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/export.h>
12 #include <linux/list.h>
13 #include <linux/workqueue.h>
14 #include <linux/spinlock.h>
15 #include <linux/wait.h>
16 #include <linux/timer.h>
17 #include <linux/hrtimer.h>
18 #include <linux/completion.h>
19 
20 /*
21  * Callbacks for platform drivers to implement.
22  */
23 extern void (*pm_power_off)(void);
24 
25 struct device; /* we have a circular dep with device.h */
26 #ifdef CONFIG_VT_CONSOLE_SLEEP
27 extern void pm_vt_switch_required(struct device *dev, bool required);
28 extern void pm_vt_switch_unregister(struct device *dev);
29 #else
pm_vt_switch_required(struct device * dev,bool required)30 static inline void pm_vt_switch_required(struct device *dev, bool required)
31 {
32 }
pm_vt_switch_unregister(struct device * dev)33 static inline void pm_vt_switch_unregister(struct device *dev)
34 {
35 }
36 #endif /* CONFIG_VT_CONSOLE_SLEEP */
37 
38 #ifdef CONFIG_CXL_SUSPEND
39 bool cxl_mem_active(void);
40 #else
cxl_mem_active(void)41 static inline bool cxl_mem_active(void)
42 {
43 	return false;
44 }
45 #endif
46 
47 /*
48  * Device power management
49  */
50 
51 
52 #ifdef CONFIG_PM
53 extern const char power_group_name[];		/* = "power" */
54 #else
55 #define power_group_name	NULL
56 #endif
57 
58 typedef struct pm_message {
59 	int event;
60 } pm_message_t;
61 
62 /**
63  * struct dev_pm_ops - device PM callbacks.
64  *
65  * @prepare: The principal role of this callback is to prevent new children of
66  *	the device from being registered after it has returned (the driver's
67  *	subsystem and generally the rest of the kernel is supposed to prevent
68  *	new calls to the probe method from being made too once @prepare() has
69  *	succeeded).  If @prepare() detects a situation it cannot handle (e.g.
70  *	registration of a child already in progress), it may return -EAGAIN, so
71  *	that the PM core can execute it once again (e.g. after a new child has
72  *	been registered) to recover from the race condition.
73  *	This method is executed for all kinds of suspend transitions and is
74  *	followed by one of the suspend callbacks: @suspend(), @freeze(), or
75  *	@poweroff().  If the transition is a suspend to memory or standby (that
76  *	is, not related to hibernation), the return value of @prepare() may be
77  *	used to indicate to the PM core to leave the device in runtime suspend
78  *	if applicable.  Namely, if @prepare() returns a positive number, the PM
79  *	core will understand that as a declaration that the device appears to be
80  *	runtime-suspended and it may be left in that state during the entire
81  *	transition and during the subsequent resume if all of its descendants
82  *	are left in runtime suspend too.  If that happens, @complete() will be
83  *	executed directly after @prepare() and it must ensure the proper
84  *	functioning of the device after the system resume.
85  *	The PM core executes subsystem-level @prepare() for all devices before
86  *	starting to invoke suspend callbacks for any of them, so generally
87  *	devices may be assumed to be functional or to respond to runtime resume
88  *	requests while @prepare() is being executed.  However, device drivers
89  *	may NOT assume anything about the availability of user space at that
90  *	time and it is NOT valid to request firmware from within @prepare()
91  *	(it's too late to do that).  It also is NOT valid to allocate
92  *	substantial amounts of memory from @prepare() in the GFP_KERNEL mode.
93  *	[To work around these limitations, drivers may register suspend and
94  *	hibernation notifiers to be executed before the freezing of tasks.]
95  *
96  * @complete: Undo the changes made by @prepare().  This method is executed for
97  *	all kinds of resume transitions, following one of the resume callbacks:
98  *	@resume(), @thaw(), @restore().  Also called if the state transition
99  *	fails before the driver's suspend callback: @suspend(), @freeze() or
100  *	@poweroff(), can be executed (e.g. if the suspend callback fails for one
101  *	of the other devices that the PM core has unsuccessfully attempted to
102  *	suspend earlier).
103  *	The PM core executes subsystem-level @complete() after it has executed
104  *	the appropriate resume callbacks for all devices.  If the corresponding
105  *	@prepare() at the beginning of the suspend transition returned a
106  *	positive number and the device was left in runtime suspend (without
107  *	executing any suspend and resume callbacks for it), @complete() will be
108  *	the only callback executed for the device during resume.  In that case,
109  *	@complete() must be prepared to do whatever is necessary to ensure the
110  *	proper functioning of the device after the system resume.  To this end,
111  *	@complete() can check the power.direct_complete flag of the device to
112  *	learn whether (unset) or not (set) the previous suspend and resume
113  *	callbacks have been executed for it.
114  *
115  * @suspend: Executed before putting the system into a sleep state in which the
116  *	contents of main memory are preserved.  The exact action to perform
117  *	depends on the device's subsystem (PM domain, device type, class or bus
118  *	type), but generally the device must be quiescent after subsystem-level
119  *	@suspend() has returned, so that it doesn't do any I/O or DMA.
120  *	Subsystem-level @suspend() is executed for all devices after invoking
121  *	subsystem-level @prepare() for all of them.
