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 <asm/uaccess.h>
  45 #include <linux/thermal.h>
  46 #include <acpi/acpi_bus.h>
  47 #include <acpi/acpi_drivers.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_FILE_STATE         "state"
  54 #define ACPI_THERMAL_FILE_TEMPERATURE   "temperature"
  55 #define ACPI_THERMAL_FILE_TRIP_POINTS   "trip_points"
  56 #define ACPI_THERMAL_FILE_COOLING_MODE  "cooling_mode"
  57 #define ACPI_THERMAL_FILE_POLLING_FREQ  "polling_frequency"
  58 #define ACPI_THERMAL_NOTIFY_TEMPERATURE 0x80
  59 #define ACPI_THERMAL_NOTIFY_THRESHOLDS  0x81
  60 #define ACPI_THERMAL_NOTIFY_DEVICES     0x82
  61 #define ACPI_THERMAL_NOTIFY_CRITICAL    0xF0
  62 #define ACPI_THERMAL_NOTIFY_HOT         0xF1
  63 #define ACPI_THERMAL_MODE_ACTIVE        0x00
  64
  65 #define ACPI_THERMAL_MAX_ACTIVE 10
  66 #define ACPI_THERMAL_MAX_LIMIT_STR_LEN 65
  67
  68 #define _COMPONENT              ACPI_THERMAL_COMPONENT
  69 ACPI_MODULE_NAME("thermal");
  70
  71 MODULE_AUTHOR("Paul Diefenbaugh");
  72 MODULE_DESCRIPTION("ACPI Thermal Zone Driver");
  73 MODULE_LICENSE("GPL");
  74
  75 static int act;
  76 module_param(act, int, 0644);
  77 MODULE_PARM_DESC(act, "Disable or override all lowest active trip points.");
  78
  79 static int crt;
  80 module_param(crt, int, 0644);
  81 MODULE_PARM_DESC(crt, "Disable or lower all critical trip points.");
  82
  83 static int tzp;
  84 module_param(tzp, int, 0444);
  85 MODULE_PARM_DESC(tzp, "Thermal zone polling frequency, in 1/10 seconds.");
  86
  87 static int nocrt;
  88 module_param(nocrt, int, 0);
  89 MODULE_PARM_DESC(nocrt, "Set to take no action upon ACPI thermal zone critical trips points.");
  90
  91 static int off;
  92 module_param(off, int, 0);
  93 MODULE_PARM_DESC(off, "Set to disable ACPI thermal support.");
  94
  95 static int psv;
  96 module_param(psv, int, 0644);
  97 MODULE_PARM_DESC(psv, "Disable or override all passive trip points.");
  98
  99 static int acpi_thermal_add(struct acpi_device *device);
 100 static int acpi_thermal_remove(struct acpi_device *device);
 101 static void acpi_thermal_notify(struct acpi_device *device, u32 event);
 102
 103 static const struct acpi_device_id  thermal_device_ids[] = {
 104         {ACPI_THERMAL_HID, 0},
 105         {"", 0},
 106 };
 107 MODULE_DEVICE_TABLE(acpi, thermal_device_ids);
 108
 109 #ifdef CONFIG_PM_SLEEP
 110 static int acpi_thermal_resume(struct device *dev);
 111 #endif
 112 static SIMPLE_DEV_PM_OPS(acpi_thermal_pm, NULL, acpi_thermal_resume);
 113
 114 static struct acpi_driver acpi_thermal_driver = {
 115         .name = "thermal",
 116         .class = ACPI_THERMAL_CLASS,
 117         .ids = thermal_device_ids,
 118         .ops = {
 119                 .add = acpi_thermal_add,
 120                 .remove = acpi_thermal_remove,
 121                 .notify = acpi_thermal_notify,
 122                 },
 123         .drv.pm = &acpi_thermal_pm,
 124 };
 125
 126 struct acpi_thermal_state {
 127         u8 critical:1;
 128         u8 hot:1;
 129         u8 passive:1;
 130         u8 active:1;
 131         u8 reserved:4;
 132         int active_index;
 133 };
 134
 135 struct acpi_thermal_state_flags {
 136         u8 valid:1;
 137         u8 enabled:1;
 138         u8 reserved:6;
 139 };
 140
 141 struct acpi_thermal_critical {
 142         struct acpi_thermal_state_flags flags;
 143         unsigned long temperature;
 144 };
 145
 146 struct acpi_thermal_hot {
 147         struct acpi_thermal_state_flags flags;
 148         unsigned long temperature;
 149 };
 150
 151 struct acpi_thermal_passive {
 152         struct acpi_thermal_state_flags flags;
 153         unsigned long temperature;
 154         unsigned long tc1;
 155         unsigned long tc2;
 156         unsigned long tsp;
 157         struct acpi_handle_list devices;
 158 };
 159
 160 struct acpi_thermal_active {
 161         struct acpi_thermal_state_flags flags;
 162         unsigned long temperature;
 163         struct acpi_handle_list devices;
 164 };
 165
 166 struct acpi_thermal_trips {
 167         struct acpi_thermal_critical critical;
 168         struct acpi_thermal_hot hot;
 169         struct acpi_thermal_passive passive;
 170         struct acpi_thermal_active active[ACPI_THERMAL_MAX_ACTIVE];
 171 };
 172
 173 struct acpi_thermal_flags {
 174         u8 cooling_mode:1;      /* _SCP */
 175         u8 devices:1;           /* _TZD */
 176         u8 reserved:6;
 177 };
 178
 179 struct acpi_thermal {
 180         struct acpi_device * device;
 181         acpi_bus_id name;
 182         unsigned long temperature;
 183         unsigned long last_temperature;
 184         unsigned long polling_frequency;
 185         volatile u8 zombie;
 186         struct acpi_thermal_flags flags;
 187         struct acpi_thermal_state state;
