1 /*
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
24 #include <linux/list.h>
25 #include <linux/workqueue.h>
26 #include <linux/spinlock.h>
27 #include <linux/wait.h>
28 #include <linux/timer.h>
29 #include <linux/completion.h>
30
31 /*
32 * Callbacks for platform drivers to implement.
33 */
34 extern void (*pm_idle)(void);
35 extern void (*pm_power_off)(void);
36 extern void (*pm_power_off_prepare)(void);
37
38 /*
39 * Device power management
40 */
41
42 struct device;
43
44 #ifdef CONFIG_PM
45 extern const char power_group_name[]; /* = "power" */
46 #else
47 #define power_group_name NULL
48 #endif
49
50 typedef struct pm_message {
51 int event;
52 } pm_message_t;
53
54 /**
55 * struct dev_pm_ops - device PM callbacks
56 *
57 * Several device power state transitions are externally visible, affecting
58 * the state of pending I/O queues and (for drivers that touch hardware)
59 * interrupts, wakeups, DMA, and other hardware state. There may also be
60 * internal transitions to various low-power modes which are transparent
61 * to the rest of the driver stack (such as a driver that's ON gating off
62 * clocks which are not in active use).
63 *
64 * The externally visible transitions are handled with the help of callbacks
65 * included in this structure in such a way that two levels of callbacks are
66 * involved. First, the PM core executes callbacks provided by PM domains,
67 * device types, classes and bus types. They are the subsystem-level callbacks
68 * supposed to execute callbacks provided by device drivers, although they may
69 * choose not to do that. If the driver callbacks are executed, they have to
70 * collaborate with the subsystem-level callbacks to achieve the goals
71 * appropriate for the given system transition, given transition phase and the
72 * subsystem the device belongs to.
73 *
74 * @prepare: The principal role of this callback is to prevent new children of
75 * the device from being registered after it has returned (the driver's
76 * subsystem and generally the rest of the kernel is supposed to prevent
77 * new calls to the probe method from being made too once @prepare() has
78 * succeeded). If @prepare() detects a situation it cannot handle (e.g.
79 * registration of a child already in progress), it may return -EAGAIN, so
80 * that the PM core can execute it once again (e.g. after a new child has
81 * been registered) to recover from the race condition.
82 * This method is executed for all kinds of suspend transitions and is
83 * followed by one of the suspend callbacks: @suspend(), @freeze(), or
84 * @poweroff(). The PM core executes subsystem-level @prepare() for all
85 * devices before starting to invoke suspend callbacks for any of them, so
86 * generally devices may be assumed to be functional or to respond to
87 * runtime resume requests while @prepare() is being executed. However,
88 * device drivers may NOT assume anything about the availability of user
89 * space at that time and it is NOT valid to request firmware from within
90 * @prepare() (it's too late to do that). It also is NOT valid to allocate
91 * substantial amounts of memory from @prepare() in the GFP_KERNEL mode.
92 * [To work around these limitations, drivers may register suspend and
93 * hibernation notifiers to be executed before the freezing of tasks.]
94 *
95 * @complete: Undo the changes made by @prepare(). This method is executed for
96 * all kinds of resume transitions, following one of the resume callbacks:
97 * @resume(), @thaw(), @restore(). Also called if the state transition
98 * fails before the driver's suspend callback: @suspend(), @freeze() or
99 * @poweroff(), can be executed (e.g. if the suspend callback fails for one
100 * of the other devices that the PM core has unsuccessfully attempted to
101 * suspend earlier).
102 * The PM core executes subsystem-level @complete() after it has executed
103 * the appropriate resume callbacks for all devices.
104 *
105 * @suspend: Executed before putting the system into a sleep state in which the
106 * contents of main memory are preserved. The exact action to perform
107 * depends on the device's subsystem (PM domain, device type, class or bus
108 * type), but generally the device must be quiescent after subsystem-level
109 * @suspend() has returned, so that it doesn't do any I/O or DMA.
110 * Subsystem-level @suspend() is executed for all devices after invoking
111 * subsystem-level @prepare() for all of them.
