LCOV - code coverage report
Current view: top level - klever-core-work-dir/0d4a846/linux-drivers-clk2/lkbce/include/linux - pm.h (source / functions) Hit Total Coverage
Test: coverage.info Lines: 5 5 100.0 %
Date: 2017-01-25 Functions: 0 0 -

          Line data    Source code
       1             : /*
       2             :  *  pm.h - Power management interface
       3             :  *
       4             :  *  Copyright (C) 2000 Andrew Henroid
       5             :  *
       6             :  *  This program is free software; you can redistribute it and/or modify
       7             :  *  it under the terms of the GNU General Public License as published by
       8             :  *  the Free Software Foundation; either version 2 of the License, or
       9             :  *  (at your option) any later version.
      10             :  *
      11             :  *  This program is distributed in the hope that it will be useful,
      12             :  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
      13             :  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      14             :  *  GNU General Public License for more details.
      15             :  *
      16             :  *  You should have received a copy of the GNU General Public License
      17             :  *  along with this program; if not, write to the Free Software
      18             :  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
      19             :  */
      20             : 
      21             : #ifndef _LINUX_PM_H
      22             : #define _LINUX_PM_H
      23             : 
      24             : #include <linux/list.h>
      25             : #include <linux/workqueue.h>
      26             : #include <linux/spinlock.h>
      27             : #include <linux/wait.h>
      28             : #include <linux/timer.h>
      29             : 
      30             : /*
      31             :  * Callbacks for platform drivers to implement.
      32             :  */
      33             : extern void (*pm_idle)(void);
      34             : extern void (*pm_power_off)(void);
      35             : extern void (*pm_power_off_prepare)(void);
      36           1 : 
      37             : /*
      38             :  * Device power management
      39             :  */
      40             : 
      41             : struct device;
      42             : 
      43             : typedef struct pm_message {
      44             :         int event;
      45           1 : } pm_message_t;
      46           1 : 
      47             : /**
      48             :  * struct dev_pm_ops - device PM callbacks
      49             :  *
      50             :  * Several driver power state transitions are externally visible, affecting
      51             :  * the state of pending I/O queues and (for drivers that touch hardware)
      52             :  * interrupts, wakeups, DMA, and other hardware state.  There may also be
      53             :  * internal transitions to various low power modes, which are transparent
      54             :  * to the rest of the driver stack (such as a driver that's ON gating off
      55             :  * clocks which are not in active use).
      56             :  *
      57             :  * The externally visible transitions are handled with the help of the following
      58             :  * callbacks included in this structure:
      59             :  *
      60             :  * @prepare: Prepare the device for the upcoming transition, but do NOT change
      61             :  *      its hardware state.  Prevent new children of the device from being
      62             :  *      registered after @prepare() returns (the driver's subsystem and
      63             :  *      generally the rest of the kernel is supposed to prevent new calls to the
      64             :  *      probe method from being made too once @prepare() has succeeded).  If
      65             :  *      @prepare() detects a situation it cannot handle (e.g. registration of a
      66             :  *      child already in progress), it may return -EAGAIN, so that the PM core
      67             :  *      can execute it once again (e.g. after the new child has been registered)
      68             :  *      to recover from the race condition.  This method is executed for all
      69             :  *      kinds of suspend transitions and is followed by one of the suspend
      70             :  *      callbacks: @suspend(), @freeze(), or @poweroff().
      71             :  *      The PM core executes @prepare() for all devices before starting to
      72             :  *      execute suspend callbacks for any of them, so drivers may assume all of
      73             :  *      the other devices to be present and functional while @prepare() is being
      74             :  *      executed.  In particular, it is safe to make GFP_KERNEL memory
      75             :  *      allocations from within @prepare().  However, drivers may NOT assume
      76             :  *      anything about the availability of the user space at that time and it
      77             :  *      is not correct to request firmware from within @prepare() (it's too
      78             :  *      late to do that).  [To work around this limitation, drivers may
      79             :  *      register suspend and hibernation notifiers that are executed before the
      80             :  *      freezing of tasks.]