 188         struct acpi_thermal_trips trips;
 189         struct acpi_handle_list devices;
 190         struct thermal_zone_device *thermal_zone;
 191         int tz_enabled;
 192         int kelvin_offset;
 193         struct mutex lock;
 194 };
 195
 196 /* --------------------------------------------------------------------------
 197                              Thermal Zone Management
 198    -------------------------------------------------------------------------- */
 199
 200 static int acpi_thermal_get_temperature(struct acpi_thermal *tz)
 201 {
 202         acpi_status status = AE_OK;
 203         unsigned long long tmp;
 204
 205         if (!tz)
 206                 return -EINVAL;
 207
 208         tz->last_temperature = tz->temperature;
 209
 210         status = acpi_evaluate_integer(tz->device->handle, "_TMP", NULL, &tmp);
 211         if (ACPI_FAILURE(status))
 212                 return -ENODEV;
 213
 214         tz->temperature = tmp;
 215         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Temperature is %lu dK\n",
 216                           tz->temperature));
 217
 218         return 0;
 219 }
 220
 221 static int acpi_thermal_get_polling_frequency(struct acpi_thermal *tz)
 222 {
 223         acpi_status status = AE_OK;
 224         unsigned long long tmp;
 225
 226         if (!tz)
 227                 return -EINVAL;
 228
 229         status = acpi_evaluate_integer(tz->device->handle, "_TZP", NULL, &tmp);
 230         if (ACPI_FAILURE(status))
 231                 return -ENODEV;
 232
 233         tz->polling_frequency = tmp;
 234         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Polling frequency is %lu dS\n",
 235                           tz->polling_frequency));
 236
 237         return 0;
 238 }
 239
 240 static int acpi_thermal_set_cooling_mode(struct acpi_thermal *tz, int mode)
 241 {
 242         acpi_status status = AE_OK;
 243         union acpi_object arg0 = { ACPI_TYPE_INTEGER };
 244         struct acpi_object_list arg_list = { 1, &arg0 };
 245         acpi_handle handle = NULL;
 246
 247
 248         if (!tz)
 249                 return -EINVAL;
 250
 251         status = acpi_get_handle(tz->device->handle, "_SCP", &handle);
 252         if (ACPI_FAILURE(status)) {
 253                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "_SCP not present\n"));
 254                 return -ENODEV;
 255         }
 256
 257         arg0.integer.value = mode;
 258
 259         status = acpi_evaluate_object(handle, NULL, &arg_list, NULL);
 260         if (ACPI_FAILURE(status))
 261                 return -ENODEV;
 262
 263         return 0;
 264 }
 265
 266 #define ACPI_TRIPS_CRITICAL     0x01
 267 #define ACPI_TRIPS_HOT          0x02
 268 #define ACPI_TRIPS_PASSIVE      0x04
 269 #define ACPI_TRIPS_ACTIVE       0x08
 270 #define ACPI_TRIPS_DEVICES      0x10
 271
 272 #define ACPI_TRIPS_REFRESH_THRESHOLDS   (ACPI_TRIPS_PASSIVE | ACPI_TRIPS_ACTIVE)
 273 #define ACPI_TRIPS_REFRESH_DEVICES      ACPI_TRIPS_DEVICES
 274
 275 #define ACPI_TRIPS_INIT      (ACPI_TRIPS_CRITICAL | ACPI_TRIPS_HOT |    \
 276                               ACPI_TRIPS_PASSIVE | ACPI_TRIPS_ACTIVE |  \
 277                               ACPI_TRIPS_DEVICES)
 278
 279 /*
 280  * This exception is thrown out in two cases:
 281  * 1.An invalid trip point becomes invalid or a valid trip point becomes invalid
 282  *   when re-evaluating the AML code.
 283  * 2.TODO: Devices listed in _PSL, _ALx, _TZD may change.
 284  *   We need to re-bind the cooling devices of a thermal zone when this occurs.
 285  */
 286 #define ACPI_THERMAL_TRIPS_EXCEPTION(flags, str)        \
 287 do {    \
 288         if (flags != ACPI_TRIPS_INIT)   \
 289                 ACPI_EXCEPTION((AE_INFO, AE_ERROR,      \
 290                 "ACPI thermal trip point %s changed\n"  \
 291                 "Please send acpidump to linux-acpi@vger.kernel.org", str)); \
 292 } while (0)
 293
 294 static int acpi_thermal_trips_update(struct acpi_thermal *tz, int flag)
 295 {
 296         acpi_status status = AE_OK;
 297         unsigned long long tmp;
 298         struct acpi_handle_list devices;
 299         int valid = 0;
 300         int i;
 301
 302         /* Critical Shutdown */
 303         if (flag & ACPI_TRIPS_CRITICAL) {
 304                 status = acpi_evaluate_integer(tz->device->handle,
 305                                 "_CRT", NULL, &tmp);
 306                 tz->trips.critical.temperature = tmp;
 307                 /*
 308                  * Treat freezing temperatures as invalid as well; some
 309                  * BIOSes return really low values and cause reboots at startup.
 310                  * Below zero (Celsius) values clearly aren't right for sure..
 311                  * ... so lets discard those as invalid.
