drivers/acpi/thermal.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  acpi_thermal.c - ACPI Thermal Zone Driver ($Revision: 41 $)
   4  *
   5  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   6  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   7  *
   8  *  This driver fully implements the ACPI thermal policy as described in the
   9  *  ACPI 2.0 Specification.
  10  *
  11  *  TBD: 1. Implement passive cooling hysteresis.
  12  *       2. Enhance passive cooling (CPU) states/limit interface to support
  13  *          concepts of 'multiple limiters', upper/lower limits, etc.
  14  */
  15
  16 #define pr_fmt(fmt) "ACPI: thermal: " fmt
  17
  18 #include <linux/kernel.h>
  19 #include <linux/module.h>
  20 #include <linux/dmi.h>
  21 #include <linux/init.h>
  22 #include <linux/slab.h>
  23 #include <linux/types.h>
  24 #include <linux/jiffies.h>
  25 #include <linux/kmod.h>
  26 #include <linux/reboot.h>
  27 #include <linux/device.h>
  28 #include <linux/thermal.h>
  29 #include <linux/acpi.h>
  30 #include <linux/workqueue.h>
  31 #include <linux/uaccess.h>
  32 #include <linux/units.h>
  33
  34 #define ACPI_THERMAL_CLASS              "thermal_zone"
  35 #define ACPI_THERMAL_DEVICE_NAME        "Thermal Zone"
  36 #define ACPI_THERMAL_NOTIFY_TEMPERATURE 0x80
  37 #define ACPI_THERMAL_NOTIFY_THRESHOLDS  0x81
  38 #define ACPI_THERMAL_NOTIFY_DEVICES     0x82
  39 #define ACPI_THERMAL_NOTIFY_CRITICAL    0xF0
  40 #define ACPI_THERMAL_NOTIFY_HOT         0xF1
  41 #define ACPI_THERMAL_MODE_ACTIVE        0x00
  42
  43 #define ACPI_THERMAL_MAX_ACTIVE         10
  44 #define ACPI_THERMAL_MAX_LIMIT_STR_LEN  65
  45
  46 #define ACPI_TRIPS_CRITICAL     BIT(0)
  47 #define ACPI_TRIPS_HOT          BIT(1)
  48 #define ACPI_TRIPS_PASSIVE      BIT(2)
  49 #define ACPI_TRIPS_ACTIVE       BIT(3)
  50 #define ACPI_TRIPS_DEVICES      BIT(4)
  51
  52 #define ACPI_TRIPS_THRESHOLDS   (ACPI_TRIPS_PASSIVE | ACPI_TRIPS_ACTIVE)
  53
  54 #define ACPI_TRIPS_INIT         (ACPI_TRIPS_CRITICAL | ACPI_TRIPS_HOT | \
  55                                  ACPI_TRIPS_PASSIVE | ACPI_TRIPS_ACTIVE | \
  56                                  ACPI_TRIPS_DEVICES)
  57
  58 /*
  59  * This exception is thrown out in two cases:
  60  * 1.An invalid trip point becomes invalid or a valid trip point becomes invalid
  61  *   when re-evaluating the AML code.
  62  * 2.TODO: Devices listed in _PSL, _ALx, _TZD may change.
  63  *   We need to re-bind the cooling devices of a thermal zone when this occurs.
  64  */
  65 #define ACPI_THERMAL_TRIPS_EXCEPTION(flags, tz, str) \
  66 do { \
  67         if (flags != ACPI_TRIPS_INIT) \
  68                 acpi_handle_info(tz->device->handle, \
  69                         "ACPI thermal trip point %s changed\n" \
  70                         "Please report to linux-acpi@vger.kernel.org\n", str); \
  71 } while (0)
  72
  73 static int act;
  74 module_param(act, int, 0644);
  75 MODULE_PARM_DESC(act, "Disable or override all lowest active trip points.");
  76
  77 static int crt;
  78 module_param(crt, int, 0644);
  79 MODULE_PARM_DESC(crt, "Disable or lower all critical trip points.");
  80
  81 static int tzp;
  82 module_param(tzp, int, 0444);
  83 MODULE_PARM_DESC(tzp, "Thermal zone polling frequency, in 1/10 seconds.");
  84
  85 static int off;
  86 module_param(off, int, 0);
  87 MODULE_PARM_DESC(off, "Set to disable ACPI thermal support.");
  88
  89 static int psv;
  90 module_param(psv, int, 0644);
  91 MODULE_PARM_DESC(psv, "Disable or override all passive trip points.");
  92
  93 static struct workqueue_struct *acpi_thermal_pm_queue;
  94
  95 struct acpi_thermal_trip {
  96         unsigned long temperature;
  97         bool valid;
  98 };
  99
 100 struct acpi_thermal_passive {
 101         struct acpi_thermal_trip trip;
 102         struct acpi_handle_list devices;
 103         unsigned long tc1;
 104         unsigned long tc2;
 105         unsigned long tsp;
 106 };
 107
 108 struct acpi_thermal_active {
 109         struct acpi_thermal_trip trip;
 110         struct acpi_handle_list devices;
 111 };
 112
 113 struct acpi_thermal_trips {
 114         struct acpi_thermal_trip critical;
 115         struct acpi_thermal_trip hot;
 116         struct acpi_thermal_passive passive;
 117         struct acpi_thermal_active active[ACPI_THERMAL_MAX_ACTIVE];
 118 };
 119
 120 struct acpi_thermal {
 121         struct acpi_device *device;
 122         acpi_bus_id name;
 123         unsigned long temperature;
 124         unsigned long last_temperature;
 125         unsigned long polling_frequency;
 126         volatile u8 zombie;
 127         struct acpi_thermal_trips trips;
 128         struct thermal_trip *trip_table;
 129         struct acpi_handle_list devices;
 130         struct thermal_zone_device *thermal_zone;
 131         int kelvin_offset;      /* in millidegrees */
 132         struct work_struct thermal_check_work;
 133         struct mutex thermal_check_lock;
 134         refcount_t thermal_check_count;
 135 };
 136
 137 /* --------------------------------------------------------------------------
 138                              Thermal Zone Management
 139    -------------------------------------------------------------------------- */
 140
 141 static int acpi_thermal_get_temperature(struct acpi_thermal *tz)
 142 {
 143         acpi_status status = AE_OK;
 144         unsigned long long tmp;
 145
 146         if (!tz)
 147                 return -EINVAL;
 148
 149         tz->last_temperature = tz->temperature;
 150
 151         status = acpi_evaluate_integer(tz->device->handle, "_TMP", NULL, &tmp);
 152         if (ACPI_FAILURE(status))
 153                 return -ENODEV;
 154
 155         tz->temperature = tmp;
 156
 157         acpi_handle_debug(tz->device->handle, "Temperature is %lu dK\n",
 158                           tz->temperature);
 159
 160         return 0;
 161 }
 162
 163 static int acpi_thermal_get_polling_frequency(struct acpi_thermal *tz)
 164 {
 165         acpi_status status = AE_OK;
 166         unsigned long long tmp;
 167
 168         if (!tz)
 169                 return -EINVAL;
 170
 171         status = acpi_evaluate_integer(tz->device->handle, "_TZP", NULL, &tmp);
 172         if (ACPI_FAILURE(status))
 173                 return -ENODEV;
 174
 175         tz->polling_frequency = tmp;
