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, license, ns)				\
379  	const struct dev_pm_ops name;					\
380  	__EXPORT_SYMBOL(name, license, ns);				\
381  	const struct dev_pm_ops name
382  #define EXPORT_PM_FN_GPL(name)		EXPORT_SYMBOL_GPL(name)
383  #define EXPORT_PM_FN_NS_GPL(name, ns)	EXPORT_SYMBOL_NS_GPL(name, ns)
384  #else
385  #define _EXPORT_DEV_PM_OPS(name, license, ns)				\
386  	static __maybe_unused const struct dev_pm_ops __static_##name
387  #define EXPORT_PM_FN_GPL(name)
388  #define EXPORT_PM_FN_NS_GPL(name, ns)
389  #endif
390  
391  #define EXPORT_DEV_PM_OPS(name) _EXPORT_DEV_PM_OPS(name, "", "")
392  #define EXPORT_GPL_DEV_PM_OPS(name) _EXPORT_DEV_PM_OPS(name, "GPL", "")
393  #define EXPORT_NS_DEV_PM_OPS(name, ns) _EXPORT_DEV_PM_OPS(name, "", #ns)
394  #define EXPORT_NS_GPL_DEV_PM_OPS(name, ns) _EXPORT_DEV_PM_OPS(name, "GPL", #ns)
395  
396  /*
397   * Use this if you want to use the same suspend and resume callbacks for suspend
398   * to RAM and hibernation.
399   *
400   * If the underlying dev_pm_ops struct symbol has to be exported, use
401   * EXPORT_SIMPLE_DEV_PM_OPS() or EXPORT_GPL_SIMPLE_DEV_PM_OPS() instead.
402   */
403  #define DEFINE_SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn) \
404  	_DEFINE_DEV_PM_OPS(name, suspend_fn, resume_fn, NULL, NULL, NULL)
405  
406  #define EXPORT_SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn) \
407  	EXPORT_DEV_PM_OPS(name) = { \
408  		SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
409  	}
410  #define EXPORT_GPL_SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn) \
411  	EXPORT_GPL_DEV_PM_OPS(name) = { \
412  		SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
413  	}
414  #define EXPORT_NS_SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn, ns)	\
415  	EXPORT_NS_DEV_PM_OPS(name, ns) = { \
416  		SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
417  	}
418  #define EXPORT_NS_GPL_SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn, ns)	\
419  	EXPORT_NS_GPL_DEV_PM_OPS(name, ns) = { \
420  		SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
421  	}
422  
423  /* Deprecated. Use DEFINE_SIMPLE_DEV_PM_OPS() instead. */
424  #define SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn) \
425  const struct dev_pm_ops __maybe_unused name = { \
426  	SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
427  }
428  
429  /*
430   * Use this for defining a set of PM operations to be used in all situations
431   * (system suspend, hibernation or runtime PM).
432   * NOTE: In general, system suspend callbacks, .suspend() and .resume(), should
433   * be different from the corresponding runtime PM callbacks, .runtime_suspend(),
434   * and .runtime_resume(), because .runtime_suspend() always works on an already
435   * quiescent device, while .suspend() should assume that the device may be doing
436   * something when it is called (it should ensure that the device will be
437   * quiescent after it has returned).  Therefore it's better to point the "late"
438   * suspend and "early" resume callback pointers, .suspend_late() and
439   * .resume_early(), to the same routines as .runtime_suspend() and
440   * .runtime_resume(), respectively (and analogously for hibernation).
441   *
442   * Deprecated. You most likely don't want this macro. Use
443   * DEFINE_RUNTIME_DEV_PM_OPS() instead.
444   */
445  #define UNIVERSAL_DEV_PM_OPS(name, suspend_fn, resume_fn, idle_fn) \
446  const struct dev_pm_ops __maybe_unused name = { \
447  	SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
448  	SET_RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn) \
449  }
450  
451  /*
452   * Use this if you want to have the suspend and resume callbacks be called
453   * with IRQs disabled.
