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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_ep_enable</title><meta name="generator" content="DocBook XSL Stylesheets V1.75.2" /><link rel="home" href="index.html" title="USB Gadget API for Linux" /><link rel="up" href="ch03s03.html" title="Core Objects and Methods" /><link rel="prev" href="re17.html" title="struct usb_ep" /><link rel="next" href="re19.html" title="usb_ep_disable" /></head><body><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center"><span>usb_ep_enable</span></th></tr><tr><td width="20%" align="left"><a accesskey="p" href="re17.html">Prev</a> </td><th width="60%" align="center">Core Objects and Methods</th><td width="20%" align="right"> <a accesskey="n" href="re19.html">Next</a></td></tr></table><hr /></div><div class="refentry" title="usb_ep_enable"><a id="API-usb-ep-enable"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>usb_ep_enable —
configure endpoint, making it usable
</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 <b class="fsfunc">usb_ep_enable </b>(</code></td><td>struct usb_ep * <var class="pdparam">ep</var>, </td></tr><tr><td> </td><td>const struct usb_endpoint_descriptor * <var class="pdparam">desc</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div></div></div><div class="refsect1" title="Arguments"><a id="id2992641"></a><h2>Arguments</h2><div class="variablelist"><dl><dt><span class="term"><em class="parameter"><code>ep</code></em></span></dt><dd><p>
the endpoint being configured. may not be the endpoint named <span class="quote">“<span class="quote">ep0</span>”</span>.
drivers discover endpoints through the ep_list of a usb_gadget.
</p></dd><dt><span class="term"><em class="parameter"><code>desc</code></em></span></dt><dd><p>
descriptor for desired behavior. caller guarantees this pointer
remains valid until the endpoint is disabled; the data byte order
is little-endian (usb-standard).
</p></dd></dl></div></div><div class="refsect1" title="Description"><a id="id2992691"></a><h2>Description</h2><p>
when configurations are set, or when interface settings change, the driver
will enable or disable the relevant endpoints. while it is enabled, an
endpoint may be used for i/o until the driver receives a <code class="function">disconnect</code> from
the host or until the endpoint is disabled.
</p><p>
the ep0 implementation (which calls this routine) must ensure that the
hardware capabilities of each endpoint match the descriptor provided
for it. for example, an endpoint named <span class="quote">“<span class="quote">ep2in-bulk</span>”</span> would be usable
for interrupt transfers as well as bulk, but it likely couldn't be used
for iso transfers or for endpoint 14. some endpoints are fully
configurable, with more generic names like <span class="quote">“<span class="quote">ep-a</span>”</span>. (remember that for
USB, <span class="quote">“<span class="quote">in</span>”</span> means <span class="quote">“<span class="quote">towards the USB master</span>”</span>.)
</p><p>
returns zero, or a negative error code.
</p></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="re17.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="ch03s03.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="re19.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top"><span>struct usb_ep</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_ep_disable</span></td></tr></table></div></body></html>
