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  *  You should have received a copy of the GNU General Public License along
  20  *  with this program; if not, write to the Free Software Foundation, Inc.,
  21  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  22  *
  23  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  24  *
  25  *  This driver fully implements the ACPI thermal policy as described in the
  26  *  ACPI 2.0 Specification.
  27  *
  28  *  TBD: 1. Implement passive cooling hysteresis.
  29  *       2. Enhance passive cooling (CPU) states/limit interface to support
  30  *          concepts of 'multiple limiters', upper/lower limits, etc.
  31  *
  32  */
  33
  34 #include <linux/kernel.h>
  35 #include <linux/module.h>
  36 #include <linux/dmi.h>
  37 #include <linux/init.h>
  38 #include <linux/slab.h>
  39 #include <linux/types.h>
  40 #include <linux/jiffies.h>
  41 #include <linux/kmod.h>
  42 #include <linux/reboot.h>
  43 #include <linux/device.h>
  44 #include <linux/thermal.h>
  45 #include <linux/acpi.h>
  46 #include <linux/workqueue.h>
  47 #include <asm/uaccess.h>
  48
  49 #define PREFIX "ACPI: "
  50
  51 #define ACPI_THERMAL_CLASS              "thermal_zone"
  52 #define ACPI_THERMAL_DEVICE_NAME        "Thermal Zone"
  53 #define ACPI_THERMAL_NOTIFY_TEMPERATURE 0x80
  54 #define ACPI_THERMAL_NOTIFY_THRESHOLDS  0x81
  55 #define ACPI_THERMAL_NOTIFY_DEVICES     0x82
  56 #define ACPI_THERMAL_NOTIFY_CRITICAL    0xF0
  57 #define ACPI_THERMAL_NOTIFY_HOT         0xF1
  58 #define ACPI_THERMAL_MODE_ACTIVE        0x00
  59
  60 #define ACPI_THERMAL_MAX_ACTIVE 10
  61 #define ACPI_THERMAL_MAX_LIMIT_STR_LEN 65
  62
  63 #define _COMPONENT              ACPI_THERMAL_COMPONENT
  64 ACPI_MODULE_NAME("thermal");
  65
  66 MODULE_AUTHOR("Paul Diefenbaugh");
  67 MODULE_DESCRIPTION("ACPI Thermal Zone Driver");
  68 MODULE_LICENSE("GPL");
  69
  70 static int act;
  71 module_param(act, int, 0644);
  72 MODULE_PARM_DESC(act, "Disable or override all lowest active trip points.");
  73
  74 static int crt;
  75 module_param(crt, int, 0644);
  76 MODULE_PARM_DESC(crt, "Disable or lower all critical trip points.");
  77
  78 static int tzp;
  79 module_param(tzp, int, 0444);
  80 MODULE_PARM_DESC(tzp, "Thermal zone polling frequency, in 1/10 seconds.");
  81
  82 static int nocrt;
  83 module_param(nocrt, int, 0);
  84 MODULE_PARM_DESC(nocrt, "Set to take no action upon ACPI thermal zone critical trips points.");
  85
  86 static int off;
  87 module_param(off, int, 0);
  88 MODULE_PARM_DESC(off, "Set to disable ACPI thermal support.");
  89
  90 static int psv;
  91 module_param(psv, int, 0644);
  92 MODULE_PARM_DESC(psv, "Disable or override all passive trip points.");
  93
  94 static struct workqueue_struct *acpi_thermal_pm_queue;
  95
  96 static int acpi_thermal_add(struct acpi_device *device);
  97 static int acpi_thermal_remove(struct acpi_device *device);
  98 static void acpi_thermal_notify(struct acpi_device *device, u32 event);
  99
 100 static const struct acpi_device_id  thermal_device_ids[] = {
 101         {ACPI_THERMAL_HID, 0},
 102         {"", 0},
 103 };
 104 MODULE_DEVICE_TABLE(acpi, thermal_device_ids);
 105
 106 #ifdef CONFIG_PM_SLEEP
 107 static int acpi_thermal_suspend(struct device *dev);
 108 static int acpi_thermal_resume(struct device *dev);
 109 #else
 110 #define acpi_thermal_suspend NULL
 111 #define acpi_thermal_resume NULL
 112 #endif
 113 static SIMPLE_DEV_PM_OPS(acpi_thermal_pm, acpi_thermal_suspend, acpi_thermal_resume);
 114
 115 static struct acpi_driver acpi_thermal_driver = {
 116         .name = "thermal",
 117         .class = ACPI_THERMAL_CLASS,
 118         .ids = thermal_device_ids,
 119         .ops = {
 120                 .add = acpi_thermal_add,
 121                 .remove = acpi_thermal_remove,
 122                 .notify = acpi_thermal_notify,
 123                 },
 124         .drv.pm = &acpi_thermal_pm,
 125 };
 126
 127 struct acpi_thermal_state {
 128         u8 critical:1;
 129         u8 hot:1;
 130         u8 passive:1;
 131         u8 active:1;
 132         u8 reserved:4;
 133         int active_index;
 134 };
 135
 136 struct acpi_thermal_state_flags {
 137         u8 valid:1;
 138         u8 enabled:1;
 139         u8 reserved:6;
 140 };
 141
 142 struct acpi_thermal_critical {
 143         struct acpi_thermal_state_flags flags;
 144         unsigned long temperature;
 145 };
 146
 147 struct acpi_thermal_hot {
 148         struct acpi_thermal_state_flags flags;
 149         unsigned long temperature;
 150 };
 151
 152 struct acpi_thermal_passive {
 153         struct acpi_thermal_state_flags flags;
 154         unsigned long temperature;
 155         unsigned long tc1;
 156         unsigned long tc2;
 157         unsigned long tsp;
 158         struct acpi_handle_list devices;
 159 };
 160
 161 struct acpi_thermal_active {
 162         struct acpi_thermal_state_flags flags;
 163         unsigned long temperature;
 164         struct acpi_handle_list devices;
 165 };
 166
 167 struct acpi_thermal_trips {
 168         struct acpi_thermal_critical critical;
 169         struct acpi_thermal_hot hot;
