2 * pm.h - Power management interface
4 * Copyright (C) 2000 Andrew Henroid
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.
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.
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
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>
32 * Callbacks for platform drivers to implement.
34 extern void (*pm_idle
)(void);
35 extern void (*pm_power_off
)(void);
36 extern void (*pm_power_off_prepare
)(void);
39 * Device power management
45 extern const char power_group_name
[]; /* = "power" */
47 #define power_group_name NULL
50 typedef struct pm_message
{
55 * struct dev_pm_ops - device PM callbacks
57 * Several driver 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).
64 * The externally visible transitions are handled with the help of the following
65 * callbacks included in this structure:
67 * @prepare: Prepare the device for the upcoming transition, but do NOT change
68 * its hardware state. Prevent new children of the device from being
69 * registered after @prepare() returns (the driver's subsystem and
70 * generally the rest of the kernel is supposed to prevent new calls to the
71 * probe method from being made too once @prepare() has succeeded). If
72 * @prepare() detects a situation it cannot handle (e.g. registration of a
73 * child already in progress), it may return -EAGAIN, so that the PM core
74 * can execute it once again (e.g. after the new child has been registered)
75 * to recover from the race condition. This method is executed for all
76 * kinds of suspend transitions and is followed by one of the suspend
77 * callbacks: @suspend(), @freeze(), or @poweroff().
78 * The PM core executes @prepare() for all devices before starting to
79 * execute suspend callbacks for any of them, so drivers may assume all of
80 * the other devices to be present and functional while @prepare() is being
81 * executed. In particular, it is safe to make GFP_KERNEL memory
82 * allocations from within @prepare(). However, drivers may NOT assume
83 * anything about the availability of the user space at that time and it
84 * is not correct to request firmware from within @prepare() (it's too
85 * late to do that). [To work around this limitation, drivers may
86 * register suspend and hibernation notifiers that are executed before the
89 * @complete: Undo the changes made by @prepare(). This method is executed for
90 * all kinds of resume transitions, following one of the resume callbacks:
91 * @resume(), @thaw(), @restore(). Also called if the state transition
92 * fails before the driver's suspend callback (@suspend(), @freeze(),
93 * @poweroff()) can be executed (e.g. if the suspend callback fails for one
94 * of the other devices that the PM core has unsuccessfully attempted to
96 * The PM core executes @complete() after it has executed the appropriate
97 * resume callback for all devices.
99 * @suspend: Executed before putting the system into a sleep state in which the
100 * contents of main memory are preserved. Quiesce the device, put it into
101 * a low power state appropriate for the upcoming system state (such as
102 * PCI_D3hot), and enable wakeup events as appropriate.
104 * @resume: Executed after waking the system up from a sleep state in which the
105 * contents of main memory were preserved. Put the device into the
106 * appropriate state, according to the information saved in memory by the
107 * preceding @suspend(). The driver starts working again, responding to
108 * hardware events and software requests. The hardware may have gone
109 * through a power-off reset, or it may have maintained state from the
110 * previous suspend() which the driver may rely on while resuming. On most
111 * platforms, there are no restrictions on availability of resources like
112 * clocks during @resume().
114 * @freeze: Hibernation-specific, executed before creating a hibernation image.
115 * Quiesce operations so that a consistent image can be created, but do NOT
116 * otherwise put the device into a low power device state and do NOT emit
117 * system wakeup events. Save in main memory the device settings to be
118 * used by @restore() during the subsequent resume from hibernation or by
119 * the subsequent @thaw(), if the creation of the image or the restoration
120 * of main memory contents from it fails.
122 * @thaw: Hibernation-specific, executed after creating a hibernation image OR
123 * if the creation of the image fails. Also executed after a failing
124 * attempt to restore the contents of main memory from such an image.
125 * Undo the changes made by the preceding @freeze(), so the device can be
126 * operated in the same way as immediately before the call to @freeze().
128 * @poweroff: Hibernation-specific, executed after saving a hibernation image.
129 * Quiesce the device, put it into a low power state appropriate for the
130 * upcoming system state (such as PCI_D3hot), and enable wakeup events as
133 * @restore: Hibernation-specific, executed after restoring the contents of main
134 * memory from a hibernation image. Driver starts working again,
135 * responding to hardware events and software requests. Drivers may NOT
136 * make ANY assumptions about the hardware state right prior to @restore().
137 * On most platforms, there are no restrictions on availability of
138 * resources like clocks during @restore().
