bus.c revision af4f949c6b4ffa5119aad980626e5b04daca961b 
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/list.h>
29#include <linux/sched.h>
30#include <linux/pm.h>
31#include <linux/pm_legacy.h>
32#include <linux/device.h>
33#include <linux/proc_fs.h>
34#ifdef CONFIG_X86
35#include <asm/mpspec.h>
36#endif
37#include <acpi/acpi_bus.h>
38#include <acpi/acpi_drivers.h>
39
40#define _COMPONENT		ACPI_BUS_COMPONENT
41ACPI_MODULE_NAME("acpi_bus")
42#ifdef	CONFIG_X86
43extern void __init acpi_pic_sci_set_trigger(unsigned int irq, u16 trigger);
44#endif
45
46struct fadt_descriptor acpi_fadt;
47EXPORT_SYMBOL(acpi_fadt);
48
49struct acpi_device *acpi_root;
50struct proc_dir_entry *acpi_root_dir;
51EXPORT_SYMBOL(acpi_root_dir);
52
53#define STRUCT_TO_INT(s)	(*((int*)&s))
54
55/* --------------------------------------------------------------------------
56                                Device Management
57   -------------------------------------------------------------------------- */
58
59int acpi_bus_get_device(acpi_handle handle, struct acpi_device **device)
60{
61	acpi_status status = AE_OK;
62
63
64	if (!device)
65		return -EINVAL;
66
67	/* TBD: Support fixed-feature devices */
68
69	status = acpi_get_data(handle, acpi_bus_data_handler, (void **)device);
70	if (ACPI_FAILURE(status) || !*device) {
71		ACPI_EXCEPTION((AE_INFO, status, "No context for object [%p]", handle));
72		return -ENODEV;
73	}
74
75	return 0;
76}
77
78EXPORT_SYMBOL(acpi_bus_get_device);
79
80int acpi_bus_get_status(struct acpi_device *device)
81{
82	acpi_status status = AE_OK;
83	unsigned long sta = 0;
84
85
86	if (!device)
87		return -EINVAL;
88
89	/*
90	 * Evaluate _STA if present.
91	 */
92	if (device->flags.dynamic_status) {
93		status =
94		    acpi_evaluate_integer(device->handle, "_STA", NULL, &sta);
95		if (ACPI_FAILURE(status))
96			return -ENODEV;
97		STRUCT_TO_INT(device->status) = (int)sta;
98	}
99
100	/*
101	 * Otherwise we assume the status of our parent (unless we don't
102	 * have one, in which case status is implied).
103	 */
104	else if (device->parent)
105		device->status = device->parent->status;
106	else
107		STRUCT_TO_INT(device->status) = 0x0F;
108
109	if (device->status.functional && !device->status.present) {
110		printk(KERN_WARNING PREFIX "Device [%s] status [%08x]: "
111		       "functional but not present; setting present\n",
112		       device->pnp.bus_id, (u32) STRUCT_TO_INT(device->status));
113		device->status.present = 1;
114	}
115
116	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]\n",
117			  device->pnp.bus_id,
118			  (u32) STRUCT_TO_INT(device->status)));
119
120	return 0;
121}
122
123EXPORT_SYMBOL(acpi_bus_get_status);
124
125/* --------------------------------------------------------------------------
126                                 Power Management
127   -------------------------------------------------------------------------- */
128
129int acpi_bus_get_power(acpi_handle handle, 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
137	result = acpi_bus_get_device(handle, &device);
138	if (result)
139		return result;
140
141	*state = ACPI_STATE_UNKNOWN;
142
143	if (!device->flags.power_manageable) {
144		/* TBD: Non-recursive algorithm for walking up hierarchy */
145		if (device->parent)
146			*state = device->parent->power.state;
147		else
148			*state = ACPI_STATE_D0;
149	} else {
150		/*
151		 * Get the device's power state either directly (via _PSC) or
152		 * indirectly (via power resources).
