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1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  *  pm.h - Power management interface
4  *
5  *  Copyright (C) 2000 Andrew Henroid
6  */
7 
8 #ifndef _LINUX_PM_H
9 #define _LINUX_PM_H
10 
11 #include <linux/list.h>
12 #include <linux/workqueue.h>
13 #include <linux/spinlock.h>
14 #include <linux/wait.h>
15 #include <linux/timer.h>
16 #include <linux/hrtimer.h>
17 #include <linux/completion.h>
18 #include <linux/android_kabi.h>
19 
20 /*
21  * Callbacks for platform drivers to implement.
22  */
23 extern void (*pm_power_off)(void);
24 extern void (*pm_power_off_prepare)(void);
25 
26 struct device; /* we have a circular dep with device.h */
27 #ifdef CONFIG_VT_CONSOLE_SLEEP
28 extern void pm_vt_switch_required(struct device *dev, bool required);
29 extern void pm_vt_switch_unregister(struct device *dev);
30 #else
pm_vt_switch_required(struct device * dev,bool required)31 static inline void pm_vt_switch_required(struct device *dev, bool required)
32 {
33 }
pm_vt_switch_unregister(struct device * dev)34 static inline void pm_vt_switch_unregister(struct device *dev)
35 {
36 }
37 #endif /* CONFIG_VT_CONSOLE_SLEEP */
38 
39 /*
40  * Device power management
41  */
42 
43 struct device;
44 
45 #ifdef CONFIG_PM
46 extern const char power_group_name[];		/* = "power" */
47 #else
48 #define power_group_name	NULL
49 #endif
50 
51 typedef struct pm_message {
52 	int event;
53 } pm_message_t;
54 
55 /**
56  * struct dev_pm_ops - device PM callbacks.
57  *
58  * @prepare: The principal role of this callback is to prevent new children of
59  *	the device from being registered after it has returned (the driver's
60  *	subsystem and generally the rest of the kernel is supposed to prevent
61  *	new calls to the probe method from being made too once @prepare() has
62  *	succeeded).  If @prepare() detects a situation it cannot handle (e.g.
63  *	registration of a child already in progress), it may return -EAGAIN, so
64  *	that the PM core can execute it once again (e.g. after a new child has
65  *	been registered) to recover from the race condition.
66  *	This method is executed for all kinds of suspend transitions and is
67  *	followed by one of the suspend callbacks: @suspend(), @freeze(), or
68  *	@poweroff().  If the transition is a suspend to memory or standby (that
69  *	is, not related to hibernation), the return value of @prepare() may be
70  *	used to indicate to the PM core to leave the device in runtime suspend
71  *	if applicable.  Namely, if @prepare() returns a positive number, the PM
72  *	core will understand that as a declaration that the device appears to be
73  *	runtime-suspended and it may be left in that state during the entire
74  *	transition and during the subsequent resume if all of its descendants
75  *	are left in runtime suspend too.  If that happens, @complete() will be
76  *	executed directly after @prepare() and it must ensure the proper
77  *	functioning of the device after the system resume.
78  *	The PM core executes subsystem-level @prepare() for all devices before
79  *	starting to invoke suspend callbacks for any of them, so generally
80  *	devices may be assumed to be functional or to respond to runtime resume
81  *	requests while @prepare() is being executed.  However, device drivers
82  *	may NOT assume anything about the availability of user space at that
83  *	time and it is NOT valid to request firmware from within @prepare()
84  *	(it's too late to do that).  It also is NOT valid to allocate
85  *	substantial amounts of memory from @prepare() in the GFP_KERNEL mode.
86  *	[To work around these limitations, drivers may register suspend and
87  *	hibernation notifiers to be executed before the freezing of tasks.]
88  *
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() or
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
95  *	suspend earlier).
96  *	The PM core executes subsystem-level @complete() after it has executed
97  *	the appropriate resume callbacks for all devices.  If the corresponding
98  *	@prepare() at the beginning of the suspend transition returned a
99  *	positive number and the device was left in runtime suspend (without
100  *	executing any suspend and resume callbacks for it), @complete() will be
101  *	the only callback executed for the device during resume.  In that case,
102  *	@complete() must be prepared to do whatever is necessary to ensure the
103  *	proper functioning of the device after the system resume.  To this end,
104  *	@complete() can check the power.direct_complete flag of the device to
105  *	learn whether (unset) or not (set) the previous suspend and resume
106  *	callbacks have been executed for it.
107  *
108  * @suspend: Executed before putting the system into a sleep state in which the
109  *	contents of main memory are preserved.  The exact action to perform
110  *	depends on the device's subsystem (PM domain, device type, class or bus
111  *	type), but generally the device must be quiescent after subsystem-level
112  *	@suspend() has returned, so that it doesn't do any I/O or DMA.
