xref: /openbmc/linux/include/linux/pm.h (revision 94c7b6fc)
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_power_off)(void);
35 extern void (*pm_power_off_prepare)(void);
36 
37 struct device; /* we have a circular dep with device.h */
38 #ifdef CONFIG_VT_CONSOLE_SLEEP
39 extern void pm_vt_switch_required(struct device *dev, bool required);
40 extern void pm_vt_switch_unregister(struct device *dev);
41 #else
42 static inline void pm_vt_switch_required(struct device *dev, bool required)
43 {
44 }
45 static inline void pm_vt_switch_unregister(struct device *dev)
46 {
47 }
48 #endif /* CONFIG_VT_CONSOLE_SLEEP */
49 
50 /*
51  * Device power management
52  */
53 
54 struct device;
55 
56 #ifdef CONFIG_PM
57 extern const char power_group_name[];		/* = "power" */
58 #else
59 #define power_group_name	NULL
60 #endif
61 
62 typedef struct pm_message {
63 	int event;
64 } pm_message_t;
65 
66 /**
67  * struct dev_pm_ops - device PM callbacks
68  *
69  * Several device power state transitions are externally visible, affecting
70  * the state of pending I/O queues and (for drivers that touch hardware)
71  * interrupts, wakeups, DMA, and other hardware state.  There may also be
72  * internal transitions to various low-power modes which are transparent
73  * to the rest of the driver stack (such as a driver that's ON gating off
74  * clocks which are not in active use).
75  *
76  * The externally visible transitions are handled with the help of callbacks
77  * included in this structure in such a way that two levels of callbacks are
78  * involved.  First, the PM core executes callbacks provided by PM domains,
79  * device types, classes and bus types.  They are the subsystem-level callbacks
80  * supposed to execute callbacks provided by device drivers, although they may
81  * choose not to do that.  If the driver callbacks are executed, they have to
82  * collaborate with the subsystem-level callbacks to achieve the goals
83  * appropriate for the given system transition, given transition phase and the
84  * subsystem the device belongs to.
85  *
86  * @prepare: The principal role of this callback is to prevent new children of
87  *	the device from being registered after it has returned (the driver's
88  *	subsystem and generally the rest of the kernel is supposed to prevent
89  *	new calls to the probe method from being made too once @prepare() has
90  *	succeeded).  If @prepare() detects a situation it cannot handle (e.g.
91  *	registration of a child already in progress), it may return -EAGAIN, so
92  *	that the PM core can execute it once again (e.g. after a new child has
93  *	been registered) to recover from the race condition.
94  *	This method is executed for all kinds of suspend transitions and is
95  *	followed by one of the suspend callbacks: @suspend(), @freeze(), or
96  *	@poweroff().  If the transition is a suspend to memory or standby (that
97  *	is, not related to hibernation), the return value of @prepare() may be
98  *	used to indicate to the PM core to leave the device in runtime suspend
99  *	if applicable.  Namely, if @prepare() returns a positive number, the PM
100  *	core will understand that as a declaration that the device appears to be
101  *	runtime-suspended and it may be left in that state during the entire
102  *	transition and during the subsequent resume if all of its descendants
103  *	are left in runtime suspend too.  If that happens, @complete() will be
104  *	executed directly after @prepare() and it must ensure the proper
105  *	functioning of the device after the system resume.
106  *	The PM core executes subsystem-level @prepare() for all devices before
107  *	starting to invoke suspend callbacks for any of them, so generally
108  *	devices may be assumed to be functional or to respond to runtime resume
109  *	requests while @prepare() is being executed.  However, device drivers
110  *	may NOT assume anything about the availability of user space at that
111  *	time and it is NOT valid to request firmware from within @prepare()
112  *	(it's too late to do that).  It also is NOT valid to allocate
113  *	substantial amounts of memory from @prepare() in the GFP_KERNEL mode.
114  *	[To work around these limitations, drivers may register suspend and
115  *	hibernation notifiers to be executed before the freezing of tasks.]
116  *
117  * @complete: Undo the changes made by @prepare().  This method is executed for
118  *	all kinds of resume transitions, following one of the resume callbacks:
119  *	@resume(), @thaw(), @restore().  Also called if the state transition
120  *	fails before the driver's suspend callback: @suspend(), @freeze() or
121  *	@poweroff(), can be executed (e.g. if the suspend callback fails for one
122  *	of the other devices that the PM core has unsuccessfully attempted to
123  *	suspend earlier).