153		 */
154		if (device->power.flags.explicit_get) {
155			status = acpi_evaluate_integer(device->handle, "_PSC",
156						       NULL, &psc);
157			if (ACPI_FAILURE(status))
158				return -ENODEV;
159			device->power.state = (int)psc;
160		} else if (device->power.flags.power_resources) {
161			result = acpi_power_get_inferred_state(device);
162			if (result)
163				return result;
164		}
165
166		*state = device->power.state;
167	}
168
169	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] power state is D%d\n",
170			  device->pnp.bus_id, device->power.state));
171
172	return 0;
173}
174
175EXPORT_SYMBOL(acpi_bus_get_power);
176
177int acpi_bus_set_power(acpi_handle handle, int state)
178{
179	int result = 0;
180	acpi_status status = AE_OK;
181	struct acpi_device *device = NULL;
182	char object_name[5] = { '_', 'P', 'S', '0' + state, '\0' };
183
184
185	result = acpi_bus_get_device(handle, &device);
186	if (result)
187		return result;
188
189	if ((state < ACPI_STATE_D0) || (state > ACPI_STATE_D3))
190		return -EINVAL;
191
192	/* Make sure this is a valid target state */
193
194	if (!device->flags.power_manageable) {
195		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device `[%s]' is not power manageable",
196				device->kobj.name));
197		return -ENODEV;
198	}
199	/*
200	 * Get device's current power state if it's unknown
201	 * This means device power state isn't initialized or previous setting failed
202	 */
203	if (!device->flags.force_power_state) {
204		if (device->power.state == ACPI_STATE_UNKNOWN)
205			acpi_bus_get_power(device->handle, &device->power.state);
206		if (state == device->power.state) {
207			ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device is already at D%d\n",
208					  state));
209			return 0;
210		}
211	}
212	if (!device->power.states[state].flags.valid) {
213		printk(KERN_WARNING PREFIX "Device does not support D%d\n", state);
214		return -ENODEV;
215	}
216	if (device->parent && (state < device->parent->power.state)) {
217		printk(KERN_WARNING PREFIX
218			      "Cannot set device to a higher-powered"
219			      " state than parent\n");
220		return -ENODEV;
221	}
222
223	/*
224	 * Transition Power
225	 * ----------------
226	 * On transitions to a high-powered state we first apply power (via
227	 * power resources) then evalute _PSx.  Conversly for transitions to
228	 * a lower-powered state.
229	 */
230	if (state < device->power.state) {
231		if (device->power.flags.power_resources) {
232			result = acpi_power_transition(device, state);
233			if (result)
234				goto end;
235		}
236		if (device->power.states[state].flags.explicit_set) {
237			status = acpi_evaluate_object(device->handle,
238						      object_name, NULL, NULL);
239			if (ACPI_FAILURE(status)) {
240				result = -ENODEV;
241				goto end;
242			}
243		}
244	} else {
245		if (device->power.states[state].flags.explicit_set) {
246			status = acpi_evaluate_object(device->handle,
247						      object_name, NULL, NULL);
248			if (ACPI_FAILURE(status)) {
249				result = -ENODEV;
250				goto end;
251			}
252		}
253		if (device->power.flags.power_resources) {
254			result = acpi_power_transition(device, state);
255			if (result)
256				goto end;
257		}
258	}
259
260      end:
261	if (result)
262		printk(KERN_WARNING PREFIX
263			      "Transitioning device [%s] to D%d\n",
264			      device->pnp.bus_id, state);
265	else
266		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
267				  "Device [%s] transitioned to D%d\n",
268				  device->pnp.bus_id, state));
269
270	return result;
271}
272
273EXPORT_SYMBOL(acpi_bus_set_power);
274
275/* --------------------------------------------------------------------------
276                                Event Management
277   -------------------------------------------------------------------------- */
278
279static DEFINE_SPINLOCK(acpi_bus_event_lock);
280
281LIST_HEAD(acpi_bus_event_list);
282DECLARE_WAIT_QUEUE_HEAD(acpi_bus_event_queue);
283
284extern int event_is_open;
285
286int acpi_bus_generate_event(struct acpi_device *device, u8 type, int data)
287{
288	struct acpi_bus_event *event = NULL;
289	unsigned long flags = 0;
290
291
292	if (!device)
293		return -EINVAL;
294