113  *	Subsystem-level @suspend() is executed for all devices after invoking
114  *	subsystem-level @prepare() for all of them.
115  *
116  * @suspend_late: Continue operations started by @suspend().  For a number of
117  *	devices @suspend_late() may point to the same callback routine as the
118  *	runtime suspend callback.
119  *
120  * @resume: Executed after waking the system up from a sleep state in which the
121  *	contents of main memory were preserved.  The exact action to perform
122  *	depends on the device's subsystem, but generally the driver is expected
123  *	to start working again, responding to hardware events and software
124  *	requests (the device itself may be left in a low-power state, waiting
125  *	for a runtime resume to occur).  The state of the device at the time its
126  *	driver's @resume() callback is run depends on the platform and subsystem
127  *	the device belongs to.  On most platforms, there are no restrictions on
128  *	availability of resources like clocks during @resume().
129  *	Subsystem-level @resume() is executed for all devices after invoking
130  *	subsystem-level @resume_noirq() for all of them.
131  *
132  * @resume_early: Prepare to execute @resume().  For a number of devices
133  *	@resume_early() may point to the same callback routine as the runtime
134  *	resume callback.
135  *
136  * @freeze: Hibernation-specific, executed before creating a hibernation image.
137  *	Analogous to @suspend(), but it should not enable the device to signal
138  *	wakeup events or change its power state.  The majority of subsystems
139  *	(with the notable exception of the PCI bus type) expect the driver-level
140  *	@freeze() to save the device settings in memory to be used by @restore()
141  *	during the subsequent resume from hibernation.
142  *	Subsystem-level @freeze() is executed for all devices after invoking
143  *	subsystem-level @prepare() for all of them.
144  *
145  * @freeze_late: Continue operations started by @freeze().  Analogous to
146  *	@suspend_late(), but it should not enable the device to signal wakeup
147  *	events or change its power state.
148  *
149  * @thaw: Hibernation-specific, executed after creating a hibernation image OR
150  *	if the creation of an image has failed.  Also executed after a failing
151  *	attempt to restore the contents of main memory from such an image.
152  *	Undo the changes made by the preceding @freeze(), so the device can be
153  *	operated in the same way as immediately before the call to @freeze().
154  *	Subsystem-level @thaw() is executed for all devices after invoking
155  *	subsystem-level @thaw_noirq() for all of them.  It also may be executed
156  *	directly after @freeze() in case of a transition error.
157  *
158  * @thaw_early: Prepare to execute @thaw().  Undo the changes made by the
159  *	preceding @freeze_late().
160  *
161  * @poweroff: Hibernation-specific, executed after saving a hibernation image.
162  *	Analogous to @suspend(), but it need not save the device's settings in
163  *	memory.
164  *	Subsystem-level @poweroff() is executed for all devices after invoking
165  *	subsystem-level @prepare() for all of them.
166  *
167  * @poweroff_late: Continue operations started by @poweroff().  Analogous to
168  *	@suspend_late(), but it need not save the device's settings in memory.
169  *
170  * @restore: Hibernation-specific, executed after restoring the contents of main
171  *	memory from a hibernation image, analogous to @resume().
172  *
173  * @restore_early: Prepare to execute @restore(), analogous to @resume_early().
174  *
175  * @suspend_noirq: Complete the actions started by @suspend().  Carry out any
176  *	additional operations required for suspending the device that might be
177  *	racing with its driver's interrupt handler, which is guaranteed not to
178  *	run while @suspend_noirq() is being executed.
179  *	It generally is expected that the device will be in a low-power state
180  *	(appropriate for the target system sleep state) after subsystem-level
181  *	@suspend_noirq() has returned successfully.  If the device can generate
182  *	system wakeup signals and is enabled to wake up the system, it should be
183  *	configured to do so at that time.  However, depending on the platform
184  *	and device's subsystem, @suspend() or @suspend_late() may be allowed to
185  *	put the device into the low-power state and configure it to generate
186  *	wakeup signals, in which case it generally is not necessary to define
187  *	@suspend_noirq().
188  *
189  * @resume_noirq: Prepare for the execution of @resume() by carrying out any
190  *	operations required for resuming the device that might be racing with
191  *	its driver's interrupt handler, which is guaranteed not to run while
192  *	@resume_noirq() is being executed.
193  *
194  * @freeze_noirq: Complete the actions started by @freeze().  Carry out any
195  *	additional operations required for freezing the device that might be
196  *	racing with its driver's interrupt handler, which is guaranteed not to
197  *	run while @freeze_noirq() is being executed.
198  *	The power state of the device should not be changed by either @freeze(),
199  *	or @freeze_late(), or @freeze_noirq() and it should not be configured to
200  *	signal system wakeup by any of these callbacks.