112 *
113 * @resume: Executed after waking the system up from a sleep state in which the
114 * contents of main memory were preserved. The exact action to perform
115 * depends on the device's subsystem, but generally the driver is expected
116 * to start working again, responding to hardware events and software
117 * requests (the device itself may be left in a low-power state, waiting
118 * for a runtime resume to occur). The state of the device at the time its
119 * driver's @resume() callback is run depends on the platform and subsystem
120 * the device belongs to. On most platforms, there are no restrictions on
121 * availability of resources like clocks during @resume().
122 * Subsystem-level @resume() is executed for all devices after invoking
123 * subsystem-level @resume_noirq() for all of them.
124 *
125 * @freeze: Hibernation-specific, executed before creating a hibernation image.
126 * Analogous to @suspend(), but it should not enable the device to signal
127 * wakeup events or change its power state. The majority of subsystems
128 * (with the notable exception of the PCI bus type) expect the driver-level
129 * @freeze() to save the device settings in memory to be used by @restore()
130 * during the subsequent resume from hibernation.
131 * Subsystem-level @freeze() is executed for all devices after invoking
132 * subsystem-level @prepare() for all of them.
133 *
134 * @thaw: Hibernation-specific, executed after creating a hibernation image OR
135 * if the creation of an image has failed. Also executed after a failing
136 * attempt to restore the contents of main memory from such an image.
137 * Undo the changes made by the preceding @freeze(), so the device can be
138 * operated in the same way as immediately before the call to @freeze().
139 * Subsystem-level @thaw() is executed for all devices after invoking
140 * subsystem-level @thaw_noirq() for all of them. It also may be executed
141 * directly after @freeze() in case of a transition error.
142 *
143 * @poweroff: Hibernation-specific, executed after saving a hibernation image.
144 * Analogous to @suspend(), but it need not save the device's settings in
145 * memory.
146 * Subsystem-level @poweroff() is executed for all devices after invoking
147 * subsystem-level @prepare() for all of them.
148 *
149 * @restore: Hibernation-specific, executed after restoring the contents of main
150 * memory from a hibernation image, analogous to @resume().
151 *
152 * @suspend_noirq: Complete the actions started by @suspend(). Carry out any
153 * additional operations required for suspending the device that might be
154 * racing with its driver's interrupt handler, which is guaranteed not to
155 * run while @suspend_noirq() is being executed.
156 * It generally is expected that the device will be in a low-power state
157 * (appropriate for the target system sleep state) after subsystem-level
158 * @suspend_noirq() has returned successfully. If the device can generate
159 * system wakeup signals and is enabled to wake up the system, it should be
160 * configured to do so at that time. However, depending on the platform
161 * and device's subsystem, @suspend() may be allowed to put the device into
162 * the low-power state and configure it to generate wakeup signals, in
163 * which case it generally is not necessary to define @suspend_noirq().
164 *
165 * @resume_noirq: Prepare for the execution of @resume() by carrying out any
166 * operations required for resuming the device that might be racing with
167 * its driver's interrupt handler, which is guaranteed not to run while
168 * @resume_noirq() is being executed.
169 *
170 * @freeze_noirq: Complete the actions started by @freeze(). Carry out any
171 * additional operations required for freezing the device that might be
172 * racing with its driver's interrupt handler, which is guaranteed not to
173 * run while @freeze_noirq() is being executed.
174 * The power state of the device should not be changed by either @freeze()
175 * or @freeze_noirq() and it should not be configured to signal system
176 * wakeup by any of these callbacks.
177 *
178 * @thaw_noirq: Prepare for the execution of @thaw() by carrying out any
179 * operations required for thawing the device that might be racing with its
180 * driver's interrupt handler, which is guaranteed not to run while
181 * @thaw_noirq() is being executed.
182 *
183 * @poweroff_noirq: Complete the actions started by @poweroff(). Analogous to
184 * @suspend_noirq(), but it need not save the device's settings in memory.
185 *
186 * @restore_noirq: Prepare for the execution of @restore() by carrying out any
187 * operations required for thawing the device that might be racing with its
188 * driver's interrupt handler, which is guaranteed not to run while
189 * @restore_noirq() is being executed. Analogous to @resume_noirq().