122  *
123  * @suspend_late: Continue operations started by @suspend().  For a number of
124  *	devices @suspend_late() may point to the same callback routine as the
125  *	runtime suspend callback.
126  *
127  * @resume: Executed after waking the system up from a sleep state in which the
128  *	contents of main memory were preserved.  The exact action to perform
129  *	depends on the device's subsystem, but generally the driver is expected
130  *	to start working again, responding to hardware events and software
131  *	requests (the device itself may be left in a low-power state, waiting
132  *	for a runtime resume to occur).  The state of the device at the time its
133  *	driver's @resume() callback is run depends on the platform and subsystem
134  *	the device belongs to.  On most platforms, there are no restrictions on
135  *	availability of resources like clocks during @resume().
136  *	Subsystem-level @resume() is executed for all devices after invoking
137  *	subsystem-level @resume_noirq() for all of them.
138  *
139  * @resume_early: Prepare to execute @resume().  For a number of devices
140  *	@resume_early() may point to the same callback routine as the runtime
141  *	resume callback.
142  *
143  * @freeze: Hibernation-specific, executed before creating a hibernation image.
144  *	Analogous to @suspend(), but it should not enable the device to signal
145  *	wakeup events or change its power state.  The majority of subsystems
146  *	(with the notable exception of the PCI bus type) expect the driver-level
147  *	@freeze() to save the device settings in memory to be used by @restore()
148  *	during the subsequent resume from hibernation.
149  *	Subsystem-level @freeze() is executed for all devices after invoking
150  *	subsystem-level @prepare() for all of them.
151  *
152  * @freeze_late: Continue operations started by @freeze().  Analogous to
153  *	@suspend_late(), but it should not enable the device to signal wakeup
154  *	events or change its power state.
155  *
156  * @thaw: Hibernation-specific, executed after creating a hibernation image OR
157  *	if the creation of an image has failed.  Also executed after a failing
158  *	attempt to restore the contents of main memory from such an image.
159  *	Undo the changes made by the preceding @freeze(), so the device can be
160  *	operated in the same way as immediately before the call to @freeze().
161  *	Subsystem-level @thaw() is executed for all devices after invoking
162  *	subsystem-level @thaw_noirq() for all of them.  It also may be executed
163  *	directly after @freeze() in case of a transition error.
164  *
165  * @thaw_early: Prepare to execute @thaw().  Undo the changes made by the
166  *	preceding @freeze_late().
167  *
168  * @poweroff: Hibernation-specific, executed after saving a hibernation image.
169  *	Analogous to @suspend(), but it need not save the device's settings in
170  *	memory.
171  *	Subsystem-level @poweroff() is executed for all devices after invoking
172  *	subsystem-level @prepare() for all of them.
173  *
174  * @poweroff_late: Continue operations started by @poweroff().  Analogous to
175  *	@suspend_late(), but it need not save the device's settings in memory.
176  *
177  * @restore: Hibernation-specific, executed after restoring the contents of main
178  *	memory from a hibernation image, analogous to @resume().
179  *
180  * @restore_early: Prepare to execute @restore(), analogous to @resume_early().
181  *
182  * @suspend_noirq: Complete the actions started by @suspend().  Carry out any
183  *	additional operations required for suspending the device that might be
184  *	racing with its driver's interrupt handler, which is guaranteed not to
185  *	run while @suspend_noirq() is being executed.
186  *	It generally is expected that the device will be in a low-power state
187  *	(appropriate for the target system sleep state) after subsystem-level
188  *	@suspend_noirq() has returned successfully.  If the device can generate
189  *	system wakeup signals and is enabled to wake up the system, it should be
190  *	configured to do so at that time.  However, depending on the platform
191  *	and device's subsystem, @suspend() or @suspend_late() may be allowed to
192  *	put the device into the low-power state and configure it to generate
193  *	wakeup signals, in which case it generally is not necessary to define
194  *	@suspend_noirq().
195  *
196  * @resume_noirq: Prepare for the execution of @resume() by carrying out any
197  *	operations required for resuming the device that might be racing with
198  *	its driver's interrupt handler, which is guaranteed not to run while
199  *	@resume_noirq() is being executed.
200  *
201  * @freeze_noirq: Complete the actions started by @freeze().  Carry out any
202  *	additional operations required for freezing the device that might be
203  *	racing with its driver's interrupt handler, which is guaranteed not to
204  *	run while @freeze_noirq() is being executed.
205  *	The power state of the device should not be changed by either @freeze(),
206  *	or @freeze_late(), or @freeze_noirq() and it should not be configured to
207  *	signal system wakeup by any of these callbacks.
208  *
209  * @thaw_noirq: Prepare for the execution of @thaw() 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  *	@thaw_noirq() is being executed.
213  *
214  * @poweroff_noirq: Complete the actions started by @poweroff().  Analogous to
215  *	@suspend_noirq(), but it need not save the device's settings in memory.
216  *
217  * @restore_noirq: Prepare for the execution of @restore() by carrying out any
218  *	operations required for thawing the device that might be racing with its
219  *	driver's interrupt handler, which is guaranteed not to run while
220  *	@restore_noirq() is being executed.  Analogous to @resume_noirq().