 312                  */
 313                 if (ACPI_FAILURE(status)) {
 314                         tz->trips.critical.flags.valid = 0;
 315                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 316                                           "No critical threshold\n"));
 317                 } else if (tmp <= 2732) {
 318                         printk(KERN_WARNING FW_BUG "Invalid critical threshold "
 319                                "(%llu)\n", tmp);
 320                         tz->trips.critical.flags.valid = 0;
 321                 } else {
 322                         tz->trips.critical.flags.valid = 1;
 323                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 324                                           "Found critical threshold [%lu]\n",
 325                                           tz->trips.critical.temperature));
 326                 }
 327                 if (tz->trips.critical.flags.valid == 1) {
 328                         if (crt == -1) {
 329                                 tz->trips.critical.flags.valid = 0;
 330                         } else if (crt > 0) {
 331                                 unsigned long crt_k = CELSIUS_TO_KELVIN(crt);
 332                                 /*
 333                                  * Allow override critical threshold
 334                                  */
 335                                 if (crt_k > tz->trips.critical.temperature)
 336                                         printk(KERN_WARNING PREFIX
 337                                                 "Critical threshold %d C\n", crt);
 338                                 tz->trips.critical.temperature = crt_k;
 339                         }
 340                 }
 341         }
 342
 343         /* Critical Sleep (optional) */
 344         if (flag & ACPI_TRIPS_HOT) {
 345                 status = acpi_evaluate_integer(tz->device->handle,
 346                                 "_HOT", NULL, &tmp);
 347                 if (ACPI_FAILURE(status)) {
 348                         tz->trips.hot.flags.valid = 0;
 349                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 350                                         "No hot threshold\n"));
 351                 } else {
 352                         tz->trips.hot.temperature = tmp;
 353                         tz->trips.hot.flags.valid = 1;
 354                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 355                                         "Found hot threshold [%lu]\n",
 356                                         tz->trips.critical.temperature));
 357                 }
 358         }
 359
 360         /* Passive (optional) */
 361         if (((flag & ACPI_TRIPS_PASSIVE) && tz->trips.passive.flags.valid) ||
 362                 (flag == ACPI_TRIPS_INIT)) {
 363                 valid = tz->trips.passive.flags.valid;
 364                 if (psv == -1) {
 365                         status = AE_SUPPORT;
 366                 } else if (psv > 0) {
 367                         tmp = CELSIUS_TO_KELVIN(psv);
 368                         status = AE_OK;
 369                 } else {
 370                         status = acpi_evaluate_integer(tz->device->handle,
 371                                 "_PSV", NULL, &tmp);
 372                 }
 373
 374                 if (ACPI_FAILURE(status))
 375                         tz->trips.passive.flags.valid = 0;
 376                 else {
 377                         tz->trips.passive.temperature = tmp;
 378                         tz->trips.passive.flags.valid = 1;
 379                         if (flag == ACPI_TRIPS_INIT) {
 380                                 status = acpi_evaluate_integer(
 381                                                 tz->device->handle, "_TC1",
 382                                                 NULL, &tmp);
 383                                 if (ACPI_FAILURE(status))
 384                                         tz->trips.passive.flags.valid = 0;
 385                                 else
 386                                         tz->trips.passive.tc1 = tmp;
 387                                 status = acpi_evaluate_integer(
 388                                                 tz->device->handle, "_TC2",
 389                                                 NULL, &tmp);
 390                                 if (ACPI_FAILURE(status))
 391                                         tz->trips.passive.flags.valid = 0;
 392                                 else
 393                                         tz->trips.passive.tc2 = tmp;
 394                                 status = acpi_evaluate_integer(
 395                                                 tz->device->handle, "_TSP",
 396                                                 NULL, &tmp);
 397                                 if (ACPI_FAILURE(status))
 398                                         tz->trips.passive.flags.valid = 0;
 399                                 else
 400                                         tz->trips.passive.tsp = tmp;
 401                         }
 402                 }
 403         }
 404         if ((flag & ACPI_TRIPS_DEVICES) && tz->trips.passive.flags.valid) {
 405                 memset(&devices, 0, sizeof(struct acpi_handle_list));
 406                 status = acpi_evaluate_reference(tz->device->handle, "_PSL",
 407                                                         NULL, &devices);
 408                 if (ACPI_FAILURE(status)) {
 409                         printk(KERN_WARNING PREFIX
 410                                 "Invalid passive threshold\n");
 411                         tz->trips.passive.flags.valid = 0;
 412                 }
 413                 else
 414                         tz->trips.passive.flags.valid = 1;
 415
 416                 if (memcmp(&tz->trips.passive.devices, &devices,
 417                                 sizeof(struct acpi_handle_list))) {
 418                         memcpy(&tz->trips.passive.devices, &devices,
 419                                 sizeof(struct acpi_handle_list));
 420                         ACPI_THERMAL_TRIPS_EXCEPTION(flag, "device");
 421                 }
 422         }
 423         if ((flag & ACPI_TRIPS_PASSIVE) || (flag & ACPI_TRIPS_DEVICES)) {
 424                 if (valid != tz->trips.passive.flags.valid)
 425                                 ACPI_THERMAL_TRIPS_EXCEPTION(flag, "state");
 426         }
 427
 428         /* Active (optional) */
 429         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
 430                 char name[5] = { '_', 'A', 'C', ('0' + i), '\0' };
 431                 valid = tz->trips.active[i].flags.valid;
 432
 433                 if (act == -1)
 434                         break; /* disable all active trip points */
 435
 436                 if ((flag == ACPI_TRIPS_INIT) || ((flag & ACPI_TRIPS_ACTIVE) &&
 437                         tz->trips.active[i].flags.valid)) {
 438                         status = acpi_evaluate_integer(tz->device->handle,
 439                                                         name, NULL, &tmp);
 440                         if (ACPI_FAILURE(status)) {
 441                                 tz->trips.active[i].flags.valid = 0;
 442                                 if (i == 0)
 443                                         break;
 444                                 if (act <= 0)
 445                                         break;
 446                                 if (i == 1)
 447                                         tz->trips.active[0].temperature =
 448                                                 CELSIUS_TO_KELVIN(act);
 449                                 else
 450                                         /*
 451                                          * Don't allow override higher than
 452                                          * the next higher trip point
 453                                          */
 454                                         tz->trips.active[i - 1].temperature =
 455                                                 (tz->trips.active[i - 2].temperature <
