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
44 typedef struct pm_message
{
49 * struct dev_pm_ops - device PM callbacks
51 * Several driver power state transitions are externally visible, affecting
52 * the state of pending I/O queues and (for drivers that touch hardware)
53 * interrupts, wakeups, DMA, and other hardware state. There may also be
54 * internal transitions to various low power modes, which are transparent
55 * to the rest of the driver stack (such as a driver that's ON gating off
56 * clocks which are not in active use).
58 * The externally visible transitions are handled with the help of the following
59 * callbacks included in this structure:
61 * @prepare: Prepare the device for the upcoming transition, but do NOT change
62 * its hardware state. Prevent new children of the device from being
63 * registered after @prepare() returns (the driver's subsystem and
64 * generally the rest of the kernel is supposed to prevent new calls to the
65 * probe method from being made too once @prepare() has succeeded). If
66 * @prepare() detects a situation it cannot handle (e.g. registration of a
67 * child already in progress), it may return -EAGAIN, so that the PM core
68 * can execute it once again (e.g. after the new child has been registered)
69 * to recover from the race condition. This method is executed for all
70 * kinds of suspend transitions and is followed by one of the suspend
71 * callbacks: @suspend(), @freeze(), or @poweroff().
72 * The PM core executes @prepare() for all devices before starting to
73 * execute suspend callbacks for any of them, so drivers may assume all of
74 * the other devices to be present and functional while @prepare() is being
75 * executed. In particular, it is safe to make GFP_KERNEL memory
76 * allocations from within @prepare(). However, drivers may NOT assume
77 * anything about the availability of the user space at that time and it
78 * is not correct to request firmware from within @prepare() (it's too
79 * late to do that). [To work around this limitation, drivers may
80 * register suspend and hibernation notifiers that are executed before the
83 * @complete: Undo the changes made by @prepare(). This method is executed for
84 * all kinds of resume transitions, following one of the resume callbacks:
85 * @resume(), @thaw(), @restore(). Also called if the state transition
86 * fails before the driver's suspend callback (@suspend(), @freeze(),
87 * @poweroff()) can be executed (e.g. if the suspend callback fails for one
88 * of the other devices that the PM core has unsuccessfully attempted to
90 * The PM core executes @complete() after it has executed the appropriate
91 * resume callback for all devices.
93 * @suspend: Executed before putting the system into a sleep state in which the
94 * contents of main memory are preserved. Quiesce the device, put it into
95 * a low power state appropriate for the upcoming system state (such as
96 * PCI_D3hot), and enable wakeup events as appropriate.
98 * @resume: Executed after waking the system up from a sleep state in which the
99 * contents of main memory were preserved. Put the device into the
100 * appropriate state, according to the information saved in memory by the
101 * preceding @suspend(). The driver starts working again, responding to
102 * hardware events and software requests. The hardware may have gone
103 * through a power-off reset, or it may have maintained state from the
104 * previous suspend() which the driver may rely on while resuming. On most
105 * platforms, there are no restrictions on availability of resources like
106 * clocks during @resume().
108 * @freeze: Hibernation-specific, executed before creating a hibernation image.
109 * Quiesce operations so that a consistent image can be created, but do NOT
110 * otherwise put the device into a low power device state and do NOT emit
111 * system wakeup events. Save in main memory the device settings to be
112 * used by @restore() during the subsequent resume from hibernation or by
113 * the subsequent @thaw(), if the creation of the image or the restoration
114 * of main memory contents from it fails.
116 * @thaw: Hibernation-specific, executed after creating a hibernation image OR
117 * if the creation of the image fails. Also executed after a failing
118 * attempt to restore the contents of main memory from such an image.
119 * Undo the changes made by the preceding @freeze(), so the device can be
120 * operated in the same way as immediately before the call to @freeze().
122 * @poweroff: Hibernation-specific, executed after saving a hibernation image.
123 * Quiesce the device, put it into a low power state appropriate for the
124 * upcoming system state (such as PCI_D3hot), and enable wakeup events as
127 * @restore: Hibernation-specific, executed after restoring the contents of main
128 * memory from a hibernation image. Driver starts working again,
129 * responding to hardware events and software requests. Drivers may NOT
130 * make ANY assumptions about the hardware state right prior to @restore().
131 * On most platforms, there are no restrictions on availability of
132 * resources like clocks during @restore().
