drivers/acpi/thermal.c

   1 /*
   2  *  acpi_thermal.c - ACPI Thermal Zone Driver ($Revision: 41 $)
   3  *
   4  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   6  *
   7  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License as published by
  11  *  the Free Software Foundation; either version 2 of the License, or (at
  12  *  your option) any later version.
  13  *
  14  *  This program is distributed in the hope that it will be useful, but
  15  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  *  General Public License for more details.
  18  *
  19  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  20  *
  21  *  This driver fully implements the ACPI thermal policy as described in the
  22  *  ACPI 2.0 Specification.
  23  *
  24  *  TBD: 1. Implement passive cooling hysteresis.
  25  *       2. Enhance passive cooling (CPU) states/limit interface to support
  26  *          concepts of 'multiple limiters', upper/lower limits, etc.
  27  *
  28  */
  29
  30 #include <linux/kernel.h>
  31 #include <linux/module.h>
  32 #include <linux/dmi.h>
  33 #include <linux/init.h>
  34 #include <linux/slab.h>
  35 #include <linux/types.h>
  36 #include <linux/jiffies.h>
  37 #include <linux/kmod.h>
  38 #include <linux/reboot.h>
  39 #include <linux/device.h>
  40 #include <linux/thermal.h>
  41 #include <linux/acpi.h>
  42 #include <linux/workqueue.h>
  43 #include <asm/uaccess.h>
  44
  45 #define PREFIX "ACPI: "
  46
  47 #define ACPI_THERMAL_CLASS              "thermal_zone"
  48 #define ACPI_THERMAL_DEVICE_NAME        "Thermal Zone"
  49 #define ACPI_THERMAL_NOTIFY_TEMPERATURE 0x80
  50 #define ACPI_THERMAL_NOTIFY_THRESHOLDS  0x81
  51 #define ACPI_THERMAL_NOTIFY_DEVICES     0x82
  52 #define ACPI_THERMAL_NOTIFY_CRITICAL    0xF0
  53 #define ACPI_THERMAL_NOTIFY_HOT         0xF1
  54 #define ACPI_THERMAL_MODE_ACTIVE        0x00
  55
  56 #define ACPI_THERMAL_MAX_ACTIVE 10
  57 #define ACPI_THERMAL_MAX_LIMIT_STR_LEN 65
  58
  59 #define _COMPONENT              ACPI_THERMAL_COMPONENT
  60 ACPI_MODULE_NAME("thermal");
  61
  62 MODULE_AUTHOR("Paul Diefenbaugh");
  63 MODULE_DESCRIPTION("ACPI Thermal Zone Driver");
  64 MODULE_LICENSE("GPL");
  65
  66 static int act;
  67 module_param(act, int, 0644);
  68 MODULE_PARM_DESC(act, "Disable or override all lowest active trip points.");
  69
  70 static int crt;
  71 module_param(crt, int, 0644);
  72 MODULE_PARM_DESC(crt, "Disable or lower all critical trip points.");
  73
  74 static int tzp;
  75 module_param(tzp, int, 0444);
  76 MODULE_PARM_DESC(tzp, "Thermal zone polling frequency, in 1/10 seconds.");
  77
  78 static int nocrt;
  79 module_param(nocrt, int, 0);
  80 MODULE_PARM_DESC(nocrt, "Set to take no action upon ACPI thermal zone critical trips points.");
  81
  82 static int off;
  83 module_param(off, int, 0);
  84 MODULE_PARM_DESC(off, "Set to disable ACPI thermal support.");
  85
  86 static int psv;
  87 module_param(psv, int, 0644);
  88 MODULE_PARM_DESC(psv, "Disable or override all passive trip points.");
  89
  90 static struct workqueue_struct *acpi_thermal_pm_queue;
  91
  92 static int acpi_thermal_add(struct acpi_device *device);
  93 static int acpi_thermal_remove(struct acpi_device *device);
  94 static void acpi_thermal_notify(struct acpi_device *device, u32 event);
  95
  96 static const struct acpi_device_id  thermal_device_ids[] = {
  97         {ACPI_THERMAL_HID, 0},
  98         {"", 0},
  99 };
 100 MODULE_DEVICE_TABLE(acpi, thermal_device_ids);
 101
 102 #ifdef CONFIG_PM_SLEEP
 103 static int acpi_thermal_suspend(struct device *dev);
 104 static int acpi_thermal_resume(struct device *dev);
 105 #else
 106 #define acpi_thermal_suspend NULL
 107 #define acpi_thermal_resume NULL
 108 #endif
 109 static SIMPLE_DEV_PM_OPS(acpi_thermal_pm, acpi_thermal_suspend, acpi_thermal_resume);
 110
 111 static struct acpi_driver acpi_thermal_driver = {
 112         .name = "thermal",
 113         .class = ACPI_THERMAL_CLASS,
 114         .ids = thermal_device_ids,
 115         .ops = {
 116                 .add = acpi_thermal_add,
 117                 .remove = acpi_thermal_remove,
 118                 .notify = acpi_thermal_notify,
 119                 },
 120         .drv.pm = &acpi_thermal_pm,
 121 };
 122
 123 struct acpi_thermal_state {
 124         u8 critical:1;
 125         u8 hot:1;
 126         u8 passive:1;
 127         u8 active:1;
 128         u8 reserved:4;
 129         int active_index;
 130 };
 131
 132 struct acpi_thermal_state_flags {
 133         u8 valid:1;
 134         u8 enabled:1;
 135         u8 reserved:6;
 136 };
 137
 138 struct acpi_thermal_critical {
 139         struct acpi_thermal_state_flags flags;
 140         unsigned long temperature;
 141 };
 142
 143 struct acpi_thermal_hot {
 144         struct acpi_thermal_state_flags flags;
 145         unsigned long temperature;
 146 };
 147
 148 struct acpi_thermal_passive {
 149         struct acpi_thermal_state_flags flags;
 150         unsigned long temperature;
 151         unsigned long tc1;
 152         unsigned long tc2;
 153         unsigned long tsp;
 154         struct acpi_handle_list devices;
 155 };
 156
 157 struct acpi_thermal_active {
 158         struct acpi_thermal_state_flags flags;
 159         unsigned long temperature;
 160         struct acpi_handle_list devices;
 161 };
 162
