xnu-344.21.73.tar.gz

[apple/xnu.git] / iokit / Drivers / platform / drvAppleRootDomain / RootDomain.cpp

   /*
 * Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
#include <IOKit/IOWorkLoop.h>
#include <IOKit/IOCommandGate.h>
#include <IOKit/IOTimerEventSource.h>
#include <IOKit/IOPlatformExpert.h>
#include <IOKit/IOKitDebug.h>
#include <IOKit/IOTimeStamp.h>
#include <IOKit/pwr_mgt/RootDomain.h>
#include <IOKit/pwr_mgt/IOPMPrivate.h>
#include <IOKit/IOMessage.h>
#include "RootDomainUserClient.h"
#include "IOKit/pwr_mgt/IOPowerConnection.h"

extern "C" void kprintf(const char *, ...);

extern const IORegistryPlane * gIOPowerPlane;

// debug trace function
static inline void
ioSPMTrace(unsigned int csc,
	   unsigned int a = 0, unsigned int b = 0,
	   unsigned int c = 0, unsigned int d = 0)
{
    if (gIOKitDebug & kIOLogTracePower)
	IOTimeStampConstant(IODBG_POWER(csc), a, b, c, d);
}

IOReturn broadcast_aggressiveness ( OSObject *, void *, void *, void *, void * );
static void sleepTimerExpired(thread_call_param_t);
static void wakeupClamshellTimerExpired ( thread_call_param_t us);


#define number_of_power_states 5
#define OFF_STATE 0
#define RESTART_STATE 1
#define SLEEP_STATE 2
#define DOZE_STATE 3
#define ON_STATE 4

#define ON_POWER kIOPMPowerOn
#define RESTART_POWER kIOPMRestart
#define SLEEP_POWER kIOPMAuxPowerOn
#define DOZE_POWER kIOPMDoze

static IOPMPowerState ourPowerStates[number_of_power_states] = {
    {1,0,			0,		0,0,0,0,0,0,0,0,0},		// state 0, off
    {1,kIOPMRestartCapability,	kIOPMRestart,	RESTART_POWER,0,0,0,0,0,0,0,0},	// state 1, restart
    {1,kIOPMSleepCapability,	kIOPMSleep,	SLEEP_POWER,0,0,0,0,0,0,0,0},	// state 2, sleep
    {1,kIOPMDoze,		kIOPMDoze,	DOZE_POWER,0,0,0,0,0,0,0,0},	// state 3, doze
    {1,kIOPMPowerOn,		kIOPMPowerOn,	ON_POWER,0,0,0,0,0,0,0,0},	// state 4, on
};

static IOPMrootDomain * gRootDomain;
static UInt32           gSleepOrShutdownPending = 0;


#define super IOService
OSDefineMetaClassAndStructors(IOPMrootDomain,IOService)

extern "C"
{
    IONotifier * registerSleepWakeInterest(IOServiceInterestHandler handler, void * self, void * ref = 0)
    {
        return gRootDomain->registerInterest( gIOGeneralInterest, handler, self, ref );
    }

    IONotifier * registerPrioritySleepWakeInterest(IOServiceInterestHandler handler, void * self, void * ref = 0)
    {
        return gRootDomain->registerInterest( gIOPriorityPowerStateInterest, handler, self, ref );
    }

    IOReturn acknowledgeSleepWakeNotification(void * PMrefcon)
    {
        return gRootDomain->allowPowerChange ( (unsigned long)PMrefcon );
    }

    IOReturn vetoSleepWakeNotification(void * PMrefcon)
    {
        return gRootDomain->cancelPowerChange ( (unsigned long)PMrefcon );
    }
    
    IOReturn rootDomainRestart ( void )
    {
        return gRootDomain->restartSystem();
    }
    
    IOReturn rootDomainShutdown ( void )
    {
        return gRootDomain->shutdownSystem();
    }

	void IOSystemShutdownNotification ( void )
    {
        for ( int i = 0; i < 100; i++ )
        {
            if ( OSCompareAndSwap( 0, 1, &gSleepOrShutdownPending ) ) break;
            IOSleep( 100 );
        }
    }

    int sync_internal(void);    
}

/*
A device is always in the highest power state which satisfies its driver, its policy-maker, and any power domain
children it has, but within the constraint of the power state provided by its parent.  The driver expresses its desire by
calling changePowerStateTo(), the policy-maker expresses its desire by calling changePowerStateToPriv(), and the children
express their desires by calling requestPowerDomainState().

The Root Power Domain owns the policy for idle and demand sleep and doze for the system.  It is a power-managed IOService just
like the others in the system.  It implements several power states which correspond to what we see as Sleep, Doze, etc.

The sleep/doze policy is as follows:
Sleep and Doze are prevented if the case is open so that nobody will think the machine is off and plug/unplug cards.
Sleep and Doze are prevented if the sleep timeout slider in the preferences panel is at zero.
The system cannot Sleep, but can Doze if some object in the tree is in a power state marked kIOPMPreventSystemSleep.

