author | Graeme Price <GRAEME.PRICE@NOKIA.COM> |
Fri, 15 Oct 2010 14:32:18 +0100 | |
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307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
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<?xml version="1.0" encoding="utf-8"?> |
307f4279f433
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Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
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<!-- Copyright (c) 2007-2010 Nokia Corporation and/or its subsidiary(-ies) All rights reserved. --> |
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Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
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<!-- This component and the accompanying materials are made available under the terms of the License |
307f4279f433
Initial contribution of the Adaptation Documentation.
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"Eclipse Public License v1.0" which accompanies this distribution, |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
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and is available at the URL "http://www.eclipse.org/legal/epl-v10.html". --> |
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Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
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<!-- Initial Contributors: |
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Initial contribution of the Adaptation Documentation.
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parents:
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Nokia Corporation - initial contribution. |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
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Contributors: |
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Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
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--> |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
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<!DOCTYPE task |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
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PUBLIC "-//OASIS//DTD DITA Task//EN" "task.dtd"> |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
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<task id="GUID-68446E8E-129C-444A-836A-EF8F56BFE0BC" xml:lang="en"><title>Handling Interrupts</title><shortdesc>Describes how a device driver can use interrupts.</shortdesc><prolog><metadata><keywords/></metadata></prolog><taskbody> |
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Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
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<prereq id="GUID-FCD339E1-54B6-4F3F-9DF0-1C920667001C"><p>The clients |
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of the Interrupt platform service must know the following:<ul> |
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Initial contribution of the Adaptation Documentation.
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<li><p>ISR function</p></li> |
307f4279f433
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<li><p>Interrupt ID</p></li> |
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</ul></p></prereq> |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
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<context id="GUID-3EB0898F-D1ED-47D4-B675-3B8627909384"><p>Interrupts |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
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are sent by hardware to indicate an event has occurred. Interrupts |
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typically cause an Interrupt Service Routine (ISR) to be executed. |
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The Interrupt platform service specifies the interface APIs for setting |
307f4279f433
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Graeme Price <GRAEME.PRICE@NOKIA.COM>
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up the ISRs and connecting them to specific Interrupt IDs. Interrupt |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
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handling is a blocking high priority task and needs to take a minimal |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
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amount of time. While the ISR is executed the kernel will be in an |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
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indeterminate state and this puts restrictions on doing various operations, |
307f4279f433
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Graeme Price <GRAEME.PRICE@NOKIA.COM>
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such as allocating heap storage. </p><p>The device driver provides |
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Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
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an ISR to handle an interrupt and perform the required response to |
307f4279f433
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the events. Symbian platform provides an <xref href="GUID-E7A7083C-97B9-39B9-A147-4A6E314EE3A3.dita"><apiname>Interrupt</apiname></xref> class (implemented by the ASSP) with an API to bind and unbind an |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
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Interrupt ID with an ISR. </p><p>An Interrupt ID is identified by |
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Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
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number, defined as a <codeph>TInt</codeph> type. Typically, the ASSP |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
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layer may define this number for each interrupt in a header file and |
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Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
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export it so that it can be included and used by device drivers. Alternatively, |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
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device drivers may be required to retrieve the appropriate Interrupt |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
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ID from the Hardware Configuration Repository (HCR). The scheme used |
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is implementation dependent.</p></context> |
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<steps id="GUID-4DD07DEC-6017-4237-BE46-1D69E5FBD744-GENID-1-2-1-10-1-5-1-7-1-1-8-1-6-1-3-3"> |
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Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
