xref: /linux/drivers/acpi/sleep.c (revision b233b28eac0cc37d07c2d007ea08c86c778c5af4)
1 /*
2  * sleep.c - ACPI sleep support.
3  *
4  * Copyright (c) 2005 Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
5  * Copyright (c) 2004 David Shaohua Li <shaohua.li@intel.com>
6  * Copyright (c) 2000-2003 Patrick Mochel
7  * Copyright (c) 2003 Open Source Development Lab
8  *
9  * This file is released under the GPLv2.
10  *
11  */
12 
13 #include <linux/delay.h>
14 #include <linux/irq.h>
15 #include <linux/dmi.h>
16 #include <linux/device.h>
17 #include <linux/suspend.h>
18 #include <linux/reboot.h>
19 
20 #include <asm/io.h>
21 
22 #include <acpi/acpi_bus.h>
23 #include <acpi/acpi_drivers.h>
24 #include "sleep.h"
25 
26 u8 sleep_states[ACPI_S_STATE_COUNT];
27 
28 static void acpi_sleep_tts_switch(u32 acpi_state)
29 {
30 	union acpi_object in_arg = { ACPI_TYPE_INTEGER };
31 	struct acpi_object_list arg_list = { 1, &in_arg };
32 	acpi_status status = AE_OK;
33 
34 	in_arg.integer.value = acpi_state;
35 	status = acpi_evaluate_object(NULL, "\\_TTS", &arg_list, NULL);
36 	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
37 		/*
38 		 * OS can't evaluate the _TTS object correctly. Some warning
39 		 * message will be printed. But it won't break anything.
40 		 */
41 		printk(KERN_NOTICE "Failure in evaluating _TTS object\n");
42 	}
43 }
44 
45 static int tts_notify_reboot(struct notifier_block *this,
46 			unsigned long code, void *x)
47 {
48 	acpi_sleep_tts_switch(ACPI_STATE_S5);
49 	return NOTIFY_DONE;
50 }
51 
52 static struct notifier_block tts_notifier = {
53 	.notifier_call	= tts_notify_reboot,
54 	.next		= NULL,
55 	.priority	= 0,
56 };
57 
58 static int acpi_sleep_prepare(u32 acpi_state)
59 {
60 #ifdef CONFIG_ACPI_SLEEP
61 	/* do we have a wakeup address for S2 and S3? */
62 	if (acpi_state == ACPI_STATE_S3) {
63 		if (!acpi_wakeup_address) {
64 			return -EFAULT;
65 		}
66 		acpi_set_firmware_waking_vector(
67 				(acpi_physical_address)acpi_wakeup_address);
68 
69 	}
70 	ACPI_FLUSH_CPU_CACHE();
71 	acpi_enable_wakeup_device_prep(acpi_state);
72 #endif
73 	printk(KERN_INFO PREFIX "Preparing to enter system sleep state S%d\n",
74 		acpi_state);
75 	acpi_enter_sleep_state_prep(acpi_state);
76 	return 0;
77 }
78 
79 #ifdef CONFIG_ACPI_SLEEP
80 static u32 acpi_target_sleep_state = ACPI_STATE_S0;
81 /*
82  * ACPI 1.0 wants us to execute _PTS before suspending devices, so we allow the
83  * user to request that behavior by using the 'acpi_old_suspend_ordering'
84  * kernel command line option that causes the following variable to be set.
85  */
86 static bool old_suspend_ordering;
87 
88 void __init acpi_old_suspend_ordering(void)
89 {
90 	old_suspend_ordering = true;
91 }
92 
93 /**
94  *	acpi_pm_disable_gpes - Disable the GPEs.
95  */
96 static int acpi_pm_disable_gpes(void)
97 {
98 	acpi_disable_all_gpes();
99 	return 0;
100 }
101 
102 /**
103  *	__acpi_pm_prepare - Prepare the platform to enter the target state.
104  *
105  *	If necessary, set the firmware waking vector and do arch-specific
106  *	nastiness to get the wakeup code to the waking vector.