      81             :  *
      82             :  * @complete: Undo the changes made by @prepare().  This method is executed for
      83             :  *      all kinds of resume transitions, following one of the resume callbacks:
      84             :  *      @resume(), @thaw(), @restore().  Also called if the state transition
      85             :  *      fails before the driver's suspend callback (@suspend(), @freeze(),
      86             :  *      @poweroff()) can be executed (e.g. if the suspend callback fails for one
      87             :  *      of the other devices that the PM core has unsuccessfully attempted to
      88             :  *      suspend earlier).
      89             :  *      The PM core executes @complete() after it has executed the appropriate
      90             :  *      resume callback for all devices.
      91             :  *
      92             :  * @suspend: Executed before putting the system into a sleep state in which the
      93             :  *      contents of main memory are preserved.  Quiesce the device, put it into
      94             :  *      a low power state appropriate for the upcoming system state (such as
      95             :  *      PCI_D3hot), and enable wakeup events as appropriate.
      96             :  *
      97             :  * @resume: Executed after waking the system up from a sleep state in which the
      98             :  *      contents of main memory were preserved.  Put the device into the
      99             :  *      appropriate state, according to the information saved in memory by the
     100             :  *      preceding @suspend().  The driver starts working again, responding to
     101             :  *      hardware events and software requests.  The hardware may have gone
     102             :  *      through a power-off reset, or it may have maintained state from the
     103             :  *      previous suspend() which the driver may rely on while resuming.  On most
     104             :  *      platforms, there are no restrictions on availability of resources like
     105             :  *      clocks during @resume().
     106             :  *
     107             :  * @freeze: Hibernation-specific, executed before creating a hibernation image.
     108             :  *      Quiesce operations so that a consistent image can be created, but do NOT
     109             :  *      otherwise put the device into a low power device state and do NOT emit
     110             :  *      system wakeup events.  Save in main memory the device settings to be
     111             :  *      used by @restore() during the subsequent resume from hibernation or by
     112             :  *      the subsequent @thaw(), if the creation of the image or the restoration
     113             :  *      of main memory contents from it fails.
     114             :  *
     115             :  * @thaw: Hibernation-specific, executed after creating a hibernation image OR
     116             :  *      if the creation of the image fails.  Also executed after a failing
     117             :  *      attempt to restore the contents of main memory from such an image.
     118             :  *      Undo the changes made by the preceding @freeze(), so the device can be
     119             :  *      operated in the same way as immediately before the call to @freeze().
     120             :  *
     121             :  * @poweroff: Hibernation-specific, executed after saving a hibernation image.
     122             :  *      Quiesce the device, put it into a low power state appropriate for the
     123             :  *      upcoming system state (such as PCI_D3hot), and enable wakeup events as
     124             :  *      appropriate.
     125             :  *
     126             :  * @restore: Hibernation-specific, executed after restoring the contents of main
     127             :  *      memory from a hibernation image.  Driver starts working again,
     128             :  *      responding to hardware events and software requests.  Drivers may NOT
     129             :  *      make ANY assumptions about the hardware state right prior to @restore().
     130             :  *      On most platforms, there are no restrictions on availability of
     131             :  *      resources like clocks during @restore().
     132             :  *
     133             :  * @suspend_noirq: Complete the operations of ->suspend() by carrying out any
     134             :  *      actions required for suspending the device that need interrupts to be
     135             :  *      disabled
     136             :  *
     137             :  * @resume_noirq: Prepare for the execution of ->resume() by carrying out any
     138             :  *      actions required for resuming the device that need interrupts to be
     139             :  *      disabled
     140             :  *
     141             :  * @freeze_noirq: Complete the operations of ->freeze() by carrying out any
     142             :  *      actions required for freezing the device that need interrupts to be
     143             :  *      disabled
     144             :  *
     145             :  * @thaw_noirq: Prepare for the execution of ->thaw() by carrying out any
     146             :  *      actions required for thawing the device that need interrupts to be
     147             :  *      disabled
     148             :  *
     149             :  * @poweroff_noirq: Complete the operations of ->poweroff() by carrying out any
     150             :  *      actions required for handling the device that need interrupts to be
     151             :  *      disabled
     152             :  *
     153             :  * @restore_noirq: Prepare for the execution of ->restore() by carrying out any
     154             :  *      actions required for restoring the operations of the device that need
     155             :  *      interrupts to be disabled
     156             :  *
     157             :  * All of the above callbacks, except for @complete(), return error codes.