140 * @suspend_noirq: Complete the operations of ->suspend() by carrying out any
141 * actions required for suspending the device that need interrupts to be
144 * @resume_noirq: Prepare for the execution of ->resume() by carrying out any
145 * actions required for resuming the device that need interrupts to be
148 * @freeze_noirq: Complete the operations of ->freeze() by carrying out any
149 * actions required for freezing the device that need interrupts to be
152 * @thaw_noirq: Prepare for the execution of ->thaw() by carrying out any
153 * actions required for thawing the device that need interrupts to be
156 * @poweroff_noirq: Complete the operations of ->poweroff() by carrying out any
157 * actions required for handling the device that need interrupts to be
160 * @restore_noirq: Prepare for the execution of ->restore() by carrying out any
161 * actions required for restoring the operations of the device that need
162 * interrupts to be disabled
164 * All of the above callbacks, except for @complete(), return error codes.
165 * However, the error codes returned by the resume operations, @resume(),
166 * @thaw(), @restore(), @resume_noirq(), @thaw_noirq(), and @restore_noirq() do
167 * not cause the PM core to abort the resume transition during which they are
168 * returned. The error codes returned in that cases are only printed by the PM
169 * core to the system logs for debugging purposes. Still, it is recommended
170 * that drivers only return error codes from their resume methods in case of an
171 * unrecoverable failure (i.e. when the device being handled refuses to resume
172 * and becomes unusable) to allow us to modify the PM core in the future, so
173 * that it can avoid attempting to handle devices that failed to resume and
176 * It is allowed to unregister devices while the above callbacks are being
177 * executed. However, it is not allowed to unregister a device from within any
178 * of its own callbacks.
180 * There also are the following callbacks related to run-time power management
183 * @runtime_suspend: Prepare the device for a condition in which it won't be
184 * able to communicate with the CPU(s) and RAM due to power management.
185 * This need not mean that the device should be put into a low power state.
186 * For example, if the device is behind a link which is about to be turned
187 * off, the device may remain at full power. If the device does go to low
188 * power and is capable of generating run-time wake-up events, remote
189 * wake-up (i.e., a hardware mechanism allowing the device to request a
190 * change of its power state via a wake-up event, such as PCI PME) should
193 * @runtime_resume: Put the device into the fully active state in response to a
194 * wake-up event generated by hardware or at the request of software. If
195 * necessary, put the device into the full power state and restore its
196 * registers, so that it is fully operational.
198 * @runtime_idle: Device appears to be inactive and it might be put into a low
199 * power state if all of the necessary conditions are satisfied. Check
200 * these conditions and handle the device as appropriate, possibly queueing
201 * a suspend request for it. The return value is ignored by the PM core.
205 int (*prepare
)(struct device
*dev
);
206 void (*complete
)(struct device
*dev
);
207 int (*suspend
)(struct device
*dev
);
208 int (*resume
)(struct device
*dev
);
209 int (*freeze
)(struct device
*dev
);
210 int (*thaw
)(struct device
*dev
);
211 int (*poweroff
)(struct device
*dev
);
212 int (*restore
)(struct device
*dev
);
213 int (*suspend_noirq
)(struct device
*dev
);
214 int (*resume_noirq
)(struct device
*dev
);
215 int (*freeze_noirq
)(struct device
*dev
);
216 int (*thaw_noirq
)(struct device
*dev
);
217 int (*poweroff_noirq
)(struct device
*dev
);
218 int (*restore_noirq
)(struct device
*dev
);
219 int (*runtime_suspend
)(struct device
*dev
);
220 int (*runtime_resume
)(struct device
*dev
);
221 int (*runtime_idle
)(struct device
*dev
);
224 #ifdef CONFIG_PM_SLEEP
225 #define SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
226 .suspend = suspend_fn, \
227 .resume = resume_fn, \
228 .freeze = suspend_fn, \
230 .poweroff = suspend_fn, \
231 .restore = resume_fn,
233 #define SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn)
236 #ifdef CONFIG_PM_RUNTIME
237 #define SET_RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn) \
238 .runtime_suspend = suspend_fn, \
239 .runtime_resume = resume_fn, \
240 .runtime_idle = idle_fn,
242 #define SET_RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn)
246 * Use this if you want to use the same suspend and resume callbacks for suspend
247 * to RAM and hibernation.
249 #define SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn) \
250 const struct dev_pm_ops name = { \
251 SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
255 * Use this for defining a set of PM operations to be used in all situations
256 * (sustem suspend, hibernation or runtime PM).
