bus.c revision c35923bc558074d4f5e6f9706e4cb9811ae55775 
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
42ACPI_MODULE_NAME("bus");
43#ifdef	CONFIG_X86
44extern void __init acpi_pic_sci_set_trigger(unsigned int irq, u16 trigger);
45#endif
46
47struct acpi_device *acpi_root;
48struct proc_dir_entry *acpi_root_dir;
49EXPORT_SYMBOL(acpi_root_dir);
50
51#define STRUCT_TO_INT(s)	(*((int*)&s))
52
53/* --------------------------------------------------------------------------
54                                Device Management
55   -------------------------------------------------------------------------- */
56
57int 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
77EXPORT_SYMBOL(acpi_bus_get_device);
78
79int 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) =
107		    ACPI_STA_DEVICE_PRESENT | ACPI_STA_DEVICE_ENABLED |
108		    ACPI_STA_DEVICE_UI      | ACPI_STA_DEVICE_FUNCTIONING;
109
110	if (device->status.functional && !device->status.present) {
111		printk(KERN_WARNING PREFIX "Device [%s] status [%08x]: "
112		       "functional but not present; setting present\n",
113		       device->pnp.bus_id, (u32) STRUCT_TO_INT(device->status));
114		device->status.present = 1;
115	}
116
117	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]\n",
118			  device->pnp.bus_id,
119			  (u32) STRUCT_TO_INT(device->status)));
120
121	return 0;
122}
123
124EXPORT_SYMBOL(acpi_bus_get_status);
125
126/* --------------------------------------------------------------------------
127                                 Power Management
128   -------------------------------------------------------------------------- */
129
130int acpi_bus_get_power(acpi_handle handle, int *state)
131{
132	int result = 0;
133	acpi_status status = 0;
134	struct acpi_device *device = NULL;
135	unsigned long psc = 0;
136
137
138	result = acpi_bus_get_device(handle, &device);
139	if (result)
140		return 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	} else {
151		/*
152		 * Get the device's power state either directly (via _PSC) or
153		 * indirectly (via power resources).
154		 */
155		if (device->power.flags.explicit_get) {
156			status = acpi_evaluate_integer(device->handle, "_PSC",
157						       NULL, &psc);
158			if (ACPI_FAILURE(status))
159				return -ENODEV;
160			device->power.state = (int)psc;
161		} else if (device->power.flags.power_resources) {
162			result = acpi_power_get_inferred_state(device);
163			if (result)
164				return result;
165		}
166
167		*state = device->power.state;
168	}
169
170	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] power state is D%d\n",
171			  device->pnp.bus_id, device->power.state));
172
173	return 0;
174}
175
176EXPORT_SYMBOL(acpi_bus_get_power);
177
178int acpi_bus_set_power(acpi_handle handle, int state)
179{
180	int result = 0;
181	acpi_status status = AE_OK;
182	struct acpi_device *device = NULL;
183	char object_name[5] = { '_', 'P', 'S', '0' + state, '\0' };
184
185
186	result = acpi_bus_get_device(handle, &device);
187	if (result)
188		return result;
189
190	if ((state < ACPI_STATE_D0) || (state > ACPI_STATE_D3))
191		return -EINVAL;
192
193	/* Make sure this is a valid target state */
194
195	if (!device->flags.power_manageable) {
196		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device `[%s]' is not power manageable\n",
197				kobject_name(&device->dev.kobj)));
198		return -ENODEV;
199	}
200	/*
201	 * Get device's current power state
202	 */
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		device->power.state = state;
265		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
266				  "Device [%s] transitioned to D%d\n",
267				  device->pnp.bus_id, state));
268	}
269
270	return result;
271}
272
273EXPORT_SYMBOL(acpi_bus_set_power);
274
275/* --------------------------------------------------------------------------
276                                Event Management
277   -------------------------------------------------------------------------- */
278
279#ifdef CONFIG_ACPI_PROC_EVENT
280static DEFINE_SPINLOCK(acpi_bus_event_lock);
281
282LIST_HEAD(acpi_bus_event_list);
283DECLARE_WAIT_QUEUE_HEAD(acpi_bus_event_queue);
284
285extern int event_is_open;
286