107  */
108 static int __acpi_pm_prepare(void)
109 {
110 	int error = acpi_sleep_prepare(acpi_target_sleep_state);
111 
112 	if (error)
113 		acpi_target_sleep_state = ACPI_STATE_S0;
114 	return error;
115 }
116 
117 /**
118  *	acpi_pm_prepare - Prepare the platform to enter the target sleep
119  *		state and disable the GPEs.
120  */
121 static int acpi_pm_prepare(void)
122 {
123 	int error = __acpi_pm_prepare();
124 
125 	if (!error)
126 		acpi_disable_all_gpes();
127 	return error;
128 }
129 
130 /**
131  *	acpi_pm_finish - Instruct the platform to leave a sleep state.
132  *
133  *	This is called after we wake back up (or if entering the sleep state
134  *	failed).
135  */
136 static void acpi_pm_finish(void)
137 {
138 	u32 acpi_state = acpi_target_sleep_state;
139 
140 	if (acpi_state == ACPI_STATE_S0)
141 		return;
142 
143 	printk(KERN_INFO PREFIX "Waking up from system sleep state S%d\n",
144 		acpi_state);
145 	acpi_disable_wakeup_device(acpi_state);
146 	acpi_leave_sleep_state(acpi_state);
147 
148 	/* reset firmware waking vector */
149 	acpi_set_firmware_waking_vector((acpi_physical_address) 0);
150 
151 	acpi_target_sleep_state = ACPI_STATE_S0;
152 }
153 
154 /**
155  *	acpi_pm_end - Finish up suspend sequence.
156  */
157 static void acpi_pm_end(void)
158 {
159 	/*
160 	 * This is necessary in case acpi_pm_finish() is not called during a
161 	 * failing transition to a sleep state.
162 	 */
163 	acpi_target_sleep_state = ACPI_STATE_S0;
164 	acpi_sleep_tts_switch(acpi_target_sleep_state);
165 }
166 #else /* !CONFIG_ACPI_SLEEP */
167 #define acpi_target_sleep_state	ACPI_STATE_S0
168 #endif /* CONFIG_ACPI_SLEEP */
169 
170 #ifdef CONFIG_SUSPEND
171 /*
172  * According to the ACPI specification the BIOS should make sure that ACPI is
173  * enabled and SCI_EN bit is set on wake-up from S1 - S3 sleep states.  Still,
174  * some BIOSes don't do that and therefore we use acpi_enable() to enable ACPI
175  * on such systems during resume.  Unfortunately that doesn't help in
176  * particularly pathological cases in which SCI_EN has to be set directly on
177  * resume, although the specification states very clearly that this flag is
178  * owned by the hardware.  The set_sci_en_on_resume variable will be set in such
179  * cases.
180  */
181 static bool set_sci_en_on_resume;
182 
183 extern void do_suspend_lowlevel(void);
184 
185 static u32 acpi_suspend_states[] = {
186 	[PM_SUSPEND_ON] = ACPI_STATE_S0,
187 	[PM_SUSPEND_STANDBY] = ACPI_STATE_S1,
188 	[PM_SUSPEND_MEM] = ACPI_STATE_S3,
189 	[PM_SUSPEND_MAX] = ACPI_STATE_S5
190 };
191 
192 /**
193  *	acpi_suspend_begin - Set the target system sleep state to the state
194  *		associated with given @pm_state, if supported.
195  */
196 static int acpi_suspend_begin(suspend_state_t pm_state)
197 {
198 	u32 acpi_state = acpi_suspend_states[pm_state];
199 	int error = 0;
200 
201 	if (sleep_states[acpi_state]) {
202 		acpi_target_sleep_state = acpi_state;
203 		acpi_sleep_tts_switch(acpi_target_sleep_state);
204 	} else {
205 		printk(KERN_ERR "ACPI does not support this state: %d\n",
206 			pm_state);
207 		error = -ENOSYS;
208 	}
209 	return error;
210 }
211 
212 /**
213  *	acpi_suspend_enter - Actually enter a sleep state.
214  *	@pm_state: ignored
215  *
216  *	Flush caches and go to sleep. For STR we have to call arch-specific
217  *	assembly, which in turn call acpi_enter_sleep_state().