 163 struct acpi_thermal_trips {
 164         struct acpi_thermal_critical critical;
 165         struct acpi_thermal_hot hot;
 166         struct acpi_thermal_passive passive;
 167         struct acpi_thermal_active active[ACPI_THERMAL_MAX_ACTIVE];
 168 };
 169
 170 struct acpi_thermal_flags {
 171         u8 cooling_mode:1;      /* _SCP */
 172         u8 devices:1;           /* _TZD */
 173         u8 reserved:6;
 174 };
 175
 176 struct acpi_thermal {
 177         struct acpi_device * device;
 178         acpi_bus_id name;
 179         unsigned long temperature;
 180         unsigned long last_temperature;
 181         unsigned long polling_frequency;
 182         volatile u8 zombie;
 183         struct acpi_thermal_flags flags;
 184         struct acpi_thermal_state state;
 185         struct acpi_thermal_trips trips;
 186         struct acpi_handle_list devices;
 187         struct thermal_zone_device *thermal_zone;
 188         int tz_enabled;
 189         int kelvin_offset;
 190         struct work_struct thermal_check_work;
 191 };
 192
 193 /* --------------------------------------------------------------------------
 194                              Thermal Zone Management
 195    -------------------------------------------------------------------------- */
 196
 197 static int acpi_thermal_get_temperature(struct acpi_thermal *tz)
 198 {
 199         acpi_status status = AE_OK;
 200         unsigned long long tmp;
 201
 202         if (!tz)
 203                 return -EINVAL;
 204
 205         tz->last_temperature = tz->temperature;
 206
 207         status = acpi_evaluate_integer(tz->device->handle, "_TMP", NULL, &tmp);
 208         if (ACPI_FAILURE(status))
 209                 return -ENODEV;
 210
 211         tz->temperature = tmp;
 212         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Temperature is %lu dK\n",
 213                           tz->temperature));
 214
 215         return 0;
 216 }
 217
 218 static int acpi_thermal_get_polling_frequency(struct acpi_thermal *tz)
 219 {
 220         acpi_status status = AE_OK;
 221         unsigned long long tmp;
 222
 223         if (!tz)
 224                 return -EINVAL;
 225
 226         status = acpi_evaluate_integer(tz->device->handle, "_TZP", NULL, &tmp);
 227         if (ACPI_FAILURE(status))
 228                 return -ENODEV;
 229
 230         tz->polling_frequency = tmp;
 231         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Polling frequency is %lu dS\n",
 232                           tz->polling_frequency));
 233
 234         return 0;
 235 }
 236
 237 static int acpi_thermal_set_cooling_mode(struct acpi_thermal *tz, int mode)
 238 {
 239         if (!tz)
 240                 return -EINVAL;
 241
 242         if (!acpi_has_method(tz->device->handle, "_SCP")) {
 243                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "_SCP not present\n"));
 244                 return -ENODEV;
 245         } else if (ACPI_FAILURE(acpi_execute_simple_method(tz->device->handle,
 246                                                            "_SCP", mode))) {
 247                 return -ENODEV;
 248         }
 249
 250         return 0;
 251 }
 252
 253 #define ACPI_TRIPS_CRITICAL     0x01
 254 #define ACPI_TRIPS_HOT          0x02
 255 #define ACPI_TRIPS_PASSIVE      0x04
 256 #define ACPI_TRIPS_ACTIVE       0x08
 257 #define ACPI_TRIPS_DEVICES      0x10
 258
 259 #define ACPI_TRIPS_REFRESH_THRESHOLDS   (ACPI_TRIPS_PASSIVE | ACPI_TRIPS_ACTIVE)
 260 #define ACPI_TRIPS_REFRESH_DEVICES      ACPI_TRIPS_DEVICES
 261
 262 #define ACPI_TRIPS_INIT      (ACPI_TRIPS_CRITICAL | ACPI_TRIPS_HOT |    \
 263                               ACPI_TRIPS_PASSIVE | ACPI_TRIPS_ACTIVE |  \
 264                               ACPI_TRIPS_DEVICES)
 265
 266 /*
 267  * This exception is thrown out in two cases:
 268  * 1.An invalid trip point becomes invalid or a valid trip point becomes invalid
 269  *   when re-evaluating the AML code.
 270  * 2.TODO: Devices listed in _PSL, _ALx, _TZD may change.
 271  *   We need to re-bind the cooling devices of a thermal zone when this occurs.
 272  */
 273 #define ACPI_THERMAL_TRIPS_EXCEPTION(flags, str)        \
 274 do {    \
 275         if (flags != ACPI_TRIPS_INIT)   \
 276                 ACPI_EXCEPTION((AE_INFO, AE_ERROR,      \
 277                 "ACPI thermal trip point %s changed\n"  \
 278                 "Please send acpidump to linux-acpi@vger.kernel.org", str)); \
 279 } while (0)
 280
 281 static int acpi_thermal_trips_update(struct acpi_thermal *tz, int flag)
 282 {
 283         acpi_status status = AE_OK;
 284         unsigned long long tmp;
 285         struct acpi_handle_list devices;
 286         int valid = 0;
 287         int i;
 288
 289         /* Critical Shutdown */
 290         if (flag & ACPI_TRIPS_CRITICAL) {
 291                 status = acpi_evaluate_integer(tz->device->handle,
 292                                 "_CRT", NULL, &tmp);
 293                 tz->trips.critical.temperature = tmp;
 294                 /*
 295                  * Treat freezing temperatures as invalid as well; some
 296                  * BIOSes return really low values and cause reboots at startup.
 297                  * Below zero (Celsius) values clearly aren't right for sure..
 298                  * ... so lets discard those as invalid.
