1<html><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968"><title>class_for_each_device</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-class-dev-iter-exit.html" title="class_dev_iter_exit"><link rel="next" href="API-class-find-device.html" title="class_find_device"></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">class_for_each_device</span></th></tr><tr><td width="20%" align="left"><a accesskey="p" href="API-class-dev-iter-exit.html">Prev</a> </td><th width="60%" align="center">Device Drivers Base</th><td width="20%" align="right"> <a accesskey="n" href="API-class-find-device.html">Next</a></td></tr></table><hr></div><div class="refentry"><a name="API-class-for-each-device"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>class_for_each_device — 2 device iterator 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">int <b class="fsfunc">class_for_each_device </b>(</code></td><td>struct class * <var class="pdparam">class</var>, </td></tr><tr><td> </td><td>struct device * <var class="pdparam">start</var>, </td></tr><tr><td> </td><td>void * <var class="pdparam">data</var>, </td></tr><tr><td> </td><td>int (*<var class="pdparam">fn</var>) 4 <code>(</code>struct device *, void *<code>)</code><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div></div></div><div class="refsect1"><a name="idp1109575068"></a><h2>Arguments</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><em class="parameter"><code>class</code></em></span></dt><dd><p> 5 the class we're iterating 6 </p></dd><dt><span class="term"><em class="parameter"><code>start</code></em></span></dt><dd><p> 7 the device to start with in the list, if any. 8 </p></dd><dt><span class="term"><em class="parameter"><code>data</code></em></span></dt><dd><p> 9 data for the callback 10 </p></dd><dt><span class="term"><em class="parameter"><code>fn</code></em></span></dt><dd><p> 11 function to be called for each device 12 </p></dd></dl></div></div><div class="refsect1"><a name="idp1109579788"></a><h2>Description</h2><p> 13 Iterate over <em class="parameter"><code>class</code></em>'s list of devices, and call <em class="parameter"><code>fn</code></em> for each, 14 passing it <em class="parameter"><code>data</code></em>. If <em class="parameter"><code>start</code></em> is set, the list iteration will start 15 there, otherwise if it is NULL, the iteration starts at the 16 beginning of the list. 17 </p><p> 18 19 We check the return of <em class="parameter"><code>fn</code></em> each time. If it returns anything 20 other than 0, we break out and return that value. 21 </p><p> 22 23 <em class="parameter"><code>fn</code></em> is allowed to do anything including calling back into class 24 code. There's no locking restriction. 25</p></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="API-class-dev-iter-exit.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="ch02s02.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="API-class-find-device.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top"><span class="phrase">class_dev_iter_exit</span> </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> <span class="phrase">class_find_device</span></td></tr></table></div></body></html> 26