134 * @suspend_noirq: Complete the operations of ->suspend() by carrying out any
135 * actions required for suspending the device that need interrupts to be
138 * @resume_noirq: Prepare for the execution of ->resume() by carrying out any
139 * actions required for resuming the device that need interrupts to be
142 * @freeze_noirq: Complete the operations of ->freeze() by carrying out any
143 * actions required for freezing the device that need interrupts to be
146 * @thaw_noirq: Prepare for the execution of ->thaw() by carrying out any
147 * actions required for thawing the device that need interrupts to be
150 * @poweroff_noirq: Complete the operations of ->poweroff() by carrying out any
151 * actions required for handling the device that need interrupts to be
154 * @restore_noirq: Prepare for the execution of ->restore() by carrying out any
155 * actions required for restoring the operations of the device that need
156 * interrupts to be disabled
158 * All of the above callbacks, except for @complete(), return error codes.
159 * However, the error codes returned by the resume operations, @resume(),
160 * @thaw(), @restore(), @resume_noirq(), @thaw_noirq(), and @restore_noirq() do
161 * not cause the PM core to abort the resume transition during which they are
162 * returned. The error codes returned in that cases are only printed by the PM
163 * core to the system logs for debugging purposes. Still, it is recommended
164 * that drivers only return error codes from their resume methods in case of an
165 * unrecoverable failure (i.e. when the device being handled refuses to resume
166 * and becomes unusable) to allow us to modify the PM core in the future, so
167 * that it can avoid attempting to handle devices that failed to resume and
170 * It is allowed to unregister devices while the above callbacks are being
171 * executed. However, it is not allowed to unregister a device from within any
172 * of its own callbacks.
174 * There also are the following callbacks related to run-time power management
177 * @runtime_suspend: Prepare the device for a condition in which it won't be
178 * able to communicate with the CPU(s) and RAM due to power management.
179 * This need not mean that the device should be put into a low power state.
180 * For example, if the device is behind a link which is about to be turned
181 * off, the device may remain at full power. If the device does go to low
182 * power and is capable of generating run-time wake-up events, remote
183 * wake-up (i.e., a hardware mechanism allowing the device to request a
184 * change of its power state via a wake-up event, such as PCI PME) should
187 * @runtime_resume: Put the device into the fully active state in response to a
188 * wake-up event generated by hardware or at the request of software. If
189 * necessary, put the device into the full power state and restore its
190 * registers, so that it is fully operational.
192 * @runtime_idle: Device appears to be inactive and it might be put into a low
193 * power state if all of the necessary conditions are satisfied. Check
194 * these conditions and handle the device as appropriate, possibly queueing
195 * a suspend request for it. The return value is ignored by the PM core.
199 int (*prepare
)(struct device
*dev
);
200 void (*complete
)(struct device
*dev
);
201 int (*suspend
)(struct device
*dev
);
202 int (*resume
)(struct device
*dev
);
203 int (*freeze
)(struct device
*dev
);
204 int (*thaw
)(struct device
*dev
);
205 int (*poweroff
)(struct device
*dev
);
206 int (*restore
)(struct device
*dev
);
207 int (*suspend_noirq
)(struct device
*dev
);
208 int (*resume_noirq
)(struct device
*dev
);
209 int (*freeze_noirq
)(struct device
*dev
);
210 int (*thaw_noirq
)(struct device
*dev
);
211 int (*poweroff_noirq
)(struct device
*dev
);
212 int (*restore_noirq
)(struct device
*dev
);
213 int (*runtime_suspend
)(struct device
*dev
);
214 int (*runtime_resume
)(struct device
*dev
);
215 int (*runtime_idle
)(struct device
*dev
);
218 #ifdef CONFIG_PM_SLEEP
219 #define SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
220 .suspend = suspend_fn, \
221 .resume = resume_fn, \
222 .freeze = suspend_fn, \
224 .poweroff = suspend_fn, \
225 .restore = resume_fn,
227 #define SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn)
230 #ifdef CONFIG_PM_RUNTIME
231 #define SET_RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn) \
232 .runtime_suspend = suspend_fn, \
233 .runtime_resume = resume_fn, \
234 .runtime_idle = idle_fn,
236 #define SET_RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn)
240 * Use this if you want to use the same suspend and resume callbacks for suspend
241 * to RAM and hibernation.
