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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 
44 #ifdef CONFIG_PM
45 extern const char power_group_name[];		/* = "power" */
46 #else
47 #define power_group_name	NULL
48 #endif
49 
50 typedef struct pm_message {
51 	int event;
52 } pm_message_t;
53 
54 /**
55  * struct dev_pm_ops - device PM callbacks.
56  *
57  * @prepare: The principal role of this callback is to prevent new children of
58  *	the device from being registered after it has returned (the driver's
59  *	subsystem and generally the rest of the kernel is supposed to prevent
60  *	new calls to the probe method from being made too once @prepare() has
61  *	succeeded).  If @prepare() detects a situation it cannot handle (e.g.
62  *	registration of a child already in progress), it may return -EAGAIN, so
63  *	that the PM core can execute it once again (e.g. after a new child has
64  *	been registered) to recover from the race condition.
65  *	This method is executed for all kinds of suspend transitions and is
66  *	followed by one of the suspend callbacks: @suspend(), @freeze(), or
67  *	@poweroff().  If the transition is a suspend to memory or standby (that
68  *	is, not related to hibernation), the return value of @prepare() may be
69  *	used to indicate to the PM core to leave the device in runtime suspend
70  *	if applicable.  Namely, if @prepare() returns a positive number, the PM
71  *	core will understand that as a declaration that the device appears to be
72  *	runtime-suspended and it may be left in that state during the entire
73  *	transition and during the subsequent resume if all of its descendants
74  *	are left in runtime suspend too.  If that happens, @complete() will be
75  *	executed directly after @prepare() and it must ensure the proper
76  *	functioning of the device after the system resume.
77  *	The PM core executes subsystem-level @prepare() for all devices before
78  *	starting to invoke suspend callbacks for any of them, so generally
79  *	devices may be assumed to be functional or to respond to runtime resume
80  *	requests while @prepare() is being executed.  However, device drivers
81  *	may NOT assume anything about the availability of user space at that
82  *	time and it is NOT valid to request firmware from within @prepare()
83  *	(it's too late to do that).  It also is NOT valid to allocate
84  *	substantial amounts of memory from @prepare() in the GFP_KERNEL mode.
85  *	[To work around these limitations, drivers may register suspend and
86  *	hibernation notifiers to be executed before the freezing of tasks.]
87  *
88  * @complete: Undo the changes made by @prepare().  This method is executed for
89  *	all kinds of resume transitions, following one of the resume callbacks:
90  *	@resume(), @thaw(), @restore().  Also called if the state transition
91  *	fails before the driver's suspend callback: @suspend(), @freeze() or
92  *	@poweroff(), can be executed (e.g. if the suspend callback fails for one
93  *	of the other devices that the PM core has unsuccessfully attempted to
94  *	suspend earlier).
95  *	The PM core executes subsystem-level @complete() after it has executed
96  *	the appropriate resume callbacks for all devices.  If the corresponding
97  *	@prepare() at the beginning of the suspend transition returned a
98  *	positive number and the device was left in runtime suspend (without
99  *	executing any suspend and resume callbacks for it), @complete() will be
100  *	the only callback executed for the device during resume.  In that case,
101  *	@complete() must be prepared to do whatever is necessary to ensure the
102  *	proper functioning of the device after the system resume.  To this end,
103  *	@complete() can check the power.direct_complete flag of the device to
104  *	learn whether (unset) or not (set) the previous suspend and resume
105  *	callbacks have been executed for it.
106  *
107  * @suspend: Executed before putting the system into a sleep state in which the
108  *	contents of main memory are preserved.  The exact action to perform
109  *	depends on the device's subsystem (PM domain, device type, class or bus
110  *	type), but generally the device must be quiescent after subsystem-level
111  *	@suspend() has returned, so that it doesn't do any I/O or DMA.
112  *	Subsystem-level @suspend() is executed for all devices after invoking
113  *	subsystem-level @prepare() for all of them.
114  *
115  * @suspend_late: Continue operations started by @suspend().  For a number of
116  *	devices @suspend_late() may point to the same callback routine as the
117  *	runtime suspend callback.
118  *
119  * @resume: Executed after waking the system up from a sleep state in which the
120  *	contents of main memory were preserved.  The exact action to perform
121  *	depends on the device's subsystem, but generally the driver is expected
122  *	to start working again, responding to hardware events and software
123  *	requests (the device itself may be left in a low-power state, waiting
124  *	for a runtime resume to occur).  The state of the device at the time its
125  *	driver's @resume() callback is run depends on the platform and subsystem
126  *	the device belongs to.  On most platforms, there are no restrictions on
127  *	availability of resources like clocks during @resume().