124  *	The PM core executes subsystem-level @complete() after it has executed
125  *	the appropriate resume callbacks for all devices.  If the corresponding
126  *	@prepare() at the beginning of the suspend transition returned a
127  *	positive number and the device was left in runtime suspend (without
128  *	executing any suspend and resume callbacks for it), @complete() will be
129  *	the only callback executed for the device during resume.  In that case,
130  *	@complete() must be prepared to do whatever is necessary to ensure the
131  *	proper functioning of the device after the system resume.  To this end,
132  *	@complete() can check the power.direct_complete flag of the device to
133  *	learn whether (unset) or not (set) the previous suspend and resume
134  *	callbacks have been executed for it.
135  *
136  * @suspend: Executed before putting the system into a sleep state in which the
137  *	contents of main memory are preserved.  The exact action to perform
138  *	depends on the device's subsystem (PM domain, device type, class or bus
139  *	type), but generally the device must be quiescent after subsystem-level
140  *	@suspend() has returned, so that it doesn't do any I/O or DMA.
141  *	Subsystem-level @suspend() is executed for all devices after invoking
142  *	subsystem-level @prepare() for all of them.
143  *
144  * @suspend_late: Continue operations started by @suspend().  For a number of
145  *	devices @suspend_late() may point to the same callback routine as the
146  *	runtime suspend callback.
147  *
148  * @resume: Executed after waking the system up from a sleep state in which the
149  *	contents of main memory were preserved.  The exact action to perform
150  *	depends on the device's subsystem, but generally the driver is expected
151  *	to start working again, responding to hardware events and software
152  *	requests (the device itself may be left in a low-power state, waiting
153  *	for a runtime resume to occur).  The state of the device at the time its
154  *	driver's @resume() callback is run depends on the platform and subsystem
155  *	the device belongs to.  On most platforms, there are no restrictions on
156  *	availability of resources like clocks during @resume().
157  *	Subsystem-level @resume() is executed for all devices after invoking
158  *	subsystem-level @resume_noirq() for all of them.
159  *
160  * @resume_early: Prepare to execute @resume().  For a number of devices
161  *	@resume_early() may point to the same callback routine as the runtime
162  *	resume callback.
163  *
164  * @freeze: Hibernation-specific, executed before creating a hibernation image.
165  *	Analogous to @suspend(), but it should not enable the device to signal
166  *	wakeup events or change its power state.  The majority of subsystems
167  *	(with the notable exception of the PCI bus type) expect the driver-level
168  *	@freeze() to save the device settings in memory to be used by @restore()
169  *	during the subsequent resume from hibernation.
170  *	Subsystem-level @freeze() is executed for all devices after invoking
171  *	subsystem-level @prepare() for all of them.
172  *
173  * @freeze_late: Continue operations started by @freeze().  Analogous to
174  *	@suspend_late(), but it should not enable the device to signal wakeup
175  *	events or change its power state.
176  *
177  * @thaw: Hibernation-specific, executed after creating a hibernation image OR
178  *	if the creation of an image has failed.  Also executed after a failing
179  *	attempt to restore the contents of main memory from such an image.
180  *	Undo the changes made by the preceding @freeze(), so the device can be
181  *	operated in the same way as immediately before the call to @freeze().
182  *	Subsystem-level @thaw() is executed for all devices after invoking
183  *	subsystem-level @thaw_noirq() for all of them.  It also may be executed
184  *	directly after @freeze() in case of a transition error.
185  *
186  * @thaw_early: Prepare to execute @thaw().  Undo the changes made by the
187  *	preceding @freeze_late().
188  *
189  * @poweroff: Hibernation-specific, executed after saving a hibernation image.
190  *	Analogous to @suspend(), but it need not save the device's settings in
191  *	memory.
192  *	Subsystem-level @poweroff() is executed for all devices after invoking
193  *	subsystem-level @prepare() for all of them.
194  *
195  * @poweroff_late: Continue operations started by @poweroff().  Analogous to
196  *	@suspend_late(), but it need not save the device's settings in memory.
197  *
198  * @restore: Hibernation-specific, executed after restoring the contents of main
199  *	memory from a hibernation image, analogous to @resume().
200  *
201  * @restore_early: Prepare to execute @restore(), analogous to @resume_early().
