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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * pm.h - Power management interface
3 *
4 * Copyright (C) 2000 Andrew Henroid
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 */
20
21#ifndef _LINUX_PM_H
22#define _LINUX_PM_H
23
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include <linux/list.h>
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +020025#include <linux/workqueue.h>
26#include <linux/spinlock.h>
27#include <linux/wait.h>
28#include <linux/timer.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070029
30/*
Linus Torvalds1da177e2005-04-16 15:20:36 -070031 * Callbacks for platform drivers to implement.
32 */
33extern void (*pm_idle)(void);
34extern void (*pm_power_off)(void);
Rafael J. Wysockibd804eb2007-07-19 01:47:40 -070035extern void (*pm_power_off_prepare)(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070036
Linus Torvalds1da177e2005-04-16 15:20:36 -070037/*
38 * Device power management
39 */
40
41struct device;
42
Pavel Machekca078ba2005-09-03 15:56:57 -070043typedef struct pm_message {
44 int event;
45} pm_message_t;
Linus Torvalds1da177e2005-04-16 15:20:36 -070046
Rafael J. Wysocki1eede072008-05-20 23:00:01 +020047/**
Rafael J. Wysockiadf09492008-10-06 22:46:05 +020048 * struct dev_pm_ops - device PM callbacks
Rafael J. Wysocki1eede072008-05-20 23:00:01 +020049 *
David Brownell82bb67f2006-08-14 23:11:04 -070050 * Several driver power state transitions are externally visible, affecting
51 * the state of pending I/O queues and (for drivers that touch hardware)
52 * interrupts, wakeups, DMA, and other hardware state. There may also be
53 * internal transitions to various low power modes, which are transparent
54 * to the rest of the driver stack (such as a driver that's ON gating off
55 * clocks which are not in active use).
Linus Torvalds1da177e2005-04-16 15:20:36 -070056 *
Rafael J. Wysocki1eede072008-05-20 23:00:01 +020057 * The externally visible transitions are handled with the help of the following
58 * callbacks included in this structure:
59 *
60 * @prepare: Prepare the device for the upcoming transition, but do NOT change
61 * its hardware state. Prevent new children of the device from being
62 * registered after @prepare() returns (the driver's subsystem and
63 * generally the rest of the kernel is supposed to prevent new calls to the
64 * probe method from being made too once @prepare() has succeeded). If
65 * @prepare() detects a situation it cannot handle (e.g. registration of a
66 * child already in progress), it may return -EAGAIN, so that the PM core
67 * can execute it once again (e.g. after the new child has been registered)
68 * to recover from the race condition. This method is executed for all
69 * kinds of suspend transitions and is followed by one of the suspend
70 * callbacks: @suspend(), @freeze(), or @poweroff().
71 * The PM core executes @prepare() for all devices before starting to
72 * execute suspend callbacks for any of them, so drivers may assume all of
73 * the other devices to be present and functional while @prepare() is being
74 * executed. In particular, it is safe to make GFP_KERNEL memory
75 * allocations from within @prepare(). However, drivers may NOT assume
76 * anything about the availability of the user space at that time and it
77 * is not correct to request firmware from within @prepare() (it's too
78 * late to do that). [To work around this limitation, drivers may
79 * register suspend and hibernation notifiers that are executed before the
80 * freezing of tasks.]
81 *
82 * @complete: Undo the changes made by @prepare(). This method is executed for
83 * all kinds of resume transitions, following one of the resume callbacks:
84 * @resume(), @thaw(), @restore(). Also called if the state transition
85 * fails before the driver's suspend callback (@suspend(), @freeze(),
86 * @poweroff()) can be executed (e.g. if the suspend callback fails for one
87 * of the other devices that the PM core has unsuccessfully attempted to
88 * suspend earlier).
89 * The PM core executes @complete() after it has executed the appropriate
90 * resume callback for all devices.
91 *
92 * @suspend: Executed before putting the system into a sleep state in which the
93 * contents of main memory are preserved. Quiesce the device, put it into
94 * a low power state appropriate for the upcoming system state (such as
95 * PCI_D3hot), and enable wakeup events as appropriate.