 456                                                 CELSIUS_TO_KELVIN(act) ?
 457                                                 tz->trips.active[i - 2].temperature :
 458                                                 CELSIUS_TO_KELVIN(act));
 459                                 break;
 460                         } else {
 461                                 tz->trips.active[i].temperature = tmp;
 462                                 tz->trips.active[i].flags.valid = 1;
 463                         }
 464                 }
 465
 466                 name[2] = 'L';
 467                 if ((flag & ACPI_TRIPS_DEVICES) && tz->trips.active[i].flags.valid ) {
 468                         memset(&devices, 0, sizeof(struct acpi_handle_list));
 469                         status = acpi_evaluate_reference(tz->device->handle,
 470                                                 name, NULL, &devices);
 471                         if (ACPI_FAILURE(status)) {
 472                                 printk(KERN_WARNING PREFIX
 473                                         "Invalid active%d threshold\n", i);
 474                                 tz->trips.active[i].flags.valid = 0;
 475                         }
 476                         else
 477                                 tz->trips.active[i].flags.valid = 1;
 478
 479                         if (memcmp(&tz->trips.active[i].devices, &devices,
 480                                         sizeof(struct acpi_handle_list))) {
 481                                 memcpy(&tz->trips.active[i].devices, &devices,
 482                                         sizeof(struct acpi_handle_list));
 483                                 ACPI_THERMAL_TRIPS_EXCEPTION(flag, "device");
 484                         }
 485                 }
 486                 if ((flag & ACPI_TRIPS_ACTIVE) || (flag & ACPI_TRIPS_DEVICES))
 487                         if (valid != tz->trips.active[i].flags.valid)
 488                                 ACPI_THERMAL_TRIPS_EXCEPTION(flag, "state");
 489
 490                 if (!tz->trips.active[i].flags.valid)
 491                         break;
 492         }
 493
 494         if (flag & ACPI_TRIPS_DEVICES) {
 495                 memset(&devices, 0, sizeof(struct acpi_handle_list));
 496                 status = acpi_evaluate_reference(tz->device->handle, "_TZD",
 497                                                 NULL, &devices);
 498                 if (memcmp(&tz->devices, &devices,
 499                                 sizeof(struct acpi_handle_list))) {
 500                         memcpy(&tz->devices, &devices,
 501                                 sizeof(struct acpi_handle_list));
 502                         ACPI_THERMAL_TRIPS_EXCEPTION(flag, "device");
 503                 }
 504         }
 505
 506         return 0;
 507 }
 508
 509 static int acpi_thermal_get_trip_points(struct acpi_thermal *tz)
 510 {
 511         int i, valid, ret = acpi_thermal_trips_update(tz, ACPI_TRIPS_INIT);
 512
 513         if (ret)
 514                 return ret;
 515
 516         valid = tz->trips.critical.flags.valid |
 517                 tz->trips.hot.flags.valid |
 518                 tz->trips.passive.flags.valid;
 519
 520         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++)
 521                 valid |= tz->trips.active[i].flags.valid;
 522
 523         if (!valid) {
 524                 printk(KERN_WARNING FW_BUG "No valid trip found\n");
 525                 return -ENODEV;
 526         }
 527         return 0;
 528 }
 529
 530 static void acpi_thermal_check(void *data)
 531 {
 532         struct acpi_thermal *tz = data;
 533
 534         if (!tz->tz_enabled) {
 535                 pr_warn("thermal zone is disabled \n");
 536                 return;
 537         }
 538         thermal_zone_device_update(tz->thermal_zone);
 539 }
 540
 541 /* sys I/F for generic thermal sysfs support */
 542 #define KELVIN_TO_MILLICELSIUS(t, off) (((t) - (off)) * 100)
 543
 544 static int thermal_get_temp(struct thermal_zone_device *thermal,
 545                             unsigned long *temp)
 546 {
 547         struct acpi_thermal *tz = thermal->devdata;
 548         int result;
 549
 550         if (!tz)
 551                 return -EINVAL;
 552
 553         result = acpi_thermal_get_temperature(tz);
 554         if (result)
 555                 return result;
 556
 557         *temp = KELVIN_TO_MILLICELSIUS(tz->temperature, tz->kelvin_offset);
 558         return 0;
 559 }
 560
 561 static int thermal_get_mode(struct thermal_zone_device *thermal,
 562                                 enum thermal_device_mode *mode)
 563 {
 564         struct acpi_thermal *tz = thermal->devdata;
 565
 566         if (!tz)
 567                 return -EINVAL;
 568
 569         *mode = tz->tz_enabled ? THERMAL_DEVICE_ENABLED :
 570                 THERMAL_DEVICE_DISABLED;
 571
 572         return 0;
 573 }
 574
 575 static int thermal_set_mode(struct thermal_zone_device *thermal,
 576                                 enum thermal_device_mode mode)
 577 {
 578         struct acpi_thermal *tz = thermal->devdata;
 579         int enable;
 580
 581         if (!tz)
 582                 return -EINVAL;
 583
 584         /*
 585          * enable/disable thermal management from ACPI thermal driver
 586          */
 587         if (mode == THERMAL_DEVICE_ENABLED)
 588                 enable = 1;
 589         else if (mode == THERMAL_DEVICE_DISABLED)
 590                 enable = 0;
 591         else
 592                 return -EINVAL;
 593
 594         if (enable != tz->tz_enabled) {
 595                 tz->tz_enabled = enable;