202  *
203  * @suspend_noirq: Complete the actions started by @suspend().  Carry out any
204  *	additional operations required for suspending the device that might be
205  *	racing with its driver's interrupt handler, which is guaranteed not to
206  *	run while @suspend_noirq() is being executed.
207  *	It generally is expected that the device will be in a low-power state
208  *	(appropriate for the target system sleep state) after subsystem-level
209  *	@suspend_noirq() has returned successfully.  If the device can generate
210  *	system wakeup signals and is enabled to wake up the system, it should be
211  *	configured to do so at that time.  However, depending on the platform
212  *	and device's subsystem, @suspend() or @suspend_late() may be allowed to
213  *	put the device into the low-power state and configure it to generate
214  *	wakeup signals, in which case it generally is not necessary to define
215  *	@suspend_noirq().
216  *
217  * @resume_noirq: Prepare for the execution of @resume() by carrying out any
218  *	operations required for resuming the device that might be racing with
219  *	its driver's interrupt handler, which is guaranteed not to run while
220  *	@resume_noirq() is being executed.
221  *
222  * @freeze_noirq: Complete the actions started by @freeze().  Carry out any
223  *	additional operations required for freezing the device that might be
224  *	racing with its driver's interrupt handler, which is guaranteed not to
225  *	run while @freeze_noirq() is being executed.
226  *	The power state of the device should not be changed by either @freeze(),
227  *	or @freeze_late(), or @freeze_noirq() and it should not be configured to
228  *	signal system wakeup by any of these callbacks.
229  *
230  * @thaw_noirq: Prepare for the execution of @thaw() by carrying out any
231  *	operations required for thawing the device that might be racing with its
232  *	driver's interrupt handler, which is guaranteed not to run while
233  *	@thaw_noirq() is being executed.
234  *
235  * @poweroff_noirq: Complete the actions started by @poweroff().  Analogous to
236  *	@suspend_noirq(), but it need not save the device's settings in memory.
237  *
238  * @restore_noirq: Prepare for the execution of @restore() by carrying out any
239  *	operations required for thawing the device that might be racing with its
240  *	driver's interrupt handler, which is guaranteed not to run while
241  *	@restore_noirq() is being executed.  Analogous to @resume_noirq().
242  *
243  * All of the above callbacks, except for @complete(), return error codes.
244  * However, the error codes returned by the resume operations, @resume(),
245  * @thaw(), @restore(), @resume_noirq(), @thaw_noirq(), and @restore_noirq(), do
246  * not cause the PM core to abort the resume transition during which they are
247  * returned.  The error codes returned in those cases are only printed by the PM
248  * core to the system logs for debugging purposes.  Still, it is recommended
249  * that drivers only return error codes from their resume methods in case of an
250  * unrecoverable failure (i.e. when the device being handled refuses to resume
251  * and becomes unusable) to allow us to modify the PM core in the future, so
252  * that it can avoid attempting to handle devices that failed to resume and
253  * their children.
254  *
255  * It is allowed to unregister devices while the above callbacks are being
256  * executed.  However, a callback routine must NOT try to unregister the device
257  * it was called for, although it may unregister children of that device (for
258  * example, if it detects that a child was unplugged while the system was
259  * asleep).
260  *
261  * Refer to Documentation/power/devices.txt for more information about the role
262  * of the above callbacks in the system suspend process.
263  *
264  * There also are callbacks related to runtime power management of devices.
265  * Again, these callbacks are executed by the PM core only for subsystems
266  * (PM domains, device types, classes and bus types) and the subsystem-level
267  * callbacks are supposed to invoke the driver callbacks.  Moreover, the exact
268  * actions to be performed by a device driver's callbacks generally depend on
269  * the platform and subsystem the device belongs to.
270  *
271  * @runtime_suspend: Prepare the device for a condition in which it won't be
272  *	able to communicate with the CPU(s) and RAM due to power management.
273  *	This need not mean that the device should be put into a low-power state.
274  *	For example, if the device is behind a link which is about to be turned
275  *	off, the device may remain at full power.  If the device does go to low
276  *	power and is capable of generating runtime wakeup events, remote wakeup
277  *	(i.e., a hardware mechanism allowing the device to request a change of
278  *	its power state via an interrupt) should be enabled for it.
279  *
280  * @runtime_resume: Put the device into the fully active state in response to a
281  *	wakeup event generated by hardware or at the request of software.  If
282  *	necessary, put the device into the full-power state and restore its
283  *	registers, so that it is fully operational.