243 #define SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn) \
244 const struct dev_pm_ops name = { \
245 SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
249 * Use this for defining a set of PM operations to be used in all situations
250 * (sustem suspend, hibernation or runtime PM).
252 #define UNIVERSAL_DEV_PM_OPS(name, suspend_fn, resume_fn, idle_fn) \
253 const struct dev_pm_ops name = { \
254 SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
255 SET_RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn) \
259 * Use this for subsystems (bus types, device types, device classes) that don't
260 * need any special suspend/resume handling in addition to invoking the PM
261 * callbacks provided by device drivers supporting both the system sleep PM and
262 * runtime PM, make the pm member point to generic_subsys_pm_ops.
265 extern struct dev_pm_ops generic_subsys_pm_ops
;
266 #define GENERIC_SUBSYS_PM_OPS (&generic_subsys_pm_ops)
268 #define GENERIC_SUBSYS_PM_OPS NULL
274 * The following PM_EVENT_ messages are defined for the internal use of the PM
275 * core, in order to provide a mechanism allowing the high level suspend and
276 * hibernation code to convey the necessary information to the device PM core
281 * FREEZE System is going to hibernate, call ->prepare() and ->freeze()
284 * SUSPEND System is going to suspend, call ->prepare() and ->suspend()
287 * HIBERNATE Hibernation image has been saved, call ->prepare() and
288 * ->poweroff() for all devices.
290 * QUIESCE Contents of main memory are going to be restored from a (loaded)
291 * hibernation image, call ->prepare() and ->freeze() for all
294 * RESUME System is resuming, call ->resume() and ->complete() for all
297 * THAW Hibernation image has been created, call ->thaw() and
298 * ->complete() for all devices.
300 * RESTORE Contents of main memory have been restored from a hibernation
301 * image, call ->restore() and ->complete() for all devices.
303 * RECOVER Creation of a hibernation image or restoration of the main
304 * memory contents from a hibernation image has failed, call
305 * ->thaw() and ->complete() for all devices.
307 * The following PM_EVENT_ messages are defined for internal use by
308 * kernel subsystems. They are never issued by the PM core.
310 * USER_SUSPEND Manual selective suspend was issued by userspace.
312 * USER_RESUME Manual selective resume was issued by userspace.
314 * REMOTE_WAKEUP Remote-wakeup request was received from the device.
316 * AUTO_SUSPEND Automatic (device idle) runtime suspend was
317 * initiated by the subsystem.
319 * AUTO_RESUME Automatic (device needed) runtime resume was
320 * requested by a driver.
323 #define PM_EVENT_ON 0x0000
324 #define PM_EVENT_FREEZE 0x0001
325 #define PM_EVENT_SUSPEND 0x0002
326 #define PM_EVENT_HIBERNATE 0x0004
327 #define PM_EVENT_QUIESCE 0x0008
328 #define PM_EVENT_RESUME 0x0010
329 #define PM_EVENT_THAW 0x0020
330 #define PM_EVENT_RESTORE 0x0040
331 #define PM_EVENT_RECOVER 0x0080
332 #define PM_EVENT_USER 0x0100
333 #define PM_EVENT_REMOTE 0x0200
334 #define PM_EVENT_AUTO 0x0400
336 #define PM_EVENT_SLEEP (PM_EVENT_SUSPEND | PM_EVENT_HIBERNATE)
337 #define PM_EVENT_USER_SUSPEND (PM_EVENT_USER | PM_EVENT_SUSPEND)
338 #define PM_EVENT_USER_RESUME (PM_EVENT_USER | PM_EVENT_RESUME)
339 #define PM_EVENT_REMOTE_RESUME (PM_EVENT_REMOTE | PM_EVENT_RESUME)
340 #define PM_EVENT_AUTO_SUSPEND (PM_EVENT_AUTO | PM_EVENT_SUSPEND)
341 #define PM_EVENT_AUTO_RESUME (PM_EVENT_AUTO | PM_EVENT_RESUME)
343 #define PMSG_ON ((struct pm_message){ .event = PM_EVENT_ON, })
344 #define PMSG_FREEZE ((struct pm_message){ .event = PM_EVENT_FREEZE, })
345 #define PMSG_QUIESCE ((struct pm_message){ .event = PM_EVENT_QUIESCE, })
346 #define PMSG_SUSPEND ((struct pm_message){ .event = PM_EVENT_SUSPEND, })
347 #define PMSG_HIBERNATE ((struct pm_message){ .event = PM_EVENT_HIBERNATE, })
348 #define PMSG_RESUME ((struct pm_message){ .event = PM_EVENT_RESUME, })
349 #define PMSG_THAW ((struct pm_message){ .event = PM_EVENT_THAW, })