 299                  */
 300                 if (ACPI_FAILURE(status)) {
 301                         tz->trips.critical.flags.valid = 0;
 302                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 303                                           "No critical threshold\n"));
 304                 } else if (tmp <= 2732) {
 305                         pr_warn(FW_BUG "Invalid critical threshold (%llu)\n",
 306                                 tmp);
 307                         tz->trips.critical.flags.valid = 0;
 308                 } else {
 309                         tz->trips.critical.flags.valid = 1;
 310                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 311                                           "Found critical threshold [%lu]\n",
 312                                           tz->trips.critical.temperature));
 313                 }
 314                 if (tz->trips.critical.flags.valid == 1) {
 315                         if (crt == -1) {
 316                                 tz->trips.critical.flags.valid = 0;
 317                         } else if (crt > 0) {
 318                                 unsigned long crt_k = CELSIUS_TO_KELVIN(crt);
 319                                 /*
 320                                  * Allow override critical threshold
 321                                  */
 322                                 if (crt_k > tz->trips.critical.temperature)
 323                                         pr_warn(PREFIX "Critical threshold %d C\n",
 324                                                 crt);
 325                                 tz->trips.critical.temperature = crt_k;
 326                         }
 327                 }
 328         }
 329
 330         /* Critical Sleep (optional) */
 331         if (flag & ACPI_TRIPS_HOT) {
 332                 status = acpi_evaluate_integer(tz->device->handle,
 333                                 "_HOT", NULL, &tmp);
 334                 if (ACPI_FAILURE(status)) {
 335                         tz->trips.hot.flags.valid = 0;
 336                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 337                                         "No hot threshold\n"));
 338                 } else {
 339                         tz->trips.hot.temperature = tmp;
 340                         tz->trips.hot.flags.valid = 1;
 341                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 342                                         "Found hot threshold [%lu]\n",
 343                                         tz->trips.hot.temperature));
 344                 }
 345         }
 346
 347         /* Passive (optional) */
 348         if (((flag & ACPI_TRIPS_PASSIVE) && tz->trips.passive.flags.valid) ||
 349                 (flag == ACPI_TRIPS_INIT)) {
 350                 valid = tz->trips.passive.flags.valid;
 351                 if (psv == -1) {
 352                         status = AE_SUPPORT;
 353                 } else if (psv > 0) {
 354                         tmp = CELSIUS_TO_KELVIN(psv);
 355                         status = AE_OK;
 356                 } else {
 357                         status = acpi_evaluate_integer(tz->device->handle,
 358                                 "_PSV", NULL, &tmp);
 359                 }
 360
 361                 if (ACPI_FAILURE(status))
 362                         tz->trips.passive.flags.valid = 0;
 363                 else {
 364                         tz->trips.passive.temperature = tmp;
 365                         tz->trips.passive.flags.valid = 1;
 366                         if (flag == ACPI_TRIPS_INIT) {
 367                                 status = acpi_evaluate_integer(
 368                                                 tz->device->handle, "_TC1",
 369                                                 NULL, &tmp);
 370                                 if (ACPI_FAILURE(status))
 371                                         tz->trips.passive.flags.valid = 0;
 372                                 else
 373                                         tz->trips.passive.tc1 = tmp;
 374                                 status = acpi_evaluate_integer(
 375                                                 tz->device->handle, "_TC2",
 376                                                 NULL, &tmp);
 377                                 if (ACPI_FAILURE(status))
 378                                         tz->trips.passive.flags.valid = 0;
 379                                 else
 380                                         tz->trips.passive.tc2 = tmp;
 381                                 status = acpi_evaluate_integer(
 382                                                 tz->device->handle, "_TSP",
 383                                                 NULL, &tmp);
 384                                 if (ACPI_FAILURE(status))
 385                                         tz->trips.passive.flags.valid = 0;
 386                                 else
 387                                         tz->trips.passive.tsp = tmp;
 388                         }
 389                 }
 390         }
 391         if ((flag & ACPI_TRIPS_DEVICES) && tz->trips.passive.flags.valid) {
 392                 memset(&devices, 0, sizeof(struct acpi_handle_list));
 393                 status = acpi_evaluate_reference(tz->device->handle, "_PSL",
 394                                                         NULL, &devices);
 395                 if (ACPI_FAILURE(status)) {
 396                         pr_warn(PREFIX "Invalid passive threshold\n");
 397                         tz->trips.passive.flags.valid = 0;
 398                 }
 399                 else
 400                         tz->trips.passive.flags.valid = 1;
 401
 402                 if (memcmp(&tz->trips.passive.devices, &devices,
 403                                 sizeof(struct acpi_handle_list))) {
 404                         memcpy(&tz->trips.passive.devices, &devices,
 405                                 sizeof(struct acpi_handle_list));
 406                         ACPI_THERMAL_TRIPS_EXCEPTION(flag, "device");
 407                 }
 408         }
 409         if ((flag & ACPI_TRIPS_PASSIVE) || (flag & ACPI_TRIPS_DEVICES)) {
 410                 if (valid != tz->trips.passive.flags.valid)
 411                                 ACPI_THERMAL_TRIPS_EXCEPTION(flag, "state");
 412         }
 413
 414         /* Active (optional) */
 415         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
 416                 char name[5] = { '_', 'A', 'C', ('0' + i), '\0' };
 417                 valid = tz->trips.active[i].flags.valid;
 418
 419                 if (act == -1)
 420                         break; /* disable all active trip points */
 421
 422                 if ((flag == ACPI_TRIPS_INIT) || ((flag & ACPI_TRIPS_ACTIVE) &&
 423                         tz->trips.active[i].flags.valid)) {
 424                         status = acpi_evaluate_integer(tz->device->handle,
 425                                                         name, NULL, &tmp);
 426                         if (ACPI_FAILURE(status)) {
 427                                 tz->trips.active[i].flags.valid = 0;
 428                                 if (i == 0)
 429                                         break;
 430                                 if (act <= 0)
 431                                         break;
 432                                 if (i == 1)
 433                                         tz->trips.active[0].temperature =
 434                                                 CELSIUS_TO_KELVIN(act);
 435                                 else
 436                                         /*
 437                                          * Don't allow override higher than
 438                                          * the next higher trip point
 439                                          */
 440                                         tz->trips.active[i - 1].temperature =
 441                                                 (tz->trips.active[i - 2].temperature <
