1<html><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968"><title>device_find_child</title><meta name="generator" content="DocBook XSL Stylesheets V1.78.1"><link rel="home" href="index.html" title="Linux Device Drivers"><link rel="up" href="ch02s02.html" title="Device Drivers Base"><link rel="prev" href="API-device-for-each-child.html" title="device_for_each_child"><link rel="next" href="API---root-device-register.html" title="__root_device_register"></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"><span class="phrase">device_find_child</span></th></tr><tr><td width="20%" align="left"><a accesskey="p" href="API-device-for-each-child.html">Prev</a>&#160;</td><th width="60%" align="center">Device Drivers Base</th><td width="20%" align="right">&#160;<a accesskey="n" href="API---root-device-register.html">Next</a></td></tr></table><hr></div><div class="refentry"><a name="API-device-find-child"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>device_find_child &#8212; 
2     device iterator for locating a particular device.
3 </p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><div class="funcsynopsis"><table border="0" class="funcprototype-table" summary="Function synopsis" style="cellspacing: 0; cellpadding: 0;"><tr><td><code class="funcdef">struct device * <b class="fsfunc">device_find_child </b>(</code></td><td>struct device * <var class="pdparam">parent</var>, </td></tr><tr><td>&#160;</td><td>void * <var class="pdparam">data</var>, </td></tr><tr><td>&#160;</td><td>int (*<var class="pdparam">match</var>)
4     <code>(</code>struct device *dev, void *data<code>)</code><code>)</code>;</td></tr></table><div class="funcprototype-spacer">&#160;</div></div></div><div class="refsect1"><a name="idp1109374308"></a><h2>Arguments</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><em class="parameter"><code>parent</code></em></span></dt><dd><p>
5     parent struct device
6    </p></dd><dt><span class="term"><em class="parameter"><code>data</code></em></span></dt><dd><p>
7     Data to pass to match function
8    </p></dd><dt><span class="term"><em class="parameter"><code>match</code></em></span></dt><dd><p>
9     Callback function to check device
10    </p></dd></dl></div></div><div class="refsect1"><a name="idp1109377996"></a><h2>Description</h2><p>
11   This is similar to the <code class="function">device_for_each_child</code> function above, but it
12   returns a reference to a device that is 'found' for later use, as
13   determined by the <em class="parameter"><code>match</code></em> callback.
14   </p><p>
15
16   The callback should return 0 if the device doesn't match and non-zero
17   if it does.  If the callback returns non-zero and a reference to the
18   current device can be obtained, this function will return to the caller
19   and not iterate over any more devices.
20</p></div><div class="refsect1"><a name="idp1109379868"></a><h2>NOTE</h2><p>
21   you will need to drop the reference with <code class="function">put_device</code> after use.
22</p></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="API-device-for-each-child.html">Prev</a>&#160;</td><td width="20%" align="center"><a accesskey="u" href="ch02s02.html">Up</a></td><td width="40%" align="right">&#160;<a accesskey="n" href="API---root-device-register.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top"><span class="phrase">device_for_each_child</span>&#160;</td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top">&#160;<span class="phrase">__root_device_register</span></td></tr></table></div></body></html>
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