201  *
202  * @thaw_noirq: Prepare for the execution of @thaw() by carrying out any
203  *	operations required for thawing the device that might be racing with its
204  *	driver's interrupt handler, which is guaranteed not to run while
205  *	@thaw_noirq() is being executed.
206  *
207  * @poweroff_noirq: Complete the actions started by @poweroff().  Analogous to
208  *	@suspend_noirq(), but it need not save the device's settings in memory.
209  *
210  * @restore_noirq: Prepare for the execution of @restore() by carrying out any
211  *	operations required for thawing the device that might be racing with its
212  *	driver's interrupt handler, which is guaranteed not to run while
213  *	@restore_noirq() is being executed.  Analogous to @resume_noirq().
214  *
215  * @runtime_suspend: Prepare the device for a condition in which it won't be
216  *	able to communicate with the CPU(s) and RAM due to power management.
217  *	This need not mean that the device should be put into a low-power state.
218  *	For example, if the device is behind a link which is about to be turned
219  *	off, the device may remain at full power.  If the device does go to low
220  *	power and is capable of generating runtime wakeup events, remote wakeup
221  *	(i.e., a hardware mechanism allowing the device to request a change of
222  *	its power state via an interrupt) should be enabled for it.
223  *
224  * @runtime_resume: Put the device into the fully active state in response to a
225  *	wakeup event generated by hardware or at the request of software.  If
226  *	necessary, put the device into the full-power state and restore its
227  *	registers, so that it is fully operational.
228  *
229  * @runtime_idle: Device appears to be inactive and it might be put into a
230  *	low-power state if all of the necessary conditions are satisfied.
231  *	Check these conditions, and return 0 if it's appropriate to let the PM
232  *	core queue a suspend request for the device.
233  *
234  * Several device power state transitions are externally visible, affecting
235  * the state of pending I/O queues and (for drivers that touch hardware)
236  * interrupts, wakeups, DMA, and other hardware state.  There may also be
237  * internal transitions to various low-power modes which are transparent
238  * to the rest of the driver stack (such as a driver that's ON gating off
239  * clocks which are not in active use).
240  *
241  * The externally visible transitions are handled with the help of callbacks
242  * included in this structure in such a way that, typically, two levels of
243  * callbacks are involved.  First, the PM core executes callbacks provided by PM
244  * domains, device types, classes and bus types.  They are the subsystem-level
245  * callbacks expected to execute callbacks provided by device drivers, although
246  * they may choose not to do that.  If the driver callbacks are executed, they
247  * have to collaborate with the subsystem-level callbacks to achieve the goals
248  * appropriate for the given system transition, given transition phase and the
249  * subsystem the device belongs to.
250  *
251  * All of the above callbacks, except for @complete(), return error codes.
252  * However, the error codes returned by @resume(), @thaw(), @restore(),
253  * @resume_noirq(), @thaw_noirq(), and @restore_noirq(), do not cause the PM
254  * core to abort the resume transition during which they are returned.  The
255  * error codes returned in those cases are only printed to the system logs for
256  * debugging purposes.  Still, it is recommended that drivers only return error
257  * codes from their resume methods in case of an unrecoverable failure (i.e.
258  * when the device being handled refuses to resume and becomes unusable) to
259  * allow the PM core to be modified in the future, so that it can avoid
260  * attempting to handle devices that failed to resume and their children.
261  *
262  * It is allowed to unregister devices while the above callbacks are being
263  * executed.  However, a callback routine MUST NOT try to unregister the device
264  * it was called for, although it may unregister children of that device (for
265  * example, if it detects that a child was unplugged while the system was
266  * asleep).
267  *
268  * There also are callbacks related to runtime power management of devices.
269  * Again, as a rule these callbacks are executed by the PM core for subsystems
270  * (PM domains, device types, classes and bus types) and the subsystem-level
271  * callbacks are expected to invoke the driver callbacks.  Moreover, the exact
272  * actions to be performed by a device driver's callbacks generally depend on
273  * the platform and subsystem the device belongs to.
274  *
275  * Refer to Documentation/power/runtime_pm.rst for more information about the
276  * role of the @runtime_suspend(), @runtime_resume() and @runtime_idle()
277  * callbacks in device runtime power management.