284  *
285  * @runtime_idle: Device appears to be inactive and it might be put into a
286  *	low-power state if all of the necessary conditions are satisfied.
287  *	Check these conditions, and return 0 if it's appropriate to let the PM
288  *	core queue a suspend request for the device.
289  *
290  * Refer to Documentation/power/runtime_pm.txt for more information about the
291  * role of the above callbacks in device runtime power management.
292  *
293  */
294 
295 struct dev_pm_ops {
296 	int (*prepare)(struct device *dev);
297 	void (*complete)(struct device *dev);
298 	int (*suspend)(struct device *dev);
299 	int (*resume)(struct device *dev);
300 	int (*freeze)(struct device *dev);
301 	int (*thaw)(struct device *dev);
302 	int (*poweroff)(struct device *dev);
303 	int (*restore)(struct device *dev);
304 	int (*suspend_late)(struct device *dev);
305 	int (*resume_early)(struct device *dev);
306 	int (*freeze_late)(struct device *dev);
307 	int (*thaw_early)(struct device *dev);
308 	int (*poweroff_late)(struct device *dev);
309 	int (*restore_early)(struct device *dev);
310 	int (*suspend_noirq)(struct device *dev);
311 	int (*resume_noirq)(struct device *dev);
312 	int (*freeze_noirq)(struct device *dev);
313 	int (*thaw_noirq)(struct device *dev);
314 	int (*poweroff_noirq)(struct device *dev);
315 	int (*restore_noirq)(struct device *dev);
316 	int (*runtime_suspend)(struct device *dev);
317 	int (*runtime_resume)(struct device *dev);
318 	int (*runtime_idle)(struct device *dev);
319 };
320 
321 #ifdef CONFIG_PM_SLEEP
322 #define SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
323 	.suspend = suspend_fn, \
324 	.resume = resume_fn, \
325 	.freeze = suspend_fn, \
326 	.thaw = resume_fn, \
327 	.poweroff = suspend_fn, \
328 	.restore = resume_fn,
329 #else
330 #define SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn)
331 #endif
332 
333 #ifdef CONFIG_PM_SLEEP
334 #define SET_LATE_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
335 	.suspend_late = suspend_fn, \
336 	.resume_early = resume_fn, \
337 	.freeze_late = suspend_fn, \
338 	.thaw_early = resume_fn, \
339 	.poweroff_late = suspend_fn, \
340 	.restore_early = resume_fn,
341 #else
342 #define SET_LATE_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn)
343 #endif
344 
345 #ifdef CONFIG_PM_RUNTIME
346 #define SET_RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn) \
347 	.runtime_suspend = suspend_fn, \
348 	.runtime_resume = resume_fn, \
349 	.runtime_idle = idle_fn,
350 #else
351 #define SET_RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn)
352 #endif
353 
354 #ifdef CONFIG_PM
355 #define SET_PM_RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn) \
356 	.runtime_suspend = suspend_fn, \
357 	.runtime_resume = resume_fn, \
358 	.runtime_idle = idle_fn,
359 #else
360 #define SET_PM_RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn)
361 #endif
362 
363 /*
364  * Use this if you want to use the same suspend and resume callbacks for suspend
365  * to RAM and hibernation.
366  */
367 #define SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn) \
368 const struct dev_pm_ops name = { \
369 	SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
370 }
371 
372 /*
373  * Use this for defining a set of PM operations to be used in all situations
374  * (system suspend, hibernation or runtime PM).
375  * NOTE: In general, system suspend callbacks, .suspend() and .resume(), should
376  * be different from the corresponding runtime PM callbacks, .runtime_suspend(),
377  * and .runtime_resume(), because .runtime_suspend() always works on an already
378  * quiescent device, while .suspend() should assume that the device may be doing
379  * something when it is called (it should ensure that the device will be
380  * quiescent after it has returned).  Therefore it's better to point the "late"
381  * suspend and "early" resume callback pointers, .suspend_late() and
382  * .resume_early(), to the same routines as .runtime_suspend() and
383  * .runtime_resume(), respectively (and analogously for hibernation).
384  */
385 #define UNIVERSAL_DEV_PM_OPS(name, suspend_fn, resume_fn, idle_fn) \
386 const struct dev_pm_ops name = { \
387 	SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
388 	SET_RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn) \
389 }
390 
391 /**
392  * PM_EVENT_ messages
393  *
394  * The following PM_EVENT_ messages are defined for the internal use of the PM
395  * core, in order to provide a mechanism allowing the high level suspend and
396  * hibernation code to convey the necessary information to the device PM core
397  * code:
398  *
399  * ON		No transition.
