/** @defgroup usb_audio_defines USB Audio Type Definitions
@brief Defined Constants and Types for the USB Audio Type Definitions
@ingroup USB_defines
@version 1.0.0
@author @htmlonly © @endhtmlonly 2014
Daniel Thompson
Seb Holzapfel
@date 19 April 2014
LGPL License Terms @ref lgpl_license
*/
/*
* This file is part of the libopencm3 project.
*
* Copyright (C) 2014 Daniel Thompson
* Copyright (C) 2018 Seb Holzapfel
*
* This library is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library. If not, see .
*/
/**@{*/
#ifndef LIBOPENCM3_USB_AUDIO_H
#define LIBOPENCM3_USB_AUDIO_H
#include
/*
* Definitions from the USB_AUDIO_ or usb_audio_ namespace come from:
* "Universal Serial Bus Class Definitions for Audio Devices, Revision 1.0"
*/
/* Table A-1: Audio Interface Class Code */
#define USB_CLASS_AUDIO 0x01
/* Table A-2: Audio Interface Subclass Codes */
#define USB_AUDIO_SUBCLASS_UNDEFINED 0x00
#define USB_AUDIO_SUBCLASS_CONTROL 0x01
#define USB_AUDIO_SUBCLASS_AUDIOSTREAMING 0x02
#define USB_AUDIO_SUBCLASS_MIDISTREAMING 0x03
/* Table A-4: Audio Class-specific Descriptor Types */
#define USB_AUDIO_DT_CS_UNDEFINED 0x20
#define USB_AUDIO_DT_CS_DEVICE 0x21
#define USB_AUDIO_DT_CS_CONFIGURATION 0x22
#define USB_AUDIO_DT_CS_STRING 0x23
#define USB_AUDIO_DT_CS_INTERFACE 0x24
#define USB_AUDIO_DT_CS_ENDPOINT 0x25
/* Table A-5: Audio Class-Specific AC Interface Descriptor Subtypes */
#define USB_AUDIO_TYPE_AC_DESCRIPTOR_UNDEFINED 0x00
#define USB_AUDIO_TYPE_HEADER 0x01
#define USB_AUDIO_TYPE_INPUT_TERMINAL 0x02
#define USB_AUDIO_TYPE_OUTPUT_TERMINAL 0x03
#define USB_AUDIO_TYPE_MIXER_UNIT 0x04
#define USB_AUDIO_TYPE_SELECTOR_UNIT 0x05
#define USB_AUDIO_TYPE_FEATURE_UNIT 0x06
#define USB_AUDIO_TYPE_PROCESSING_UNIT 0x07
#define USB_AUDIO_TYPE_EXTENSION_UNIT 0x08
/* Table 4-2: Class-Specific AC Interface Header Descriptor (head) */
struct usb_audio_header_descriptor_head {
uint8_t bLength;
uint8_t bDescriptorType;
uint8_t bDescriptorSubtype;
uint16_t bcdADC;
uint16_t wTotalLength;
uint8_t binCollection;
/* ... */
} __attribute__((packed));
/* Table 4-2: Class-Specific AC Interface Header Descriptor (body) */
struct usb_audio_header_descriptor_body {
/* ... */
uint8_t baInterfaceNr;
} __attribute__((packed));
/* Table 4-3: Input Terminal Descriptor */
struct usb_audio_input_terminal_descriptor {
uint8_t bLength;
uint8_t bDescriptorType;
uint8_t bDescriptorSubtype;
uint8_t bTerminalID;
uint16_t wTerminalType;
uint8_t bAssocTerminal;
uint8_t bNrChannels;
uint16_t wChannelConfig;
uint8_t iChannelNames;
uint8_t iTerminal;
} __attribute__((packed));
/* Table 4-3: Output Terminal Descriptor */
struct usb_audio_output_terminal_descriptor {
uint8_t bLength;
uint8_t bDescriptorType;
uint8_t bDescriptorSubtype;
uint8_t bTerminalID;
uint16_t wTerminalType;
uint8_t bAssocTerminal;
uint8_t bSourceID;
uint8_t iTerminal;
} __attribute__((packed));
/* Table 4-7: Feature Unit Descriptor (head) */
struct usb_audio_feature_unit_descriptor_head {
uint8_t bLength;
uint8_t bDescriptorType;
uint8_t bDescriptorSubtype;
uint8_t bUnitID;
uint8_t bSourceID;
uint8_t bControlSize;
uint16_t bmaControlMaster; /* device can assume 16-bit, given highest
* defined bit in spec is bit #9.
