iPXE
cdc.c
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00001 /*
00002  * Copyright (C) 2015 Michael Brown <mbrown@fensystems.co.uk>.
00003  *
00004  * This program is free software; you can redistribute it and/or
00005  * modify it under the terms of the GNU General Public License as
00006  * published by the Free Software Foundation; either version 2 of the
00007  * License, or (at your option) any later version.
00008  *
00009  * This program is distributed in the hope that it will be useful, but
00010  * WITHOUT ANY WARRANTY; without even the implied warranty of
00011  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00012  * General Public License for more details.
00013  *
00014  * You should have received a copy of the GNU General Public License
00015  * along with this program; if not, write to the Free Software
00016  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
00017  * 02110-1301, USA.
00018  *
00019  * You can also choose to distribute this program under the terms of
00020  * the Unmodified Binary Distribution Licence (as given in the file
00021  * COPYING.UBDL), provided that you have satisfied its requirements.
00022  */
00023 
00024 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
00025 
00026 #include <stddef.h>
00027 #include <ipxe/usb.h>
00028 #include <ipxe/cdc.h>
00029 
00030 /** @file
00031  *
00032  * USB Communications Device Class (CDC)
00033  *
00034  */
00035 
00036 /**
00037  * Locate CDC union functional descriptor
00038  *
00039  * @v config            Configuration descriptor
00040  * @v interface         Interface descriptor
00041  * @ret desc            Union functional descriptor, or NULL if not found
00042  */
00043 struct cdc_union_descriptor *
00044 cdc_union_descriptor ( struct usb_configuration_descriptor *config,
00045                        struct usb_interface_descriptor *interface ) {
00046         struct cdc_union_descriptor *desc;
00047 
00048         for_each_interface_descriptor ( desc, config, interface ) {
00049                 if ( ( desc->header.type == USB_CS_INTERFACE_DESCRIPTOR ) &&
00050                      ( desc->subtype == CDC_SUBTYPE_UNION ) )
00051                         return desc;
00052         }
00053         return NULL;
00054 }