258 #define UNIVERSAL_DEV_PM_OPS(name, suspend_fn, resume_fn, idle_fn) \
259 const struct dev_pm_ops name = { \
260 SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
261 SET_RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn) \
265 * Use this for subsystems (bus types, device types, device classes) that don't
266 * need any special suspend/resume handling in addition to invoking the PM
267 * callbacks provided by device drivers supporting both the system sleep PM and
268 * runtime PM, make the pm member point to generic_subsys_pm_ops.
271 extern struct dev_pm_ops generic_subsys_pm_ops
;
272 #define GENERIC_SUBSYS_PM_OPS (&generic_subsys_pm_ops)
274 #define GENERIC_SUBSYS_PM_OPS NULL
280 * The following PM_EVENT_ messages are defined for the internal use of the PM
281 * core, in order to provide a mechanism allowing the high level suspend and
282 * hibernation code to convey the necessary information to the device PM core
287 * FREEZE System is going to hibernate, call ->prepare() and ->freeze()
290 * SUSPEND System is going to suspend, call ->prepare() and ->suspend()
293 * HIBERNATE Hibernation image has been saved, call ->prepare() and
294 * ->poweroff() for all devices.
296 * QUIESCE Contents of main memory are going to be restored from a (loaded)
297 * hibernation image, call ->prepare() and ->freeze() for all
300 * RESUME System is resuming, call ->resume() and ->complete() for all
303 * THAW Hibernation image has been created, call ->thaw() and
304 * ->complete() for all devices.
306 * RESTORE Contents of main memory have been restored from a hibernation
307 * image, call ->restore() and ->complete() for all devices.
309 * RECOVER Creation of a hibernation image or restoration of the main
310 * memory contents from a hibernation image has failed, call
311 * ->thaw() and ->complete() for all devices.
313 * The following PM_EVENT_ messages are defined for internal use by
314 * kernel subsystems. They are never issued by the PM core.
316 * USER_SUSPEND Manual selective suspend was issued by userspace.
318 * USER_RESUME Manual selective resume was issued by userspace.
320 * REMOTE_WAKEUP Remote-wakeup request was received from the device.
322 * AUTO_SUSPEND Automatic (device idle) runtime suspend was
323 * initiated by the subsystem.
325 * AUTO_RESUME Automatic (device needed) runtime resume was
326 * requested by a driver.
329 #define PM_EVENT_ON 0x0000
330 #define PM_EVENT_FREEZE 0x0001
331 #define PM_EVENT_SUSPEND 0x0002
332 #define PM_EVENT_HIBERNATE 0x0004
333 #define PM_EVENT_QUIESCE 0x0008
334 #define PM_EVENT_RESUME 0x0010
335 #define PM_EVENT_THAW 0x0020
336 #define PM_EVENT_RESTORE 0x0040
337 #define PM_EVENT_RECOVER 0x0080
338 #define PM_EVENT_USER 0x0100
339 #define PM_EVENT_REMOTE 0x0200
340 #define PM_EVENT_AUTO 0x0400
342 #define PM_EVENT_SLEEP (PM_EVENT_SUSPEND | PM_EVENT_HIBERNATE)
343 #define PM_EVENT_USER_SUSPEND (PM_EVENT_USER | PM_EVENT_SUSPEND)
344 #define PM_EVENT_USER_RESUME (PM_EVENT_USER | PM_EVENT_RESUME)
345 #define PM_EVENT_REMOTE_RESUME (PM_EVENT_REMOTE | PM_EVENT_RESUME)
346 #define PM_EVENT_AUTO_SUSPEND (PM_EVENT_AUTO | PM_EVENT_SUSPEND)
347 #define PM_EVENT_AUTO_RESUME (PM_EVENT_AUTO | PM_EVENT_RESUME)
349 #define PMSG_ON ((struct pm_message){ .event = PM_EVENT_ON, })
350 #define PMSG_FREEZE ((struct pm_message){ .event = PM_EVENT_FREEZE, })
351 #define PMSG_QUIESCE ((struct pm_message){ .event = PM_EVENT_QUIESCE, })
352 #define PMSG_SUSPEND ((struct pm_message){ .event = PM_EVENT_SUSPEND, })
353 #define PMSG_HIBERNATE ((struct pm_message){ .event = PM_EVENT_HIBERNATE, })
354 #define PMSG_RESUME ((struct pm_message){ .event = PM_EVENT_RESUME, })
355 #define PMSG_THAW ((struct pm_message){ .event = PM_EVENT_THAW, })
356 #define PMSG_RESTORE ((struct pm_message){ .event = PM_EVENT_RESTORE, })
357 #define PMSG_RECOVER ((struct pm_message){ .event = PM_EVENT_RECOVER, })
358 #define PMSG_USER_SUSPEND ((struct pm_message) \
359 { .event = PM_EVENT_USER_SUSPEND, })
360 #define PMSG_USER_RESUME ((struct pm_message) \
361 { .event = PM_EVENT_USER_RESUME, })
362 #define PMSG_REMOTE_RESUME ((struct pm_message) \
363 { .event = PM_EVENT_REMOTE_RESUME, })
364 #define PMSG_AUTO_SUSPEND ((struct pm_message) \
365 { .event = PM_EVENT_AUTO_SUSPEND, })
366 #define PMSG_AUTO_RESUME ((struct pm_message) \
367 { .event = PM_EVENT_AUTO_RESUME, })
370 * Device run-time power management status.