96 *
97 * @resume: Executed after waking the system up from a sleep state in which the
98 * contents of main memory were preserved. Put the device into the
99 * appropriate state, according to the information saved in memory by the
100 * preceding @suspend(). The driver starts working again, responding to
101 * hardware events and software requests. The hardware may have gone
102 * through a power-off reset, or it may have maintained state from the
103 * previous suspend() which the driver may rely on while resuming. On most
104 * platforms, there are no restrictions on availability of resources like
105 * clocks during @resume().
106 *
107 * @freeze: Hibernation-specific, executed before creating a hibernation image.
108 * Quiesce operations so that a consistent image can be created, but do NOT
109 * otherwise put the device into a low power device state and do NOT emit
110 * system wakeup events. Save in main memory the device settings to be
111 * used by @restore() during the subsequent resume from hibernation or by
112 * the subsequent @thaw(), if the creation of the image or the restoration
113 * of main memory contents from it fails.
114 *
115 * @thaw: Hibernation-specific, executed after creating a hibernation image OR
116 * if the creation of the image fails. Also executed after a failing
117 * attempt to restore the contents of main memory from such an image.
118 * Undo the changes made by the preceding @freeze(), so the device can be
119 * operated in the same way as immediately before the call to @freeze().
120 *
121 * @poweroff: Hibernation-specific, executed after saving a hibernation image.
122 * Quiesce the device, put it into a low power state appropriate for the
123 * upcoming system state (such as PCI_D3hot), and enable wakeup events as
124 * appropriate.
125 *
126 * @restore: Hibernation-specific, executed after restoring the contents of main
127 * memory from a hibernation image. Driver starts working again,
128 * responding to hardware events and software requests. Drivers may NOT
129 * make ANY assumptions about the hardware state right prior to @restore().
130 * On most platforms, there are no restrictions on availability of
131 * resources like clocks during @restore().
132 *
Rafael J. Wysocki1eede072008-05-20 23:00:01 +0200133 * @suspend_noirq: Complete the operations of ->suspend() by carrying out any
134 * actions required for suspending the device that need interrupts to be
135 * disabled
136 *
137 * @resume_noirq: Prepare for the execution of ->resume() by carrying out any
138 * actions required for resuming the device that need interrupts to be
139 * disabled
140 *
141 * @freeze_noirq: Complete the operations of ->freeze() by carrying out any
142 * actions required for freezing the device that need interrupts to be
143 * disabled
144 *
145 * @thaw_noirq: Prepare for the execution of ->thaw() by carrying out any
146 * actions required for thawing the device that need interrupts to be
147 * disabled
148 *
149 * @poweroff_noirq: Complete the operations of ->poweroff() by carrying out any
150 * actions required for handling the device that need interrupts to be
151 * disabled
152 *
153 * @restore_noirq: Prepare for the execution of ->restore() by carrying out any
154 * actions required for restoring the operations of the device that need
155 * interrupts to be disabled
156 *
Rafael J. Wysockiadf09492008-10-06 22:46:05 +0200157 * All of the above callbacks, except for @complete(), return error codes.
158 * However, the error codes returned by the resume operations, @resume(),
159 * @thaw(), @restore(), @resume_noirq(), @thaw_noirq(), and @restore_noirq() do
160 * not cause the PM core to abort the resume transition during which they are
161 * returned. The error codes returned in that cases are only printed by the PM
162 * core to the system logs for debugging purposes. Still, it is recommended
163 * that drivers only return error codes from their resume methods in case of an
164 * unrecoverable failure (i.e. when the device being handled refuses to resume
165 * and becomes unusable) to allow us to modify the PM core in the future, so
166 * that it can avoid attempting to handle devices that failed to resume and
167 * their children.
168 *
169 * It is allowed to unregister devices while the above callbacks are being
170 * executed. However, it is not allowed to unregister a device from within any
171 * of its own callbacks.