These three conditions are enforced using the "driver clamp" by calling changePowerStateTo().  For example, if the case is
opened, changePowerStateTo(ON_STATE) is called to hold the system on regardless of the desires of the children of the root or
the state of the other clamp.

Demand Sleep/Doze is initiated by pressing the front panel power button, closing the clamshell, or selecting the menu item.
In this case the root's parent actually initiates the power state change so that the root has no choice and does not give
applications the opportunity to veto the change.

Idle Sleep/Doze occurs if no objects in the tree are in a state marked kIOPMPreventIdleSleep.  When this is true, the root's
children are not holding the root on, so it sets the "policy-maker clamp" by calling changePowerStateToPriv(ON_STATE)
to hold itself on until the sleep timer expires.  This timer is set for the difference between the sleep timeout slider and
the larger of the display dim timeout slider and the disk spindown timeout slider in the Preferences panel.  For example, if
the system is set to sleep after thirty idle minutes, and the display and disk are set to sleep after five idle minutes,
when there is no longer an object in the tree holding the system out of Idle Sleep (via kIOPMPreventIdleSleep), the root
sets its timer for 25 minutes (30 - 5).  When the timer expires, it releases its clamp and now nothing is holding it awake,
so it falls asleep.

Demand sleep is prevented when the system is booting.  When preferences are transmitted by the loginwindow at the end of
boot, a flag is cleared, and this allows subsequent Demand Sleep.

The system will not Sleep, but will Doze if some object calls setSleepSupported(kPCICantSleep) during a power change to the sleep state (this can be done by the PCI Aux Power Supply drivers, Slots99, MacRISC299, etc.).  This is not enforced with
a clamp, but sets a flag which is noticed before actually sleeping the kernel.  If the flag is set, the root steps up
one power state from Sleep to Doze, and any objects in the tree for which this is relevent will act appropriately (USB and
ADB will turn on again so that they can wake the system out of Doze (keyboard/mouse activity will cause the Display Wrangler
to be tickled)).
*/


// **********************************************************************************

IOPMrootDomain * IOPMrootDomain::construct( void )
{
    IOPMrootDomain * root;

    root = new IOPMrootDomain;
    if( root)
        root->init();

    return( root );
}

// **********************************************************************************

static void disk_sync_callout(thread_call_param_t p0, thread_call_param_t p1)
{
    IOService * rootDomain = (IOService *) p0;
    unsigned long pmRef = (unsigned long) p1;

    sync_internal();
    rootDomain->allowPowerChange(pmRef);
}

// **********************************************************************************
// start
//
// We don't do much here.  The real initialization occurs when the platform
// expert informs us we are the root.
// **********************************************************************************


bool IOPMrootDomain::start ( IOService * nub )
{
    OSDictionary *tmpDict;

    super::start(nub);

    gRootDomain = this;

    PMinit();
    setProperty("IOSleepSupported","");
    allowSleep = true;
    sleepIsSupported = true;
    systemBooting = true;
    ignoringClamshell = true;
    sleepSlider = 0;
    idleSleepPending = false;
    canSleep = true;
    wrangler = NULL;
    sleepASAP = false;
    ignoringClamshellDuringWakeup = false;
    
    tmpDict = OSDictionary::withCapacity(1);
    setProperty(kRootDomainSupportedFeatures, tmpDict);
    tmpDict->release();

    pm_vars->PMworkloop = IOWorkLoop::workLoop();				// make the workloop
    extraSleepTimer = thread_call_allocate((thread_call_func_t)sleepTimerExpired, (thread_call_param_t) this);
    clamshellWakeupIgnore = thread_call_allocate((thread_call_func_t)wakeupClamshellTimerExpired, (thread_call_param_t) this);
    diskSyncCalloutEntry = thread_call_allocate(&disk_sync_callout, (thread_call_param_t) this);

    patriarch = new IORootParent;                               // create our parent
    patriarch->init();
    patriarch->attach(this);
    patriarch->start(this);
    patriarch->youAreRoot();
    patriarch->wakeSystem();
    patriarch->addPowerChild(this);
    
    registerPowerDriver(this,ourPowerStates,number_of_power_states);

    setPMRootDomain(this);
    changePowerStateToPriv(ON_STATE);				// set a clamp until we sleep

    registerPrioritySleepWakeInterest( &sysPowerDownHandler, this, 0); // install power change handler

