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<html xmlns="http://www.w3.org/1999/xhtml"><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 V1.76.1" /><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-string-ids-tab.html" title="usb_string_ids_tab" /><link rel="next" href="API-usb-composite-probe.html" title="usb_composite_probe" /></head><body><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center"><span>usb_string_ids_n</span></th></tr><tr><td width="20%" align="left"><a accesskey="p" href="API-usb-string-ids-tab.html">Prev</a> </td><th width="60%" align="center">Composite Device Framework</th><td width="20%" align="right"> <a accesskey="n" href="API-usb-composite-probe.html">Next</a></td></tr></table><hr /></div><div class="refentry" title="usb_string_ids_n"><a id="API-usb-string-ids-n"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>usb_string_ids_n —
allocate unused string IDs in batch
</p></div><div class="refsynopsisdiv" title="Synopsis"><h2>Synopsis</h2><div class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" class="funcprototype-table"><tr><td><code class="funcdef">int <strong>fsfuncusb_string_ids_n </strong>(</code></td><td>struct usb_composite_dev * <var class="pdparam">c</var>, </td></tr><tr><td> </td><td>unsigned <var class="pdparam">n</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div></div></div><div class="refsect1" title="Arguments"><a id="id3080467"></a><h2>Arguments</h2><div class="variablelist"><dl><dt><span class="term"><em class="parameter"><code>c</code></em></span></dt><dd><p>
the device whose string descriptor IDs are being allocated
</p></dd><dt><span class="term"><em class="parameter"><code>n</code></em></span></dt><dd><p>
number of string IDs to allocate
</p></dd></dl></div></div><div class="refsect1" title="Context"><a id="id3080511"></a><h2>Context</h2><p>
single threaded during gadget setup
</p></div><div class="refsect1" title="Description"><a id="id3080521"></a><h2>Description</h2><p>
Returns the first requested ID. This ID and next <em class="parameter"><code>n</code></em>-1 IDs are now
valid IDs. At least provided that <em class="parameter"><code>n</code></em> is non-zero because if it
is, returns last requested ID which is now very useful information.
</p><p>
<em class="parameter"><code>usb_string_ids_n</code></em>() is called from <code class="function">bind</code> callbacks to allocate
string IDs. Drivers for functions, configurations, or gadgets will
then store that ID in the appropriate descriptors and string table.
</p><p>
All string identifier should be allocated using this,
<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
example different functions don't wrongly assign different meanings
to the same identifier.
</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-string-ids-tab.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="composite.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="API-usb-composite-probe.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top"><span>usb_string_ids_tab</span> </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> <span>usb_composite_probe</span></td></tr></table></div></body></html>
