summaryrefslogtreecommitdiffstats
path: root/include/linux/pm.h
blob: 52e8c55ff314ce9ffa92b14b11ff5603a4e77eb6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
/*
 *  pm.h - Power management interface
 *
 *  Copyright (C) 2000 Andrew Henroid
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#ifndef _LINUX_PM_H
#define _LINUX_PM_H

#include <linux/list.h>
#include <linux/workqueue.h>
#include <linux/spinlock.h>
#include <linux/wait.h>
#include <linux/timer.h>
#include <linux/completion.h>

/*
 * Callbacks for platform drivers to implement.
 */
extern void (*pm_idle)(void);
extern void (*pm_power_off)(void);
extern void (*pm_power_off_prepare)(void);

/*
 * Device power management
 */

struct device;

typedef struct pm_message {
	int event;
} pm_message_t;

/**
 * struct dev_pm_ops - device PM callbacks
 *
 * Several driver power state transitions are externally visible, affecting
 * the state of pending I/O queues and (for drivers that touch hardware)
 * interrupts, wakeups, DMA, and other hardware state.  There may also be
 * internal transitions to various low power modes, which are transparent
 * to the rest of the driver stack (such as a driver that's ON gating off
 * clocks which are not in active use).
 *
 * The externally visible transitions are handled with the help of the following
 * callbacks included in this structure:
 *
 * @prepare: Prepare the device for the upcoming transition, but do NOT change
 *	its hardware state.  Prevent new children of the device from being
 *	registered after @prepare() returns (the driver's subsystem and
 *	generally the rest of the kernel is supposed to prevent new calls to the
 *	probe method from being made too once @prepare() has succeeded).  If
 *	@prepare() detects a situation it cannot handle (e.g. registration of a
 *	child already in progress), it may return -EAGAIN, so that the PM core
 *	can execute it once again (e.g. after the new child has been registered)
 *	to recover from the race condition.  This method is executed for all
 *	kinds of suspend transitions and is followed by one of the suspend
 *	callbacks: @suspend(), @freeze(), or @poweroff().
 *	The PM core executes @prepare() for all devices before starting to
 *	execute suspend callbacks for any of them, so drivers may assume all of
 *	the other devices to be present and functional while @prepare() is being
 *	executed.  In particular, it is safe to make GFP_KERNEL memory
 *	allocations from within @prepare().  However, drivers may NOT assume
 *	anything about the availability of the user space at that time and it
 *	is not correct to request firmware from within @prepare() (it's too
 *	late to do that).  [To work around this limitation, drivers may
 *	register suspend and hibernation notifiers that are executed before the
 *	freezing of tasks.]
 *
 * @complete: Undo the changes made by @prepare().  This method is executed for
 *	all kinds of resume transitions, following one of the resume callbacks:
 *	@resume(), @thaw(), @restore().  Also called if the state transition
 *	fails before the driver's suspend callback (@suspend(), @freeze(),
 *	@poweroff()) can be executed (e.g. if the suspend callback fails for one
 *	of the other devices that the PM core has unsuccessfully attempted to
 *	suspend earlier).
 *	The PM core executes @complete() after it has executed the appropriate
 *	resume callback for all devices.
 *
 * @suspend: Executed before putting the system into a sleep state in which the
 *	contents of main memory are preserved.  Quiesce the device, put it into
 *	a low power state appropriate for the upcoming system state (such as
 *	PCI_D3hot), and enable wakeup events as appropriate.
 *
 * @resume: Executed after waking the system up from a sleep state in which the
 *	contents of main memory were preserved.  Put the device into the
 *	appropriate state, according to the information saved in memory by the
 *	preceding @suspend().  The driver starts working again, responding to
 *	hardware events and software requests.  The hardware may have gone
 *	through a power-off reset, or it may have maintained state from the
 *	previous suspend() which the driver may rely on while resuming.  On most
 *	platforms, there are no restrictions on availability of resources like
 *	clocks during @resume().
 *
 * @freeze: Hibernation-specific, executed before creating a hibernation image.
 *	Quiesce operations so that a consistent image can be created, but do NOT
 *	otherwise put the device into a low power device state and do NOT emit