 176         acpi_handle_debug(tz->device->handle, "Polling frequency is %lu dS\n",
 177                           tz->polling_frequency);
 178
 179         return 0;
 180 }
 181
 182 static int acpi_thermal_temp(struct acpi_thermal *tz, int temp_deci_k)
 183 {
 184         if (temp_deci_k == THERMAL_TEMP_INVALID)
 185                 return THERMAL_TEMP_INVALID;
 186
 187         return deci_kelvin_to_millicelsius_with_offset(temp_deci_k,
 188                                                        tz->kelvin_offset);
 189 }
 190
 191 static void __acpi_thermal_trips_update(struct acpi_thermal *tz, int flag)
 192 {
 193         acpi_status status;
 194         unsigned long long tmp;
 195         struct acpi_handle_list devices;
 196         bool valid = false;
 197         int i;
 198
 199         /* Critical Shutdown */
 200         if (flag & ACPI_TRIPS_CRITICAL) {
 201                 status = acpi_evaluate_integer(tz->device->handle, "_CRT", NULL, &tmp);
 202                 tz->trips.critical.temperature = tmp;
 203                 /*
 204                  * Treat freezing temperatures as invalid as well; some
 205                  * BIOSes return really low values and cause reboots at startup.
 206                  * Below zero (Celsius) values clearly aren't right for sure..
 207                  * ... so lets discard those as invalid.
 208                  */
 209                 if (ACPI_FAILURE(status)) {
 210                         tz->trips.critical.valid = false;
 211                         acpi_handle_debug(tz->device->handle,
 212                                           "No critical threshold\n");
 213                 } else if (tmp <= 2732) {
 214                         pr_info(FW_BUG "Invalid critical threshold (%llu)\n", tmp);
 215                         tz->trips.critical.valid = false;
 216                 } else {
 217                         tz->trips.critical.valid = true;
 218                         acpi_handle_debug(tz->device->handle,
 219                                           "Found critical threshold [%lu]\n",
 220                                           tz->trips.critical.temperature);
 221                 }
 222                 if (tz->trips.critical.valid) {
 223                         if (crt == -1) {
 224                                 tz->trips.critical.valid = false;
 225                         } else if (crt > 0) {
 226                                 unsigned long crt_k = celsius_to_deci_kelvin(crt);
 227
 228                                 /*
 229                                  * Allow override critical threshold
 230                                  */
 231                                 if (crt_k > tz->trips.critical.temperature)
 232                                         pr_info("Critical threshold %d C\n", crt);
 233
 234                                 tz->trips.critical.temperature = crt_k;
 235                         }
 236                 }
 237         }
 238
 239         /* Critical Sleep (optional) */
 240         if (flag & ACPI_TRIPS_HOT) {
 241                 status = acpi_evaluate_integer(tz->device->handle, "_HOT", NULL, &tmp);
 242                 if (ACPI_FAILURE(status)) {
 243                         tz->trips.hot.valid = false;
 244                         acpi_handle_debug(tz->device->handle,
 245                                           "No hot threshold\n");
 246                 } else {
 247                         tz->trips.hot.temperature = tmp;
 248                         tz->trips.hot.valid = true;
 249                         acpi_handle_debug(tz->device->handle,
 250                                           "Found hot threshold [%lu]\n",
 251                                           tz->trips.hot.temperature);
 252                 }
 253         }
 254
 255         /* Passive (optional) */
 256         if (((flag & ACPI_TRIPS_PASSIVE) && tz->trips.passive.trip.valid) ||
 257             flag == ACPI_TRIPS_INIT) {
 258                 valid = tz->trips.passive.trip.valid;
 259                 if (psv == -1) {
 260                         status = AE_SUPPORT;
 261                 } else if (psv > 0) {
 262                         tmp = celsius_to_deci_kelvin(psv);
 263                         status = AE_OK;
 264                 } else {
 265                         status = acpi_evaluate_integer(tz->device->handle,
 266                                                        "_PSV", NULL, &tmp);
 267                 }
 268
 269                 if (ACPI_FAILURE(status)) {
 270                         tz->trips.passive.trip.valid = false;
 271                 } else {
 272                         tz->trips.passive.trip.temperature = tmp;
 273                         tz->trips.passive.trip.valid = true;
 274                         if (flag == ACPI_TRIPS_INIT) {
 275                                 status = acpi_evaluate_integer(tz->device->handle,
 276                                                                "_TC1", NULL, &tmp);
 277                                 if (ACPI_FAILURE(status))
 278                                         tz->trips.passive.trip.valid = false;
 279                                 else
 280                                         tz->trips.passive.tc1 = tmp;
 281
 282                                 status = acpi_evaluate_integer(tz->device->handle,
 283                                                                "_TC2", NULL, &tmp);
 284                                 if (ACPI_FAILURE(status))
 285                                         tz->trips.passive.trip.valid = false;
 286                                 else
 287                                         tz->trips.passive.tc2 = tmp;
 288
 289                                 status = acpi_evaluate_integer(tz->device->handle,
 290                                                                "_TSP", NULL, &tmp);
 291                                 if (ACPI_FAILURE(status))
 292                                         tz->trips.passive.trip.valid = false;
 293                                 else
 294                                         tz->trips.passive.tsp = tmp;
 295                         }
 296                 }
 297         }
 298         if ((flag & ACPI_TRIPS_DEVICES) && tz->trips.passive.trip.valid) {
 299                 memset(&devices, 0, sizeof(struct acpi_handle_list));