    // Register for a notification when IODisplayWrangler is published
    addNotification( gIOPublishNotification, serviceMatching("IODisplayWrangler"), &displayWranglerPublished, this, 0);

    registerService();						// let clients find us

    return true;
}

// **********************************************************************************
// setProperties
//
// Receive a setProperty call
// The "System Boot" property means the system is completely booted.
// **********************************************************************************
IOReturn IOPMrootDomain::setProperties ( OSObject *props_obj)
{
    OSDictionary    *dict = OSDynamicCast(OSDictionary, props_obj);
    
    if(!dict) return kIOReturnBadArgument;

    if(dict->getObject(OSString::withCString("System Boot Complete"))) {
        systemBooting = false;
        kprintf("IOPM: received System Boot Complete property");
        adjustPowerState();
    }
    
    return kIOReturnSuccess;
}


//*********************************************************************************
// youAreRoot
//
// Power Managment is informing us that we are the root power domain.
// We know we are not the root however, since we have just instantiated a parent
// for ourselves and made it the root.  We override this method so it will have
// no effect
//*********************************************************************************
IOReturn IOPMrootDomain::youAreRoot ( void )
{
    return IOPMNoErr;
}

// **********************************************************************************
// command_received
//
// No longer used
// **********************************************************************************
void IOPMrootDomain::command_received ( void * w, void * x, void * y, void * z )
{
    super::command_received(w,x,y,z);
}


// **********************************************************************************
// broadcast_aggressiveness
//
// **********************************************************************************
IOReturn broadcast_aggressiveness ( OSObject * root, void * x, void * y, void *, void * )
{
    ((IOPMrootDomain *)root)->broadcast_it((unsigned long)x,(unsigned long)y);
    return IOPMNoErr;
}


// **********************************************************************************
// broadcast_it
//
// We are behind the command gate to broadcast an aggressiveness factor.  We let the
// superclass do it, but we need to snoop on factors that affect idle sleep.
// **********************************************************************************
void IOPMrootDomain::broadcast_it (unsigned long type, unsigned long value)
{
    super::setAggressiveness(type,value);

    // Save user's spin down timer to restore after we replace it for idle sleep
    if( type == kPMMinutesToSpinDown ) user_spindown = value;

    // Use longestNonSleepSlider to calculate dimming adjust idle sleep timer
    longestNonSleepSlider = pm_vars->current_aggressiveness_values[kPMMinutesToDim];


    if ( type == kPMMinutesToSleep ) {
        if ( (sleepSlider == 0) && (value != 0) ) {
            sleepSlider = value;
            adjustPowerState();				// idle sleep is now enabled, maybe sleep now
        }
        sleepSlider = value;
        if ( sleepSlider == 0 ) {			
            adjustPowerState();				// idle sleep is now disabled
            patriarch->wakeSystem();			// make sure we're powered
        }
    }
    if ( sleepSlider > longestNonSleepSlider ) {
        extraSleepDelay = sleepSlider - longestNonSleepSlider ;
    }
    else {
        extraSleepDelay = 0;
    }
}


// **********************************************************************************
// sleepTimerExpired
//
// **********************************************************************************
static void sleepTimerExpired ( thread_call_param_t us)
{
    ((IOPMrootDomain *)us)->handleSleepTimerExpiration();
    }
    
   
static void wakeupClamshellTimerExpired ( thread_call_param_t us)
{
    ((IOPMrootDomain *)us)->stopIgnoringClamshellEventsDuringWakeup();
}

    
// **********************************************************************************
// handleSleepTimerExpiration
//
// The time between the sleep idle timeout and the next longest one has elapsed.
// It's time to sleep.  Start that by removing the clamp that's holding us awake.
// **********************************************************************************
void IOPMrootDomain::handleSleepTimerExpiration ( void )
{
    // accelerate disk spin down if spin down timer is non-zero (zero = never spin down)  
    if(0 != user_spindown)
        setQuickSpinDownTimeout();

    sleepASAP = true;
    adjustPowerState();
}


void IOPMrootDomain::stopIgnoringClamshellEventsDuringWakeup(void)
{
    OSObject *  state;

    // Allow clamshell-induced sleep now
    ignoringClamshellDuringWakeup = false;

    if ((state = getProperty(kAppleClamshellStateKey)))
        publishResource(kAppleClamshellStateKey, state);
}

//*********************************************************************************
// setAggressiveness
//
// Some aggressiveness factor has changed.  We broadcast it to the hierarchy while on
// the Power Mangement workloop thread.  This enables objects in the
// hierarchy to successfully alter their idle timers, which are all on the
// same thread.
//*********************************************************************************

IOReturn IOPMrootDomain::setAggressiveness ( unsigned long type, unsigned long newLevel )
{
    if ( pm_vars->PMcommandGate ) {
        pm_vars->PMcommandGate->runAction(broadcast_aggressiveness,(void *)type,(void *)newLevel);
    }
    
    return kIOReturnSuccess;
}


// **********************************************************************************
// sleepSystem
//
// **********************************************************************************
IOReturn IOPMrootDomain::sleepSystem ( void )
{
    kprintf("sleep demand received\n");
    if ( !systemBooting && allowSleep && sleepIsSupported ) {
        patriarch->sleepSystem();
        return kIOReturnSuccess;
    }
    if ( !systemBooting && allowSleep && !sleepIsSupported ) {
        patriarch->dozeSystem();
        return kIOReturnSuccess;
    }
    return kIOReturnSuccess;
}