454   */
455  #define DEFINE_NOIRQ_DEV_PM_OPS(name, suspend_fn, resume_fn) \
456  const struct dev_pm_ops name = { \
457  	NOIRQ_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
458  }
459  
460  #define pm_ptr(_ptr) PTR_IF(IS_ENABLED(CONFIG_PM), (_ptr))
461  #define pm_sleep_ptr(_ptr) PTR_IF(IS_ENABLED(CONFIG_PM_SLEEP), (_ptr))
462  
463  /*
464   * PM_EVENT_ messages
465   *
466   * The following PM_EVENT_ messages are defined for the internal use of the PM
467   * core, in order to provide a mechanism allowing the high level suspend and
468   * hibernation code to convey the necessary information to the device PM core
469   * code:
470   *
471   * ON		No transition.
472   *
473   * FREEZE	System is going to hibernate, call ->prepare() and ->freeze()
474   *		for all devices.
475   *
476   * SUSPEND	System is going to suspend, call ->prepare() and ->suspend()
477   *		for all devices.
478   *
479   * HIBERNATE	Hibernation image has been saved, call ->prepare() and
480   *		->poweroff() for all devices.
481   *
482   * QUIESCE	Contents of main memory are going to be restored from a (loaded)
483   *		hibernation image, call ->prepare() and ->freeze() for all
484   *		devices.
485   *
486   * RESUME	System is resuming, call ->resume() and ->complete() for all
487   *		devices.
488   *
489   * THAW		Hibernation image has been created, call ->thaw() and
490   *		->complete() for all devices.
491   *
492   * RESTORE	Contents of main memory have been restored from a hibernation
493   *		image, call ->restore() and ->complete() for all devices.
494   *
495   * RECOVER	Creation of a hibernation image or restoration of the main
496   *		memory contents from a hibernation image has failed, call
497   *		->thaw() and ->complete() for all devices.
498   *
499   * The following PM_EVENT_ messages are defined for internal use by
500   * kernel subsystems.  They are never issued by the PM core.
501   *
502   * USER_SUSPEND		Manual selective suspend was issued by userspace.
503   *
504   * USER_RESUME		Manual selective resume was issued by userspace.
505   *
506   * REMOTE_WAKEUP	Remote-wakeup request was received from the device.
507   *
508   * AUTO_SUSPEND		Automatic (device idle) runtime suspend was
509   *			initiated by the subsystem.
510   *
511   * AUTO_RESUME		Automatic (device needed) runtime resume was
512   *			requested by a driver.
513   */
514  
515  #define PM_EVENT_INVALID	(-1)
516  #define PM_EVENT_ON		0x0000
517  #define PM_EVENT_FREEZE		0x0001
518  #define PM_EVENT_SUSPEND	0x0002
519  #define PM_EVENT_HIBERNATE	0x0004
520  #define PM_EVENT_QUIESCE	0x0008
521  #define PM_EVENT_RESUME		0x0010
522  #define PM_EVENT_THAW		0x0020
523  #define PM_EVENT_RESTORE	0x0040
524  #define PM_EVENT_RECOVER	0x0080
525  #define PM_EVENT_USER		0x0100
526  #define PM_EVENT_REMOTE		0x0200
527  #define PM_EVENT_AUTO		0x0400
528  
529  #define PM_EVENT_SLEEP		(PM_EVENT_SUSPEND | PM_EVENT_HIBERNATE)
530  #define PM_EVENT_USER_SUSPEND	(PM_EVENT_USER | PM_EVENT_SUSPEND)
531  #define PM_EVENT_USER_RESUME	(PM_EVENT_USER | PM_EVENT_RESUME)
532  #define PM_EVENT_REMOTE_RESUME	(PM_EVENT_REMOTE | PM_EVENT_RESUME)
533  #define PM_EVENT_AUTO_SUSPEND	(PM_EVENT_AUTO | PM_EVENT_SUSPEND)
534  #define PM_EVENT_AUTO_RESUME	(PM_EVENT_AUTO | PM_EVENT_RESUME)
535  
536  #define PMSG_INVALID	((struct pm_message){ .event = PM_EVENT_INVALID, })
537  #define PMSG_ON		((struct pm_message){ .event = PM_EVENT_ON, })