 442                                                 CELSIUS_TO_KELVIN(act) ?
 443                                                 tz->trips.active[i - 2].temperature :
 444                                                 CELSIUS_TO_KELVIN(act));
 445                                 break;
 446                         } else {
 447                                 tz->trips.active[i].temperature = tmp;
 448                                 tz->trips.active[i].flags.valid = 1;
 449                         }
 450                 }
 451
 452                 name[2] = 'L';
 453                 if ((flag & ACPI_TRIPS_DEVICES) && tz->trips.active[i].flags.valid ) {
 454                         memset(&devices, 0, sizeof(struct acpi_handle_list));
 455                         status = acpi_evaluate_reference(tz->device->handle,
 456                                                 name, NULL, &devices);
 457                         if (ACPI_FAILURE(status)) {
 458                                 pr_warn(PREFIX "Invalid active%d threshold\n",
 459                                         i);
 460                                 tz->trips.active[i].flags.valid = 0;
 461                         }
 462                         else
 463                                 tz->trips.active[i].flags.valid = 1;
 464
 465                         if (memcmp(&tz->trips.active[i].devices, &devices,
 466                                         sizeof(struct acpi_handle_list))) {
 467                                 memcpy(&tz->trips.active[i].devices, &devices,
 468                                         sizeof(struct acpi_handle_list));
 469                                 ACPI_THERMAL_TRIPS_EXCEPTION(flag, "device");
 470                         }
 471                 }
 472                 if ((flag & ACPI_TRIPS_ACTIVE) || (flag & ACPI_TRIPS_DEVICES))
 473                         if (valid != tz->trips.active[i].flags.valid)
 474                                 ACPI_THERMAL_TRIPS_EXCEPTION(flag, "state");
 475
 476                 if (!tz->trips.active[i].flags.valid)
 477                         break;
 478         }
 479
 480         if ((flag & ACPI_TRIPS_DEVICES)
 481             && acpi_has_method(tz->device->handle, "_TZD")) {
 482                 memset(&devices, 0, sizeof(devices));
 483                 status = acpi_evaluate_reference(tz->device->handle, "_TZD",
 484                                                 NULL, &devices);
 485                 if (ACPI_SUCCESS(status)
 486                     && memcmp(&tz->devices, &devices, sizeof(devices))) {
 487                         tz->devices = devices;
 488                         ACPI_THERMAL_TRIPS_EXCEPTION(flag, "device");
 489                 }
 490         }
 491
 492         return 0;
 493 }
 494
 495 static int acpi_thermal_get_trip_points(struct acpi_thermal *tz)
 496 {
 497         int i, valid, ret = acpi_thermal_trips_update(tz, ACPI_TRIPS_INIT);
 498
 499         if (ret)
 500                 return ret;
 501
 502         valid = tz->trips.critical.flags.valid |
 503                 tz->trips.hot.flags.valid |
 504                 tz->trips.passive.flags.valid;
 505
 506         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++)
 507                 valid |= tz->trips.active[i].flags.valid;
 508
 509         if (!valid) {
 510                 pr_warn(FW_BUG "No valid trip found\n");
 511                 return -ENODEV;
 512         }
 513         return 0;
 514 }
 515
 516 static void acpi_thermal_check(void *data)
 517 {
 518         struct acpi_thermal *tz = data;
 519
 520         if (!tz->tz_enabled)
 521                 return;
 522
 523         thermal_zone_device_update(tz->thermal_zone);
 524 }
 525
 526 /* sys I/F for generic thermal sysfs support */
 527
 528 static int thermal_get_temp(struct thermal_zone_device *thermal, int *temp)
 529 {
 530         struct acpi_thermal *tz = thermal->devdata;
 531         int result;
 532
 533         if (!tz)
 534                 return -EINVAL;
 535
 536         result = acpi_thermal_get_temperature(tz);
 537         if (result)
 538                 return result;
 539
 540         *temp = DECI_KELVIN_TO_MILLICELSIUS_WITH_OFFSET(tz->temperature,
 541                                                         tz->kelvin_offset);
 542         return 0;
 543 }
 544
 545 static int thermal_get_mode(struct thermal_zone_device *thermal,
 546                                 enum thermal_device_mode *mode)
 547 {
 548         struct acpi_thermal *tz = thermal->devdata;
 549
 550         if (!tz)
 551                 return -EINVAL;
 552
 553         *mode = tz->tz_enabled ? THERMAL_DEVICE_ENABLED :
 554                 THERMAL_DEVICE_DISABLED;
 555
 556         return 0;
 557 }
 558
 559 static int thermal_set_mode(struct thermal_zone_device *thermal,
 560                                 enum thermal_device_mode mode)
 561 {
 562         struct acpi_thermal *tz = thermal->devdata;
 563         int enable;
 564
 565         if (!tz)
 566                 return -EINVAL;
 567
 568         /*
 569          * enable/disable thermal management from ACPI thermal driver
 570          */
 571         if (mode == THERMAL_DEVICE_ENABLED)
 572                 enable = 1;
 573         else if (mode == THERMAL_DEVICE_DISABLED) {
 574                 enable = 0;
 575                 pr_warn("thermal zone will be disabled\n");
 576         } else
 577                 return -EINVAL;
 578
 579         if (enable != tz->tz_enabled) {
 580                 tz->tz_enabled = enable;
 581                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 582                         "%s kernel ACPI thermal control\n",
 583                         tz->tz_enabled ? "Enable" : "Disable"));
 584                 acpi_thermal_check(tz);
 585         }
 586         return 0;
 587 }
 588
 589 static int thermal_get_trip_type(struct thermal_zone_device *thermal,
 590                                  int trip, enum thermal_trip_type *type)
 591 {
 592         struct acpi_thermal *tz = thermal->devdata;
 593         int i;
 594
 595         if (!tz || trip < 0)
 596                 return -EINVAL;
 597
 598         if (tz->trips.critical.flags.valid) {
 599                 if (!trip) {
 600                         *type = THERMAL_TRIP_CRITICAL;
 601                         return 0;
 602                 }
 603                 trip--;
 604         }
 605
 606         if (tz->trips.hot.flags.valid) {
 607                 if (!trip) {
 608                         *type = THERMAL_TRIP_HOT;
 609                         return 0;
 610                 }
 611                 trip--;
 612         }
 613
 614         if (tz->trips.passive.flags.valid) {
 615                 if (!trip) {
 616                         *type = THERMAL_TRIP_PASSIVE;
 617                         return 0;
 618                 }
 619                 trip--;
 620         }
 621
 622         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE &&
 623                 tz->trips.active[i].flags.valid; i++) {
 624                 if (!trip) {
 625                         *type = THERMAL_TRIP_ACTIVE;
 626                         return 0;
 627                 }
 628                 trip--;
 629         }
 630
 631         return -EINVAL;
 632 }
 633
 634 static int thermal_get_trip_temp(struct thermal_zone_device *thermal,