 300                 status = acpi_evaluate_reference(tz->device->handle, "_PSL",
 301                                                  NULL, &devices);
 302                 if (ACPI_FAILURE(status)) {
 303                         acpi_handle_info(tz->device->handle,
 304                                          "Invalid passive threshold\n");
 305                         tz->trips.passive.trip.valid = false;
 306                 } else {
 307                         tz->trips.passive.trip.valid = true;
 308                 }
 309
 310                 if (memcmp(&tz->trips.passive.devices, &devices,
 311                            sizeof(struct acpi_handle_list))) {
 312                         memcpy(&tz->trips.passive.devices, &devices,
 313                                sizeof(struct acpi_handle_list));
 314                         ACPI_THERMAL_TRIPS_EXCEPTION(flag, tz, "device");
 315                 }
 316         }
 317         if ((flag & ACPI_TRIPS_PASSIVE) || (flag & ACPI_TRIPS_DEVICES)) {
 318                 if (valid != tz->trips.passive.trip.valid)
 319                         ACPI_THERMAL_TRIPS_EXCEPTION(flag, tz, "state");
 320         }
 321
 322         /* Active (optional) */
 323         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
 324                 char name[5] = { '_', 'A', 'C', ('0' + i), '\0' };
 325                 valid = tz->trips.active[i].trip.valid;
 326
 327                 if (act == -1)
 328                         break; /* disable all active trip points */
 329
 330                 if (flag == ACPI_TRIPS_INIT || ((flag & ACPI_TRIPS_ACTIVE) &&
 331                     tz->trips.active[i].trip.valid)) {
 332                         status = acpi_evaluate_integer(tz->device->handle,
 333                                                        name, NULL, &tmp);
 334                         if (ACPI_FAILURE(status)) {
 335                                 tz->trips.active[i].trip.valid = false;
 336                                 if (i == 0)
 337                                         break;
 338
 339                                 if (act <= 0)
 340                                         break;
 341
 342                                 if (i == 1)
 343                                         tz->trips.active[0].trip.temperature =
 344                                                         celsius_to_deci_kelvin(act);
 345                                 else
 346                                         /*
 347                                          * Don't allow override higher than
 348                                          * the next higher trip point
 349                                          */
 350                                         tz->trips.active[i-1].trip.temperature =
 351                                                 min_t(unsigned long,
 352                                                       tz->trips.active[i-2].trip.temperature,
 353                                                       celsius_to_deci_kelvin(act));
 354
 355                                 break;
 356                         } else {
 357                                 tz->trips.active[i].trip.temperature = tmp;
 358                                 tz->trips.active[i].trip.valid = true;
 359                         }
 360                 }
 361
 362                 name[2] = 'L';
 363                 if ((flag & ACPI_TRIPS_DEVICES) && tz->trips.active[i].trip.valid) {
 364                         memset(&devices, 0, sizeof(struct acpi_handle_list));
 365                         status = acpi_evaluate_reference(tz->device->handle,
 366                                                          name, NULL, &devices);
 367                         if (ACPI_FAILURE(status)) {
 368                                 acpi_handle_info(tz->device->handle,
 369                                                  "Invalid active%d threshold\n", i);
 370                                 tz->trips.active[i].trip.valid = false;
 371                         } else {
 372                                 tz->trips.active[i].trip.valid = true;
 373                         }
 374
 375                         if (memcmp(&tz->trips.active[i].devices, &devices,
 376                                    sizeof(struct acpi_handle_list))) {
 377                                 memcpy(&tz->trips.active[i].devices, &devices,
 378                                        sizeof(struct acpi_handle_list));
 379                                 ACPI_THERMAL_TRIPS_EXCEPTION(flag, tz, "device");
 380                         }
 381                 }
 382                 if ((flag & ACPI_TRIPS_ACTIVE) || (flag & ACPI_TRIPS_DEVICES))
 383                         if (valid != tz->trips.active[i].trip.valid)
 384                                 ACPI_THERMAL_TRIPS_EXCEPTION(flag, tz, "state");
 385
 386                 if (!tz->trips.active[i].trip.valid)
 387                         break;
 388         }
 389
 390         if (flag & ACPI_TRIPS_DEVICES) {
 391                 memset(&devices, 0, sizeof(devices));
 392                 status = acpi_evaluate_reference(tz->device->handle, "_TZD",
 393                                                  NULL, &devices);
 394                 if (ACPI_SUCCESS(status) &&
 395                     memcmp(&tz->devices, &devices, sizeof(devices))) {
 396                         tz->devices = devices;
 397                         ACPI_THERMAL_TRIPS_EXCEPTION(flag, tz, "device");
 398                 }
 399         }
 400 }
 401
 402 static int acpi_thermal_adjust_trip(struct thermal_trip *trip, void *data)
 403 {
 404         struct acpi_thermal_trip *acpi_trip = trip->priv;
 405         struct acpi_thermal *tz = data;
 406
 407         if (!acpi_trip)
 408                 return 0;
 409
 410         if (acpi_trip->valid)
 411                 trip->temperature = acpi_thermal_temp(tz, acpi_trip->temperature);
 412         else
 413                 trip->temperature = THERMAL_TEMP_INVALID;
 414
 415         return 0;
 416 }
 417
 418 static void acpi_thermal_adjust_thermal_zone(struct thermal_zone_device *thermal,
 419                                              unsigned long data)
 420 {
 421         struct acpi_thermal *tz = thermal_zone_device_priv(thermal);
 422         int flag = data == ACPI_THERMAL_NOTIFY_THRESHOLDS ?