 596                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 597                         "%s kernel ACPI thermal control\n",
 598                         tz->tz_enabled ? "Enable" : "Disable"));
 599                 acpi_thermal_check(tz);
 600         }
 601         return 0;
 602 }
 603
 604 static int thermal_get_trip_type(struct thermal_zone_device *thermal,
 605                                  int trip, enum thermal_trip_type *type)
 606 {
 607         struct acpi_thermal *tz = thermal->devdata;
 608         int i;
 609
 610         if (!tz || trip < 0)
 611                 return -EINVAL;
 612
 613         if (tz->trips.critical.flags.valid) {
 614                 if (!trip) {
 615                         *type = THERMAL_TRIP_CRITICAL;
 616                         return 0;
 617                 }
 618                 trip--;
 619         }
 620
 621         if (tz->trips.hot.flags.valid) {
 622                 if (!trip) {
 623                         *type = THERMAL_TRIP_HOT;
 624                         return 0;
 625                 }
 626                 trip--;
 627         }
 628
 629         if (tz->trips.passive.flags.valid) {
 630                 if (!trip) {
 631                         *type = THERMAL_TRIP_PASSIVE;
 632                         return 0;
 633                 }
 634                 trip--;
 635         }
 636
 637         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE &&
 638                 tz->trips.active[i].flags.valid; i++) {
 639                 if (!trip) {
 640                         *type = THERMAL_TRIP_ACTIVE;
 641                         return 0;
 642                 }
 643                 trip--;
 644         }
 645
 646         return -EINVAL;
 647 }
 648
 649 static int thermal_get_trip_temp(struct thermal_zone_device *thermal,
 650                                  int trip, unsigned long *temp)
 651 {
 652         struct acpi_thermal *tz = thermal->devdata;
 653         int i;
 654
 655         if (!tz || trip < 0)
 656                 return -EINVAL;
 657
 658         if (tz->trips.critical.flags.valid) {
 659                 if (!trip) {
 660                         *temp = KELVIN_TO_MILLICELSIUS(
 661                                 tz->trips.critical.temperature,
 662                                 tz->kelvin_offset);
 663                         return 0;
 664                 }
 665                 trip--;
 666         }
 667
 668         if (tz->trips.hot.flags.valid) {
 669                 if (!trip) {
 670                         *temp = KELVIN_TO_MILLICELSIUS(
 671                                 tz->trips.hot.temperature,
 672                                 tz->kelvin_offset);
 673                         return 0;
 674                 }
 675                 trip--;
 676         }
 677
 678         if (tz->trips.passive.flags.valid) {
 679                 if (!trip) {
 680                         *temp = KELVIN_TO_MILLICELSIUS(
 681                                 tz->trips.passive.temperature,
 682                                 tz->kelvin_offset);
 683                         return 0;
 684                 }
 685                 trip--;
 686         }
 687
 688         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE &&
 689                 tz->trips.active[i].flags.valid; i++) {
 690                 if (!trip) {
 691                         *temp = KELVIN_TO_MILLICELSIUS(
 692                                 tz->trips.active[i].temperature,
 693                                 tz->kelvin_offset);
 694                         return 0;
 695                 }
 696                 trip--;
 697         }
 698
 699         return -EINVAL;
 700 }
 701
 702 static int thermal_get_crit_temp(struct thermal_zone_device *thermal,
 703                                 unsigned long *temperature) {
 704         struct acpi_thermal *tz = thermal->devdata;
 705
 706         if (tz->trips.critical.flags.valid) {
 707                 *temperature = KELVIN_TO_MILLICELSIUS(
 708                                 tz->trips.critical.temperature,
 709                                 tz->kelvin_offset);
 710                 return 0;
 711         } else
 712                 return -EINVAL;
 713 }
 714
 715 static int thermal_get_trend(struct thermal_zone_device *thermal,
 716                                 int trip, enum thermal_trend *trend)
 717 {
 718         struct acpi_thermal *tz = thermal->devdata;
 719         enum thermal_trip_type type;
 720         int i;
 721
 722         if (thermal_get_trip_type(thermal, trip, &type))
 723                 return -EINVAL;
 724
 725         if (type == THERMAL_TRIP_ACTIVE) {
 726                 unsigned long trip_temp;
 727                 unsigned long temp = KELVIN_TO_MILLICELSIUS(tz->temperature,
 728                                                         tz->kelvin_offset);
 729                 if (thermal_get_trip_temp(thermal, trip, &trip_temp))
 730                         return -EINVAL;
 731
 732                 if (temp > trip_temp) {
 733                         *trend = THERMAL_TREND_RAISING;
 734                         return 0;
 735                 } else {
 736                         /* Fall back on default trend */
 737                         return -EINVAL;
 738                 }
 739         }
 740
 741         /*
 742          * tz->temperature has already been updated by generic thermal layer,
 743          * before this callback being invoked
 744          */
 745         i = (tz->trips.passive.tc1 * (tz->temperature - tz->last_temperature))
 746                 + (tz->trips.passive.tc2
 747                 * (tz->temperature - tz->trips.passive.temperature));