218  *	It's unfortunate, but it works. Please fix if you're feeling frisky.
219  */
220 static int acpi_suspend_enter(suspend_state_t pm_state)
221 {
222 	acpi_status status = AE_OK;
223 	unsigned long flags = 0;
224 	u32 acpi_state = acpi_target_sleep_state;
225 
226 	ACPI_FLUSH_CPU_CACHE();
227 
228 	/* Do arch specific saving of state. */
229 	if (acpi_state == ACPI_STATE_S3) {
230 		int error = acpi_save_state_mem();
231 
232 		if (error)
233 			return error;
234 	}
235 
236 	local_irq_save(flags);
237 	acpi_enable_wakeup_device(acpi_state);
238 	switch (acpi_state) {
239 	case ACPI_STATE_S1:
240 		barrier();
241 		status = acpi_enter_sleep_state(acpi_state);
242 		break;
243 
244 	case ACPI_STATE_S3:
245 		do_suspend_lowlevel();
246 		break;
247 	}
248 
249 	/* If ACPI is not enabled by the BIOS, we need to enable it here. */
250 	if (set_sci_en_on_resume)
251 		acpi_set_register(ACPI_BITREG_SCI_ENABLE, 1);
252 	else
253 		acpi_enable();
254 
255 	/* Reprogram control registers and execute _BFS */
256 	acpi_leave_sleep_state_prep(acpi_state);
257 
258 	/* ACPI 3.0 specs (P62) says that it's the responsibility
259 	 * of the OSPM to clear the status bit [ implying that the
260 	 * POWER_BUTTON event should not reach userspace ]
261 	 */
262 	if (ACPI_SUCCESS(status) && (acpi_state == ACPI_STATE_S3))
263 		acpi_clear_event(ACPI_EVENT_POWER_BUTTON);
264 
265 	/*
266 	 * Disable and clear GPE status before interrupt is enabled. Some GPEs
267 	 * (like wakeup GPE) haven't handler, this can avoid such GPE misfire.
268 	 * acpi_leave_sleep_state will reenable specific GPEs later
269 	 */
270 	acpi_disable_all_gpes();
271 
272 	local_irq_restore(flags);
273 	printk(KERN_DEBUG "Back to C!\n");
274 
275 	/* restore processor state */
276 	if (acpi_state == ACPI_STATE_S3)
277 		acpi_restore_state_mem();
278 
279 	return ACPI_SUCCESS(status) ? 0 : -EFAULT;
280 }
281 
282 static int acpi_suspend_state_valid(suspend_state_t pm_state)
283 {
284 	u32 acpi_state;
285 
286 	switch (pm_state) {
287 	case PM_SUSPEND_ON:
288 	case PM_SUSPEND_STANDBY:
289 	case PM_SUSPEND_MEM:
290 		acpi_state = acpi_suspend_states[pm_state];
291 
292 		return sleep_states[acpi_state];
293 	default:
294 		return 0;
295 	}
296 }
297 
298 static struct platform_suspend_ops acpi_suspend_ops = {
299 	.valid = acpi_suspend_state_valid,
300 	.begin = acpi_suspend_begin,
301 	.prepare = acpi_pm_prepare,
302 	.enter = acpi_suspend_enter,
303 	.finish = acpi_pm_finish,
304 	.end = acpi_pm_end,
305 };
306 
307 /**
308  *	acpi_suspend_begin_old - Set the target system sleep state to the
309  *		state associated with given @pm_state, if supported, and
310  *		execute the _PTS control method.  This function is used if the
311  *		pre-ACPI 2.0 suspend ordering has been requested.
312  */
313 static int acpi_suspend_begin_old(suspend_state_t pm_state)
314 {
315 	int error = acpi_suspend_begin(pm_state);
316 
317 	if (!error)
318 		error = __acpi_pm_prepare();
319 	return error;
320 }
321 
322 /*
323  * The following callbacks are used if the pre-ACPI 2.0 suspend ordering has
324  * been requested.