400  *
401  * FREEZE	System is going to hibernate, call ->prepare() and ->freeze()
402  *		for all devices.
403  *
404  * SUSPEND	System is going to suspend, call ->prepare() and ->suspend()
405  *		for all devices.
406  *
407  * HIBERNATE	Hibernation image has been saved, call ->prepare() and
408  *		->poweroff() for all devices.
409  *
410  * QUIESCE	Contents of main memory are going to be restored from a (loaded)
411  *		hibernation image, call ->prepare() and ->freeze() for all
412  *		devices.
413  *
414  * RESUME	System is resuming, call ->resume() and ->complete() for all
415  *		devices.
416  *
417  * THAW		Hibernation image has been created, call ->thaw() and
418  *		->complete() for all devices.
419  *
420  * RESTORE	Contents of main memory have been restored from a hibernation
421  *		image, call ->restore() and ->complete() for all devices.
422  *
423  * RECOVER	Creation of a hibernation image or restoration of the main
424  *		memory contents from a hibernation image has failed, call
425  *		->thaw() and ->complete() for all devices.
426  *
427  * The following PM_EVENT_ messages are defined for internal use by
428  * kernel subsystems.  They are never issued by the PM core.
429  *
430  * USER_SUSPEND		Manual selective suspend was issued by userspace.
431  *
432  * USER_RESUME		Manual selective resume was issued by userspace.
433  *
434  * REMOTE_WAKEUP	Remote-wakeup request was received from the device.
435  *
436  * AUTO_SUSPEND		Automatic (device idle) runtime suspend was
437  *			initiated by the subsystem.
438  *
439  * AUTO_RESUME		Automatic (device needed) runtime resume was
440  *			requested by a driver.
441  */
442 
443 #define PM_EVENT_INVALID	(-1)
444 #define PM_EVENT_ON		0x0000
445 #define PM_EVENT_FREEZE		0x0001
446 #define PM_EVENT_SUSPEND	0x0002
447 #define PM_EVENT_HIBERNATE	0x0004
448 #define PM_EVENT_QUIESCE	0x0008
449 #define PM_EVENT_RESUME		0x0010
450 #define PM_EVENT_THAW		0x0020
451 #define PM_EVENT_RESTORE	0x0040
452 #define PM_EVENT_RECOVER	0x0080
453 #define PM_EVENT_USER		0x0100
454 #define PM_EVENT_REMOTE		0x0200
455 #define PM_EVENT_AUTO		0x0400
456 
457 #define PM_EVENT_SLEEP		(PM_EVENT_SUSPEND | PM_EVENT_HIBERNATE)
458 #define PM_EVENT_USER_SUSPEND	(PM_EVENT_USER | PM_EVENT_SUSPEND)
459 #define PM_EVENT_USER_RESUME	(PM_EVENT_USER | PM_EVENT_RESUME)
460 #define PM_EVENT_REMOTE_RESUME	(PM_EVENT_REMOTE | PM_EVENT_RESUME)
461 #define PM_EVENT_AUTO_SUSPEND	(PM_EVENT_AUTO | PM_EVENT_SUSPEND)
462 #define PM_EVENT_AUTO_RESUME	(PM_EVENT_AUTO | PM_EVENT_RESUME)
463 
464 #define PMSG_INVALID	((struct pm_message){ .event = PM_EVENT_INVALID, })
465 #define PMSG_ON		((struct pm_message){ .event = PM_EVENT_ON, })
466 #define PMSG_FREEZE	((struct pm_message){ .event = PM_EVENT_FREEZE, })
467 #define PMSG_QUIESCE	((struct pm_message){ .event = PM_EVENT_QUIESCE, })
468 #define PMSG_SUSPEND	((struct pm_message){ .event = PM_EVENT_SUSPEND, })
469 #define PMSG_HIBERNATE	((struct pm_message){ .event = PM_EVENT_HIBERNATE, })
470 #define PMSG_RESUME	((struct pm_message){ .event = PM_EVENT_RESUME, })
471 #define PMSG_THAW	((struct pm_message){ .event = PM_EVENT_THAW, })
472 #define PMSG_RESTORE	((struct pm_message){ .event = PM_EVENT_RESTORE, })
473 #define PMSG_RECOVER	((struct pm_message){ .event = PM_EVENT_RECOVER, })
474 #define PMSG_USER_SUSPEND	((struct pm_message) \
475 					{ .event = PM_EVENT_USER_SUSPEND, })
476 #define PMSG_USER_RESUME	((struct pm_message) \
477 					{ .event = PM_EVENT_USER_RESUME, })
478 #define PMSG_REMOTE_RESUME	((struct pm_message) \
479 					{ .event = PM_EVENT_REMOTE_RESUME, })
480 #define PMSG_AUTO_SUSPEND	((struct pm_message) \
481 					{ .event = PM_EVENT_AUTO_SUSPEND, })
482 #define PMSG_AUTO_RESUME	((struct pm_message) \
483 					{ .event = PM_EVENT_AUTO_RESUME, })
484 
485 #define PMSG_IS_AUTO(msg)	(((msg).event & PM_EVENT_AUTO) != 0)
486 
487 /**
488  * Device run-time power management status.