     158             :  * However, the error codes returned by the resume operations, @resume(),
     159             :  * @thaw(), @restore(), @resume_noirq(), @thaw_noirq(), and @restore_noirq() do
     160             :  * not cause the PM core to abort the resume transition during which they are
     161             :  * returned.  The error codes returned in that cases are only printed by the PM
     162             :  * core to the system logs for debugging purposes.  Still, it is recommended
     163             :  * that drivers only return error codes from their resume methods in case of an
     164             :  * unrecoverable failure (i.e. when the device being handled refuses to resume
     165             :  * and becomes unusable) to allow us to modify the PM core in the future, so
     166             :  * that it can avoid attempting to handle devices that failed to resume and
     167             :  * their children.
     168             :  *
     169             :  * It is allowed to unregister devices while the above callbacks are being
     170             :  * executed.  However, it is not allowed to unregister a device from within any
     171             :  * of its own callbacks.
     172             :  *
     173             :  * There also are the following callbacks related to run-time power management
     174             :  * of devices:
     175             :  *
     176             :  * @runtime_suspend: Prepare the device for a condition in which it won't be
     177             :  *      able to communicate with the CPU(s) and RAM due to power management.
     178             :  *      This need not mean that the device should be put into a low power state.
     179             :  *      For example, if the device is behind a link which is about to be turned
     180             :  *      off, the device may remain at full power.  If the device does go to low
     181             :  *      power and is capable of generating run-time wake-up events, remote
     182             :  *      wake-up (i.e., a hardware mechanism allowing the device to request a
     183             :  *      change of its power state via a wake-up event, such as PCI PME) should
     184             :  *      be enabled for it.
     185             :  *
     186             :  * @runtime_resume: Put the device into the fully active state in response to a
     187             :  *      wake-up event generated by hardware or at the request of software.  If
     188             :  *      necessary, put the device into the full power state and restore its
     189             :  *      registers, so that it is fully operational.
     190             :  *
     191             :  * @runtime_idle: Device appears to be inactive and it might be put into a low
     192             :  *      power state if all of the necessary conditions are satisfied.  Check
     193             :  *      these conditions and handle the device as appropriate, possibly queueing
     194             :  *      a suspend request for it.  The return value is ignored by the PM core.
     195             :  */
     196             : 
     197             : struct dev_pm_ops {
     198             :         int (*prepare)(struct device *dev);
     199             :         void (*complete)(struct device *dev);
     200             :         int (*suspend)(struct device *dev);
     201             :         int (*resume)(struct device *dev);
     202             :         int (*freeze)(struct device *dev);
     203             :         int (*thaw)(struct device *dev);
     204             :         int (*poweroff)(struct device *dev);
     205             :         int (*restore)(struct device *dev);
     206             :         int (*suspend_noirq)(struct device *dev);
     207             :         int (*resume_noirq)(struct device *dev);
     208             :         int (*freeze_noirq)(struct device *dev);
     209             :         int (*thaw_noirq)(struct device *dev);
     210             :         int (*poweroff_noirq)(struct device *dev);
     211             :         int (*restore_noirq)(struct device *dev);
     212             :         int (*runtime_suspend)(struct device *dev);
     213             :         int (*runtime_resume)(struct device *dev);
     214             :         int (*runtime_idle)(struct device *dev);
     215             : };
     216           1 : 
     217             : /*
     218             :  * Use this if you want to use the same suspend and resume callbacks for suspend
     219             :  * to RAM and hibernation.