372 * These status labels are used internally by the PM core to indicate the
373 * current status of a device with respect to the PM core operations. They do
374 * not reflect the actual power state of the device or its status as seen by the
377 * RPM_ACTIVE Device is fully operational. Indicates that the device
378 * bus type's ->runtime_resume() callback has completed
381 * RPM_SUSPENDED Device bus type's ->runtime_suspend() callback has
382 * completed successfully. The device is regarded as
385 * RPM_RESUMING Device bus type's ->runtime_resume() callback is being
388 * RPM_SUSPENDING Device bus type's ->runtime_suspend() callback is being
400 * Device run-time power management request types.
402 * RPM_REQ_NONE Do nothing.
404 * RPM_REQ_IDLE Run the device bus type's ->runtime_idle() callback
406 * RPM_REQ_SUSPEND Run the device bus type's ->runtime_suspend() callback
408 * RPM_REQ_AUTOSUSPEND Same as RPM_REQ_SUSPEND, but not until the device has
409 * been inactive for as long as power.autosuspend_delay
411 * RPM_REQ_RESUME Run the device bus type's ->runtime_resume() callback
422 struct wakeup_source
;
425 pm_message_t power_state
;
426 unsigned int can_wakeup
:1;
427 unsigned int async_suspend
:1;
428 bool is_prepared
:1; /* Owned by the PM core */
429 bool is_suspended
:1; /* Ditto */
431 #ifdef CONFIG_PM_SLEEP
432 struct list_head entry
;
433 struct completion completion
;
434 struct wakeup_source
*wakeup
;
436 unsigned int should_wakeup
:1;
438 #ifdef CONFIG_PM_RUNTIME
439 struct timer_list suspend_timer
;
440 unsigned long timer_expires
;
441 struct work_struct work
;
442 wait_queue_head_t wait_queue
;
443 atomic_t usage_count
;
444 atomic_t child_count
;
445 unsigned int disable_depth
:3;
446 unsigned int ignore_children
:1;
447 unsigned int idle_notification
:1;
448 unsigned int request_pending
:1;
449 unsigned int deferred_resume
:1;
450 unsigned int run_wake
:1;
451 unsigned int runtime_auto
:1;
452 unsigned int no_callbacks
:1;
453 unsigned int irq_safe
:1;
454 unsigned int use_autosuspend
:1;
455 unsigned int timer_autosuspends
:1;
456 enum rpm_request request
;
457 enum rpm_status runtime_status
;
459 int autosuspend_delay
;
460 unsigned long last_busy
;
461 unsigned long active_jiffies
;
462 unsigned long suspended_jiffies
;
463 unsigned long accounting_timestamp
;
464 void *subsys_data
; /* Owned by the subsystem. */
468 extern void update_pm_runtime_accounting(struct device
*dev
);
471 * Power domains provide callbacks that are executed during system suspend,
472 * hibernation, system resume and during runtime PM transitions along with
473 * subsystem-level and driver-level callbacks.
475 struct dev_power_domain
{
476 struct dev_pm_ops ops
;
480 * The PM_EVENT_ messages are also used by drivers implementing the legacy
481 * suspend framework, based on the ->suspend() and ->resume() callbacks common
482 * for suspend and hibernation transitions, according to the rules below.