190 *
191 * All of the above callbacks, except for @complete(), return error codes.
192 * However, the error codes returned by the resume operations, @resume(),
193 * @thaw(), @restore(), @resume_noirq(), @thaw_noirq(), and @restore_noirq(), do
194 * not cause the PM core to abort the resume transition during which they are
195 * returned. The error codes returned in those cases are only printed by the PM
196 * core to the system logs for debugging purposes. Still, it is recommended
197 * that drivers only return error codes from their resume methods in case of an
198 * unrecoverable failure (i.e. when the device being handled refuses to resume
199 * and becomes unusable) to allow us to modify the PM core in the future, so
200 * that it can avoid attempting to handle devices that failed to resume and
201 * their children.
202 *
203 * It is allowed to unregister devices while the above callbacks are being
204 * executed. However, a callback routine must NOT try to unregister the device
205 * it was called for, although it may unregister children of that device (for
206 * example, if it detects that a child was unplugged while the system was
207 * asleep).
208 *
209 * Refer to Documentation/power/devices.txt for more information about the role
210 * of the above callbacks in the system suspend process.
211 *
212 * There also are callbacks related to runtime power management of devices.
213 * Again, these callbacks are executed by the PM core only for subsystems
214 * (PM domains, device types, classes and bus types) and the subsystem-level
215 * callbacks are supposed to invoke the driver callbacks. Moreover, the exact
216 * actions to be performed by a device driver's callbacks generally depend on
217 * the platform and subsystem the device belongs to.
218 *
219 * @runtime_suspend: Prepare the device for a condition in which it won't be
220 * able to communicate with the CPU(s) and RAM due to power management.
221 * This need not mean that the device should be put into a low-power state.
222 * For example, if the device is behind a link which is about to be turned
223 * off, the device may remain at full power. If the device does go to low
224 * power and is capable of generating runtime wakeup events, remote wakeup
225 * (i.e., a hardware mechanism allowing the device to request a change of
226 * its power state via an interrupt) should be enabled for it.
227 *
228 * @runtime_resume: Put the device into the fully active state in response to a
229 * wakeup event generated by hardware or at the request of software. If
230 * necessary, put the device into the full-power state and restore its
231 * registers, so that it is fully operational.
232 *
233 * @runtime_idle: Device appears to be inactive and it might be put into a
234 * low-power state if all of the necessary conditions are satisfied. Check
235 * these conditions and handle the device as appropriate, possibly queueing
236 * a suspend request for it. The return value is ignored by the PM core.
237 *
238 * Refer to Documentation/power/runtime_pm.txt for more information about the
239 * role of the above callbacks in device runtime power management.
240 *
241 */
242
243 struct dev_pm_ops {
244 int (*prepare)(struct device *dev);
245 void (*complete)(struct device *dev);
246 int (*suspend)(struct device *dev);
247 int (*resume)(struct device *dev);
248 int (*freeze)(struct device *dev);
249 int (*thaw)(struct device *dev);
250 int (*poweroff)(struct device *dev);
251 int (*restore)(struct device *dev);
252 int (*suspend_noirq)(struct device *dev);
253 int (*resume_noirq)(struct device *dev);
254 int (*freeze_noirq)(struct device *dev);
255 int (*thaw_noirq)(struct device *dev);
256 int (*poweroff_noirq)(struct device *dev);
257 int (*restore_noirq)(struct device *dev);
258 int (*runtime_suspend)(struct device *dev);
259 int (*runtime_resume)(struct device *dev);
260 int (*runtime_idle)(struct device *dev);
261 };
262
263 #ifdef CONFIG_PM_SLEEP
264 #define SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
265 .suspend = suspend_fn, \
266 .resume = resume_fn, \
267 .freeze = suspend_fn, \
268 .thaw = resume_fn, \
269 .poweroff = suspend_fn, \
270 .restore = resume_fn,
271 #else
272 #define SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn)
273 #endif
274
275 #ifdef CONFIG_PM_RUNTIME
276 #define SET_RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn) \
277 .runtime_suspend = suspend_fn, \
278 .runtime_resume = resume_fn, \
279 .runtime_idle = idle_fn,
280 #else
281 #define SET_RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn)
282 #endif
283
284 /*
285 * Use this if you want to use the same suspend and resume callbacks for suspend
286 * to RAM and hibernation.
