drivers/acpi/bus.c

   1 /*
   2  *  acpi_bus.c - ACPI Bus Driver ($Revision: 80 $)
   3  *
   4  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   5  *
   6  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   7  *
   8  *  This program is free software; you can redistribute it and/or modify
   9  *  it under the terms of the GNU General Public License as published by
  10  *  the Free Software Foundation; either version 2 of the License, or (at
  11  *  your option) any later version.
  12  *
  13  *  This program is distributed in the hope that it will be useful, but
  14  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  *  General Public License for more details.
  17  *
  18  *  You should have received a copy of the GNU General Public License along
  19  *  with this program; if not, write to the Free Software Foundation, Inc.,
  20  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  21  *
  22  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  23  */
  24
  25 #include <linux/init.h>
  26 #include <linux/ioport.h>
  27 #include <linux/list.h>
  28 #include <linux/sched.h>
  29 #include <linux/pm.h>
  30 #include <linux/device.h>
  31 #include <linux/proc_fs.h>
  32 #ifdef CONFIG_X86
  33 #include <asm/mpspec.h>
  34 #endif
  35 #include <acpi/acpi_bus.h>
  36 #include <acpi/acpi_drivers.h>
  37
  38
  39 #define _COMPONENT              ACPI_BUS_COMPONENT
  40 ACPI_MODULE_NAME                ("acpi_bus")
  41
  42 #ifdef  CONFIG_X86
  43 extern void __init acpi_pic_sci_set_trigger(unsigned int irq, u16 trigger);
  44 #endif
  45
  46 FADT_DESCRIPTOR                 acpi_fadt;
  47 struct acpi_device              *acpi_root;
  48 struct proc_dir_entry           *acpi_root_dir;
  49
  50 #define STRUCT_TO_INT(s)        (*((int*)&s))
  51
  52 /* --------------------------------------------------------------------------
  53                                 Device Management
  54    -------------------------------------------------------------------------- */
  55
  56 extern void acpi_bus_data_handler (
  57         acpi_handle             handle,
  58         u32                     function,
  59         void                    *context);
  60 int
  61 acpi_bus_get_device (
  62         acpi_handle             handle,
  63         struct acpi_device      **device)
  64 {
  65         acpi_status             status = AE_OK;
  66
  67         ACPI_FUNCTION_TRACE("acpi_bus_get_device");
  68
  69         if (!device)
  70                 return_VALUE(-EINVAL);
  71
  72         /* TBD: Support fixed-feature devices */
  73
  74         status = acpi_get_data(handle, acpi_bus_data_handler, (void**) device);
  75         if (ACPI_FAILURE(status) || !*device) {
  76                 ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Error getting context for object [%p]\n",
  77                         handle));
  78                 return_VALUE(-ENODEV);
  79         }
  80
  81         return_VALUE(0);
  82 }
  83
  84 int
  85 acpi_bus_get_status (
  86         struct acpi_device      *device)
  87 {
  88         acpi_status             status = AE_OK;
  89         unsigned long           sta = 0;
  90
  91         ACPI_FUNCTION_TRACE("acpi_bus_get_status");
  92
  93         if (!device)
  94                 return_VALUE(-EINVAL);
  95
  96         /*
  97          * Evaluate _STA if present.
  98          */
  99         if (device->flags.dynamic_status) {
 100                 status = acpi_evaluate_integer(device->handle, "_STA", NULL, &sta);
 101                 if (ACPI_FAILURE(status))
 102                         return_VALUE(-ENODEV);
 103                 STRUCT_TO_INT(device->status) = (int) sta;
 104         }
 105
 106         /*
 107          * Otherwise we assume the status of our parent (unless we don't
 108          * have one, in which case status is implied).