// **********************************************************************************
// shutdownSystem
//
// **********************************************************************************
IOReturn IOPMrootDomain::shutdownSystem ( void )
{
    patriarch->shutDownSystem();
    return kIOReturnSuccess;
}


// **********************************************************************************
// restartSystem
//
// **********************************************************************************
IOReturn IOPMrootDomain::restartSystem ( void )
{
    patriarch->restartSystem();
    return kIOReturnSuccess;
}


// **********************************************************************************
// powerChangeDone
//
// This overrides powerChangeDone in IOService.
//
// Finder sleep and idle sleep move us from the ON state to the SLEEP_STATE.
// In this case:
// If we just finished going to the SLEEP_STATE, and the platform is capable of true sleep,
// sleep the kernel.  Otherwise switch up to the DOZE_STATE which will keep almost
// everything as off as it can get.
//
// **********************************************************************************
void IOPMrootDomain::powerChangeDone ( unsigned long previousState )
{
    OSNumber *		propertyPtr;
    unsigned short	theProperty;
    AbsoluteTime        deadline;
    
    switch ( pm_vars->myCurrentState ) {
        case SLEEP_STATE:
            if ( canSleep && sleepIsSupported ) {
                idleSleepPending = false;			// re-enable this timer for next sleep
                IOLog("System Sleep\n");
                pm_vars->thePlatform->sleepKernel();		// sleep now

		ioSPMTrace(IOPOWER_WAKE, * (int *) this);	// now we're waking

                clock_interval_to_deadline(30, kSecondScale, &deadline);	// stay awake for at least 30 seconds
                thread_call_enter_delayed(extraSleepTimer, deadline);
                idleSleepPending = true;			// this gets turned off when we sleep again
                
                // Ignore closed clamshell during wakeup and for a few seconds
                // after wakeup is complete
                ignoringClamshellDuringWakeup = true;

                gSleepOrShutdownPending = 0;        // sleep transition complete
                patriarch->wakeSystem();			// get us some power
                
                IOLog("System Wake\n");
                systemWake();					// tell the tree we're waking 
                
                // Allow drivers to request extra processing time before clamshell
                // sleep if kIOREMSleepEnabledKey is present.
                // Ignore clamshell events for at least 5 seconds 
                if(getProperty(kIOREMSleepEnabledKey)) {
                    // clamshellWakeupIgnore callout clears ignoreClamshellDuringWakeup bit   
                    clock_interval_to_deadline(5, kSecondScale, &deadline);
                    if(clamshellWakeupIgnore) thread_call_enter_delayed(clamshellWakeupIgnore, deadline);
                } else ignoringClamshellDuringWakeup = false;
                            
                propertyPtr = OSDynamicCast(OSNumber,getProperty("WakeEvent"));
                if ( propertyPtr ) {				// find out what woke us
                    theProperty = propertyPtr->unsigned16BitValue();
                    IOLog("Wake event %04x\n",theProperty);
                    if ( (theProperty == 0x0008) ||	//lid
                        (theProperty == 0x0800) ||	// front panel button
                        (theProperty == 0x0020) ||	// external keyboard
                        (theProperty == 0x0001) ) {	// internal keyboard
                        reportUserInput();
                    }
                }
                else {
                    IOLog("Unknown wake event\n");
                    reportUserInput();				// don't know, call it user input then
                }
                
                changePowerStateToPriv(ON_STATE);		// wake for thirty seconds
                powerOverrideOffPriv();
            }
            else {
                patriarch->sleepToDoze();		// allow us to step up a power state
                changePowerStateToPriv(DOZE_STATE);	// and do it
            }
            break;

        case DOZE_STATE:
            if ( previousState != DOZE_STATE ) {
                IOLog("System Doze\n");
            }
            idleSleepPending = false;			// re-enable this timer for next sleep
            gSleepOrShutdownPending = 0;
            break;
            
    	case RESTART_STATE:
            IOLog("System Restart\n");
            PEHaltRestart(kPERestartCPU);
            break;
            
    	case OFF_STATE:
            IOLog("System Halt\n");
            PEHaltRestart(kPEHaltCPU);
            break;
    }
}


// **********************************************************************************
// wakeFromDoze
//
// The Display Wrangler calls here when it switches to its highest state.  If the 
// system is currently dozing, allow it to wake by making sure the parent is
// providing power.
// **********************************************************************************
void IOPMrootDomain::wakeFromDoze( void )
{
    if ( pm_vars->myCurrentState == DOZE_STATE ) {
        canSleep = true;				// reset this till next attempt
        powerOverrideOffPriv();
        patriarch->wakeSystem();			// allow us to wake if children so desire
    }
}