221  *
222  * @runtime_suspend: Prepare the device for a condition in which it won't be
223  *	able to communicate with the CPU(s) and RAM due to power management.
224  *	This need not mean that the device should be put into a low-power state.
225  *	For example, if the device is behind a link which is about to be turned
226  *	off, the device may remain at full power.  If the device does go to low
227  *	power and is capable of generating runtime wakeup events, remote wakeup
228  *	(i.e., a hardware mechanism allowing the device to request a change of
229  *	its power state via an interrupt) should be enabled for it.
230  *
231  * @runtime_resume: Put the device into the fully active state in response to a
232  *	wakeup event generated by hardware or at the request of software.  If
233  *	necessary, put the device into the full-power state and restore its
234  *	registers, so that it is fully operational.
235  *
236  * @runtime_idle: Device appears to be inactive and it might be put into a
237  *	low-power state if all of the necessary conditions are satisfied.
238  *	Check these conditions, and return 0 if it's appropriate to let the PM
239  *	core queue a suspend request for the device.
240  *
241  * Several device power state transitions are externally visible, affecting
242  * the state of pending I/O queues and (for drivers that touch hardware)
243  * interrupts, wakeups, DMA, and other hardware state.  There may also be
244  * internal transitions to various low-power modes which are transparent
245  * to the rest of the driver stack (such as a driver that's ON gating off
246  * clocks which are not in active use).
247  *
248  * The externally visible transitions are handled with the help of callbacks
249  * included in this structure in such a way that, typically, two levels of
250  * callbacks are involved.  First, the PM core executes callbacks provided by PM
251  * domains, device types, classes and bus types.  They are the subsystem-level
252  * callbacks expected to execute callbacks provided by device drivers, although
253  * they may choose not to do that.  If the driver callbacks are executed, they
254  * have to collaborate with the subsystem-level callbacks to achieve the goals
255  * appropriate for the given system transition, given transition phase and the
256  * subsystem the device belongs to.
257  *
258  * All of the above callbacks, except for @complete(), return error codes.
259  * However, the error codes returned by @resume(), @thaw(), @restore(),
260  * @resume_noirq(), @thaw_noirq(), and @restore_noirq(), do not cause the PM
261  * core to abort the resume transition during which they are returned.  The
262  * error codes returned in those cases are only printed to the system logs for
263  * debugging purposes.  Still, it is recommended that drivers only return error
264  * codes from their resume methods in case of an unrecoverable failure (i.e.
265  * when the device being handled refuses to resume and becomes unusable) to
266  * allow the PM core to be modified in the future, so that it can avoid
267  * attempting to handle devices that failed to resume and their children.
268  *
269  * It is allowed to unregister devices while the above callbacks are being
270  * executed.  However, a callback routine MUST NOT try to unregister the device
271  * it was called for, although it may unregister children of that device (for
272  * example, if it detects that a child was unplugged while the system was
273  * asleep).
274  *
275  * There also are callbacks related to runtime power management of devices.
276  * Again, as a rule these callbacks are executed by the PM core for subsystems
277  * (PM domains, device types, classes and bus types) and the subsystem-level
278  * callbacks are expected to invoke the driver callbacks.  Moreover, the exact
279  * actions to be performed by a device driver's callbacks generally depend on
280  * the platform and subsystem the device belongs to.
281  *
282  * Refer to Documentation/power/runtime_pm.rst for more information about the
283  * role of the @runtime_suspend(), @runtime_resume() and @runtime_idle()
284  * callbacks in device runtime power management.
285  */
286 struct dev_pm_ops {
287 	int (*prepare)(struct device *dev);
288 	void (*complete)(struct device *dev);
289 	int (*suspend)(struct device *dev);
290 	int (*resume)(struct device *dev);
291 	int (*freeze)(struct device *dev);
292 	int (*thaw)(struct device *dev);
293 	int (*poweroff)(struct device *dev);
294 	int (*restore)(struct device *dev);
295 	int (*suspend_late)(struct device *dev);
296 	int (*resume_early)(struct device *dev);
297 	int (*freeze_late)(struct device *dev);
298 	int (*thaw_early)(struct device *dev);
299 	int (*poweroff_late)(struct device *dev);
300 	int (*restore_early)(struct device *dev);
301 	int (*suspend_noirq)(struct device *dev);
302 	int (*resume_noirq)(struct device *dev);
303 	int (*freeze_noirq)(struct device *dev);
304 	int (*thaw_noirq)(struct device *dev);
305 	int (*poweroff_noirq)(struct device *dev);
306 	int (*restore_noirq)(struct device *dev);
307 	int (*runtime_suspend)(struct device *dev);
308 	int (*runtime_resume)(struct device *dev);
309 	int (*runtime_idle)(struct device *dev);
310 };
311 
312 #define SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
313 	.suspend = pm_sleep_ptr(suspend_fn), \
314 	.resume = pm_sleep_ptr(resume_fn), \