 423                                 ACPI_TRIPS_THRESHOLDS : ACPI_TRIPS_DEVICES;
 424
 425         __acpi_thermal_trips_update(tz, flag);
 426
 427         for_each_thermal_trip(tz->thermal_zone, acpi_thermal_adjust_trip, tz);
 428 }
 429
 430 static void acpi_queue_thermal_check(struct acpi_thermal *tz)
 431 {
 432         if (!work_pending(&tz->thermal_check_work))
 433                 queue_work(acpi_thermal_pm_queue, &tz->thermal_check_work);
 434 }
 435
 436 static void acpi_thermal_trips_update(struct acpi_thermal *tz, u32 event)
 437 {
 438         struct acpi_device *adev = tz->device;
 439
 440         /*
 441          * Use thermal_zone_device_exec() to carry out the trip points
 442          * update, so as to protect thermal_get_trend() from getting stale
 443          * trip point temperatures and to prevent thermal_zone_device_update()
 444          * invoked from acpi_thermal_check_fn() from producing inconsistent
 445          * results.
 446          */
 447         thermal_zone_device_exec(tz->thermal_zone,
 448                                  acpi_thermal_adjust_thermal_zone, event);
 449         acpi_queue_thermal_check(tz);
 450         acpi_bus_generate_netlink_event(adev->pnp.device_class,
 451                                         dev_name(&adev->dev), event, 0);
 452 }
 453
 454 static int acpi_thermal_get_trip_points(struct acpi_thermal *tz)
 455 {
 456         bool valid;
 457         int i;
 458
 459         __acpi_thermal_trips_update(tz, ACPI_TRIPS_INIT);
 460
 461         valid = tz->trips.critical.valid |
 462                 tz->trips.hot.valid |
 463                 tz->trips.passive.trip.valid;
 464
 465         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++)
 466                 valid = valid || tz->trips.active[i].trip.valid;
 467
 468         if (!valid) {
 469                 pr_warn(FW_BUG "No valid trip found\n");
 470                 return -ENODEV;
 471         }
 472         return 0;
 473 }
 474
 475 /* sys I/F for generic thermal sysfs support */
 476
 477 static int thermal_get_temp(struct thermal_zone_device *thermal, int *temp)
 478 {
 479         struct acpi_thermal *tz = thermal_zone_device_priv(thermal);
 480         int result;
 481
 482         if (!tz)
 483                 return -EINVAL;
 484
 485         result = acpi_thermal_get_temperature(tz);
 486         if (result)
 487                 return result;
 488
 489         *temp = deci_kelvin_to_millicelsius_with_offset(tz->temperature,
 490                                                         tz->kelvin_offset);
 491         return 0;
 492 }
 493
 494 static int thermal_get_trend(struct thermal_zone_device *thermal,
 495                              struct thermal_trip *trip,
 496                              enum thermal_trend *trend)
 497 {
 498         struct acpi_thermal *tz = thermal_zone_device_priv(thermal);
 499         struct acpi_thermal_trip *acpi_trip;
 500         int t;
 501
 502         if (!tz || !trip)
 503                 return -EINVAL;
 504
 505         acpi_trip = trip->priv;
 506         if (!acpi_trip || !acpi_trip->valid)
 507                 return -EINVAL;
 508
 509         switch (trip->type) {
 510         case THERMAL_TRIP_PASSIVE:
 511                 t = tz->trips.passive.tc1 * (tz->temperature -
 512                                                 tz->last_temperature) +
 513                         tz->trips.passive.tc2 * (tz->temperature -
 514                                                 acpi_trip->temperature);
 515                 if (t > 0)
 516                         *trend = THERMAL_TREND_RAISING;
 517                 else if (t < 0)
 518                         *trend = THERMAL_TREND_DROPPING;
 519                 else
 520                         *trend = THERMAL_TREND_STABLE;
 521
 522                 return 0;
 523
 524         case THERMAL_TRIP_ACTIVE:
 525                 t = acpi_thermal_temp(tz, tz->temperature);
 526                 if (t <= trip->temperature)
 527                         break;
 528
 529                 *trend = THERMAL_TREND_RAISING;
 530
 531                 return 0;
 532
 533         default:
 534                 break;
 535         }
 536
 537         return -EINVAL;
 538 }
 539
 540 static void acpi_thermal_zone_device_hot(struct thermal_zone_device *thermal)
 541 {
 542         struct acpi_thermal *tz = thermal_zone_device_priv(thermal);
 543
 544         acpi_bus_generate_netlink_event(tz->device->pnp.device_class,
 545                                         dev_name(&tz->device->dev),
 546                                         ACPI_THERMAL_NOTIFY_HOT, 1);
 547 }
 548
 549 static void acpi_thermal_zone_device_critical(struct thermal_zone_device *thermal)
 550 {
 551         struct acpi_thermal *tz = thermal_zone_device_priv(thermal);
 552
 553         acpi_bus_generate_netlink_event(tz->device->pnp.device_class,
 554                                         dev_name(&tz->device->dev),
 555                                         ACPI_THERMAL_NOTIFY_CRITICAL, 1);
 556
 557         thermal_zone_device_critical(thermal);
 558 }
 559
 560 static int acpi_thermal_cooling_device_cb(struct thermal_zone_device *thermal,
 561                                           struct thermal_cooling_device *cdev,