287int acpi_bus_generate_proc_event4(const char *device_class, const char *bus_id, u8 type, int data)
288{
289	struct acpi_bus_event *event;
290	unsigned long flags = 0;
291
292	/* drop event on the floor if no one's listening */
293	if (!event_is_open)
294		return 0;
295
296	event = kmalloc(sizeof(struct acpi_bus_event), GFP_ATOMIC);
297	if (!event)
298		return -ENOMEM;
299
300	strcpy(event->device_class, device_class);
301	strcpy(event->bus_id, bus_id);
302	event->type = type;
303	event->data = data;
304
305	spin_lock_irqsave(&acpi_bus_event_lock, flags);
306	list_add_tail(&event->node, &acpi_bus_event_list);
307	spin_unlock_irqrestore(&acpi_bus_event_lock, flags);
308
309	wake_up_interruptible(&acpi_bus_event_queue);
310
311	return 0;
312
313}
314
315EXPORT_SYMBOL_GPL(acpi_bus_generate_proc_event4);
316
317int acpi_bus_generate_proc_event(struct acpi_device *device, u8 type, int data)
318{
319	if (!device)
320		return -EINVAL;
321	return acpi_bus_generate_proc_event4(device->pnp.device_class,
322					     device->pnp.bus_id, type, data);
323}
324
325EXPORT_SYMBOL(acpi_bus_generate_proc_event);
326
327int acpi_bus_receive_event(struct acpi_bus_event *event)
328{
329	unsigned long flags = 0;
330	struct acpi_bus_event *entry = NULL;
331
332	DECLARE_WAITQUEUE(wait, current);
333
334
335	if (!event)
336		return -EINVAL;
337
338	if (list_empty(&acpi_bus_event_list)) {
339
340		set_current_state(TASK_INTERRUPTIBLE);
341		add_wait_queue(&acpi_bus_event_queue, &wait);
342
343		if (list_empty(&acpi_bus_event_list))
344			schedule();
345
346		remove_wait_queue(&acpi_bus_event_queue, &wait);
347		set_current_state(TASK_RUNNING);
348
349		if (signal_pending(current))
350			return -ERESTARTSYS;
351	}
352
353	spin_lock_irqsave(&acpi_bus_event_lock, flags);
354	entry =
355	    list_entry(acpi_bus_event_list.next, struct acpi_bus_event, node);
356	if (entry)
357		list_del(&entry->node);
358	spin_unlock_irqrestore(&acpi_bus_event_lock, flags);
359
360	if (!entry)
361		return -ENODEV;
362
363	memcpy(event, entry, sizeof(struct acpi_bus_event));
364
365	kfree(entry);
366
367	return 0;
368}
369
370EXPORT_SYMBOL(acpi_bus_receive_event);
371#endif	/* CONFIG_ACPI_PROC_EVENT */
372
373/* --------------------------------------------------------------------------
374                             Notification Handling
375   -------------------------------------------------------------------------- */
376
377static int
378acpi_bus_check_device(struct acpi_device *device, int *status_changed)
379{
380	acpi_status status = 0;
381	struct acpi_device_status old_status;
382
383
384	if (!device)
385		return -EINVAL;
386
387	if (status_changed)
388		*status_changed = 0;
389
390	old_status = device->status;
391
392	/*
393	 * Make sure this device's parent is present before we go about
394	 * messing with the device.
395	 */
396	if (device->parent && !device->parent->status.present) {
397		device->status = device->parent->status;
398		if (STRUCT_TO_INT(old_status) != STRUCT_TO_INT(device->status)) {
399			if (status_changed)
400				*status_changed = 1;
401		}
402		return 0;
403	}
404
405	status = acpi_bus_get_status(device);
406	if (ACPI_FAILURE(status))
407		return -ENODEV;
408
409	if (STRUCT_TO_INT(old_status) == STRUCT_TO_INT(device->status))
410		return 0;
411
412	if (status_changed)
413		*status_changed = 1;
414
415	/*
416	 * Device Insertion/Removal
417	 */
418	if ((device->status.present) && !(old_status.present)) {
419		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device insertion detected\n"));
420		/* TBD: Handle device insertion */
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 0;
427}
428
429static int acpi_bus_check_scope(struct acpi_device *device)
430{
431	int result = 0;
432	int status_changed = 0;
433
434
435	if (!device)
436		return -EINVAL;
437
438	/* Status Change? */
439	result = acpi_bus_check_device(device, &status_changed);
440	if (result)
441		return result;
442
443	if (!status_changed)
444		return 0;
445
446	/*
447	 * TBD: Enumerate child devices within this device's scope and
448	 *       run acpi_bus_check_device()'s on them.
449	 */
450
451	return 0;
452}
453
454/**
455 * acpi_bus_notify
456 * ---------------
457 * Callback for all 'system-level' device notifications (values 0x00-0x7F).
