include/linux/usb/audio.h

   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 */
  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));
  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)                     \
  43 struct 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 /* __LINUX_USB_AUDIO_H */