295	/* drop event on the floor if no one's listening */
296	if (!event_is_open)
297		return 0;
298
299	event = kmalloc(sizeof(struct acpi_bus_event), GFP_ATOMIC);
300	if (!event)
301		return -ENOMEM;
302
303	strcpy(event->device_class, device->pnp.device_class);
304	strcpy(event->bus_id, device->pnp.bus_id);
305	event->type = type;
306	event->data = data;
307
308	spin_lock_irqsave(&acpi_bus_event_lock, flags);
309	list_add_tail(&event->node, &acpi_bus_event_list);
310	spin_unlock_irqrestore(&acpi_bus_event_lock, flags);
311
312	wake_up_interruptible(&acpi_bus_event_queue);
313
314	return 0;
315}
316
317EXPORT_SYMBOL(acpi_bus_generate_event);
318
319int acpi_bus_receive_event(struct acpi_bus_event *event)
320{
321	unsigned long flags = 0;
322	struct acpi_bus_event *entry = NULL;
323
324	DECLARE_WAITQUEUE(wait, current);
325
326
327	if (!event)
328		return -EINVAL;
329
330	if (list_empty(&acpi_bus_event_list)) {
331
332		set_current_state(TASK_INTERRUPTIBLE);
333		add_wait_queue(&acpi_bus_event_queue, &wait);
334
335		if (list_empty(&acpi_bus_event_list))
336			schedule();
337
338		remove_wait_queue(&acpi_bus_event_queue, &wait);
339		set_current_state(TASK_RUNNING);
340
341		if (signal_pending(current))
342			return -ERESTARTSYS;
343	}
344
345	spin_lock_irqsave(&acpi_bus_event_lock, flags);
346	entry =
347	    list_entry(acpi_bus_event_list.next, struct acpi_bus_event, node);
348	if (entry)
349		list_del(&entry->node);
350	spin_unlock_irqrestore(&acpi_bus_event_lock, flags);
351
352	if (!entry)
353		return -ENODEV;
354
355	memcpy(event, entry, sizeof(struct acpi_bus_event));
356
357	kfree(entry);
358
359	return 0;
360}
361
362EXPORT_SYMBOL(acpi_bus_receive_event);
363
364/* --------------------------------------------------------------------------
365                             Notification Handling
366   -------------------------------------------------------------------------- */
367
368static int
369acpi_bus_check_device(struct acpi_device *device, int *status_changed)
370{
371	acpi_status status = 0;
372	struct acpi_device_status old_status;
373
374
375	if (!device)
376		return -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 0;
394	}
395
396	status = acpi_bus_get_status(device);
397	if (ACPI_FAILURE(status))
398		return -ENODEV;
399
400	if (STRUCT_TO_INT(old_status) == STRUCT_TO_INT(device->status))
401		return 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	} else if (!(device->status.present) && (old_status.present)) {
413		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device removal detected\n"));
414		/* TBD: Handle device removal */
415	}
416
417	return 0;
418}
419
420static int acpi_bus_check_scope(struct acpi_device *device)
421{
422	int result = 0;
423	int status_changed = 0;
424
425
426	if (!device)
427		return -EINVAL;
428
429	/* Status Change? */
430	result = acpi_bus_check_device(device, &status_changed);
431	if (result)
432		return result;
433
434	if (!status_changed)
435		return 0;
436
437	/*
438	 * TBD: Enumerate child devices within this device's scope and
439	 *       run acpi_bus_check_device()'s on them.
440	 */
441
442	return 0;
443}
444
445/**
446 * acpi_bus_notify
447 * ---------------
448 * Callback for all 'system-level' device notifications (values 0x00-0x7F).
449 */
450static void acpi_bus_notify(acpi_handle handle, u32 type, void *data)
451{
452	int result = 0;
453	struct acpi_device *device = NULL;
454
455
456	if (acpi_bus_get_device(handle, &device))
457		return;
458
459	switch (type) {
460
461	case ACPI_NOTIFY_BUS_CHECK:
462		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
463				  "Received BUS CHECK notification for device [%s]\n",
464				  device->pnp.bus_id));
465		result = acpi_bus_check_scope(device);
466		/*
467		 * TBD: We'll need to outsource certain events to non-ACPI
468		 *      drivers via the device manager (device.c).
469		 */
470		break;
471
472	case ACPI_NOTIFY_DEVICE_CHECK:
473		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
474				  "Received DEVICE CHECK notification for device [%s]\n",
475				  device->pnp.bus_id));
476		result = acpi_bus_check_device(device, NULL);
477		/*
478		 * TBD: We'll need to outsource certain events to non-ACPI
479		 *      drivers via the device manager (device.c).
