {
1538         case PM_HIBERNATION_PREPARE:
1539         case PM_RESTORE_PREPARE:
1540         case PM_SUSPEND_PREPARE:
1541                 atomic_set(&in_suspend, 1);
1542                 break;
1543         case PM_POST_HIBERNATION:
1544         case PM_POST_RESTORE:
1545         case PM_POST_SUSPEND:
1546                 atomic_set(&in_suspend, 0);
1547                 list_for_each_entry(tz, &thermal_tz_list, node) {
1548                         if (!thermal_zone_device_is_enabled(tz))
1549                                 continue;
1550
1551                         thermal_zone_device_init(tz);
1552                         thermal_zone_device_update(tz,
1553                                                    THERMAL_EVENT_UNSPECIFIED);
1554                 }
1555                 break;
1556         default:
1557                 break;
1558         }
1559         return 0;
1560 }
1561
1562 static struct notifier_block thermal_pm_nb = {
1563         .notifier_call = thermal_pm_notify,
1564 };
1565
1566 static int __init thermal_init(void)
1567 {
1568         int result;
1569
1570         result = thermal_netlink_init();
1571         if (result)
1572                 goto error;
1573
1574         result = thermal_register_governors();
1575         if (result)
1576                 goto error;
1577
1578         result = class_register(&thermal_class);
1579         if (result)
1580                 goto unregister_governors;
1581
1582         result = of_parse_thermal_zones();
1583         if (result)
1584                 goto unregister_class;
1585
1586         result = register_pm_notifier(&thermal_pm_nb);
1587         if (result)
1588                 pr_warn("Thermal: Can not register suspend notifier, return %d\n",
1589                         result);
1590
1591         return 0;
1592
1593 unregister_class:
1594         class_unregister(&thermal_class);
1595 unregister_governors:
1596         thermal_unregister_governors();
1597 error:
1598         ida_destroy(&thermal_tz_ida);
1599         ida_destroy(&thermal_cdev_ida);
1600         mutex_destroy(&thermal_list_lock);
1601         mutex_destroy(&thermal_governor_lock);
1602         mutex_destroy(&poweroff_lock);
1603         return result;
1604 }
1605 postcore_initcall(thermal_init);