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200172 *
173 * There also are the following callbacks related to run-time power management
174 * of devices:
175 *
176 * @runtime_suspend: Prepare the device for a condition in which it won't be
177 * able to communicate with the CPU(s) and RAM due to power management.
178 * This need not mean that the device should be put into a low power state.
179 * For example, if the device is behind a link which is about to be turned
180 * off, the device may remain at full power. If the device does go to low
Rafael J. Wysocki7a1a8eb2009-12-03 21:19:18 +0100181 * power and is capable of generating run-time wake-up events, remote
182 * wake-up (i.e., a hardware mechanism allowing the device to request a
183 * change of its power state via a wake-up event, such as PCI PME) should
184 * be enabled for it.
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200185 *
186 * @runtime_resume: Put the device into the fully active state in response to a
187 * wake-up event generated by hardware or at the request of software. If
188 * necessary, put the device into the full power state and restore its
189 * registers, so that it is fully operational.
190 *
191 * @runtime_idle: Device appears to be inactive and it might be put into a low
192 * power state if all of the necessary conditions are satisfied. Check
193 * these conditions and handle the device as appropriate, possibly queueing
194 * a suspend request for it. The return value is ignored by the PM core.
Rafael J. Wysocki1eede072008-05-20 23:00:01 +0200195 */
196
Rafael J. Wysockiadf09492008-10-06 22:46:05 +0200197struct dev_pm_ops {
198 int (*prepare)(struct device *dev);
199 void (*complete)(struct device *dev);
200 int (*suspend)(struct device *dev);
201 int (*resume)(struct device *dev);
202 int (*freeze)(struct device *dev);
203 int (*thaw)(struct device *dev);
204 int (*poweroff)(struct device *dev);
205 int (*restore)(struct device *dev);
Rafael J. Wysocki1eede072008-05-20 23:00:01 +0200206 int (*suspend_noirq)(struct device *dev);
207 int (*resume_noirq)(struct device *dev);
208 int (*freeze_noirq)(struct device *dev);
209 int (*thaw_noirq)(struct device *dev);
210 int (*poweroff_noirq)(struct device *dev);
211 int (*restore_noirq)(struct device *dev);
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200212 int (*runtime_suspend)(struct device *dev);
213 int (*runtime_resume)(struct device *dev);
214 int (*runtime_idle)(struct device *dev);
Rafael J. Wysocki1eede072008-05-20 23:00:01 +0200215};
216
Albin Tonnerre9d62ec62009-08-05 23:59:59 +0200217/*
218 * Use this if you want to use the same suspend and resume callbacks for suspend
219 * to RAM and hibernation.
220 */
221#define SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn) \
Alexey Dobriyan47145212009-12-14 18:00:08 -0800222const struct dev_pm_ops name = { \
Albin Tonnerre9d62ec62009-08-05 23:59:59 +0200223 .suspend = suspend_fn, \
224 .resume = resume_fn, \
225 .freeze = suspend_fn, \
226 .thaw = resume_fn, \
227 .poweroff = suspend_fn, \
228 .restore = resume_fn, \
229}
230
Rafael J. Wysocki1eede072008-05-20 23:00:01 +0200231/**
232 * PM_EVENT_ messages
233 *
234 * The following PM_EVENT_ messages are defined for the internal use of the PM
235 * core, in order to provide a mechanism allowing the high level suspend and
236 * hibernation code to convey the necessary information to the device PM core
237 * code:
238 *
239 * ON No transition.
240 *
241 * FREEZE System is going to hibernate, call ->prepare() and ->freeze()
242 * for all devices.
243 *
244 * SUSPEND System is going to suspend, call ->prepare() and ->suspend()
245 * for all devices.
246 *
247 * HIBERNATE Hibernation image has been saved, call ->prepare() and
248 * ->poweroff() for all devices.
249 *
250 * QUIESCE Contents of main memory are going to be restored from a (loaded)
251 * hibernation image, call ->prepare() and ->freeze() for all
252 * devices.