 635                                  int trip, int *temp)
 636 {
 637         struct acpi_thermal *tz = thermal->devdata;
 638         int i;
 639
 640         if (!tz || trip < 0)
 641                 return -EINVAL;
 642
 643         if (tz->trips.critical.flags.valid) {
 644                 if (!trip) {
 645                         *temp = DECI_KELVIN_TO_MILLICELSIUS_WITH_OFFSET(
 646                                 tz->trips.critical.temperature,
 647                                 tz->kelvin_offset);
 648                         return 0;
 649                 }
 650                 trip--;
 651         }
 652
 653         if (tz->trips.hot.flags.valid) {
 654                 if (!trip) {
 655                         *temp = DECI_KELVIN_TO_MILLICELSIUS_WITH_OFFSET(
 656                                 tz->trips.hot.temperature,
 657                                 tz->kelvin_offset);
 658                         return 0;
 659                 }
 660                 trip--;
 661         }
 662
 663         if (tz->trips.passive.flags.valid) {
 664                 if (!trip) {
 665                         *temp = DECI_KELVIN_TO_MILLICELSIUS_WITH_OFFSET(
 666                                 tz->trips.passive.temperature,
 667                                 tz->kelvin_offset);
 668                         return 0;
 669                 }
 670                 trip--;
 671         }
 672
 673         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE &&
 674                 tz->trips.active[i].flags.valid; i++) {
 675                 if (!trip) {
 676                         *temp = DECI_KELVIN_TO_MILLICELSIUS_WITH_OFFSET(
 677                                 tz->trips.active[i].temperature,
 678                                 tz->kelvin_offset);
 679                         return 0;
 680                 }
 681                 trip--;
 682         }
 683
 684         return -EINVAL;
 685 }
 686
 687 static int thermal_get_crit_temp(struct thermal_zone_device *thermal,
 688                                 int *temperature)
 689 {
 690         struct acpi_thermal *tz = thermal->devdata;
 691
 692         if (tz->trips.critical.flags.valid) {
 693                 *temperature = DECI_KELVIN_TO_MILLICELSIUS_WITH_OFFSET(
 694                                 tz->trips.critical.temperature,
 695                                 tz->kelvin_offset);
 696                 return 0;
 697         } else
 698                 return -EINVAL;
 699 }
 700
 701 static int thermal_get_trend(struct thermal_zone_device *thermal,
 702                                 int trip, enum thermal_trend *trend)
 703 {
 704         struct acpi_thermal *tz = thermal->devdata;
 705         enum thermal_trip_type type;
 706         int i;
 707
 708         if (thermal_get_trip_type(thermal, trip, &type))
 709                 return -EINVAL;
 710
 711         if (type == THERMAL_TRIP_ACTIVE) {
 712                 int trip_temp;
 713                 int temp = DECI_KELVIN_TO_MILLICELSIUS_WITH_OFFSET(
 714                                         tz->temperature, tz->kelvin_offset);
 715                 if (thermal_get_trip_temp(thermal, trip, &trip_temp))
 716                         return -EINVAL;
 717
 718                 if (temp > trip_temp) {
 719                         *trend = THERMAL_TREND_RAISING;
 720                         return 0;
 721                 } else {
 722                         /* Fall back on default trend */
 723                         return -EINVAL;
 724                 }
 725         }
 726
 727         /*
 728          * tz->temperature has already been updated by generic thermal layer,
 729          * before this callback being invoked
 730          */
 731         i = (tz->trips.passive.tc1 * (tz->temperature - tz->last_temperature))
 732                 + (tz->trips.passive.tc2
 733                 * (tz->temperature - tz->trips.passive.temperature));
 734
 735         if (i > 0)
 736                 *trend = THERMAL_TREND_RAISING;
 737         else if (i < 0)
 738                 *trend = THERMAL_TREND_DROPPING;
 739         else
 740                 *trend = THERMAL_TREND_STABLE;
 741         return 0;
 742 }
 743
 744
 745 static int thermal_notify(struct thermal_zone_device *thermal, int trip,
 746                            enum thermal_trip_type trip_type)
 747 {
 748         u8 type = 0;
 749         struct acpi_thermal *tz = thermal->devdata;
 750
 751         if (trip_type == THERMAL_TRIP_CRITICAL)
 752                 type = ACPI_THERMAL_NOTIFY_CRITICAL;
 753         else if (trip_type == THERMAL_TRIP_HOT)
 754                 type = ACPI_THERMAL_NOTIFY_HOT;
 755         else
 756                 return 0;
 757
 758         acpi_bus_generate_netlink_event(tz->device->pnp.device_class,
 759                                         dev_name(&tz->device->dev), type, 1);
 760
 761         if (trip_type == THERMAL_TRIP_CRITICAL && nocrt)
 762                 return 1;
 763
 764         return 0;
 765 }
 766
 767 static int acpi_thermal_cooling_device_cb(struct thermal_zone_device *thermal,
 768                                         struct thermal_cooling_device *cdev,
 769                                         bool bind)
 770 {
 771         struct acpi_device *device = cdev->devdata;
 772         struct acpi_thermal *tz = thermal->devdata;
 773         struct acpi_device *dev;
 774         acpi_status status;
 775         acpi_handle handle;
 776         int i;
 777         int j;
 778         int trip = -1;
 779         int result = 0;
 780
 781         if (tz->trips.critical.flags.valid)
 782                 trip++;
 783
 784         if (tz->trips.hot.flags.valid)
 785                 trip++;
 786
 787         if (tz->trips.passive.flags.valid) {
 788                 trip++;
 789                 for (i = 0; i < tz->trips.passive.devices.count;
 790                     i++) {
 791                         handle = tz->trips.passive.devices.handles[i];
 792                         status = acpi_bus_get_device(handle, &dev);
 793                         if (ACPI_FAILURE(status) || dev != device)
 794                                 continue;
 795                         if (bind)
 796                                 result =
 797                                         thermal_zone_bind_cooling_device
 798                                         (thermal, trip, cdev,
 799                                          THERMAL_NO_LIMIT, THERMAL_NO_LIMIT,
 800                                          THERMAL_WEIGHT_DEFAULT);
 801                         else
 802                                 result =
 803                                         thermal_zone_unbind_cooling_device
 804                                         (thermal, trip, cdev);
 805                         if (result)
 806                                 goto failed;
 807                 }
 808         }
 809
 810         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
 811                 if (!tz->trips.active[i].flags.valid)
 812                         break;
 813                 trip++;
 814                 for (j = 0;
 815                     j < tz->trips.active[i].devices.count;
 816                     j++) {
 817                         handle = tz->trips.active[i].devices.handles[j];
 818                         status = acpi_bus_get_device(handle, &dev);