315 	.freeze = pm_sleep_ptr(suspend_fn), \
316 	.thaw = pm_sleep_ptr(resume_fn), \
317 	.poweroff = pm_sleep_ptr(suspend_fn), \
318 	.restore = pm_sleep_ptr(resume_fn),
319 
320 #define LATE_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
321 	.suspend_late = pm_sleep_ptr(suspend_fn), \
322 	.resume_early = pm_sleep_ptr(resume_fn), \
323 	.freeze_late = pm_sleep_ptr(suspend_fn), \
324 	.thaw_early = pm_sleep_ptr(resume_fn), \
325 	.poweroff_late = pm_sleep_ptr(suspend_fn), \
326 	.restore_early = pm_sleep_ptr(resume_fn),
327 
328 #define NOIRQ_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
329 	.suspend_noirq = pm_sleep_ptr(suspend_fn), \
330 	.resume_noirq = pm_sleep_ptr(resume_fn), \
331 	.freeze_noirq = pm_sleep_ptr(suspend_fn), \
332 	.thaw_noirq = pm_sleep_ptr(resume_fn), \
333 	.poweroff_noirq = pm_sleep_ptr(suspend_fn), \
334 	.restore_noirq = pm_sleep_ptr(resume_fn),
335 
336 #define RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn) \
337 	.runtime_suspend = suspend_fn, \
338 	.runtime_resume = resume_fn, \
339 	.runtime_idle = idle_fn,
340 
341 #ifdef CONFIG_PM_SLEEP
342 #define SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
343 	SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn)
344 #else
345 #define SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn)
346 #endif
347 
348 #ifdef CONFIG_PM_SLEEP
349 #define SET_LATE_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
350 	LATE_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn)
351 #else
352 #define SET_LATE_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn)
353 #endif
354 
355 #ifdef CONFIG_PM_SLEEP
356 #define SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
357 	NOIRQ_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn)
358 #else
359 #define SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn)
360 #endif
361 
362 #ifdef CONFIG_PM
363 #define SET_RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn) \
364 	RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn)
365 #else
366 #define SET_RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn)
367 #endif
368 
369 #define _DEFINE_DEV_PM_OPS(name, \
370 			   suspend_fn, resume_fn, \
371 			   runtime_suspend_fn, runtime_resume_fn, idle_fn) \
372 const struct dev_pm_ops name = { \
373 	SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
374 	RUNTIME_PM_OPS(runtime_suspend_fn, runtime_resume_fn, idle_fn) \
375 }
376 
377 #ifdef CONFIG_PM
378 #define _EXPORT_DEV_PM_OPS(name, sec, ns)				\
379 	const struct dev_pm_ops name;					\
380 	__EXPORT_SYMBOL(name, sec, ns);					\
381 	const struct dev_pm_ops name
382 #else
383 #define _EXPORT_DEV_PM_OPS(name, sec, ns)				\
384 	static __maybe_unused const struct dev_pm_ops __static_##name
385 #endif
386 
387 #define EXPORT_DEV_PM_OPS(name) _EXPORT_DEV_PM_OPS(name, "", "")
388 #define EXPORT_GPL_DEV_PM_OPS(name) _EXPORT_DEV_PM_OPS(name, "_gpl", "")
389 #define EXPORT_NS_DEV_PM_OPS(name, ns) _EXPORT_DEV_PM_OPS(name, "", #ns)
390 #define EXPORT_NS_GPL_DEV_PM_OPS(name, ns) _EXPORT_DEV_PM_OPS(name, "_gpl", #ns)
391 
392 /*
393  * Use this if you want to use the same suspend and resume callbacks for suspend
394  * to RAM and hibernation.
395  *
396  * If the underlying dev_pm_ops struct symbol has to be exported, use
397  * EXPORT_SIMPLE_DEV_PM_OPS() or EXPORT_GPL_SIMPLE_DEV_PM_OPS() instead.
398  */
399 #define DEFINE_SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn) \
400 	_DEFINE_DEV_PM_OPS(name, suspend_fn, resume_fn, NULL, NULL, NULL)
401 
402 #define EXPORT_SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn) \
403 	EXPORT_DEV_PM_OPS(name) = { \
404 		SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
405 	}
406 #define EXPORT_GPL_SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn) \
407 	EXPORT_GPL_DEV_PM_OPS(name) = { \
408 		SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
409 	}
410 #define EXPORT_NS_SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn, ns)	\
411 	EXPORT_NS_DEV_PM_OPS(name, ns) = { \
412 		SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
413 	}
414 #define EXPORT_NS_GPL_SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn, ns)	\
415 	EXPORT_NS_GPL_DEV_PM_OPS(name, ns) = { \
416 		SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
417 	}
418 
419 /* Deprecated. Use DEFINE_SIMPLE_DEV_PM_OPS() instead. */
420 #define SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn) \
421 const struct dev_pm_ops __maybe_unused name = { \
422 	SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
423 }
424 
425 /*
426  * Use this for defining a set of PM operations to be used in all situations
427  * (system suspend, hibernation or runtime PM).
428  * NOTE: In general, system suspend callbacks, .suspend() and .resume(), should
429  * be different from the corresponding runtime PM callbacks, .runtime_suspend(),
430  * and .runtime_resume(), because .runtime_suspend() always works on an already
431  * quiescent device, while .suspend() should assume that the device may be doing
432  * something when it is called (it should ensure that the device will be
433  * quiescent after it has returned).  Therefore it's better to point the "late"
434  * suspend and "early" resume callback pointers, .suspend_late() and
435  * .resume_early(), to the same routines as .runtime_suspend() and
436  * .runtime_resume(), respectively (and analogously for hibernation).