 170         struct acpi_thermal_passive passive;
 171         struct acpi_thermal_active active[ACPI_THERMAL_MAX_ACTIVE];
 172 };
 173
 174 struct acpi_thermal_flags {
 175         u8 cooling_mode:1;      /* _SCP */
 176         u8 devices:1;           /* _TZD */
 177         u8 reserved:6;
 178 };
 179
 180 struct acpi_thermal {
 181         struct acpi_device * device;
 182         acpi_bus_id name;
 183         unsigned long temperature;
 184         unsigned long last_temperature;
 185         unsigned long polling_frequency;
 186         volatile u8 zombie;
 187         struct acpi_thermal_flags flags;
 188         struct acpi_thermal_state state;
 189         struct acpi_thermal_trips trips;
 190         struct acpi_handle_list devices;
 191         struct thermal_zone_device *thermal_zone;
 192         int tz_enabled;
 193         int kelvin_offset;
 194         struct work_struct thermal_check_work;
 195 };
 196
 197 /* --------------------------------------------------------------------------
 198                              Thermal Zone Management
 199    -------------------------------------------------------------------------- */
 200
 201 static int acpi_thermal_get_temperature(struct acpi_thermal *tz)
 202 {
 203         acpi_status status = AE_OK;
 204         unsigned long long tmp;
 205
 206         if (!tz)
 207                 return -EINVAL;
 208
 209         tz->last_temperature = tz->temperature;
 210
 211         status = acpi_evaluate_integer(tz->device->handle, "_TMP", NULL, &tmp);
 212         if (ACPI_FAILURE(status))
 213                 return -ENODEV;
 214
 215         tz->temperature = tmp;
 216         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Temperature is %lu dK\n",
 217                           tz->temperature));
 218
 219         return 0;
 220 }
 221
 222 static int acpi_thermal_get_polling_frequency(struct acpi_thermal *tz)
 223 {
 224         acpi_status status = AE_OK;
 225         unsigned long long tmp;
 226
 227         if (!tz)
 228                 return -EINVAL;
 229
 230         status = acpi_evaluate_integer(tz->device->handle, "_TZP", NULL, &tmp);
 231         if (ACPI_FAILURE(status))
 232                 return -ENODEV;
 233
 234         tz->polling_frequency = tmp;
 235         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Polling frequency is %lu dS\n",
 236                           tz->polling_frequency));
 237
 238         return 0;
 239 }
 240
 241 static int acpi_thermal_set_cooling_mode(struct acpi_thermal *tz, int mode)
 242 {
 243         if (!tz)
 244                 return -EINVAL;
 245
 246         if (!acpi_has_method(tz->device->handle, "_SCP")) {
 247                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "_SCP not present\n"));
 248                 return -ENODEV;
 249         } else if (ACPI_FAILURE(acpi_execute_simple_method(tz->device->handle,
 250                                                            "_SCP", mode))) {
 251                 return -ENODEV;
 252         }
 253
 254         return 0;
 255 }
 256
 257 #define ACPI_TRIPS_CRITICAL     0x01
 258 #define ACPI_TRIPS_HOT          0x02
 259 #define ACPI_TRIPS_PASSIVE      0x04
 260 #define ACPI_TRIPS_ACTIVE       0x08
 261 #define ACPI_TRIPS_DEVICES      0x10
 262
 263 #define ACPI_TRIPS_REFRESH_THRESHOLDS   (ACPI_TRIPS_PASSIVE | ACPI_TRIPS_ACTIVE)
 264 #define ACPI_TRIPS_REFRESH_DEVICES      ACPI_TRIPS_DEVICES
 265
 266 #define ACPI_TRIPS_INIT      (ACPI_TRIPS_CRITICAL | ACPI_TRIPS_HOT |    \
 267                               ACPI_TRIPS_PASSIVE | ACPI_TRIPS_ACTIVE |  \
 268                               ACPI_TRIPS_DEVICES)
 269
 270 /*
 271  * This exception is thrown out in two cases:
 272  * 1.An invalid trip point becomes invalid or a valid trip point becomes invalid
 273  *   when re-evaluating the AML code.
 274  * 2.TODO: Devices listed in _PSL, _ALx, _TZD may change.
 275  *   We need to re-bind the cooling devices of a thermal zone when this occurs.
 276  */
 277 #define ACPI_THERMAL_TRIPS_EXCEPTION(flags, str)        \
 278 do {    \
 279         if (flags != ACPI_TRIPS_INIT)   \
 280                 ACPI_EXCEPTION((AE_INFO, AE_ERROR,      \
 281                 "ACPI thermal trip point %s changed\n"  \
 282                 "Please send acpidump to linux-acpi@vger.kernel.org", str)); \
 283 } while (0)
 284
 285 static int acpi_thermal_trips_update(struct acpi_thermal *tz, int flag)
 286 {
 287         acpi_status status = AE_OK;
 288         unsigned long long tmp;
 289         struct acpi_handle_list devices;
 290         int valid = 0;
 291         int i;
 292
 293         /* Critical Shutdown */
 294         if (flag & ACPI_TRIPS_CRITICAL) {
 295                 status = acpi_evaluate_integer(tz->device->handle,
 296                                 "_CRT", NULL, &tmp);
 297                 tz->trips.critical.temperature = tmp;
 298                 /*
 299                  * Treat freezing temperatures as invalid as well; some
 300                  * BIOSes return really low values and cause reboots at startup.
 301                  * Below zero (Celsius) values clearly aren't right for sure..
 302                  * ... so lets discard those as invalid.
