xref: /xnu-11215/iokit/Examples/drvGenericInterruptController/GenericInterruptController.cpp (revision e13b1fa5)

/*
 * Copyright (c) 1998-2000 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,
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/*
 * Copyright (c) 1999 Apple Computer, Inc.  All rights reserved.
 *
 *  DRI: Josh de Cesare
 */

#include <IOKit/IOPlatformExpert.h>

#include "GenericInterruptController.h"

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

#undef  super
#define super IOInterruptController

IODefineMetaClassAndStructors(GenericInterruptController,
			      IOInterruptController);

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


bool GenericInterruptController::start(IOService *provider)
{
  IOInterruptAction    handler;
  IOSymbol             *interruptControllerName;

  // If needed call the parents start.
  if (!super::start(provider))
    return false;

  // Map the device's memory and initalize its state.

  // For now you must allocate storage for the vectors.
  // This will probably changed to something like: initVectors(numVectors).
  // In the mean time something like this works well.
#if 0
  // Allocate the memory for the vectors.
  vectors = (IOInterruptVector *)IOMalloc(numVectors *
					  sizeof(IOInterruptVector));
  if (vectors == NULL) return false;
  bzero(vectors, numVectors * sizeof(IOInterruptVector));

  // Allocate locks for the vectors.
  for (cnt = 0; cnt < numVectors; cnt++) {
    vectors[cnt].interruptLock = IOLockAlloc();
    if (vectors[cnt].interruptLock == NULL) {
      for (cnt = 0; cnt < numVectors; cnt++) {
	if (vectors[cnt].interruptLock != NULL)
	  IOLockFree(vectors[cnt].interruptLock);
      }
    }
  }
#endif

  // If you know that this interrupt controller is the primary
  // interrupt controller, use this to set it nub properties properly.
  // This may be done by the nub's creator.
  getPlatform()->setCPUInterruptProperties(provider);

  // register the interrupt handler so it can receive interrupts.
  handler = getInterruptHandlerAddress();
  provider->registerInterrupt(0, this, handler, 0);

  // Just like any interrupt source, you must enable it to receive interrupts.
  provider->enableInterrupt(0);

  // Set interruptControllerName to the proper symbol.
  //interruptControllerName = xxx;

  // Register this interrupt controller so clients can find it.
  getPlatform()->registerInterruptController(interruptControllerName, this);

  // All done, so return true.
  return true;
}

IOReturn GenericInterruptController::getInterruptType(IOService *nub,
						      int source,
						      int *interruptType)
{
  if (interruptType == 0) return kIOReturnBadArgument;

  // Given the nub and source, set interruptType to level or edge.

  return kIOReturnSuccess;
}

// Sadly this just has to be replicated in every interrupt controller.
IOInterruptAction GenericInterruptController::getInterruptHandlerAddress(void)
{
  return (IOInterruptAction)handleInterrupt;
}

// Handle all current interrupts.
IOReturn GenericInterruptController::handleInterrupt(void * refCon,
						     IOService * nub,
						     int source)
{
  IOInterruptVector *vector;
  int               vectorNumber;

  while (1) {
    // Get vectorNumber from hardware some how and clear the event.

    // Break if there are no more vectors to handle.
    if (vectorNumber == 0/*kNoVector*/) break;

    // Get the vector's date from the controller's array.
    vector = &vectors[vectorNumber];

    // Set the vector as active. This store must compleat before
    // moving on to prevent the disableInterrupt fuction from
    // geting out of sync.
    vector->interruptActive = 1;
    //sync();
    //isync();

    // If the vector is not disabled soft, handle it.
    if (!vector->interruptDisabledSoft) {
      // Prevent speculative exacution as needed on your processor.
      //isync();

      // Call the handler if it exists.
      if (vector->interruptRegistered) {
	vector->handler(vector->target, vector->refCon,
			vector->nub, vector->source);
      }
    } else {
      // Hard disable the vector if is was only soft disabled.
      vector->interruptDisabledHard = 1;
      disableVectorHard(vectorNumber, vector);
    }

    // Done with this vector so, set it back to inactive.
    vector->interruptActive = 0;
  }

  return kIOReturnSuccess;
}

bool GenericInterruptController::vectorCanBeShared(long vectorNumber,
						   IOInterruptVector *vector)
{
  // Given the vector number and the vector data, return if it can be shared.
  return true;
}

void GenericInterruptController::initVector(long vectorNumber,
					    IOInterruptVector *vector)
{
  // Given the vector number and the vector data,
  // get the hardware ready for the vector to generate interrupts.
  // Make sure the vector is left disabled.
}

void GenericInterruptController::disableVectorHard(long vectorNumber,
						   IOInterruptVector *vector)
{
  // Given the vector number and the vector data,
  // disable the vector at the hardware.
}

void GenericInterruptController::enableVector(long vectorNumber,
					      IOInterruptVector *vector)
{
  // Given the vector number and the vector data,
  // enable the vector at the hardware.
}

void GenericInterruptController::causeVector(long vectorNumber,
					     IOInterruptVector *vector)
{
  // Given the vector number and the vector data,
  // Set the vector pending and cause an interrupt at the parent controller.

  // cause the interrupt at the parent controller.  Source is usually zero,
  // but it could be different for your controller.
  getPlatform()->causeInterrupt(0);
}