1<html><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968"><title>DMA Channels</title><meta name="generator" content="DocBook XSL Stylesheets V1.78.1"><link rel="home" href="index.html" title="The Linux Kernel API"><link rel="up" href="hardware.html" title="Chapter&#160;9.&#160;Hardware Interfaces"><link rel="prev" href="API-request-any-context-irq.html" title="request_any_context_irq"><link rel="next" href="API-request-dma.html" title="request_dma"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">DMA Channels</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="API-request-any-context-irq.html">Prev</a>&#160;</td><th width="60%" align="center">Chapter&#160;9.&#160;Hardware Interfaces</th><td width="20%" align="right">&#160;<a accesskey="n" href="API-request-dma.html">Next</a></td></tr></table><hr></div><div class="sect1"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp1125847108"></a>DMA Channels</h2></div></div></div><div class="toc"><dl class="toc"><dt><span class="refentrytitle"><a href="API-request-dma.html"><span class="phrase">request_dma</span></a></span><span class="refpurpose"> &#8212; 
2  request and reserve a system DMA channel
3 </span></dt><dt><span class="refentrytitle"><a href="API-free-dma.html"><span class="phrase">free_dma</span></a></span><span class="refpurpose"> &#8212; 
4     free a reserved system DMA channel
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