538  #define PMSG_FREEZE	((struct pm_message){ .event = PM_EVENT_FREEZE, })
539  #define PMSG_QUIESCE	((struct pm_message){ .event = PM_EVENT_QUIESCE, })
540  #define PMSG_SUSPEND	((struct pm_message){ .event = PM_EVENT_SUSPEND, })
541  #define PMSG_HIBERNATE	((struct pm_message){ .event = PM_EVENT_HIBERNATE, })
542  #define PMSG_RESUME	((struct pm_message){ .event = PM_EVENT_RESUME, })
543  #define PMSG_THAW	((struct pm_message){ .event = PM_EVENT_THAW, })
544  #define PMSG_RESTORE	((struct pm_message){ .event = PM_EVENT_RESTORE, })
545  #define PMSG_RECOVER	((struct pm_message){ .event = PM_EVENT_RECOVER, })
546  #define PMSG_USER_SUSPEND	((struct pm_message) \
547  					{ .event = PM_EVENT_USER_SUSPEND, })
548  #define PMSG_USER_RESUME	((struct pm_message) \
549  					{ .event = PM_EVENT_USER_RESUME, })
550  #define PMSG_REMOTE_RESUME	((struct pm_message) \
551  					{ .event = PM_EVENT_REMOTE_RESUME, })
552  #define PMSG_AUTO_SUSPEND	((struct pm_message) \
553  					{ .event = PM_EVENT_AUTO_SUSPEND, })
554  #define PMSG_AUTO_RESUME	((struct pm_message) \
555  					{ .event = PM_EVENT_AUTO_RESUME, })
556  
557  #define PMSG_IS_AUTO(msg)	(((msg).event & PM_EVENT_AUTO) != 0)
558  
559  /*
560   * Device run-time power management status.
561   *
562   * These status labels are used internally by the PM core to indicate the
563   * current status of a device with respect to the PM core operations.  They do
564   * not reflect the actual power state of the device or its status as seen by the
565   * driver.
566   *
567   * RPM_ACTIVE		Device is fully operational.  Indicates that the device
568   *			bus type's ->runtime_resume() callback has completed
569   *			successfully.
570   *
571   * RPM_SUSPENDED	Device bus type's ->runtime_suspend() callback has
572   *			completed successfully.  The device is regarded as
573   *			suspended.
574   *
575   * RPM_RESUMING		Device bus type's ->runtime_resume() callback is being
576   *			executed.
577   *
578   * RPM_SUSPENDING	Device bus type's ->runtime_suspend() callback is being
579   *			executed.
580   */
581  
582  enum rpm_status {
583  	RPM_INVALID = -1,
584  	RPM_ACTIVE = 0,
585  	RPM_RESUMING,
586  	RPM_SUSPENDED,
587  	RPM_SUSPENDING,
588  };
589  
590  /*
591   * Device run-time power management request types.
592   *
593   * RPM_REQ_NONE		Do nothing.
594   *
595   * RPM_REQ_IDLE		Run the device bus type's ->runtime_idle() callback
596   *
597   * RPM_REQ_SUSPEND	Run the device bus type's ->runtime_suspend() callback
598   *
599   * RPM_REQ_AUTOSUSPEND	Same as RPM_REQ_SUSPEND, but not until the device has
600   *			been inactive for as long as power.autosuspend_delay
601   *
602   * RPM_REQ_RESUME	Run the device bus type's ->runtime_resume() callback
603   */
604  
605  enum rpm_request {
606  	RPM_REQ_NONE = 0,
607  	RPM_REQ_IDLE,
608  	RPM_REQ_SUSPEND,
609  	RPM_REQ_AUTOSUSPEND,
610  	RPM_REQ_RESUME,
611  };
612  
613  struct wakeup_source;
614  struct wake_irq;
615  struct pm_domain_data;
616  
617  struct pm_subsys_data {
618  	spinlock_t lock;
619  	unsigned int refcount;
620  #ifdef CONFIG_PM_CLK
621  	unsigned int clock_op_might_sleep;
622  	struct mutex clock_mutex;
623  	struct list_head clock_list;
624  #endif
625  #ifdef CONFIG_PM_GENERIC_DOMAINS
626  	struct pm_domain_data *domain_data;
627  #endif
628  };
629  
630  /*
631   * Driver flags to control system suspend/resume behavior.