128  *	Subsystem-level @resume() is executed for all devices after invoking
129  *	subsystem-level @resume_noirq() for all of them.
130  *
131  * @resume_early: Prepare to execute @resume().  For a number of devices
132  *	@resume_early() may point to the same callback routine as the runtime
133  *	resume callback.
134  *
135  * @freeze: Hibernation-specific, executed before creating a hibernation image.
136  *	Analogous to @suspend(), but it should not enable the device to signal
137  *	wakeup events or change its power state.  The majority of subsystems
138  *	(with the notable exception of the PCI bus type) expect the driver-level
139  *	@freeze() to save the device settings in memory to be used by @restore()
140  *	during the subsequent resume from hibernation.
141  *	Subsystem-level @freeze() is executed for all devices after invoking
142  *	subsystem-level @prepare() for all of them.
143  *
144  * @freeze_late: Continue operations started by @freeze().  Analogous to
145  *	@suspend_late(), but it should not enable the device to signal wakeup
146  *	events or change its power state.
147  *
148  * @thaw: Hibernation-specific, executed after creating a hibernation image OR
149  *	if the creation of an image has failed.  Also executed after a failing
150  *	attempt to restore the contents of main memory from such an image.
151  *	Undo the changes made by the preceding @freeze(), so the device can be
152  *	operated in the same way as immediately before the call to @freeze().
153  *	Subsystem-level @thaw() is executed for all devices after invoking
154  *	subsystem-level @thaw_noirq() for all of them.  It also may be executed
155  *	directly after @freeze() in case of a transition error.
156  *
157  * @thaw_early: Prepare to execute @thaw().  Undo the changes made by the
158  *	preceding @freeze_late().
159  *
160  * @poweroff: Hibernation-specific, executed after saving a hibernation image.
161  *	Analogous to @suspend(), but it need not save the device's settings in
162  *	memory.
163  *	Subsystem-level @poweroff() is executed for all devices after invoking
164  *	subsystem-level @prepare() for all of them.
165  *
166  * @poweroff_late: Continue operations started by @poweroff().  Analogous to
167  *	@suspend_late(), but it need not save the device's settings in memory.
168  *
169  * @restore: Hibernation-specific, executed after restoring the contents of main
170  *	memory from a hibernation image, analogous to @resume().
171  *
172  * @restore_early: Prepare to execute @restore(), analogous to @resume_early().
173  *
174  * @suspend_noirq: Complete the actions started by @suspend().  Carry out any
175  *	additional operations required for suspending the device that might be
176  *	racing with its driver's interrupt handler, which is guaranteed not to
177  *	run while @suspend_noirq() is being executed.
178  *	It generally is expected that the device will be in a low-power state
179  *	(appropriate for the target system sleep state) after subsystem-level
180  *	@suspend_noirq() has returned successfully.  If the device can generate
181  *	system wakeup signals and is enabled to wake up the system, it should be
182  *	configured to do so at that time.  However, depending on the platform
183  *	and device's subsystem, @suspend() or @suspend_late() may be allowed to
184  *	put the device into the low-power state and configure it to generate
185  *	wakeup signals, in which case it generally is not necessary to define
186  *	@suspend_noirq().
187  *
188  * @resume_noirq: Prepare for the execution of @resume() by carrying out any
189  *	operations required for resuming the device that might be racing with
190  *	its driver's interrupt handler, which is guaranteed not to run while
191  *	@resume_noirq() is being executed.
192  *
193  * @freeze_noirq: Complete the actions started by @freeze().  Carry out any
194  *	additional operations required for freezing the device that might be
195  *	racing with its driver's interrupt handler, which is guaranteed not to
196  *	run while @freeze_noirq() is being executed.
197  *	The power state of the device should not be changed by either @freeze(),
198  *	or @freeze_late(), or @freeze_noirq() and it should not be configured to
199  *	signal system wakeup by any of these callbacks.
200  *
201  * @thaw_noirq: Prepare for the execution of @thaw() by carrying out any
202  *	operations required for thawing the device that might be racing with its
203  *	driver's interrupt handler, which is guaranteed not to run while
204  *	@thaw_noirq() is being executed.
205  *
206  * @poweroff_noirq: Complete the actions started by @poweroff().  Analogous to
207  *	@suspend_noirq(), but it need not save the device's settings in memory.
208  *
209  * @restore_noirq: Prepare for the execution of @restore() by carrying out any
210  *	operations required for thawing the device that might be racing with its
211  *	driver's interrupt handler, which is guaranteed not to run while
212  *	@restore_noirq() is being executed.  Analogous to @resume_noirq().
213  *
214  * @runtime_suspend: Prepare the device for a condition in which it won't be
215  *	able to communicate with the CPU(s) and RAM due to power management.