287 */
288 #define SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn) \
289 const struct dev_pm_ops name = { \
290 SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
291 }
292
293 /*
294 * Use this for defining a set of PM operations to be used in all situations
295 * (sustem suspend, hibernation or runtime PM).
296 */
297 #define UNIVERSAL_DEV_PM_OPS(name, suspend_fn, resume_fn, idle_fn) \
298 const struct dev_pm_ops name = { \
299 SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
300 SET_RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn) \
301 }
302
303 /**
304 * PM_EVENT_ messages
305 *
306 * The following PM_EVENT_ messages are defined for the internal use of the PM
307 * core, in order to provide a mechanism allowing the high level suspend and
308 * hibernation code to convey the necessary information to the device PM core
309 * code:
310 *
311 * ON No transition.
312 *
313 * FREEZE System is going to hibernate, call ->prepare() and ->freeze()
314 * for all devices.
315 *
316 * SUSPEND System is going to suspend, call ->prepare() and ->suspend()
317 * for all devices.
318 *
319 * HIBERNATE Hibernation image has been saved, call ->prepare() and
320 * ->poweroff() for all devices.
321 *
322 * QUIESCE Contents of main memory are going to be restored from a (loaded)
323 * hibernation image, call ->prepare() and ->freeze() for all
324 * devices.
325 *
326 * RESUME System is resuming, call ->resume() and ->complete() for all
327 * devices.
328 *
329 * THAW Hibernation image has been created, call ->thaw() and
330 * ->complete() for all devices.
331 *
332 * RESTORE Contents of main memory have been restored from a hibernation
333 * image, call ->restore() and ->complete() for all devices.
334 *
335 * RECOVER Creation of a hibernation image or restoration of the main
336 * memory contents from a hibernation image has failed, call
337 * ->thaw() and ->complete() for all devices.
338 *
339 * The following PM_EVENT_ messages are defined for internal use by
340 * kernel subsystems. They are never issued by the PM core.
341 *
342 * USER_SUSPEND Manual selective suspend was issued by userspace.
343 *
344 * USER_RESUME Manual selective resume was issued by userspace.
345 *
346 * REMOTE_WAKEUP Remote-wakeup request was received from the device.
347 *
348 * AUTO_SUSPEND Automatic (device idle) runtime suspend was
349 * initiated by the subsystem.
350 *
351 * AUTO_RESUME Automatic (device needed) runtime resume was
352 * requested by a driver.
353 */
354
355 #define PM_EVENT_INVALID (-1)
356 #define PM_EVENT_ON 0x0000
357 #define PM_EVENT_FREEZE 0x0001
358 #define PM_EVENT_SUSPEND 0x0002
359 #define PM_EVENT_HIBERNATE 0x0004
360 #define PM_EVENT_QUIESCE 0x0008
361 #define PM_EVENT_RESUME 0x0010
362 #define PM_EVENT_THAW 0x0020
363 #define PM_EVENT_RESTORE 0x0040
364 #define PM_EVENT_RECOVER 0x0080