 *	system wakeup events.  Save in main memory the device settings to be
 *	used by @restore() during the subsequent resume from hibernation or by
 *	the subsequent @thaw(), if the creation of the image or the restoration
 *	of main memory contents from it fails.
 *
 * @thaw: Hibernation-specific, executed after creating a hibernation image OR
 *	if the creation of the image fails.  Also executed after a failing
 *	attempt to restore the contents of main memory from such an image.
 *	Undo the changes made by the preceding @freeze(), so the device can be
 *	operated in the same way as immediately before the call to @freeze().
 *
 * @poweroff: Hibernation-specific, executed after saving a hibernation image.
 *	Quiesce the device, put it into a low power state appropriate for the
 *	upcoming system state (such as PCI_D3hot), and enable wakeup events as
 *	appropriate.
 *
 * @restore: Hibernation-specific, executed after restoring the contents of main
 *	memory from a hibernation image.  Driver starts working again,
 *	responding to hardware events and software requests.  Drivers may NOT
 *	make ANY assumptions about the hardware state right prior to @restore().
 *	On most platforms, there are no restrictions on availability of
 *	resources like clocks during @restore().
 *
 * @suspend_noirq: Complete the operations of ->suspend() by carrying out any
 *	actions required for suspending the device that need interrupts to be
 *	disabled
 *
 * @resume_noirq: Prepare for the execution of ->resume() by carrying out any
 *	actions required for resuming the device that need interrupts to be
 *	disabled
 *
 * @freeze_noirq: Complete the operations of ->freeze() by carrying out any
 *	actions required for freezing the device that need interrupts to be
 *	disabled
 *
 * @thaw_noirq: Prepare for the execution of ->thaw() by carrying out any
 *	actions required for thawing the device that need interrupts to be
 *	disabled
 *
 * @poweroff_noirq: Complete the operations of ->poweroff() by carrying out any
 *	actions required for handling the device that need interrupts to be
 *	disabled
 *
 * @restore_noirq: Prepare for the execution of ->restore() by carrying out any
 *	actions required for restoring the operations of the device that need
 *	interrupts to be disabled
 *
 * All of the above callbacks, except for @complete(), return error codes.
 * However, the error codes returned by the resume operations, @resume(),
 * @thaw(), @restore(), @resume_noirq(), @thaw_noirq(), and @restore_noirq() do
 * not cause the PM core to abort the resume transition during which they are
 * returned.  The error codes returned in that cases are only printed by the PM
 * core to the system logs for debugging purposes.  Still, it is recommended
 * that drivers only return error codes from their resume methods in case of an
 * unrecoverable failure (i.e. when the device being handled refuses to resume
 * and becomes unusable) to allow us to modify the PM core in the future, so
 * that it can avoid attempting to handle devices that failed to resume and
 * their children.
 *
 * It is allowed to unregister devices while the above callbacks are being
 * executed.  However, it is not allowed to unregister a device from within any
 * of its own callbacks.
 *
 * There also are the following callbacks related to run-time power management
 * of devices:
 *
 * @runtime_suspend: Prepare the device for a condition in which it won't be
 *	able to communicate with the CPU(s) and RAM due to power management.
 *	This need not mean that the device should be put into a low power state.
 *	For example, if the device is behind a link which is about to be turned
 *	off, the device may remain at full power.  If the device does go to low
 *	power and is capable of generating run-time wake-up events, remote
 *	wake-up (i.e., a hardware mechanism allowing the device to request a
 *	change of its power state via a wake-up event, such as PCI PME) should
 *	be enabled for it.
 *
 * @runtime_resume: Put the device into the fully active state in response to a
 *	wake-up event generated by hardware or at the request of software.  If
 *	necessary, put the device into the full power state and restore its
 *	registers, so that it is fully operational.
 *
 * @runtime_idle: Device appears to be inactive and it might be put into a low
 *	power state if all of the necessary conditions are satisfied.  Check
 *	these conditions and handle the device as appropriate, possibly queueing
 *	a suspend request for it.  The return value is ignored by the PM core.
 */