278  */
279 struct dev_pm_ops {
280 	int (*prepare)(struct device *dev);
281 	void (*complete)(struct device *dev);
282 	int (*suspend)(struct device *dev);
283 	int (*resume)(struct device *dev);
284 	int (*freeze)(struct device *dev);
285 	int (*thaw)(struct device *dev);
286 	int (*poweroff)(struct device *dev);
287 	int (*restore)(struct device *dev);
288 	int (*suspend_late)(struct device *dev);
289 	int (*resume_early)(struct device *dev);
290 	int (*freeze_late)(struct device *dev);
291 	int (*thaw_early)(struct device *dev);
292 	int (*poweroff_late)(struct device *dev);
293 	int (*restore_early)(struct device *dev);
294 	int (*suspend_noirq)(struct device *dev);
295 	int (*resume_noirq)(struct device *dev);
296 	int (*freeze_noirq)(struct device *dev);
297 	int (*thaw_noirq)(struct device *dev);
298 	int (*poweroff_noirq)(struct device *dev);
299 	int (*restore_noirq)(struct device *dev);
300 	int (*runtime_suspend)(struct device *dev);
301 	int (*runtime_resume)(struct device *dev);
302 	int (*runtime_idle)(struct device *dev);
303 
304 	ANDROID_KABI_RESERVE(1);
305 };
306 
307 #ifdef CONFIG_PM_SLEEP
308 #define SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
309 	.suspend = suspend_fn, \
310 	.resume = resume_fn, \
311 	.freeze = suspend_fn, \
312 	.thaw = resume_fn, \
313 	.poweroff = suspend_fn, \
314 	.restore = resume_fn,
315 #else
316 #define SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn)
317 #endif
318 
319 #ifdef CONFIG_PM_SLEEP
320 #define SET_LATE_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
321 	.suspend_late = suspend_fn, \
322 	.resume_early = resume_fn, \
323 	.freeze_late = suspend_fn, \
324 	.thaw_early = resume_fn, \
325 	.poweroff_late = suspend_fn, \
326 	.restore_early = resume_fn,
327 #else
328 #define SET_LATE_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn)
329 #endif
330 
331 #ifdef CONFIG_PM_SLEEP
332 #define SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
333 	.suspend_noirq = suspend_fn, \
334 	.resume_noirq = resume_fn, \
335 	.freeze_noirq = suspend_fn, \
336 	.thaw_noirq = resume_fn, \
337 	.poweroff_noirq = suspend_fn, \
338 	.restore_noirq = resume_fn,
339 #else
340 #define SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn)
341 #endif
342 
343 #ifdef CONFIG_PM
344 #define SET_RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn) \
345 	.runtime_suspend = suspend_fn, \
346 	.runtime_resume = resume_fn, \
347 	.runtime_idle = idle_fn,
348 #else
349 #define SET_RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn)
350 #endif
351 
352 /*
353  * Use this if you want to use the same suspend and resume callbacks for suspend
354  * to RAM and hibernation.
355  */
356 #define SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn) \
357 const struct dev_pm_ops __maybe_unused name = { \
358 	SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
359 }
360 
361 /*
362  * Use this for defining a set of PM operations to be used in all situations
363  * (system suspend, hibernation or runtime PM).
364  * NOTE: In general, system suspend callbacks, .suspend() and .resume(), should
365  * be different from the corresponding runtime PM callbacks, .runtime_suspend(),
366  * and .runtime_resume(), because .runtime_suspend() always works on an already
367  * quiescent device, while .suspend() should assume that the device may be doing
368  * something when it is called (it should ensure that the device will be
369  * quiescent after it has returned).  Therefore it's better to point the "late"
370  * suspend and "early" resume callback pointers, .suspend_late() and
371  * .resume_early(), to the same routines as .runtime_suspend() and
372  * .runtime_resume(), respectively (and analogously for hibernation).
373  */
374 #define UNIVERSAL_DEV_PM_OPS(name, suspend_fn, resume_fn, idle_fn) \
375 const struct dev_pm_ops __maybe_unused name = { \
376 	SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
377 	SET_RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn) \
378 }
379 
380 #ifdef CONFIG_PM
381 #define pm_ptr(_ptr) (_ptr)
382 #else
383 #define pm_ptr(_ptr) NULL
384 #endif
385 
386 /*
387  * PM_EVENT_ messages
388  *
389  * The following PM_EVENT_ messages are defined for the internal use of the PM
390  * core, in order to provide a mechanism allowing the high level suspend and
391  * hibernation code to convey the necessary information to the device PM core
392  * code:
393  *
394  * ON		No transition.
395  *
396  * FREEZE	System is going to hibernate, call ->prepare() and ->freeze()
397  *		for all devices.
398  *
399  * SUSPEND	System is going to suspend, call ->prepare() and ->suspend()
400  *		for all devices.
401  *
402  * HIBERNATE	Hibernation image has been saved, call ->prepare() and
403  *		->poweroff() for all devices.
404  *
405  * QUIESCE	Contents of main memory are going to be restored from a (loaded)
406  *		hibernation image, call ->prepare() and ->freeze() for all
407  *		devices.
408  *
409  * RESUME	System is resuming, call ->resume() and ->complete() for all
410  *		devices.
411  *
412  * THAW		Hibernation image has been created, call ->thaw() and
413  *		->complete() for all devices.