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<step id="GUID-0CFB6DD5-2309-40EE-84F5-4BC4449BE5BB"><cmd>Call <xref href="GUID-E7A7083C-97B9-39B9-A147-4A6E314EE3A3.dita#GUID-E7A7083C-97B9-39B9-A147-4A6E314EE3A3/GUID-1D846CC9-843D-363B-A0F2-5719B18C0854"><apiname>Interrupt::Bind(TInt, TIsr, TAny*)</apiname></xref> with appropriate Interrupt |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
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ID, ISR and argument to be passed to the ISR. This function binds |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
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the interrupt to the ISR.</cmd> |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
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</step> |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
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<step id="GUID-94DAD86A-0721-4663-A992-8FA001864B5F"><cmd>Assign the |
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Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
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priority to the Interrupt if needed using the <xref href="GUID-E7A7083C-97B9-39B9-A147-4A6E314EE3A3.dita#GUID-E7A7083C-97B9-39B9-A147-4A6E314EE3A3/GUID-975988C3-B9B0-3B82-8CE8-9691E8C54515"><apiname>Interrupt::SetPriority(TInt, |
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TInt)</apiname></xref> function.</cmd> |
307f4279f433
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Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
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</step> |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
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<step id="GUID-E731F5A3-B31F-43A5-BE61-81AA25DCCE3F"><cmd>Enable the |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
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interrupt by calling the <xref href="GUID-E7A7083C-97B9-39B9-A147-4A6E314EE3A3.dita#GUID-E7A7083C-97B9-39B9-A147-4A6E314EE3A3/GUID-23BE001A-205A-33AE-9533-8D50C494211F"><apiname>Interrupt::Enable(TInt)</apiname></xref> function. This function is called when the device driver is ready |
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Graeme Price <GRAEME.PRICE@NOKIA.COM>
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to handle hardware events.</cmd> |
307f4279f433
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Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
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<info><p>An ISR is a static function that will be executed when an |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
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interrupt is received by the interrupt handler. The interrupt handler |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
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executes the ISR that is bound to the received Interrupt ID. It performs |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
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the actions necessary to service the event of the peripheral that |
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Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
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generated the interrupt. The ISR must either remove the condition |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
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that caused the interrupt or call <xref href="GUID-E7A7083C-97B9-39B9-A147-4A6E314EE3A3.dita#GUID-E7A7083C-97B9-39B9-A147-4A6E314EE3A3/GUID-2D14E023-E6ED-39BF-8B31-6FA510957A8A"><apiname>Interrupt::Disable()</apiname></xref> otherwise the machine will hang. The device driver may queue a DFC |
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Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
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within the ISR to perform deferred processing.</p></info> |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
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</step> |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
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<step id="GUID-A088A6FD-67B5-4112-894E-5CE1A2A3BAE6"><cmd>Once the |
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Initial contribution of the Adaptation Documentation.
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DFC processing is completed, it is a good practice to enable the interrupt |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
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if it is disabled, using <xref href="GUID-E7A7083C-97B9-39B9-A147-4A6E314EE3A3.dita#GUID-E7A7083C-97B9-39B9-A147-4A6E314EE3A3/GUID-23BE001A-205A-33AE-9533-8D50C494211F"><apiname>Interrupt::Enable(TInt)</apiname></xref> function. </cmd> |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
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</step> |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
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<step id="GUID-611D449F-C0EB-4027-8E4C-D5CC5D44A29D"><cmd>At the point |
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when the PDD of the device driver gets unloaded, unbind the ISR from |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
parents:
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the specified Interrupt Id using <xref href="GUID-E7A7083C-97B9-39B9-A147-4A6E314EE3A3.dita#GUID-E7A7083C-97B9-39B9-A147-4A6E314EE3A3/GUID-4980B3FF-0C14-3E64-8BB3-E8431CB649F9"><apiname>Interrupt::Unbind(TInt)</apiname></xref> function by passing Interrupt ID as the parameter.</cmd> |
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</step> |
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Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
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</steps> |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
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<result id="GUID-286F666E-B037-4C0E-9A87-02A3CBAB9B8A"><p>The device |
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driver is able to handle interrupts.</p></result> |
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</taskbody><related-links> |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
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<link href="GUID-D0F5D40A-28D2-4A2E-9B40-180537E60F56.dita"><linktext>Interrupt |
307f4279f433
Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
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Client Interface Guide</linktext></link> |
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Graeme Price <GRAEME.PRICE@NOKIA.COM>
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<link href="GUID-654A788A-526A-4C3F-838C-05B09F0D5445.dita"><linktext>Interrupt |
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Initial contribution of the Adaptation Documentation.
Graeme Price <GRAEME.PRICE@NOKIA.COM>
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Technology Guide</linktext></link> |
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</related-links></task> |