 109          */
 110         else if (device->parent)
 111                 device->status = device->parent->status;
 112         else
 113                 STRUCT_TO_INT(device->status) = 0x0F;
 114
 115         if (device->status.functional && !device->status.present) {
 116                 printk(KERN_WARNING PREFIX "Device [%s] status [%08x]: "
 117                         "functional but not present; setting present\n",
 118                         device->pnp.bus_id,
 119                         (u32) STRUCT_TO_INT(device->status));
 120                 device->status.present = 1;
 121         }
 122
 123         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]\n",
 124                 device->pnp.bus_id, (u32) STRUCT_TO_INT(device->status)));
 125
 126         return_VALUE(0);
 127 }
 128
 129
 130 /* --------------------------------------------------------------------------
 131                                  Power Management
 132    -------------------------------------------------------------------------- */
 133
 134 int
 135 acpi_bus_get_power (
 136         acpi_handle             handle,
 137         int                     *state)
 138 {
 139         int                     result = 0;
 140         acpi_status             status = 0;
 141         struct acpi_device      *device = NULL;
 142         unsigned long           psc = 0;
 143
 144         ACPI_FUNCTION_TRACE("acpi_bus_get_power");
 145
 146         result = acpi_bus_get_device(handle, &device);
 147         if (result)
 148                 return_VALUE(result);
 149
 150         *state = ACPI_STATE_UNKNOWN;
 151
 152         if (!device->flags.power_manageable) {
 153                 /* TBD: Non-recursive algorithm for walking up hierarchy */
 154                 if (device->parent)
 155                         *state = device->parent->power.state;
 156                 else
 157                         *state = ACPI_STATE_D0;
 158         }
 159         else {
 160                 /*
 161                  * Get the device's power state either directly (via _PSC) or
 162                  * indirectly (via power resources).
 163                  */
 164                 if (device->power.flags.explicit_get) {
 165                         status = acpi_evaluate_integer(device->handle, "_PSC",
 166                                 NULL, &psc);
 167                         if (ACPI_FAILURE(status))
 168                                 return_VALUE(-ENODEV);
 169                         device->power.state = (int) psc;
 170                 }
 171                 else if (device->power.flags.power_resources) {
 172                         result = acpi_power_get_inferred_state(device);
 173                         if (result)
 174                                 return_VALUE(result);
 175                 }
 176
 177                 *state = device->power.state;
 178         }
 179
 180         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] power state is D%d\n",
 181                 device->pnp.bus_id, device->power.state));
 182
 183         return_VALUE(0);
 184 }
 185
 186
 187 int
 188 acpi_bus_set_power (
 189         acpi_handle             handle,
 190         int                     state)
 191 {
 192         int                     result = 0;
 193         acpi_status             status = AE_OK;
 194         struct acpi_device      *device = NULL;
 195         char                    object_name[5] = {'_','P','S','0'+state,'\0'};
 196
 197         ACPI_FUNCTION_TRACE("acpi_bus_set_power");
 198
 199         result = acpi_bus_get_device(handle, &device);
 200         if (result)
 201                 return_VALUE(result);
 202
 203         if ((state < ACPI_STATE_D0) || (state > ACPI_STATE_D3))
 204                 return_VALUE(-EINVAL);
 205
 206         /* Make sure this is a valid target state */
 207
 208         if (!device->flags.power_manageable) {
 209                 ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Device is not power manageable\n"));
 210                 return_VALUE(-ENODEV);
 211         }
 212         if (state == device->power.state) {
 213                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device is already at D%d\n", state));
 214                 return_VALUE(0);
 215         }
 216         if (!device->power.states[state].flags.valid) {
 217                 ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Device does not support D%d\n", state));
 218                 return_VALUE(-ENODEV);
 219         }
 220         if (device->parent && (state < device->parent->power.state)) {
 221                 ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Cannot set device to a higher-powered state than parent\n"));
 222                 return_VALUE(-ENODEV);
 223         }
 224
 225         /*
 226          * Transition Power
 227          * ----------------
 228          * On transitions to a high-powered state we first apply power (via
 229          * power resources) then evalute _PSx.  Conversly for transitions to
 230          * a lower-powered state.