 562                                           bool bind)
 563 {
 564         struct acpi_device *device = cdev->devdata;
 565         struct acpi_thermal *tz = thermal_zone_device_priv(thermal);
 566         struct acpi_device *dev;
 567         acpi_handle handle;
 568         int i;
 569         int j;
 570         int trip = -1;
 571         int result = 0;
 572
 573         if (tz->trips.critical.valid)
 574                 trip++;
 575
 576         if (tz->trips.hot.valid)
 577                 trip++;
 578
 579         if (tz->trips.passive.trip.valid) {
 580                 trip++;
 581                 for (i = 0; i < tz->trips.passive.devices.count; i++) {
 582                         handle = tz->trips.passive.devices.handles[i];
 583                         dev = acpi_fetch_acpi_dev(handle);
 584                         if (dev != device)
 585                                 continue;
 586
 587                         if (bind)
 588                                 result = thermal_zone_bind_cooling_device(
 589                                                 thermal, trip, cdev,
 590                                                 THERMAL_NO_LIMIT,
 591                                                 THERMAL_NO_LIMIT,
 592                                                 THERMAL_WEIGHT_DEFAULT);
 593                         else
 594                                 result =
 595                                         thermal_zone_unbind_cooling_device(
 596                                                 thermal, trip, cdev);
 597
 598                         if (result)
 599                                 goto failed;
 600                 }
 601         }
 602
 603         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
 604                 if (!tz->trips.active[i].trip.valid)
 605                         break;
 606
 607                 trip++;
 608                 for (j = 0; j < tz->trips.active[i].devices.count; j++) {
 609                         handle = tz->trips.active[i].devices.handles[j];
 610                         dev = acpi_fetch_acpi_dev(handle);
 611                         if (dev != device)
 612                                 continue;
 613
 614                         if (bind)
 615                                 result = thermal_zone_bind_cooling_device(
 616                                                 thermal, trip, cdev,
 617                                                 THERMAL_NO_LIMIT,
 618                                                 THERMAL_NO_LIMIT,
 619                                                 THERMAL_WEIGHT_DEFAULT);
 620                         else
 621                                 result = thermal_zone_unbind_cooling_device(
 622                                                 thermal, trip, cdev);
 623
 624                         if (result)
 625                                 goto failed;
 626                 }
 627         }
 628
 629 failed:
 630         return result;
 631 }
 632
 633 static int
 634 acpi_thermal_bind_cooling_device(struct thermal_zone_device *thermal,
 635                                  struct thermal_cooling_device *cdev)
 636 {
 637         return acpi_thermal_cooling_device_cb(thermal, cdev, true);
 638 }
 639
 640 static int
 641 acpi_thermal_unbind_cooling_device(struct thermal_zone_device *thermal,
 642                                    struct thermal_cooling_device *cdev)
 643 {
 644         return acpi_thermal_cooling_device_cb(thermal, cdev, false);
 645 }
 646
 647 static struct thermal_zone_device_ops acpi_thermal_zone_ops = {
 648         .bind = acpi_thermal_bind_cooling_device,
 649         .unbind = acpi_thermal_unbind_cooling_device,
 650         .get_temp = thermal_get_temp,
 651         .get_trend = thermal_get_trend,
 652         .hot = acpi_thermal_zone_device_hot,
 653         .critical = acpi_thermal_zone_device_critical,
 654 };
 655
 656 static int acpi_thermal_zone_sysfs_add(struct acpi_thermal *tz)
 657 {
 658         struct device *tzdev = thermal_zone_device(tz->thermal_zone);
 659         int ret;
 660
 661         ret = sysfs_create_link(&tz->device->dev.kobj,
 662                                 &tzdev->kobj, "thermal_zone");
 663         if (ret)
 664                 return ret;
 665
 666         ret = sysfs_create_link(&tzdev->kobj,
 667                                    &tz->device->dev.kobj, "device");
 668         if (ret)
 669                 sysfs_remove_link(&tz->device->dev.kobj, "thermal_zone");
 670
 671         return ret;
 672 }
 673
 674 static void acpi_thermal_zone_sysfs_remove(struct acpi_thermal *tz)
 675 {
 676         struct device *tzdev = thermal_zone_device(tz->thermal_zone);
 677
 678         sysfs_remove_link(&tz->device->dev.kobj, "thermal_zone");
 679         sysfs_remove_link(&tzdev->kobj, "device");
 680 }
 681
 682 static int acpi_thermal_register_thermal_zone(struct acpi_thermal *tz)
 683 {
 684         struct acpi_thermal_trip *acpi_trip;
 685         struct thermal_trip *trip;
 686         int passive_delay = 0;
 687         int trip_count = 0;
 688         int result;
 689         int i;
 690
 691         if (tz->trips.critical.valid)
 692                 trip_count++;
 693