458 */
459static void acpi_bus_notify(acpi_handle handle, u32 type, void *data)
460{
461	int result = 0;
462	struct acpi_device *device = NULL;
463
464
465	if (acpi_bus_get_device(handle, &device))
466		return;
467
468	switch (type) {
469
470	case ACPI_NOTIFY_BUS_CHECK:
471		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
472				  "Received BUS CHECK notification for device [%s]\n",
473				  device->pnp.bus_id));
474		result = acpi_bus_check_scope(device);
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_CHECK:
482		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
483				  "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,
494				  "Received DEVICE WAKE notification for device [%s]\n",
495				  device->pnp.bus_id));
496		/* TBD */
497		break;
498
499	case ACPI_NOTIFY_EJECT_REQUEST:
500		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
501				  "Received EJECT REQUEST notification for device [%s]\n",
502				  device->pnp.bus_id));
503		/* TBD */
504		break;
505
506	case ACPI_NOTIFY_DEVICE_CHECK_LIGHT:
507		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
508				  "Received DEVICE CHECK LIGHT notification for device [%s]\n",
509				  device->pnp.bus_id));
510		/* TBD: Exactly what does 'light' mean? */
511		break;
512
513	case ACPI_NOTIFY_FREQUENCY_MISMATCH:
514		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
515				  "Received FREQUENCY MISMATCH notification for device [%s]\n",
516				  device->pnp.bus_id));
517		/* TBD */
518		break;
519
520	case ACPI_NOTIFY_BUS_MODE_MISMATCH:
521		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
522				  "Received BUS MODE MISMATCH notification for device [%s]\n",
523				  device->pnp.bus_id));
524		/* TBD */
525		break;
526
527	case ACPI_NOTIFY_POWER_FAULT:
528		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
529				  "Received POWER FAULT notification for device [%s]\n",
530				  device->pnp.bus_id));
531		/* TBD */
532		break;
533
534	default:
535		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
536				  "Received unknown/unsupported notification [%08x]\n",
537				  type));
538		break;
539	}
540
541	return;
542}
543
544/* --------------------------------------------------------------------------
545                             Initialization/Cleanup
546   -------------------------------------------------------------------------- */
547
548static int __init acpi_bus_init_irq(void)
549{
550	acpi_status status = AE_OK;
551	union acpi_object arg = { ACPI_TYPE_INTEGER };
552	struct acpi_object_list arg_list = { 1, &arg };
553	char *message = NULL;
554
555
556	/*
557	 * Let the system know what interrupt model we are using by
558	 * evaluating the \_PIC object, if exists.
559	 */
560
561	switch (acpi_irq_model) {
562	case ACPI_IRQ_MODEL_PIC:
563		message = "PIC";
564		break;
565	case ACPI_IRQ_MODEL_IOAPIC:
566		message = "IOAPIC";
567		break;
568	case ACPI_IRQ_MODEL_IOSAPIC:
569		message = "IOSAPIC";
570		break;
571	case ACPI_IRQ_MODEL_PLATFORM:
572		message = "platform specific model";
573		break;
574	default:
575		printk(KERN_WARNING PREFIX "Unknown interrupt routing model\n");
576		return -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_EXCEPTION((AE_INFO, status, "Evaluating _PIC"));
586		return -ENODEV;
587	}
588
589	return 0;
590}
591
592acpi_native_uint acpi_gbl_permanent_mmap;
593
594
595void __init acpi_early_init(void)
596{
597	acpi_status status = AE_OK;
598
599	if (acpi_disabled)
600		return;
601
602	printk(KERN_INFO PREFIX "Core revision %08x\n", ACPI_CA_VERSION);
603
604	/* enable workarounds, unless strict ACPI spec. compliance */
605	if (!acpi_strict)
606		acpi_gbl_enable_interpreter_slack = TRUE;
607
608	acpi_gbl_permanent_mmap = 1;
609
610	status = acpi_reallocate_root_table();
611	if (ACPI_FAILURE(status)) {
612		printk(KERN_ERR PREFIX
613		       "Unable to reallocate ACPI tables\n");
614		goto error0;
615	}
616
617	status = acpi_initialize_subsystem();
618	if (ACPI_FAILURE(status)) {
619		printk(KERN_ERR PREFIX
620		       "Unable to initialize the ACPI Interpreter\n");
