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) 1998 Apple Computer, Inc. All rights reserved. 30 31HISTORY 32 1998-7-13 Godfrey van der Linden(gvdl) 33 Created. 34 1998-10-30 Godfrey van der Linden(gvdl) 35 Converted to C++ 36*/ 37 38#ifndef _IOKIT_IOINTERRUPTEVENTSOURCE_H 39#define _IOKIT_IOINTERRUPTEVENTSOURCE_H 40 41#include <IOKit/IOEventSource.h> 42 43class IOService; 44 45/*! @class IOInterruptEventSource : public IOEventSource 46 @abstract Event source for interrupt delivery to work-loop based drivers. 47 @discussion The IOInterruptEventSource is a generic object that delivers calls interrupt routines in it's client in a guaranteed single-threaded manner. IOInterruptEventSource is part of the IOKit $link IOWorkLoop infrastructure where the semantic that one and only one action method is executing within a work-loops event chain. 48<br><br> 49When the action method is called in the client member function will receive 2 arguments, (IOEventSource *) sender and (int) count, See $link IOInterruptEventSource::Action. Where sender will be reference to the interrupt that occurred and the count will be computed by the difference between the $link producerCount and $link consumerCount. This number may not be reliable as no attempt is made to adjust for around the world type problems but is provided for general information and statistic gathering. 50<br><br> 51In general a client will use the factory member function to create and initialise the event source and then add it to their work-loop. It is the work loop's responsiblity to maintain the new event source in it's event chain. See $link IOWorkLoop. 52<br><br> 53An interrupt event source attaches itself to the given provider's interrupt source at initialisation time. At this time it determines if it is connected to a level or edge triggered interrupt. If the interrupt is an level triggered interrupt the event source automatically disables the interrupt source at primary interrupt time and after it call's the client it automatically reenables the interrupt. This action is fairly expensive but it is 100% safe and defaults sensibly so that the driver writer does not have to implement type dependant interrupt routines. So to repeat, the driver writer does not have to be concerned by the actual underlying interrupt mechanism as the event source hides the complexity. 54<br><br> 55Saying this if the hardware is a multi-device card, for instance a 4 port NIC, where all of the devices are sharing one level triggered interrupt AND it is possible to determine each port's interrupt state non-destructively then the $link IOFilterInterruptEventSource would be a better choice. 56<br><br> 57Warning: All IOInterruptEventSources are created in the disabled state. If you want to actually schedule interrupt delivery do not forget to enable the source. 58*/ 59class IOInterruptEventSource : public IOEventSource 60{ 61 OSDeclareDefaultStructors(IOInterruptEventSource) 62 63public: 64/*! @typedef Action 65 @discussion 'C' pointer prototype of functions that are called in a single threaded context when an interrupt occurs. 66 @param owner Pointer to client instance. 67 @param sender Pointer to generation interrupt event source. 68 @param count Number of interrupts seen before delivery. */ 69 typedef void (*Action)(OSObject *, IOInterruptEventSource *, int count); 70 71/*! @defined IOInterruptEventAction 72 @discussion Backward compatibilty define for the old non-class scoped type definition. See $link IOInterruptEventSource::Action */ 73#define IOInterruptEventAction IOInterruptEventSource::Action 74 75protected: 76/*! @var provider IOService that provides interrupts for delivery. */ 77 IOService *provider; 78 79/*! @var intIndex */ 80 int intIndex; 81 82/*! @var producerCount 83 Current count of produced interrupts that have been received. */ 84 volatile unsigned int producerCount; 85 86/*! @var consumerCount 87 Current count of produced interrupts that the owner has been informed of. */ 88 unsigned int consumerCount; 89 90/*! @var autoDisable Do we need to automatically disable the interrupt source when we take an interrupt, i.e. we are level triggered. */ 91 bool autoDisable; 92 93/*! @var explicitDisable Has the user expicitly disabled this event source, if so then do not overide their request when returning from the callout */ 94 bool explicitDisable; 95 96/*! @struct ExpansionData 97 @discussion This structure will be used to expand the capablilties of the IOWorkLoop in the future. 98 */ 99 struct ExpansionData { }; 100 101/*! @var reserved 102 Reserved for future use. (Internal use only) */ 103 ExpansionData *reserved; 104 105/*! @function free 106 @abstract Sub-class implementation of free method, disconnects from the interrupt source. */ 107 virtual void free(); 108 109/*! @function checkForWork 110 @abstract Pure Virtual member function used by IOWorkLoop for issueing a client calls. 