414  *
415  * RESTORE	Contents of main memory have been restored from a hibernation
416  *		image, call ->restore() and ->complete() for all devices.
417  *
418  * RECOVER	Creation of a hibernation image or restoration of the main
419  *		memory contents from a hibernation image has failed, call
420  *		->thaw() and ->complete() for all devices.
421  *
422  * The following PM_EVENT_ messages are defined for internal use by
423  * kernel subsystems.  They are never issued by the PM core.
424  *
425  * USER_SUSPEND		Manual selective suspend was issued by userspace.
426  *
427  * USER_RESUME		Manual selective resume was issued by userspace.
428  *
429  * REMOTE_WAKEUP	Remote-wakeup request was received from the device.
430  *
431  * AUTO_SUSPEND		Automatic (device idle) runtime suspend was
432  *			initiated by the subsystem.
433  *
434  * AUTO_RESUME		Automatic (device needed) runtime resume was
435  *			requested by a driver.
436  */
437 
438 #define PM_EVENT_INVALID	(-1)
439 #define PM_EVENT_ON		0x0000
440 #define PM_EVENT_FREEZE		0x0001
441 #define PM_EVENT_SUSPEND	0x0002
442 #define PM_EVENT_HIBERNATE	0x0004
443 #define PM_EVENT_QUIESCE	0x0008
444 #define PM_EVENT_RESUME		0x0010
445 #define PM_EVENT_THAW		0x0020
446 #define PM_EVENT_RESTORE	0x0040
447 #define PM_EVENT_RECOVER	0x0080
448 #define PM_EVENT_USER		0x0100
449 #define PM_EVENT_REMOTE		0x0200
450 #define PM_EVENT_AUTO		0x0400
451 
452 #define PM_EVENT_SLEEP		(PM_EVENT_SUSPEND | PM_EVENT_HIBERNATE)
453 #define PM_EVENT_USER_SUSPEND	(PM_EVENT_USER | PM_EVENT_SUSPEND)
454 #define PM_EVENT_USER_RESUME	(PM_EVENT_USER | PM_EVENT_RESUME)
455 #define PM_EVENT_REMOTE_RESUME	(PM_EVENT_REMOTE | PM_EVENT_RESUME)
456 #define PM_EVENT_AUTO_SUSPEND	(PM_EVENT_AUTO | PM_EVENT_SUSPEND)
457 #define PM_EVENT_AUTO_RESUME	(PM_EVENT_AUTO | PM_EVENT_RESUME)
458 
459 #define PMSG_INVALID	((struct pm_message){ .event = PM_EVENT_INVALID, })
460 #define PMSG_ON		((struct pm_message){ .event = PM_EVENT_ON, })
461 #define PMSG_FREEZE	((struct pm_message){ .event = PM_EVENT_FREEZE, })
462 #define PMSG_QUIESCE	((struct pm_message){ .event = PM_EVENT_QUIESCE, })
463 #define PMSG_SUSPEND	((struct pm_message){ .event = PM_EVENT_SUSPEND, })
464 #define PMSG_HIBERNATE	((struct pm_message){ .event = PM_EVENT_HIBERNATE, })
465 #define PMSG_RESUME	((struct pm_message){ .event = PM_EVENT_RESUME, })
466 #define PMSG_THAW	((struct pm_message){ .event = PM_EVENT_THAW, })
467 #define PMSG_RESTORE	((struct pm_message){ .event = PM_EVENT_RESTORE, })
468 #define PMSG_RECOVER	((struct pm_message){ .event = PM_EVENT_RECOVER, })
469 #define PMSG_USER_SUSPEND	((struct pm_message) \
470 					{ .event = PM_EVENT_USER_SUSPEND, })
471 #define PMSG_USER_RESUME	((struct pm_message) \
472 					{ .event = PM_EVENT_USER_RESUME, })
473 #define PMSG_REMOTE_RESUME	((struct pm_message) \
474 					{ .event = PM_EVENT_REMOTE_RESUME, })
475 #define PMSG_AUTO_SUSPEND	((struct pm_message) \
476 					{ .event = PM_EVENT_AUTO_SUSPEND, })
477 #define PMSG_AUTO_RESUME	((struct pm_message) \
478 					{ .event = PM_EVENT_AUTO_RESUME, })
479 
480 #define PMSG_IS_AUTO(msg)	(((msg).event & PM_EVENT_AUTO) != 0)
481 
482 /*
483  * Device run-time power management status.
484  *
485  * These status labels are used internally by the PM core to indicate the
486  * current status of a device with respect to the PM core operations.  They do
487  * not reflect the actual power state of the device or its status as seen by the
488  * driver.
489  *
490  * RPM_ACTIVE		Device is fully operational.  Indicates that the device
491  *			bus type's ->runtime_resume() callback has completed
492  *			successfully.
