text: /*
   *  pm.h - Power management interface
   *
   *  Copyright (C) 2000 Andrew Henroid
   *
   *  This program is free software; you can redistribute it and/or modify
   *  it under the terms of the GNU General Public License as published by
   *  the Free Software Foundation; either version 2 of the License, or
   *  (at your option) any later version.
   *
   *  This program is distributed in the hope that it will be useful,
   *  but WITHOUT ANY WARRANTY; without even the implied warranty of
   *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   *  GNU General Public License for more details.
   *
   *  You should have received a copy of the GNU General Public License
   *  along with this program; if not, write to the Free Software
   *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   */
  
  #ifndef _LINUX_PM_H
  #define _LINUX_PM_H
  
  #include <linux/list.h>
  #include <linux/workqueue.h>
  #include <linux/spinlock.h>
  #include <linux/wait.h>
  #include <linux/timer.h>
  #include <linux/hrtimer.h>
  #include <linux/completion.h>
  
  /*
   * Callbacks for platform drivers to implement.
   */
  extern void (*pm_power_off)(void);
  extern void (*pm_power_off_prepare)(void);
  
  struct device; /* we have a circular dep with device.h */
  #ifdef CONFIG_VT_CONSOLE_SLEEP
  extern void pm_vt_switch_required(struct device *dev, bool required);
  extern void pm_vt_switch_unregister(struct device *dev);
  #else
  static inline void pm_vt_switch_required(struct device *dev, bool required)
  {
  }
  static inline void pm_vt_switch_unregister(struct device *dev)
  {
  }
  #endif /* CONFIG_VT_CONSOLE_SLEEP */
  
  /*
   * Device power management
   */
  
  struct device;
  
  #ifdef CONFIG_PM
  extern const char power_group_name[];		/* = "power" */
  #else
  #define power_group_name	NULL
  #endif
  
  typedef struct pm_message {
  	int event;
  } pm_message_t;
  