111 @discussion This function called when the work-loop is ready to check for any work to do and then to call out the owner/action. 112 @result Return true if this function needs to be called again before all its outstanding events have been processed. */ 113 virtual bool checkForWork(); 114 115public: 116 117/*! @function interruptEventSource 118 @abstract Factory function for IOInterruptEventSources creation and initialisation. 119 @param owner Owning client of the new event source. 120 @param action 'C' Function to call when something happens. 121 @param provider IOService that represents the interrupt source. Defaults to 0. When no provider is defined the event source assumes that the client will in some manner call the interruptOccured method explicitly. This will start the ball rolling for safe delivery of asynchronous event's into the driver. 122 @param intIndex The index of the interrupt within the provider's interrupt sources. Defaults to 0, i.e. the first interrupt in the provider. 123 @result A new interrupt event source if successfully created and initialised, 0 otherwise. */ 124 static IOInterruptEventSource * 125 interruptEventSource(OSObject *owner, 126 Action action, 127 IOService *provider = 0, 128 int intIndex = 0); 129 130/*! @function init 131 @abstract Primary initialiser for the IOInterruptEventSource class. 132 @param owner Owning client of the new event source. 133 @param action 'C' Function to call when something happens. 134 @param provider IOService that represents the interrupt source. Defaults to 0. When no provider is defined the event source assumes that the client will in some manner call the interruptOccured method explicitly. This will start the ball rolling for safe delivery of asynchronous event's into the driver. 135 @param intIndex The index of the interrupt within the provider's interrupt sources. Defaults to 0, i.e. the first interrupt in the provider. 136 @result true if the inherited classes and this instance initialise 137successfully. */ 138 virtual bool init(OSObject *owner, 139 Action action, 140 IOService *provider = 0, 141 int intIndex = 0); 142 143/*! @function enable 144 @abstract Enable event source. 145 @discussion A subclass implementation is expected to respect the enabled 146state when checkForWork is called. Calling this function will cause the 147work-loop to be signalled so that a checkForWork is performed. */ 148 virtual void enable(); 149 150/*! @function disable 151 @abstract Disable event source. 152 @discussion A subclass implementation is expected to respect the enabled 153state when checkForWork is called. */ 154 virtual void disable(); 155 156/*! @function getProvider 157 @abstract Get'ter for $link provider variable. 158 @result value of provider. */ 159 virtual const IOService *getProvider() const; 160 161/*! @function getIntIndex 162 @abstract Get'ter for $link intIndex interrupt index variable. 163 @result value of intIndex. */ 164 virtual int getIntIndex() const; 165 166/*! @function getAutoDisable 167 @abstract Get'ter for $link autoDisable variable. 168 @result value of autoDisable. */ 169 virtual bool getAutoDisable() const; 170 171/*! @function interruptOccurred 172 @abstract Functions that get called by the interrupt controller. See $link IOService::registerInterrupt 173 @param nub Where did the interrupt originate from 174 @param ind What is this interrupts index within 'nub'. */ 175 virtual void interruptOccurred(void *, IOService *nub, int ind); 176 177/*! @function normalInterruptOccurred 178 @abstract Functions that get called by the interrupt controller.See $link IOService::registerInterrupt 179 @param nub Where did the interrupt originate from 180 @param ind What is this interrupts index within 'nub'. */ 181 virtual void normalInterruptOccurred(void *, IOService *nub, int ind); 182 183/*! @function disableInterruptOccurred 184 @abstract Functions that get called by the interrupt controller.See $link IOService::registerInterrupt 185 @param nub Where did the interrupt originate from 186 @param ind What is this interrupts index within 'nub'. */ 187 virtual void disableInterruptOccurred(void *, IOService *nub, int ind); 188 189private: 190 OSMetaClassDeclareReservedUnused(IOInterruptEventSource, 0); 191 OSMetaClassDeclareReservedUnused(IOInterruptEventSource, 1); 192 OSMetaClassDeclareReservedUnused(IOInterruptEventSource, 2); 193 OSMetaClassDeclareReservedUnused(IOInterruptEventSource, 3); 194 OSMetaClassDeclareReservedUnused(IOInterruptEventSource, 4); 195 OSMetaClassDeclareReservedUnused(IOInterruptEventSource, 5); 196 OSMetaClassDeclareReservedUnused(IOInterruptEventSource, 6); 197 OSMetaClassDeclareReservedUnused(IOInterruptEventSource, 7); 198}; 199 200#endif /* !_IOKIT_IOINTERRUPTEVENTSOURCE_H */ 201