xnu-792.tar.gz

[apple/xnu.git] / iokit / Kernel / IOPMPowerStateQueue.cpp

/*
 * Copyright (c) 2001-2002 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 *
 * The contents of this file constitute Original Code as defined in and
 * are subject to the Apple Public Source License Version 1.1 (the
 * "License").  You may not use this file except in compliance with the
 * License.  Please obtain a copy of the License at
 * http://www.apple.com/publicsource and read it before using this file.
 *
 * This 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 OR NON-INFRINGEMENT.  Please see the
 * License for the specific language governing rights and limitations
 * under the License.
 *
 * @APPLE_LICENSE_HEADER_END@
 */
 
#include "IOPMPowerStateQueue.h"
#undef super
#define super IOEventSource
OSDefineMetaClassAndStructors(IOPMPowerStateQueue, IOEventSource);

IOPMPowerStateQueue *IOPMPowerStateQueue::PMPowerStateQueue(OSObject *inOwner)
{
    IOPMPowerStateQueue     *me = new IOPMPowerStateQueue;

    if(me && !me->init(inOwner, 0) )
    {
        me->release();
        return NULL;
    }

    return me;
}

bool IOPMPowerStateQueue::init(OSObject *owner, Action action)
{
    if(!(super::init(owner, (IOEventSource::Action) action))) return false;

    // Queue of powerstate changes
    changes = NULL;

    return true;
}


bool IOPMPowerStateQueue::unIdleOccurred(IOService *inTarget, unsigned long inState)
{
    PowerChangeEntry             *new_one = NULL;

    new_one = (PowerChangeEntry *)IOMalloc(sizeof(PowerChangeEntry));
    if(!new_one) return false;
    
    new_one->actionType = IOPMPowerStateQueue::kUnIdle;
    new_one->state = inState;
    new_one->target = inTarget;
    
    // Change to queue
    OSEnqueueAtomic((void **)&changes, (void *)new_one, 0);
    
    signalWorkAvailable();

    return true;
}

// checkForWork() is called in a gated context
bool IOPMPowerStateQueue::checkForWork()
{
    PowerChangeEntry            *theNode;
    int                         theState;
    IOService                   *theTarget;
    UInt16                      theAction;
    
    // Dequeue and process the state change request
    if((theNode = (PowerChangeEntry *)OSDequeueAtomic((void **)&changes, 0)))
    {
        theState = theNode->state;
        theTarget = theNode->target;
        theAction = theNode->actionType;
        IOFree((void *)theNode, sizeof(PowerChangeEntry));
        
        switch (theAction)
        {
            case kUnIdle:
                theTarget->command_received(theState, 0, 0, 0);
                break;
        }
    }

    // Return true if there's more work to be done
    if(changes) return true;
    else return false;
}