1/* 2 * Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved. 3 * 4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ 5 * 6 * This file contains Original Code and/or Modifications of Original Code 7 * as defined in and that are subject to the Apple Public Source License 8 * Version 2.0 (the 'License'). You may not use this file except in 9 * compliance with the License. The rights granted to you under the License 10 * may not be used to create, or enable the creation or redistribution of, 11 * unlawful or unlicensed copies of an Apple operating system, or to 12 * circumvent, violate, or enable the circumvention or violation of, any 13 * terms of an Apple operating system software license agreement. 14 * 15 * Please obtain a copy of the License at 16 * http://www.opensource.apple.com/apsl/ and read it before using this file. 17 * 18 * The Original Code and all software distributed under the License are 19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 23 * Please see the License for the specific language governing rights and 24 * limitations under the License. 25 * 26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ 27 */ 28/* 29Copyright (c) 1999 Apple Computer, Inc. All rights reserved. 30 31HISTORY 32 1999-4-15 Godfrey van der Linden(gvdl) 33 Created. 34*/ 35#ifndef _IOKIT_IOFILTERINTERRUPTEVENTSOURCE_H 36#define _IOKIT_IOFILTERINTERRUPTEVENTSOURCE_H 37 38#include <IOKit/IOInterruptEventSource.h> 39 40class IOService; 41 42/*! @class IOFilterInterruptEventSource : public IOInterruptEventSource 43 @abstract Filtering varient of the $link IOInterruptEventSource. 44 @discussion An interrupt event source that calls the client to determine if a interrupt event needs to be scheduled on the work loop. A filter interrupt event source call's the client in the primary interrupt context, the client can then interrogate its hardware and determine if the interrupt needs to be processed yet. 45<br><br> 46 As the routine is called in the primary interrupt context great care must be taken in the writing of this routine. In general none of the generic IOKit environment is safe to call in this context. We intend this routine to be used by hardware that can interrogate its registers without destroying state. Primarily this variant of event sources will be used by drivers that share interrupts. The filter routine will determine if the interrupt is a real interrupt or a ghost and thus optimise the work thread context switch away. 47<br><br> 48If you are implementing 'SoftDMA' (or pseudo-DMA), you may not want the I/O Kit to automatically start your interrupt handler routine on your work loop when your filter routine returns true. In this case, you may choose to have your filter routine schedule the work on the work loop itself and then return false. If you do this, the interrupt will not be disabled in hardware and you could receive additional primary interrupts before your work loop���level service routine completes. Because this scheme has implications for synchronization between your filter routine and your interrupt service routine, you should avoid doing this unless your driver requires SoftDMA. 49<br><br> 50CAUTION: Called in primary interrupt context, if you need to disable interrupt to guard you registers against an unexpected call then it is better to use a straight IOInterruptEventSource and its secondary interrupt delivery mechanism. 51*/ 52class IOFilterInterruptEventSource : public IOInterruptEventSource 53{ 54 OSDeclareDefaultStructors(IOFilterInterruptEventSource) 55 56public: 57/*! 58 @typedef Filter 59 @discussion C Function pointer to a routine to call when an interrupt occurs. 60 @param owner Pointer to the owning/client instance. 61 @param sender Where is the interrupt comming from. 62 @result false if this interrupt can be ignored. */ 63 typedef bool (*Filter)(OSObject *, IOFilterInterruptEventSource *); 64 65/*! @defined IOFilterInterruptAction 66 @discussion Backward compatibilty define for the old non-class scoped type definition. See $link IOFilterInterruptSource::Filter */ 67#define IOFilterInterruptAction IOFilterInterruptEventSource::Filter 68 69private: 70 // Hide the superclass initializers 71 virtual bool init(OSObject *inOwner, 72 IOInterruptEventSource::Action inAction = 0, 73 IOService *inProvider = 0, 74 int inIntIndex = 0); 75 76 static IOInterruptEventSource * 77 interruptEventSource(OSObject *inOwner, 78 IOInterruptEventSource::Action inAction = 0, 79 IOService *inProvider = 0, 80 int inIntIndex = 0); 81 82protected: 83/*! @var filterAction Filter callout */ 84 Filter filterAction; 85 86/*! @struct ExpansionData 87 @discussion This structure will be used to expand the capablilties of the IOWorkLoop in the future. 88 */ 89 struct ExpansionData { }; 90 91/*! @var reserved 92 Reserved for future use. (Internal use only) */ 93 ExpansionData *reserved; 94 95public: 96/*! @function filterInterruptEventSource 97 @abstract Factor method to create and initialise an IOFilterInterruptEventSource. See $link init. 98 @param owner Owner/client of this event source. 99 @param action 'C' Function to call when something happens. 100 @param filter 'C' Function to call when interrupt occurs. 101 @param provider Service that provides interrupts. 102 @param intIndex Defaults to 0. 103 @result a new event source if succesful, 0 otherwise. */ 104 static IOFilterInterruptEventSource * 105 filterInterruptEventSource(OSObject *owner, 106 IOInterruptEventSource::Action action, 107 Filter filter, 108 IOService *provider, 109 int intIndex = 0); 110 111/*! @function init 112 @abstract Primary initialiser for the IOFilterInterruptEventSource class. 113 @param owner Owner/client of this event source. 114 @param action 'C' Function to call when something happens. 115 @param filter 'C' Function to call in primary interrupt context. 116 @param provider Service that provides interrupts. 117 @param intIndex Interrupt source within provider. Defaults to 0. 118 @result true if the inherited classes and this instance initialise 119successfully. */ 120 virtual bool init(OSObject *owner, 121 IOInterruptEventSource::Action action, 122 Filter filter, 123 IOService *provider, 124 int intIndex = 0); 125 126 127/*! @function signalInterrupt 128 @abstract Cause the work loop to schedule the action. 129 @discussion Cause the work loop to schedule the interrupt action even if the filter routine returns 'false'. Note well the interrupting condition MUST be cleared from the hardware otherwise an infinite process interrupt loop will occur. Use this function when SoftDMA is desired. See $link IOFilterInterruptSource::Filter */ 130 virtual void signalInterrupt(); 131 132/*! @function getFilterAction 133 @abstract Get'ter for filterAction variable. 134 @result value of filterAction. */ 135 virtual Filter getFilterAction() const; 136 137/*! @function normalInterruptOccurred 138 @abstract Override $link IOInterruptEventSource::normalInterruptOccured to make a filter callout. */ 139 virtual void normalInterruptOccurred(void *self, IOService *prov, int ind); 140 141/*! @function disableInterruptOccurred 142 @abstract Override $link IOInterruptEventSource::disableInterruptOccurred to make a filter callout. */ 143 virtual void disableInterruptOccurred(void *self, IOService *prov, int ind); 144 145private: 146 OSMetaClassDeclareReservedUnused(IOFilterInterruptEventSource, 0); 147 OSMetaClassDeclareReservedUnused(IOFilterInterruptEventSource, 1); 148 OSMetaClassDeclareReservedUnused(IOFilterInterruptEventSource, 2); 149 OSMetaClassDeclareReservedUnused(IOFilterInterruptEventSource, 3); 150 OSMetaClassDeclareReservedUnused(IOFilterInterruptEventSource, 4); 151 OSMetaClassDeclareReservedUnused(IOFilterInterruptEventSource, 5); 152 OSMetaClassDeclareReservedUnused(IOFilterInterruptEventSource, 6); 153 OSMetaClassDeclareReservedUnused(IOFilterInterruptEventSource, 7); 154}; 155 156#endif /* !_IOKIT_IOFILTERINTERRUPTEVENTSOURCE_H */ 157