* (it is thus required bControlSize=2) */
/* ... */
} __attribute__((packed));
/* Table 4-7: Feature Unit Descriptor (body) */
struct usb_audio_feature_unit_descriptor_body {
/* ... */
uint16_t bmaControl;
/* ... */
} __attribute__((packed));
/* Table 4-7: Feature Unit Descriptor (tail) */
struct usb_audio_feature_unit_descriptor_tail {
/* ... */
uint8_t iFeature;
} __attribute__((packed));
/* Table 4-7: Feature Unit Descriptor (2-channel)
*
* This structure is a convenience covering the (common) case where
* there are 2 channels associated with the feature unit
*/
struct usb_audio_feature_unit_descriptor_2ch {
struct usb_audio_feature_unit_descriptor_head head;
struct usb_audio_feature_unit_descriptor_body channel_control[2];
struct usb_audio_feature_unit_descriptor_tail tail;
} __attribute__((packed));
/* Table 4-19: Class-Specific AS Interface Descriptor */
struct usb_audio_stream_interface_descriptor {
uint8_t bLength;
uint8_t bDescriptorType;
uint8_t bDescriptorSubtype;
uint8_t bTerminalLink;
uint8_t bDelay;
uint16_t wFormatTag;
} __attribute__((packed));
/* Table 4-20: Standard AS Isochronous Audio Data Endpoint Descriptor */
struct usb_audio_stream_endpoint_descriptor {
uint8_t bLength;
uint8_t bDescriptorType;
uint8_t bEndpointAddress;
uint8_t bmAttributes;
uint16_t wMaxPacketSize;
uint8_t bInterval;
uint8_t bRefresh;
uint8_t bSynchAddress;
} __attribute__((packed));
/* Table 4-21: Class-Specific AS Isochronous Audio Data Endpoint Descriptor */
struct usb_audio_stream_audio_endpoint_descriptor {
uint8_t bLength;
uint8_t bDescriptorType;
uint8_t bDescriptorSubtype;
uint8_t bmAttributes;
uint8_t bLockDelayUnits;
uint16_t wLockDelay;
} __attribute__((packed));
/*
* Definitions from the USB_AUDIO_FORMAT_ or usb_audio_format_ namespace come from:
* "Universal Serial Bus Device Class Definition for Audio Data Formats, Revision 1.0"
*/
/* Table 2-1: Type I Format Type Descriptor (head) */
struct usb_audio_format_type1_descriptor_head {
uint8_t bLength;
uint8_t bDescriptorType;
uint8_t bDescriptorSubtype;
uint8_t bFormatType;
uint8_t bNrChannels;
uint8_t bSubFrameSize;
uint8_t bBitResolution;
uint8_t bSamFreqType;
/* ... */
} __attribute__((packed));
/* Table 2-2: Continuous Sampling Frequency */
struct usb_audio_format_continuous_sampling_frequency {
/* ... */
uint32_t tLowerSamFreq : 24;
uint32_t tUpperSamFreq : 24;
} __attribute__((packed));
/* Table 2-3: Discrete Number of Sampling Frequencies */
struct usb_audio_format_discrete_sampling_frequency {
/* ... */
uint32_t tSamFreq : 24;
} __attribute__((packed));
/* Table 2-1: Type I Format Type Descriptor (1 sampling frequency)
*
* This structure is a convenience covering the (common) case where
* only 1 discrete sampling frequency is used
*/
struct usb_audio_format_type1_descriptor_1freq {
struct usb_audio_format_type1_descriptor_head head;
struct usb_audio_format_discrete_sampling_frequency freqs[1];
} __attribute__((packed));
#endif
/**@}*/