437  *
438  * Deprecated. You most likely don't want this macro. Use
439  * DEFINE_RUNTIME_DEV_PM_OPS() instead.
440  */
441 #define UNIVERSAL_DEV_PM_OPS(name, suspend_fn, resume_fn, idle_fn) \
442 const struct dev_pm_ops __maybe_unused name = { \
443 	SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
444 	SET_RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn) \
445 }
446 
447 #define pm_ptr(_ptr) PTR_IF(IS_ENABLED(CONFIG_PM), (_ptr))
448 #define pm_sleep_ptr(_ptr) PTR_IF(IS_ENABLED(CONFIG_PM_SLEEP), (_ptr))
449 
450 /*
451  * PM_EVENT_ messages
452  *
453  * The following PM_EVENT_ messages are defined for the internal use of the PM
454  * core, in order to provide a mechanism allowing the high level suspend and
455  * hibernation code to convey the necessary information to the device PM core
456  * code:
457  *
458  * ON		No transition.
459  *
460  * FREEZE	System is going to hibernate, call ->prepare() and ->freeze()
461  *		for all devices.
462  *
463  * SUSPEND	System is going to suspend, call ->prepare() and ->suspend()
464  *		for all devices.
465  *
466  * HIBERNATE	Hibernation image has been saved, call ->prepare() and
467  *		->poweroff() for all devices.
468  *
469  * QUIESCE	Contents of main memory are going to be restored from a (loaded)
470  *		hibernation image, call ->prepare() and ->freeze() for all
471  *		devices.
472  *
473  * RESUME	System is resuming, call ->resume() and ->complete() for all
474  *		devices.
475  *
476  * THAW		Hibernation image has been created, call ->thaw() and
477  *		->complete() for all devices.
478  *
479  * RESTORE	Contents of main memory have been restored from a hibernation
480  *		image, call ->restore() and ->complete() for all devices.
481  *
482  * RECOVER	Creation of a hibernation image or restoration of the main
483  *		memory contents from a hibernation image has failed, call
484  *		->thaw() and ->complete() for all devices.
485  *
486  * The following PM_EVENT_ messages are defined for internal use by
487  * kernel subsystems.  They are never issued by the PM core.
488  *
489  * USER_SUSPEND		Manual selective suspend was issued by userspace.
490  *
491  * USER_RESUME		Manual selective resume was issued by userspace.
492  *
493  * REMOTE_WAKEUP	Remote-wakeup request was received from the device.
494  *
495  * AUTO_SUSPEND		Automatic (device idle) runtime suspend was
496  *			initiated by the subsystem.
497  *
498  * AUTO_RESUME		Automatic (device needed) runtime resume was
499  *			requested by a driver.
500  */
501 
502 #define PM_EVENT_INVALID	(-1)
503 #define PM_EVENT_ON		0x0000
504 #define PM_EVENT_FREEZE		0x0001
505 #define PM_EVENT_SUSPEND	0x0002
506 #define PM_EVENT_HIBERNATE	0x0004
507 #define PM_EVENT_QUIESCE	0x0008
508 #define PM_EVENT_RESUME		0x0010
509 #define PM_EVENT_THAW		0x0020
510 #define PM_EVENT_RESTORE	0x0040
511 #define PM_EVENT_RECOVER	0x0080
512 #define PM_EVENT_USER		0x0100
513 #define PM_EVENT_REMOTE		0x0200
514 #define PM_EVENT_AUTO		0x0400
515 
516 #define PM_EVENT_SLEEP		(PM_EVENT_SUSPEND | PM_EVENT_HIBERNATE)
517 #define PM_EVENT_USER_SUSPEND	(PM_EVENT_USER | PM_EVENT_SUSPEND)
518 #define PM_EVENT_USER_RESUME	(PM_EVENT_USER | PM_EVENT_RESUME)
519 #define PM_EVENT_REMOTE_RESUME	(PM_EVENT_REMOTE | PM_EVENT_RESUME)
520 #define PM_EVENT_AUTO_SUSPEND	(PM_EVENT_AUTO | PM_EVENT_SUSPEND)
521 #define PM_EVENT_AUTO_RESUME	(PM_EVENT_AUTO | PM_EVENT_RESUME)
522 
523 #define PMSG_INVALID	((struct pm_message){ .event = PM_EVENT_INVALID, })
524 #define PMSG_ON		((struct pm_message){ .event = PM_EVENT_ON, })
525 #define PMSG_FREEZE	((struct pm_message){ .event = PM_EVENT_FREEZE, })
526 #define PMSG_QUIESCE	((struct pm_message){ .event = PM_EVENT_QUIESCE, })
527 #define PMSG_SUSPEND	((struct pm_message){ .event = PM_EVENT_SUSPEND, })
528 #define PMSG_HIBERNATE	((struct pm_message){ .event = PM_EVENT_HIBERNATE, })
529 #define PMSG_RESUME	((struct pm_message){ .event = PM_EVENT_RESUME, })
530 #define PMSG_THAW	((struct pm_message){ .event = PM_EVENT_THAW, })
531 #define PMSG_RESTORE	((struct pm_message){ .event = PM_EVENT_RESTORE, })
532 #define PMSG_RECOVER	((struct pm_message){ .event = PM_EVENT_RECOVER, })
533 #define PMSG_USER_SUSPEND	((struct pm_message) \
534 					{ .event = PM_EVENT_USER_SUSPEND, })
535 #define PMSG_USER_RESUME	((struct pm_message) \
536 					{ .event = PM_EVENT_USER_RESUME, })
537 #define PMSG_REMOTE_RESUME	((struct pm_message) \
538 					{ .event = PM_EVENT_REMOTE_RESUME, })
539 #define PMSG_AUTO_SUSPEND	((struct pm_message) \
540 					{ .event = PM_EVENT_AUTO_SUSPEND, })
541 #define PMSG_AUTO_RESUME	((struct pm_message) \
542 					{ .event = PM_EVENT_AUTO_RESUME, })
543 
544 #define PMSG_IS_AUTO(msg)	(((msg).event & PM_EVENT_AUTO) != 0)
545 
546 /*
547  * Device run-time power management status.