480		 */
481		break;
482
483	case ACPI_NOTIFY_DEVICE_WAKE:
484		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
485				  "Received DEVICE WAKE notification for device [%s]\n",
486				  device->pnp.bus_id));
487		/* TBD */
488		break;
489
490	case ACPI_NOTIFY_EJECT_REQUEST:
491		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
492				  "Received EJECT REQUEST notification for device [%s]\n",
493				  device->pnp.bus_id));
494		/* TBD */
495		break;
496
497	case ACPI_NOTIFY_DEVICE_CHECK_LIGHT:
498		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
499				  "Received DEVICE CHECK LIGHT notification for device [%s]\n",
500				  device->pnp.bus_id));
501		/* TBD: Exactly what does 'light' mean? */
502		break;
503
504	case ACPI_NOTIFY_FREQUENCY_MISMATCH:
505		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
506				  "Received FREQUENCY MISMATCH notification for device [%s]\n",
507				  device->pnp.bus_id));
508		/* TBD */
509		break;
510
511	case ACPI_NOTIFY_BUS_MODE_MISMATCH:
512		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
513				  "Received BUS MODE MISMATCH notification for device [%s]\n",
514				  device->pnp.bus_id));
515		/* TBD */
516		break;
517
518	case ACPI_NOTIFY_POWER_FAULT:
519		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
520				  "Received POWER FAULT notification for device [%s]\n",
521				  device->pnp.bus_id));
522		/* TBD */
523		break;
524
525	default:
526		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
527				  "Received unknown/unsupported notification [%08x]\n",
528				  type));
529		break;
530	}
531
532	return;
533}
534
535/* --------------------------------------------------------------------------
536                             Initialization/Cleanup
537   -------------------------------------------------------------------------- */
538
539static int __init acpi_bus_init_irq(void)
540{
541	acpi_status status = AE_OK;
542	union acpi_object arg = { ACPI_TYPE_INTEGER };
543	struct acpi_object_list arg_list = { 1, &arg };
544	char *message = NULL;
545
546
547	/*
548	 * Let the system know what interrupt model we are using by
549	 * evaluating the \_PIC object, if exists.
550	 */
551
552	switch (acpi_irq_model) {
553	case ACPI_IRQ_MODEL_PIC:
554		message = "PIC";
555		break;
556	case ACPI_IRQ_MODEL_IOAPIC:
557		message = "IOAPIC";
558		break;
559	case ACPI_IRQ_MODEL_IOSAPIC:
560		message = "IOSAPIC";
561		break;
562	default:
563		printk(KERN_WARNING PREFIX "Unknown interrupt routing model\n");
564		return -ENODEV;
565	}
566
567	printk(KERN_INFO PREFIX "Using %s for interrupt routing\n", message);
568
569	arg.integer.value = acpi_irq_model;
570
571	status = acpi_evaluate_object(NULL, "\\_PIC", &arg_list, NULL);
572	if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
573		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PIC"));
574		return -ENODEV;
575	}
576
577	return 0;
578}
579
580void __init acpi_early_init(void)
581{
582	acpi_status status = AE_OK;
583	struct acpi_buffer buffer = { sizeof(acpi_fadt), &acpi_fadt };
584
585
586	if (acpi_disabled)
587		return;
588
589	printk(KERN_INFO PREFIX "Core revision %08x\n", ACPI_CA_VERSION);
590
591	/* enable workarounds, unless strict ACPI spec. compliance */
592	if (!acpi_strict)
593		acpi_gbl_enable_interpreter_slack = TRUE;
594
595	status = acpi_initialize_subsystem();
596	if (ACPI_FAILURE(status)) {
597		printk(KERN_ERR PREFIX
598		       "Unable to initialize the ACPI Interpreter\n");
599		goto error0;
600	}
601
602	status = acpi_load_tables();
603	if (ACPI_FAILURE(status)) {
604		printk(KERN_ERR PREFIX
605		       "Unable to load the System Description Tables\n");
606		goto error0;
607	}
608
609	/*
610	 * Get a separate copy of the FADT for use by other drivers.
