ACPI: fix fan after resume from S3
[linux-2.6.git] / 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/module.h>
26 #include <linux/init.h>
27 #include <linux/ioport.h>
28 #include <linux/kernel.h>
29 #include <linux/list.h>
30 #include <linux/sched.h>
31 #include <linux/pm.h>
32 #include <linux/pm_legacy.h>
33 #include <linux/device.h>
34 #include <linux/proc_fs.h>
35 #ifdef CONFIG_X86
36 #include <asm/mpspec.h>
37 #endif
38 #include <acpi/acpi_bus.h>
39 #include <acpi/acpi_drivers.h>
40
41 #define _COMPONENT              ACPI_BUS_COMPONENT
42 ACPI_MODULE_NAME("acpi_bus")
43 #ifdef  CONFIG_X86
44 extern void __init acpi_pic_sci_set_trigger(unsigned int irq, u16 trigger);
45 #endif
46
47 struct acpi_device *acpi_root;
48 struct proc_dir_entry *acpi_root_dir;
49 EXPORT_SYMBOL(acpi_root_dir);
50
51 #define STRUCT_TO_INT(s)        (*((int*)&s))
52
53 /* --------------------------------------------------------------------------
54                                 Device Management
55    -------------------------------------------------------------------------- */
56
57 int acpi_bus_get_device(acpi_handle handle, struct acpi_device **device)
58 {
59         acpi_status status = AE_OK;
60
61
62         if (!device)
63                 return -EINVAL;
64
65         /* TBD: Support fixed-feature devices */
66
67         status = acpi_get_data(handle, acpi_bus_data_handler, (void **)device);
68         if (ACPI_FAILURE(status) || !*device) {
69                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No context for object [%p]\n",
70                                   handle));
71                 return -ENODEV;
72         }
73
74         return 0;
75 }
76
77 EXPORT_SYMBOL(acpi_bus_get_device);
78
79 int acpi_bus_get_status(struct acpi_device *device)
80 {
81         acpi_status status = AE_OK;
82         unsigned long sta = 0;
83
84
85         if (!device)
86                 return -EINVAL;
87
88         /*
89          * Evaluate _STA if present.
90          */
91         if (device->flags.dynamic_status) {
92                 status =
93                     acpi_evaluate_integer(device->handle, "_STA", NULL, &sta);
94                 if (ACPI_FAILURE(status))
95                         return -ENODEV;
96                 STRUCT_TO_INT(device->status) = (int)sta;
97         }
98
99         /*
100          * Otherwise we assume the status of our parent (unless we don't
101          * have one, in which case status is implied).
102          */
103         else if (device->parent)
104                 device->status = device->parent->status;
105         else
106                 STRUCT_TO_INT(device->status) = 0x0F;
107
108         if (device->status.functional && !device->status.present) {
109                 printk(KERN_WARNING PREFIX "Device [%s] status [%08x]: "
110                        "functional but not present; setting present\n",
111                        device->pnp.bus_id, (u32) STRUCT_TO_INT(device->status));
112                 device->status.present = 1;
113         }
114
115         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]\n",
116                           device->pnp.bus_id,
117                           (u32) STRUCT_TO_INT(device->status)));
118
119         return 0;
120 }
121
122 EXPORT_SYMBOL(acpi_bus_get_status);
123
124 /* --------------------------------------------------------------------------
125                                  Power Management
126    -------------------------------------------------------------------------- */
127
128 int acpi_bus_get_power(acpi_handle handle, int *state)
129 {
130         int result = 0;
131         acpi_status status = 0;
132         struct acpi_device *device = NULL;
133         unsigned long psc = 0;
134
135
136         result = acpi_bus_get_device(handle, &device);
137         if (result)
138                 return result;
139
140         *state = ACPI_STATE_UNKNOWN;
141
142         if (!device->flags.power_manageable) {
143                 /* TBD: Non-recursive algorithm for walking up hierarchy */
144                 if (device->parent)
145                         *state = device->parent->power.state;
146                 else
147                         *state = ACPI_STATE_D0;
148         } else {
149                 /*
150                  * Get the device's power state either directly (via _PSC) or 
151                  * indirectly (via power resources).