 303                  */
 304                 if (ACPI_FAILURE(status)) {
 305                         tz->trips.critical.flags.valid = 0;
 306                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 307                                           "No critical threshold\n"));
 308                 } else if (tmp <= 2732) {
 309                         pr_warn(FW_BUG "Invalid critical threshold (%llu)\n",
 310                                 tmp);
 311                         tz->trips.critical.flags.valid = 0;
 312                 } else {
 313                         tz->trips.critical.flags.valid = 1;
 314                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 315                                           "Found critical threshold [%lu]\n",
 316                                           tz->trips.critical.temperature));
 317                 }
 318                 if (tz->trips.critical.flags.valid == 1) {
 319                         if (crt == -1) {
 320                                 tz->trips.critical.flags.valid = 0;
 321                         } else if (crt > 0) {
 322                                 unsigned long crt_k = CELSIUS_TO_KELVIN(crt);
 323                                 /*
 324                                  * Allow override critical threshold
 325                                  */
 326                                 if (crt_k > tz->trips.critical.temperature)
 327                                         pr_warn(PREFIX "Critical threshold %d C\n",
 328                                                 crt);
 329                                 tz->trips.critical.temperature = crt_k;
 330                         }
 331                 }
 332         }
 333
 334         /* Critical Sleep (optional) */
 335         if (flag & ACPI_TRIPS_HOT) {
 336                 status = acpi_evaluate_integer(tz->device->handle,
 337                                 "_HOT", NULL, &tmp);
 338                 if (ACPI_FAILURE(status)) {
 339                         tz->trips.hot.flags.valid = 0;
 340                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 341                                         "No hot threshold\n"));
 342                 } else {
 343                         tz->trips.hot.temperature = tmp;
 344                         tz->trips.hot.flags.valid = 1;
 345                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 346                                         "Found hot threshold [%lu]\n",
 347                                         tz->trips.hot.temperature));
 348                 }
 349         }
 350
 351         /* Passive (optional) */
 352         if (((flag & ACPI_TRIPS_PASSIVE) && tz->trips.passive.flags.valid) ||
 353                 (flag == ACPI_TRIPS_INIT)) {
 354                 valid = tz->trips.passive.flags.valid;
 355                 if (psv == -1) {
 356                         status = AE_SUPPORT;
 357                 } else if (psv > 0) {
 358                         tmp = CELSIUS_TO_KELVIN(psv);
 359                         status = AE_OK;
 360                 } else {
 361                         status = acpi_evaluate_integer(tz->device->handle,
 362                                 "_PSV", NULL, &tmp);
 363                 }
 364
 365                 if (ACPI_FAILURE(status))
 366                         tz->trips.passive.flags.valid = 0;
 367                 else {
 368                         tz->trips.passive.temperature = tmp;
 369                         tz->trips.passive.flags.valid = 1;
 370                         if (flag == ACPI_TRIPS_INIT) {
 371                                 status = acpi_evaluate_integer(
 372                                                 tz->device->handle, "_TC1",
 373                                                 NULL, &tmp);
 374                                 if (ACPI_FAILURE(status))
 375                                         tz->trips.passive.flags.valid = 0;
 376                                 else
 377                                         tz->trips.passive.tc1 = tmp;
 378                                 status = acpi_evaluate_integer(
 379                                                 tz->device->handle, "_TC2",
 380                                                 NULL, &tmp);
 381                                 if (ACPI_FAILURE(status))
 382                                         tz->trips.passive.flags.valid = 0;
 383                                 else
 384                                         tz->trips.passive.tc2 = tmp;
 385                                 status = acpi_evaluate_integer(
 386                                                 tz->device->handle, "_TSP",
 387                                                 NULL, &tmp);
 388                                 if (ACPI_FAILURE(status))
 389                                         tz->trips.passive.flags.valid = 0;
 390                                 else
 391                                         tz->trips.passive.tsp = tmp;
 392                         }
 393                 }
 394         }
 395         if ((flag & ACPI_TRIPS_DEVICES) && tz->trips.passive.flags.valid) {
 396                 memset(&devices, 0, sizeof(struct acpi_handle_list));
 397                 status = acpi_evaluate_reference(tz->device->handle, "_PSL",
 398                                                         NULL, &devices);
 399                 if (ACPI_FAILURE(status)) {
 400                         pr_warn(PREFIX "Invalid passive threshold\n");
 401                         tz->trips.passive.flags.valid = 0;
 402                 }
 403                 else
 404                         tz->trips.passive.flags.valid = 1;
 405
 406                 if (memcmp(&tz->trips.passive.devices, &devices,
 407                                 sizeof(struct acpi_handle_list))) {
 408                         memcpy(&tz->trips.passive.devices, &devices,
 409                                 sizeof(struct acpi_handle_list));
 410                         ACPI_THERMAL_TRIPS_EXCEPTION(flag, "device");
 411                 }
 412         }
 413         if ((flag & ACPI_TRIPS_PASSIVE) || (flag & ACPI_TRIPS_DEVICES)) {
 414                 if (valid != tz->trips.passive.flags.valid)
 415                                 ACPI_THERMAL_TRIPS_EXCEPTION(flag, "state");
 416         }
 417
 418         /* Active (optional) */
 419         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
 420                 char name[5] = { '_', 'A', 'C', ('0' + i), '\0' };
 421                 valid = tz->trips.active[i].flags.valid;
 422
 423                 if (act == -1)
 424                         break; /* disable all active trip points */
 425
 426                 if ((flag == ACPI_TRIPS_INIT) || ((flag & ACPI_TRIPS_ACTIVE) &&
 427                         tz->trips.active[i].flags.valid)) {
 428                         status = acpi_evaluate_integer(tz->device->handle,
 429                                                         name, NULL, &tmp);
 430                         if (ACPI_FAILURE(status)) {
 431                                 tz->trips.active[i].flags.valid = 0;
 432                                 if (i == 0)
 433                                         break;
 434                                 if (act <= 0)
 435                                         break;
 436                                 if (i == 1)
 437                                         tz->trips.active[0].temperature =
 438                                                 CELSIUS_TO_KELVIN(act);
 439                                 else
 440                                         /*
 441                                          * Don't allow override higher than
 442                                          * the next higher trip point
 443                                          */
 444                                         tz->trips.active[i - 1].temperature =
 445                                                 (tz->trips.active[i - 2].temperature <