632   *
633   * These flags can be set by device drivers at the probe time.  They need not be
634   * cleared by the drivers as the driver core will take care of that.
635   *
636   * NO_DIRECT_COMPLETE: Do not apply direct-complete optimization to the device.
637   * SMART_PREPARE: Take the driver ->prepare callback return value into account.
638   * SMART_SUSPEND: Avoid resuming the device from runtime suspend.
639   * MAY_SKIP_RESUME: Allow driver "noirq" and "early" callbacks to be skipped.
640   *
641   * See Documentation/driver-api/pm/devices.rst for details.
642   */
643  #define DPM_FLAG_NO_DIRECT_COMPLETE	BIT(0)
644  #define DPM_FLAG_SMART_PREPARE		BIT(1)
645  #define DPM_FLAG_SMART_SUSPEND		BIT(2)
646  #define DPM_FLAG_MAY_SKIP_RESUME	BIT(3)
647  
648  struct dev_pm_info {
649  	pm_message_t		power_state;
650  	unsigned int		can_wakeup:1;
651  	unsigned int		async_suspend:1;
652  	bool			in_dpm_list:1;	/* Owned by the PM core */
653  	bool			is_prepared:1;	/* Owned by the PM core */
654  	bool			is_suspended:1;	/* Ditto */
655  	bool			is_noirq_suspended:1;
656  	bool			is_late_suspended:1;
657  	bool			no_pm:1;
658  	bool			early_init:1;	/* Owned by the PM core */
659  	bool			direct_complete:1;	/* Owned by the PM core */
660  	u32			driver_flags;
661  	spinlock_t		lock;
662  #ifdef CONFIG_PM_SLEEP
663  	struct list_head	entry;
664  	struct completion	completion;
665  	struct wakeup_source	*wakeup;
666  	bool			wakeup_path:1;
667  	bool			syscore:1;
668  	bool			no_pm_callbacks:1;	/* Owned by the PM core */
669  	unsigned int		must_resume:1;	/* Owned by the PM core */
670  	unsigned int		may_skip_resume:1;	/* Set by subsystems */
671  #else
672  	unsigned int		should_wakeup:1;
673  #endif
674  #ifdef CONFIG_PM
675  	struct hrtimer		suspend_timer;
676  	u64			timer_expires;
677  	struct work_struct	work;
678  	wait_queue_head_t	wait_queue;
679  	struct wake_irq		*wakeirq;
680  	atomic_t		usage_count;
681  	atomic_t		child_count;
682  	unsigned int		disable_depth:3;
683  	unsigned int		idle_notification:1;
684  	unsigned int		request_pending:1;
685  	unsigned int		deferred_resume:1;
686  	unsigned int		needs_force_resume:1;
687  	unsigned int		runtime_auto:1;
688  	bool			ignore_children:1;
689  	unsigned int		no_callbacks:1;
690  	unsigned int		irq_safe:1;
691  	unsigned int		use_autosuspend:1;
692  	unsigned int		timer_autosuspends:1;
693  	unsigned int		memalloc_noio:1;
694  	unsigned int		links_count;
695  	enum rpm_request	request;
696  	enum rpm_status		runtime_status;
697  	enum rpm_status		last_status;
698  	int			runtime_error;
699  	int			autosuspend_delay;
700  	u64			last_busy;
701  	u64			active_time;
702  	u64			suspended_time;
703  	u64			accounting_timestamp;
704  #endif
705  	struct pm_subsys_data	*subsys_data;  /* Owned by the subsystem. */
706  	void (*set_latency_tolerance)(struct device *, s32);
707  	struct dev_pm_qos	*qos;
708  };
709  
710  extern int dev_pm_get_subsys_data(struct device *dev);
711  extern void dev_pm_put_subsys_data(struct device *dev);
712  
713  /**
714   * struct dev_pm_domain - power management domain representation.
715   *
716   * @ops: Power management operations associated with this domain.
717   * @start: Called when a user needs to start the device via the domain.
718   * @detach: Called when removing a device from the domain.
