This is xnu-8019. See this file in:
/*
 * Copyright (c) 2005 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 *
 * 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. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 *
 * 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_OSREFERENCE_LICENSE_HEADER_END@
 */

#ifndef _IOKIT_IODMAEVENTSOURCE_H
#define _IOKIT_IODMAEVENTSOURCE_H

#include <libkern/c++/OSPtr.h>
#include <IOKit/IOService.h>
#include <IOKit/IODMACommand.h>
#include <IOKit/IODMAController.h>
#include <IOKit/IOEventSource.h>

class IODMAController;

class IODMAEventSource : public IOEventSource
{
	OSDeclareDefaultStructors(IODMAEventSource);

	friend class IODMAController;

public:
	typedef void (*Action)(OSObject *owner, IODMAEventSource *dmaES, IODMACommand *dmaCommand, IOReturn status, IOByteCount actualByteCount, AbsoluteTime timeStamp);
#define IODMAEventAction IODMAEventSource::Action

protected:
	virtual void completeDMACommand(IODMACommand *dmaCommand);
	virtual void notifyDMACommand(IODMACommand *dmaCommand, IOReturn status, IOByteCount actualByteCount, AbsoluteTime timeStamp);

public:
	static OSPtr<IODMAEventSource> dmaEventSource(OSObject *owner,
	    IOService *provider,
	    Action completion = NULL,
	    Action notification = NULL,
	    UInt32 dmaIndex = 0);

	virtual IOReturn startDMACommand(IODMACommand *dmaCommand, IODirection direction, IOByteCount byteCount = 0, IOByteCount byteOffset = 0);
	virtual IOReturn stopDMACommand(bool flush = false, uint64_t timeout = UINT64_MAX);

	virtual IOReturn queryDMACommand(IODMACommand **dmaCommand, IOByteCount *transferCount, bool waitForIdle = false);

	virtual IOByteCount getFIFODepth(IODirection direction = kIODirectionNone);
	virtual IOReturn setFIFODepth(IOByteCount depth);
	virtual IOByteCount validFIFODepth(IOByteCount depth, IODirection direction);

	virtual IOReturn setFrameSize(UInt8 byteCount);

	virtual IOReturn setDMAConfig(UInt32 dmaIndex);
	virtual bool validDMAConfig(UInt32 dmaIndex);

private:
	IOService       *dmaProvider;
	OSPtr<IODMAController> dmaController;
	UInt32          dmaIndex;
	queue_head_t    dmaCommandsCompleted;
	IOSimpleLock    *dmaCommandsCompletedLock;
	Action          dmaCompletionAction;
	Action          dmaNotificationAction;
	bool            dmaSynchBusy;

	virtual bool init(OSObject *owner,
	    IOService *provider,
	    Action completion = NULL,
	    Action notification = NULL,
	    UInt32 dmaIndex = 0);
	virtual bool checkForWork(void) APPLE_KEXT_OVERRIDE;
	virtual void free(void) APPLE_KEXT_OVERRIDE;
};

#endif /* _IOKIT_IODMAEVENTSOURCE_H */