365 #define PM_EVENT_USER 0x0100
366 #define PM_EVENT_REMOTE 0x0200
367 #define PM_EVENT_AUTO 0x0400
368
369 #define PM_EVENT_SLEEP (PM_EVENT_SUSPEND | PM_EVENT_HIBERNATE)
370 #define PM_EVENT_USER_SUSPEND (PM_EVENT_USER | PM_EVENT_SUSPEND)
371 #define PM_EVENT_USER_RESUME (PM_EVENT_USER | PM_EVENT_RESUME)
372 #define PM_EVENT_REMOTE_RESUME (PM_EVENT_REMOTE | PM_EVENT_RESUME)
373 #define PM_EVENT_AUTO_SUSPEND (PM_EVENT_AUTO | PM_EVENT_SUSPEND)
374 #define PM_EVENT_AUTO_RESUME (PM_EVENT_AUTO | PM_EVENT_RESUME)
375
376 #define PMSG_INVALID ((struct pm_message){ .event = PM_EVENT_INVALID, })
377 #define PMSG_ON ((struct pm_message){ .event = PM_EVENT_ON, })
378 #define PMSG_FREEZE ((struct pm_message){ .event = PM_EVENT_FREEZE, })
379 #define PMSG_QUIESCE ((struct pm_message){ .event = PM_EVENT_QUIESCE, })
380 #define PMSG_SUSPEND ((struct pm_message){ .event = PM_EVENT_SUSPEND, })
381 #define PMSG_HIBERNATE ((struct pm_message){ .event = PM_EVENT_HIBERNATE, })
382 #define PMSG_RESUME ((struct pm_message){ .event = PM_EVENT_RESUME, })
383 #define PMSG_THAW ((struct pm_message){ .event = PM_EVENT_THAW, })
384 #define PMSG_RESTORE ((struct pm_message){ .event = PM_EVENT_RESTORE, })
385 #define PMSG_RECOVER ((struct pm_message){ .event = PM_EVENT_RECOVER, })
386 #define PMSG_USER_SUSPEND ((struct pm_message) \
387 { .event = PM_EVENT_USER_SUSPEND, })
388 #define PMSG_USER_RESUME ((struct pm_message) \
389 { .event = PM_EVENT_USER_RESUME, })
390 #define PMSG_REMOTE_RESUME ((struct pm_message) \
391 { .event = PM_EVENT_REMOTE_RESUME, })
392 #define PMSG_AUTO_SUSPEND ((struct pm_message) \
393 { .event = PM_EVENT_AUTO_SUSPEND, })
394 #define PMSG_AUTO_RESUME ((struct pm_message) \
395 { .event = PM_EVENT_AUTO_RESUME, })
396
397 #define PMSG_IS_AUTO(msg) (((msg).event & PM_EVENT_AUTO) != 0)
398
399 /**
400 * Device run-time power management status.
401 *
402 * These status labels are used internally by the PM core to indicate the
403 * current status of a device with respect to the PM core operations. They do
404 * not reflect the actual power state of the device or its status as seen by the
405 * driver.
406 *
407 * RPM_ACTIVE Device is fully operational. Indicates that the device
408 * bus type's ->runtime_resume() callback has completed
409 * successfully.
410 *
411 * RPM_SUSPENDED Device bus type's ->runtime_suspend() callback has
412 * completed successfully. The device is regarded as
413 * suspended.
414 *
415 * RPM_RESUMING Device bus type's ->runtime_resume() callback is being
416 * executed.
417 *
418 * RPM_SUSPENDING Device bus type's ->runtime_suspend() callback is being
419 * executed.
420 */
421
422 enum rpm_status {
423 RPM_ACTIVE = 0,
424 RPM_RESUMING,
425 RPM_SUSPENDED,
426 RPM_SUSPENDING,
427 };
428
429 /**
430 * Device run-time power management request types.
431 *
432 * RPM_REQ_NONE Do nothing.