719   * @activate: Called before executing probe routines for bus types and drivers.
720   * @sync: Called after successful driver probe.
721   * @dismiss: Called after unsuccessful driver probe and after driver removal.
722   *
723   * Power domains provide callbacks that are executed during system suspend,
724   * hibernation, system resume and during runtime PM transitions instead of
725   * subsystem-level and driver-level callbacks.
726   */
727  struct dev_pm_domain {
728  	struct dev_pm_ops	ops;
729  	int (*start)(struct device *dev);
730  	void (*detach)(struct device *dev, bool power_off);
731  	int (*activate)(struct device *dev);
732  	void (*sync)(struct device *dev);
733  	void (*dismiss)(struct device *dev);
734  };
735  
736  /*
737   * The PM_EVENT_ messages are also used by drivers implementing the legacy
738   * suspend framework, based on the ->suspend() and ->resume() callbacks common
739   * for suspend and hibernation transitions, according to the rules below.
740   */
741  
742  /* Necessary, because several drivers use PM_EVENT_PRETHAW */
743  #define PM_EVENT_PRETHAW PM_EVENT_QUIESCE
744  
745  /*
746   * One transition is triggered by resume(), after a suspend() call; the
747   * message is implicit:
748   *
749   * ON		Driver starts working again, responding to hardware events
750   *		and software requests.  The hardware may have gone through
751   *		a power-off reset, or it may have maintained state from the
752   *		previous suspend() which the driver will rely on while
753   *		resuming.  On most platforms, there are no restrictions on
754   *		availability of resources like clocks during resume().
755   *
756   * Other transitions are triggered by messages sent using suspend().  All
757   * these transitions quiesce the driver, so that I/O queues are inactive.
758   * That commonly entails turning off IRQs and DMA; there may be rules
759   * about how to quiesce that are specific to the bus or the device's type.
760   * (For example, network drivers mark the link state.)  Other details may
761   * differ according to the message:
762   *
763   * SUSPEND	Quiesce, enter a low power device state appropriate for
764   *		the upcoming system state (such as PCI_D3hot), and enable
765   *		wakeup events as appropriate.
766   *
767   * HIBERNATE	Enter a low power device state appropriate for the hibernation
768   *		state (eg. ACPI S4) and enable wakeup events as appropriate.
769   *
770   * FREEZE	Quiesce operations so that a consistent image can be saved;
771   *		but do NOT otherwise enter a low power device state, and do
772   *		NOT emit system wakeup events.
773   *
774   * PRETHAW	Quiesce as if for FREEZE; additionally, prepare for restoring
775   *		the system from a snapshot taken after an earlier FREEZE.
776   *		Some drivers will need to reset their hardware state instead
777   *		of preserving it, to ensure that it's never mistaken for the
778   *		state which that earlier snapshot had set up.
779   *
780   * A minimally power-aware driver treats all messages as SUSPEND, fully
781   * reinitializes its device during resume() -- whether or not it was reset
782   * during the suspend/resume cycle -- and can't issue wakeup events.
783   *
784   * More power-aware drivers may also use low power states at runtime as
785   * well as during system sleep states like PM_SUSPEND_STANDBY.  They may
786   * be able to use wakeup events to exit from runtime low-power states,
787   * or from system low-power states such as standby or suspend-to-RAM.