325  */
326 static struct platform_suspend_ops acpi_suspend_ops_old = {
327 	.valid = acpi_suspend_state_valid,
328 	.begin = acpi_suspend_begin_old,
329 	.prepare = acpi_pm_disable_gpes,
330 	.enter = acpi_suspend_enter,
331 	.finish = acpi_pm_finish,
332 	.end = acpi_pm_end,
333 	.recover = acpi_pm_finish,
334 };
335 
336 static int __init init_old_suspend_ordering(const struct dmi_system_id *d)
337 {
338 	old_suspend_ordering = true;
339 	return 0;
340 }
341 
342 static int __init init_set_sci_en_on_resume(const struct dmi_system_id *d)
343 {
344 	set_sci_en_on_resume = true;
345 	return 0;
346 }
347 
348 static struct dmi_system_id __initdata acpisleep_dmi_table[] = {
349 	{
350 	.callback = init_old_suspend_ordering,
351 	.ident = "Abit KN9 (nForce4 variant)",
352 	.matches = {
353 		DMI_MATCH(DMI_BOARD_VENDOR, "http://www.abit.com.tw/"),
354 		DMI_MATCH(DMI_BOARD_NAME, "KN9 Series(NF-CK804)"),
355 		},
356 	},
357 	{
358 	.callback = init_old_suspend_ordering,
359 	.ident = "HP xw4600 Workstation",
360 	.matches = {
361 		DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
362 		DMI_MATCH(DMI_PRODUCT_NAME, "HP xw4600 Workstation"),
363 		},
364 	},
365 	{
366 	.callback = init_set_sci_en_on_resume,
367 	.ident = "Apple MacBook 1,1",
368 	.matches = {
369 		DMI_MATCH(DMI_SYS_VENDOR, "Apple Computer, Inc."),
370 		DMI_MATCH(DMI_PRODUCT_NAME, "MacBook1,1"),
371 		},
372 	},
373 	{
374 	.callback = init_set_sci_en_on_resume,
375 	.ident = "Apple MacMini 1,1",
376 	.matches = {
377 		DMI_MATCH(DMI_SYS_VENDOR, "Apple Computer, Inc."),
378 		DMI_MATCH(DMI_PRODUCT_NAME, "Macmini1,1"),
379 		},
380 	},
381 	{},
382 };
383 #endif /* CONFIG_SUSPEND */
384 
385 #ifdef CONFIG_HIBERNATION
386 /*
387  * The ACPI specification wants us to save NVS memory regions during hibernation
388  * and to restore them during the subsequent resume.  However, it is not certain
389  * if this mechanism is going to work on all machines, so we allow the user to
390  * disable this mechanism using the 'acpi_sleep=s4_nonvs' kernel command line
391  * option.
392  */
393 static bool s4_no_nvs;
394 
395 void __init acpi_s4_no_nvs(void)
396 {
397 	s4_no_nvs = true;
398 }
399 
400 static unsigned long s4_hardware_signature;
401 static struct acpi_table_facs *facs;
402 static bool nosigcheck;
403 
404 void __init acpi_no_s4_hw_signature(void)
405 {
406 	nosigcheck = true;
407 }
408 
409 static int acpi_hibernation_begin(void)
410 {
411 	int error;
412 
413 	error = s4_no_nvs ? 0 : hibernate_nvs_alloc();
414 	if (!error) {
415 		acpi_target_sleep_state = ACPI_STATE_S4;
416 		acpi_sleep_tts_switch(acpi_target_sleep_state);
417 	}
418 
419 	return error;
420 }
421 
422 static int acpi_hibernation_pre_snapshot(void)
423 {
424 	int error = acpi_pm_prepare();
425 
426 	if (!error)
427 		hibernate_nvs_save();
428 
429 	return error;
430 }
431 
432 static int acpi_hibernation_enter(void)
433 {
434 	acpi_status status = AE_OK;
435 	unsigned long flags = 0;
436 
437 	ACPI_FLUSH_CPU_CACHE();
438 
439 	local_irq_save(flags);
440 	acpi_enable_wakeup_device(ACPI_STATE_S4);
441 	/* This shouldn't return.  If it returns, we have a problem */
442 	status = acpi_enter_sleep_state(ACPI_STATE_S4);
443 	/* Reprogram control registers and execute _BFS */
444 	acpi_leave_sleep_state_prep(ACPI_STATE_S4);
445 	local_irq_restore(flags);
446 
447 	return ACPI_SUCCESS(status) ? 0 : -EFAULT;
448 }
449 
450 static void acpi_hibernation_finish(void)
451 {
452 	hibernate_nvs_free();
453 	acpi_pm_finish();
454 }
455 
456 static void acpi_hibernation_leave(void)
457 {
458 	/*
459 	 * If ACPI is not enabled by the BIOS and the boot kernel, we need to
460 	 * enable it here.
