1/*
2 * <linux/usb/audio.h> -- USB Audio definitions.
3 *
4 * Copyright (C) 2006 Thumtronics Pty Ltd.
5 * Developed for Thumtronics by Grey Innovation
6 * Ben Williamson <ben.williamson@greyinnovation.com>
7 *
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.
10 *
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:
14 *
15 * http://www.usb.org/developers/devclass_docs/audio10.pdf
16 */
17
18#ifndef __LINUX_USB_AUDIO_H
19#define __LINUX_USB_AUDIO_H
20
21#include <linux/types.h>
22
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
27
28/* 4.3.2  Class-Specific AC Interface Descriptor */
29struct 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));
38
39#define USB_DT_AC_HEADER_SIZE(n)	(8+(n))
40
41/* As above, but more useful for defining your own descriptors: */
42#define DECLARE_USB_AC_HEADER_DESCRIPTOR(n) 			\
43struct usb_ac_header_descriptor_##n {				\
44	__u8  bLength;						\
45	__u8  bDescriptorType;					\
46	__u8  bDescriptorSubtype;				\
47	__le16 bcdADC;						\
48	__le16 wTotalLength;					\
49	__u8  bInCollection;					\
50	__u8  baInterfaceNr[n];					\
51} __attribute__ ((packed))
52
53#endif
54