 446                                                 CELSIUS_TO_KELVIN(act) ?
 447                                                 tz->trips.active[i - 2].temperature :
 448                                                 CELSIUS_TO_KELVIN(act));
 449                                 break;
 450                         } else {
 451                                 tz->trips.active[i].temperature = tmp;
 452                                 tz->trips.active[i].flags.valid = 1;
 453                         }
 454                 }
 455
 456                 name[2] = 'L';
 457                 if ((flag & ACPI_TRIPS_DEVICES) && tz->trips.active[i].flags.valid ) {
 458                         memset(&devices, 0, sizeof(struct acpi_handle_list));
 459                         status = acpi_evaluate_reference(tz->device->handle,
 460                                                 name, NULL, &devices);
 461                         if (ACPI_FAILURE(status)) {
 462                                 pr_warn(PREFIX "Invalid active%d threshold\n",
 463                                         i);
 464                                 tz->trips.active[i].flags.valid = 0;
 465                         }
 466                         else
 467                                 tz->trips.active[i].flags.valid = 1;
 468
 469                         if (memcmp(&tz->trips.active[i].devices, &devices,
 470                                         sizeof(struct acpi_handle_list))) {
 471                                 memcpy(&tz->trips.active[i].devices, &devices,
 472                                         sizeof(struct acpi_handle_list));
 473                                 ACPI_THERMAL_TRIPS_EXCEPTION(flag, "device");
 474                         }
 475                 }
 476                 if ((flag & ACPI_TRIPS_ACTIVE) || (flag & ACPI_TRIPS_DEVICES))
 477                         if (valid != tz->trips.active[i].flags.valid)
 478                                 ACPI_THERMAL_TRIPS_EXCEPTION(flag, "state");
 479
 480                 if (!tz->trips.active[i].flags.valid)
 481                         break;
 482         }
 483
 484         if ((flag & ACPI_TRIPS_DEVICES)
 485             && acpi_has_method(tz->device->handle, "_TZD")) {
 486                 memset(&devices, 0, sizeof(devices));
 487                 status = acpi_evaluate_reference(tz->device->handle, "_TZD",
 488                                                 NULL, &devices);
 489                 if (ACPI_SUCCESS(status)
 490                     && memcmp(&tz->devices, &devices, sizeof(devices))) {
 491                         tz->devices = devices;
 492                         ACPI_THERMAL_TRIPS_EXCEPTION(flag, "device");
 493                 }
 494         }
 495
 496         return 0;
 497 }
 498
 499 static int acpi_thermal_get_trip_points(struct acpi_thermal *tz)
 500 {
 501         int i, valid, ret = acpi_thermal_trips_update(tz, ACPI_TRIPS_INIT);
 502
 503         if (ret)
 504                 return ret;
 505
 506         valid = tz->trips.critical.flags.valid |
 507                 tz->trips.hot.flags.valid |
 508                 tz->trips.passive.flags.valid;
 509
 510         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++)
 511                 valid |= tz->trips.active[i].flags.valid;
 512
 513         if (!valid) {
 514                 pr_warn(FW_BUG "No valid trip found\n");
 515                 return -ENODEV;
 516         }
 517         return 0;
 518 }
 519
 520 static void acpi_thermal_check(void *data)
 521 {
 522         struct acpi_thermal *tz = data;
 523
 524         if (!tz->tz_enabled)
 525                 return;
 526
 527         thermal_zone_device_update(tz->thermal_zone);
 528 }
 529
 530 /* sys I/F for generic thermal sysfs support */
 531
 532 static int thermal_get_temp(struct thermal_zone_device *thermal,
 533                             unsigned long *temp)
 534 {
 535         struct acpi_thermal *tz = thermal->devdata;
 536         int result;
 537
 538         if (!tz)
 539                 return -EINVAL;
 540
 541         result = acpi_thermal_get_temperature(tz);
 542         if (result)
 543                 return result;
 544
 545         *temp = DECI_KELVIN_TO_MILLICELSIUS_WITH_OFFSET(tz->temperature,
 546                                                         tz->kelvin_offset);
 547         return 0;
 548 }
 549
 550 static int thermal_get_mode(struct thermal_zone_device *thermal,
 551                                 enum thermal_device_mode *mode)
 552 {
 553         struct acpi_thermal *tz = thermal->devdata;
 554
 555         if (!tz)
 556                 return -EINVAL;
 557
 558         *mode = tz->tz_enabled ? THERMAL_DEVICE_ENABLED :
 559                 THERMAL_DEVICE_DISABLED;
 560
 561         return 0;
 562 }
 563
 564 static int thermal_set_mode(struct thermal_zone_device *thermal,
 565                                 enum thermal_device_mode mode)
 566 {
 567         struct acpi_thermal *tz = thermal->devdata;
 568         int enable;
 569
 570         if (!tz)
 571                 return -EINVAL;
 572
 573         /*
 574          * enable/disable thermal management from ACPI thermal driver
 575          */
 576         if (mode == THERMAL_DEVICE_ENABLED)
 577                 enable = 1;
 578         else if (mode == THERMAL_DEVICE_DISABLED) {
 579                 enable = 0;
 580                 pr_warn("thermal zone will be disabled\n");
 581         } else
 582                 return -EINVAL;
 583
 584         if (enable != tz->tz_enabled) {
 585                 tz->tz_enabled = enable;
 586                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 587                         "%s kernel ACPI thermal control\n",
 588                         tz->tz_enabled ? "Enable" : "Disable"));
 589                 acpi_thermal_check(tz);
 590         }
 591         return 0;
 592 }
 593
 594 static int thermal_get_trip_type(struct thermal_zone_device *thermal,
 595                                  int trip, enum thermal_trip_type *type)
 596 {
 597         struct acpi_thermal *tz = thermal->devdata;
 598         int i;
 599
 600         if (!tz || trip < 0)
 601                 return -EINVAL;
 602
 603         if (tz->trips.critical.flags.valid) {
 604                 if (!trip) {
 605                         *type = THERMAL_TRIP_CRITICAL;
 606                         return 0;
 607                 }
 608                 trip--;
 609         }
 610
 611         if (tz->trips.hot.flags.valid) {
 612                 if (!trip) {
 613                         *type = THERMAL_TRIP_HOT;
 614                         return 0;
 615                 }
 616                 trip--;
 617         }
 618
 619         if (tz->trips.passive.flags.valid) {
 620                 if (!trip) {
 621                         *type = THERMAL_TRIP_PASSIVE;
 622                         return 0;
 623                 }
 624                 trip--;
 625         }
 626
 627         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE &&
 628                 tz->trips.active[i].flags.valid; i++) {
 629                 if (!trip) {
 630                         *type = THERMAL_TRIP_ACTIVE;
 631                         return 0;
 632                 }
 633                 trip--;
 634         }
 635
 636         return -EINVAL;
 637 }
 638
 639 static int thermal_get_trip_temp(struct thermal_zone_device *thermal,