  /**
   * struct dev_pm_ops - device PM callbacks.
   *
   * @prepare: The principal role of this callback is to prevent new children of
   *	the device from being registered after it has returned (the driver's
   *	subsystem and generally the rest of the kernel is supposed to prevent
   *	new calls to the probe method from being made too once @prepare() has
   *	succeeded).  If @prepare() detects a situation it cannot handle (e.g.
   *	registration of a child already in progress), it may return -EAGAIN, so
   *	that the PM core can execute it once again (e.g. after a new child has
   *	been registered) to recover from the race condition.
   *	This method is executed for all kinds of suspend transitions and is
   *	followed by one of the suspend callbacks: @suspend(), @freeze(), or
   *	@poweroff().  If the transition is a suspend to memory or standby (that
   *	is, not related to hibernation), the return value of @prepare() may be
   *	used to indicate to the PM core to leave the device in runtime suspend
   *	if applicable.  Namely, if @prepare() returns a positive number, the PM
   *	core will understand that as a declaration that the device appears to be
   *	runtime-suspended and it may be left in that state during the entire
   *	transition and during the subsequent resume if all of its descendants
   *	are left in runtime suspend too.  If that happens, @complete() will be
   *	executed directly after @prepare() and it must ensure the proper
   *	functioning of the device after the system resume.
   *	The PM core executes subsystem-level @prepare() for all devices before
   *	starting to invoke suspend callbacks for any of them, so generally
   *	devices may be assumed to be functional or to respond to runtime resume
   *	requests while @prepare() is being executed.  However, device drivers
   *	may NOT assume anything about the availability of user space at that
   *	time and it is NOT valid to request firmware from within @prepare()
   *	(it's too late to do that).  It also is NOT valid to allocate
   *	substantial amounts of memory from @prepare() in the GFP_KERNEL mode.
   *	[To work around these limitations, drivers may register suspend and
   *	hibernation notifiers to be executed before the freezing of tasks.]
   *
   * @complete: Undo the changes made by @prepare().  This method is executed for
   *	all kinds of resume transitions, following one of the resume callbacks:
   *	@resume(), @thaw(), @restore().  Also called if the state transition
   *	fails before the driver's suspend callback: @suspend(), @freeze() or
   *	@poweroff(), can be executed (e.g. if the suspend callback fails for one
   *	of the other devices that the PM core has unsuccessfully attempted to
   *	suspend earlier).
   *	The PM core executes subsystem-level @complete() after it has executed
   *	the appropriate resume callbacks for all devices.  If the corresponding
   *	@prepare() at the beginning of the suspend transition returned a
   *	positive number and the device was left in runtime suspend (without
   *	executing any suspend and resume callbacks for it), @complete() will be
   *	the only callback executed for the device during resume.  In that case,
   *	@complete() must be prepared to do whatever is necessary to ensure the
   *	proper functioning of the device after the system resume.  To this end,
   *	@complete() can check the power.direct_complete flag of the device to
   *	learn whether (unset) or not (set) the previous suspend and resume
   *	callbacks have been executed for it.
   *
   * @suspend: Executed before putting the system into a sleep state in which the
   *	contents of main memory are preserved.  The exact action to perform
   *	depends on the device's subsystem (PM domain, device type, class or bus
   *	type), but generally the device must be quiescent after subsystem-level
   *	@suspend() has returned, so that it doesn't do any I/O or DMA.
   *	Subsystem-level @suspend() is executed for all devices after invoking
   *	subsystem-level @prepare() for all of them.
   *
   * @suspend_late: Continue operations started by @suspend().  For a number of
   *	devices @suspend_late() may point to the same callback routine as the
   *	runtime suspend callback.
   *
   * @resume: Executed after waking the system up from a sleep state in which the
   *	contents of main memory were preserved.  The exact action to perform
   *	depends on the device's subsystem, but generally the driver is expected
   *	to start working again, responding to hardware events and software
   *	requests (the device itself may be left in a low-power state, waiting
   *	for a runtime resume to occur).  The state of the device at the time its
   *	driver's @resume() callback is run depends on the platform and subsystem
   *	the device belongs to.  On most platforms, there are no restrictions on
   *	availability of resources like clocks during @resume().
   *	Subsystem-level @resume() is executed for all devices after invoking
   *	subsystem-level @resume_noirq() for all of them.
   *
   * @resume_early: Prepare to execute @resume().  For a number of devices
   *	@resume_early() may point to the same callback routine as the runtime
   *	resume callback.
   *
   * @freeze: Hibernation-specific, executed before creating a hibernation image.
   *	Analogous to @suspend(), but it should not enable the device to signal
   *	wakeup events or change its power state.  The majority of subsystems
   *	(with the notable exception of the PCI bus type) expect the driver-level
   *	@freeze() to save the device settings in memory to be used by @restore()
   *	during the subsequent resume from hibernation.
   *	Subsystem-level @freeze() is executed for all devices after invoking
   *	subsystem-level @prepare() for all of them.
   *
   * @freeze_late: Continue operations started by @freeze().  Analogous to
   *	@suspend_late(), but it should not enable the device to signal wakeup
   *	events or change its power state.
   *
   * @thaw: Hibernation-specific, executed after creating a hibernation image OR
   *	if the creation of an image has failed.  Also executed after a failing
   *	attempt to restore the contents of main memory from such an image.
   *	Undo the changes made by the preceding @freeze(), so the device can be
   *	operated in the same way as immediately before the call to @freeze().
   *	Subsystem-level @thaw() is executed for all devices after invoking
   *	subsystem-level @thaw_noirq() for all of them.  It also may be executed
   *	directly after @freeze() in case of a transition error.
   *
   * @thaw_early: Prepare to execute @thaw().  Undo the changes made by the
   *	preceding @freeze_late().
   *
   * @poweroff: Hibernation-specific, executed after saving a hibernation image.
   *	Analogous to @suspend(), but it need not save the device's settings in
   *	memory.
   *	Subsystem-level @poweroff() is executed for all devices after invoking
   *	subsystem-level @prepare() for all of them.
   *
   * @poweroff_late: Continue operations started by @poweroff().  Analogous to
   *	@suspend_late(), but it need not save the device's settings in memory.
   *
   * @restore: Hibernation-specific, executed after restoring the contents of main
   *	memory from a hibernation image, analogous to @resume().
   *
   * @restore_early: Prepare to execute @restore(), analogous to @resume_early().
   *
   * @suspend_noirq: Complete the actions started by @suspend().  Carry out any