489  *
490  * These status labels are used internally by the PM core to indicate the
491  * current status of a device with respect to the PM core operations.  They do
492  * not reflect the actual power state of the device or its status as seen by the
493  * driver.
494  *
495  * RPM_ACTIVE		Device is fully operational.  Indicates that the device
496  *			bus type's ->runtime_resume() callback has completed
497  *			successfully.
498  *
499  * RPM_SUSPENDED	Device bus type's ->runtime_suspend() callback has
500  *			completed successfully.  The device is regarded as
501  *			suspended.
502  *
503  * RPM_RESUMING		Device bus type's ->runtime_resume() callback is being
504  *			executed.
505  *
506  * RPM_SUSPENDING	Device bus type's ->runtime_suspend() callback is being
507  *			executed.
508  */
509 
510 enum rpm_status {
511 	RPM_ACTIVE = 0,
512 	RPM_RESUMING,
513 	RPM_SUSPENDED,
514 	RPM_SUSPENDING,
515 };
516 
517 /**
518  * Device run-time power management request types.
519  *
520  * RPM_REQ_NONE		Do nothing.
521  *
522  * RPM_REQ_IDLE		Run the device bus type's ->runtime_idle() callback
523  *
524  * RPM_REQ_SUSPEND	Run the device bus type's ->runtime_suspend() callback
525  *
526  * RPM_REQ_AUTOSUSPEND	Same as RPM_REQ_SUSPEND, but not until the device has
527  *			been inactive for as long as power.autosuspend_delay
528  *
529  * RPM_REQ_RESUME	Run the device bus type's ->runtime_resume() callback
530  */
531 
532 enum rpm_request {
533 	RPM_REQ_NONE = 0,
534 	RPM_REQ_IDLE,
535 	RPM_REQ_SUSPEND,
536 	RPM_REQ_AUTOSUSPEND,
537 	RPM_REQ_RESUME,
538 };
539 
540 struct wakeup_source;
541 
542 struct pm_domain_data {
543 	struct list_head list_node;
544 	struct device *dev;
545 };
546 
547 struct pm_subsys_data {
548 	spinlock_t lock;
549 	unsigned int refcount;
550 #ifdef CONFIG_PM_CLK
551 	struct list_head clock_list;
552 #endif
553 #ifdef CONFIG_PM_GENERIC_DOMAINS
554 	struct pm_domain_data *domain_data;
555 #endif
556 };
557 
558 struct dev_pm_info {
559 	pm_message_t		power_state;
560 	unsigned int		can_wakeup:1;
561 	unsigned int		async_suspend:1;
562 	bool			is_prepared:1;	/* Owned by the PM core */
563 	bool			is_suspended:1;	/* Ditto */
564 	bool			is_noirq_suspended:1;
565 	bool			is_late_suspended:1;
566 	bool			ignore_children:1;
567 	bool			early_init:1;	/* Owned by the PM core */
568 	bool			direct_complete:1;	/* Owned by the PM core */
569 	spinlock_t		lock;
570 #ifdef CONFIG_PM_SLEEP
571 	struct list_head	entry;
572 	struct completion	completion;
573 	struct wakeup_source	*wakeup;
574 	bool			wakeup_path:1;
575 	bool			syscore:1;
576 #else
577 	unsigned int		should_wakeup:1;
578 #endif
579 #ifdef CONFIG_PM_RUNTIME
580 	struct timer_list	suspend_timer;
581 	unsigned long		timer_expires;
582 	struct work_struct	work;
583 	wait_queue_head_t	wait_queue;
584 	atomic_t		usage_count;
585 	atomic_t		child_count;
586 	unsigned int		disable_depth:3;
587 	unsigned int		idle_notification:1;
588 	unsigned int		request_pending:1;
589 	unsigned int		deferred_resume:1;
590 	unsigned int		run_wake:1;
591 	unsigned int		runtime_auto:1;
592 	unsigned int		no_callbacks:1;
593 	unsigned int		irq_safe:1;
594 	unsigned int		use_autosuspend:1;
595 	unsigned int		timer_autosuspends:1;
596 	unsigned int		memalloc_noio:1;
597 	enum rpm_request	request;
598 	enum rpm_status		runtime_status;
599 	int			runtime_error;
600 	int			autosuspend_delay;
601 	unsigned long		last_busy;
602 	unsigned long		active_jiffies;