 640                                  int trip, unsigned long *temp)
 641 {
 642         struct acpi_thermal *tz = thermal->devdata;
 643         int i;
 644
 645         if (!tz || trip < 0)
 646                 return -EINVAL;
 647
 648         if (tz->trips.critical.flags.valid) {
 649                 if (!trip) {
 650                         *temp = DECI_KELVIN_TO_MILLICELSIUS_WITH_OFFSET(
 651                                 tz->trips.critical.temperature,
 652                                 tz->kelvin_offset);
 653                         return 0;
 654                 }
 655                 trip--;
 656         }
 657
 658         if (tz->trips.hot.flags.valid) {
 659                 if (!trip) {
 660                         *temp = DECI_KELVIN_TO_MILLICELSIUS_WITH_OFFSET(
 661                                 tz->trips.hot.temperature,
 662                                 tz->kelvin_offset);
 663                         return 0;
 664                 }
 665                 trip--;
 666         }
 667
 668         if (tz->trips.passive.flags.valid) {
 669                 if (!trip) {
 670                         *temp = DECI_KELVIN_TO_MILLICELSIUS_WITH_OFFSET(
 671                                 tz->trips.passive.temperature,
 672                                 tz->kelvin_offset);
 673                         return 0;
 674                 }
 675                 trip--;
 676         }
 677
 678         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE &&
 679                 tz->trips.active[i].flags.valid; i++) {
 680                 if (!trip) {
 681                         *temp = DECI_KELVIN_TO_MILLICELSIUS_WITH_OFFSET(
 682                                 tz->trips.active[i].temperature,
 683                                 tz->kelvin_offset);
 684                         return 0;
 685                 }
 686                 trip--;
 687         }
 688
 689         return -EINVAL;
 690 }
 691
 692 static int thermal_get_crit_temp(struct thermal_zone_device *thermal,
 693                                 unsigned long *temperature) {
 694         struct acpi_thermal *tz = thermal->devdata;
 695
 696         if (tz->trips.critical.flags.valid) {
 697                 *temperature = DECI_KELVIN_TO_MILLICELSIUS_WITH_OFFSET(
 698                                 tz->trips.critical.temperature,
 699                                 tz->kelvin_offset);
 700                 return 0;
 701         } else
 702                 return -EINVAL;
 703 }
 704
 705 static int thermal_get_trend(struct thermal_zone_device *thermal,
 706                                 int trip, enum thermal_trend *trend)
 707 {
 708         struct acpi_thermal *tz = thermal->devdata;
 709         enum thermal_trip_type type;
 710         int i;
 711
 712         if (thermal_get_trip_type(thermal, trip, &type))
 713                 return -EINVAL;
 714
 715         if (type == THERMAL_TRIP_ACTIVE) {
 716                 unsigned long trip_temp;
 717                 unsigned long temp = DECI_KELVIN_TO_MILLICELSIUS_WITH_OFFSET(
 718                                         tz->temperature, tz->kelvin_offset);
 719                 if (thermal_get_trip_temp(thermal, trip, &trip_temp))
 720                         return -EINVAL;
 721
 722                 if (temp > trip_temp) {
 723                         *trend = THERMAL_TREND_RAISING;
 724                         return 0;
 725                 } else {
 726                         /* Fall back on default trend */
 727                         return -EINVAL;
 728                 }
 729         }
 730
 731         /*
 732          * tz->temperature has already been updated by generic thermal layer,
 733          * before this callback being invoked
 734          */
 735         i = (tz->trips.passive.tc1 * (tz->temperature - tz->last_temperature))
 736                 + (tz->trips.passive.tc2
 737                 * (tz->temperature - tz->trips.passive.temperature));
 738
 739         if (i > 0)
 740                 *trend = THERMAL_TREND_RAISING;
 741         else if (i < 0)
 742                 *trend = THERMAL_TREND_DROPPING;
 743         else
 744                 *trend = THERMAL_TREND_STABLE;
 745         return 0;
 746 }
 747
 748
 749 static int thermal_notify(struct thermal_zone_device *thermal, int trip,
 750                            enum thermal_trip_type trip_type)
 751 {
 752         u8 type = 0;
 753         struct acpi_thermal *tz = thermal->devdata;
 754
 755         if (trip_type == THERMAL_TRIP_CRITICAL)
 756                 type = ACPI_THERMAL_NOTIFY_CRITICAL;
 757         else if (trip_type == THERMAL_TRIP_HOT)
 758                 type = ACPI_THERMAL_NOTIFY_HOT;
 759         else
 760                 return 0;
 761
 762         acpi_bus_generate_netlink_event(tz->device->pnp.device_class,
 763                                         dev_name(&tz->device->dev), type, 1);
 764
 765         if (trip_type == THERMAL_TRIP_CRITICAL && nocrt)
 766                 return 1;
 767
 768         return 0;
 769 }
 770
 771 static int acpi_thermal_cooling_device_cb(struct thermal_zone_device *thermal,
 772                                         struct thermal_cooling_device *cdev,
 773                                         bool bind)
 774 {
 775         struct acpi_device *device = cdev->devdata;
 776         struct acpi_thermal *tz = thermal->devdata;
 777         struct acpi_device *dev;
 778         acpi_status status;
 779         acpi_handle handle;
 780         int i;
 781         int j;
 782         int trip = -1;
 783         int result = 0;
 784
 785         if (tz->trips.critical.flags.valid)
 786                 trip++;
 787
 788         if (tz->trips.hot.flags.valid)
 789                 trip++;
 790
 791         if (tz->trips.passive.flags.valid) {
 792                 trip++;
 793                 for (i = 0; i < tz->trips.passive.devices.count;
 794                     i++) {
 795                         handle = tz->trips.passive.devices.handles[i];
 796                         status = acpi_bus_get_device(handle, &dev);
 797                         if (ACPI_FAILURE(status) || dev != device)
 798                                 continue;
 799                         if (bind)
 800                                 result =
 801                                         thermal_zone_bind_cooling_device
 802                                         (thermal, trip, cdev,
 803                                          THERMAL_NO_LIMIT, THERMAL_NO_LIMIT,
 804                                          THERMAL_WEIGHT_DEFAULT);
 805                         else
 806                                 result =
 807                                         thermal_zone_unbind_cooling_device
 808                                         (thermal, trip, cdev);
 809                         if (result)
 810                                 goto failed;
 811                 }
 812         }
 813
 814         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
 815                 if (!tz->trips.active[i].flags.valid)
 816                         break;
 817                 trip++;
 818                 for (j = 0;
 819                     j < tz->trips.active[i].devices.count;
 820                     j++) {
 821                         handle = tz->trips.active[i].devices.handles[j];