 694         if (tz->trips.hot.valid)
 695                 trip_count++;
 696
 697         if (tz->trips.passive.trip.valid) {
 698                 trip_count++;
 699                 passive_delay = tz->trips.passive.tsp * 100;
 700         }
 701
 702         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE && tz->trips.active[i].trip.valid; i++)
 703                 trip_count++;
 704
 705         trip = kcalloc(trip_count, sizeof(*trip), GFP_KERNEL);
 706         if (!trip)
 707                 return -ENOMEM;
 708
 709         tz->trip_table = trip;
 710
 711         if (tz->trips.critical.valid) {
 712                 trip->type = THERMAL_TRIP_CRITICAL;
 713                 trip->temperature = acpi_thermal_temp(tz, tz->trips.critical.temperature);
 714                 trip++;
 715         }
 716
 717         if (tz->trips.hot.valid) {
 718                 trip->type = THERMAL_TRIP_HOT;
 719                 trip->temperature = acpi_thermal_temp(tz, tz->trips.hot.temperature);
 720                 trip++;
 721         }
 722
 723         acpi_trip = &tz->trips.passive.trip;
 724         if (acpi_trip->valid) {
 725                 trip->type = THERMAL_TRIP_PASSIVE;
 726                 trip->temperature = acpi_thermal_temp(tz, acpi_trip->temperature);
 727                 trip->priv = acpi_trip;
 728                 trip++;
 729         }
 730
 731         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
 732                 acpi_trip = &tz->trips.active[i].trip;
 733
 734                 if (!acpi_trip->valid)
 735                         break;
 736
 737                 trip->type = THERMAL_TRIP_ACTIVE;
 738                 trip->temperature = acpi_thermal_temp(tz, acpi_trip->temperature);
 739                 trip->priv = acpi_trip;
 740                 trip++;
 741         }
 742
 743         tz->thermal_zone = thermal_zone_device_register_with_trips("acpitz",
 744                                                                    tz->trip_table,
 745                                                                    trip_count,
 746                                                                    0, tz,
 747                                                                    &acpi_thermal_zone_ops,
 748                                                                    NULL,
 749                                                                    passive_delay,
 750                                                                    tz->polling_frequency * 100);
 751         if (IS_ERR(tz->thermal_zone)) {
 752                 result = PTR_ERR(tz->thermal_zone);
 753                 goto free_trip_table;
 754         }
 755
 756         result = acpi_thermal_zone_sysfs_add(tz);
 757         if (result)
 758                 goto unregister_tzd;
 759
 760         result = thermal_zone_device_enable(tz->thermal_zone);
 761         if (result)
 762                 goto remove_links;
 763
 764         dev_info(&tz->device->dev, "registered as thermal_zone%d\n",
 765                  thermal_zone_device_id(tz->thermal_zone));
 766
 767         return 0;
 768
 769 remove_links:
 770         acpi_thermal_zone_sysfs_remove(tz);
 771 unregister_tzd:
 772         thermal_zone_device_unregister(tz->thermal_zone);
 773 free_trip_table:
 774         kfree(tz->trip_table);
 775
 776         return result;
 777 }
 778
 779 static void acpi_thermal_unregister_thermal_zone(struct acpi_thermal *tz)
 780 {
 781         acpi_thermal_zone_sysfs_remove(tz);
 782         thermal_zone_device_unregister(tz->thermal_zone);
 783         kfree(tz->trip_table);
 784         tz->thermal_zone = NULL;
 785 }
 786
 787
 788 /* --------------------------------------------------------------------------
 789                                  Driver Interface
 790    -------------------------------------------------------------------------- */
 791
 792 static void acpi_thermal_notify(acpi_handle handle, u32 event, void *data)
 793 {
 794         struct acpi_device *device = data;
 795         struct acpi_thermal *tz = acpi_driver_data(device);
 796
 797         if (!tz)
 798                 return;
 799
 800         switch (event) {
 801         case ACPI_THERMAL_NOTIFY_TEMPERATURE:
 802                 acpi_queue_thermal_check(tz);
 803                 break;
 804         case ACPI_THERMAL_NOTIFY_THRESHOLDS:
 805         case ACPI_THERMAL_NOTIFY_DEVICES:
 806                 acpi_thermal_trips_update(tz, event);
 807                 break;
 808         default:
 809                 acpi_handle_debug(device->handle, "Unsupported event [0x%x]\n",
 810                                   event);
 811                 break;
 812         }
 813 }
 814
 815 /*
 816  * On some platforms, the AML code has dependency about
 817  * the evaluating order of _TMP and _CRT/_HOT/_PSV/_ACx.
 818  * 1. On HP Pavilion G4-1016tx, _TMP must be invoked after
 819  *    /_CRT/_HOT/_PSV/_ACx, or else system will be power off.
 820  * 2. On HP Compaq 6715b/6715s, the return value of _PSV is 0
 821  *    if _TMP has never been evaluated.
 822  *
 823  * As this dependency is totally transparent to OS, evaluate
 824  * all of them once, in the order of _CRT/_HOT/_PSV/_ACx,
 825  * _TMP, before they are actually used.