152                  */
153                 if (device->power.flags.explicit_get) {
154                         status = acpi_evaluate_integer(device->handle, "_PSC",
155                                                        NULL, &psc);
156                         if (ACPI_FAILURE(status))
157                                 return -ENODEV;
158                         device->power.state = (int)psc;
159                 } else if (device->power.flags.power_resources) {
160                         result = acpi_power_get_inferred_state(device);
161                         if (result)
162                                 return result;
163                 }
164
165                 *state = device->power.state;
166         }
167
168         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] power state is D%d\n",
169                           device->pnp.bus_id, device->power.state));
170
171         return 0;
172 }
173
174 EXPORT_SYMBOL(acpi_bus_get_power);
175
176 int acpi_bus_set_power(acpi_handle handle, int state)
177 {
178         int result = 0;
179         acpi_status status = AE_OK;
180         struct acpi_device *device = NULL;
181         char object_name[5] = { '_', 'P', 'S', '0' + state, '\0' };
182
183
184         result = acpi_bus_get_device(handle, &device);
185         if (result)
186                 return result;
187
188         if ((state < ACPI_STATE_D0) || (state > ACPI_STATE_D3))
189                 return -EINVAL;
190
191         /* Make sure this is a valid target state */
192
193         if (!device->flags.power_manageable) {
194                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device `[%s]' is not power manageable\n",
195                                 device->dev.kobj.name));
196                 return -ENODEV;
197         }
198         /*
199          * Get device's current power state if it's unknown
200          * This means device power state isn't initialized or previous setting failed
201          */
202         if ((device->power.state == ACPI_STATE_UNKNOWN) || device->flags.force_power_state)
203                 acpi_bus_get_power(device->handle, &device->power.state);
204         if ((state == device->power.state) && !device->flags.force_power_state) {
205                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device is already at D%d\n",
206                                   state));
207                 return 0;
208         }
209
210         if (!device->power.states[state].flags.valid) {
211                 printk(KERN_WARNING PREFIX "Device does not support D%d\n", state);
212                 return -ENODEV;
213         }
214         if (device->parent && (state < device->parent->power.state)) {
215                 printk(KERN_WARNING PREFIX
216                               "Cannot set device to a higher-powered"
217                               " state than parent\n");
218                 return -ENODEV;
219         }
220
221         /*
222          * Transition Power
223          * ----------------
224          * On transitions to a high-powered state we first apply power (via
225          * power resources) then evalute _PSx.  Conversly for transitions to
226          * a lower-powered state.
227          */
228         if (state < device->power.state) {
229                 if (device->power.flags.power_resources) {
230                         result = acpi_power_transition(device, state);
231                         if (result)
232                                 goto end;
233                 }
234                 if (device->power.states[state].flags.explicit_set) {
235                         status = acpi_evaluate_object(device->handle,
236                                                       object_name, NULL, NULL);
237                         if (ACPI_FAILURE(status)) {
238                                 result = -ENODEV;
239                                 goto end;
240                         }
241                 }
242         } else {
243                 if (device->power.states[state].flags.explicit_set) {
244                         status = acpi_evaluate_object(device->handle,
245                                                       object_name, NULL, NULL);
246                         if (ACPI_FAILURE(status)) {
247                                 result = -ENODEV;
248                                 goto end;
249                         }
250                 }
251                 if (device->power.flags.power_resources) {
252                         result = acpi_power_transition(device, state);
253                         if (result)
254                                 goto end;
255                 }
256         }
257
258       end:
259         if (result)
260                 printk(KERN_WARNING PREFIX
261                               "Transitioning device [%s] to D%d\n",
262                               device->pnp.bus_id, state);
263         else
264                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
265                                   "Device [%s] transitioned to D%d\n",
266                                   device->pnp.bus_id, state));
267
268         return result;
269 }
270
271 EXPORT_SYMBOL(acpi_bus_set_power);
272
273 /* --------------------------------------------------------------------------
274                                 Event Management
275    -------------------------------------------------------------------------- */
276
277 static DEFINE_SPINLOCK(acpi_bus_event_lock);
278
279 LIST_HEAD(acpi_bus_event_list);
280 DECLARE_WAIT_QUEUE_HEAD(acpi_bus_event_queue);
281
282 extern int event_is_open;
283
284 int acpi_bus_generate_event(struct acpi_device *device, u8 type, int data)