 819                         if (ACPI_FAILURE(status) || dev != device)
 820                                 continue;
 821                         if (bind)
 822                                 result = thermal_zone_bind_cooling_device
 823                                         (thermal, trip, cdev,
 824                                          THERMAL_NO_LIMIT, THERMAL_NO_LIMIT,
 825                                          THERMAL_WEIGHT_DEFAULT);
 826                         else
 827                                 result = thermal_zone_unbind_cooling_device
 828                                         (thermal, trip, cdev);
 829                         if (result)
 830                                 goto failed;
 831                 }
 832         }
 833
 834         for (i = 0; i < tz->devices.count; i++) {
 835                 handle = tz->devices.handles[i];
 836                 status = acpi_bus_get_device(handle, &dev);
 837                 if (ACPI_SUCCESS(status) && (dev == device)) {
 838                         if (bind)
 839                                 result = thermal_zone_bind_cooling_device
 840                                                 (thermal, THERMAL_TRIPS_NONE,
 841                                                  cdev, THERMAL_NO_LIMIT,
 842                                                  THERMAL_NO_LIMIT,
 843                                                  THERMAL_WEIGHT_DEFAULT);
 844                         else
 845                                 result = thermal_zone_unbind_cooling_device
 846                                                 (thermal, THERMAL_TRIPS_NONE,
 847                                                  cdev);
 848                         if (result)
 849                                 goto failed;
 850                 }
 851         }
 852
 853 failed:
 854         return result;
 855 }
 856
 857 static int
 858 acpi_thermal_bind_cooling_device(struct thermal_zone_device *thermal,
 859                                         struct thermal_cooling_device *cdev)
 860 {
 861         return acpi_thermal_cooling_device_cb(thermal, cdev, true);
 862 }
 863
 864 static int
 865 acpi_thermal_unbind_cooling_device(struct thermal_zone_device *thermal,
 866                                         struct thermal_cooling_device *cdev)
 867 {
 868         return acpi_thermal_cooling_device_cb(thermal, cdev, false);
 869 }
 870
 871 static struct thermal_zone_device_ops acpi_thermal_zone_ops = {
 872         .bind = acpi_thermal_bind_cooling_device,
 873         .unbind = acpi_thermal_unbind_cooling_device,
 874         .get_temp = thermal_get_temp,
 875         .get_mode = thermal_get_mode,
 876         .set_mode = thermal_set_mode,
 877         .get_trip_type = thermal_get_trip_type,
 878         .get_trip_temp = thermal_get_trip_temp,
 879         .get_crit_temp = thermal_get_crit_temp,
 880         .get_trend = thermal_get_trend,
 881         .notify = thermal_notify,
 882 };
 883
 884 static int acpi_thermal_register_thermal_zone(struct acpi_thermal *tz)
 885 {
 886         int trips = 0;
 887         int result;
 888         acpi_status status;
 889         int i;
 890
 891         if (tz->trips.critical.flags.valid)
 892                 trips++;
 893
 894         if (tz->trips.hot.flags.valid)
 895                 trips++;
 896
 897         if (tz->trips.passive.flags.valid)
 898                 trips++;
 899
 900         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE &&
 901                         tz->trips.active[i].flags.valid; i++, trips++);
 902
 903         if (tz->trips.passive.flags.valid)
 904                 tz->thermal_zone =
 905                         thermal_zone_device_register("acpitz", trips, 0, tz,
 906                                                 &acpi_thermal_zone_ops, NULL,
 907                                                      tz->trips.passive.tsp*100,
 908                                                      tz->polling_frequency*100);
 909         else
 910                 tz->thermal_zone =
 911                         thermal_zone_device_register("acpitz", trips, 0, tz,
 912                                                 &acpi_thermal_zone_ops, NULL,
 913                                                 0, tz->polling_frequency*100);
 914         if (IS_ERR(tz->thermal_zone))
 915                 return -ENODEV;
 916
 917         result = sysfs_create_link(&tz->device->dev.kobj,
 918                                    &tz->thermal_zone->device.kobj, "thermal_zone");
 919         if (result)
 920                 return result;
 921
 922         result = sysfs_create_link(&tz->thermal_zone->device.kobj,
 923                                    &tz->device->dev.kobj, "device");
 924         if (result)
 925                 return result;
 926
 927         status =  acpi_bus_attach_private_data(tz->device->handle,
 928                                                tz->thermal_zone);
 929         if (ACPI_FAILURE(status))
 930                 return -ENODEV;
 931
 932         tz->tz_enabled = 1;
 933
 934         dev_info(&tz->device->dev, "registered as thermal_zone%d\n",
 935                  tz->thermal_zone->id);
 936         return 0;
 937 }
 938
 939 static void acpi_thermal_unregister_thermal_zone(struct acpi_thermal *tz)
 940 {
 941         sysfs_remove_link(&tz->device->dev.kobj, "thermal_zone");
 942         sysfs_remove_link(&tz->thermal_zone->device.kobj, "device");
 943         thermal_zone_device_unregister(tz->thermal_zone);
 944         tz->thermal_zone = NULL;
 945         acpi_bus_detach_private_data(tz->device->handle);
 946 }
 947
 948
 949 /* --------------------------------------------------------------------------
 950                                  Driver Interface
 951    -------------------------------------------------------------------------- */
 952
 953 static void acpi_thermal_notify(struct acpi_device *device, u32 event)
 954 {
 955         struct acpi_thermal *tz = acpi_driver_data(device);
 956
 957
 958         if (!tz)
 959                 return;
 960
 961         switch (event) {
 962         case ACPI_THERMAL_NOTIFY_TEMPERATURE:
 963                 acpi_thermal_check(tz);
 964                 break;
 965         case ACPI_THERMAL_NOTIFY_THRESHOLDS:
 966                 acpi_thermal_trips_update(tz, ACPI_TRIPS_REFRESH_THRESHOLDS);
 967                 acpi_thermal_check(tz);
 968                 acpi_bus_generate_netlink_event(device->pnp.device_class,
 969                                                   dev_name(&device->dev), event, 0);
 970                 break;
 971         case ACPI_THERMAL_NOTIFY_DEVICES:
 972                 acpi_thermal_trips_update(tz, ACPI_TRIPS_REFRESH_DEVICES);
 973                 acpi_thermal_check(tz);
 974                 acpi_bus_generate_netlink_event(device->pnp.device_class,
 975                                                   dev_name(&device->dev), event, 0);
 976                 break;
 977         default:
 978                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 979                                   "Unsupported event [0x%x]\n", event));
 980                 break;
 981         }
 982 }
 983
 984 /*
 985  * On some platforms, the AML code has dependency about
 986  * the evaluating order of _TMP and _CRT/_HOT/_PSV/_ACx.