548  *
549  * These status labels are used internally by the PM core to indicate the
550  * current status of a device with respect to the PM core operations.  They do
551  * not reflect the actual power state of the device or its status as seen by the
552  * driver.
553  *
554  * RPM_ACTIVE		Device is fully operational.  Indicates that the device
555  *			bus type's ->runtime_resume() callback has completed
556  *			successfully.
557  *
558  * RPM_SUSPENDED	Device bus type's ->runtime_suspend() callback has
559  *			completed successfully.  The device is regarded as
560  *			suspended.
561  *
562  * RPM_RESUMING		Device bus type's ->runtime_resume() callback is being
563  *			executed.
564  *
565  * RPM_SUSPENDING	Device bus type's ->runtime_suspend() callback is being
566  *			executed.
567  */
568 
569 enum rpm_status {
570 	RPM_INVALID = -1,
571 	RPM_ACTIVE = 0,
572 	RPM_RESUMING,
573 	RPM_SUSPENDED,
574 	RPM_SUSPENDING,
575 };
576 
577 /*
578  * Device run-time power management request types.
579  *
580  * RPM_REQ_NONE		Do nothing.
581  *
582  * RPM_REQ_IDLE		Run the device bus type's ->runtime_idle() callback
583  *
584  * RPM_REQ_SUSPEND	Run the device bus type's ->runtime_suspend() callback
585  *
586  * RPM_REQ_AUTOSUSPEND	Same as RPM_REQ_SUSPEND, but not until the device has
587  *			been inactive for as long as power.autosuspend_delay
588  *
589  * RPM_REQ_RESUME	Run the device bus type's ->runtime_resume() callback
590  */
591 
592 enum rpm_request {
593 	RPM_REQ_NONE = 0,
594 	RPM_REQ_IDLE,
595 	RPM_REQ_SUSPEND,
596 	RPM_REQ_AUTOSUSPEND,
597 	RPM_REQ_RESUME,
598 };
599 
600 struct wakeup_source;
601 struct wake_irq;
602 struct pm_domain_data;
603 
604 struct pm_subsys_data {
605 	spinlock_t lock;
606 	unsigned int refcount;
607 #ifdef CONFIG_PM_CLK
608 	unsigned int clock_op_might_sleep;
609 	struct mutex clock_mutex;
610 	struct list_head clock_list;
611 #endif
612 #ifdef CONFIG_PM_GENERIC_DOMAINS
613 	struct pm_domain_data *domain_data;
614 #endif
615 };
616 
617 /*
618  * Driver flags to control system suspend/resume behavior.
619  *
620  * These flags can be set by device drivers at the probe time.  They need not be
621  * cleared by the drivers as the driver core will take care of that.
622  *
623  * NO_DIRECT_COMPLETE: Do not apply direct-complete optimization to the device.
624  * SMART_PREPARE: Take the driver ->prepare callback return value into account.
625  * SMART_SUSPEND: Avoid resuming the device from runtime suspend.
626  * MAY_SKIP_RESUME: Allow driver "noirq" and "early" callbacks to be skipped.
627  *
628  * See Documentation/driver-api/pm/devices.rst for details.
