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