struct dev_pm_ops {
	int (*prepare)(struct device *dev);
	void (*complete)(struct device *dev);
	int (*suspend)(struct device *dev);
	int (*resume)(struct device *dev);
	int (*freeze)(struct device *dev);
	int (*thaw)(struct device *dev);
	int (*poweroff)(struct device *dev);
	int (*restore)(struct device *dev);
	int (*suspend_noirq)(struct device *dev);
	int (*resume_noirq)(struct device *dev);
	int (*freeze_noirq)(struct device *dev);
	int (*thaw_noirq)(struct device *dev);
	int (*poweroff_noirq)(struct device *dev);
	int (*restore_noirq)(struct device *dev);
	int (*runtime_suspend)(struct device *dev);
	int (*runtime_resume)(struct device *dev);
	int (*runtime_idle)(struct device *dev);
};

#ifdef CONFIG_PM_SLEEP
#define SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
	.suspend = suspend_fn, \
	.resume = resume_fn, \
	.freeze = suspend_fn, \
	.thaw = resume_fn, \
	.poweroff = suspend_fn, \
	.restore = resume_fn,
#else
#define SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn)
#endif

#ifdef CONFIG_PM_RUNTIME
#define SET_RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn) \
	.runtime_suspend = suspend_fn, \
	.runtime_resume = resume_fn, \
	.runtime_idle = idle_fn,
#else
#define SET_RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn)
#endif

/*
 * Use this if you want to use the same suspend and resume callbacks for suspend
 * to RAM and hibernation.
 */
#define SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn) \
const struct dev_pm_ops name = { \
	SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
}

/*
 * Use this for defining a set of PM operations to be used in all situations
 * (sustem suspend, hibernation or runtime PM).
 */
#define UNIVERSAL_DEV_PM_OPS(name, suspend_fn, resume_fn, idle_fn) \
const struct dev_pm_ops name = { \
	SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
	SET_RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn) \
}

/*
 * Use this for subsystems (bus types, device types, device classes) that don't
 * need any special suspend/resume handling in addition to invoking the PM
 * callbacks provided by device drivers supporting both the system sleep PM and
 * runtime PM, make the pm member point to generic_subsys_pm_ops.
 */
#ifdef CONFIG_PM_OPS
extern struct dev_pm_ops generic_subsys_pm_ops;
#define GENERIC_SUBSYS_PM_OPS	(&generic_subsys_pm_ops)
#else
#define GENERIC_SUBSYS_PM_OPS	NULL
#endif

/**
 * PM_EVENT_ messages
 *
 * The following PM_EVENT_ messages are defined for the internal use of the PM
 * core, in order to provide a mechanism allowing the high level suspend and
 * hibernation code to convey the necessary information to the device PM core
 * code:
 *
 * ON		No transition.
 *
 * FREEZE 	System is going to hibernate, call ->prepare() and ->freeze()
 *		for all devices.
 *
 * SUSPEND	System is going to suspend, call ->prepare() and ->suspend()
 *		for all devices.
 *
 * HIBERNATE	Hibernation image has been saved, call ->prepare() and
 *		->poweroff() for all devices.
 *
 * QUIESCE	Contents of main memory are going to be restored from a (loaded)
 *		hibernation image, call ->prepare() and ->freeze() for all
 *		devices.
 *
 * RESUME	System is resuming, call ->resume() and ->complete() for all
 *		devices.
 *
 * THAW		Hibernation image has been created, call ->thaw() and
 *		->complete() for all devices.
 *
 * RESTORE	Contents of main memory have been restored from a hibernation
 *		image, call ->restore() and ->complete() for all devices.
 *
 * RECOVER	Creation of a hibernation image or restoration of the main
 *		memory contents from a hibernation image has failed, call
 *		->thaw() and ->complete() for all devices.
 *
 * The following PM_EVENT_ messages are defined for internal use by
 * kernel subsystems.  They are never issued by the PM core.
 *
 * USER_SUSPEND		Manual selective suspend was issued by userspace.
 *
 * USER_RESUME		Manual selective resume was issued by userspace.
 *
 * REMOTE_WAKEUP	Remote-wakeup request was received from the device.
 *
 * AUTO_SUSPEND		Automatic (device idle) runtime suspend was
 *			initiated by the subsystem.
 *
 * AUTO_RESUME		Automatic (device needed) runtime resume was
 *			requested by a driver.
 */