216  *	This need not mean that the device should be put into a low-power state.
217  *	For example, if the device is behind a link which is about to be turned
218  *	off, the device may remain at full power.  If the device does go to low
219  *	power and is capable of generating runtime wakeup events, remote wakeup
220  *	(i.e., a hardware mechanism allowing the device to request a change of
221  *	its power state via an interrupt) should be enabled for it.
222  *
223  * @runtime_resume: Put the device into the fully active state in response to a
224  *	wakeup event generated by hardware or at the request of software.  If
225  *	necessary, put the device into the full-power state and restore its
226  *	registers, so that it is fully operational.
227  *
228  * @runtime_idle: Device appears to be inactive and it might be put into a
229  *	low-power state if all of the necessary conditions are satisfied.
230  *	Check these conditions, and return 0 if it's appropriate to let the PM
231  *	core queue a suspend request for the device.
232  *
233  * Several device power state transitions are externally visible, affecting
234  * the state of pending I/O queues and (for drivers that touch hardware)
235  * interrupts, wakeups, DMA, and other hardware state.  There may also be
236  * internal transitions to various low-power modes which are transparent
237  * to the rest of the driver stack (such as a driver that's ON gating off
238  * clocks which are not in active use).
239  *
240  * The externally visible transitions are handled with the help of callbacks
241  * included in this structure in such a way that, typically, two levels of
242  * callbacks are involved.  First, the PM core executes callbacks provided by PM
243  * domains, device types, classes and bus types.  They are the subsystem-level
244  * callbacks expected to execute callbacks provided by device drivers, although
245  * they may choose not to do that.  If the driver callbacks are executed, they
246  * have to collaborate with the subsystem-level callbacks to achieve the goals
247  * appropriate for the given system transition, given transition phase and the
248  * subsystem the device belongs to.
249  *
250  * All of the above callbacks, except for @complete(), return error codes.
251  * However, the error codes returned by @resume(), @thaw(), @restore(),
252  * @resume_noirq(), @thaw_noirq(), and @restore_noirq(), do not cause the PM
253  * core to abort the resume transition during which they are returned.  The
254  * error codes returned in those cases are only printed to the system logs for
255  * debugging purposes.  Still, it is recommended that drivers only return error
256  * codes from their resume methods in case of an unrecoverable failure (i.e.
257  * when the device being handled refuses to resume and becomes unusable) to
258  * allow the PM core to be modified in the future, so that it can avoid
259  * attempting to handle devices that failed to resume and their children.
260  *
261  * It is allowed to unregister devices while the above callbacks are being
262  * executed.  However, a callback routine MUST NOT try to unregister the device
263  * it was called for, although it may unregister children of that device (for
264  * example, if it detects that a child was unplugged while the system was
265  * asleep).
266  *
267  * There also are callbacks related to runtime power management of devices.
268  * Again, as a rule these callbacks are executed by the PM core for subsystems
269  * (PM domains, device types, classes and bus types) and the subsystem-level
270  * callbacks are expected to invoke the driver callbacks.  Moreover, the exact
271  * actions to be performed by a device driver's callbacks generally depend on
272  * the platform and subsystem the device belongs to.
273  *
274  * Refer to Documentation/power/runtime_pm.rst for more information about the
275  * role of the @runtime_suspend(), @runtime_resume() and @runtime_idle()
276  * callbacks in device runtime power management.