629  */
630 #define DPM_FLAG_NO_DIRECT_COMPLETE	BIT(0)
631 #define DPM_FLAG_SMART_PREPARE		BIT(1)
632 #define DPM_FLAG_SMART_SUSPEND		BIT(2)
633 #define DPM_FLAG_MAY_SKIP_RESUME	BIT(3)
634 
635 struct dev_pm_info {
636 	pm_message_t		power_state;
637 	unsigned int		can_wakeup:1;
638 	unsigned int		async_suspend:1;
639 	bool			in_dpm_list:1;	/* Owned by the PM core */
640 	bool			is_prepared:1;	/* Owned by the PM core */
641 	bool			is_suspended:1;	/* Ditto */
642 	bool			is_noirq_suspended:1;
643 	bool			is_late_suspended:1;
644 	bool			no_pm:1;
645 	bool			early_init:1;	/* Owned by the PM core */
646 	bool			direct_complete:1;	/* Owned by the PM core */
647 	u32			driver_flags;
648 	spinlock_t		lock;
649 #ifdef CONFIG_PM_SLEEP
650 	struct list_head	entry;
651 	struct completion	completion;
652 	struct wakeup_source	*wakeup;
653 	bool			wakeup_path:1;
654 	bool			syscore:1;
655 	bool			no_pm_callbacks:1;	/* Owned by the PM core */
656 	unsigned int		must_resume:1;	/* Owned by the PM core */
657 	unsigned int		may_skip_resume:1;	/* Set by subsystems */
658 #else
659 	unsigned int		should_wakeup:1;
660 #endif
661 #ifdef CONFIG_PM
662 	struct hrtimer		suspend_timer;
663 	u64			timer_expires;
664 	struct work_struct	work;
665 	wait_queue_head_t	wait_queue;
666 	struct wake_irq		*wakeirq;
667 	atomic_t		usage_count;
668 	atomic_t		child_count;
669 	unsigned int		disable_depth:3;
670 	unsigned int		idle_notification:1;
671 	unsigned int		request_pending:1;
672 	unsigned int		deferred_resume:1;
673 	unsigned int		needs_force_resume:1;
674 	unsigned int		runtime_auto:1;
675 	bool			ignore_children:1;
676 	unsigned int		no_callbacks:1;
677 	unsigned int		irq_safe:1;
678 	unsigned int		use_autosuspend:1;
679 	unsigned int		timer_autosuspends:1;
680 	unsigned int		memalloc_noio:1;
681 	unsigned int		links_count;
682 	enum rpm_request	request;
683 	enum rpm_status		runtime_status;
684 	enum rpm_status		last_status;
685 	int			runtime_error;
686 	int			autosuspend_delay;
687 	u64			last_busy;
688 	u64			active_time;
689 	u64			suspended_time;
690 	u64			accounting_timestamp;
691 #endif
692 	struct pm_subsys_data	*subsys_data;  /* Owned by the subsystem. */
693 	void (*set_latency_tolerance)(struct device *, s32);
694 	struct dev_pm_qos	*qos;
695 };
696 
697 extern int dev_pm_get_subsys_data(struct device *dev);
698 extern void dev_pm_put_subsys_data(struct device *dev);
699 
700 /**
701  * struct dev_pm_domain - power management domain representation.
702  *
703  * @ops: Power management operations associated with this domain.
704  * @start: Called when a user needs to start the device via the domain.
705  * @detach: Called when removing a device from the domain.
706  * @activate: Called before executing probe routines for bus types and drivers.
707  * @sync: Called after successful driver probe.
708  * @dismiss: Called after unsuccessful driver probe and after driver removal.
709  *
710  * Power domains provide callbacks that are executed during system suspend,
711  * hibernation, system resume and during runtime PM transitions instead of
712  * subsystem-level and driver-level callbacks.
713  */
714 struct dev_pm_domain {
715 	struct dev_pm_ops	ops;
716 	int (*start)(struct device *dev);
717 	void (*detach)(struct device *dev, bool power_off);
718 	int (*activate)(struct device *dev);
719 	void (*sync)(struct device *dev);
720 	void (*dismiss)(struct device *dev);
721 };
722 
723 /*
724  * The PM_EVENT_ messages are also used by drivers implementing the legacy
725  * suspend framework, based on the ->suspend() and ->resume() callbacks common
726  * for suspend and hibernation transitions, according to the rules below.
727  */
728 
729 /* Necessary, because several drivers use PM_EVENT_PRETHAW */
730 #define PM_EVENT_PRETHAW PM_EVENT_QUIESCE
731 
732 /*
733  * One transition is triggered by resume(), after a suspend() call; the
734  * message is implicit:
735  *
736  * ON		Driver starts working again, responding to hardware events
737  *		and software requests.  The hardware may have gone through
738  *		a power-off reset, or it may have maintained state from the
739  *		previous suspend() which the driver will rely on while
740  *		resuming.  On most platforms, there are no restrictions on
741  *		availability of resources like clocks during resume().
742  *
743  * Other transitions are triggered by messages sent using suspend().  All
744  * these transitions quiesce the driver, so that I/O queues are inactive.
745  * That commonly entails turning off IRQs and DMA; there may be rules
746  * about how to quiesce that are specific to the bus or the device's type.
747  * (For example, network drivers mark the link state.)  Other details may
748  * differ according to the message:
749  *
750  * SUSPEND	Quiesce, enter a low power device state appropriate for
751  *		the upcoming system state (such as PCI_D3hot), and enable
752  *		wakeup events as appropriate.
753  *
754  * HIBERNATE	Enter a low power device state appropriate for the hibernation
755  *		state (eg. ACPI S4) and enable wakeup events as appropriate.
756  *
757  * FREEZE	Quiesce operations so that a consistent image can be saved;
758  *		but do NOT otherwise enter a low power device state, and do
759  *		NOT emit system wakeup events.
760  *
761  * PRETHAW	Quiesce as if for FREEZE; additionally, prepare for restoring
762  *		the system from a snapshot taken after an earlier FREEZE.
763  *		Some drivers will need to reset their hardware state instead
764  *		of preserving it, to ensure that it's never mistaken for the
765  *		state which that earlier snapshot had set up.
766  *
767  * A minimally power-aware driver treats all messages as SUSPEND, fully
768  * reinitializes its device during resume() -- whether or not it was reset
769  * during the suspend/resume cycle -- and can't issue wakeup events.