   *	additional operations required for suspending the device that might be
   *	racing with its driver's interrupt handler, which is guaranteed not to
   *	run while @suspend_noirq() is being executed.
   *	It generally is expected that the device will be in a low-power state
   *	(appropriate for the target system sleep state) after subsystem-level
   *	@suspend_noirq() has returned successfully.  If the device can generate
   *	system wakeup signals and is enabled to wake up the system, it should be
   *	configured to do so at that time.  However, depending on the platform
   *	and device's subsystem, @suspend() or @suspend_late() may be allowed to
   *	put the device into the low-power state and configure it to generate
   *	wakeup signals, in which case it generally is not necessary to define
   *	@suspend_noirq().
   *
   * @resume_noirq: Prepare for the execution of @resume() by carrying out any
   *	operations required for resuming the device that might be racing with
   *	its driver's interrupt handler, which is guaranteed not to run while
   *	@resume_noirq() is being executed.
   *
   * @freeze_noirq: Complete the actions started by @freeze().  Carry out any
   *	additional operations required for freezing the device that might be
   *	racing with its driver's interrupt handler, which is guaranteed not to
   *	run while @freeze_noirq() is being executed.
   *	The power state of the device should not be changed by either @freeze(),
   *	or @freeze_late(), or @freeze_noirq() and it should not be configured to
   *	signal system wakeup by any of these callbacks.
   *
   * @thaw_noirq: Prepare for the execution of @thaw() by carrying out any
   *	operations required for thawing the device that might be racing with its
   *	driver's interrupt handler, which is guaranteed not to run while
   *	@thaw_noirq() is being executed.
   *
   * @poweroff_noirq: Complete the actions started by @poweroff().  Analogous to
   *	@suspend_noirq(), but it need not save the device's settings in memory.
   *
   * @restore_noirq: Prepare for the execution of @restore() by carrying out any
   *	operations required for thawing the device that might be racing with its
   *	driver's interrupt handler, which is guaranteed not to run while
   *	@restore_noirq() is being executed.  Analogous to @resume_noirq().
   *
   * @runtime_suspend: Prepare the device for a condition in which it won't be
   *	able to communicate with the CPU(s) and RAM due to power management.
   *	This need not mean that the device should be put into a low-power state.
   *	For example, if the device is behind a link which is about to be turned
   *	off, the device may remain at full power.  If the device does go to low
   *	power and is capable of generating runtime wakeup events, remote wakeup
   *	(i.e., a hardware mechanism allowing the device to request a change of
   *	its power state via an interrupt) should be enabled for it.
   *
   * @runtime_resume: Put the device into the fully active state in response to a
   *	wakeup event generated by hardware or at the request of software.  If
   *	necessary, put the device into the full-power state and restore its
   *	registers, so that it is fully operational.
   *
   * @runtime_idle: Device appears to be inactive and it might be put into a
   *	low-power state if all of the necessary conditions are satisfied.
   *	Check these conditions, and return 0 if it's appropriate to let the PM
   *	core queue a suspend request for the device.
   *
   * Several device power state transitions are externally visible, affecting
   * the state of pending I/O queues and (for drivers that touch hardware)
   * interrupts, wakeups, DMA, and other hardware state.  There may also be
   * internal transitions to various low-power modes which are transparent
   * to the rest of the driver stack (such as a driver that's ON gating off
   * clocks which are not in active use).
   *
   * The externally visible transitions are handled with the help of callbacks
   * included in this structure in such a way that, typically, two levels of
   * callbacks are involved.  First, the PM core executes callbacks provided by PM
   * domains, device types, classes and bus types.  They are the subsystem-level
   * callbacks expected to execute callbacks provided by device drivers, although
   * they may choose not to do that.  If the driver callbacks are executed, they
   * have to collaborate with the subsystem-level callbacks to achieve the goals
   * appropriate for the given system transition, given transition phase and the
   * subsystem the device belongs to.
   *
   * All of the above callbacks, except for @complete(), return error codes.
   * However, the error codes returned by @resume(), @thaw(), @restore(),
   * @resume_noirq(), @thaw_noirq(), and @restore_noirq(), do not cause the PM
   * core to abort the resume transition during which they are returned.  The
   * error codes returned in those cases are only printed to the system logs for
   * debugging purposes.  Still, it is recommended that drivers only return error
   * codes from their resume methods in case of an unrecoverable failure (i.e.
   * when the device being handled refuses to resume and becomes unusable) to
   * allow the PM core to be modified in the future, so that it can avoid
   * attempting to handle devices that failed to resume and their children.
   *
   * It is allowed to unregister devices while the above callbacks are being
   * executed.  However, a callback routine MUST NOT try to unregister the device
   * it was called for, although it may unregister children of that device (for
   * example, if it detects that a child was unplugged while the system was
   * asleep).
   *
   * There also are callbacks related to runtime power management of devices.
   * Again, as a rule these callbacks are executed by the PM core for subsystems
   * (PM domains, device types, classes and bus types) and the subsystem-level
   * callbacks are expected to invoke the driver callbacks.  Moreover, the exact
   * actions to be performed by a device driver's callbacks generally depend on
   * the platform and subsystem the device belongs to.
   *
   * Refer to Documentation/power/runtime_pm.txt for more information about the
   * role of the @runtime_suspend(), @runtime_resume() and @runtime_idle()
   * callbacks in device runtime power management.
   */
  struct dev_pm_ops {
  	int (*prepare)(struct device *dev);
  	void (*complete)(struct device *dev);
  	int (*suspend)(struct device *dev);
  	int (*resume)(struct device *dev);
  	int (*freeze)(struct device *dev);
  	int (*thaw)(struct device *dev);
  	int (*poweroff)(struct device *dev);
  	int (*restore)(struct device *dev);
  	int (*suspend_late)(struct device *dev);
  	int (*resume_early)(struct device *dev);
  	int (*freeze_late)(struct device *dev);
  	int (*thaw_early)(struct device *dev);
  	int (*poweroff_late)(struct device *dev);
  	int (*restore_early)(struct device *dev);
  	int (*suspend_noirq)(struct device *dev);
  	int (*resume_noirq)(struct device *dev);
  	int (*freeze_noirq)(struct device *dev);
  	int (*thaw_noirq)(struct device *dev);
  	int (*poweroff_noirq)(struct device *dev);
  	int (*restore_noirq)(struct device *dev);
  	int (*runtime_suspend)(struct device *dev);
  	int (*runtime_resume)(struct device *dev);
  	int (*runtime_idle)(struct device *dev);
  };
  
