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<concept id="GUID-F8AC78AB-D1D8-4342-A773-9804723989D0" xml:lang="en"><title>GPIO

Implementation Guide</title><shortdesc>Provides information to create a platform specific implementation

of the Symbian platform generic GPIO interface. </shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>

<p>GPIO provides new implementation infrastructure that platforms may choose

to use when implementing the GPIO programming interface.  Platforms can update

their GPIO support to use this. The driver programming interfaces also provided

in this guide You can provide support for GPIO hardware in a board support

package by implementing the interface that Symbian platform defines in the

GPIO class.</p>

<section id="GUID-BCDC252F-7466-4391-9E42-26D173FA4E50">       <title>Required

background</title>       <p>Before you start, you must know the following:</p><ul>

<li><p>Platform implementation.</p></li>

<li><p>GPIO concepts and terminology.</p></li>

<li><p>Architecture of the platform on which you are implementing.</p></li>

<li><p>C++ signature of the functions you are implementing.</p></li>

</ul>     </section>

<section id="GUID-3F5A1CB6-7717-48A3-B63A-CB843D7F7054"><title>Implementation</title><p> To

provide a consistent interface to clients of the GPIO class, your implementation

must return certain error codes in certain specified conditions. The functions

are mainly categorized into:</p><ul>

<li><p><xref href="GUID-9AD35939-26DD-4A42-8727-D0FD2F45B6DE.dita">Pin mode functions</xref></p></li>

<li><p><xref href="GUID-DA8526FB-5789-4CB6-9A92-754E39C52E3B.dita">Pin direction

functions</xref></p></li>

<li><p><xref href="GUID-96CA3539-8C01-4EFE-8DE8-1F88C0607E02.dita">Pin bias functions</xref></p></li>

<li><p><xref href="GUID-D948E88E-D123-40A5-A2CD-CF3D13581CC9.dita">Pin idle functions</xref></p></li>

<li><p><xref href="GUID-153E6611-D7BC-4B5B-A5C4-38BCA16C1635.dita">Interrupt functions</xref></p></li>

<li><p><xref href="GUID-74FE6572-14B9-4B94-8DD0-803DA21D14A3.dita">Wakeup functions</xref></p></li>

<li><p><xref href="GUID-BAE9F3A8-E232-491B-9F29-E2BF7298F9EA.dita">Trigger functions.</xref></p></li>

<li><p><xref href="GUID-9E7F8D0B-2B0E-41CC-BCDF-6B01B56CEF37.dita">Debounce functions</xref></p></li>

<li><p><xref href="GUID-90E2A645-56B0-4FC2-AE92-CD72FEC23AE6.dita">Input and Output

functions</xref></p></li>

</ul><p> The details of the functions, modes, associated required return values

and their usage are described in their respective sections.</p><note> Implementation

of the functions communicates with your GPIO hardware will be specific to

the hardware you are using.</note></section>

<section id="GUID-0D4BD293-329B-4549-A36B-A428FE1BE57A"><title>See Also</title><p><xref href="GUID-A5D862E4-3EC3-45C0-B635-23A02E5BB11F.dita">GPIO Overview</xref></p></section>

</conbody></concept>