493  *
494  * RPM_SUSPENDED	Device bus type's ->runtime_suspend() callback has
495  *			completed successfully.  The device is regarded as
496  *			suspended.
497  *
498  * RPM_RESUMING		Device bus type's ->runtime_resume() callback is being
499  *			executed.
500  *
501  * RPM_SUSPENDING	Device bus type's ->runtime_suspend() callback is being
502  *			executed.
503  */
504 
505 enum rpm_status {
506 	RPM_ACTIVE = 0,
507 	RPM_RESUMING,
508 	RPM_SUSPENDED,
509 	RPM_SUSPENDING,
510 };
511 
512 /*
513  * Device run-time power management request types.
514  *
515  * RPM_REQ_NONE		Do nothing.
516  *
517  * RPM_REQ_IDLE		Run the device bus type's ->runtime_idle() callback
518  *
519  * RPM_REQ_SUSPEND	Run the device bus type's ->runtime_suspend() callback
520  *
521  * RPM_REQ_AUTOSUSPEND	Same as RPM_REQ_SUSPEND, but not until the device has
522  *			been inactive for as long as power.autosuspend_delay
523  *
524  * RPM_REQ_RESUME	Run the device bus type's ->runtime_resume() callback
525  */
526 
527 enum rpm_request {
528 	RPM_REQ_NONE = 0,
529 	RPM_REQ_IDLE,
530 	RPM_REQ_SUSPEND,
531 	RPM_REQ_AUTOSUSPEND,
532 	RPM_REQ_RESUME,
533 };
534 
535 struct wakeup_source;
536 struct wake_irq;
537 struct pm_domain_data;
538 
539 struct pm_subsys_data {
540 	spinlock_t lock;
541 	unsigned int refcount;
542 #ifdef CONFIG_PM_CLK
543 	struct list_head clock_list;
544 #endif
545 #ifdef CONFIG_PM_GENERIC_DOMAINS
546 	struct pm_domain_data *domain_data;
547 #endif
548 };
549 
550 /*
551  * Driver flags to control system suspend/resume behavior.
552  *
553  * These flags can be set by device drivers at the probe time.  They need not be
554  * cleared by the drivers as the driver core will take care of that.
555  *
556  * NO_DIRECT_COMPLETE: Do not apply direct-complete optimization to the device.
557  * SMART_PREPARE: Take the driver ->prepare callback return value into account.
558  * SMART_SUSPEND: Avoid resuming the device from runtime suspend.
559  * MAY_SKIP_RESUME: Allow driver "noirq" and "early" callbacks to be skipped.
560  *
561  * See Documentation/driver-api/pm/devices.rst for details.
562  */
563 #define DPM_FLAG_NO_DIRECT_COMPLETE	BIT(0)
564 #define DPM_FLAG_SMART_PREPARE		BIT(1)
565 #define DPM_FLAG_SMART_SUSPEND		BIT(2)
566 #define DPM_FLAG_MAY_SKIP_RESUME	BIT(3)
567 
568 struct dev_pm_info {
569 	pm_message_t		power_state;
570 	unsigned int		can_wakeup:1;
571 	unsigned int		async_suspend:1;
572 	bool			in_dpm_list:1;	/* Owned by the PM core */
573 	bool			is_prepared:1;	/* Owned by the PM core */
574 	bool			is_suspended:1;	/* Ditto */
575 	bool			is_noirq_suspended:1;
576 	bool			is_late_suspended:1;
577 	bool			no_pm:1;
578 	bool			early_init:1;	/* Owned by the PM core */
579 	bool			direct_complete:1;	/* Owned by the PM core */
580 	u32			driver_flags;
581 	spinlock_t		lock;
582 #ifdef CONFIG_PM_SLEEP
583 	struct list_head	entry;
584 	struct completion	completion;
585 	struct wakeup_source	*wakeup;
586 	bool			wakeup_path:1;
587 	bool			syscore:1;
588 	bool			no_pm_callbacks:1;	/* Owned by the PM core */
589 	unsigned int		must_resume:1;	/* Owned by the PM core */
590 	unsigned int		may_skip_resume:1;	/* Set by subsystems */
591 #else
592 	unsigned int		should_wakeup:1;
593 #endif
594 #ifdef CONFIG_PM
595 	struct hrtimer		suspend_timer;
596 	u64			timer_expires;
597 	struct work_struct	work;
598 	wait_queue_head_t	wait_queue;
599 	struct wake_irq		*wakeirq;
600 	atomic_t		usage_count;
601 	atomic_t		child_count;
602 	unsigned int		disable_depth:3;
603 	unsigned int		idle_notification:1;
604 	unsigned int		request_pending:1;
605 	unsigned int		deferred_resume:1;
606 	unsigned int		needs_force_resume:1;
607 	unsigned int		runtime_auto:1;
608 	bool			ignore_children:1;
609 	unsigned int		no_callbacks:1;
610 	unsigned int		irq_safe:1;
611 	unsigned int		use_autosuspend:1;
612 	unsigned int		timer_autosuspends:1;
613 	unsigned int		memalloc_noio:1;
614 	unsigned int		links_count;
615 	enum rpm_request	request;
616 	enum rpm_status		runtime_status;
617 	int			runtime_error;
618 	int			autosuspend_delay;
619 	u64			last_busy;
620 	u64			active_time;
621 	u64			suspended_time;
622 	u64			accounting_timestamp;
623 #endif
624 	struct pm_subsys_data	*subsys_data;  /* Owned by the subsystem. */
625 	void (*set_latency_tolerance)(struct device *, s32);
626 	struct dev_pm_qos	*qos;
627 
628 	ANDROID_KABI_RESERVE(1);
629 	ANDROID_KABI_RESERVE(2);
630 };
631 
632 extern int dev_pm_get_subsys_data(struct device *dev);
633 extern void dev_pm_put_subsys_data(struct device *dev);
634 
635 /**
636  * struct dev_pm_domain - power management domain representation.