  #ifdef CONFIG_PM_SLEEP
  #define SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
  	.suspend = suspend_fn, \
  	.resume = resume_fn, \
  	.freeze = suspend_fn, \
  	.thaw = resume_fn, \
  	.poweroff = suspend_fn, \
  	.restore = resume_fn,
  #else
  #define SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn)
  #endif
  
  #ifdef CONFIG_PM_SLEEP
  #define SET_LATE_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
  	.suspend_late = suspend_fn, \
  	.resume_early = resume_fn, \
  	.freeze_late = suspend_fn, \
  	.thaw_early = resume_fn, \
  	.poweroff_late = suspend_fn, \
  	.restore_early = resume_fn,
  #else
  #define SET_LATE_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn)
  #endif
  
  #ifdef CONFIG_PM_SLEEP
  #define SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
  	.suspend_noirq = suspend_fn, \
  	.resume_noirq = resume_fn, \
  	.freeze_noirq = suspend_fn, \
  	.thaw_noirq = resume_fn, \
  	.poweroff_noirq = suspend_fn, \
  	.restore_noirq = resume_fn,
  #else
  #define SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn)
  #endif
  
  #ifdef CONFIG_PM
  #define SET_RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn) \
  	.runtime_suspend = suspend_fn, \
  	.runtime_resume = resume_fn, \
  	.runtime_idle = idle_fn,
  #else
  #define SET_RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn)
  #endif
  
  /*
   * Use this if you want to use the same suspend and resume callbacks for suspend
   * to RAM and hibernation.
   */
  #define SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn) \
  const struct dev_pm_ops name = { \
  	SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
  }
  
  /*
   * Use this for defining a set of PM operations to be used in all situations
   * (system suspend, hibernation or runtime PM).
   * NOTE: In general, system suspend callbacks, .suspend() and .resume(), should
   * be different from the corresponding runtime PM callbacks, .runtime_suspend(),
   * and .runtime_resume(), because .runtime_suspend() always works on an already
   * quiescent device, while .suspend() should assume that the device may be doing
   * something when it is called (it should ensure that the device will be
   * quiescent after it has returned).  Therefore it's better to point the "late"
   * suspend and "early" resume callback pointers, .suspend_late() and
   * .resume_early(), to the same routines as .runtime_suspend() and
   * .runtime_resume(), respectively (and analogously for hibernation).
   */
  #define UNIVERSAL_DEV_PM_OPS(name, suspend_fn, resume_fn, idle_fn) \
  const struct dev_pm_ops name = { \
  	SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
  	SET_RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn) \
  }
  
  /*
   * PM_EVENT_ messages
   *
   * The following PM_EVENT_ messages are defined for the internal use of the PM
   * core, in order to provide a mechanism allowing the high level suspend and
   * hibernation code to convey the necessary information to the device PM core
   * code:
   *
   * ON		No transition.
   *
   * FREEZE	System is going to hibernate, call ->prepare() and ->freeze()
   *		for all devices.
   *
   * SUSPEND	System is going to suspend, call ->prepare() and ->suspend()
   *		for all devices.
   *
   * HIBERNATE	Hibernation image has been saved, call ->prepare() and
   *		->poweroff() for all devices.
   *
   * QUIESCE	Contents of main memory are going to be restored from a (loaded)
   *		hibernation image, call ->prepare() and ->freeze() for all
   *		devices.
   *
   * RESUME	System is resuming, call ->resume() and ->complete() for all
   *		devices.
   *
   * THAW		Hibernation image has been created, call ->thaw() and
   *		->complete() for all devices.
   *
   * RESTORE	Contents of main memory have been restored from a hibernation
   *		image, call ->restore() and ->complete() for all devices.
   *
   * RECOVER	Creation of a hibernation image or restoration of the main
   *		memory contents from a hibernation image has failed, call
   *		->thaw() and ->complete() for all devices.
   *
   * The following PM_EVENT_ messages are defined for internal use by
   * kernel subsystems.  They are never issued by the PM core.
   *
   * USER_SUSPEND		Manual selective suspend was issued by userspace.
   *
   * USER_RESUME		Manual selective resume was issued by userspace.
   *
   * REMOTE_WAKEUP	Remote-wakeup request was received from the device.
   *
   * AUTO_SUSPEND		Automatic (device idle) runtime suspend was
   *			initiated by the subsystem.
   *
   * AUTO_RESUME		Automatic (device needed) runtime resume was
   *			requested by a driver.
   */
  