     220             :  */
     221             : #define SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn) \
     222             : const struct dev_pm_ops name = { \
     223             :         .suspend = suspend_fn, \
     224             :         .resume = resume_fn, \
     225             :         .freeze = suspend_fn, \
     226             :         .thaw = resume_fn, \
     227             :         .poweroff = suspend_fn, \
     228             :         .restore = resume_fn, \
     229             : }
     230             : 
     231             : /**
     232             :  * PM_EVENT_ messages
     233             :  *
     234             :  * The following PM_EVENT_ messages are defined for the internal use of the PM
     235             :  * core, in order to provide a mechanism allowing the high level suspend and
     236             :  * hibernation code to convey the necessary information to the device PM core
     237             :  * code:
     238             :  *
     239             :  * ON           No transition.
     240           1 :  *
     241             :  * FREEZE       System is going to hibernate, call ->prepare() and ->freeze()
     242             :  *              for all devices.
     243             :  *
     244             :  * SUSPEND      System is going to suspend, call ->prepare() and ->suspend()
     245             :  *              for all devices.
     246             :  *
     247             :  * HIBERNATE    Hibernation image has been saved, call ->prepare() and
     248             :  *              ->poweroff() for all devices.
     249             :  *
     250             :  * QUIESCE      Contents of main memory are going to be restored from a (loaded)
     251             :  *              hibernation image, call ->prepare() and ->freeze() for all
     252             :  *              devices.
     253             :  *
     254             :  * RESUME       System is resuming, call ->resume() and ->complete() for all
     255             :  *              devices.
     256             :  *
     257             :  * THAW         Hibernation image has been created, call ->thaw() and
     258             :  *              ->complete() for all devices.
     259             :  *
     260             :  * RESTORE      Contents of main memory have been restored from a hibernation
     261             :  *              image, call ->restore() and ->complete() for all devices.
     262             :  *
     263             :  * RECOVER      Creation of a hibernation image or restoration of the main
     264             :  *              memory contents from a hibernation image has failed, call
     265             :  *              ->thaw() and ->complete() for all devices.
     266             :  *
     267             :  * The following PM_EVENT_ messages are defined for internal use by
     268             :  * kernel subsystems.  They are never issued by the PM core.
     269             :  *
     270             :  * USER_SUSPEND         Manual selective suspend was issued by userspace.
     271             :  *
     272             :  * USER_RESUME          Manual selective resume was issued by userspace.
     273             :  *
     274             :  * REMOTE_WAKEUP        Remote-wakeup request was received from the device.
     275             :  *
     276             :  * AUTO_SUSPEND         Automatic (device idle) runtime suspend was
     277             :  *                      initiated by the subsystem.
     278             :  *
     279             :  * AUTO_RESUME          Automatic (device needed) runtime resume was
     280             :  *                      requested by a driver.
     281             :  */
     282             : 
     283             : #define PM_EVENT_ON             0x0000
     284             : #define PM_EVENT_FREEZE         0x0001
     285             : #define PM_EVENT_SUSPEND        0x0002
     286             : #define PM_EVENT_HIBERNATE      0x0004
     287             : #define PM_EVENT_QUIESCE        0x0008
     288             : #define PM_EVENT_RESUME         0x0010
     289             : #define PM_EVENT_THAW           0x0020
     290             : #define PM_EVENT_RESTORE        0x0040
     291             : #define PM_EVENT_RECOVER        0x0080
     292             : #define PM_EVENT_USER           0x0100
     293             : #define PM_EVENT_REMOTE         0x0200
     294             : #define PM_EVENT_AUTO           0x0400
     295             : 
     296             : #define PM_EVENT_SLEEP          (PM_EVENT_SUSPEND | PM_EVENT_HIBERNATE)
     297             : #define PM_EVENT_USER_SUSPEND   (PM_EVENT_USER | PM_EVENT_SUSPEND)
     298             : #define PM_EVENT_USER_RESUME    (PM_EVENT_USER | PM_EVENT_RESUME)
     299             : #define PM_EVENT_REMOTE_RESUME  (PM_EVENT_REMOTE | PM_EVENT_RESUME)