 822                         status = acpi_bus_get_device(handle, &dev);
 823                         if (ACPI_FAILURE(status) || dev != device)
 824                                 continue;
 825                         if (bind)
 826                                 result = thermal_zone_bind_cooling_device
 827                                         (thermal, trip, cdev,
 828                                          THERMAL_NO_LIMIT, THERMAL_NO_LIMIT,
 829                                          THERMAL_WEIGHT_DEFAULT);
 830                         else
 831                                 result = thermal_zone_unbind_cooling_device
 832                                         (thermal, trip, cdev);
 833                         if (result)
 834                                 goto failed;
 835                 }
 836         }
 837
 838         for (i = 0; i < tz->devices.count; i++) {
 839                 handle = tz->devices.handles[i];
 840                 status = acpi_bus_get_device(handle, &dev);
 841                 if (ACPI_SUCCESS(status) && (dev == device)) {
 842                         if (bind)
 843                                 result = thermal_zone_bind_cooling_device
 844                                                 (thermal, THERMAL_TRIPS_NONE,
 845                                                  cdev, THERMAL_NO_LIMIT,
 846                                                  THERMAL_NO_LIMIT,
 847                                                  THERMAL_WEIGHT_DEFAULT);
 848                         else
 849                                 result = thermal_zone_unbind_cooling_device
 850                                                 (thermal, THERMAL_TRIPS_NONE,
 851                                                  cdev);
 852                         if (result)
 853                                 goto failed;
 854                 }
 855         }
 856
 857 failed:
 858         return result;
 859 }
 860
 861 static int
 862 acpi_thermal_bind_cooling_device(struct thermal_zone_device *thermal,
 863                                         struct thermal_cooling_device *cdev)
 864 {
 865         return acpi_thermal_cooling_device_cb(thermal, cdev, true);
 866 }
 867
 868 static int
 869 acpi_thermal_unbind_cooling_device(struct thermal_zone_device *thermal,
 870                                         struct thermal_cooling_device *cdev)
 871 {
 872         return acpi_thermal_cooling_device_cb(thermal, cdev, false);
 873 }
 874
 875 static struct thermal_zone_device_ops acpi_thermal_zone_ops = {
 876         .bind = acpi_thermal_bind_cooling_device,
 877         .unbind = acpi_thermal_unbind_cooling_device,
 878         .get_temp = thermal_get_temp,
 879         .get_mode = thermal_get_mode,
 880         .set_mode = thermal_set_mode,
 881         .get_trip_type = thermal_get_trip_type,
 882         .get_trip_temp = thermal_get_trip_temp,
 883         .get_crit_temp = thermal_get_crit_temp,
 884         .get_trend = thermal_get_trend,
 885         .notify = thermal_notify,
 886 };
 887
 888 static int acpi_thermal_register_thermal_zone(struct acpi_thermal *tz)
 889 {
 890         int trips = 0;
 891         int result;
 892         acpi_status status;
 893         int i;
 894
 895         if (tz->trips.critical.flags.valid)
 896                 trips++;
 897
 898         if (tz->trips.hot.flags.valid)
 899                 trips++;
 900
 901         if (tz->trips.passive.flags.valid)
 902                 trips++;
 903
 904         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE &&
 905                         tz->trips.active[i].flags.valid; i++, trips++);
 906
 907         if (tz->trips.passive.flags.valid)
 908                 tz->thermal_zone =
 909                         thermal_zone_device_register("acpitz", trips, 0, tz,
 910                                                 &acpi_thermal_zone_ops, NULL,
 911                                                      tz->trips.passive.tsp*100,
 912                                                      tz->polling_frequency*100);
 913         else
 914                 tz->thermal_zone =
 915                         thermal_zone_device_register("acpitz", trips, 0, tz,
 916                                                 &acpi_thermal_zone_ops, NULL,
 917                                                 0, tz->polling_frequency*100);
 918         if (IS_ERR(tz->thermal_zone))
 919                 return -ENODEV;
 920
 921         result = sysfs_create_link(&tz->device->dev.kobj,
 922                                    &tz->thermal_zone->device.kobj, "thermal_zone");
 923         if (result)
 924                 return result;
 925
 926         result = sysfs_create_link(&tz->thermal_zone->device.kobj,
 927                                    &tz->device->dev.kobj, "device");
 928         if (result)
 929                 return result;
 930
 931         status =  acpi_bus_attach_private_data(tz->device->handle,
 932                                                tz->thermal_zone);
 933         if (ACPI_FAILURE(status))
 934                 return -ENODEV;
 935
 936         tz->tz_enabled = 1;
 937
 938         dev_info(&tz->device->dev, "registered as thermal_zone%d\n",
 939                  tz->thermal_zone->id);
 940         return 0;
 941 }
 942
 943 static void acpi_thermal_unregister_thermal_zone(struct acpi_thermal *tz)
 944 {
 945         sysfs_remove_link(&tz->device->dev.kobj, "thermal_zone");
 946         sysfs_remove_link(&tz->thermal_zone->device.kobj, "device");
 947         thermal_zone_device_unregister(tz->thermal_zone);
 948         tz->thermal_zone = NULL;
 949         acpi_bus_detach_private_data(tz->device->handle);
 950 }
 951
 952
 953 /* --------------------------------------------------------------------------
 954                                  Driver Interface
 955    -------------------------------------------------------------------------- */
 956
 957 static void acpi_thermal_notify(struct acpi_device *device, u32 event)
 958 {
 959         struct acpi_thermal *tz = acpi_driver_data(device);
 960
 961
 962         if (!tz)
 963                 return;
 964
 965         switch (event) {
 966         case ACPI_THERMAL_NOTIFY_TEMPERATURE:
 967                 acpi_thermal_check(tz);
 968                 break;
 969         case ACPI_THERMAL_NOTIFY_THRESHOLDS:
 970                 acpi_thermal_trips_update(tz, ACPI_TRIPS_REFRESH_THRESHOLDS);
 971                 acpi_thermal_check(tz);
 972                 acpi_bus_generate_netlink_event(device->pnp.device_class,
 973                                                   dev_name(&device->dev), event, 0);
 974                 break;
 975         case ACPI_THERMAL_NOTIFY_DEVICES:
 976                 acpi_thermal_trips_update(tz, ACPI_TRIPS_REFRESH_DEVICES);
 977                 acpi_thermal_check(tz);
 978                 acpi_bus_generate_netlink_event(device->pnp.device_class,
 979                                                   dev_name(&device->dev), event, 0);
 980                 break;
 981         default:
 982                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 983                                   "Unsupported event [0x%x]\n", event));
 984                 break;
 985         }
 986 }
 987
 988 /*
 989  * On some platforms, the AML code has dependency about
 990  * the evaluating order of _TMP and _CRT/_HOT/_PSV/_ACx.