 987  * 1. On HP Pavilion G4-1016tx, _TMP must be invoked after
 988  *    /_CRT/_HOT/_PSV/_ACx, or else system will be power off.
 989  * 2. On HP Compaq 6715b/6715s, the return value of _PSV is 0
 990  *    if _TMP has never been evaluated.
 991  *
 992  * As this dependency is totally transparent to OS, evaluate
 993  * all of them once, in the order of _CRT/_HOT/_PSV/_ACx,
 994  * _TMP, before they are actually used.
 995  */
 996 static void acpi_thermal_aml_dependency_fix(struct acpi_thermal *tz)
 997 {
 998         acpi_handle handle = tz->device->handle;
 999         unsigned long long value;
1000         int i;
1001
1002         acpi_evaluate_integer(handle, "_CRT", NULL, &value);
1003         acpi_evaluate_integer(handle, "_HOT", NULL, &value);
1004         acpi_evaluate_integer(handle, "_PSV", NULL, &value);
1005         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
1006                 char name[5] = { '_', 'A', 'C', ('0' + i), '\0' };
1007                 acpi_status status;
1008
1009                 status = acpi_evaluate_integer(handle, name, NULL, &value);
1010                 if (status == AE_NOT_FOUND)
1011                         break;
1012         }
1013         acpi_evaluate_integer(handle, "_TMP", NULL, &value);
1014 }
1015
1016 static int acpi_thermal_get_info(struct acpi_thermal *tz)
1017 {
1018         int result = 0;
1019
1020
1021         if (!tz)
1022                 return -EINVAL;
1023
1024         acpi_thermal_aml_dependency_fix(tz);
1025
1026         /* Get trip points [_CRT, _PSV, etc.] (required) */
1027         result = acpi_thermal_get_trip_points(tz);
1028         if (result)
1029                 return result;
1030
1031         /* Get temperature [_TMP] (required) */
1032         result = acpi_thermal_get_temperature(tz);
1033         if (result)
1034                 return result;
1035
1036         /* Set the cooling mode [_SCP] to active cooling (default) */
1037         result = acpi_thermal_set_cooling_mode(tz, ACPI_THERMAL_MODE_ACTIVE);
1038         if (!result)
1039                 tz->flags.cooling_mode = 1;
1040
1041         /* Get default polling frequency [_TZP] (optional) */
1042         if (tzp)
1043                 tz->polling_frequency = tzp;
1044         else
1045                 acpi_thermal_get_polling_frequency(tz);
1046
1047         return 0;
1048 }
1049
1050 /*
1051  * The exact offset between Kelvin and degree Celsius is 273.15. However ACPI
1052  * handles temperature values with a single decimal place. As a consequence,
1053  * some implementations use an offset of 273.1 and others use an offset of
1054  * 273.2. Try to find out which one is being used, to present the most
1055  * accurate and visually appealing number.
1056  *
1057  * The heuristic below should work for all ACPI thermal zones which have a
1058  * critical trip point with a value being a multiple of 0.5 degree Celsius.