770  *
771  * More power-aware drivers may also use low power states at runtime as
772  * well as during system sleep states like PM_SUSPEND_STANDBY.  They may
773  * be able to use wakeup events to exit from runtime low-power states,
774  * or from system low-power states such as standby or suspend-to-RAM.
775  */
776 
777 #ifdef CONFIG_PM_SLEEP
778 extern void device_pm_lock(void);
779 extern void dpm_resume_start(pm_message_t state);
780 extern void dpm_resume_end(pm_message_t state);
781 extern void dpm_resume_noirq(pm_message_t state);
782 extern void dpm_resume_early(pm_message_t state);
783 extern void dpm_resume(pm_message_t state);
784 extern void dpm_complete(pm_message_t state);
785 
786 extern void device_pm_unlock(void);
787 extern int dpm_suspend_end(pm_message_t state);
788 extern int dpm_suspend_start(pm_message_t state);
789 extern int dpm_suspend_noirq(pm_message_t state);
790 extern int dpm_suspend_late(pm_message_t state);
791 extern int dpm_suspend(pm_message_t state);
792 extern int dpm_prepare(pm_message_t state);
793 
794 extern void __suspend_report_result(const char *function, struct device *dev, void *fn, int ret);
795 
796 #define suspend_report_result(dev, fn, ret)				\
797 	do {								\
798 		__suspend_report_result(__func__, dev, fn, ret);	\
799 	} while (0)
800 
801 extern int device_pm_wait_for_dev(struct device *sub, struct device *dev);
802 extern void dpm_for_each_dev(void *data, void (*fn)(struct device *, void *));
803 
804 extern int pm_generic_prepare(struct device *dev);
805 extern int pm_generic_suspend_late(struct device *dev);
806 extern int pm_generic_suspend_noirq(struct device *dev);
807 extern int pm_generic_suspend(struct device *dev);
808 extern int pm_generic_resume_early(struct device *dev);
809 extern int pm_generic_resume_noirq(struct device *dev);
810 extern int pm_generic_resume(struct device *dev);
811 extern int pm_generic_freeze_noirq(struct device *dev);
812 extern int pm_generic_freeze_late(struct device *dev);
813 extern int pm_generic_freeze(struct device *dev);
814 extern int pm_generic_thaw_noirq(struct device *dev);
815 extern int pm_generic_thaw_early(struct device *dev);
816 extern int pm_generic_thaw(struct device *dev);
817 extern int pm_generic_restore_noirq(struct device *dev);
818 extern int pm_generic_restore_early(struct device *dev);
819 extern int pm_generic_restore(struct device *dev);
820 extern int pm_generic_poweroff_noirq(struct device *dev);
821 extern int pm_generic_poweroff_late(struct device *dev);
822 extern int pm_generic_poweroff(struct device *dev);
823 extern void pm_generic_complete(struct device *dev);
824 
825 extern bool dev_pm_skip_resume(struct device *dev);
826 extern bool dev_pm_skip_suspend(struct device *dev);
827 
828 #else /* !CONFIG_PM_SLEEP */
829 
830 #define device_pm_lock() do {} while (0)
831 #define device_pm_unlock() do {} while (0)
832 
dpm_suspend_start(pm_message_t state)833 static inline int dpm_suspend_start(pm_message_t state)
834 {
835 	return 0;
836 }
837 
838 #define suspend_report_result(dev, fn, ret)	do {} while (0)
839 
device_pm_wait_for_dev(struct device * a,struct device * b)840 static inline int device_pm_wait_for_dev(struct device *a, struct device *b)
841 {
842 	return 0;
843 }
844 
dpm_for_each_dev(void * data,void (* fn)(struct device *,void *))845 static inline void dpm_for_each_dev(void *data, void (*fn)(struct device *, void *))
846 {
847 }
848 
849 #define pm_generic_prepare		NULL
850 #define pm_generic_suspend_late		NULL
851 #define pm_generic_suspend_noirq	NULL
852 #define pm_generic_suspend		NULL
853 #define pm_generic_resume_early		NULL
854 #define pm_generic_resume_noirq		NULL
855 #define pm_generic_resume		NULL
856 #define pm_generic_freeze_noirq		NULL
857 #define pm_generic_freeze_late		NULL
858 #define pm_generic_freeze		NULL
859 #define pm_generic_thaw_noirq		NULL
860 #define pm_generic_thaw_early		NULL
861 #define pm_generic_thaw			NULL
862 #define pm_generic_restore_noirq	NULL
863 #define pm_generic_restore_early	NULL
864 #define pm_generic_restore		NULL
865 #define pm_generic_poweroff_noirq	NULL
866 #define pm_generic_poweroff_late	NULL
867 #define pm_generic_poweroff		NULL
868 #define pm_generic_complete		NULL
869 #endif /* !CONFIG_PM_SLEEP */
870 
871 /* How to reorder dpm_list after device_move() */
872 enum dpm_order {
873 	DPM_ORDER_NONE,
874 	DPM_ORDER_DEV_AFTER_PARENT,
875 	DPM_ORDER_PARENT_BEFORE_DEV,
876 	DPM_ORDER_DEV_LAST,
877 };
878 
879 #endif /* _LINUX_PM_H */
880