277  */
278 struct dev_pm_ops {
279 	int (*prepare)(struct device *dev);
280 	void (*complete)(struct device *dev);
281 	int (*suspend)(struct device *dev);
282 	int (*resume)(struct device *dev);
283 	int (*freeze)(struct device *dev);
284 	int (*thaw)(struct device *dev);
285 	int (*poweroff)(struct device *dev);
286 	int (*restore)(struct device *dev);
287 	int (*suspend_late)(struct device *dev);
288 	int (*resume_early)(struct device *dev);
289 	int (*freeze_late)(struct device *dev);
290 	int (*thaw_early)(struct device *dev);
291 	int (*poweroff_late)(struct device *dev);
292 	int (*restore_early)(struct device *dev);
293 	int (*suspend_noirq)(struct device *dev);
294 	int (*resume_noirq)(struct device *dev);
295 	int (*freeze_noirq)(struct device *dev);
296 	int (*thaw_noirq)(struct device *dev);
297 	int (*poweroff_noirq)(struct device *dev);
298 	int (*restore_noirq)(struct device *dev);
299 	int (*runtime_suspend)(struct device *dev);
300 	int (*runtime_resume)(struct device *dev);
301 	int (*runtime_idle)(struct device *dev);
302 
303 	ANDROID_KABI_RESERVE(1);
304 };
305 
306 #ifdef CONFIG_PM_SLEEP
307 #define SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
308 	.suspend = suspend_fn, \
309 	.resume = resume_fn, \
310 	.freeze = suspend_fn, \
311 	.thaw = resume_fn, \
312 	.poweroff = suspend_fn, \
313 	.restore = resume_fn,
314 #else
315 #define SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn)
316 #endif
317 
318 #ifdef CONFIG_PM_SLEEP
319 #define SET_LATE_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
320 	.suspend_late = suspend_fn, \
321 	.resume_early = resume_fn, \
322 	.freeze_late = suspend_fn, \
323 	.thaw_early = resume_fn, \
324 	.poweroff_late = suspend_fn, \
325 	.restore_early = resume_fn,
326 #else
327 #define SET_LATE_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn)
328 #endif
329 
330 #ifdef CONFIG_PM_SLEEP
331 #define SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
332 	.suspend_noirq = suspend_fn, \
333 	.resume_noirq = resume_fn, \
334 	.freeze_noirq = suspend_fn, \
335 	.thaw_noirq = resume_fn, \
336 	.poweroff_noirq = suspend_fn, \
337 	.restore_noirq = resume_fn,
338 #else
339 #define SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn)
340 #endif
341 
342 #ifdef CONFIG_PM
343 #define SET_RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn) \
344 	.runtime_suspend = suspend_fn, \
345 	.runtime_resume = resume_fn, \
346 	.runtime_idle = idle_fn,
347 #else
348 #define SET_RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn)
349 #endif
350 
351 /*
352  * Use this if you want to use the same suspend and resume callbacks for suspend
353  * to RAM and hibernation.
354  */
355 #define SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn) \
356 const struct dev_pm_ops __maybe_unused name = { \
357 	SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
358 }
359 
360 /*
361  * Use this for defining a set of PM operations to be used in all situations
362  * (system suspend, hibernation or runtime PM).
363  * NOTE: In general, system suspend callbacks, .suspend() and .resume(), should
364  * be different from the corresponding runtime PM callbacks, .runtime_suspend(),
365  * and .runtime_resume(), because .runtime_suspend() always works on an already
366  * quiescent device, while .suspend() should assume that the device may be doing
367  * something when it is called (it should ensure that the device will be
368  * quiescent after it has returned).  Therefore it's better to point the "late"
369  * suspend and "early" resume callback pointers, .suspend_late() and
370  * .resume_early(), to the same routines as .runtime_suspend() and
371  * .runtime_resume(), respectively (and analogously for hibernation).
372  */
373 #define UNIVERSAL_DEV_PM_OPS(name, suspend_fn, resume_fn, idle_fn) \
374 const struct dev_pm_ops __maybe_unused name = { \
375 	SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
376 	SET_RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn) \
377 }
378 
379 #ifdef CONFIG_PM
380 #define pm_ptr(_ptr) (_ptr)
381 #else
382 #define pm_ptr(_ptr) NULL
383 #endif
384 
385 /*
386  * PM_EVENT_ messages
387  *
388  * The following PM_EVENT_ messages are defined for the internal use of the PM
389  * core, in order to provide a mechanism allowing the high level suspend and
390  * hibernation code to convey the necessary information to the device PM core
391  * code:
392  *
393  * ON		No transition.
394  *
395  * FREEZE	System is going to hibernate, call ->prepare() and ->freeze()
396  *		for all devices.
397  *
398  * SUSPEND	System is going to suspend, call ->prepare() and ->suspend()
399  *		for all devices.
400  *
401  * HIBERNATE	Hibernation image has been saved, call ->prepare() and
402  *		->poweroff() for all devices.
403  *
404  * QUIESCE	Contents of main memory are going to be restored from a (loaded)
405  *		hibernation image, call ->prepare() and ->freeze() for all
406  *		devices.
407  *
408  * RESUME	System is resuming, call ->resume() and ->complete() for all
409  *		devices.
410  *
411  * THAW		Hibernation image has been created, call ->thaw() and
412  *		->complete() for all devices.
413  *
414  * RESTORE	Contents of main memory have been restored from a hibernation
415  *		image, call ->restore() and ->complete() for all devices.
416  *
417  * RECOVER	Creation of a hibernation image or restoration of the main
418  *		memory contents from a hibernation image has failed, call
419  *		->thaw() and ->complete() for all devices.
420  *
421  * The following PM_EVENT_ messages are defined for internal use by
422  * kernel subsystems.  They are never issued by the PM core.
423  *
424  * USER_SUSPEND		Manual selective suspend was issued by userspace.
425  *
426  * USER_RESUME		Manual selective resume was issued by userspace.