 231          */
 232         if (state < device->power.state) {
 233                 if (device->power.flags.power_resources) {
 234                         result = acpi_power_transition(device, state);
 235                         if (result)
 236                                 goto end;
 237                 }
 238                 if (device->power.states[state].flags.explicit_set) {
 239                         status = acpi_evaluate_object(device->handle,
 240                                 object_name, NULL, NULL);
 241                         if (ACPI_FAILURE(status)) {
 242                                 result = -ENODEV;
 243                                 goto end;
 244                         }
 245                 }
 246         }
 247         else {
 248                 if (device->power.states[state].flags.explicit_set) {
 249                         status = acpi_evaluate_object(device->handle,
 250                                 object_name, NULL, NULL);
 251                         if (ACPI_FAILURE(status)) {
 252                                 result = -ENODEV;
 253                                 goto end;
 254                         }
 255                 }
 256                 if (device->power.flags.power_resources) {
 257                         result = acpi_power_transition(device, state);
 258                         if (result)
 259                                 goto end;
 260                 }
 261         }
 262
 263 end:
 264         if (result)
 265                 ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Error transitioning device [%s] to D%d\n",
 266                         device->pnp.bus_id, state));
 267         else
 268                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] transitioned to D%d\n",
 269                         device->pnp.bus_id, state));
 270
 271         return_VALUE(result);
 272 }
 273
 274
 275
 276 /* --------------------------------------------------------------------------
 277                                 Event Management
 278    -------------------------------------------------------------------------- */
 279
 280 static spinlock_t               acpi_bus_event_lock = SPIN_LOCK_UNLOCKED;
 281
 282 LIST_HEAD(acpi_bus_event_list);
 283 DECLARE_WAIT_QUEUE_HEAD(acpi_bus_event_queue);
 284
 285 extern int                      event_is_open;
 286
 287 int
 288 acpi_bus_generate_event (
 289         struct acpi_device      *device,
 290         u8                      type,
 291         int                     data)
 292 {
 293         struct acpi_bus_event   *event = NULL;
 294         unsigned long           flags = 0;
 295
 296         ACPI_FUNCTION_TRACE("acpi_bus_generate_event");
 297
 298         if (!device)
 299                 return_VALUE(-EINVAL);
 300
 301         /* drop event on the floor if no one's listening */
 302         if (!event_is_open)
 303                 return_VALUE(0);
 304
 305         event = kmalloc(sizeof(struct acpi_bus_event), GFP_ATOMIC);
 306         if (!event)
 307                 return_VALUE(-ENOMEM);
 308
 309         strcpy(event->device_class, device->pnp.device_class);
 310         strcpy(event->bus_id, device->pnp.bus_id);
 311         event->type = type;
 312         event->data = data;
 313
 314         spin_lock_irqsave(&acpi_bus_event_lock, flags);
 315         list_add_tail(&event->node, &acpi_bus_event_list);
 316         spin_unlock_irqrestore(&acpi_bus_event_lock, flags);
 317
 318         wake_up_interruptible(&acpi_bus_event_queue);
 319
 320         return_VALUE(0);
 321 }
 322
 323 int
 324 acpi_bus_receive_event (
 325         struct acpi_bus_event   *event)
 326 {
 327         unsigned long           flags = 0;
 328         struct acpi_bus_event   *entry = NULL;
 329
 330         DECLARE_WAITQUEUE(wait, current);
 331
 332         ACPI_FUNCTION_TRACE("acpi_bus_receive_event");
 333
 334         if (!event)
 335                 return -EINVAL;
 336
 337         if (list_empty(&acpi_bus_event_list)) {
 338
 339                 set_current_state(TASK_INTERRUPTIBLE);
 340                 add_wait_queue(&acpi_bus_event_queue, &wait);
 341
 342                 if (list_empty(&acpi_bus_event_list))
 343                         schedule();
 344
 345                 remove_wait_queue(&acpi_bus_event_queue, &wait);
 346                 set_current_state(TASK_RUNNING);
 347
 348                 if (signal_pending(current))
 349                         return_VALUE(-ERESTARTSYS);
 350         }
 351
 352         spin_lock_irqsave(&acpi_bus_event_lock, flags);
 353         entry = list_entry(acpi_bus_event_list.next, struct acpi_bus_event, node);
 354         if (entry)
 355                 list_del(&entry->node);
 356         spin_unlock_irqrestore(&acpi_bus_event_lock, flags);
 357
 358         if (!entry)
 359                 return_VALUE(-ENODEV);
 360
 361         memcpy(event, entry, sizeof(struct acpi_bus_event));
 362
 363         kfree(entry);
 364
 365         return_VALUE(0);
 366 }
 367
 368
 369 /* --------------------------------------------------------------------------
 370                              Notification Handling
 371    -------------------------------------------------------------------------- */
 372
 373 static int
 374 acpi_bus_check_device (
 375         struct acpi_device      *device,
 376         int                     *status_changed)
 377 {
 378         acpi_status             status = 0;
 379         struct acpi_device_status old_status;
 380
 381         ACPI_FUNCTION_TRACE("acpi_bus_check_device");
 382
 383         if (!device)
 384                 return_VALUE(-EINVAL);
 385
 386         if (status_changed)
 387                 *status_changed = 0;
 388
 389         old_status = device->status;
 390
 391         /*
 392          * Make sure this device's parent is present before we go about
 393          * messing with the device.