461 	 */
462 	acpi_enable();
463 	/* Reprogram control registers and execute _BFS */
464 	acpi_leave_sleep_state_prep(ACPI_STATE_S4);
465 	/* Check the hardware signature */
466 	if (facs && s4_hardware_signature != facs->hardware_signature) {
467 		printk(KERN_EMERG "ACPI: Hardware changed while hibernated, "
468 			"cannot resume!\n");
469 		panic("ACPI S4 hardware signature mismatch");
470 	}
471 	/* Restore the NVS memory area */
472 	hibernate_nvs_restore();
473 }
474 
475 static void acpi_pm_enable_gpes(void)
476 {
477 	acpi_enable_all_runtime_gpes();
478 }
479 
480 static struct platform_hibernation_ops acpi_hibernation_ops = {
481 	.begin = acpi_hibernation_begin,
482 	.end = acpi_pm_end,
483 	.pre_snapshot = acpi_hibernation_pre_snapshot,
484 	.finish = acpi_hibernation_finish,
485 	.prepare = acpi_pm_prepare,
486 	.enter = acpi_hibernation_enter,
487 	.leave = acpi_hibernation_leave,
488 	.pre_restore = acpi_pm_disable_gpes,
489 	.restore_cleanup = acpi_pm_enable_gpes,
490 };
491 
492 /**
493  *	acpi_hibernation_begin_old - Set the target system sleep state to
494  *		ACPI_STATE_S4 and execute the _PTS control method.  This
495  *		function is used if the pre-ACPI 2.0 suspend ordering has been
496  *		requested.
497  */
498 static int acpi_hibernation_begin_old(void)
499 {
500 	int error;
501 	/*
502 	 * The _TTS object should always be evaluated before the _PTS object.
503 	 * When the old_suspended_ordering is true, the _PTS object is
504 	 * evaluated in the acpi_sleep_prepare.
505 	 */
506 	acpi_sleep_tts_switch(ACPI_STATE_S4);
507 
508 	error = acpi_sleep_prepare(ACPI_STATE_S4);
509 
510 	if (!error) {
511 		if (!s4_no_nvs)
512 			error = hibernate_nvs_alloc();
513 		if (!error)
514 			acpi_target_sleep_state = ACPI_STATE_S4;
515 	}
516 	return error;
517 }
518 
519 static int acpi_hibernation_pre_snapshot_old(void)
520 {
521 	int error = acpi_pm_disable_gpes();
522 
523 	if (!error)
524 		hibernate_nvs_save();
525 
526 	return error;
527 }
528 
529 /*
530  * The following callbacks are used if the pre-ACPI 2.0 suspend ordering has
531  * been requested.