// **********************************************************************************
// publishFeature
//
// Adds a new feature to the supported features dictionary
// 
// 
// **********************************************************************************
void IOPMrootDomain::publishFeature( const char * feature )
{
  OSDictionary *features = (OSDictionary *)getProperty(kRootDomainSupportedFeatures);
  
  features->setObject(feature, kOSBooleanTrue);
}


// **********************************************************************************
// newUserClient
//
// **********************************************************************************
IOReturn IOPMrootDomain::newUserClient(  task_t owningTask,  void * /* security_id */, UInt32 type, IOUserClient ** handler )
{
    IOReturn		err = kIOReturnSuccess;
    RootDomainUserClient *	client;

    client = RootDomainUserClient::withTask(owningTask);

    if( !client || (false == client->attach( this )) ||
        (false == client->start( this )) ) {
        if(client) {
            client->detach( this );
            client->release();
            client = NULL;
        }
        err = kIOReturnNoMemory;
    }
    *handler = client;	
    return err;
}

//*********************************************************************************
// receivePowerNotification
//
// The power controller is notifying us of a hardware-related power management
// event that we must handle. This is a result of an 'environment' interrupt from
// the power mgt micro.
//*********************************************************************************

IOReturn IOPMrootDomain::receivePowerNotification (UInt32 msg)
{
    if (msg & kIOPMOverTemp) {
        IOLog("Power Management received emergency overtemp signal. Going to sleep.");
        (void) sleepSystem ();
    }
    if (msg & kIOPMSetDesktopMode) {
        desktopMode = (0 != (msg & kIOPMSetValue));
        msg &= ~(kIOPMSetDesktopMode | kIOPMSetValue);
    }
    if (msg & kIOPMSetACAdaptorConnected) {
        acAdaptorConnect = (0 != (msg & kIOPMSetValue));
        msg &= ~(kIOPMSetACAdaptorConnected | kIOPMSetValue);
    }
    if (msg & kIOPMEnableClamshell) {
        ignoringClamshell = false;
    }
    if (msg & kIOPMDisableClamshell) {
        ignoringClamshell = true;
    }

    if (msg & kIOPMProcessorSpeedChange) {
	IOService *pmu = waitForService(serviceMatching("ApplePMU"));
	pmu->callPlatformFunction("prepareForSleep", false, 0, 0, 0, 0);
        pm_vars->thePlatform->sleepKernel();
	pmu->callPlatformFunction("recoverFromSleep", false, 0, 0, 0, 0);
    }

    if (msg & kIOPMSleepNow) {
      (void) sleepSystem ();
    }
    
    if (msg & kIOPMPowerEmergency) {
      (void) sleepSystem ();
    }

    if (msg & kIOPMClamshellClosed) {
        if ( !ignoringClamshell && !ignoringClamshellDuringWakeup 
                    && (!desktopMode || !acAdaptorConnect) ) {

             (void) sleepSystem ();
        }
    }

    if (msg & kIOPMPowerButton) {				// toggle state of sleep/wake
        if ( pm_vars->myCurrentState == DOZE_STATE ) {		// are we dozing?
            systemWake();					// yes, tell the tree we're waking 
            reportUserInput();					// wake the Display Wrangler
        }
        else {
            (void) sleepSystem ();
        }
    }

    // if the case has been closed, we allow
    // the machine to be put to sleep or to idle sleep

    if ( (msg & kIOPMAllowSleep) && !allowSleep ) {
	allowSleep = true;
        adjustPowerState();
    }

    // if the case has been opened, we disallow sleep/doze

    if (msg & kIOPMPreventSleep) {
	allowSleep = false;
        if ( pm_vars->myCurrentState == DOZE_STATE ) {		// are we dozing?
            systemWake();					// yes, tell the tree we're waking 
            adjustPowerState();
            reportUserInput();					// wake the Display Wrangler
        }
        else {
            adjustPowerState();
            patriarch->wakeSystem();				// make sure we have power to clamp
        }
    }

   return 0;
}


//*********************************************************************************
// sleepSupported
//
//*********************************************************************************

void IOPMrootDomain::setSleepSupported( IOOptionBits flags )
{
    if ( flags & kPCICantSleep ) {
        canSleep = false;
    }
    else {
        platformSleepSupport = flags;
    }

}

//*********************************************************************************
// requestPowerDomainState
//
// The root domain intercepts this call to the superclass.
//
// If the clamp bit is not set in the desire, then the child doesn't need the power
// state it's requesting; it just wants it.  The root ignores desires but not needs.
// If the clamp bit is not set, the root takes it that the child can tolerate no
// power and interprets the request accordingly.  If all children can thus tolerate
// no power, we are on our way to idle sleep.
//*********************************************************************************

IOReturn IOPMrootDomain::requestPowerDomainState ( IOPMPowerFlags desiredState, IOPowerConnection * whichChild, unsigned long specification )
{
    OSIterator *	iter;
    OSObject *		next;
    IOPowerConnection *	connection;
    unsigned long	powerRequestFlag = 0;
    IOPMPowerFlags	editedDesire = desiredState;

    if ( !(desiredState & kIOPMPreventIdleSleep) ) {		// if they don't really need it, they don't get it
        editedDesire = 0;
    }