     300             : #define PM_EVENT_AUTO_SUSPEND   (PM_EVENT_AUTO | PM_EVENT_SUSPEND)
     301             : #define PM_EVENT_AUTO_RESUME    (PM_EVENT_AUTO | PM_EVENT_RESUME)
     302             : 
     303             : #define PMSG_ON         ((struct pm_message){ .event = PM_EVENT_ON, })
     304             : #define PMSG_FREEZE     ((struct pm_message){ .event = PM_EVENT_FREEZE, })
     305             : #define PMSG_QUIESCE    ((struct pm_message){ .event = PM_EVENT_QUIESCE, })
     306             : #define PMSG_SUSPEND    ((struct pm_message){ .event = PM_EVENT_SUSPEND, })
     307             : #define PMSG_HIBERNATE  ((struct pm_message){ .event = PM_EVENT_HIBERNATE, })
     308             : #define PMSG_RESUME     ((struct pm_message){ .event = PM_EVENT_RESUME, })
     309             : #define PMSG_THAW       ((struct pm_message){ .event = PM_EVENT_THAW, })
     310             : #define PMSG_RESTORE    ((struct pm_message){ .event = PM_EVENT_RESTORE, })
     311             : #define PMSG_RECOVER    ((struct pm_message){ .event = PM_EVENT_RECOVER, })
     312             : #define PMSG_USER_SUSPEND       ((struct pm_message) \
     313             :                                         { .event = PM_EVENT_USER_SUSPEND, })
     314             : #define PMSG_USER_RESUME        ((struct pm_message) \
     315             :                                         { .event = PM_EVENT_USER_RESUME, })
     316             : #define PMSG_REMOTE_RESUME      ((struct pm_message) \
     317             :                                         { .event = PM_EVENT_REMOTE_RESUME, })
     318             : #define PMSG_AUTO_SUSPEND       ((struct pm_message) \
     319             :                                         { .event = PM_EVENT_AUTO_SUSPEND, })
     320             : #define PMSG_AUTO_RESUME        ((struct pm_message) \
     321             :                                         { .event = PM_EVENT_AUTO_RESUME, })
     322             : 
     323             : /**
     324             :  * Device power management states
     325             :  *
     326             :  * These state labels are used internally by the PM core to indicate the current
     327             :  * status of a device with respect to the PM core operations.
     328             :  *
     329             :  * DPM_ON               Device is regarded as operational.  Set this way
     330             :  *                      initially and when ->complete() is about to be called.
     331             :  *                      Also set when ->prepare() fails.
     332             :  *
     333             :  * DPM_PREPARING        Device is going to be prepared for a PM transition.  Set
     334             :  *                      when ->prepare() is about to be called.
     335             :  *
     336             :  * DPM_RESUMING         Device is going to be resumed.  Set when ->resume(),
     337             :  *                      ->thaw(), or ->restore() is about to be called.
     338             :  *
     339             :  * DPM_SUSPENDING       Device has been prepared for a power transition.  Set
     340             :  *                      when ->prepare() has just succeeded.
     341             :  *
     342             :  * DPM_OFF              Device is regarded as inactive.  Set immediately after
     343             :  *                      ->suspend(), ->freeze(), or ->poweroff() has succeeded.
     344             :  *                      Also set when ->resume()_noirq, ->thaw_noirq(), or
     345             :  *                      ->restore_noirq() is about to be called.
     346             :  *
     347             :  * DPM_OFF_IRQ          Device is in a "deep sleep".  Set immediately after
     348             :  *                      ->suspend_noirq(), ->freeze_noirq(), or
     349             :  *                      ->poweroff_noirq() has just succeeded.
     350             :  */
     351             : 
     352             : enum dpm_state {
     353             :         DPM_INVALID,
     354             :         DPM_ON,
     355             :         DPM_PREPARING,
     356             :         DPM_RESUMING,
     357             :         DPM_SUSPENDING,
     358             :         DPM_OFF,
     359             :         DPM_OFF_IRQ,
     360             : };
     361             : 
     362             : /**
     363             :  * Device run-time power management status.
     364             :  *
     365             :  * These status labels are used internally by the PM core to indicate the
     366             :  * current status of a device with respect to the PM core operations.  They do
     367             :  * not reflect the actual power state of the device or its status as seen by the
     368             :  * driver.