253 *
254 * RESUME System is resuming, call ->resume() and ->complete() for all
255 * devices.
256 *
257 * THAW Hibernation image has been created, call ->thaw() and
258 * ->complete() for all devices.
259 *
260 * RESTORE Contents of main memory have been restored from a hibernation
261 * image, call ->restore() and ->complete() for all devices.
262 *
263 * RECOVER Creation of a hibernation image or restoration of the main
264 * memory contents from a hibernation image has failed, call
265 * ->thaw() and ->complete() for all devices.
Alan Stern8111d1b2008-07-23 21:28:37 -0700266 *
267 * The following PM_EVENT_ messages are defined for internal use by
268 * kernel subsystems. They are never issued by the PM core.
269 *
270 * USER_SUSPEND Manual selective suspend was issued by userspace.
271 *
272 * USER_RESUME Manual selective resume was issued by userspace.
273 *
274 * REMOTE_WAKEUP Remote-wakeup request was received from the device.
275 *
276 * AUTO_SUSPEND Automatic (device idle) runtime suspend was
277 * initiated by the subsystem.
278 *
279 * AUTO_RESUME Automatic (device needed) runtime resume was
280 * requested by a driver.
Rafael J. Wysocki1eede072008-05-20 23:00:01 +0200281 */
282
283#define PM_EVENT_ON 0x0000
284#define PM_EVENT_FREEZE 0x0001
285#define PM_EVENT_SUSPEND 0x0002
286#define PM_EVENT_HIBERNATE 0x0004
287#define PM_EVENT_QUIESCE 0x0008
288#define PM_EVENT_RESUME 0x0010
289#define PM_EVENT_THAW 0x0020
290#define PM_EVENT_RESTORE 0x0040
291#define PM_EVENT_RECOVER 0x0080
Alan Stern8111d1b2008-07-23 21:28:37 -0700292#define PM_EVENT_USER 0x0100
293#define PM_EVENT_REMOTE 0x0200
294#define PM_EVENT_AUTO 0x0400
Rafael J. Wysocki1eede072008-05-20 23:00:01 +0200295
Alan Stern8111d1b2008-07-23 21:28:37 -0700296#define PM_EVENT_SLEEP (PM_EVENT_SUSPEND | PM_EVENT_HIBERNATE)
297#define PM_EVENT_USER_SUSPEND (PM_EVENT_USER | PM_EVENT_SUSPEND)
298#define PM_EVENT_USER_RESUME (PM_EVENT_USER | PM_EVENT_RESUME)
Alan Stern7f4f5d42008-11-17 11:14:19 -0500299#define PM_EVENT_REMOTE_RESUME (PM_EVENT_REMOTE | PM_EVENT_RESUME)
Alan Stern8111d1b2008-07-23 21:28:37 -0700300#define PM_EVENT_AUTO_SUSPEND (PM_EVENT_AUTO | PM_EVENT_SUSPEND)
301#define PM_EVENT_AUTO_RESUME (PM_EVENT_AUTO | PM_EVENT_RESUME)
Rafael J. Wysocki1eede072008-05-20 23:00:01 +0200302
Alan Stern8111d1b2008-07-23 21:28:37 -0700303#define PMSG_ON ((struct pm_message){ .event = PM_EVENT_ON, })
Rafael J. Wysocki1eede072008-05-20 23:00:01 +0200304#define PMSG_FREEZE ((struct pm_message){ .event = PM_EVENT_FREEZE, })
305#define PMSG_QUIESCE ((struct pm_message){ .event = PM_EVENT_QUIESCE, })
306#define PMSG_SUSPEND ((struct pm_message){ .event = PM_EVENT_SUSPEND, })
307#define PMSG_HIBERNATE ((struct pm_message){ .event = PM_EVENT_HIBERNATE, })
308#define PMSG_RESUME ((struct pm_message){ .event = PM_EVENT_RESUME, })
309#define PMSG_THAW ((struct pm_message){ .event = PM_EVENT_THAW, })
310#define PMSG_RESTORE ((struct pm_message){ .event = PM_EVENT_RESTORE, })
311#define PMSG_RECOVER ((struct pm_message){ .event = PM_EVENT_RECOVER, })