#define PM_EVENT_ON		0x0000
#define PM_EVENT_FREEZE 	0x0001
#define PM_EVENT_SUSPEND	0x0002
#define PM_EVENT_HIBERNATE	0x0004
#define PM_EVENT_QUIESCE	0x0008
#define PM_EVENT_RESUME		0x0010
#define PM_EVENT_THAW		0x0020
#define PM_EVENT_RESTORE	0x0040
#define PM_EVENT_RECOVER	0x0080
#define PM_EVENT_USER		0x0100
#define PM_EVENT_REMOTE		0x0200
#define PM_EVENT_AUTO		0x0400

#define PM_EVENT_SLEEP		(PM_EVENT_SUSPEND | PM_EVENT_HIBERNATE)
#define PM_EVENT_USER_SUSPEND	(PM_EVENT_USER | PM_EVENT_SUSPEND)
#define PM_EVENT_USER_RESUME	(PM_EVENT_USER | PM_EVENT_RESUME)
#define PM_EVENT_REMOTE_RESUME	(PM_EVENT_REMOTE | PM_EVENT_RESUME)
#define PM_EVENT_AUTO_SUSPEND	(PM_EVENT_AUTO | PM_EVENT_SUSPEND)
#define PM_EVENT_AUTO_RESUME	(PM_EVENT_AUTO | PM_EVENT_RESUME)

#define PMSG_ON		((struct pm_message){ .event = PM_EVENT_ON, })
#define PMSG_FREEZE	((struct pm_message){ .event = PM_EVENT_FREEZE, })
#define PMSG_QUIESCE	((struct pm_message){ .event = PM_EVENT_QUIESCE, })
#define PMSG_SUSPEND	((struct pm_message){ .event = PM_EVENT_SUSPEND, })
#define PMSG_HIBERNATE	((struct pm_message){ .event = PM_EVENT_HIBERNATE, })
#define PMSG_RESUME	((struct pm_message){ .event = PM_EVENT_RESUME, })
#define PMSG_THAW	((struct pm_message){ .event = PM_EVENT_THAW, })
#define PMSG_RESTORE	((struct pm_message){ .event = PM_EVENT_RESTORE, })
#define PMSG_RECOVER	((struct pm_message){ .event = PM_EVENT_RECOVER, })
#define PMSG_USER_SUSPEND	((struct pm_message) \
					{ .event = PM_EVENT_USER_SUSPEND, })
#define PMSG_USER_RESUME	((struct pm_message) \
					{ .event = PM_EVENT_USER_RESUME, })
#define PMSG_REMOTE_RESUME	((struct pm_message) \
					{ .event = PM_EVENT_REMOTE_RESUME, })
#define PMSG_AUTO_SUSPEND	((struct pm_message) \
					{ .event = PM_EVENT_AUTO_SUSPEND, })
#define PMSG_AUTO_RESUME	((struct pm_message) \
					{ .event = PM_EVENT_AUTO_RESUME, })

/**
 * Device power management states
 *
 * These state labels are used internally by the PM core to indicate the current
 * status of a device with respect to the PM core operations.
 *
 * DPM_ON		Device is regarded as operational.  Set this way
 *			initially and when ->complete() is about to be called.
 *			Also set when ->prepare() fails.
 *
 * DPM_PREPARING	Device is going to be prepared for a PM transition.  Set
 *			when ->prepare() is about to be called.
 *
 * DPM_RESUMING		Device is going to be resumed.  Set when ->resume(),
 *			->thaw(), or ->restore() is about to be called.
 *
 * DPM_SUSPENDING	Device has been prepared for a power transition.  Set
 *			when ->prepare() has just succeeded.
 *
 * DPM_OFF		Device is regarded as inactive.  Set immediately after
 *			->suspend(), ->freeze(), or ->poweroff() has succeeded.
 *			Also set when ->resume()_noirq, ->thaw_noirq(), or
 *			->restore_noirq() is about to be called.
 *
 * DPM_OFF_IRQ		Device is in a "deep sleep".  Set immediately after
 *			->suspend_noirq(), ->freeze_noirq(), or
 *			->poweroff_noirq() has just succeeded.
 */