 748
 749         if (i > 0)
 750                 *trend = THERMAL_TREND_RAISING;
 751         else if (i < 0)
 752                 *trend = THERMAL_TREND_DROPPING;
 753         else
 754                 *trend = THERMAL_TREND_STABLE;
 755         return 0;
 756 }
 757
 758
 759 static int thermal_notify(struct thermal_zone_device *thermal, int trip,
 760                            enum thermal_trip_type trip_type)
 761 {
 762         u8 type = 0;
 763         struct acpi_thermal *tz = thermal->devdata;
 764
 765         if (trip_type == THERMAL_TRIP_CRITICAL)
 766                 type = ACPI_THERMAL_NOTIFY_CRITICAL;
 767         else if (trip_type == THERMAL_TRIP_HOT)
 768                 type = ACPI_THERMAL_NOTIFY_HOT;
 769         else
 770                 return 0;
 771
 772         acpi_bus_generate_proc_event(tz->device, type, 1);
 773         acpi_bus_generate_netlink_event(tz->device->pnp.device_class,
 774                                         dev_name(&tz->device->dev), type, 1);
 775
 776         if (trip_type == THERMAL_TRIP_CRITICAL && nocrt)
 777                 return 1;
 778
 779         return 0;
 780 }
 781
 782 static int acpi_thermal_cooling_device_cb(struct thermal_zone_device *thermal,
 783                                         struct thermal_cooling_device *cdev,
 784                                         bool bind)
 785 {
 786         struct acpi_device *device = cdev->devdata;
 787         struct acpi_thermal *tz = thermal->devdata;
 788         struct acpi_device *dev;
 789         acpi_status status;
 790         acpi_handle handle;
 791         int i;
 792         int j;
 793         int trip = -1;
 794         int result = 0;
 795
 796         if (tz->trips.critical.flags.valid)
 797                 trip++;
 798
 799         if (tz->trips.hot.flags.valid)
 800                 trip++;
 801
 802         if (tz->trips.passive.flags.valid) {
 803                 trip++;
 804                 for (i = 0; i < tz->trips.passive.devices.count;
 805                     i++) {
 806                         handle = tz->trips.passive.devices.handles[i];
 807                         status = acpi_bus_get_device(handle, &dev);
 808                         if (ACPI_FAILURE(status) || dev != device)
 809                                 continue;
 810                         if (bind)
 811                                 result =
 812                                         thermal_zone_bind_cooling_device
 813                                         (thermal, trip, cdev,
 814                                          THERMAL_NO_LIMIT, THERMAL_NO_LIMIT);
 815                         else
 816                                 result =
 817                                         thermal_zone_unbind_cooling_device
 818                                         (thermal, trip, cdev);
 819                         if (result)
 820                                 goto failed;
 821                 }
 822         }
 823
 824         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
 825                 if (!tz->trips.active[i].flags.valid)
 826                         break;
 827                 trip++;
 828                 for (j = 0;
 829                     j < tz->trips.active[i].devices.count;
 830                     j++) {
 831                         handle = tz->trips.active[i].devices.handles[j];
 832                         status = acpi_bus_get_device(handle, &dev);
 833                         if (ACPI_FAILURE(status) || dev != device)
 834                                 continue;
 835                         if (bind)
 836                                 result = thermal_zone_bind_cooling_device
 837                                         (thermal, trip, cdev,
 838                                          THERMAL_NO_LIMIT, THERMAL_NO_LIMIT);
 839                         else
 840                                 result = thermal_zone_unbind_cooling_device
 841                                         (thermal, trip, cdev);
 842                         if (result)
 843                                 goto failed;
 844                 }
 845         }
 846
 847         for (i = 0; i < tz->devices.count; i++) {
 848                 handle = tz->devices.handles[i];
 849                 status = acpi_bus_get_device(handle, &dev);
 850                 if (ACPI_SUCCESS(status) && (dev == device)) {
 851                         if (bind)
 852                                 result = thermal_zone_bind_cooling_device
 853                                                 (thermal, -1, cdev,
 854                                                  THERMAL_NO_LIMIT,
 855                                                  THERMAL_NO_LIMIT);
 856                         else
 857                                 result = thermal_zone_unbind_cooling_device
 858                                                 (thermal, -1, cdev);
 859                         if (result)
 860                                 goto failed;
 861                 }
 862         }
 863
 864 failed:
 865         return result;
 866 }
 867
 868 static int
 869 acpi_thermal_bind_cooling_device(struct thermal_zone_device *thermal,
 870                                         struct thermal_cooling_device *cdev)
 871 {
 872         return acpi_thermal_cooling_device_cb(thermal, cdev, true);
 873 }
 874
 875 static int
 876 acpi_thermal_unbind_cooling_device(struct thermal_zone_device *thermal,
 877                                         struct thermal_cooling_device *cdev)
 878 {
 879         return acpi_thermal_cooling_device_cb(thermal, cdev, false);
 880 }
 881
