Place generic USB header and source files into the documentation tree.

lib/usb/usb_private.h

@@ -1,3 +1,18 @@
+/** @defgroup usb_private_defines USB Private Structures
+
+@brief <b>Defined Constants and Types for the USB Private Structures</b>
+
+@ingroup USB_defines
+
+@version 1.0.0
+
+@author @htmlonly &copy; @endhtmlonly 2010 Gareth McMullin <gareth@blacksphere.co.nz>
+
+@date 10 March 2013
+
+LGPL License Terms @ref lgpl_license
+*/
+
 /*
  * This file is part of the libopencm3 project.
  *
@@ -17,6 +32,8 @@
  * along with this library.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+/**@{*/
+
 #ifndef __USB_PRIVATE_H
 #define __USB_PRIVATE_H
 
@@ -95,6 +112,9 @@ enum _usbd_transaction {
 	USB_TRANSACTION_SETUP,
 };
 
+/* Do not appear to belong to the API, so are omitted from docs */
+/**@}*/
+
 void _usbd_control_in(usbd_device *usbd_dev, u8 ea);
 void _usbd_control_out(usbd_device *usbd_dev, u8 ea);
 void _usbd_control_setup(usbd_device *usbd_dev, u8 ea);
@@ -135,3 +155,4 @@ struct _usbd_driver {
 };
 
 #endif
+