 826  */
 827 static void acpi_thermal_aml_dependency_fix(struct acpi_thermal *tz)
 828 {
 829         acpi_handle handle = tz->device->handle;
 830         unsigned long long value;
 831         int i;
 832
 833         acpi_evaluate_integer(handle, "_CRT", NULL, &value);
 834         acpi_evaluate_integer(handle, "_HOT", NULL, &value);
 835         acpi_evaluate_integer(handle, "_PSV", NULL, &value);
 836         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
 837                 char name[5] = { '_', 'A', 'C', ('0' + i), '\0' };
 838                 acpi_status status;
 839
 840                 status = acpi_evaluate_integer(handle, name, NULL, &value);
 841                 if (status == AE_NOT_FOUND)
 842                         break;
 843         }
 844         acpi_evaluate_integer(handle, "_TMP", NULL, &value);
 845 }
 846
 847 static int acpi_thermal_get_info(struct acpi_thermal *tz)
 848 {
 849         int result;
 850
 851         if (!tz)
 852                 return -EINVAL;
 853
 854         acpi_thermal_aml_dependency_fix(tz);
 855
 856         /* Get trip points [_CRT, _PSV, etc.] (required) */
 857         result = acpi_thermal_get_trip_points(tz);
 858         if (result)
 859                 return result;
 860
 861         /* Get temperature [_TMP] (required) */
 862         result = acpi_thermal_get_temperature(tz);
 863         if (result)
 864                 return result;
 865
 866         /* Set the cooling mode [_SCP] to active cooling (default) */
 867         acpi_execute_simple_method(tz->device->handle, "_SCP",
 868                                    ACPI_THERMAL_MODE_ACTIVE);
 869
 870         /* Get default polling frequency [_TZP] (optional) */
 871         if (tzp)
 872                 tz->polling_frequency = tzp;
 873         else
 874                 acpi_thermal_get_polling_frequency(tz);
 875
 876         return 0;
 877 }
 878
 879 /*
 880  * The exact offset between Kelvin and degree Celsius is 273.15. However ACPI
 881  * handles temperature values with a single decimal place. As a consequence,
 882  * some implementations use an offset of 273.1 and others use an offset of
 883  * 273.2. Try to find out which one is being used, to present the most
 884  * accurate and visually appealing number.
 885  *
 886  * The heuristic below should work for all ACPI thermal zones which have a
 887  * critical trip point with a value being a multiple of 0.5 degree Celsius.
 888  */
 889 static void acpi_thermal_guess_offset(struct acpi_thermal *tz)
 890 {
 891         if (tz->trips.critical.valid &&
 892             (tz->trips.critical.temperature % 5) == 1)
 893                 tz->kelvin_offset = 273100;
 894         else
 895                 tz->kelvin_offset = 273200;
 896 }
 897
 898 static void acpi_thermal_check_fn(struct work_struct *work)
 899 {
 900         struct acpi_thermal *tz = container_of(work, struct acpi_thermal,
 901                                                thermal_check_work);
 902
 903         /*
 904          * In general, it is not sufficient to check the pending bit, because
 905          * subsequent instances of this function may be queued after one of them
 906          * has started running (e.g. if _TMP sleeps).  Avoid bailing out if just
 907          * one of them is running, though, because it may have done the actual
 908          * check some time ago, so allow at least one of them to block on the
 909          * mutex while another one is running the update.
 910          */
 911         if (!refcount_dec_not_one(&tz->thermal_check_count))
 912                 return;
 913
 914         mutex_lock(&tz->thermal_check_lock);
 915
 916         thermal_zone_device_update(tz->thermal_zone, THERMAL_EVENT_UNSPECIFIED);
 917
 918         refcount_inc(&tz->thermal_check_count);
 919
 920         mutex_unlock(&tz->thermal_check_lock);
 921 }
 922
 923 static int acpi_thermal_add(struct acpi_device *device)
 924 {
 925         struct acpi_thermal *tz;
 926         int result;
 927
 928         if (!device)
 929                 return -EINVAL;
 930
 931         tz = kzalloc(sizeof(struct acpi_thermal), GFP_KERNEL);
 932         if (!tz)
 933                 return -ENOMEM;
 934
 935         tz->device = device;
 936         strcpy(tz->name, device->pnp.bus_id);
 937         strcpy(acpi_device_name(device), ACPI_THERMAL_DEVICE_NAME);
 938         strcpy(acpi_device_class(device), ACPI_THERMAL_CLASS);
 939         device->driver_data = tz;
 940
 941         result = acpi_thermal_get_info(tz);
 942         if (result)
 943                 goto free_memory;
 944
 945         acpi_thermal_guess_offset(tz);
 946
 947         result = acpi_thermal_register_thermal_zone(tz);
 948         if (result)
 949                 goto free_memory;
 950
 951         refcount_set(&tz->thermal_check_count, 3);
 952         mutex_init(&tz->thermal_check_lock);
 953         INIT_WORK(&tz->thermal_check_work, acpi_thermal_check_fn);
 954
 955         pr_info("%s [%s] (%ld C)\n", acpi_device_name(device),
 956                 acpi_device_bid(device), deci_kelvin_to_celsius(tz->temperature));
 957
 958         result = acpi_dev_install_notify_handler(device, ACPI_DEVICE_NOTIFY,
 959                                                  acpi_thermal_notify);
 960         if (result)
 961                 goto flush_wq;
 962
 963         return 0;
 964
 965 flush_wq:
 966         flush_workqueue(acpi_thermal_pm_queue);
 967         acpi_thermal_unregister_thermal_zone(tz);
 968 free_memory:
 969         kfree(tz);
 970
 971         return result;
 972 }
 973
 974 static void acpi_thermal_remove(struct acpi_device *device)
 975 {
 976         struct acpi_thermal *tz;
 977
 978         if (!device || !acpi_driver_data(device))
 979                 return;
 980
 981         tz = acpi_driver_data(device);
 982
 983         acpi_dev_remove_notify_handler(device, ACPI_DEVICE_NOTIFY,