Alan Stern7f4f5d42008-11-17 11:14:19 -0500312#define PMSG_USER_SUSPEND ((struct pm_message) \
Alan Stern8111d1b2008-07-23 21:28:37 -0700313 { .event = PM_EVENT_USER_SUSPEND, })
Alan Stern7f4f5d42008-11-17 11:14:19 -0500314#define PMSG_USER_RESUME ((struct pm_message) \
Alan Stern8111d1b2008-07-23 21:28:37 -0700315 { .event = PM_EVENT_USER_RESUME, })
Alan Stern7f4f5d42008-11-17 11:14:19 -0500316#define PMSG_REMOTE_RESUME ((struct pm_message) \
Alan Stern8111d1b2008-07-23 21:28:37 -0700317 { .event = PM_EVENT_REMOTE_RESUME, })
Alan Stern7f4f5d42008-11-17 11:14:19 -0500318#define PMSG_AUTO_SUSPEND ((struct pm_message) \
Alan Stern8111d1b2008-07-23 21:28:37 -0700319 { .event = PM_EVENT_AUTO_SUSPEND, })
Alan Stern7f4f5d42008-11-17 11:14:19 -0500320#define PMSG_AUTO_RESUME ((struct pm_message) \
Alan Stern8111d1b2008-07-23 21:28:37 -0700321 { .event = PM_EVENT_AUTO_RESUME, })
Rafael J. Wysocki1eede072008-05-20 23:00:01 +0200322
323/**
324 * Device power management states
325 *
326 * These state labels are used internally by the PM core to indicate the current
327 * status of a device with respect to the PM core operations.
328 *
329 * DPM_ON Device is regarded as operational. Set this way
330 * initially and when ->complete() is about to be called.
331 * Also set when ->prepare() fails.
332 *
333 * DPM_PREPARING Device is going to be prepared for a PM transition. Set
334 * when ->prepare() is about to be called.
335 *
336 * DPM_RESUMING Device is going to be resumed. Set when ->resume(),
337 * ->thaw(), or ->restore() is about to be called.
338 *
339 * DPM_SUSPENDING Device has been prepared for a power transition. Set
340 * when ->prepare() has just succeeded.
341 *
342 * DPM_OFF Device is regarded as inactive. Set immediately after
343 * ->suspend(), ->freeze(), or ->poweroff() has succeeded.
344 * Also set when ->resume()_noirq, ->thaw_noirq(), or
345 * ->restore_noirq() is about to be called.
346 *
347 * DPM_OFF_IRQ Device is in a "deep sleep". Set immediately after
348 * ->suspend_noirq(), ->freeze_noirq(), or
349 * ->poweroff_noirq() has just succeeded.
350 */
351
352enum dpm_state {
353 DPM_INVALID,
354 DPM_ON,
355 DPM_PREPARING,
356 DPM_RESUMING,
357 DPM_SUSPENDING,
358 DPM_OFF,
359 DPM_OFF_IRQ,
360};
361
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200362/**
363 * Device run-time power management status.
364 *
365 * These status labels are used internally by the PM core to indicate the
366 * current status of a device with respect to the PM core operations. They do
367 * not reflect the actual power state of the device or its status as seen by the
368 * driver.
369 *
370 * RPM_ACTIVE Device is fully operational. Indicates that the device
371 * bus type's ->runtime_resume() callback has completed
372 * successfully.
373 *
374 * RPM_SUSPENDED Device bus type's ->runtime_suspend() callback has
375 * completed successfully. The device is regarded as
376 * suspended.
377 *
378 * RPM_RESUMING Device bus type's ->runtime_resume() callback is being
379 * executed.
380 *
381 * RPM_SUSPENDING Device bus type's ->runtime_suspend() callback is being
382 * executed.