 394          */
 395         if (device->parent && !device->parent->status.present) {
 396                 device->status = device->parent->status;
 397                 if (STRUCT_TO_INT(old_status) != STRUCT_TO_INT(device->status)) {
 398                         if (status_changed)
 399                                 *status_changed = 1;
 400                 }
 401                 return_VALUE(0);
 402         }
 403
 404         status = acpi_bus_get_status(device);
 405         if (ACPI_FAILURE(status))
 406                 return_VALUE(-ENODEV);
 407
 408         if (STRUCT_TO_INT(old_status) == STRUCT_TO_INT(device->status))
 409                 return_VALUE(0);
 410
 411         if (status_changed)
 412                 *status_changed = 1;
 413
 414         /*
 415          * Device Insertion/Removal
 416          */
 417         if ((device->status.present) && !(old_status.present)) {
 418                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device insertion detected\n"));
 419                 /* TBD: Handle device insertion */
 420         }
 421         else if (!(device->status.present) && (old_status.present)) {
 422                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device removal detected\n"));
 423                 /* TBD: Handle device removal */
 424         }
 425
 426         return_VALUE(0);
 427 }
 428
 429
 430 static int
 431 acpi_bus_check_scope (
 432         struct acpi_device      *device)
 433 {
 434         int                     result = 0;
 435         int                     status_changed = 0;
 436
 437         ACPI_FUNCTION_TRACE("acpi_bus_check_scope");
 438
 439         if (!device)
 440                 return_VALUE(-EINVAL);
 441
 442         /* Status Change? */
 443         result = acpi_bus_check_device(device, &status_changed);
 444         if (result)
 445                 return_VALUE(result);
 446
 447         if (!status_changed)
 448                 return_VALUE(0);
 449
 450         /*
 451          * TBD: Enumerate child devices within this device's scope and
 452          *       run acpi_bus_check_device()'s on them.
 453          */
 454
 455         return_VALUE(0);
 456 }
 457
 458
 459 /**
 460  * acpi_bus_notify
 461  * ---------------
 462  * Callback for all 'system-level' device notifications (values 0x00-0x7F).
 463  */
 464 static void
 465 acpi_bus_notify (
 466         acpi_handle             handle,
 467         u32                     type,
 468         void                    *data)
 469 {
 470         int                     result = 0;
 471         struct acpi_device      *device = NULL;
 472
 473         ACPI_FUNCTION_TRACE("acpi_bus_notify");
 474
 475         if (acpi_bus_get_device(handle, &device))
 476                 return_VOID;
 477
 478         switch (type) {
 479
 480         case ACPI_NOTIFY_BUS_CHECK:
 481                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Received BUS CHECK notification for device [%s]\n",
 482                         device->pnp.bus_id));
 483                 result = acpi_bus_check_scope(device);
 484                 /*
 485                  * TBD: We'll need to outsource certain events to non-ACPI
 486                  *      drivers via the device manager (device.c).
 487                  */
 488                 break;
 489
 490         case ACPI_NOTIFY_DEVICE_CHECK:
 491                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Received DEVICE CHECK notification for device [%s]\n",
 492                         device->pnp.bus_id));
 493                 result = acpi_bus_check_device(device, NULL);
 494                 /*
 495                  * TBD: We'll need to outsource certain events to non-ACPI
 496                  *      drivers via the device manager (device.c).