427  *
428  * REMOTE_WAKEUP	Remote-wakeup request was received from the device.
429  *
430  * AUTO_SUSPEND		Automatic (device idle) runtime suspend was
431  *			initiated by the subsystem.
432  *
433  * AUTO_RESUME		Automatic (device needed) runtime resume was
434  *			requested by a driver.
435  */
436 
437 #define PM_EVENT_INVALID	(-1)
438 #define PM_EVENT_ON		0x0000
439 #define PM_EVENT_FREEZE		0x0001
440 #define PM_EVENT_SUSPEND	0x0002
441 #define PM_EVENT_HIBERNATE	0x0004
442 #define PM_EVENT_QUIESCE	0x0008
443 #define PM_EVENT_RESUME		0x0010
444 #define PM_EVENT_THAW		0x0020
445 #define PM_EVENT_RESTORE	0x0040
446 #define PM_EVENT_RECOVER	0x0080
447 #define PM_EVENT_USER		0x0100
448 #define PM_EVENT_REMOTE		0x0200
449 #define PM_EVENT_AUTO		0x0400
450 
451 #define PM_EVENT_SLEEP		(PM_EVENT_SUSPEND | PM_EVENT_HIBERNATE)
452 #define PM_EVENT_USER_SUSPEND	(PM_EVENT_USER | PM_EVENT_SUSPEND)
453 #define PM_EVENT_USER_RESUME	(PM_EVENT_USER | PM_EVENT_RESUME)
454 #define PM_EVENT_REMOTE_RESUME	(PM_EVENT_REMOTE | PM_EVENT_RESUME)
455 #define PM_EVENT_AUTO_SUSPEND	(PM_EVENT_AUTO | PM_EVENT_SUSPEND)
456 #define PM_EVENT_AUTO_RESUME	(PM_EVENT_AUTO | PM_EVENT_RESUME)
457 
458 #define PMSG_INVALID	((struct pm_message){ .event = PM_EVENT_INVALID, })
459 #define PMSG_ON		((struct pm_message){ .event = PM_EVENT_ON, })
460 #define PMSG_FREEZE	((struct pm_message){ .event = PM_EVENT_FREEZE, })
461 #define PMSG_QUIESCE	((struct pm_message){ .event = PM_EVENT_QUIESCE, })
462 #define PMSG_SUSPEND	((struct pm_message){ .event = PM_EVENT_SUSPEND, })
463 #define PMSG_HIBERNATE	((struct pm_message){ .event = PM_EVENT_HIBERNATE, })
464 #define PMSG_RESUME	((struct pm_message){ .event = PM_EVENT_RESUME, })
465 #define PMSG_THAW	((struct pm_message){ .event = PM_EVENT_THAW, })
466 #define PMSG_RESTORE	((struct pm_message){ .event = PM_EVENT_RESTORE, })
467 #define PMSG_RECOVER	((struct pm_message){ .event = PM_EVENT_RECOVER, })
468 #define PMSG_USER_SUSPEND	((struct pm_message) \
469 					{ .event = PM_EVENT_USER_SUSPEND, })
470 #define PMSG_USER_RESUME	((struct pm_message) \
471 					{ .event = PM_EVENT_USER_RESUME, })
472 #define PMSG_REMOTE_RESUME	((struct pm_message) \
473 					{ .event = PM_EVENT_REMOTE_RESUME, })
474 #define PMSG_AUTO_SUSPEND	((struct pm_message) \
475 					{ .event = PM_EVENT_AUTO_SUSPEND, })
476 #define PMSG_AUTO_RESUME	((struct pm_message) \
477 					{ .event = PM_EVENT_AUTO_RESUME, })
478 
479 #define PMSG_IS_AUTO(msg)	(((msg).event & PM_EVENT_AUTO) != 0)
480 
481 /*
482  * Device run-time power management status.
483  *
484  * These status labels are used internally by the PM core to indicate the
485  * current status of a device with respect to the PM core operations.  They do
486  * not reflect the actual power state of the device or its status as seen by the
487  * driver.
488  *
489  * RPM_ACTIVE		Device is fully operational.  Indicates that the device
490  *			bus type's ->runtime_resume() callback has completed
491  *			successfully.
492  *
493  * RPM_SUSPENDED	Device bus type's ->runtime_suspend() callback has
494  *			completed successfully.  The device is regarded as
495  *			suspended.
496  *
497  * RPM_RESUMING		Device bus type's ->runtime_resume() callback is being
498  *			executed.
499  *
500  * RPM_SUSPENDING	Device bus type's ->runtime_suspend() callback is being
501  *			executed.