637  *
638  * @ops: Power management operations associated with this domain.
639  * @start: Called when a user needs to start the device via the domain.
640  * @detach: Called when removing a device from the domain.
641  * @activate: Called before executing probe routines for bus types and drivers.
642  * @sync: Called after successful driver probe.
643  * @dismiss: Called after unsuccessful driver probe and after driver removal.
644  *
645  * Power domains provide callbacks that are executed during system suspend,
646  * hibernation, system resume and during runtime PM transitions instead of
647  * subsystem-level and driver-level callbacks.
648  */
649 struct dev_pm_domain {
650 	struct dev_pm_ops	ops;
651 	int (*start)(struct device *dev);
652 	void (*detach)(struct device *dev, bool power_off);
653 	int (*activate)(struct device *dev);
654 	void (*sync)(struct device *dev);
655 	void (*dismiss)(struct device *dev);
656 
657 	ANDROID_KABI_RESERVE(1);
658 };
659 
660 /*
661  * The PM_EVENT_ messages are also used by drivers implementing the legacy
662  * suspend framework, based on the ->suspend() and ->resume() callbacks common
663  * for suspend and hibernation transitions, according to the rules below.
664  */
665 
666 /* Necessary, because several drivers use PM_EVENT_PRETHAW */
667 #define PM_EVENT_PRETHAW PM_EVENT_QUIESCE
668 
669 /*
670  * One transition is triggered by resume(), after a suspend() call; the
671  * message is implicit:
672  *
673  * ON		Driver starts working again, responding to hardware events
674  *		and software requests.  The hardware may have gone through
675  *		a power-off reset, or it may have maintained state from the
676  *		previous suspend() which the driver will rely on while
677  *		resuming.  On most platforms, there are no restrictions on
678  *		availability of resources like clocks during resume().
679  *
680  * Other transitions are triggered by messages sent using suspend().  All
681  * these transitions quiesce the driver, so that I/O queues are inactive.
682  * That commonly entails turning off IRQs and DMA; there may be rules
683  * about how to quiesce that are specific to the bus or the device's type.
684  * (For example, network drivers mark the link state.)  Other details may
685  * differ according to the message:
686  *
687  * SUSPEND	Quiesce, enter a low power device state appropriate for
688  *		the upcoming system state (such as PCI_D3hot), and enable
689  *		wakeup events as appropriate.
690  *
691  * HIBERNATE	Enter a low power device state appropriate for the hibernation
692  *		state (eg. ACPI S4) and enable wakeup events as appropriate.
693  *
694  * FREEZE	Quiesce operations so that a consistent image can be saved;
695  *		but do NOT otherwise enter a low power device state, and do
696  *		NOT emit system wakeup events.
697  *
698  * PRETHAW	Quiesce as if for FREEZE; additionally, prepare for restoring
699  *		the system from a snapshot taken after an earlier FREEZE.
700  *		Some drivers will need to reset their hardware state instead
701  *		of preserving it, to ensure that it's never mistaken for the
702  *		state which that earlier snapshot had set up.
703  *
704  * A minimally power-aware driver treats all messages as SUSPEND, fully
705  * reinitializes its device during resume() -- whether or not it was reset
706  * during the suspend/resume cycle -- and can't issue wakeup events.
707  *
708  * More power-aware drivers may also use low power states at runtime as
709  * well as during system sleep states like PM_SUSPEND_STANDBY.  They may
710  * be able to use wakeup events to exit from runtime low-power states,
711  * or from system low-power states such as standby or suspend-to-RAM.