     369             :  *
     370             :  * RPM_ACTIVE           Device is fully operational.  Indicates that the device
     371             :  *                      bus type's ->runtime_resume() callback has completed
     372             :  *                      successfully.
     373             :  *
     374             :  * RPM_SUSPENDED        Device bus type's ->runtime_suspend() callback has
     375             :  *                      completed successfully.  The device is regarded as
     376             :  *                      suspended.
     377             :  *
     378             :  * RPM_RESUMING         Device bus type's ->runtime_resume() callback is being
     379             :  *                      executed.
     380             :  *
     381             :  * RPM_SUSPENDING       Device bus type's ->runtime_suspend() callback is being
     382             :  *                      executed.
     383             :  */
     384             : 
     385             : enum rpm_status {
     386             :         RPM_ACTIVE = 0,
     387             :         RPM_RESUMING,
     388             :         RPM_SUSPENDED,
     389             :         RPM_SUSPENDING,
     390             : };
     391             : 
     392             : /**
     393             :  * Device run-time power management request types.
     394             :  *
     395             :  * RPM_REQ_NONE         Do nothing.
     396             :  *
     397             :  * RPM_REQ_IDLE         Run the device bus type's ->runtime_idle() callback
     398             :  *
     399             :  * RPM_REQ_SUSPEND      Run the device bus type's ->runtime_suspend() callback
     400             :  *
     401             :  * RPM_REQ_RESUME       Run the device bus type's ->runtime_resume() callback
     402             :  */
     403             : 
     404             : enum rpm_request {
     405             :         RPM_REQ_NONE = 0,
     406             :         RPM_REQ_IDLE,
     407             :         RPM_REQ_SUSPEND,
     408             :         RPM_REQ_RESUME,
     409             : };
     410             : 
     411             : struct dev_pm_info {
     412             :         pm_message_t            power_state;
     413             :         unsigned int            can_wakeup:1;
     414             :         unsigned int            should_wakeup:1;
     415             :         enum dpm_state          status;         /* Owned by the PM core */
     416             : #ifdef CONFIG_PM_SLEEP
     417             :         struct list_head        entry;
     418             : #endif
     419             : #ifdef CONFIG_PM_RUNTIME
     420             :         struct timer_list       suspend_timer;
     421             :         unsigned long           timer_expires;
     422             :         struct work_struct      work;
     423             :         wait_queue_head_t       wait_queue;
     424             :         spinlock_t              lock;
     425             :         atomic_t                usage_count;
     426             :         atomic_t                child_count;
     427             :         unsigned int            disable_depth:3;
     428             :         unsigned int            ignore_children:1;
     429             :         unsigned int            idle_notification:1;
     430             :         unsigned int            request_pending:1;
     431             :         unsigned int            deferred_resume:1;
     432             :         unsigned int            run_wake:1;
     433             :         enum rpm_request        request;
     434             :         enum rpm_status         runtime_status;
     435             :         int                     runtime_error;
     436             : #endif
     437             : };
     438             : 
     439             : /*
     440             :  * The PM_EVENT_ messages are also used by drivers implementing the legacy
     441             :  * suspend framework, based on the ->suspend() and ->resume() callbacks common
     442             :  * for suspend and hibernation transitions, according to the rules below.
     443             :  */
     444             : 
     445             : /* Necessary, because several drivers use PM_EVENT_PRETHAW */
     446             : #define PM_EVENT_PRETHAW PM_EVENT_QUIESCE
     447             : 
     448             : /*
     449             :  * One transition is triggered by resume(), after a suspend() call; the
     450             :  * message is implicit:
     451             :  *
     452             :  * ON           Driver starts working again, responding to hardware events
     453             :  *              and software requests.  The hardware may have gone through
     454             :  *              a power-off reset, or it may have maintained state from the
     455             :  *              previous suspend() which the driver will rely on while
     456             :  *              resuming.  On most platforms, there are no restrictions on
     457             :  *              availability of resources like clocks during resume().