285 {
286         struct acpi_bus_event *event = NULL;
287         unsigned long flags = 0;
288
289
290         if (!device)
291                 return -EINVAL;
292
293         /* drop event on the floor if no one's listening */
294         if (!event_is_open)
295                 return 0;
296
297         event = kmalloc(sizeof(struct acpi_bus_event), GFP_ATOMIC);
298         if (!event)
299                 return -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 0;
313 }
314
315 EXPORT_SYMBOL(acpi_bus_generate_event);
316
317 int acpi_bus_receive_event(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
325         if (!event)
326                 return -EINVAL;
327
328         if (list_empty(&acpi_bus_event_list)) {
329
330                 set_current_state(TASK_INTERRUPTIBLE);
331                 add_wait_queue(&acpi_bus_event_queue, &wait);
332
333                 if (list_empty(&acpi_bus_event_list))
334                         schedule();
335
336                 remove_wait_queue(&acpi_bus_event_queue, &wait);
337                 set_current_state(TASK_RUNNING);
338
339                 if (signal_pending(current))
340                         return -ERESTARTSYS;
341         }
342
343         spin_lock_irqsave(&acpi_bus_event_lock, flags);
344         entry =
345             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 -ENODEV;
352
353         memcpy(event, entry, sizeof(struct acpi_bus_event));
354
355         kfree(entry);
356
357         return 0;
358 }
359
360 EXPORT_SYMBOL(acpi_bus_receive_event);
361
362 /* --------------------------------------------------------------------------
363                              Notification Handling
364    -------------------------------------------------------------------------- */
365
366 static int
367 acpi_bus_check_device(struct acpi_device *device, int *status_changed)
368 {
369         acpi_status status = 0;
370         struct acpi_device_status old_status;
371
372
373         if (!device)
374                 return -EINVAL;
375
376         if (status_changed)
377                 *status_changed = 0;
378
379         old_status = device->status;
380
381         /*
382          * Make sure this device's parent is present before we go about
383          * messing with the device.
384          */
385         if (device->parent && !device->parent->status.present) {
386                 device->status = device->parent->status;
387                 if (STRUCT_TO_INT(old_status) != STRUCT_TO_INT(device->status)) {
388                         if (status_changed)
389                                 *status_changed = 1;
390                 }
391                 return 0;
392         }
393
394         status = acpi_bus_get_status(device);
395         if (ACPI_FAILURE(status))
396                 return -ENODEV;
397
398         if (STRUCT_TO_INT(old_status) == STRUCT_TO_INT(device->status))
399                 return 0;
400
401         if (status_changed)
402                 *status_changed = 1;
403
404         /*
405          * Device Insertion/Removal
406          */
407         if ((device->status.present) && !(old_status.present)) {
408                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device insertion detected\n"));
409                 /* TBD: Handle device insertion */
410         } else if (!(device->status.present) && (old_status.present)) {
411                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device removal detected\n"));
412                 /* TBD: Handle device removal */
413         }
414
415         return 0;
416 }
417
418 static int acpi_bus_check_scope(struct acpi_device *device)
419 {
420         int result = 0;
421         int status_changed = 0;
422
423
424         if (!device)
425                 return -EINVAL;
426
427         /* Status Change? */
428         result = acpi_bus_check_device(device, &status_changed);
429         if (result)
430                 return result;
431
432         if (!status_changed)
433                 return 0;
434
435         /*
436          * TBD: Enumerate child devices within this device's scope and
437          *       run acpi_bus_check_device()'s on them.
438          */
439
440         return 0;
441 }
442
443 /**
444  * acpi_bus_notify
445  * ---------------
446  * Callback for all 'system-level' device notifications (values 0x00-0x7F).
447  */
448 static void acpi_bus_notify(acpi_handle handle, u32 type, void *data)
449 {
450         int result = 0;
451         struct acpi_device *device = NULL;
452
453
454         if (acpi_bus_get_device(handle, &device))
455                 return;
456
457         switch (type) {
458
459         case ACPI_NOTIFY_BUS_CHECK:
460                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
461                                   "Received BUS CHECK notification for device [%s]\n",
462                                   device->pnp.bus_id));
463                 result = acpi_bus_check_scope(device);
464                 /* 
465                  * TBD: We'll need to outsource certain events to non-ACPI
466                  *      drivers via the device manager (device.c).
467                  */
468                 break;
469
470         case ACPI_NOTIFY_DEVICE_CHECK:
471                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
472                                   "Received DEVICE CHECK notification for device [%s]\n",
473                                   device->pnp.bus_id));
474                 result = acpi_bus_check_device(device, NULL);
475                 /* 
476                  * TBD: We'll need to outsource certain events to non-ACPI
477                  *      drivers via the device manager (device.c).