712  */
713 
714 #ifdef CONFIG_PM_SLEEP
715 extern void device_pm_lock(void);
716 extern void dpm_resume_start(pm_message_t state);
717 extern void dpm_resume_end(pm_message_t state);
718 extern void dpm_resume_noirq(pm_message_t state);
719 extern void dpm_resume_early(pm_message_t state);
720 extern void dpm_resume(pm_message_t state);
721 extern void dpm_complete(pm_message_t state);
722 
723 extern void device_pm_unlock(void);
724 extern int dpm_suspend_end(pm_message_t state);
725 extern int dpm_suspend_start(pm_message_t state);
726 extern int dpm_suspend_noirq(pm_message_t state);
727 extern int dpm_suspend_late(pm_message_t state);
728 extern int dpm_suspend(pm_message_t state);
729 extern int dpm_prepare(pm_message_t state);
730 
731 extern void __suspend_report_result(const char *function, void *fn, int ret);
732 
733 #define suspend_report_result(fn, ret)					\
734 	do {								\
735 		__suspend_report_result(__func__, fn, ret);		\
736 	} while (0)
737 
738 extern int device_pm_wait_for_dev(struct device *sub, struct device *dev);
739 extern void dpm_for_each_dev(void *data, void (*fn)(struct device *, void *));
740 
741 extern int pm_generic_prepare(struct device *dev);
742 extern int pm_generic_suspend_late(struct device *dev);
743 extern int pm_generic_suspend_noirq(struct device *dev);
744 extern int pm_generic_suspend(struct device *dev);
745 extern int pm_generic_resume_early(struct device *dev);
746 extern int pm_generic_resume_noirq(struct device *dev);
747 extern int pm_generic_resume(struct device *dev);
748 extern int pm_generic_freeze_noirq(struct device *dev);
749 extern int pm_generic_freeze_late(struct device *dev);
750 extern int pm_generic_freeze(struct device *dev);
751 extern int pm_generic_thaw_noirq(struct device *dev);
752 extern int pm_generic_thaw_early(struct device *dev);
753 extern int pm_generic_thaw(struct device *dev);
754 extern int pm_generic_restore_noirq(struct device *dev);
755 extern int pm_generic_restore_early(struct device *dev);
756 extern int pm_generic_restore(struct device *dev);
757 extern int pm_generic_poweroff_noirq(struct device *dev);
758 extern int pm_generic_poweroff_late(struct device *dev);
759 extern int pm_generic_poweroff(struct device *dev);
760 extern void pm_generic_complete(struct device *dev);
761 
762 extern bool dev_pm_skip_resume(struct device *dev);
763 extern bool dev_pm_skip_suspend(struct device *dev);
764 
765 #else /* !CONFIG_PM_SLEEP */
766 
767 #define device_pm_lock() do {} while (0)
768 #define device_pm_unlock() do {} while (0)
769 
dpm_suspend_start(pm_message_t state)770 static inline int dpm_suspend_start(pm_message_t state)
771 {
772 	return 0;
773 }
774 
775 #define suspend_report_result(fn, ret)		do {} while (0)
776 
device_pm_wait_for_dev(struct device * a,struct device * b)777 static inline int device_pm_wait_for_dev(struct device *a, struct device *b)
778 {
779 	return 0;
780 }
781 
dpm_for_each_dev(void * data,void (* fn)(struct device *,void *))782 static inline void dpm_for_each_dev(void *data, void (*fn)(struct device *, void *))
783 {
784 }
785 
786 #define pm_generic_prepare		NULL
787 #define pm_generic_suspend_late		NULL
788 #define pm_generic_suspend_noirq	NULL
789 #define pm_generic_suspend		NULL
790 #define pm_generic_resume_early		NULL
791 #define pm_generic_resume_noirq		NULL
792 #define pm_generic_resume		NULL
793 #define pm_generic_freeze_noirq		NULL
794 #define pm_generic_freeze_late		NULL
795 #define pm_generic_freeze		NULL
796 #define pm_generic_thaw_noirq		NULL
797 #define pm_generic_thaw_early		NULL
798 #define pm_generic_thaw			NULL
799 #define pm_generic_restore_noirq	NULL
800 #define pm_generic_restore_early	NULL
801 #define pm_generic_restore		NULL
802 #define pm_generic_poweroff_noirq	NULL
803 #define pm_generic_poweroff_late	NULL
804 #define pm_generic_poweroff		NULL
805 #define pm_generic_complete		NULL
806 #endif /* !CONFIG_PM_SLEEP */
807 
808 /* How to reorder dpm_list after device_move() */
809 enum dpm_order {
810 	DPM_ORDER_NONE,
811 	DPM_ORDER_DEV_AFTER_PARENT,
812 	DPM_ORDER_PARENT_BEFORE_DEV,
813 	DPM_ORDER_DEV_LAST,
814 };
815 
816 #endif /* _LINUX_PM_H */
817