     458             :  *
     459             :  * Other transitions are triggered by messages sent using suspend().  All
     460             :  * these transitions quiesce the driver, so that I/O queues are inactive.
     461             :  * That commonly entails turning off IRQs and DMA; there may be rules
     462             :  * about how to quiesce that are specific to the bus or the device's type.
     463             :  * (For example, network drivers mark the link state.)  Other details may
     464             :  * differ according to the message:
     465             :  *
     466             :  * SUSPEND      Quiesce, enter a low power device state appropriate for
     467             :  *              the upcoming system state (such as PCI_D3hot), and enable
     468             :  *              wakeup events as appropriate.
     469             :  *
     470             :  * HIBERNATE    Enter a low power device state appropriate for the hibernation
     471             :  *              state (eg. ACPI S4) and enable wakeup events as appropriate.
     472             :  *
     473             :  * FREEZE       Quiesce operations so that a consistent image can be saved;
     474             :  *              but do NOT otherwise enter a low power device state, and do
     475             :  *              NOT emit system wakeup events.
     476             :  *
     477             :  * PRETHAW      Quiesce as if for FREEZE; additionally, prepare for restoring
     478             :  *              the system from a snapshot taken after an earlier FREEZE.
     479             :  *              Some drivers will need to reset their hardware state instead
     480             :  *              of preserving it, to ensure that it's never mistaken for the
     481             :  *              state which that earlier snapshot had set up.
     482             :  *
     483             :  * A minimally power-aware driver treats all messages as SUSPEND, fully
     484             :  * reinitializes its device during resume() -- whether or not it was reset
     485             :  * during the suspend/resume cycle -- and can't issue wakeup events.
     486             :  *
     487             :  * More power-aware drivers may also use low power states at runtime as
     488             :  * well as during system sleep states like PM_SUSPEND_STANDBY.  They may
     489             :  * be able to use wakeup events to exit from runtime low-power states,
     490             :  * or from system low-power states such as standby or suspend-to-RAM.
     491             :  */
     492             : 
     493             : #ifdef CONFIG_PM_SLEEP
     494             : extern void device_pm_lock(void);
     495             : extern int sysdev_resume(void);
     496             : extern void dpm_resume_noirq(pm_message_t state);
     497             : extern void dpm_resume_end(pm_message_t state);
     498             : 
     499             : extern void device_pm_unlock(void);
     500             : extern int sysdev_suspend(pm_message_t state);
     501             : extern int dpm_suspend_noirq(pm_message_t state);
     502             : extern int dpm_suspend_start(pm_message_t state);
     503             : 
     504             : extern void __suspend_report_result(const char *function, void *fn, int ret);
     505             : 
     506             : #define suspend_report_result(fn, ret)                                  \
     507             :         do {                                                            \
     508             :                 __suspend_report_result(__func__, fn, ret);             \
     509             :         } while (0)
     510             : 
     511             : #else /* !CONFIG_PM_SLEEP */
     512             : 
     513             : #define device_pm_lock() do {} while (0)
     514             : #define device_pm_unlock() do {} while (0)
     515             : 
     516             : static inline int dpm_suspend_start(pm_message_t state)
     517             : {
     518             :         return 0;
     519             : }
     520             : 
     521             : #define suspend_report_result(fn, ret)          do {} while (0)
     522             : 
     523             : #endif /* !CONFIG_PM_SLEEP */
     524             : 
     525             : /* How to reorder dpm_list after device_move() */
     526             : enum dpm_order {
     527             :         DPM_ORDER_NONE,
     528             :         DPM_ORDER_DEV_AFTER_PARENT,
     529             :         DPM_ORDER_PARENT_BEFORE_DEV,
     530             :         DPM_ORDER_DEV_LAST,
     531             : };
     532             : 
     533             : /*
     534             :  * Global Power Management flags
     535             :  * Used to keep APM and ACPI from both being active
     536             :  */
     537             : extern unsigned int     pm_flags;
     538             : 
     539             : #define PM_APM  1
     540             : #define PM_ACPI 2
     541             : 
     542             : #endif /* _LINUX_PM_H */

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