 991  * 1. On HP Pavilion G4-1016tx, _TMP must be invoked after
 992  *    /_CRT/_HOT/_PSV/_ACx, or else system will be power off.
 993  * 2. On HP Compaq 6715b/6715s, the return value of _PSV is 0
 994  *    if _TMP has never been evaluated.
 995  *
 996  * As this dependency is totally transparent to OS, evaluate
 997  * all of them once, in the order of _CRT/_HOT/_PSV/_ACx,
 998  * _TMP, before they are actually used.
 999  */
1000 static void acpi_thermal_aml_dependency_fix(struct acpi_thermal *tz)
1001 {
1002         acpi_handle handle = tz->device->handle;
1003         unsigned long long value;
1004         int i;
1005
1006         acpi_evaluate_integer(handle, "_CRT", NULL, &value);
1007         acpi_evaluate_integer(handle, "_HOT", NULL, &value);
1008         acpi_evaluate_integer(handle, "_PSV", NULL, &value);
1009         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
1010                 char name[5] = { '_', 'A', 'C', ('0' + i), '\0' };
1011                 acpi_status status;
1012
1013                 status = acpi_evaluate_integer(handle, name, NULL, &value);
1014                 if (status == AE_NOT_FOUND)
1015                         break;
1016         }
1017         acpi_evaluate_integer(handle, "_TMP", NULL, &value);
1018 }
1019
1020 static int acpi_thermal_get_info(struct acpi_thermal *tz)
1021 {
1022         int result = 0;
1023
1024
1025         if (!tz)
1026                 return -EINVAL;
1027
1028         acpi_thermal_aml_dependency_fix(tz);
1029
1030         /* Get trip points [_CRT, _PSV, etc.] (required) */
1031         result = acpi_thermal_get_trip_points(tz);
1032         if (result)
1033                 return result;
1034
1035         /* Get temperature [_TMP] (required) */
1036         result = acpi_thermal_get_temperature(tz);
1037         if (result)
1038                 return result;
1039
1040         /* Set the cooling mode [_SCP] to active cooling (default) */
1041         result = acpi_thermal_set_cooling_mode(tz, ACPI_THERMAL_MODE_ACTIVE);
1042         if (!result)
1043                 tz->flags.cooling_mode = 1;
1044
1045         /* Get default polling frequency [_TZP] (optional) */
1046         if (tzp)
1047                 tz->polling_frequency = tzp;
1048         else
1049                 acpi_thermal_get_polling_frequency(tz);
1050
1051         return 0;
1052 }
1053
1054 /*
1055  * The exact offset between Kelvin and degree Celsius is 273.15. However ACPI
1056  * handles temperature values with a single decimal place. As a consequence,
1057  * some implementations use an offset of 273.1 and others use an offset of
1058  * 273.2. Try to find out which one is being used, to present the most
1059  * accurate and visually appealing number.
1060  *
1061  * The heuristic below should work for all ACPI thermal zones which have a
1062  * critical trip point with a value being a multiple of 0.5 degree Celsius.
1063  */
1064 static void acpi_thermal_guess_offset(struct acpi_thermal *tz)
1065 {
1066         if (tz->trips.critical.flags.valid &&
1067             (tz->trips.critical.temperature % 5) == 1)
1068                 tz->kelvin_offset = 2731;
1069         else
1070                 tz->kelvin_offset = 2732;
1071 }
1072
1073 static void acpi_thermal_check_fn(struct work_struct *work)
1074 {
1075         struct acpi_thermal *tz = container_of(work, struct acpi_thermal,
1076                                                thermal_check_work);
1077         acpi_thermal_check(tz);
1078 }
1079
1080 static int acpi_thermal_add(struct acpi_device *device)
1081 {
1082         int result = 0;
1083         struct acpi_thermal *tz = NULL;
1084
1085
1086         if (!device)
1087                 return -EINVAL;
1088
1089         tz = kzalloc(sizeof(struct acpi_thermal), GFP_KERNEL);
1090         if (!tz)
1091                 return -ENOMEM;
1092
1093         tz->device = device;
1094         strcpy(tz->name, device->pnp.bus_id);
1095         strcpy(acpi_device_name(device), ACPI_THERMAL_DEVICE_NAME);
1096         strcpy(acpi_device_class(device), ACPI_THERMAL_CLASS);
1097         device->driver_data = tz;
1098
1099         result = acpi_thermal_get_info(tz);
1100         if (result)
1101                 goto free_memory;
1102
1103         acpi_thermal_guess_offset(tz);
1104
1105         result = acpi_thermal_register_thermal_zone(tz);
1106         if (result)
1107                 goto free_memory;
1108
1109         INIT_WORK(&tz->thermal_check_work, acpi_thermal_check_fn);
1110
1111         pr_info(PREFIX "%s [%s] (%ld C)\n", acpi_device_name(device),
1112                 acpi_device_bid(device), KELVIN_TO_CELSIUS(tz->temperature));
1113         goto end;
1114
1115 free_memory:
1116         kfree(tz);
1117 end:
1118         return result;
1119 }
1120
1121 static int acpi_thermal_remove(struct acpi_device *device)
1122 {
1123         struct acpi_thermal *tz = NULL;
1124
1125         if (!device || !acpi_driver_data(device))
1126                 return -EINVAL;
1127
1128         flush_workqueue(acpi_thermal_pm_queue);
1129         tz = acpi_driver_data(device);
1130
1131         acpi_thermal_unregister_thermal_zone(tz);
1132         kfree(tz);
1133         return 0;
1134 }
1135
1136 #ifdef CONFIG_PM_SLEEP
1137 static int acpi_thermal_suspend(struct device *dev)