621		goto error0;
622	}
623
624	status = acpi_load_tables();
625	if (ACPI_FAILURE(status)) {
626		printk(KERN_ERR PREFIX
627		       "Unable to load the System Description Tables\n");
628		goto error0;
629	}
630
631#ifdef CONFIG_X86
632	if (!acpi_ioapic) {
633		extern u8 acpi_sci_flags;
634
635		/* compatible (0) means level (3) */
636		if (!(acpi_sci_flags & ACPI_MADT_TRIGGER_MASK)) {
637			acpi_sci_flags &= ~ACPI_MADT_TRIGGER_MASK;
638			acpi_sci_flags |= ACPI_MADT_TRIGGER_LEVEL;
639		}
640		/* Set PIC-mode SCI trigger type */
641		acpi_pic_sci_set_trigger(acpi_gbl_FADT.sci_interrupt,
642					 (acpi_sci_flags & ACPI_MADT_TRIGGER_MASK) >> 2);
643	} else {
644		extern int acpi_sci_override_gsi;
645		/*
646		 * now that acpi_gbl_FADT is initialized,
647		 * update it with result from INT_SRC_OVR parsing
648		 */
649		acpi_gbl_FADT.sci_interrupt = acpi_sci_override_gsi;
650	}
651#endif
652
653	status =
654	    acpi_enable_subsystem(~
655				  (ACPI_NO_HARDWARE_INIT |
656				   ACPI_NO_ACPI_ENABLE));
657	if (ACPI_FAILURE(status)) {
658		printk(KERN_ERR PREFIX "Unable to enable ACPI\n");
659		goto error0;
660	}
661
662	return;
663
664      error0:
665	disable_acpi();
666	return;
667}
668
669static int __init acpi_bus_init(void)
670{
671	int result = 0;
672	acpi_status status = AE_OK;
673	extern acpi_status acpi_os_initialize1(void);
674
675
676	status = acpi_os_initialize1();
677
678	status =
679	    acpi_enable_subsystem(ACPI_NO_HARDWARE_INIT | ACPI_NO_ACPI_ENABLE);
680	if (ACPI_FAILURE(status)) {
681		printk(KERN_ERR PREFIX
682		       "Unable to start the ACPI Interpreter\n");
683		goto error1;
684	}
685
686	if (ACPI_FAILURE(status)) {
687		printk(KERN_ERR PREFIX
688		       "Unable to initialize ACPI OS objects\n");
689		goto error1;
690	}
691#ifdef CONFIG_ACPI_EC
692	/*
693	 * ACPI 2.0 requires the EC driver to be loaded and work before
694	 * the EC device is found in the namespace (i.e. before acpi_initialize_objects()
695	 * is called).
696	 *
697	 * This is accomplished by looking for the ECDT table, and getting
698	 * the EC parameters out of that.
699	 */
700	status = acpi_ec_ecdt_probe();
701	/* Ignore result. Not having an ECDT is not fatal. */
702#endif
703
704	status = acpi_initialize_objects(ACPI_FULL_INITIALIZATION);
705	if (ACPI_FAILURE(status)) {
706		printk(KERN_ERR PREFIX "Unable to initialize ACPI objects\n");
707		goto error1;
708	}
709
710	printk(KERN_INFO PREFIX "Interpreter enabled\n");
711
712	/* Initialize sleep structures */
713	acpi_sleep_init();
714
715	/*
716	 * Get the system interrupt model and evaluate \_PIC.
717	 */
718	result = acpi_bus_init_irq();
719	if (result)
720		goto error1;
721
722	/*
723	 * Register the for all standard device notifications.
724	 */
725	status =
726	    acpi_install_notify_handler(ACPI_ROOT_OBJECT, ACPI_SYSTEM_NOTIFY,
727					&acpi_bus_notify, NULL);
728	if (ACPI_FAILURE(status)) {
729		printk(KERN_ERR PREFIX
730		       "Unable to register for device notifications\n");
731		goto error1;
732	}
733
734	/*
735	 * Create the top ACPI proc directory
736	 */
737	acpi_root_dir = proc_mkdir(ACPI_BUS_FILE_ROOT, NULL);
738
739	return 0;
740
741	/* Mimic structured exception handling */
742      error1:
743	acpi_terminate();
744	return -ENODEV;
745}
746
747decl_subsys(acpi, NULL, NULL);
748
749static int __init acpi_init(void)
750{
751	int result = 0;
752
753
754	if (acpi_disabled) {
755		printk(KERN_INFO PREFIX "Interpreter disabled.\n");
756		return -ENODEV;
757	}
758
759	result = firmware_register(&acpi_subsys);
760	if (result < 0)
761		printk(KERN_WARNING "%s: firmware_register error: %d\n",
762			__FUNCTION__, result);
763
764	result = acpi_bus_init();
765
766	if (!result) {
767#ifdef CONFIG_PM_LEGACY
768		if (!PM_IS_ACTIVE())
769			pm_active = 1;
770		else {
771			printk(KERN_INFO PREFIX
772			       "APM is already active, exiting\n");
773			disable_acpi();
774			result = -ENODEV;
775		}
776#endif
777	} else
778		disable_acpi();
779
780	return result;
781}
782
783subsys_initcall(acpi_init);
784