433 *
434 * RPM_REQ_IDLE Run the device bus type's ->runtime_idle() callback
435 *
436 * RPM_REQ_SUSPEND Run the device bus type's ->runtime_suspend() callback
437 *
438 * RPM_REQ_AUTOSUSPEND Same as RPM_REQ_SUSPEND, but not until the device has
439 * been inactive for as long as power.autosuspend_delay
440 *
441 * RPM_REQ_RESUME Run the device bus type's ->runtime_resume() callback
442 */
443
444 enum rpm_request {
445 RPM_REQ_NONE = 0,
446 RPM_REQ_IDLE,
447 RPM_REQ_SUSPEND,
448 RPM_REQ_AUTOSUSPEND,
449 RPM_REQ_RESUME,
450 };
451
452 struct wakeup_source;
453
454 struct pm_domain_data {
455 struct list_head list_node;
456 struct device *dev;
457 };
458
459 struct pm_subsys_data {
460 spinlock_t lock;
461 unsigned int refcount;
462 #ifdef CONFIG_PM_CLK
463 struct list_head clock_list;
464 #endif
465 #ifdef CONFIG_PM_GENERIC_DOMAINS
466 struct pm_domain_data *domain_data;
467 #endif
468 };
469
470 struct dev_pm_info {
471 pm_message_t power_state;
472 unsigned int can_wakeup:1;
473 unsigned int async_suspend:1;
474 bool is_prepared:1; /* Owned by the PM core */
475 bool is_suspended:1; /* Ditto */
476 bool ignore_children:1;
477 spinlock_t lock;
478 #ifdef CONFIG_PM_SLEEP
479 struct list_head entry;
480 struct completion completion;
481 struct wakeup_source *wakeup;
482 bool wakeup_path:1;
483 #else
484 unsigned int should_wakeup:1;
485 #endif
486 #ifdef CONFIG_PM_RUNTIME
487 struct timer_list suspend_timer;
488 unsigned long timer_expires;
489 struct work_struct work;
490 wait_queue_head_t wait_queue;
491 atomic_t usage_count;
492 atomic_t child_count;
493 unsigned int disable_depth:3;
494 unsigned int idle_notification:1;
495 unsigned int request_pending:1;
496 unsigned int deferred_resume:1;
497 unsigned int run_wake:1;
498 unsigned int runtime_auto:1;
499 unsigned int no_callbacks:1;
500 unsigned int irq_safe:1;
501 unsigned int use_autosuspend:1;
502 unsigned int timer_autosuspends:1;
503 enum rpm_request request;
504 enum rpm_status runtime_status;
505 int runtime_error;
506 int autosuspend_delay;
507 unsigned long last_busy;
508 unsigned long active_jiffies;
509 unsigned long suspended_jiffies;
510 unsigned long accounting_timestamp;
511 ktime_t suspend_time;
512 s64 max_time_suspended_ns;
513 #endif
514 struct pm_subsys_data *subsys_data; /* Owned by the subsystem. */
515 struct pm_qos_constraints *constraints;
516 };
517
518 extern void update_pm_runtime_accounting(struct device *dev);
519 extern int dev_pm_get_subsys_data(struct device *dev);
520 extern int dev_pm_put_subsys_data(struct device *dev);
521
522 /*
523 * Power domains provide callbacks that are executed during system suspend,
524 * hibernation, system resume and during runtime PM transitions along with
525 * subsystem-level and driver-level callbacks.
526 */
527 struct dev_pm_domain {
528 struct dev_pm_ops ops;
529 };
530
531 /*
532 * The PM_EVENT_ messages are also used by drivers implementing the legacy
533 * suspend framework, based on the ->suspend() and ->resume() callbacks common
534 * for suspend and hibernation transitions, according to the rules below.
535 */
536
537 /* Necessary, because several drivers use PM_EVENT_PRETHAW */
538 #define PM_EVENT_PRETHAW PM_EVENT_QUIESCE
539
540 /*
541 * One transition is triggered by resume(), after a suspend() call; the
542 * message is implicit:
543 *
544 * ON Driver starts working again, responding to hardware events
545 * and software requests. The hardware may have gone through
546 * a power-off reset, or it may have maintained state from the
547 * previous suspend() which the driver will rely on while
548 * resuming. On most platforms, there are no restrictions on
549 * availability of resources like clocks during resume().
550 *
551 * Other transitions are triggered by messages sent using suspend(). All
552 * these transitions quiesce the driver, so that I/O queues are inactive.
553 * That commonly entails turning off IRQs and DMA; there may be rules
554 * about how to quiesce that are specific to the bus or the device's type.
555 * (For example, network drivers mark the link state.) Other details may
556 * differ according to the message:
557 *
558 * SUSPEND Quiesce, enter a low power device state appropriate for
559 * the upcoming system state (such as PCI_D3hot), and enable
560 * wakeup events as appropriate.
561 *
562 * HIBERNATE Enter a low power device state appropriate for the hibernation
563 * state (eg. ACPI S4) and enable wakeup events as appropriate.