611	 */
612	status = acpi_get_table(ACPI_TABLE_ID_FADT, 1, &buffer);
613	if (ACPI_FAILURE(status)) {
614		printk(KERN_ERR PREFIX "Unable to get the FADT\n");
615		goto error0;
616	}
617#ifdef CONFIG_X86
618	if (!acpi_ioapic) {
619		extern acpi_interrupt_flags acpi_sci_flags;
620
621		/* compatible (0) means level (3) */
622		if (acpi_sci_flags.trigger == 0)
623			acpi_sci_flags.trigger = 3;
624
625		/* Set PIC-mode SCI trigger type */
626		acpi_pic_sci_set_trigger(acpi_fadt.sci_int,
627					 acpi_sci_flags.trigger);
628	} else {
629		extern int acpi_sci_override_gsi;
630		/*
631		 * now that acpi_fadt is initialized,
632		 * update it with result from INT_SRC_OVR parsing
633		 */
634		acpi_fadt.sci_int = acpi_sci_override_gsi;
635	}
636#endif
637
638	status =
639	    acpi_enable_subsystem(~
640				  (ACPI_NO_HARDWARE_INIT |
641				   ACPI_NO_ACPI_ENABLE));
642	if (ACPI_FAILURE(status)) {
643		printk(KERN_ERR PREFIX "Unable to enable ACPI\n");
644		goto error0;
645	}
646
647	return;
648
649      error0:
650	disable_acpi();
651	return;
652}
653
654static int __init acpi_bus_init(void)
655{
656	int result = 0;
657	acpi_status status = AE_OK;
658	extern acpi_status acpi_os_initialize1(void);
659
660
661	status = acpi_os_initialize1();
662
663	status =
664	    acpi_enable_subsystem(ACPI_NO_HARDWARE_INIT | ACPI_NO_ACPI_ENABLE);
665	if (ACPI_FAILURE(status)) {
666		printk(KERN_ERR PREFIX
667		       "Unable to start the ACPI Interpreter\n");
668		goto error1;
669	}
670
671	if (ACPI_FAILURE(status)) {
672		printk(KERN_ERR PREFIX
673		       "Unable to initialize ACPI OS objects\n");
674		goto error1;
675	}
676#ifdef CONFIG_ACPI_EC
677	/*
678	 * ACPI 2.0 requires the EC driver to be loaded and work before
679	 * the EC device is found in the namespace (i.e. before acpi_initialize_objects()
680	 * is called).
681	 *
682	 * This is accomplished by looking for the ECDT table, and getting
683	 * the EC parameters out of that.
684	 */
685	status = acpi_ec_ecdt_probe();
686	/* Ignore result. Not having an ECDT is not fatal. */
687#endif
688
689	status = acpi_initialize_objects(ACPI_FULL_INITIALIZATION);
690	if (ACPI_FAILURE(status)) {
691		printk(KERN_ERR PREFIX "Unable to initialize ACPI objects\n");
692		goto error1;
693	}
694
695	printk(KERN_INFO PREFIX "Interpreter enabled\n");
696
697	/*
698	 * Get the system interrupt model and evaluate \_PIC.
699	 */
700	result = acpi_bus_init_irq();
701	if (result)
702		goto error1;
703
704	/*
705	 * Register the for all standard device notifications.
706	 */
707	status =
708	    acpi_install_notify_handler(ACPI_ROOT_OBJECT, ACPI_SYSTEM_NOTIFY,
709					&acpi_bus_notify, NULL);
710	if (ACPI_FAILURE(status)) {
711		printk(KERN_ERR PREFIX
712		       "Unable to register for device notifications\n");
713		goto error1;
714	}
715
716	/*
717	 * Create the top ACPI proc directory
718	 */
719	acpi_root_dir = proc_mkdir(ACPI_BUS_FILE_ROOT, NULL);
720
721	return 0;
722
723	/* Mimic structured exception handling */
724      error1:
725	acpi_terminate();
726	return -ENODEV;
727}
728
729decl_subsys(acpi, NULL, NULL);
730
731static int __init acpi_init(void)
732{
733	int result = 0;
734
735
736	if (acpi_disabled) {
737		printk(KERN_INFO PREFIX "Interpreter disabled.\n");
738		return -ENODEV;
739	}
740
741	firmware_register(&acpi_subsys);
742
743	result = acpi_bus_init();
744
745	if (!result) {
746#ifdef CONFIG_PM_LEGACY
747		if (!PM_IS_ACTIVE())
748			pm_active = 1;
749		else {
750			printk(KERN_INFO PREFIX
751			       "APM is already active, exiting\n");
752			disable_acpi();
753			result = -ENODEV;
754		}
755#endif
756	} else
757		disable_acpi();
758
759	return result;
760}
761
762subsys_initcall(acpi_init);
763