1<html><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968"><title>usb_string_ids_n</title><meta name="generator" content="DocBook XSL Stylesheets V1.78.1"><link rel="home" href="index.html" title="USB Gadget API for Linux"><link rel="up" href="composite.html" title="Composite Device Framework"><link rel="prev" href="API-usb-gstrings-attach.html" title="usb_gstrings_attach"><link rel="next" href="API-usb-composite-probe.html" title="usb_composite_probe"></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">usb_string_ids_n</span></th></tr><tr><td width="20%" align="left"><a accesskey="p" href="API-usb-gstrings-attach.html">Prev</a>&#160;</td><th width="60%" align="center">Composite Device Framework</th><td width="20%" align="right">&#160;<a accesskey="n" href="API-usb-composite-probe.html">Next</a></td></tr></table><hr></div><div class="refentry"><a name="API-usb-string-ids-n"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>usb_string_ids_n &#8212; 
2     allocate unused string IDs in batch
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">usb_string_ids_n </b>(</code></td><td>struct usb_composite_dev * <var class="pdparam">c</var>, </td></tr><tr><td>&#160;</td><td>unsigned <var class="pdparam">n</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer">&#160;</div></div></div><div class="refsect1"><a name="idp1124482796"></a><h2>Arguments</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><em class="parameter"><code>c</code></em></span></dt><dd><p>
4     the device whose string descriptor IDs are being allocated
5    </p></dd><dt><span class="term"><em class="parameter"><code>n</code></em></span></dt><dd><p>
6     number of string IDs to allocate
7    </p></dd></dl></div></div><div class="refsect1"><a name="idp1124485404"></a><h2>Context</h2><p>
8   single threaded during gadget setup
9</p></div><div class="refsect1"><a name="idp1124486028"></a><h2>Description</h2><p>
10   Returns the first requested ID.  This ID and next <em class="parameter"><code>n</code></em>-1 IDs are now
11   valid IDs.  At least provided that <em class="parameter"><code>n</code></em> is non-zero because if it
12   is, returns last requested ID which is now very useful information.
13   </p><p>
14
15   <em class="parameter"><code>usb_string_ids_n</code></em>() is called from <code class="function">bind</code> callbacks to allocate
16   string IDs.  Drivers for functions, configurations, or gadgets will
17   then store that ID in the appropriate descriptors and string table.
18   </p><p>
19
20   All string identifier should be allocated using this,
21   <em class="parameter"><code>usb_string_id</code></em>() or <em class="parameter"><code>usb_string_ids_n</code></em>() routine, to ensure that for
22   example different functions don't wrongly assign different meanings
23   to the same identifier.
24</p></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="API-usb-gstrings-attach.html">Prev</a>&#160;</td><td width="20%" align="center"><a accesskey="u" href="composite.html">Up</a></td><td width="40%" align="right">&#160;<a accesskey="n" href="API-usb-composite-probe.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top"><span class="phrase">usb_gstrings_attach</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">usb_composite_probe</span></td></tr></table></div></body></html>
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