    IOLockLock(pm_vars->childLock);			// recompute sleepIsSupported
                                                        // and see if all children are asleep
    iter = getChildIterator(gIOPowerPlane);
    sleepIsSupported = true;

    if ( iter ) {
        while ( (next = iter->getNextObject()) ) {
            if ( (connection = OSDynamicCast(IOPowerConnection,next)) ) {
                if ( connection == whichChild ) {
                    powerRequestFlag += editedDesire;
                    if ( desiredState & kIOPMPreventSystemSleep ) {
                        sleepIsSupported = false;
                    }
                }
                else {
                    powerRequestFlag += connection->getDesiredDomainState();
                    if ( connection->getPreventSystemSleepFlag() ) {
                        sleepIsSupported = false;
                    }
                }
            }
        }
        iter->release();
    }
    
    if ( (extraSleepDelay == 0) &&  (powerRequestFlag == 0) ) {
        sleepASAP = true;
    }
    
    adjustPowerState();					// this may put the system to sleep
    
    IOLockUnlock(pm_vars->childLock);

    editedDesire |= desiredState & kIOPMPreventSystemSleep;

    return super::requestPowerDomainState(editedDesire,whichChild,specification);
}


//*********************************************************************************
// getSleepSupported
//
//*********************************************************************************

IOOptionBits IOPMrootDomain::getSleepSupported( void )
{
    return( platformSleepSupport );
}


//*********************************************************************************
// tellChangeDown
//
// We override the superclass implementation so we can send a different message
// type to the client or application being notified.
//*********************************************************************************

bool IOPMrootDomain::tellChangeDown ( unsigned long stateNum )
{
    switch ( stateNum ) {
        case DOZE_STATE:
        case SLEEP_STATE:
            return super::tellClientsWithResponse(kIOMessageSystemWillSleep);
        case RESTART_STATE:
            return super::tellClientsWithResponse(kIOMessageSystemWillRestart);
        case OFF_STATE:
            return super::tellClientsWithResponse(kIOMessageSystemWillPowerOff);
    }
    return super::tellChangeDown(stateNum);		// this shouldn't execute
}


//*********************************************************************************
// askChangeDown
//
// We override the superclass implementation so we can send a different message
// type to the client or application being notified.
//
// This must be idle sleep since we don't ask apps during any other power change.
//*********************************************************************************

bool IOPMrootDomain::askChangeDown ( unsigned long )
{
    return super::tellClientsWithResponse(kIOMessageCanSystemSleep);
}


//*********************************************************************************
// tellNoChangeDown
//
// Notify registered applications and kernel clients that we are not
// dropping power.
//
// We override the superclass implementation so we can send a different message
// type to the client or application being notified.
//
// This must be a vetoed idle sleep, since no other power change can be vetoed.
//*********************************************************************************

void IOPMrootDomain::tellNoChangeDown ( unsigned long )
{
    return tellClients(kIOMessageSystemWillNotSleep);
}


//*********************************************************************************
// tellChangeUp
//
// Notify registered applications and kernel clients that we are raising power.
//
// We override the superclass implementation so we can send a different message
// type to the client or application being notified.
//*********************************************************************************

void IOPMrootDomain::tellChangeUp ( unsigned long stateNum)
{
    if ( stateNum == ON_STATE ) {
        return tellClients(kIOMessageSystemHasPoweredOn);
    }
}

//*********************************************************************************
// reportUserInput
//
//*********************************************************************************

void IOPMrootDomain::reportUserInput ( void )
{
    OSIterator * iter;

    if(!wrangler) {
        iter = getMatchingServices(serviceMatching("IODisplayWrangler"));
        if(iter) {
            wrangler = (IOService *) iter->getNextObject();
            iter->release();
        }
    }

    if(wrangler)
        wrangler->activityTickle(0,0);
}

//*********************************************************************************
// setQuickSpinDownTimeout
//
//*********************************************************************************

void IOPMrootDomain::setQuickSpinDownTimeout ( void )
{
    //IOLog("setQuickSpinDownTimeout\n");
    super::setAggressiveness((unsigned long)kPMMinutesToSpinDown,(unsigned long)1);
}

//*********************************************************************************
// restoreUserSpinDownTimeout
//
//*********************************************************************************

void IOPMrootDomain::restoreUserSpinDownTimeout ( void )
{
    super::setAggressiveness((unsigned long)kPMMinutesToSpinDown,(unsigned long)user_spindown);
}

//*********************************************************************************
// changePowerStateTo & changePowerStateToPriv
//
// Override of these methods for logging purposes.
//*********************************************************************************