1138 {
1139         /* Make sure the previously queued thermal check work has been done */
1140         flush_workqueue(acpi_thermal_pm_queue);
1141         return 0;
1142 }
1143
1144 static int acpi_thermal_resume(struct device *dev)
1145 {
1146         struct acpi_thermal *tz;
1147         int i, j, power_state, result;
1148
1149         if (!dev)
1150                 return -EINVAL;
1151
1152         tz = acpi_driver_data(to_acpi_device(dev));
1153         if (!tz)
1154                 return -EINVAL;
1155
1156         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
1157                 if (!(&tz->trips.active[i]))
1158                         break;
1159                 if (!tz->trips.active[i].flags.valid)
1160                         break;
1161                 tz->trips.active[i].flags.enabled = 1;
1162                 for (j = 0; j < tz->trips.active[i].devices.count; j++) {
1163                         result = acpi_bus_update_power(
1164                                         tz->trips.active[i].devices.handles[j],
1165                                         &power_state);
1166                         if (result || (power_state != ACPI_STATE_D0)) {
1167                                 tz->trips.active[i].flags.enabled = 0;
1168                                 break;
1169                         }
1170                 }
1171                 tz->state.active |= tz->trips.active[i].flags.enabled;
1172         }
1173
1174         queue_work(acpi_thermal_pm_queue, &tz->thermal_check_work);
1175
1176         return AE_OK;
1177 }
1178 #endif
1179
1180 static int thermal_act(const struct dmi_system_id *d) {
1181
1182         if (act == 0) {
1183                 pr_notice(PREFIX "%s detected: "
1184                           "disabling all active thermal trip points\n", d->ident);
1185                 act = -1;
1186         }
1187         return 0;
1188 }
1189 static int thermal_nocrt(const struct dmi_system_id *d) {
1190
1191         pr_notice(PREFIX "%s detected: "
1192                   "disabling all critical thermal trip point actions.\n", d->ident);
1193         nocrt = 1;
1194         return 0;
1195 }
1196 static int thermal_tzp(const struct dmi_system_id *d) {
1197
1198         if (tzp == 0) {
1199                 pr_notice(PREFIX "%s detected: "
1200                           "enabling thermal zone polling\n", d->ident);
1201                 tzp = 300;      /* 300 dS = 30 Seconds */
1202         }
1203         return 0;
1204 }
1205 static int thermal_psv(const struct dmi_system_id *d) {
1206
1207         if (psv == 0) {
1208                 pr_notice(PREFIX "%s detected: "
1209                           "disabling all passive thermal trip points\n", d->ident);
1210                 psv = -1;
1211         }
1212         return 0;
1213 }
1214
1215 static struct dmi_system_id thermal_dmi_table[] __initdata = {
1216         /*
1217          * Award BIOS on this AOpen makes thermal control almost worthless.
1218          * http://bugzilla.kernel.org/show_bug.cgi?id=8842
1219          */
1220         {
1221          .callback = thermal_act,
1222          .ident = "AOpen i915GMm-HFS",
1223          .matches = {
1224                 DMI_MATCH(DMI_BOARD_VENDOR, "AOpen"),
1225                 DMI_MATCH(DMI_BOARD_NAME, "i915GMm-HFS"),
1226                 },
1227         },
1228         {
1229          .callback = thermal_psv,
1230          .ident = "AOpen i915GMm-HFS",
1231          .matches = {
1232                 DMI_MATCH(DMI_BOARD_VENDOR, "AOpen"),
1233                 DMI_MATCH(DMI_BOARD_NAME, "i915GMm-HFS"),
1234                 },
1235         },
1236         {
1237          .callback = thermal_tzp,
1238          .ident = "AOpen i915GMm-HFS",
1239          .matches = {
1240                 DMI_MATCH(DMI_BOARD_VENDOR, "AOpen"),
1241                 DMI_MATCH(DMI_BOARD_NAME, "i915GMm-HFS"),
1242                 },
1243         },
1244         {
1245          .callback = thermal_nocrt,
1246          .ident = "Gigabyte GA-7ZX",
1247          .matches = {
1248                 DMI_MATCH(DMI_BOARD_VENDOR, "Gigabyte Technology Co., Ltd."),
1249                 DMI_MATCH(DMI_BOARD_NAME, "7ZX"),
1250                 },
1251         },
1252         {}
1253 };
1254
1255 static int __init acpi_thermal_init(void)
1256 {
1257         int result = 0;
1258
1259         dmi_check_system(thermal_dmi_table);
1260
1261         if (off) {
1262                 pr_notice(PREFIX "thermal control disabled\n");
1263                 return -ENODEV;
1264         }
1265
1266         acpi_thermal_pm_queue = create_workqueue("acpi_thermal_pm");
1267         if (!acpi_thermal_pm_queue)
1268                 return -ENODEV;
1269
1270         result = acpi_bus_register_driver(&acpi_thermal_driver);
1271         if (result < 0) {
1272                 destroy_workqueue(acpi_thermal_pm_queue);
1273                 return -ENODEV;
1274         }
1275
1276         return 0;
1277 }
1278
1279 static void __exit acpi_thermal_exit(void)
1280 {
1281         acpi_bus_unregister_driver(&acpi_thermal_driver);
1282         destroy_workqueue(acpi_thermal_pm_queue);
1283
1284         return;
1285 }
1286
1287 module_init(acpi_thermal_init);
1288 module_exit(acpi_thermal_exit);