383 */
384
385enum rpm_status {
386 RPM_ACTIVE = 0,
387 RPM_RESUMING,
388 RPM_SUSPENDED,
389 RPM_SUSPENDING,
390};
391
392/**
393 * Device run-time power management request types.
394 *
395 * RPM_REQ_NONE Do nothing.
396 *
397 * RPM_REQ_IDLE Run the device bus type's ->runtime_idle() callback
398 *
399 * RPM_REQ_SUSPEND Run the device bus type's ->runtime_suspend() callback
400 *
401 * RPM_REQ_RESUME Run the device bus type's ->runtime_resume() callback
402 */
403
404enum rpm_request {
405 RPM_REQ_NONE = 0,
406 RPM_REQ_IDLE,
407 RPM_REQ_SUSPEND,
408 RPM_REQ_RESUME,
409};
410
Rafael J. Wysocki1eede072008-05-20 23:00:01 +0200411struct dev_pm_info {
412 pm_message_t power_state;
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200413 unsigned int can_wakeup:1;
414 unsigned int should_wakeup:1;
Rafael J. Wysocki1eede072008-05-20 23:00:01 +0200415 enum dpm_state status; /* Owned by the PM core */
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200416#ifdef CONFIG_PM_SLEEP
Rafael J. Wysocki1eede072008-05-20 23:00:01 +0200417 struct list_head entry;
418#endif
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200419#ifdef CONFIG_PM_RUNTIME
420 struct timer_list suspend_timer;
421 unsigned long timer_expires;
422 struct work_struct work;
423 wait_queue_head_t wait_queue;
424 spinlock_t lock;
425 atomic_t usage_count;
426 atomic_t child_count;
427 unsigned int disable_depth:3;
428 unsigned int ignore_children:1;
429 unsigned int idle_notification:1;
430 unsigned int request_pending:1;
431 unsigned int deferred_resume:1;
Rafael J. Wysocki7a1a8eb2009-12-03 21:19:18 +0100432 unsigned int run_wake:1;
Rafael J. Wysocki5e928f72009-08-18 23:38:32 +0200433 enum rpm_request request;
434 enum rpm_status runtime_status;
435 int runtime_error;
436#endif
Rafael J. Wysocki1eede072008-05-20 23:00:01 +0200437};
438
439/*
440 * The PM_EVENT_ messages are also used by drivers implementing the legacy
441 * suspend framework, based on the ->suspend() and ->resume() callbacks common
442 * for suspend and hibernation transitions, according to the rules below.
443 */
444
445/* Necessary, because several drivers use PM_EVENT_PRETHAW */
446#define PM_EVENT_PRETHAW PM_EVENT_QUIESCE
447
448/*
David Brownell82bb67f2006-08-14 23:11:04 -0700449 * One transition is triggered by resume(), after a suspend() call; the
450 * message is implicit:
451 *
452 * ON Driver starts working again, responding to hardware events
453 * and software requests. The hardware may have gone through
454 * a power-off reset, or it may have maintained state from the
455 * previous suspend() which the driver will rely on while
456 * resuming. On most platforms, there are no restrictions on
457 * availability of resources like clocks during resume().
458 *
459 * Other transitions are triggered by messages sent using suspend(). All
460 * these transitions quiesce the driver, so that I/O queues are inactive.
461 * That commonly entails turning off IRQs and DMA; there may be rules
462 * about how to quiesce that are specific to the bus or the device's type.
463 * (For example, network drivers mark the link state.) Other details may
464 * differ according to the message:
465 *
466 * SUSPEND Quiesce, enter a low power device state appropriate for
467 * the upcoming system state (such as PCI_D3hot), and enable
468 * wakeup events as appropriate.
469 *
Rafael J. Wysocki3a2d5b72008-02-23 19:13:25 +0100470 * HIBERNATE Enter a low power device state appropriate for the hibernation
471 * state (eg. ACPI S4) and enable wakeup events as appropriate.
472 *
David Brownell82bb67f2006-08-14 23:11:04 -0700473 * FREEZE Quiesce operations so that a consistent image can be saved;
474 * but do NOT otherwise enter a low power device state, and do
475 * NOT emit system wakeup events.