  #define PM_EVENT_INVALID	(-1)
  #define PM_EVENT_ON		0x0000
  #define PM_EVENT_FREEZE		0x0001
  #define PM_EVENT_SUSPEND	0x0002
  #define PM_EVENT_HIBERNATE	0x0004
  #define PM_EVENT_QUIESCE	0x0008
  #define PM_EVENT_RESUME		0x0010
  #define PM_EVENT_THAW		0x0020
  #define PM_EVENT_RESTORE	0x0040
  #define PM_EVENT_RECOVER	0x0080
  #define PM_EVENT_USER		0x0100
  #define PM_EVENT_REMOTE		0x0200
  #define PM_EVENT_AUTO		0x0400
  
  #define PM_EVENT_SLEEP		(PM_EVENT_SUSPEND | PM_EVENT_HIBERNATE)
  #define PM_EVENT_USER_SUSPEND	(PM_EVENT_USER | PM_EVENT_SUSPEND)
  #define PM_EVENT_USER_RESUME	(PM_EVENT_USER | PM_EVENT_RESUME)
  #define PM_EVENT_REMOTE_RESUME	(PM_EVENT_REMOTE | PM_EVENT_RESUME)
  #define PM_EVENT_AUTO_SUSPEND	(PM_EVENT_AUTO | PM_EVENT_SUSPEND)
  #define PM_EVENT_AUTO_RESUME	(PM_EVENT_AUTO | PM_EVENT_RESUME)
  
  #define PMSG_INVALID	((struct pm_message){ .event = PM_EVENT_INVALID, })
  #define PMSG_ON		((struct pm_message){ .event = PM_EVENT_ON, })
  #define PMSG_FREEZE	((struct pm_message){ .event = PM_EVENT_FREEZE, })
  #define PMSG_QUIESCE	((struct pm_message){ .event = PM_EVENT_QUIESCE, })
  #define PMSG_SUSPEND	((struct pm_message){ .event = PM_EVENT_SUSPEND, })
  #define PMSG_HIBERNATE	((struct pm_message){ .event = PM_EVENT_HIBERNATE, })
  #define PMSG_RESUME	((struct pm_message){ .event = PM_EVENT_RESUME, })
  #define PMSG_THAW	((struct pm_message){ .event = PM_EVENT_THAW, })
  #define PMSG_RESTORE	((struct pm_message){ .event = PM_EVENT_RESTORE, })
  #define PMSG_RECOVER	((struct pm_message){ .event = PM_EVENT_RECOVER, })
  #define PMSG_USER_SUSPEND	((struct pm_message) \
  					{ .event = PM_EVENT_USER_SUSPEND, })
  #define PMSG_USER_RESUME	((struct pm_message) \
  					{ .event = PM_EVENT_USER_RESUME, })
  #define PMSG_REMOTE_RESUME	((struct pm_message) \
  					{ .event = PM_EVENT_REMOTE_RESUME, })
  #define PMSG_AUTO_SUSPEND	((struct pm_message) \
  					{ .event = PM_EVENT_AUTO_SUSPEND, })
  #define PMSG_AUTO_RESUME	((struct pm_message) \
  					{ .event = PM_EVENT_AUTO_RESUME, })
  
  #define PMSG_IS_AUTO(msg)	(((msg).event & PM_EVENT_AUTO) != 0)
  
  /*
   * Device run-time power management status.
   *
   * These status labels are used internally by the PM core to indicate the
   * current status of a device with respect to the PM core operations.  They do
   * not reflect the actual power state of the device or its status as seen by the
   * driver.
   *
   * RPM_ACTIVE		Device is fully operational.  Indicates that the device
   *			bus type's ->runtime_resume() callback has completed
   *			successfully.
   *
   * RPM_SUSPENDED	Device bus type's ->runtime_suspend() callback has
   *			completed successfully.  The device is regarded as
   *			suspended.
   *
   * RPM_RESUMING		Device bus type's ->runtime_resume() callback is being
   *			executed.
   *
   * RPM_SUSPENDING	Device bus type's ->runtime_suspend() callback is being
   *			executed.
   */
  
  enum rpm_status {
  	RPM_ACTIVE = 0,
  	RPM_RESUMING,
  	RPM_SUSPENDED,
  	RPM_SUSPENDING,
  };
  