502  */
503 
504 enum rpm_status {
505 	RPM_ACTIVE = 0,
506 	RPM_RESUMING,
507 	RPM_SUSPENDED,
508 	RPM_SUSPENDING,
509 };
510 
511 /*
512  * Device run-time power management request types.
513  *
514  * RPM_REQ_NONE		Do nothing.
515  *
516  * RPM_REQ_IDLE		Run the device bus type's ->runtime_idle() callback
517  *
518  * RPM_REQ_SUSPEND	Run the device bus type's ->runtime_suspend() callback
519  *
520  * RPM_REQ_AUTOSUSPEND	Same as RPM_REQ_SUSPEND, but not until the device has
521  *			been inactive for as long as power.autosuspend_delay
522  *
523  * RPM_REQ_RESUME	Run the device bus type's ->runtime_resume() callback
524  */
525 
526 enum rpm_request {
527 	RPM_REQ_NONE = 0,
528 	RPM_REQ_IDLE,
529 	RPM_REQ_SUSPEND,
530 	RPM_REQ_AUTOSUSPEND,
531 	RPM_REQ_RESUME,
532 };
533 
534 struct wakeup_source;
535 struct wake_irq;
536 struct pm_domain_data;
537 
538 struct pm_subsys_data {
539 	spinlock_t lock;
540 	unsigned int refcount;
541 #ifdef CONFIG_PM_CLK
542 	unsigned int clock_op_might_sleep;
543 	struct mutex clock_mutex;
544 	struct list_head clock_list;
545 #endif
546 #ifdef CONFIG_PM_GENERIC_DOMAINS
547 	struct pm_domain_data *domain_data;
548 #endif
549 };
550 
551 /*
552  * Driver flags to control system suspend/resume behavior.
553  *
554  * These flags can be set by device drivers at the probe time.  They need not be
555  * cleared by the drivers as the driver core will take care of that.
556  *
557  * NO_DIRECT_COMPLETE: Do not apply direct-complete optimization to the device.
558  * SMART_PREPARE: Take the driver ->prepare callback return value into account.
559  * SMART_SUSPEND: Avoid resuming the device from runtime suspend.
560  * MAY_SKIP_RESUME: Allow driver "noirq" and "early" callbacks to be skipped.
561  *
562  * See Documentation/driver-api/pm/devices.rst for details.
563  */
564 #define DPM_FLAG_NO_DIRECT_COMPLETE	BIT(0)
565 #define DPM_FLAG_SMART_PREPARE		BIT(1)
566 #define DPM_FLAG_SMART_SUSPEND		BIT(2)
567 #define DPM_FLAG_MAY_SKIP_RESUME	BIT(3)
568 
569 struct dev_pm_info {
570 	pm_message_t		power_state;
571 	unsigned int		can_wakeup:1;
572 	unsigned int		async_suspend:1;
573 	bool			in_dpm_list:1;	/* Owned by the PM core */
574 	bool			is_prepared:1;	/* Owned by the PM core */
575 	bool			is_suspended:1;	/* Ditto */
576 	bool			is_noirq_suspended:1;
577 	bool			is_late_suspended:1;
578 	bool			no_pm:1;
579 	bool			early_init:1;	/* Owned by the PM core */
580 	bool			direct_complete:1;	/* Owned by the PM core */
581 	u32			driver_flags;
582 	spinlock_t		lock;
583 #ifdef CONFIG_PM_SLEEP
584 	struct list_head	entry;
585 	struct completion	completion;
586 	struct wakeup_source	*wakeup;
587 	bool			wakeup_path:1;
588 	bool			syscore:1;
589 	bool			no_pm_callbacks:1;	/* Owned by the PM core */
590 	unsigned int		must_resume:1;	/* Owned by the PM core */
591 	unsigned int		may_skip_resume:1;	/* Set by subsystems */
592 #else
593 	unsigned int		should_wakeup:1;
594 #endif
595 #ifdef CONFIG_PM
596 	struct hrtimer		suspend_timer;
597 	u64			timer_expires;
598 	struct work_struct	work;
599 	wait_queue_head_t	wait_queue;
600 	struct wake_irq		*wakeirq;
601 	atomic_t		usage_count;
602 	atomic_t		child_count;
603 	unsigned int		disable_depth:3;
604 	unsigned int		idle_notification:1;
605 	unsigned int		request_pending:1;
606 	unsigned int		deferred_resume:1;
607 	unsigned int		needs_force_resume:1;
608 	unsigned int		runtime_auto:1;
609 	bool			ignore_children:1;
610 	unsigned int		no_callbacks:1;
611 	unsigned int		irq_safe:1;
612 	unsigned int		use_autosuspend:1;
613 	unsigned int		timer_autosuspends:1;
614 	unsigned int		memalloc_noio:1;
615 	unsigned int		links_count;
616 	enum rpm_request	request;
617 	enum rpm_status		runtime_status;
618 	int			runtime_error;
619 	int			autosuspend_delay;
620 	u64			last_busy;
621 	u64			active_time;
622 	u64			suspended_time;
623 	u64			accounting_timestamp;
624 #endif
625 	struct pm_subsys_data	*subsys_data;  /* Owned by the subsystem. */
626 	void (*set_latency_tolerance)(struct device *, s32);
627 	struct dev_pm_qos	*qos;
628 
629 	ANDROID_KABI_RESERVE(1);
630 	ANDROID_KABI_RESERVE(2);
631 };
632 
633 extern int dev_pm_get_subsys_data(struct device *dev);
634 extern void dev_pm_put_subsys_data(struct device *dev);
635 
636 /**
637  * struct dev_pm_domain - power management domain representation.