IOReturn IOPMrootDomain::changePowerStateTo ( unsigned long ordinal )
{
    ioSPMTrace(IOPOWER_ROOT, * (int *) this, (int) true, (int) ordinal);

    return super::changePowerStateTo(ordinal);
}

IOReturn IOPMrootDomain::changePowerStateToPriv ( unsigned long ordinal )
{
    ioSPMTrace(IOPOWER_ROOT, * (int *) this, (int) false, (int) ordinal);

    return super::changePowerStateToPriv(ordinal);
}


//*********************************************************************************
// sysPowerDownHandler
//
// Receives a notification when the RootDomain changes state. 
//
// Allows us to take action on system sleep, power down, and restart after
// applications have received their power change notifications and replied,
// but before drivers have powered down. We perform a vfs sync on power down.
//*********************************************************************************

IOReturn IOPMrootDomain::sysPowerDownHandler( void * target, void * refCon,
                                    UInt32 messageType, IOService * service,
                                    void * messageArgument, vm_size_t argSize )
{
    IOReturn ret;
    IOPowerStateChangeNotification * params = (IOPowerStateChangeNotification *) messageArgument;
    IOPMrootDomain *		     rootDomain = OSDynamicCast(IOPMrootDomain, service);

    if(!rootDomain)
        return kIOReturnUnsupported;

    switch (messageType) {
        case kIOMessageSystemWillSleep:
            rootDomain->powerOverrideOnPriv();		// start ignoring children's requests
                                                        // (fall through to other cases)

            // Interested applications have been notified of an impending power
            // change and have acked (when applicable).
            // This is our chance to save whatever state we can before powering
            // down.
            // We call sync_internal defined in xnu/bsd/vfs/vfs_syscalls.c,
            // via callout

            // We will ack within 20 seconds
            params->returnValue = 20 * 1000 * 1000;

            if ( ! OSCompareAndSwap( 0, 1, &gSleepOrShutdownPending ) )
            {
                // Purposely delay the ack and hope that shutdown occurs quickly.
                // Another option is not to schedule the thread and wait for
                // ack timeout...
                AbsoluteTime deadline;
                clock_interval_to_deadline( 30, kSecondScale, &deadline );
                thread_call_enter1_delayed( rootDomain->diskSyncCalloutEntry, 
                                            (thread_call_param_t)params->powerRef,
                                            deadline );
            }
            else
                thread_call_enter1(rootDomain->diskSyncCalloutEntry, (thread_call_param_t)params->powerRef);
            ret = kIOReturnSuccess;
            break;

        case kIOMessageSystemWillPowerOff:
        case kIOMessageSystemWillRestart:
            ret = kIOReturnUnsupported;
            break;

        default:
            ret = kIOReturnUnsupported;
            break;
    }
    return ret;
}
		
//*********************************************************************************
// displayWranglerNotification
//
// Receives a notification when the IODisplayWrangler changes state.
//
// Allows us to take action on display dim/undim.
//
// When the display goes dim we:
// - Start the idle sleep timer
// - set the quick spin down timeout
//
// On wake from display dim:
// - Cancel the idle sleep timer
// - restore the user's chosen spindown timer from the "quick" spin down value
//*********************************************************************************

IOReturn IOPMrootDomain::displayWranglerNotification( void * target, void * refCon,
                                    UInt32 messageType, IOService * service,
                                    void * messageArgument, vm_size_t argSize )
{
    IOPMrootDomain *                rootDomain = OSDynamicCast(IOPMrootDomain, (IOService *)target);
    AbsoluteTime                 deadline;
    static bool                  deviceAlreadyPoweredOff = false;

    if(!rootDomain)
        return kIOReturnUnsupported;

    switch (messageType) {
       case kIOMessageDeviceWillPowerOff:
            // The IODisplayWrangler has powered off either because of idle display sleep
            // or force system sleep.
            
            // The display wrangler will send the DeviceWillPowerOff message 4 times until
            // it gets into its lowest state. We only want to act on the first of those 4.
            if( deviceAlreadyPoweredOff ) return kIOReturnUnsupported;

           deviceAlreadyPoweredOff = true;

           if( rootDomain->extraSleepDelay ) {

                // start the extra sleep timer
                clock_interval_to_deadline(rootDomain->extraSleepDelay*60, kSecondScale, &deadline );
                thread_call_enter_delayed(rootDomain->extraSleepTimer, deadline);
                rootDomain->idleSleepPending = true;

            } else {

                // accelerate disk spin down if spin down timer is non-zero (zero = never spin down)
                // and if system sleep is non-Never
                if( (0 != rootDomain->user_spindown) && (0 != rootDomain->sleepSlider) )
                    rootDomain->setQuickSpinDownTimeout();
            }

             break;

        case kIOMessageDeviceHasPoweredOn:

            // The display has powered on either because of UI activity or wake from sleep/doze
            deviceAlreadyPoweredOff = false;
            rootDomain->adjustPowerState();
            

            // cancel any pending idle sleep
            if(rootDomain->idleSleepPending) {
                thread_call_cancel(rootDomain->extraSleepTimer);
                rootDomain->idleSleepPending = false;
            }