485 /* Necessary, because several drivers use PM_EVENT_PRETHAW */
486 #define PM_EVENT_PRETHAW PM_EVENT_QUIESCE
489 * One transition is triggered by resume(), after a suspend() call; the
490 * message is implicit:
492 * ON Driver starts working again, responding to hardware events
493 * and software requests. The hardware may have gone through
494 * a power-off reset, or it may have maintained state from the
495 * previous suspend() which the driver will rely on while
496 * resuming. On most platforms, there are no restrictions on
497 * availability of resources like clocks during resume().
499 * Other transitions are triggered by messages sent using suspend(). All
500 * these transitions quiesce the driver, so that I/O queues are inactive.
501 * That commonly entails turning off IRQs and DMA; there may be rules
502 * about how to quiesce that are specific to the bus or the device's type.
503 * (For example, network drivers mark the link state.) Other details may
504 * differ according to the message:
506 * SUSPEND Quiesce, enter a low power device state appropriate for
507 * the upcoming system state (such as PCI_D3hot), and enable
508 * wakeup events as appropriate.
510 * HIBERNATE Enter a low power device state appropriate for the hibernation
511 * state (eg. ACPI S4) and enable wakeup events as appropriate.
513 * FREEZE Quiesce operations so that a consistent image can be saved;
514 * but do NOT otherwise enter a low power device state, and do
515 * NOT emit system wakeup events.
517 * PRETHAW Quiesce as if for FREEZE; additionally, prepare for restoring
518 * the system from a snapshot taken after an earlier FREEZE.
519 * Some drivers will need to reset their hardware state instead
520 * of preserving it, to ensure that it's never mistaken for the
521 * state which that earlier snapshot had set up.
523 * A minimally power-aware driver treats all messages as SUSPEND, fully
524 * reinitializes its device during resume() -- whether or not it was reset
525 * during the suspend/resume cycle -- and can't issue wakeup events.
527 * More power-aware drivers may also use low power states at runtime as
528 * well as during system sleep states like PM_SUSPEND_STANDBY. They may
529 * be able to use wakeup events to exit from runtime low-power states,
530 * or from system low-power states such as standby or suspend-to-RAM.
533 #ifdef CONFIG_PM_SLEEP
534 extern void device_pm_lock(void);
535 extern void dpm_resume_noirq(pm_message_t state
);
536 extern void dpm_resume_end(pm_message_t state
);
537 extern void dpm_resume(pm_message_t state
);
538 extern void dpm_complete(pm_message_t state
);
540 extern void device_pm_unlock(void);
541 extern int dpm_suspend_noirq(pm_message_t state
);
542 extern int dpm_suspend_start(pm_message_t state
);
543 extern int dpm_suspend(pm_message_t state
);
544 extern int dpm_prepare(pm_message_t state
);
546 extern void __suspend_report_result(const char *function
, void *fn
, int ret
);
548 #define suspend_report_result(fn, ret) \
550 __suspend_report_result(__func__, fn, ret); \
553 extern int device_pm_wait_for_dev(struct device
*sub
, struct device
*dev
);
555 extern int pm_generic_prepare(struct device
*dev
);
556 extern int pm_generic_suspend(struct device
*dev
);
557 extern int pm_generic_resume(struct device
*dev
);
558 extern int pm_generic_freeze(struct device
*dev
);
559 extern int pm_generic_thaw(struct device
*dev
);
560 extern int pm_generic_restore(struct device
*dev
);
561 extern int pm_generic_poweroff(struct device
*dev
);
562 extern void pm_generic_complete(struct device
*dev
);
564 #else /* !CONFIG_PM_SLEEP */
566 #define device_pm_lock() do {} while (0)
567 #define device_pm_unlock() do {} while (0)
569 static inline int dpm_suspend_start(pm_message_t state
)
574 #define suspend_report_result(fn, ret) do {} while (0)
576 static inline int device_pm_wait_for_dev(struct device
*a
, struct device
*b
)
581 #define pm_generic_prepare NULL
582 #define pm_generic_suspend NULL
583 #define pm_generic_resume NULL
584 #define pm_generic_freeze NULL
585 #define pm_generic_thaw NULL
586 #define pm_generic_restore NULL
587 #define pm_generic_poweroff NULL
588 #define pm_generic_complete NULL
589 #endif /* !CONFIG_PM_SLEEP */
591 /* How to reorder dpm_list after device_move() */
594 DPM_ORDER_DEV_AFTER_PARENT
,
595 DPM_ORDER_PARENT_BEFORE_DEV
,
599 #endif /* _LINUX_PM_H */