  /*
   * Device run-time power management request types.
   *
   * RPM_REQ_NONE		Do nothing.
   *
   * RPM_REQ_IDLE		Run the device bus type's ->runtime_idle() callback
   *
   * RPM_REQ_SUSPEND	Run the device bus type's ->runtime_suspend() callback
   *
   * RPM_REQ_AUTOSUSPEND	Same as RPM_REQ_SUSPEND, but not until the device has
   *			been inactive for as long as power.autosuspend_delay
   *
   * RPM_REQ_RESUME	Run the device bus type's ->runtime_resume() callback
   */
  
  enum rpm_request {
  	RPM_REQ_NONE = 0,
  	RPM_REQ_IDLE,
  	RPM_REQ_SUSPEND,
  	RPM_REQ_AUTOSUSPEND,
  	RPM_REQ_RESUME,
  };
  
  struct wakeup_source;
  struct wake_irq;
  struct pm_domain_data;
  
  struct pm_subsys_data {
  	spinlock_t lock;
  	unsigned int refcount;
  #ifdef CONFIG_PM_CLK
  	struct list_head clock_list;
  #endif
  #ifdef CONFIG_PM_GENERIC_DOMAINS
  	struct pm_domain_data *domain_data;
  #endif
  };
  
  /*
   * Driver flags to control system suspend/resume behavior.
   *
   * These flags can be set by device drivers at the probe time.  They need not be
   * cleared by the drivers as the driver core will take care of that.
   *
   * NEVER_SKIP: Do not skip all system suspend/resume callbacks for the device.
   * SMART_PREPARE: Check the return value of the driver's ->prepare callback.
   * SMART_SUSPEND: No need to resume the device from runtime suspend.
   * LEAVE_SUSPENDED: Avoid resuming the device during system resume if possible.
   *
   * Setting SMART_PREPARE instructs bus types and PM domains which may want
   * system suspend/resume callbacks to be skipped for the device to return 0 from
   * their ->prepare callbacks if the driver's ->prepare callback returns 0 (in
   * other words, the system suspend/resume callbacks can only be skipped for the
   * device if its driver doesn't object against that).  This flag has no effect
   * if NEVER_SKIP is set.
   *
   * Setting SMART_SUSPEND instructs bus types and PM domains which may want to
   * runtime resume the device upfront during system suspend that doing so is not
   * necessary from the driver's perspective.  It also may cause them to skip
   * invocations of the ->suspend_late and ->suspend_noirq callbacks provided by
   * the driver if they decide to leave the device in runtime suspend.
   *
   * Setting LEAVE_SUSPENDED informs the PM core and middle-layer code that the
   * driver prefers the device to be left in suspend after system resume.
   */
  #define DPM_FLAG_NEVER_SKIP		BIT(0)
  #define DPM_FLAG_SMART_PREPARE		BIT(1)
  #define DPM_FLAG_SMART_SUSPEND		BIT(2)
  #define DPM_FLAG_LEAVE_SUSPENDED	BIT(3)
  
  struct dev_pm_info {
  	pm_message_t		power_state;
  	unsigned int		can_wakeup:1;
  	unsigned int		async_suspend:1;
  	bool			in_dpm_list:1;	/* Owned by the PM core */
  	bool			is_prepared:1;	/* Owned by the PM core */
  	bool			is_suspended:1;	/* Ditto */
  	bool			is_noirq_suspended:1;
  	bool			is_late_suspended:1;
  	bool			no_pm:1;
  	bool			early_init:1;	/* Owned by the PM core */
  	bool			direct_complete:1;	/* Owned by the PM core */
  	u32			driver_flags;
  	spinlock_t		lock;
  #ifdef CONFIG_PM_SLEEP
  	struct list_head	entry;
  	struct completion	completion;
  	struct wakeup_source	*wakeup;
  	bool			wakeup_path:1;
  	bool			syscore:1;
  	bool			no_pm_callbacks:1;	/* Owned by the PM core */
  	unsigned int		must_resume:1;	/* Owned by the PM core */
  	unsigned int		may_skip_resume:1;	/* Set by subsystems */
  #else
  	unsigned int		should_wakeup:1;
  #endif
  #ifdef CONFIG_PM
  	struct hrtimer		suspend_timer;
  	unsigned long		timer_expires;
  	struct work_struct	work;
  	wait_queue_head_t	wait_queue;
  	struct wake_irq		*wakeirq;
  	atomic_t		usage_count;
  	atomic_t		child_count;
  	unsigned int		disable_depth:3;
  	unsigned int		idle_notification:1;
  	unsigned int		request_pending:1;
  	unsigned int		deferred_resume:1;
  	unsigned int		runtime_auto:1;
  	bool			ignore_children:1;
  	unsigned int		no_callbacks:1;
  	unsigned int		irq_safe:1;
  	unsigned int		use_autosuspend:1;
  	unsigned int		timer_autosuspends:1;
  	unsigned int		memalloc_noio:1;
  	unsigned int		links_count;
  	enum rpm_request	request;
  	enum rpm_status		runtime_status;
  	int			runtime_error;
  	int			autosuspend_delay;
  	u64			last_busy;
  	u64			active_time;
  	u64			suspended_time;
  	u64			accounting_timestamp;
  #endif
  	struct pm_subsys_data	*subsys_data;  /* Owned by the subsystem. */
  	void (*set_latency_tolerance)(struct device *, s32);
  	struct dev_pm_qos	*qos;
  };
  