638  *
639  * @ops: Power management operations associated with this domain.
640  * @start: Called when a user needs to start the device via the domain.
641  * @detach: Called when removing a device from the domain.
642  * @activate: Called before executing probe routines for bus types and drivers.
643  * @sync: Called after successful driver probe.
644  * @dismiss: Called after unsuccessful driver probe and after driver removal.
645  *
646  * Power domains provide callbacks that are executed during system suspend,
647  * hibernation, system resume and during runtime PM transitions instead of
648  * subsystem-level and driver-level callbacks.
649  */
650 struct dev_pm_domain {
651 	struct dev_pm_ops	ops;
652 	int (*start)(struct device *dev);
653 	void (*detach)(struct device *dev, bool power_off);
654 	int (*activate)(struct device *dev);
655 	void (*sync)(struct device *dev);
656 	void (*dismiss)(struct device *dev);
657 
658 	ANDROID_KABI_RESERVE(1);
659 };
660 
661 /*
662  * The PM_EVENT_ messages are also used by drivers implementing the legacy
663  * suspend framework, based on the ->suspend() and ->resume() callbacks common
664  * for suspend and hibernation transitions, according to the rules below.
665  */
666 
667 /* Necessary, because several drivers use PM_EVENT_PRETHAW */
668 #define PM_EVENT_PRETHAW PM_EVENT_QUIESCE
669 
670 /*
671  * One transition is triggered by resume(), after a suspend() call; the
672  * message is implicit:
673  *
674  * ON		Driver starts working again, responding to hardware events
675  *		and software requests.  The hardware may have gone through
676  *		a power-off reset, or it may have maintained state from the
677  *		previous suspend() which the driver will rely on while
678  *		resuming.  On most platforms, there are no restrictions on
679  *		availability of resources like clocks during resume().
680  *
681  * Other transitions are triggered by messages sent using suspend().  All
682  * these transitions quiesce the driver, so that I/O queues are inactive.
683  * That commonly entails turning off IRQs and DMA; there may be rules
684  * about how to quiesce that are specific to the bus or the device's type.
685  * (For example, network drivers mark the link state.)  Other details may
686  * differ according to the message:
687  *
688  * SUSPEND	Quiesce, enter a low power device state appropriate for
689  *		the upcoming system state (such as PCI_D3hot), and enable
690  *		wakeup events as appropriate.
691  *
692  * HIBERNATE	Enter a low power device state appropriate for the hibernation
693  *		state (eg. ACPI S4) and enable wakeup events as appropriate.
694  *
695  * FREEZE	Quiesce operations so that a consistent image can be saved;
696  *		but do NOT otherwise enter a low power device state, and do
697  *		NOT emit system wakeup events.
698  *
699  * PRETHAW	Quiesce as if for FREEZE; additionally, prepare for restoring
700  *		the system from a snapshot taken after an earlier FREEZE.
701  *		Some drivers will need to reset their hardware state instead
702  *		of preserving it, to ensure that it's never mistaken for the
703  *		state which that earlier snapshot had set up.
704  *
705  * A minimally power-aware driver treats all messages as SUSPEND, fully
706  * reinitializes its device during resume() -- whether or not it was reset
707  * during the suspend/resume cycle -- and can't issue wakeup events.
708  *
709  * More power-aware drivers may also use low power states at runtime as
710  * well as during system sleep states like PM_SUSPEND_STANDBY.  They may
711  * be able to use wakeup events to exit from runtime low-power states,
712  * or from system low-power states such as standby or suspend-to-RAM.