478                  */
479                 break;
480
481         case ACPI_NOTIFY_DEVICE_WAKE:
482                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
483                                   "Received DEVICE WAKE notification for device [%s]\n",
484                                   device->pnp.bus_id));
485                 /* TBD */
486                 break;
487
488         case ACPI_NOTIFY_EJECT_REQUEST:
489                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
490                                   "Received EJECT REQUEST notification for device [%s]\n",
491                                   device->pnp.bus_id));
492                 /* TBD */
493                 break;
494
495         case ACPI_NOTIFY_DEVICE_CHECK_LIGHT:
496                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
497                                   "Received DEVICE CHECK LIGHT notification for device [%s]\n",
498                                   device->pnp.bus_id));
499                 /* TBD: Exactly what does 'light' mean? */
500                 break;
501
502         case ACPI_NOTIFY_FREQUENCY_MISMATCH:
503                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
504                                   "Received FREQUENCY MISMATCH notification for device [%s]\n",
505                                   device->pnp.bus_id));
506                 /* TBD */
507                 break;
508
509         case ACPI_NOTIFY_BUS_MODE_MISMATCH:
510                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
511                                   "Received BUS MODE MISMATCH notification for device [%s]\n",
512                                   device->pnp.bus_id));
513                 /* TBD */
514                 break;
515
516         case ACPI_NOTIFY_POWER_FAULT:
517                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
518                                   "Received POWER FAULT notification for device [%s]\n",
519                                   device->pnp.bus_id));
520                 /* TBD */
521                 break;
522
523         default:
524                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
525                                   "Received unknown/unsupported notification [%08x]\n",
526                                   type));
527                 break;
528         }
529
530         return;
531 }
532
533 /* --------------------------------------------------------------------------
534                              Initialization/Cleanup
535    -------------------------------------------------------------------------- */
536
537 static int __init acpi_bus_init_irq(void)
538 {
539         acpi_status status = AE_OK;
540         union acpi_object arg = { ACPI_TYPE_INTEGER };
541         struct acpi_object_list arg_list = { 1, &arg };
542         char *message = NULL;
543
544
545         /* 
546          * Let the system know what interrupt model we are using by
547          * evaluating the \_PIC object, if exists.
548          */
549
550         switch (acpi_irq_model) {
551         case ACPI_IRQ_MODEL_PIC:
552                 message = "PIC";
553                 break;
554         case ACPI_IRQ_MODEL_IOAPIC:
555                 message = "IOAPIC";
556                 break;
557         case ACPI_IRQ_MODEL_IOSAPIC:
558                 message = "IOSAPIC";
559                 break;
560         case ACPI_IRQ_MODEL_PLATFORM:
561                 message = "platform specific model";
562                 break;
563         default:
564                 printk(KERN_WARNING PREFIX "Unknown interrupt routing model\n");
565                 return -ENODEV;
566         }
567
568         printk(KERN_INFO PREFIX "Using %s for interrupt routing\n", message);
569
570         arg.integer.value = acpi_irq_model;
571
572         status = acpi_evaluate_object(NULL, "\\_PIC", &arg_list, NULL);
573         if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
574                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PIC"));
575                 return -ENODEV;
576         }
577
578         return 0;
579 }
580
581 acpi_native_uint acpi_gbl_permanent_mmap;
582
583
584 void __init acpi_early_init(void)
585 {
586         acpi_status status = AE_OK;
587
588         if (acpi_disabled)
589                 return;
590
591         printk(KERN_INFO PREFIX "Core revision %08x\n", ACPI_CA_VERSION);
592
593         /* enable workarounds, unless strict ACPI spec. compliance */
594         if (!acpi_strict)
595                 acpi_gbl_enable_interpreter_slack = TRUE;
596
597         acpi_gbl_permanent_mmap = 1;
598
599         status = acpi_reallocate_root_table();
600         if (ACPI_FAILURE(status)) {
601                 printk(KERN_ERR PREFIX
602                        "Unable to reallocate ACPI tables\n");
603                 goto error0;
604         }
605
606         status = acpi_initialize_subsystem();
607         if (ACPI_FAILURE(status)) {
608                 printk(KERN_ERR PREFIX
609                        "Unable to initialize the ACPI Interpreter\n");
610                 goto error0;
611         }
612
613         status = acpi_load_tables();
614         if (ACPI_FAILURE(status)) {