 497                  */
 498                 break;
 499
 500         case ACPI_NOTIFY_DEVICE_WAKE:
 501                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Received DEVICE WAKE notification for device [%s]\n",
 502                         device->pnp.bus_id));
 503                 /* TBD */
 504                 break;
 505
 506         case ACPI_NOTIFY_EJECT_REQUEST:
 507                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Received EJECT REQUEST notification for device [%s]\n",
 508                         device->pnp.bus_id));
 509                 /* TBD */
 510                 break;
 511
 512         case ACPI_NOTIFY_DEVICE_CHECK_LIGHT:
 513                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Received DEVICE CHECK LIGHT notification for device [%s]\n",
 514                         device->pnp.bus_id));
 515                 /* TBD: Exactly what does 'light' mean? */
 516                 break;
 517
 518         case ACPI_NOTIFY_FREQUENCY_MISMATCH:
 519                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Received FREQUENCY MISMATCH notification for device [%s]\n",
 520                         device->pnp.bus_id));
 521                 /* TBD */
 522                 break;
 523
 524         case ACPI_NOTIFY_BUS_MODE_MISMATCH:
 525                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Received BUS MODE MISMATCH notification for device [%s]\n",
 526                         device->pnp.bus_id));
 527                 /* TBD */
 528                 break;
 529
 530         case ACPI_NOTIFY_POWER_FAULT:
 531                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Received POWER FAULT notification for device [%s]\n",
 532                         device->pnp.bus_id));
 533                 /* TBD */
 534                 break;
 535
 536         default:
 537                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Received unknown/unsupported notification [%08x]\n",
 538                         type));
 539                 break;
 540         }
 541
 542         return_VOID;
 543 }
 544
 545 /* --------------------------------------------------------------------------
 546                              Initialization/Cleanup
 547    -------------------------------------------------------------------------- */
 548
 549 static int __init
 550 acpi_bus_init_irq (void)
 551 {
 552         acpi_status             status = AE_OK;
 553         union acpi_object       arg = {ACPI_TYPE_INTEGER};
 554         struct acpi_object_list arg_list = {1, &arg};
 555         char                    *message = NULL;
 556
 557         ACPI_FUNCTION_TRACE("acpi_bus_init_irq");
 558
 559         /*
 560          * Let the system know what interrupt model we are using by
 561          * evaluating the \_PIC object, if exists.
 562          */
 563
 564         switch (acpi_irq_model) {
 565         case ACPI_IRQ_MODEL_PIC:
 566                 message = "PIC";
 567                 break;
 568         case ACPI_IRQ_MODEL_IOAPIC:
 569                 message = "IOAPIC";
 570                 break;
 571         case ACPI_IRQ_MODEL_IOSAPIC:
 572                 message = "IOSAPIC";
 573                 break;
 574         default:
 575                 printk(KERN_WARNING PREFIX "Unknown interrupt routing model\n");
 576                 return_VALUE(-ENODEV);
 577         }
 578
 579         printk(KERN_INFO PREFIX "Using %s for interrupt routing\n", message);
 580
 581         arg.integer.value = acpi_irq_model;
 582
 583         status = acpi_evaluate_object(NULL, "\\_PIC", &arg_list, NULL);
 584         if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
 585                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PIC\n"));
 586                 return_VALUE(-ENODEV);
 587         }
 588
 589         return_VALUE(0);
 590 }
 591
 592
 593 static int __init
 594 acpi_bus_init (void)
 595 {
 596         int                     result = 0;
 597         acpi_status             status = AE_OK;
 598         struct acpi_buffer      buffer = {sizeof(acpi_fadt), &acpi_fadt};
 599
 600         ACPI_FUNCTION_TRACE("acpi_bus_init");
 601
 602         status = acpi_initialize_subsystem();
 603         if (ACPI_FAILURE(status)) {
 604                 printk(KERN_ERR PREFIX "Unable to initialize the ACPI Interpreter\n");
 605                 goto error0;
 606         }
 607
 608         status = acpi_load_tables();
 609         if (ACPI_FAILURE(status)) {
 610                 printk(KERN_ERR PREFIX "Unable to load the System Description Tables\n");
 611                 goto error0;
 612         }
 613
 614         /*
 615          * Get a separate copy of the FADT for use by other drivers.