564 *
565 * FREEZE Quiesce operations so that a consistent image can be saved;
566 * but do NOT otherwise enter a low power device state, and do
567 * NOT emit system wakeup events.
568 *
569 * PRETHAW Quiesce as if for FREEZE; additionally, prepare for restoring
570 * the system from a snapshot taken after an earlier FREEZE.
571 * Some drivers will need to reset their hardware state instead
572 * of preserving it, to ensure that it's never mistaken for the
573 * state which that earlier snapshot had set up.
574 *
575 * A minimally power-aware driver treats all messages as SUSPEND, fully
576 * reinitializes its device during resume() -- whether or not it was reset
577 * during the suspend/resume cycle -- and can't issue wakeup events.
578 *
579 * More power-aware drivers may also use low power states at runtime as
580 * well as during system sleep states like PM_SUSPEND_STANDBY. They may
581 * be able to use wakeup events to exit from runtime low-power states,
582 * or from system low-power states such as standby or suspend-to-RAM.
583 */
584
585 #ifdef CONFIG_PM_SLEEP
586 extern void device_pm_lock(void);
587 extern void dpm_resume_noirq(pm_message_t state);
588 extern void dpm_resume_end(pm_message_t state);
589 extern void dpm_resume(pm_message_t state);
590 extern void dpm_complete(pm_message_t state);
591
592 extern void device_pm_unlock(void);
593 extern int dpm_suspend_noirq(pm_message_t state);
594 extern int dpm_suspend_start(pm_message_t state);
595 extern int dpm_suspend(pm_message_t state);
596 extern int dpm_prepare(pm_message_t state);
597
598 extern void __suspend_report_result(const char *function, void *fn, int ret);
599
600 #define suspend_report_result(fn, ret) \
601 do { \
602 __suspend_report_result(__func__, fn, ret); \
603 } while (0)
604
605 extern int device_pm_wait_for_dev(struct device *sub, struct device *dev);
606
607 extern int pm_generic_prepare(struct device *dev);
608 extern int pm_generic_suspend_noirq(struct device *dev);
609 extern int pm_generic_suspend(struct device *dev);
610 extern int pm_generic_resume_noirq(struct device *dev);
611 extern int pm_generic_resume(struct device *dev);
612 extern int pm_generic_freeze_noirq(struct device *dev);
613 extern int pm_generic_freeze(struct device *dev);
614 extern int pm_generic_thaw_noirq(struct device *dev);
615 extern int pm_generic_thaw(struct device *dev);
616 extern int pm_generic_restore_noirq(struct device *dev);
617 extern int pm_generic_restore(struct device *dev);
618 extern int pm_generic_poweroff_noirq(struct device *dev);
619 extern int pm_generic_poweroff(struct device *dev);
620 extern void pm_generic_complete(struct device *dev);
621
622 #else /* !CONFIG_PM_SLEEP */
623
624 #define device_pm_lock() do {} while (0)
625 #define device_pm_unlock() do {} while (0)
626
dpm_suspend_start(pm_message_t state)627 static inline int dpm_suspend_start(pm_message_t state)
628 {
629 return 0;
630 }
631
632 #define suspend_report_result(fn, ret) do {} while (0)
633
device_pm_wait_for_dev(struct device * a,struct device * b)634 static inline int device_pm_wait_for_dev(struct device *a, struct device *b)
635 {
636 return 0;
637 }
638
639 #define pm_generic_prepare NULL
640 #define pm_generic_suspend NULL
641 #define pm_generic_resume NULL
642 #define pm_generic_freeze NULL
643 #define pm_generic_thaw NULL
644 #define pm_generic_restore NULL
645 #define pm_generic_poweroff NULL
646 #define pm_generic_complete NULL
647 #endif /* !CONFIG_PM_SLEEP */
648
649 /* How to reorder dpm_list after device_move() */
650 enum dpm_order {
651 DPM_ORDER_NONE,
652 DPM_ORDER_DEV_AFTER_PARENT,
653 DPM_ORDER_PARENT_BEFORE_DEV,
654 DPM_ORDER_DEV_LAST,
655 };
656
657 #endif /* _LINUX_PM_H */
658