532  */
533 static struct platform_hibernation_ops acpi_hibernation_ops_old = {
534 	.begin = acpi_hibernation_begin_old,
535 	.end = acpi_pm_end,
536 	.pre_snapshot = acpi_hibernation_pre_snapshot_old,
537 	.finish = acpi_hibernation_finish,
538 	.prepare = acpi_pm_disable_gpes,
539 	.enter = acpi_hibernation_enter,
540 	.leave = acpi_hibernation_leave,
541 	.pre_restore = acpi_pm_disable_gpes,
542 	.restore_cleanup = acpi_pm_enable_gpes,
543 	.recover = acpi_pm_finish,
544 };
545 #endif /* CONFIG_HIBERNATION */
546 
547 int acpi_suspend(u32 acpi_state)
548 {
549 	suspend_state_t states[] = {
550 		[1] = PM_SUSPEND_STANDBY,
551 		[3] = PM_SUSPEND_MEM,
552 		[5] = PM_SUSPEND_MAX
553 	};
554 
555 	if (acpi_state < 6 && states[acpi_state])
556 		return pm_suspend(states[acpi_state]);
557 	if (acpi_state == 4)
558 		return hibernate();
559 	return -EINVAL;
560 }
561 
562 #ifdef CONFIG_PM_SLEEP
563 /**
564  *	acpi_pm_device_sleep_state - return preferred power state of ACPI device
565  *		in the system sleep state given by %acpi_target_sleep_state
566  *	@dev: device to examine; its driver model wakeup flags control
567  *		whether it should be able to wake up the system
568  *	@d_min_p: used to store the upper limit of allowed states range
569  *	Return value: preferred power state of the device on success, -ENODEV on
570  *		failure (ie. if there's no 'struct acpi_device' for @dev)
571  *
572  *	Find the lowest power (highest number) ACPI device power state that
573  *	device @dev can be in while the system is in the sleep state represented
574  *	by %acpi_target_sleep_state.  If @wake is nonzero, the device should be
575  *	able to wake up the system from this sleep state.  If @d_min_p is set,
576  *	the highest power (lowest number) device power state of @dev allowed
577  *	in this system sleep state is stored at the location pointed to by it.
578  *
579  *	The caller must ensure that @dev is valid before using this function.
580  *	The caller is also responsible for figuring out if the device is
581  *	supposed to be able to wake up the system and passing this information
582  *	via @wake.
583  */
584 
585 int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p)
586 {
587 	acpi_handle handle = DEVICE_ACPI_HANDLE(dev);
588 	struct acpi_device *adev;
589 	char acpi_method[] = "_SxD";
590 	unsigned long long d_min, d_max;
591 
592 	if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &adev))) {
593 		printk(KERN_DEBUG "ACPI handle has no context!\n");
594 		return -ENODEV;
595 	}
596 
597 	acpi_method[2] = '0' + acpi_target_sleep_state;
598 	/*
599 	 * If the sleep state is S0, we will return D3, but if the device has
600 	 * _S0W, we will use the value from _S0W
601 	 */
602 	d_min = ACPI_STATE_D0;
603 	d_max = ACPI_STATE_D3;
604 
605 	/*
606 	 * If present, _SxD methods return the minimum D-state (highest power
607 	 * state) we can use for the corresponding S-states.  Otherwise, the
608 	 * minimum D-state is D0 (ACPI 3.x).
609 	 *
610 	 * NOTE: We rely on acpi_evaluate_integer() not clobbering the integer
611 	 * provided -- that's our fault recovery, we ignore retval.
612 	 */
613 	if (acpi_target_sleep_state > ACPI_STATE_S0)
614 		acpi_evaluate_integer(handle, acpi_method, NULL, &d_min);
615 
616 	/*
617 	 * If _PRW says we can wake up the system from the target sleep state,
618 	 * the D-state returned by _SxD is sufficient for that (we assume a
619 	 * wakeup-aware driver if wake is set).  Still, if _SxW exists
620 	 * (ACPI 3.x), it should return the maximum (lowest power) D-state that
621 	 * can wake the system.  _S0W may be valid, too.