 616          */
 617         status = acpi_get_table(ACPI_TABLE_FADT, 1, &buffer);
 618         if (ACPI_FAILURE(status)) {
 619                 printk(KERN_ERR PREFIX "Unable to get the FADT\n");
 620                 goto error1;
 621         }
 622
 623 #ifdef CONFIG_X86
 624         if (!acpi_ioapic) {
 625                 extern acpi_interrupt_flags acpi_sci_flags;
 626
 627                 /* compatible (0) means level (3) */
 628                 if (acpi_sci_flags.trigger == 0)
 629                         acpi_sci_flags.trigger = 3;
 630
 631                 /* Set PIC-mode SCI trigger type */
 632                 acpi_pic_sci_set_trigger(acpi_fadt.sci_int, acpi_sci_flags.trigger);
 633         } else {
 634                 extern int acpi_sci_override_gsi;
 635                 /*
 636                  * now that acpi_fadt is initialized,
 637                  * update it with result from INT_SRC_OVR parsing
 638                  */
 639                 acpi_fadt.sci_int = acpi_sci_override_gsi;
 640         }
 641 #endif
 642
 643         status = acpi_enable_subsystem(ACPI_FULL_INITIALIZATION);
 644         if (ACPI_FAILURE(status)) {
 645                 printk(KERN_ERR PREFIX "Unable to start the ACPI Interpreter\n");
 646                 goto error1;
 647         }
 648
 649 #ifdef CONFIG_ACPI_EC
 650         /*
 651          * ACPI 2.0 requires the EC driver to be loaded and work before
 652          * the EC device is found in the namespace (i.e. before acpi_initialize_objects()
 653          * is called).
 654          *
 655          * This is accomplished by looking for the ECDT table, and getting
 656          * the EC parameters out of that.
 657          */
 658         status = acpi_ec_ecdt_probe();
 659         /* Ignore result. Not having an ECDT is not fatal. */
 660 #endif
 661
 662         status = acpi_initialize_objects(ACPI_FULL_INITIALIZATION);
 663         if (ACPI_FAILURE(status)) {
 664                 printk(KERN_ERR PREFIX "Unable to initialize ACPI objects\n");
 665                 goto error1;
 666         }
 667
 668         printk(KERN_INFO PREFIX "Interpreter enabled\n");
 669
 670         /*
 671          * Get the system interrupt model and evaluate \_PIC.
 672          */
 673         result = acpi_bus_init_irq();
 674         if (result)
 675                 goto error1;
 676
 677         /*
 678          * Register the for all standard device notifications.
 679          */
 680         status = acpi_install_notify_handler(ACPI_ROOT_OBJECT, ACPI_SYSTEM_NOTIFY, &acpi_bus_notify, NULL);
 681         if (ACPI_FAILURE(status)) {
 682                 printk(KERN_ERR PREFIX "Unable to register for device notifications\n");
 683                 goto error1;
 684         }
 685
 686         /*
 687          * Create the top ACPI proc directory
 688          */
 689         acpi_root_dir = proc_mkdir(ACPI_BUS_FILE_ROOT, NULL);
 690
 691         return_VALUE(0);
 692
 693         /* Mimic structured exception handling */
 694 error1:
 695         acpi_terminate();
 696 error0:
 697         return_VALUE(-ENODEV);
 698 }
 699
 700 decl_subsys(acpi,NULL,NULL);
 701
 702 static int __init acpi_init (void)
 703 {
 704         int                     result = 0;
 705
 706         ACPI_FUNCTION_TRACE("acpi_init");
 707
 708         printk(KERN_INFO PREFIX "Subsystem revision %08x\n",
 709                 ACPI_CA_VERSION);
 710
 711         /* Initial core debug level excludes drivers, so include them now */
 712         acpi_set_debug(ACPI_DEBUG_LOW);
 713
 714         if (acpi_disabled) {
 715                 printk(KERN_INFO PREFIX "Interpreter disabled.\n");
 716                 return -ENODEV;
 717         }
 718
 719         firmware_register(&acpi_subsys);
 720
 721         result = acpi_bus_init();
 722
 723         if (!result) {
 724 #ifdef CONFIG_PM
 725                 if (!PM_IS_ACTIVE())
 726                         pm_active = 1;
 727                 else {
 728                         printk(KERN_INFO PREFIX "APM is already active, exiting\n");
 729                         disable_acpi();
 730                         result = -ENODEV;
 731                 }
 732 #endif
 733         } else
 734                 disable_acpi();
 735
 736         return_VALUE(result);
 737 }
 738
 739 subsys_initcall(acpi_init);