 882 static const struct thermal_zone_device_ops acpi_thermal_zone_ops = {
 883         .bind = acpi_thermal_bind_cooling_device,
 884         .unbind = acpi_thermal_unbind_cooling_device,
 885         .get_temp = thermal_get_temp,
 886         .get_mode = thermal_get_mode,
 887         .set_mode = thermal_set_mode,
 888         .get_trip_type = thermal_get_trip_type,
 889         .get_trip_temp = thermal_get_trip_temp,
 890         .get_crit_temp = thermal_get_crit_temp,
 891         .get_trend = thermal_get_trend,
 892         .notify = thermal_notify,
 893 };
 894
 895 static int acpi_thermal_register_thermal_zone(struct acpi_thermal *tz)
 896 {
 897         int trips = 0;
 898         int result;
 899         acpi_status status;
 900         int i;
 901
 902         if (tz->trips.critical.flags.valid)
 903                 trips++;
 904
 905         if (tz->trips.hot.flags.valid)
 906                 trips++;
 907
 908         if (tz->trips.passive.flags.valid)
 909                 trips++;
 910
 911         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE &&
 912                         tz->trips.active[i].flags.valid; i++, trips++);
 913
 914         if (tz->trips.passive.flags.valid)
 915                 tz->thermal_zone =
 916                         thermal_zone_device_register("acpitz", trips, 0, tz,
 917                                                 &acpi_thermal_zone_ops, NULL,
 918                                                      tz->trips.passive.tsp*100,
 919                                                      tz->polling_frequency*100);
 920         else
 921                 tz->thermal_zone =
 922                         thermal_zone_device_register("acpitz", trips, 0, tz,
 923                                                 &acpi_thermal_zone_ops, NULL,
 924                                                 0, tz->polling_frequency*100);
 925         if (IS_ERR(tz->thermal_zone))
 926                 return -ENODEV;
 927
 928         result = sysfs_create_link(&tz->device->dev.kobj,
 929                                    &tz->thermal_zone->device.kobj, "thermal_zone");
 930         if (result)
 931                 return result;
 932
 933         result = sysfs_create_link(&tz->thermal_zone->device.kobj,
 934                                    &tz->device->dev.kobj, "device");
 935         if (result)
 936                 return result;
 937
 938         status = acpi_attach_data(tz->device->handle,
 939                                   acpi_bus_private_data_handler,
 940                                   tz->thermal_zone);
 941         if (ACPI_FAILURE(status)) {
 942                 printk(KERN_ERR PREFIX
 943                                 "Error attaching device data\n");
 944                 return -ENODEV;
 945         }
 946
 947         tz->tz_enabled = 1;
 948
 949         dev_info(&tz->device->dev, "registered as thermal_zone%d\n",
 950                  tz->thermal_zone->id);
 951         return 0;
 952 }
 953
 954 static void acpi_thermal_unregister_thermal_zone(struct acpi_thermal *tz)
 955 {
 956         sysfs_remove_link(&tz->device->dev.kobj, "thermal_zone");
 957         sysfs_remove_link(&tz->thermal_zone->device.kobj, "device");
 958         thermal_zone_device_unregister(tz->thermal_zone);
 959         tz->thermal_zone = NULL;
 960         acpi_detach_data(tz->device->handle, acpi_bus_private_data_handler);
 961 }
 962
 963
 964 /* --------------------------------------------------------------------------
 965                                  Driver Interface
 966    -------------------------------------------------------------------------- */
 967
 968 static void acpi_thermal_notify(struct acpi_device *device, u32 event)
 969 {
 970         struct acpi_thermal *tz = acpi_driver_data(device);
 971
 972
 973         if (!tz)
 974                 return;
 975
 976         switch (event) {
 977         case ACPI_THERMAL_NOTIFY_TEMPERATURE:
 978                 acpi_thermal_check(tz);
 979                 break;
 980         case ACPI_THERMAL_NOTIFY_THRESHOLDS:
 981                 acpi_thermal_trips_update(tz, ACPI_TRIPS_REFRESH_THRESHOLDS);
 982                 acpi_thermal_check(tz);
 983                 acpi_bus_generate_proc_event(device, event, 0);
 984                 acpi_bus_generate_netlink_event(device->pnp.device_class,
 985                                                   dev_name(&device->dev), event, 0);
 986                 break;
 987         case ACPI_THERMAL_NOTIFY_DEVICES:
 988                 acpi_thermal_trips_update(tz, ACPI_TRIPS_REFRESH_DEVICES);
 989                 acpi_thermal_check(tz);
 990                 acpi_bus_generate_proc_event(device, event, 0);
 991                 acpi_bus_generate_netlink_event(device->pnp.device_class,
 992                                                   dev_name(&device->dev), event, 0);
 993                 break;
 994         default:
 995                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 996                                   "Unsupported event [0x%x]\n", event));
 997                 break;
 998         }
 999 }
1000
1001 /*
1002  * On some platforms, the AML code has dependency about
1003  * the evaluating order of _TMP and _CRT/_HOT/_PSV/_ACx.
1004  * 1. On HP Pavilion G4-1016tx, _TMP must be invoked after
1005  *    /_CRT/_HOT/_PSV/_ACx, or else system will be power off.
1006  * 2. On HP Compaq 6715b/6715s, the return value of _PSV is 0
1007  *    if _TMP has never been evaluated.
1008  *
1009  * As this dependency is totally transparent to OS, evaluate
1010  * all of them once, in the order of _CRT/_HOT/_PSV/_ACx,
1011  * _TMP, before they are actually used.