            // Change the spindown value back to the user's selection from our accelerated setting
            if(0 != rootDomain->user_spindown)
                rootDomain->restoreUserSpinDownTimeout();

            // Put on the policy maker's on clamp.

            break;

         default:
             break;
     }
     return kIOReturnUnsupported;
 }

//*********************************************************************************
// displayWranglerPublished
//
// Receives a notification when the IODisplayWrangler is published.
// When it's published we install a power state change handler.
//
//*********************************************************************************

bool IOPMrootDomain::displayWranglerPublished( void * target, void * refCon,
                                    IOService * newService)
{
    IOPMrootDomain *                rootDomain = OSDynamicCast(IOPMrootDomain, (IOService *)target);

    if(!rootDomain)
        return false;

       rootDomain->wrangler = newService;

       // we found the display wrangler, now install a handler
       if( !rootDomain->wrangler->registerInterest( gIOGeneralInterest, &displayWranglerNotification, target, 0) ) {
               IOLog("IOPMrootDomain::displayWranglerPublished registerInterest failed\n");
               return false;
       }

       return true;
}


//*********************************************************************************
// adjustPowerState
//
// Some condition that affects our wake/sleep/doze decision has changed.
//
// If the sleep slider is in the off position, we cannot sleep or doze.
// If the enclosure is open, we cannot sleep or doze.
// If the system is still booting, we cannot sleep or doze.
//
// In those circumstances, we prevent sleep and doze by holding power on with
// changePowerStateToPriv(ON).
//
// If the above conditions do not exist, and also the sleep timer has expired, we
// allow sleep or doze to occur with either changePowerStateToPriv(SLEEP) or
// changePowerStateToPriv(DOZE) depending on whether or not we already know the
// platform cannot sleep.
//
// In this case, sleep or doze will either occur immediately or at the next time
// that no children are holding the system out of idle sleep via the 
// kIOPMPreventIdleSleep flag in their power state arrays.
//*********************************************************************************

void IOPMrootDomain::adjustPowerState( void )
{
    if ( (sleepSlider == 0) ||
        ! allowSleep ||
        systemBooting ) {
        changePowerStateToPriv(ON_STATE);
    }
    else {
        if ( sleepASAP ) {
            sleepASAP = false;
            if ( sleepIsSupported ) {
                changePowerStateToPriv(SLEEP_STATE);
            }
            else {
                changePowerStateToPriv(DOZE_STATE);
            }
        }
    }
}


/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

#undef super
#define super IOService

OSDefineMetaClassAndStructors(IORootParent, IOService)

// This array exactly parallels the state array for the root domain.
// Power state changes initiated by a device can be vetoed by a client of the device, and
// power state changes initiated by the parent of a device cannot be vetoed by a client of the device,
// so when the root domain wants a power state change that cannot be vetoed (e.g. demand sleep), it asks
// its parent to make the change.  That is the reason for this complexity.

static IOPMPowerState patriarchPowerStates[number_of_power_states] = {
    {1,0,0,0,0,0,0,0,0,0,0,0},                                          // off
    {1,0,RESTART_POWER,0,0,0,0,0,0,0,0,0},                              // reset
    {1,0,SLEEP_POWER,0,0,0,0,0,0,0,0,0},                                // sleep
    {1,0,DOZE_POWER,0,0,0,0,0,0,0,0,0},                         	// doze
    {1,0,ON_POWER,0,0,0,0,0,0,0,0,0}                                    // running
};

bool IORootParent::start ( IOService * nub )
{
    mostRecentChange = ON_STATE;
    super::start(nub);
    PMinit();
    registerPowerDriver(this,patriarchPowerStates,number_of_power_states);
    powerOverrideOnPriv();
    return true;
}


void IORootParent::shutDownSystem ( void )
{
    mostRecentChange = OFF_STATE;
    changePowerStateToPriv(OFF_STATE);
}


void IORootParent::restartSystem ( void )
{
    mostRecentChange = RESTART_STATE;
    changePowerStateToPriv(RESTART_STATE);
}


void IORootParent::sleepSystem ( void )
{
    mostRecentChange = SLEEP_STATE;
    changePowerStateToPriv(SLEEP_STATE);
}


void IORootParent::dozeSystem ( void )
{
    mostRecentChange = DOZE_STATE;
    changePowerStateToPriv(DOZE_STATE);
}

// Called in demand sleep when sleep discovered to be impossible after actually attaining that state.
// This brings the parent to doze, which allows the root to step up from sleep to doze.

// In idle sleep, do nothing because the parent is still on and the root can freely change state.

void IORootParent::sleepToDoze ( void )
{
    if ( mostRecentChange == SLEEP_STATE ) {
        changePowerStateToPriv(DOZE_STATE);
    }
}


void IORootParent::wakeSystem ( void )
{
    mostRecentChange = ON_STATE;
    changePowerStateToPriv(ON_STATE);
}