476 *
477 * PRETHAW Quiesce as if for FREEZE; additionally, prepare for restoring
478 * the system from a snapshot taken after an earlier FREEZE.
479 * Some drivers will need to reset their hardware state instead
480 * of preserving it, to ensure that it's never mistaken for the
481 * state which that earlier snapshot had set up.
482 *
483 * A minimally power-aware driver treats all messages as SUSPEND, fully
484 * reinitializes its device during resume() -- whether or not it was reset
485 * during the suspend/resume cycle -- and can't issue wakeup events.
486 *
487 * More power-aware drivers may also use low power states at runtime as
488 * well as during system sleep states like PM_SUSPEND_STANDBY. They may
489 * be able to use wakeup events to exit from runtime low-power states,
490 * or from system low-power states such as standby or suspend-to-RAM.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700491 */
492
Rafael J. Wysocki296699d2007-07-29 23:27:18 +0200493#ifdef CONFIG_PM_SLEEP
Rafael J. Wysocki1eede072008-05-20 23:00:01 +0200494extern void device_pm_lock(void);
Rafael J. Wysocki770824b2009-02-22 18:38:50 +0100495extern int sysdev_resume(void);
Alan Sternd1616302009-05-24 22:05:42 +0200496extern void dpm_resume_noirq(pm_message_t state);
497extern void dpm_resume_end(pm_message_t state);
Rafael J. Wysocki1eede072008-05-20 23:00:01 +0200498
499extern void device_pm_unlock(void);
Rafael J. Wysocki770824b2009-02-22 18:38:50 +0100500extern int sysdev_suspend(pm_message_t state);
Alan Sternd1616302009-05-24 22:05:42 +0200501extern int dpm_suspend_noirq(pm_message_t state);
502extern int dpm_suspend_start(pm_message_t state);
David Brownell0ac85242005-09-12 19:39:34 -0700503
Andrew Morton02669492006-03-23 01:38:34 -0800504extern void __suspend_report_result(const char *function, void *fn, int ret);
505
506#define suspend_report_result(fn, ret) \
507 do { \
Harvey Harrisond5c003b2008-10-15 22:01:24 -0700508 __suspend_report_result(__func__, fn, ret); \
Andrew Morton02669492006-03-23 01:38:34 -0800509 } while (0)
Andrew Morton9a7834d2005-10-23 23:02:20 -0700510
Alan Sternd288e472008-03-19 22:37:42 +0100511#else /* !CONFIG_PM_SLEEP */
512
Cornelia Huckffa6a702009-03-04 12:44:00 +0100513#define device_pm_lock() do {} while (0)
514#define device_pm_unlock() do {} while (0)
515
Alan Sternd1616302009-05-24 22:05:42 +0200516static inline int dpm_suspend_start(pm_message_t state)
Alan Sternd288e472008-03-19 22:37:42 +0100517{
518 return 0;
519}
520
Alan Stern9a3df1f2008-03-19 22:39:13 +0100521#define suspend_report_result(fn, ret) do {} while (0)
Alan Sternd288e472008-03-19 22:37:42 +0100522
523#endif /* !CONFIG_PM_SLEEP */
524
Cornelia Huckffa6a702009-03-04 12:44:00 +0100525/* How to reorder dpm_list after device_move() */
526enum dpm_order {
527 DPM_ORDER_NONE,
528 DPM_ORDER_DEV_AFTER_PARENT,
529 DPM_ORDER_PARENT_BEFORE_DEV,
530 DPM_ORDER_DEV_LAST,
531};
532
Len Brown9f9adec2007-12-13 17:38:03 -0500533/*
534 * Global Power Management flags
535 * Used to keep APM and ACPI from both being active
536 */
537extern unsigned int pm_flags;
538
539#define PM_APM 1
540#define PM_ACPI 2
541
Linus Torvalds1da177e2005-04-16 15:20:36 -0700542#endif /* _LINUX_PM_H */