 984                                        acpi_thermal_notify);
 985
 986         flush_workqueue(acpi_thermal_pm_queue);
 987         acpi_thermal_unregister_thermal_zone(tz);
 988
 989         kfree(tz);
 990 }
 991
 992 #ifdef CONFIG_PM_SLEEP
 993 static int acpi_thermal_suspend(struct device *dev)
 994 {
 995         /* Make sure the previously queued thermal check work has been done */
 996         flush_workqueue(acpi_thermal_pm_queue);
 997         return 0;
 998 }
 999
1000 static int acpi_thermal_resume(struct device *dev)
1001 {
1002         struct acpi_thermal *tz;
1003         int i, j, power_state;
1004
1005         if (!dev)
1006                 return -EINVAL;
1007
1008         tz = acpi_driver_data(to_acpi_device(dev));
1009         if (!tz)
1010                 return -EINVAL;
1011
1012         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
1013                 if (!tz->trips.active[i].trip.valid)
1014                         break;
1015
1016                 for (j = 0; j < tz->trips.active[i].devices.count; j++) {
1017                         acpi_bus_update_power(tz->trips.active[i].devices.handles[j],
1018                                               &power_state);
1019                 }
1020         }
1021
1022         acpi_queue_thermal_check(tz);
1023
1024         return AE_OK;
1025 }
1026 #else
1027 #define acpi_thermal_suspend    NULL
1028 #define acpi_thermal_resume     NULL
1029 #endif
1030 static SIMPLE_DEV_PM_OPS(acpi_thermal_pm, acpi_thermal_suspend, acpi_thermal_resume);
1031
1032 static const struct acpi_device_id  thermal_device_ids[] = {
1033         {ACPI_THERMAL_HID, 0},
1034         {"", 0},
1035 };
1036 MODULE_DEVICE_TABLE(acpi, thermal_device_ids);
1037
1038 static struct acpi_driver acpi_thermal_driver = {
1039         .name = "thermal",
1040         .class = ACPI_THERMAL_CLASS,
1041         .ids = thermal_device_ids,
1042         .ops = {
1043                 .add = acpi_thermal_add,
1044                 .remove = acpi_thermal_remove,
1045                 },
1046         .drv.pm = &acpi_thermal_pm,
1047 };
1048
1049 static int thermal_act(const struct dmi_system_id *d) {
1050         if (act == 0) {
1051                 pr_notice("%s detected: disabling all active thermal trip points\n",
1052                           d->ident);
1053                 act = -1;
1054         }
1055         return 0;
1056 }
1057 static int thermal_nocrt(const struct dmi_system_id *d) {
1058         pr_notice("%s detected: disabling all critical thermal trip point actions.\n",
1059                   d->ident);
1060         crt = -1;
1061         return 0;
1062 }
1063 static int thermal_tzp(const struct dmi_system_id *d) {
1064         if (tzp == 0) {
1065                 pr_notice("%s detected: enabling thermal zone polling\n",
1066                           d->ident);
1067                 tzp = 300;      /* 300 dS = 30 Seconds */
1068         }
1069         return 0;
1070 }
1071 static int thermal_psv(const struct dmi_system_id *d) {
1072         if (psv == 0) {
1073                 pr_notice("%s detected: disabling all passive thermal trip points\n",
1074                           d->ident);
1075                 psv = -1;
1076         }
1077         return 0;
1078 }
1079
1080 static const struct dmi_system_id thermal_dmi_table[] __initconst = {
1081         /*
1082          * Award BIOS on this AOpen makes thermal control almost worthless.
1083          * http://bugzilla.kernel.org/show_bug.cgi?id=8842
1084          */
1085         {
1086          .callback = thermal_act,
1087          .ident = "AOpen i915GMm-HFS",
1088          .matches = {
1089                 DMI_MATCH(DMI_BOARD_VENDOR, "AOpen"),
1090                 DMI_MATCH(DMI_BOARD_NAME, "i915GMm-HFS"),
1091                 },
1092         },
1093         {
1094          .callback = thermal_psv,
1095          .ident = "AOpen i915GMm-HFS",
1096          .matches = {
1097                 DMI_MATCH(DMI_BOARD_VENDOR, "AOpen"),
1098                 DMI_MATCH(DMI_BOARD_NAME, "i915GMm-HFS"),
1099                 },
1100         },
1101         {
1102          .callback = thermal_tzp,
1103          .ident = "AOpen i915GMm-HFS",
1104          .matches = {
1105                 DMI_MATCH(DMI_BOARD_VENDOR, "AOpen"),
1106                 DMI_MATCH(DMI_BOARD_NAME, "i915GMm-HFS"),
1107                 },
1108         },
1109         {
1110          .callback = thermal_nocrt,
1111          .ident = "Gigabyte GA-7ZX",
1112          .matches = {
1113                 DMI_MATCH(DMI_BOARD_VENDOR, "Gigabyte Technology Co., Ltd."),
1114                 DMI_MATCH(DMI_BOARD_NAME, "7ZX"),
1115                 },
1116         },
1117         {}
1118 };
1119
1120 static int __init acpi_thermal_init(void)
1121 {
1122         int result;
1123
1124         dmi_check_system(thermal_dmi_table);
1125
1126         if (off) {
1127                 pr_notice("thermal control disabled\n");
1128                 return -ENODEV;
1129         }
1130
1131         acpi_thermal_pm_queue = alloc_workqueue("acpi_thermal_pm",
1132                                                 WQ_HIGHPRI | WQ_MEM_RECLAIM, 0);
1133         if (!acpi_thermal_pm_queue)
1134                 return -ENODEV;
1135
1136         result = acpi_bus_register_driver(&acpi_thermal_driver);
1137         if (result < 0) {
1138                 destroy_workqueue(acpi_thermal_pm_queue);
1139                 return -ENODEV;
1140         }
1141
1142         return 0;
1143 }
1144
1145 static void __exit acpi_thermal_exit(void)
1146 {
1147         acpi_bus_unregister_driver(&acpi_thermal_driver);
1148         destroy_workqueue(acpi_thermal_pm_queue);
1149 }
1150
1151 module_init(acpi_thermal_init);
1152 module_exit(acpi_thermal_exit);
1153
1154 MODULE_AUTHOR("Paul Diefenbaugh");
1155 MODULE_DESCRIPTION("ACPI Thermal Zone Driver");
1156 MODULE_LICENSE("GPL");