/*
 * Copyright (c) 2019-2019 Apple 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_UIOINTERRUPTDISPATCHSOURCE_H
#define _IOKIT_UIOINTERRUPTDISPATCHSOURCE_H

#include <DriverKit/IODispatchQueue.iig>
#include <DriverKit/IOService.iig>

struct IOInterruptDispatchSourcePayload {
	uint64_t time;
	uint64_t count;
};

/*!
 * @class IOInterruptDispatchSource
 *
 * @abstract
 * IOInterruptDispatchSource delivers interrupts to a handler block on a dispatch queue.
 *
 * @discussion
 * A driver can run code in response to an interrupt from a device, specified as an IOService
 * and index. The code runs at normal thread level, but is notified with the mach_absolute_time
 * the primary interrupt fired. For IOPCIDevices, only MSI interrupt sources are supported.
 */
 
class NATIVE KERNEL IOInterruptDispatchSource : public IODispatchSource
{
public:

    /*!
     * @brief       Create an IOInterruptDispatchSource for an interrupt by index from an IOService provider.
     * @param       provider The IOService object representing the HW device producing the interrupt.
     * @param       index Index for the interrupt.
     * @param       queue Target queue to run the handler block.
     * @param       source Created source with +1 retain count to be released by the caller.
     * @return      kIOReturnSuccess on success. See IOReturn.h for error codes.
     */
	static kern_return_t
	Create(IOService * provider,
	    uint32_t index,
	    IODispatchQueue * queue,
	    IOInterruptDispatchSource ** source) LOCAL;

	virtual bool
	init() override;

	virtual void
	free() override;

    /*!
     * @brief       Set the handler block to run when the interupt fires.
     * @param       action OSAction instance specifying the callback method. The OSAction object will be retained
     *              until SetHandler is called again or the event source is cancelled.
     * @return      kIOReturnSuccess on success. See IOReturn.h for error codes.
     */
	virtual kern_return_t
	    SetHandler(
		OSAction * action TYPE(InterruptOccurred)) LOCAL;

    /*!
     * @brief       Control the enable state of the interrupt source.
     * @param       enable Pass true to enable the source or false to disable.
     * @param       handler Optional block to be executed after the interrupt has been disabled and any pending
     *              interrupt handlers completed.
     * @return      kIOReturnSuccess on success. See IOReturn.h for error codes.
     */
	virtual kern_return_t
	SetEnableWithCompletion(
		bool enable,
		IODispatchSourceCancelHandler handler) override LOCAL;

    /*!
     * @brief       Cancel all callbacks from the event source.
     * @discussion  After cancellation, the source can only be freed. It cannot be reactivated.
     * @param       handler Handler block to be invoked after any callbacks have completed.
     * @return      kIOReturnSuccess on success. See IOReturn.h for error codes.
     */
	virtual kern_return_t
	Cancel(IODispatchSourceCancelHandler handler) override LOCAL;

private:
	virtual kern_return_t
	CheckForWork(bool synchronous) override LOCAL;

	virtual void
	InterruptOccurred(
		OSAction * action TARGET,
		uint64_t   count,
		uint64_t   time) REPLY LOCAL;
};

#endif /* ! _IOKIT_UIOINTERRUPTDISPATCHSOURCE_H */