603 	unsigned long		suspended_jiffies;
604 	unsigned long		accounting_timestamp;
605 #endif
606 	struct pm_subsys_data	*subsys_data;  /* Owned by the subsystem. */
607 	void (*set_latency_tolerance)(struct device *, s32);
608 	struct dev_pm_qos	*qos;
609 };
610 
611 extern void update_pm_runtime_accounting(struct device *dev);
612 extern int dev_pm_get_subsys_data(struct device *dev);
613 extern int dev_pm_put_subsys_data(struct device *dev);
614 
615 /*
616  * Power domains provide callbacks that are executed during system suspend,
617  * hibernation, system resume and during runtime PM transitions along with
618  * subsystem-level and driver-level callbacks.
619  */
620 struct dev_pm_domain {
621 	struct dev_pm_ops	ops;
622 };
623 
624 /*
625  * The PM_EVENT_ messages are also used by drivers implementing the legacy
626  * suspend framework, based on the ->suspend() and ->resume() callbacks common
627  * for suspend and hibernation transitions, according to the rules below.
628  */
629 
630 /* Necessary, because several drivers use PM_EVENT_PRETHAW */
631 #define PM_EVENT_PRETHAW PM_EVENT_QUIESCE
632 
633 /*
634  * One transition is triggered by resume(), after a suspend() call; the
635  * message is implicit:
636  *
637  * ON		Driver starts working again, responding to hardware events
638  *		and software requests.  The hardware may have gone through
639  *		a power-off reset, or it may have maintained state from the
640  *		previous suspend() which the driver will rely on while
641  *		resuming.  On most platforms, there are no restrictions on
642  *		availability of resources like clocks during resume().
643  *
644  * Other transitions are triggered by messages sent using suspend().  All
645  * these transitions quiesce the driver, so that I/O queues are inactive.
646  * That commonly entails turning off IRQs and DMA; there may be rules
647  * about how to quiesce that are specific to the bus or the device's type.
648  * (For example, network drivers mark the link state.)  Other details may
649  * differ according to the message:
650  *
651  * SUSPEND	Quiesce, enter a low power device state appropriate for
652  *		the upcoming system state (such as PCI_D3hot), and enable
653  *		wakeup events as appropriate.
654  *
655  * HIBERNATE	Enter a low power device state appropriate for the hibernation
656  *		state (eg. ACPI S4) and enable wakeup events as appropriate.
657  *
658  * FREEZE	Quiesce operations so that a consistent image can be saved;
659  *		but do NOT otherwise enter a low power device state, and do
660  *		NOT emit system wakeup events.
661  *
662  * PRETHAW	Quiesce as if for FREEZE; additionally, prepare for restoring
663  *		the system from a snapshot taken after an earlier FREEZE.
664  *		Some drivers will need to reset their hardware state instead
665  *		of preserving it, to ensure that it's never mistaken for the
666  *		state which that earlier snapshot had set up.
667  *
668  * A minimally power-aware driver treats all messages as SUSPEND, fully
669  * reinitializes its device during resume() -- whether or not it was reset
670  * during the suspend/resume cycle -- and can't issue wakeup events.
671  *
672  * More power-aware drivers may also use low power states at runtime as
673  * well as during system sleep states like PM_SUSPEND_STANDBY.  They may
674  * be able to use wakeup events to exit from runtime low-power states,
675  * or from system low-power states such as standby or suspend-to-RAM.