350 #define PMSG_RESTORE ((struct pm_message){ .event = PM_EVENT_RESTORE, })
351 #define PMSG_RECOVER ((struct pm_message){ .event = PM_EVENT_RECOVER, })
352 #define PMSG_USER_SUSPEND ((struct pm_message) \
353 { .event = PM_EVENT_USER_SUSPEND, })
354 #define PMSG_USER_RESUME ((struct pm_message) \
355 { .event = PM_EVENT_USER_RESUME, })
356 #define PMSG_REMOTE_RESUME ((struct pm_message) \
357 { .event = PM_EVENT_REMOTE_RESUME, })
358 #define PMSG_AUTO_SUSPEND ((struct pm_message) \
359 { .event = PM_EVENT_AUTO_SUSPEND, })
360 #define PMSG_AUTO_RESUME ((struct pm_message) \
361 { .event = PM_EVENT_AUTO_RESUME, })
364 * Device power management states
366 * These state labels are used internally by the PM core to indicate the current
367 * status of a device with respect to the PM core operations.
369 * DPM_ON Device is regarded as operational. Set this way
370 * initially and when ->complete() is about to be called.
371 * Also set when ->prepare() fails.
373 * DPM_PREPARING Device is going to be prepared for a PM transition. Set
374 * when ->prepare() is about to be called.
376 * DPM_RESUMING Device is going to be resumed. Set when ->resume(),
377 * ->thaw(), or ->restore() is about to be called.
379 * DPM_SUSPENDING Device has been prepared for a power transition. Set
380 * when ->prepare() has just succeeded.
382 * DPM_OFF Device is regarded as inactive. Set immediately after
383 * ->suspend(), ->freeze(), or ->poweroff() has succeeded.
384 * Also set when ->resume()_noirq, ->thaw_noirq(), or
385 * ->restore_noirq() is about to be called.
387 * DPM_OFF_IRQ Device is in a "deep sleep". Set immediately after
388 * ->suspend_noirq(), ->freeze_noirq(), or
389 * ->poweroff_noirq() has just succeeded.
403 * Device run-time power management status.
405 * These status labels are used internally by the PM core to indicate the
406 * current status of a device with respect to the PM core operations. They do
407 * not reflect the actual power state of the device or its status as seen by the
410 * RPM_ACTIVE Device is fully operational. Indicates that the device
411 * bus type's ->runtime_resume() callback has completed
414 * RPM_SUSPENDED Device bus type's ->runtime_suspend() callback has
415 * completed successfully. The device is regarded as
418 * RPM_RESUMING Device bus type's ->runtime_resume() callback is being
421 * RPM_SUSPENDING Device bus type's ->runtime_suspend() callback is being
433 * Device run-time power management request types.
435 * RPM_REQ_NONE Do nothing.
437 * RPM_REQ_IDLE Run the device bus type's ->runtime_idle() callback
439 * RPM_REQ_SUSPEND Run the device bus type's ->runtime_suspend() callback
441 * RPM_REQ_RESUME Run the device bus type's ->runtime_resume() callback
451 struct wakeup_source
;
454 pm_message_t power_state
;
455 unsigned int can_wakeup
:1;
456 unsigned async_suspend
:1;
457 enum dpm_state status
; /* Owned by the PM core */
459 #ifdef CONFIG_PM_SLEEP
460 struct list_head entry
;
461 struct completion completion
;
462 struct wakeup_source
*wakeup
;
464 #ifdef CONFIG_PM_RUNTIME
465 struct timer_list suspend_timer
;
466 unsigned long timer_expires
;
467 struct work_struct work
;
468 wait_queue_head_t wait_queue
;
469 atomic_t usage_count
;
470 atomic_t child_count
;
471 unsigned int disable_depth
:3;
472 unsigned int ignore_children
:1;
473 unsigned int idle_notification
:1;
474 unsigned int request_pending
:1;
475 unsigned int deferred_resume
:1;
476 unsigned int run_wake
:1;
477 unsigned int runtime_auto
:1;
478 enum rpm_request request
;
479 enum rpm_status runtime_status
;
481 unsigned long active_jiffies
;
482 unsigned long suspended_jiffies
;
483 unsigned long accounting_timestamp
;
487 extern void update_pm_runtime_accounting(struct device
*dev
);
491 * The PM_EVENT_ messages are also used by drivers implementing the legacy
492 * suspend framework, based on the ->suspend() and ->resume() callbacks common
493 * for suspend and hibernation transitions, according to the rules below.