  extern int dev_pm_get_subsys_data(struct device *dev);
  extern void dev_pm_put_subsys_data(struct device *dev);
  
  /**
   * struct dev_pm_domain - power management domain representation.
   *
   * @ops: Power management operations associated with this domain.
   * @detach: Called when removing a device from the domain.
   * @activate: Called before executing probe routines for bus types and drivers.
   * @sync: Called after successful driver probe.
   * @dismiss: Called after unsuccessful driver probe and after driver removal.
   *
   * Power domains provide callbacks that are executed during system suspend,
   * hibernation, system resume and during runtime PM transitions instead of
   * subsystem-level and driver-level callbacks.
   */
  struct dev_pm_domain {
  	struct dev_pm_ops	ops;
  	void (*detach)(struct device *dev, bool power_off);
  	int (*activate)(struct device *dev);
  	void (*sync)(struct device *dev);
  	void (*dismiss)(struct device *dev);
  };
  
  /*
   * The PM_EVENT_ messages are also used by drivers implementing the legacy
   * suspend framework, based on the ->suspend() and ->resume() callbacks common
   * for suspend and hibernation transitions, according to the rules below.
   */
  
  /* Necessary, because several drivers use PM_EVENT_PRETHAW */
  #define PM_EVENT_PRETHAW PM_EVENT_QUIESCE
  
  /*
   * One transition is triggered by resume(), after a suspend() call; the
   * message is implicit:
   *
   * ON		Driver starts working again, responding to hardware events
   *		and software requests.  The hardware may have gone through
   *		a power-off reset, or it may have maintained state from the
   *		previous suspend() which the driver will rely on while
   *		resuming.  On most platforms, there are no restrictions on
   *		availability of resources like clocks during resume().
   *
   * Other transitions are triggered by messages sent using suspend().  All
   * these transitions quiesce the driver, so that I/O queues are inactive.
   * That commonly entails turning off IRQs and DMA; there may be rules
   * about how to quiesce that are specific to the bus or the device's type.
   * (For example, network drivers mark the link state.)  Other details may
   * differ according to the message:
   *
   * SUSPEND	Quiesce, enter a low power device state appropriate for
   *		the upcoming system state (such as PCI_D3hot), and enable
   *		wakeup events as appropriate.
   *
   * HIBERNATE	Enter a low power device state appropriate for the hibernation
   *		state (eg. ACPI S4) and enable wakeup events as appropriate.
   *
   * FREEZE	Quiesce operations so that a consistent image can be saved;
   *		but do NOT otherwise enter a low power device state, and do
   *		NOT emit system wakeup events.
   *
   * PRETHAW	Quiesce as if for FREEZE; additionally, prepare for restoring
   *		the system from a snapshot taken after an earlier FREEZE.
   *		Some drivers will need to reset their hardware state instead
   *		of preserving it, to ensure that it's never mistaken for the
   *		state which that earlier snapshot had set up.
   *
   * A minimally power-aware driver treats all messages as SUSPEND, fully
   * reinitializes its device during resume() -- whether or not it was reset
   * during the suspend/resume cycle -- and can't issue wakeup events.
   *
   * More power-aware drivers may also use low power states at runtime as
   * well as during system sleep states like PM_SUSPEND_STANDBY.  They may
   * be able to use wakeup events to exit from runtime low-power states,
   * or from system low-power states such as standby or suspend-to-RAM.
   */
  