enum dpm_state {
	DPM_INVALID,
	DPM_ON,
	DPM_PREPARING,
	DPM_RESUMING,
	DPM_SUSPENDING,
	DPM_OFF,
	DPM_OFF_IRQ,
};

/**
 * Device run-time power management status.
 *
 * These status labels are used internally by the PM core to indicate the
 * current status of a device with respect to the PM core operations.  They do
 * not reflect the actual power state of the device or its status as seen by the
 * driver.
 *
 * RPM_ACTIVE		Device is fully operational.  Indicates that the device
 *			bus type's ->runtime_resume() callback has completed
 *			successfully.
 *
 * RPM_SUSPENDED	Device bus type's ->runtime_suspend() callback has
 *			completed successfully.  The device is regarded as
 *			suspended.
 *
 * RPM_RESUMING		Device bus type's ->runtime_resume() callback is being
 *			executed.
 *
 * RPM_SUSPENDING	Device bus type's ->runtime_suspend() callback is being
 *			executed.
 */

enum rpm_status {
	RPM_ACTIVE = 0,
	RPM_RESUMING,
	RPM_SUSPENDED,
	RPM_SUSPENDING,
};

/**
 * Device run-time power management request types.
 *
 * RPM_REQ_NONE		Do nothing.
 *
 * RPM_REQ_IDLE		Run the device bus type's ->runtime_idle() callback
 *
 * RPM_REQ_SUSPEND	Run the device bus type's ->runtime_suspend() callback
 *
 * RPM_REQ_RESUME	Run the device bus type's ->runtime_resume() callback
 */

enum rpm_request {
	RPM_REQ_NONE = 0,
	RPM_REQ_IDLE,
	RPM_REQ_SUSPEND,
	RPM_REQ_RESUME,
};

struct dev_pm_info {
	pm_message_t		power_state;
	unsigned int		can_wakeup:1;
	unsigned int		should_wakeup:1;
	unsigned		async_suspend:1;
	enum dpm_state		status;		/* Owned by the PM core */
#ifdef CONFIG_PM_SLEEP
	struct list_head	entry;
	struct completion	completion;
	unsigned long		wakeup_count;
#endif
#ifdef CONFIG_PM_RUNTIME
	struct timer_list	suspend_timer;
	unsigned long		timer_expires;
	struct work_struct	work;
	wait_queue_head_t	wait_queue;
	spinlock_t		lock;
	atomic_t		usage_count;
	atomic_t		child_count;
	unsigned int		disable_depth:3;
	unsigned int		ignore_children:1;
	unsigned int		idle_notification:1;
	unsigned int		request_pending:1;
	unsigned int		deferred_resume:1;
	unsigned int		run_wake:1;
	unsigned int		runtime_auto:1;
	enum rpm_request	request;
	enum rpm_status		runtime_status;
	int			runtime_error;
	unsigned long		active_jiffies;
	unsigned long		suspended_jiffies;
	unsigned long		accounting_timestamp;
#endif
};

extern void update_pm_runtime_accounting(struct device *dev);


/*
 * The PM_EVENT_ messages are also used by drivers implementing the legacy
 * suspend framework, based on the ->suspend() and ->resume() callbacks common
 * for suspend and hibernation transitions, according to the rules below.
 */

/* Necessary, because several drivers use PM_EVENT_PRETHAW */
#define PM_EVENT_PRETHAW PM_EVENT_QUIESCE

