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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>Composite Device Framework</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="ch03.html" title="Chapter 3. Kernel Mode Gadget API" /><link rel="prev" href="re51.html" title="usb_find_endpoint" /><link rel="next" href="re52.html" title="struct usb_function" /></head><body><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Composite Device Framework</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="re51.html">Prev</a> </td><th width="60%" align="center">Chapter 3. Kernel Mode Gadget API</th><td width="20%" align="right"> <a accesskey="n" href="re52.html">Next</a></td></tr></table><hr /></div><div class="sect1" title="Composite Device Framework"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="composite"></a>Composite Device Framework</h2></div></div></div><div class="toc"><dl><dt><span class="refentrytitle"><a href="re52.html"><span>struct usb_function</span></a></span><span class="refpurpose"> —
describes one function of a configuration
</span></dt><dt><span class="refentrytitle"><a href="re53.html"><span>ep_choose</span></a></span><span class="refpurpose"> —
select descriptor endpoint at current device speed
</span></dt><dt><span class="refentrytitle"><a href="re54.html"><span>struct usb_configuration</span></a></span><span class="refpurpose"> —
represents one gadget configuration
</span></dt><dt><span class="refentrytitle"><a href="re55.html"><span>struct usb_composite_driver</span></a></span><span class="refpurpose"> —
groups configurations into a gadget
</span></dt><dt><span class="refentrytitle"><a href="re56.html"><span>struct usb_composite_dev</span></a></span><span class="refpurpose"> —
represents one composite usb gadget
</span></dt><dt><span class="refentrytitle"><a href="re57.html"><span>usb_add_function</span></a></span><span class="refpurpose"> —
add a function to a configuration
</span></dt><dt><span class="refentrytitle"><a href="re58.html"><span>usb_function_deactivate</span></a></span><span class="refpurpose"> —
prevent function and gadget enumeration
</span></dt><dt><span class="refentrytitle"><a href="re59.html"><span>usb_function_activate</span></a></span><span class="refpurpose"> —
allow function and gadget enumeration
</span></dt><dt><span class="refentrytitle"><a href="re60.html"><span>usb_interface_id</span></a></span><span class="refpurpose"> —
allocate an unused interface ID
</span></dt><dt><span class="refentrytitle"><a href="re61.html"><span>usb_add_config</span></a></span><span class="refpurpose"> —
add a configuration to a device.
</span></dt><dt><span class="refentrytitle"><a href="re62.html"><span>usb_string_id</span></a></span><span class="refpurpose"> —
allocate an unused string ID
</span></dt><dt><span class="refentrytitle"><a href="re63.html"><span>usb_composite_register</span></a></span><span class="refpurpose"> —
register a composite driver
</span></dt><dt><span class="refentrytitle"><a href="re64.html"><span>usb_composite_unregister</span></a></span><span class="refpurpose"> —
unregister a composite driver
</span></dt></dl></div><p>The core API is sufficient for writing drivers for composite
USB devices (with more than one function in a given configuration),
and also multi-configuration devices (also more than one function,
but not necessarily sharing a given configuration).
There is however an optional framework which makes it easier to
reuse and combine functions.
</p><p>Devices using this framework provide a <span class="emphasis"><em>struct
usb_composite_driver</em></span>, which in turn provides one or
more <span class="emphasis"><em>struct usb_configuration</em></span> instances.
Each such configuration includes at least one
<span class="emphasis"><em>struct usb_function</em></span>, which packages a user
visible role such as "network link" or "mass storage device".
Management functions may also exist, such as "Device Firmware
Upgrade".
</p></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="re51.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="ch03.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="re52.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top"><span>usb_find_endpoint</span> </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> <span>struct usb_function</span></td></tr></table></div></body></html>