1012  */
1013 static void acpi_thermal_aml_dependency_fix(struct acpi_thermal *tz)
1014 {
1015         acpi_handle handle = tz->device->handle;
1016         unsigned long long value;
1017         int i;
1018
1019         acpi_evaluate_integer(handle, "_CRT", NULL, &value);
1020         acpi_evaluate_integer(handle, "_HOT", NULL, &value);
1021         acpi_evaluate_integer(handle, "_PSV", NULL, &value);
1022         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
1023                 char name[5] = { '_', 'A', 'C', ('0' + i), '\0' };
1024                 acpi_status status;
1025
1026                 status = acpi_evaluate_integer(handle, name, NULL, &value);
1027                 if (status == AE_NOT_FOUND)
1028                         break;
1029         }
1030         acpi_evaluate_integer(handle, "_TMP", NULL, &value);
1031 }
1032
1033 static int acpi_thermal_get_info(struct acpi_thermal *tz)
1034 {
1035         int result = 0;
1036
1037
1038         if (!tz)
1039                 return -EINVAL;
1040
1041         acpi_thermal_aml_dependency_fix(tz);
1042
1043         /* Get trip points [_CRT, _PSV, etc.] (required) */
1044         result = acpi_thermal_get_trip_points(tz);
1045         if (result)
1046                 return result;
1047
1048         /* Get temperature [_TMP] (required) */
1049         result = acpi_thermal_get_temperature(tz);
1050         if (result)
1051                 return result;
1052
1053         /* Set the cooling mode [_SCP] to active cooling (default) */
1054         result = acpi_thermal_set_cooling_mode(tz, ACPI_THERMAL_MODE_ACTIVE);
1055         if (!result)
1056                 tz->flags.cooling_mode = 1;
1057
1058         /* Get default polling frequency [_TZP] (optional) */
1059         if (tzp)
1060                 tz->polling_frequency = tzp;
1061         else
1062                 acpi_thermal_get_polling_frequency(tz);
1063
1064         return 0;
1065 }
1066
1067 /*
1068  * The exact offset between Kelvin and degree Celsius is 273.15. However ACPI
1069  * handles temperature values with a single decimal place. As a consequence,
1070  * some implementations use an offset of 273.1 and others use an offset of
1071  * 273.2. Try to find out which one is being used, to present the most
1072  * accurate and visually appealing number.
1073  *
1074  * The heuristic below should work for all ACPI thermal zones which have a
1075  * critical trip point with a value being a multiple of 0.5 degree Celsius.
1076  */
1077 static void acpi_thermal_guess_offset(struct acpi_thermal *tz)
1078 {
1079         if (tz->trips.critical.flags.valid &&
1080             (tz->trips.critical.temperature % 5) == 1)
1081                 tz->kelvin_offset = 2731;
1082         else
1083                 tz->kelvin_offset = 2732;
1084 }
1085
1086 static int acpi_thermal_add(struct acpi_device *device)
1087 {
1088         int result = 0;
1089         struct acpi_thermal *tz = NULL;
1090
1091
1092         if (!device)
1093                 return -EINVAL;
1094
1095         tz = kzalloc(sizeof(struct acpi_thermal), GFP_KERNEL);
1096         if (!tz)
1097                 return -ENOMEM;
1098
1099         tz->device = device;
1100         strcpy(tz->name, device->pnp.bus_id);
1101         strcpy(acpi_device_name(device), ACPI_THERMAL_DEVICE_NAME);
1102         strcpy(acpi_device_class(device), ACPI_THERMAL_CLASS);
1103         device->driver_data = tz;
1104         mutex_init(&tz->lock);
1105
1106
1107         result = acpi_thermal_get_info(tz);
1108         if (result)
1109                 goto free_memory;
1110
1111         acpi_thermal_guess_offset(tz);
1112
1113         result = acpi_thermal_register_thermal_zone(tz);
1114         if (result)
1115                 goto free_memory;
1116
1117         printk(KERN_INFO PREFIX "%s [%s] (%ld C)\n",
1118                acpi_device_name(device), acpi_device_bid(device),
1119                KELVIN_TO_CELSIUS(tz->temperature));
1120         goto end;
1121
1122 free_memory:
1123         kfree(tz);
1124 end:
1125         return result;
1126 }
1127
1128 static int acpi_thermal_remove(struct acpi_device *device)
1129 {
1130         struct acpi_thermal *tz = NULL;
1131
1132         if (!device || !acpi_driver_data(device))
1133                 return -EINVAL;
1134
1135         tz = acpi_driver_data(device);
1136
1137         acpi_thermal_unregister_thermal_zone(tz);
1138         mutex_destroy(&tz->lock);
1139         kfree(tz);
1140         return 0;
1141 }
1142
1143 #ifdef CONFIG_PM_SLEEP
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         acpi_thermal_check(tz);
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                 printk(KERN_NOTICE "ACPI: %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         printk(KERN_NOTICE "ACPI: %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                 printk(KERN_NOTICE "ACPI: %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                 printk(KERN_NOTICE "ACPI: %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                 printk(KERN_NOTICE "ACPI: thermal control disabled\n");
1263                 return -ENODEV;
1264         }
1265
1266         result = acpi_bus_register_driver(&acpi_thermal_driver);
1267         if (result < 0)
1268                 return -ENODEV;
1269
1270         return 0;
1271 }
1272
1273 static void __exit acpi_thermal_exit(void)
1274 {
1275
1276         acpi_bus_unregister_driver(&acpi_thermal_driver);
1277
1278         return;
1279 }
1280
1281 module_init(acpi_thermal_init);
1282 module_exit(acpi_thermal_exit);