1059  */
1060 static void acpi_thermal_guess_offset(struct acpi_thermal *tz)
1061 {
1062         if (tz->trips.critical.flags.valid &&
1063             (tz->trips.critical.temperature % 5) == 1)
1064                 tz->kelvin_offset = 2731;
1065         else
1066                 tz->kelvin_offset = 2732;
1067 }
1068
1069 static void acpi_thermal_check_fn(struct work_struct *work)
1070 {
1071         struct acpi_thermal *tz = container_of(work, struct acpi_thermal,
1072                                                thermal_check_work);
1073         acpi_thermal_check(tz);
1074 }
1075
1076 static int acpi_thermal_add(struct acpi_device *device)
1077 {
1078         int result = 0;
1079         struct acpi_thermal *tz = NULL;
1080
1081
1082         if (!device)
1083                 return -EINVAL;
1084
1085         tz = kzalloc(sizeof(struct acpi_thermal), GFP_KERNEL);
1086         if (!tz)
1087                 return -ENOMEM;
1088
1089         tz->device = device;
1090         strcpy(tz->name, device->pnp.bus_id);
1091         strcpy(acpi_device_name(device), ACPI_THERMAL_DEVICE_NAME);
1092         strcpy(acpi_device_class(device), ACPI_THERMAL_CLASS);
1093         device->driver_data = tz;
1094
1095         result = acpi_thermal_get_info(tz);
1096         if (result)
1097                 goto free_memory;
1098
1099         acpi_thermal_guess_offset(tz);
1100
1101         result = acpi_thermal_register_thermal_zone(tz);
1102         if (result)
1103                 goto free_memory;
1104
1105         INIT_WORK(&tz->thermal_check_work, acpi_thermal_check_fn);
1106
1107         pr_info(PREFIX "%s [%s] (%ld C)\n", acpi_device_name(device),
1108                 acpi_device_bid(device), KELVIN_TO_CELSIUS(tz->temperature));
1109         goto end;
1110
1111 free_memory:
1112         kfree(tz);
1113 end:
1114         return result;
1115 }
1116
1117 static int acpi_thermal_remove(struct acpi_device *device)
1118 {
1119         struct acpi_thermal *tz = NULL;
1120
1121         if (!device || !acpi_driver_data(device))
1122                 return -EINVAL;
1123
1124         flush_workqueue(acpi_thermal_pm_queue);
1125         tz = acpi_driver_data(device);
1126
1127         acpi_thermal_unregister_thermal_zone(tz);
1128         kfree(tz);
1129         return 0;
1130 }
1131
1132 #ifdef CONFIG_PM_SLEEP
1133 static int acpi_thermal_suspend(struct device *dev)
1134 {
1135         /* Make sure the previously queued thermal check work has been done */
1136         flush_workqueue(acpi_thermal_pm_queue);
1137         return 0;
1138 }
1139
1140 static int acpi_thermal_resume(struct device *dev)
1141 {
1142         struct acpi_thermal *tz;
1143         int i, j, power_state, result;
1144
1145         if (!dev)
1146                 return -EINVAL;
1147
1148         tz = acpi_driver_data(to_acpi_device(dev));
1149         if (!tz)
1150                 return -EINVAL;
1151
1152         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
1153                 if (!(&tz->trips.active[i]))
1154                         break;
1155                 if (!tz->trips.active[i].flags.valid)
1156                         break;
1157                 tz->trips.active[i].flags.enabled = 1;
1158                 for (j = 0; j < tz->trips.active[i].devices.count; j++) {
1159                         result = acpi_bus_update_power(
1160                                         tz->trips.active[i].devices.handles[j],
1161                                         &power_state);
1162                         if (result || (power_state != ACPI_STATE_D0)) {
1163                                 tz->trips.active[i].flags.enabled = 0;
1164                                 break;
1165                         }
1166                 }
1167                 tz->state.active |= tz->trips.active[i].flags.enabled;
1168         }
1169
1170         queue_work(acpi_thermal_pm_queue, &tz->thermal_check_work);
1171
1172         return AE_OK;
1173 }
1174 #endif
1175
1176 static int thermal_act(const struct dmi_system_id *d) {
1177
1178         if (act == 0) {
1179                 pr_notice(PREFIX "%s detected: "
1180                           "disabling all active thermal trip points\n", d->ident);
1181                 act = -1;
1182         }
1183         return 0;
1184 }
1185 static int thermal_nocrt(const struct dmi_system_id *d) {
1186
1187         pr_notice(PREFIX "%s detected: "
1188                   "disabling all critical thermal trip point actions.\n", d->ident);
1189         nocrt = 1;
1190         return 0;
1191 }
1192 static int thermal_tzp(const struct dmi_system_id *d) {
1193
1194         if (tzp == 0) {
1195                 pr_notice(PREFIX "%s detected: "
1196                           "enabling thermal zone polling\n", d->ident);
1197                 tzp = 300;      /* 300 dS = 30 Seconds */
1198         }
1199         return 0;
1200 }
1201 static int thermal_psv(const struct dmi_system_id *d) {
1202
1203         if (psv == 0) {
1204                 pr_notice(PREFIX "%s detected: "
1205                           "disabling all passive thermal trip points\n", d->ident);
1206                 psv = -1;
1207         }
1208         return 0;
1209 }
1210
1211 static struct dmi_system_id thermal_dmi_table[] __initdata = {
1212         /*
1213          * Award BIOS on this AOpen makes thermal control almost worthless.
1214          * http://bugzilla.kernel.org/show_bug.cgi?id=8842
1215          */
1216         {
1217          .callback = thermal_act,
1218          .ident = "AOpen i915GMm-HFS",
1219          .matches = {
1220                 DMI_MATCH(DMI_BOARD_VENDOR, "AOpen"),
1221                 DMI_MATCH(DMI_BOARD_NAME, "i915GMm-HFS"),
1222                 },
1223         },
1224         {
1225          .callback = thermal_psv,
1226          .ident = "AOpen i915GMm-HFS",
1227          .matches = {
1228                 DMI_MATCH(DMI_BOARD_VENDOR, "AOpen"),
1229                 DMI_MATCH(DMI_BOARD_NAME, "i915GMm-HFS"),
1230                 },
1231         },
1232         {
1233          .callback = thermal_tzp,
1234          .ident = "AOpen i915GMm-HFS",
1235          .matches = {
1236                 DMI_MATCH(DMI_BOARD_VENDOR, "AOpen"),
1237                 DMI_MATCH(DMI_BOARD_NAME, "i915GMm-HFS"),
1238                 },
1239         },
1240         {
1241          .callback = thermal_nocrt,
1242          .ident = "Gigabyte GA-7ZX",
1243          .matches = {
1244                 DMI_MATCH(DMI_BOARD_VENDOR, "Gigabyte Technology Co., Ltd."),
1245                 DMI_MATCH(DMI_BOARD_NAME, "7ZX"),
1246                 },
1247         },
1248         {}
1249 };
1250
1251 static int __init acpi_thermal_init(void)
1252 {
1253         int result = 0;
1254
1255         dmi_check_system(thermal_dmi_table);
1256
1257         if (off) {
1258                 pr_notice(PREFIX "thermal control disabled\n");
1259                 return -ENODEV;
1260         }
1261
1262         acpi_thermal_pm_queue = create_workqueue("acpi_thermal_pm");
1263         if (!acpi_thermal_pm_queue)
1264                 return -ENODEV;
1265
1266         result = acpi_bus_register_driver(&acpi_thermal_driver);
1267         if (result < 0) {
1268                 destroy_workqueue(acpi_thermal_pm_queue);
1269                 return -ENODEV;
1270         }
1271
1272         return 0;
1273 }
1274
1275 static void __exit acpi_thermal_exit(void)
1276 {
1277         acpi_bus_unregister_driver(&acpi_thermal_driver);
1278         destroy_workqueue(acpi_thermal_pm_queue);
1279
1280         return;
1281 }
1282
1283 module_init(acpi_thermal_init);
1284 module_exit(acpi_thermal_exit);