  #ifdef CONFIG_PM_SLEEP
  extern void device_pm_lock(void);
  extern void dpm_resume_start(pm_message_t state);
  extern void dpm_resume_end(pm_message_t state);
  extern void dpm_noirq_resume_devices(pm_message_t state);
  extern void dpm_noirq_end(void);
  extern void dpm_resume_noirq(pm_message_t state);
  extern void dpm_resume_early(pm_message_t state);
  extern void dpm_resume(pm_message_t state);
  extern void dpm_complete(pm_message_t state);
  
  extern void device_pm_unlock(void);
  extern int dpm_suspend_end(pm_message_t state);
  extern int dpm_suspend_start(pm_message_t state);
  extern void dpm_noirq_begin(void);
  extern int dpm_noirq_suspend_devices(pm_message_t state);
  extern int dpm_suspend_noirq(pm_message_t state);
  extern int dpm_suspend_late(pm_message_t state);
  extern int dpm_suspend(pm_message_t state);
  extern int dpm_prepare(pm_message_t state);
  
  extern void __suspend_report_result(const char *function, void *fn, int ret);
  
  #define suspend_report_result(fn, ret)					\
  	do {								\
  		__suspend_report_result(__func__, fn, ret);		\
  	} while (0)
  
  extern int device_pm_wait_for_dev(struct device *sub, struct device *dev);
  extern void dpm_for_each_dev(void *data, void (*fn)(struct device *, void *));
  
  extern int pm_generic_prepare(struct device *dev);
  extern int pm_generic_suspend_late(struct device *dev);
  extern int pm_generic_suspend_noirq(struct device *dev);
  extern int pm_generic_suspend(struct device *dev);
  extern int pm_generic_resume_early(struct device *dev);
  extern int pm_generic_resume_noirq(struct device *dev);
  extern int pm_generic_resume(struct device *dev);
  extern int pm_generic_freeze_noirq(struct device *dev);
  extern int pm_generic_freeze_late(struct device *dev);
  extern int pm_generic_freeze(struct device *dev);
  extern int pm_generic_thaw_noirq(struct device *dev);
  extern int pm_generic_thaw_early(struct device *dev);
  extern int pm_generic_thaw(struct device *dev);
  extern int pm_generic_restore_noirq(struct device *dev);
  extern int pm_generic_restore_early(struct device *dev);
  extern int pm_generic_restore(struct device *dev);
  extern int pm_generic_poweroff_noirq(struct device *dev);
  extern int pm_generic_poweroff_late(struct device *dev);
  extern int pm_generic_poweroff(struct device *dev);
  extern void pm_generic_complete(struct device *dev);
  
  extern void dev_pm_skip_next_resume_phases(struct device *dev);
  extern bool dev_pm_may_skip_resume(struct device *dev);
  extern bool dev_pm_smart_suspend_and_suspended(struct device *dev);
  
  #else /* !CONFIG_PM_SLEEP */
  
  #define device_pm_lock() do {} while (0)
  #define device_pm_unlock() do {} while (0)
  
  static inline int dpm_suspend_start(pm_message_t state)
  {
  	return 0;
  }
  
  #define suspend_report_result(fn, ret)		do {} while (0)
  
  static inline int device_pm_wait_for_dev(struct device *a, struct device *b)
  {
  	return 0;
  }
  
  static inline void dpm_for_each_dev(void *data, void (*fn)(struct device *, void *))
  {
  }
  
  #define pm_generic_prepare		NULL
  #define pm_generic_suspend_late		NULL
  #define pm_generic_suspend_noirq	NULL
  #define pm_generic_suspend		NULL
  #define pm_generic_resume_early		NULL
  #define pm_generic_resume_noirq		NULL
  #define pm_generic_resume		NULL
  #define pm_generic_freeze_noirq		NULL
  #define pm_generic_freeze_late		NULL
  #define pm_generic_freeze		NULL
  #define pm_generic_thaw_noirq		NULL
  #define pm_generic_thaw_early		NULL
  #define pm_generic_thaw			NULL
  #define pm_generic_restore_noirq	NULL
  #define pm_generic_restore_early	NULL
  #define pm_generic_restore		NULL
  #define pm_generic_poweroff_noirq	NULL
  #define pm_generic_poweroff_late	NULL
  #define pm_generic_poweroff		NULL
  #define pm_generic_complete		NULL
  #endif /* !CONFIG_PM_SLEEP */
  
  /* How to reorder dpm_list after device_move() */
  enum dpm_order {
  	DPM_ORDER_NONE,
  	DPM_ORDER_DEV_AFTER_PARENT,
  	DPM_ORDER_PARENT_BEFORE_DEV,
  	DPM_ORDER_DEV_LAST,
  };
  
  #endif /* _LINUX_PM_H */
  