788   */
789  
790  #ifdef CONFIG_PM_SLEEP
791  extern void device_pm_lock(void);
792  extern void dpm_resume_start(pm_message_t state);
793  extern void dpm_resume_end(pm_message_t state);
794  extern void dpm_resume_noirq(pm_message_t state);
795  extern void dpm_resume_early(pm_message_t state);
796  extern void dpm_resume(pm_message_t state);
797  extern void dpm_complete(pm_message_t state);
798  
799  extern void device_pm_unlock(void);
800  extern int dpm_suspend_end(pm_message_t state);
801  extern int dpm_suspend_start(pm_message_t state);
802  extern int dpm_suspend_noirq(pm_message_t state);
803  extern int dpm_suspend_late(pm_message_t state);
804  extern int dpm_suspend(pm_message_t state);
805  extern int dpm_prepare(pm_message_t state);
806  
807  extern void __suspend_report_result(const char *function, struct device *dev, void *fn, int ret);
808  
809  #define suspend_report_result(dev, fn, ret)				\
810  	do {								\
811  		__suspend_report_result(__func__, dev, fn, ret);	\
812  	} while (0)
813  
814  extern int device_pm_wait_for_dev(struct device *sub, struct device *dev);
815  extern void dpm_for_each_dev(void *data, void (*fn)(struct device *, void *));
816  
817  extern int pm_generic_prepare(struct device *dev);
818  extern int pm_generic_suspend_late(struct device *dev);
819  extern int pm_generic_suspend_noirq(struct device *dev);
820  extern int pm_generic_suspend(struct device *dev);
821  extern int pm_generic_resume_early(struct device *dev);
822  extern int pm_generic_resume_noirq(struct device *dev);
823  extern int pm_generic_resume(struct device *dev);
824  extern int pm_generic_freeze_noirq(struct device *dev);
825  extern int pm_generic_freeze_late(struct device *dev);
826  extern int pm_generic_freeze(struct device *dev);
827  extern int pm_generic_thaw_noirq(struct device *dev);
828  extern int pm_generic_thaw_early(struct device *dev);
829  extern int pm_generic_thaw(struct device *dev);
830  extern int pm_generic_restore_noirq(struct device *dev);
831  extern int pm_generic_restore_early(struct device *dev);
832  extern int pm_generic_restore(struct device *dev);
833  extern int pm_generic_poweroff_noirq(struct device *dev);
834  extern int pm_generic_poweroff_late(struct device *dev);
835  extern int pm_generic_poweroff(struct device *dev);
836  extern void pm_generic_complete(struct device *dev);
837  
838  extern bool dev_pm_skip_resume(struct device *dev);
839  extern bool dev_pm_skip_suspend(struct device *dev);
840  
841  #else /* !CONFIG_PM_SLEEP */
842  
843  #define device_pm_lock() do {} while (0)
844  #define device_pm_unlock() do {} while (0)
845  
dpm_suspend_start(pm_message_t state)846  static inline int dpm_suspend_start(pm_message_t state)
847  {
848  	return 0;
849  }
850  
851  #define suspend_report_result(dev, fn, ret)	do {} while (0)
852  
device_pm_wait_for_dev(struct device * a,struct device * b)853  static inline int device_pm_wait_for_dev(struct device *a, struct device *b)
854  {
855  	return 0;
856  }
857  
dpm_for_each_dev(void * data,void (* fn)(struct device *,void *))858  static inline void dpm_for_each_dev(void *data, void (*fn)(struct device *, void *))
859  {
860  }
861  
862  #define pm_generic_prepare		NULL
863  #define pm_generic_suspend_late		NULL
864  #define pm_generic_suspend_noirq	NULL
865  #define pm_generic_suspend		NULL
866  #define pm_generic_resume_early		NULL
867  #define pm_generic_resume_noirq		NULL
868  #define pm_generic_resume		NULL
869  #define pm_generic_freeze_noirq		NULL
870  #define pm_generic_freeze_late		NULL
871  #define pm_generic_freeze		NULL
872  #define pm_generic_thaw_noirq		NULL
873  #define pm_generic_thaw_early		NULL
874  #define pm_generic_thaw			NULL
875  #define pm_generic_restore_noirq	NULL
876  #define pm_generic_restore_early	NULL
877  #define pm_generic_restore		NULL
878  #define pm_generic_poweroff_noirq	NULL
879  #define pm_generic_poweroff_late	NULL
880  #define pm_generic_poweroff		NULL
881  #define pm_generic_complete		NULL
882  #endif /* !CONFIG_PM_SLEEP */
883  
884  /* How to reorder dpm_list after device_move() */
885  enum dpm_order {
886  	DPM_ORDER_NONE,
887  	DPM_ORDER_DEV_AFTER_PARENT,
888  	DPM_ORDER_PARENT_BEFORE_DEV,
889  	DPM_ORDER_DEV_LAST,
890  };
891  
892  #endif /* _LINUX_PM_H */
893