/*
 * One transition is triggered by resume(), after a suspend() call; the
 * message is implicit:
 *
 * ON		Driver starts working again, responding to hardware events
 * 		and software requests.  The hardware may have gone through
 * 		a power-off reset, or it may have maintained state from the
 * 		previous suspend() which the driver will rely on while
 * 		resuming.  On most platforms, there are no restrictions on
 * 		availability of resources like clocks during resume().
 *
 * Other transitions are triggered by messages sent using suspend().  All
 * these transitions quiesce the driver, so that I/O queues are inactive.
 * That commonly entails turning off IRQs and DMA; there may be rules
 * about how to quiesce that are specific to the bus or the device's type.
 * (For example, network drivers mark the link state.)  Other details may
 * differ according to the message:
 *
 * SUSPEND	Quiesce, enter a low power device state appropriate for
 * 		the upcoming system state (such as PCI_D3hot), and enable
 * 		wakeup events as appropriate.
 *
 * HIBERNATE	Enter a low power device state appropriate for the hibernation
 * 		state (eg. ACPI S4) and enable wakeup events as appropriate.
 *
 * FREEZE	Quiesce operations so that a consistent image can be saved;
 * 		but do NOT otherwise enter a low power device state, and do
 * 		NOT emit system wakeup events.
 *
 * PRETHAW	Quiesce as if for FREEZE; additionally, prepare for restoring
 * 		the system from a snapshot taken after an earlier FREEZE.
 * 		Some drivers will need to reset their hardware state instead
 * 		of preserving it, to ensure that it's never mistaken for the
 * 		state which that earlier snapshot had set up.
 *
 * A minimally power-aware driver treats all messages as SUSPEND, fully
 * reinitializes its device during resume() -- whether or not it was reset
 * during the suspend/resume cycle -- and can't issue wakeup events.
 *
 * More power-aware drivers may also use low power states at runtime as
 * well as during system sleep states like PM_SUSPEND_STANDBY.  They may
 * be able to use wakeup events to exit from runtime low-power states,
 * or from system low-power states such as standby or suspend-to-RAM.
 */

#ifdef CONFIG_PM_SLEEP
extern void device_pm_lock(void);
extern int sysdev_resume(void);
extern void dpm_resume_noirq(pm_message_t state);
extern void dpm_resume_end(pm_message_t state);

extern void device_pm_unlock(void);
extern int sysdev_suspend(pm_message_t state);
extern int dpm_suspend_noirq(pm_message_t state);
extern int dpm_suspend_start(pm_message_t state);

extern void __suspend_report_result(const char *function, void *fn, int ret);

#define suspend_report_result(fn, ret)					\
	do {								\
		__suspend_report_result(__func__, fn, ret);		\
	} while (0)

extern void device_pm_wait_for_dev(struct device *sub, struct device *dev);

/* drivers/base/power/wakeup.c */
extern void pm_wakeup_event(struct device *dev, unsigned int msec);
extern void pm_stay_awake(struct device *dev);
extern void pm_relax(void);
#else /* !CONFIG_PM_SLEEP */

#define device_pm_lock() do {} while (0)
#define device_pm_unlock() do {} while (0)

static inline int dpm_suspend_start(pm_message_t state)
{
	return 0;
}

#define suspend_report_result(fn, ret)		do {} while (0)

static inline void device_pm_wait_for_dev(struct device *a, struct device *b) {}

static inline void pm_wakeup_event(struct device *dev, unsigned int msec) {}
static inline void pm_stay_awake(struct device *dev) {}
static inline void pm_relax(void) {}
#endif /* !CONFIG_PM_SLEEP */

/* How to reorder dpm_list after device_move() */
enum dpm_order {
	DPM_ORDER_NONE,
	DPM_ORDER_DEV_AFTER_PARENT,
	DPM_ORDER_PARENT_BEFORE_DEV,
	DPM_ORDER_DEV_LAST,
};

/*
 * Global Power Management flags
 * Used to keep APM and ACPI from both being active
 */
extern unsigned int	pm_flags;

#define PM_APM	1
#define PM_ACPI	2

#endif /* _LINUX_PM_H */
OpenPOWER on IntegriCloud