676  */
677 
678 #ifdef CONFIG_PM_SLEEP
679 extern void device_pm_lock(void);
680 extern void dpm_resume_start(pm_message_t state);
681 extern void dpm_resume_end(pm_message_t state);
682 extern void dpm_resume(pm_message_t state);
683 extern void dpm_complete(pm_message_t state);
684 
685 extern void device_pm_unlock(void);
686 extern int dpm_suspend_end(pm_message_t state);
687 extern int dpm_suspend_start(pm_message_t state);
688 extern int dpm_suspend(pm_message_t state);
689 extern int dpm_prepare(pm_message_t state);
690 
691 extern void __suspend_report_result(const char *function, void *fn, int ret);
692 
693 #define suspend_report_result(fn, ret)					\
694 	do {								\
695 		__suspend_report_result(__func__, fn, ret);		\
696 	} while (0)
697 
698 extern int device_pm_wait_for_dev(struct device *sub, struct device *dev);
699 extern void dpm_for_each_dev(void *data, void (*fn)(struct device *, void *));
700 
701 extern int pm_generic_prepare(struct device *dev);
702 extern int pm_generic_suspend_late(struct device *dev);
703 extern int pm_generic_suspend_noirq(struct device *dev);
704 extern int pm_generic_suspend(struct device *dev);
705 extern int pm_generic_resume_early(struct device *dev);
706 extern int pm_generic_resume_noirq(struct device *dev);
707 extern int pm_generic_resume(struct device *dev);
708 extern int pm_generic_freeze_noirq(struct device *dev);
709 extern int pm_generic_freeze_late(struct device *dev);
710 extern int pm_generic_freeze(struct device *dev);
711 extern int pm_generic_thaw_noirq(struct device *dev);
712 extern int pm_generic_thaw_early(struct device *dev);
713 extern int pm_generic_thaw(struct device *dev);
714 extern int pm_generic_restore_noirq(struct device *dev);
715 extern int pm_generic_restore_early(struct device *dev);
716 extern int pm_generic_restore(struct device *dev);
717 extern int pm_generic_poweroff_noirq(struct device *dev);
718 extern int pm_generic_poweroff_late(struct device *dev);
719 extern int pm_generic_poweroff(struct device *dev);
720 extern void pm_generic_complete(struct device *dev);
721 
722 #else /* !CONFIG_PM_SLEEP */
723 
724 #define device_pm_lock() do {} while (0)
725 #define device_pm_unlock() do {} while (0)
726 
727 static inline int dpm_suspend_start(pm_message_t state)
728 {
729 	return 0;
730 }
731 
732 #define suspend_report_result(fn, ret)		do {} while (0)
733 
734 static inline int device_pm_wait_for_dev(struct device *a, struct device *b)
735 {
736 	return 0;
737 }
738 
739 static inline void dpm_for_each_dev(void *data, void (*fn)(struct device *, void *))
740 {
741 }
742 
743 #define pm_generic_prepare		NULL
744 #define pm_generic_suspend_late		NULL
745 #define pm_generic_suspend_noirq	NULL
746 #define pm_generic_suspend		NULL
747 #define pm_generic_resume_early		NULL
748 #define pm_generic_resume_noirq		NULL
749 #define pm_generic_resume		NULL
750 #define pm_generic_freeze_noirq		NULL
751 #define pm_generic_freeze_late		NULL
752 #define pm_generic_freeze		NULL
753 #define pm_generic_thaw_noirq		NULL
754 #define pm_generic_thaw_early		NULL
755 #define pm_generic_thaw			NULL
756 #define pm_generic_restore_noirq	NULL
757 #define pm_generic_restore_early	NULL
758 #define pm_generic_restore		NULL
759 #define pm_generic_poweroff_noirq	NULL
760 #define pm_generic_poweroff_late	NULL
761 #define pm_generic_poweroff		NULL
762 #define pm_generic_complete		NULL
763 #endif /* !CONFIG_PM_SLEEP */
764 
765 /* How to reorder dpm_list after device_move() */
766 enum dpm_order {
767 	DPM_ORDER_NONE,
768 	DPM_ORDER_DEV_AFTER_PARENT,
769 	DPM_ORDER_PARENT_BEFORE_DEV,
770 	DPM_ORDER_DEV_LAST,
771 };
772 
773 #endif /* _LINUX_PM_H */
774