622 	 */
623 	if (acpi_target_sleep_state == ACPI_STATE_S0 ||
624 	    (device_may_wakeup(dev) && adev->wakeup.state.enabled &&
625 	     adev->wakeup.sleep_state <= acpi_target_sleep_state)) {
626 		acpi_status status;
627 
628 		acpi_method[3] = 'W';
629 		status = acpi_evaluate_integer(handle, acpi_method, NULL,
630 						&d_max);
631 		if (ACPI_FAILURE(status)) {
632 			d_max = d_min;
633 		} else if (d_max < d_min) {
634 			/* Warn the user of the broken DSDT */
635 			printk(KERN_WARNING "ACPI: Wrong value from %s\n",
636 				acpi_method);
637 			/* Sanitize it */
638 			d_min = d_max;
639 		}
640 	}
641 
642 	if (d_min_p)
643 		*d_min_p = d_min;
644 	return d_max;
645 }
646 
647 /**
648  *	acpi_pm_device_sleep_wake - enable or disable the system wake-up
649  *                                  capability of given device
650  *	@dev: device to handle
651  *	@enable: 'true' - enable, 'false' - disable the wake-up capability
652  */
653 int acpi_pm_device_sleep_wake(struct device *dev, bool enable)
654 {
655 	acpi_handle handle;
656 	struct acpi_device *adev;
657 
658 	if (!device_may_wakeup(dev))
659 		return -EINVAL;
660 
661 	handle = DEVICE_ACPI_HANDLE(dev);
662 	if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &adev))) {
663 		printk(KERN_DEBUG "ACPI handle has no context!\n");
664 		return -ENODEV;
665 	}
666 
667 	return enable ?
668 		acpi_enable_wakeup_device_power(adev, acpi_target_sleep_state) :
669 		acpi_disable_wakeup_device_power(adev);
670 }
671 #endif
672 
673 static void acpi_power_off_prepare(void)
674 {
675 	/* Prepare to power off the system */
676 	acpi_sleep_prepare(ACPI_STATE_S5);
677 	acpi_disable_all_gpes();
678 }
679 
680 static void acpi_power_off(void)
681 {
682 	/* acpi_sleep_prepare(ACPI_STATE_S5) should have already been called */
683 	printk(KERN_DEBUG "%s called\n", __func__);
684 	local_irq_disable();
685 	acpi_enable_wakeup_device(ACPI_STATE_S5);
686 	acpi_enter_sleep_state(ACPI_STATE_S5);
687 }
688 
689 int __init acpi_sleep_init(void)
690 {
691 	acpi_status status;
692 	u8 type_a, type_b;
693 #ifdef CONFIG_SUSPEND
694 	int i = 0;
695 
696 	dmi_check_system(acpisleep_dmi_table);
697 #endif
698 
699 	if (acpi_disabled)
700 		return 0;
701 
702 	sleep_states[ACPI_STATE_S0] = 1;
703 	printk(KERN_INFO PREFIX "(supports S0");
704 
705 #ifdef CONFIG_SUSPEND
706 	for (i = ACPI_STATE_S1; i < ACPI_STATE_S4; i++) {
707 		status = acpi_get_sleep_type_data(i, &type_a, &type_b);
708 		if (ACPI_SUCCESS(status)) {
709 			sleep_states[i] = 1;
710 			printk(" S%d", i);
711 		}
712 	}
713 
714 	suspend_set_ops(old_suspend_ordering ?
715 		&acpi_suspend_ops_old : &acpi_suspend_ops);
716 #endif
717 
718 #ifdef CONFIG_HIBERNATION
719 	status = acpi_get_sleep_type_data(ACPI_STATE_S4, &type_a, &type_b);
720 	if (ACPI_SUCCESS(status)) {
721 		hibernation_set_ops(old_suspend_ordering ?
722 			&acpi_hibernation_ops_old : &acpi_hibernation_ops);
723 		sleep_states[ACPI_STATE_S4] = 1;
724 		printk(" S4");
725 		if (!nosigcheck) {
726 			acpi_get_table(ACPI_SIG_FACS, 1,
727 				(struct acpi_table_header **)&facs);
728 			if (facs)
729 				s4_hardware_signature =
730 					facs->hardware_signature;
731 		}
732 	}
733 #endif
734 	status = acpi_get_sleep_type_data(ACPI_STATE_S5, &type_a, &type_b);
735 	if (ACPI_SUCCESS(status)) {
736 		sleep_states[ACPI_STATE_S5] = 1;
737 		printk(" S5");
738 		pm_power_off_prepare = acpi_power_off_prepare;
739 		pm_power_off = acpi_power_off;
740 	}
741 	printk(")\n");
742 	/*
743 	 * Register the tts_notifier to reboot notifier list so that the _TTS
744 	 * object can also be evaluated when the system enters S5.
745 	 */
746 	register_reboot_notifier(&tts_notifier);
747 	return 0;
748 }
749