713  */
714 
715 #ifdef CONFIG_PM_SLEEP
716 extern void device_pm_lock(void);
717 extern void dpm_resume_start(pm_message_t state);
718 extern void dpm_resume_end(pm_message_t state);
719 extern void dpm_resume_noirq(pm_message_t state);
720 extern void dpm_resume_early(pm_message_t state);
721 extern void dpm_resume(pm_message_t state);
722 extern void dpm_complete(pm_message_t state);
723 
724 extern void device_pm_unlock(void);
725 extern int dpm_suspend_end(pm_message_t state);
726 extern int dpm_suspend_start(pm_message_t state);
727 extern int dpm_suspend_noirq(pm_message_t state);
728 extern int dpm_suspend_late(pm_message_t state);
729 extern int dpm_suspend(pm_message_t state);
730 extern int dpm_prepare(pm_message_t state);
731 
732 extern void __suspend_report_result(const char *function, void *fn, int ret);
733 
734 #define suspend_report_result(fn, ret)					\
735 	do {								\
736 		__suspend_report_result(__func__, fn, ret);		\
737 	} while (0)
738 
739 extern int device_pm_wait_for_dev(struct device *sub, struct device *dev);
740 extern void dpm_for_each_dev(void *data, void (*fn)(struct device *, void *));
741 
742 extern int pm_generic_prepare(struct device *dev);
743 extern int pm_generic_suspend_late(struct device *dev);
744 extern int pm_generic_suspend_noirq(struct device *dev);
745 extern int pm_generic_suspend(struct device *dev);
746 extern int pm_generic_resume_early(struct device *dev);
747 extern int pm_generic_resume_noirq(struct device *dev);
748 extern int pm_generic_resume(struct device *dev);
749 extern int pm_generic_freeze_noirq(struct device *dev);
750 extern int pm_generic_freeze_late(struct device *dev);
751 extern int pm_generic_freeze(struct device *dev);
752 extern int pm_generic_thaw_noirq(struct device *dev);
753 extern int pm_generic_thaw_early(struct device *dev);
754 extern int pm_generic_thaw(struct device *dev);
755 extern int pm_generic_restore_noirq(struct device *dev);
756 extern int pm_generic_restore_early(struct device *dev);
757 extern int pm_generic_restore(struct device *dev);
758 extern int pm_generic_poweroff_noirq(struct device *dev);
759 extern int pm_generic_poweroff_late(struct device *dev);
760 extern int pm_generic_poweroff(struct device *dev);
761 extern void pm_generic_complete(struct device *dev);
762 
763 extern bool dev_pm_skip_resume(struct device *dev);
764 extern bool dev_pm_skip_suspend(struct device *dev);
765 
766 #else /* !CONFIG_PM_SLEEP */
767 
768 #define device_pm_lock() do {} while (0)
769 #define device_pm_unlock() do {} while (0)
770 
dpm_suspend_start(pm_message_t state)771 static inline int dpm_suspend_start(pm_message_t state)
772 {
773 	return 0;
774 }
775 
776 #define suspend_report_result(fn, ret)		do {} while (0)
777 
device_pm_wait_for_dev(struct device * a,struct device * b)778 static inline int device_pm_wait_for_dev(struct device *a, struct device *b)
779 {
780 	return 0;
781 }
782 
dpm_for_each_dev(void * data,void (* fn)(struct device *,void *))783 static inline void dpm_for_each_dev(void *data, void (*fn)(struct device *, void *))
784 {
785 }
786 
787 #define pm_generic_prepare		NULL
788 #define pm_generic_suspend_late		NULL
789 #define pm_generic_suspend_noirq	NULL
790 #define pm_generic_suspend		NULL
791 #define pm_generic_resume_early		NULL
792 #define pm_generic_resume_noirq		NULL
793 #define pm_generic_resume		NULL
794 #define pm_generic_freeze_noirq		NULL
795 #define pm_generic_freeze_late		NULL
796 #define pm_generic_freeze		NULL
797 #define pm_generic_thaw_noirq		NULL
798 #define pm_generic_thaw_early		NULL
799 #define pm_generic_thaw			NULL
800 #define pm_generic_restore_noirq	NULL
801 #define pm_generic_restore_early	NULL
802 #define pm_generic_restore		NULL
803 #define pm_generic_poweroff_noirq	NULL
804 #define pm_generic_poweroff_late	NULL
805 #define pm_generic_poweroff		NULL
806 #define pm_generic_complete		NULL
807 #endif /* !CONFIG_PM_SLEEP */
808 
809 /* How to reorder dpm_list after device_move() */
810 enum dpm_order {
811 	DPM_ORDER_NONE,
812 	DPM_ORDER_DEV_AFTER_PARENT,
813 	DPM_ORDER_PARENT_BEFORE_DEV,
814 	DPM_ORDER_DEV_LAST,
815 };
816 
817 #endif /* _LINUX_PM_H */
818