615                 printk(KERN_ERR PREFIX
616                        "Unable to load the System Description Tables\n");
617                 goto error0;
618         }
619
620 #ifdef CONFIG_X86
621         if (!acpi_ioapic) {
622                 extern u8 acpi_sci_flags;
623
624                 /* compatible (0) means level (3) */
625                 if (!(acpi_sci_flags & ACPI_MADT_TRIGGER_MASK)) {
626                         acpi_sci_flags &= ~ACPI_MADT_TRIGGER_MASK;
627                         acpi_sci_flags |= ACPI_MADT_TRIGGER_LEVEL;
628                 }
629                 /* Set PIC-mode SCI trigger type */
630                 acpi_pic_sci_set_trigger(acpi_gbl_FADT.sci_interrupt,
631                                          (acpi_sci_flags & ACPI_MADT_TRIGGER_MASK) >> 2);
632         } else {
633                 extern int acpi_sci_override_gsi;
634                 /*
635                  * now that acpi_gbl_FADT is initialized,
636                  * update it with result from INT_SRC_OVR parsing
637                  */
638                 acpi_gbl_FADT.sci_interrupt = acpi_sci_override_gsi;
639         }
640 #endif
641
642         status =
643             acpi_enable_subsystem(~
644                                   (ACPI_NO_HARDWARE_INIT |
645                                    ACPI_NO_ACPI_ENABLE));
646         if (ACPI_FAILURE(status)) {
647                 printk(KERN_ERR PREFIX "Unable to enable ACPI\n");
648                 goto error0;
649         }
650
651         return;
652
653       error0:
654         disable_acpi();
655         return;
656 }
657
658 static int __init acpi_bus_init(void)
659 {
660         int result = 0;
661         acpi_status status = AE_OK;
662         extern acpi_status acpi_os_initialize1(void);
663
664
665         status = acpi_os_initialize1();
666
667         status =
668             acpi_enable_subsystem(ACPI_NO_HARDWARE_INIT | ACPI_NO_ACPI_ENABLE);
669         if (ACPI_FAILURE(status)) {
670                 printk(KERN_ERR PREFIX
671                        "Unable to start the ACPI Interpreter\n");
672                 goto error1;
673         }
674
675         if (ACPI_FAILURE(status)) {
676                 printk(KERN_ERR PREFIX
677                        "Unable to initialize ACPI OS objects\n");
678                 goto error1;
679         }
680 #ifdef CONFIG_ACPI_EC
681         /*
682          * ACPI 2.0 requires the EC driver to be loaded and work before
683          * the EC device is found in the namespace (i.e. before acpi_initialize_objects()
684          * is called).
685          *
686          * This is accomplished by looking for the ECDT table, and getting 
687          * the EC parameters out of that.
688          */
689         status = acpi_ec_ecdt_probe();
690         /* Ignore result. Not having an ECDT is not fatal. */
691 #endif
692
693         status = acpi_initialize_objects(ACPI_FULL_INITIALIZATION);
694         if (ACPI_FAILURE(status)) {
695                 printk(KERN_ERR PREFIX "Unable to initialize ACPI objects\n");
696                 goto error1;
697         }
698
699         printk(KERN_INFO PREFIX "Interpreter enabled\n");
700
701         /*
702          * Get the system interrupt model and evaluate \_PIC.
703          */
704         result = acpi_bus_init_irq();
705         if (result)
706                 goto error1;
707
708         /*
709          * Register the for all standard device notifications.
710          */
711         status =
712             acpi_install_notify_handler(ACPI_ROOT_OBJECT, ACPI_SYSTEM_NOTIFY,
713                                         &acpi_bus_notify, NULL);
714         if (ACPI_FAILURE(status)) {
715                 printk(KERN_ERR PREFIX
716                        "Unable to register for device notifications\n");
717                 goto error1;
718         }
719
720         /*
721          * Create the top ACPI proc directory
722          */
723         acpi_root_dir = proc_mkdir(ACPI_BUS_FILE_ROOT, NULL);
724
725         return 0;
726
727         /* Mimic structured exception handling */
728       error1:
729         acpi_terminate();
730         return -ENODEV;
731 }
732
733 decl_subsys(acpi, NULL, NULL);
734
735 static int __init acpi_init(void)
736 {
737         int result = 0;
738
739
740         if (acpi_disabled) {
741                 printk(KERN_INFO PREFIX "Interpreter disabled.\n");
742                 return -ENODEV;
743         }
744
745         result = firmware_register(&acpi_subsys);
746         if (result < 0)
747                 printk(KERN_WARNING "%s: firmware_register error: %d\n",
748                         __FUNCTION__, result);
749
750         result = acpi_bus_init();
751
752         if (!result) {
753 #ifdef CONFIG_PM_LEGACY
754                 if (!PM_IS_ACTIVE())
755                         pm_active = 1;
756                 else {
757                         printk(KERN_INFO PREFIX
758                                "APM is already active, exiting\n");
759                         disable_acpi();
760                         result = -ENODEV;
761                 }
762 #endif
763         } else
764                 disable_acpi();
765
766         return result;
767 }
768
769 subsys_initcall(acpi_init);