496 /* Necessary, because several drivers use PM_EVENT_PRETHAW */
497 #define PM_EVENT_PRETHAW PM_EVENT_QUIESCE
500 * One transition is triggered by resume(), after a suspend() call; the
501 * message is implicit:
503 * ON Driver starts working again, responding to hardware events
504 * and software requests. The hardware may have gone through
505 * a power-off reset, or it may have maintained state from the
506 * previous suspend() which the driver will rely on while
507 * resuming. On most platforms, there are no restrictions on
508 * availability of resources like clocks during resume().
510 * Other transitions are triggered by messages sent using suspend(). All
511 * these transitions quiesce the driver, so that I/O queues are inactive.
512 * That commonly entails turning off IRQs and DMA; there may be rules
513 * about how to quiesce that are specific to the bus or the device's type.
514 * (For example, network drivers mark the link state.) Other details may
515 * differ according to the message:
517 * SUSPEND Quiesce, enter a low power device state appropriate for
518 * the upcoming system state (such as PCI_D3hot), and enable
519 * wakeup events as appropriate.
521 * HIBERNATE Enter a low power device state appropriate for the hibernation
522 * state (eg. ACPI S4) and enable wakeup events as appropriate.
524 * FREEZE Quiesce operations so that a consistent image can be saved;
525 * but do NOT otherwise enter a low power device state, and do
526 * NOT emit system wakeup events.
528 * PRETHAW Quiesce as if for FREEZE; additionally, prepare for restoring
529 * the system from a snapshot taken after an earlier FREEZE.
530 * Some drivers will need to reset their hardware state instead
531 * of preserving it, to ensure that it's never mistaken for the
532 * state which that earlier snapshot had set up.
534 * A minimally power-aware driver treats all messages as SUSPEND, fully
535 * reinitializes its device during resume() -- whether or not it was reset
536 * during the suspend/resume cycle -- and can't issue wakeup events.
538 * More power-aware drivers may also use low power states at runtime as
539 * well as during system sleep states like PM_SUSPEND_STANDBY. They may
540 * be able to use wakeup events to exit from runtime low-power states,
541 * or from system low-power states such as standby or suspend-to-RAM.
544 #ifdef CONFIG_PM_SLEEP
545 extern void device_pm_lock(void);
546 extern int sysdev_resume(void);
547 extern void dpm_resume_noirq(pm_message_t state
);
548 extern void dpm_resume_end(pm_message_t state
);
550 extern void device_pm_unlock(void);
551 extern int sysdev_suspend(pm_message_t state
);
552 extern int dpm_suspend_noirq(pm_message_t state
);
553 extern int dpm_suspend_start(pm_message_t state
);
555 extern void __suspend_report_result(const char *function
, void *fn
, int ret
);
557 #define suspend_report_result(fn, ret) \
559 __suspend_report_result(__func__, fn, ret); \
562 extern int device_pm_wait_for_dev(struct device
*sub
, struct device
*dev
);
563 #else /* !CONFIG_PM_SLEEP */
565 #define device_pm_lock() do {} while (0)
566 #define device_pm_unlock() do {} while (0)
568 static inline int dpm_suspend_start(pm_message_t state
)
573 #define suspend_report_result(fn, ret) do {} while (0)
575 static inline int device_pm_wait_for_dev(struct device
*a
, struct device
*b
)
579 #endif /* !CONFIG_PM_SLEEP */
581 /* How to reorder dpm_list after device_move() */
584 DPM_ORDER_DEV_AFTER_PARENT
,
585 DPM_ORDER_PARENT_BEFORE_DEV
,
590 * Global Power Management flags
591 * Used to keep APM and ACPI from both being active
593 extern unsigned int pm_flags
;
598 #endif /* _LINUX_PM_H */