2 * <linux/usb/audio.h> -- USB Audio definitions.
4 * Copyright (C) 2006 Thumtronics Pty Ltd.
5 * Developed for Thumtronics by Grey Innovation
6 * Ben Williamson <ben.williamson@greyinnovation.com>
8 * This software is distributed under the terms of the GNU General Public
9 * License ("GPL") version 2, as published by the Free Software Foundation.
11 * This file holds USB constants and structures defined
12 * by the USB Device Class Definition for Audio Devices.
13 * Comments below reference relevant sections of that document:
15 * http://www.usb.org/developers/devclass_docs/audio10.pdf
18 #ifndef __LINUX_USB_AUDIO_H
19 #define __LINUX_USB_AUDIO_H
21 #include <linux/types.h>
23 /* A.2 Audio Interface Subclass Codes */
24 #define USB_SUBCLASS_AUDIOCONTROL 0x01
25 #define USB_SUBCLASS_AUDIOSTREAMING 0x02
26 #define USB_SUBCLASS_MIDISTREAMING 0x03
28 /* 4.3.2 Class-Specific AC Interface Descriptor */
29 struct usb_ac_header_descriptor {
30 __u8 bLength; /* 8+n */
31 __u8 bDescriptorType; /* USB_DT_CS_INTERFACE */
32 __u8 bDescriptorSubtype; /* USB_MS_HEADER */
33 __le16 bcdADC; /* 0x0100 */
34 __le16 wTotalLength; /* includes Unit and Terminal desc. */
35 __u8 bInCollection; /* n */
36 __u8 baInterfaceNr[]; /* [n] */
37 } __attribute__ ((packed));
39 #define USB_DT_AC_HEADER_SIZE(n) (8+(n))
41 /* As above, but more useful for defining your own descriptors: */
42 #define DECLARE_USB_AC_HEADER_DESCRIPTOR(n) \
43 struct usb_ac_header_descriptor_##n { \
45 __u8 bDescriptorType; \
46 __u8 bDescriptorSubtype; \
48 __le16 wTotalLength; \
50 __u8 baInterfaceNr[n]; \
51 } __attribute__ ((packed))
53 #endif /* __LINUX_USB_AUDIO_H */