text: /*
               LUFA Library
       Copyright (C) Dean Camera, 2009.
                
    dean [at] fourwalledcubicle [dot] com
        www.fourwalledcubicle.com
  */
  
  /*
    Copyright 2009  Dean Camera (dean [at] fourwalledcubicle [dot] com)
  
    Permission to use, copy, modify, and distribute this software
    and its documentation for any purpose and without fee is hereby
    granted, provided that the above copyright notice appear in all
    copies and that both that the copyright notice and this
    permission notice and warranty disclaimer appear in supporting
    documentation, and that the name of the author not be used in
    advertising or publicity pertaining to distribution of the
    software without specific, written prior permission.
  
    The author disclaim all warranties with regard to this
    software, including all implied warranties of merchantability
    and fitness.  In no event shall the author be liable for any
    special, indirect or consequential damages or any damages
    whatsoever resulting from loss of use, data or profits, whether
    in an action of contract, negligence or other tortious action,
    arising out of or in connection with the use or performance of
    this software.
  */
  
  /** \file
   *
   *  Header file for Descriptors.c.
   */
   
  #ifndef _DESCRIPTORS_H_
  #define _DESCRIPTORS_H_
  
  	/* Includes: */
  		#include <LUFA/Drivers/USB/USB.h>
  
  		#include <avr/pgmspace.h>
  
  	/* Macros: */
  		/** Descriptor header constant to indicate a Audio class interface descriptor. */
  		#define DTYPE_AudioInterface         0x24
  
  		/** Descriptor header constant to indicate a Audio class endpoint descriptor. */
  		#define DTYPE_AudioEndpoint          0x25
  
  		/** Audio class descriptor subtype value for a Audio class specific header descriptor. */
  		#define DSUBTYPE_Header              0x01
  
  		/** Audio class descriptor subtype value for an Output Terminal Audio class specific descriptor. */
  		#define DSUBTYPE_InputTerminal       0x02
  
  		/** Audio class descriptor subtype value for an Input Terminal Audio class specific descriptor. */
  		#define DSUBTYPE_OutputTerminal      0x03
  
  		/** Audio class descriptor subtype value for a Feature Unit Audio class specific descriptor. */
  		#define DSUBTYPE_FeatureUnit         0x06
  
  		/** Audio class descriptor subtype value for a general Audio class specific descriptor. */
  		#define DSUBTYPE_General             0x01
  
  		/** Audio class descriptor subtype value for an Audio class specific descriptor indicating the format of an audio stream. */
  		#define DSUBTYPE_Format              0x02
  		
  		//@{
  		/** Supported channel mask for an Audio class terminal descriptor. See the Audio class specification for more details. */
  
  		#define CHANNEL_LEFT_FRONT           (1 << 0)
  		#define CHANNEL_RIGHT_FRONT          (1 << 1)
  		#define CHANNEL_CENTER_FRONT         (1 << 2)
  		#define CHANNEL_LOW_FREQ_ENHANCE     (1 << 3)
  		#define CHANNEL_LEFT_SURROUND        (1 << 4)
  		#define CHANNEL_RIGHT_SURROUND       (1 << 5)
  		#define CHANNEL_LEFT_OF_CENTER       (1 << 6)
  		#define CHANNEL_RIGHT_OF_CENTER      (1 << 7)
  		#define CHANNEL_SURROUND             (1 << 8)
  		#define CHANNEL_SIDE_LEFT            (1 << 9)
  		#define CHANNEL_SIDE_RIGHT           (1 << 10)
  		#define CHANNEL_TOP                  (1 << 11)
  		//@}
  
  		//@{
  		/** Supported feature mask for an Audio class feature unit descriptor. See the Audio class specification for more details. */
  
  		#define FEATURE_MUTE                 (1 << 0)
  		#define FEATURE_VOLUME               (1 << 1)
  		#define FEATURE_BASS                 (1 << 2)
  		#define FEATURE_MID                  (1 << 3)
  		#define FEATURE_TREBLE               (1 << 4)
  		#define FEATURE_GRAPHIC_EQUALIZER    (1 << 5)
  		#define FEATURE_AUTOMATIC_GAIN       (1 << 6)
  		#define FEATURE_DELAY                (1 << 7)
  		#define FEATURE_BASS_BOOST           (1 << 8)
  		#define FEATURE_BASS_LOUDNESS        (1 << 9)
  		//@}
  
  		//@{
  		/** Terminal type constant for an Audio class terminal descriptor. See the Audio class specification for more details. */
  		
  		#define TERMINAL_UNDEFINED           0x0100
  		#define TERMINAL_STREAMING           0x0101
  		#define TERMINAL_VENDOR              0x01FF
  		#define TERMINAL_IN_UNDEFINED        0x0200
  		#define TERMINAL_IN_MIC              0x0201
  		#define TERMINAL_IN_DESKTOP_MIC      0x0202
  		#define TERMINAL_IN_PERSONAL_MIC     0x0203
  		#define TERMINAL_IN_OMNIDIR_MIC      0x0204
  		#define TERMINAL_IN_MIC_ARRAY        0x0205
  		#define TERMINAL_IN_PROCESSING_MIC   0x0206
  		#define TERMINAL_IN_OUT_UNDEFINED    0x0300
  		#define TERMINAL_OUT_SPEAKER         0x0301
  		#define TERMINAL_OUT_HEADPHONES      0x0302
  		#define TERMINAL_OUT_HEAD_MOUNTED    0x0303
  		#define TERMINAL_OUT_DESKTOP         0x0304
  		#define TERMINAL_OUT_ROOM            0x0305
  		#define TERMINAL_OUT_COMMUNICATION   0x0306
  		#define TERMINAL_OUT_LOWFREQ         0x0307
  		//@}
  
  		/** Convenience macro, to fill a 24-bit AudioSampleFreq_t structure with the given sample rate as a 24-bit number.
  		 *
  		 *  \param[in] freq  Required audio sampling frequency in HZ
  		 */
  		#define SAMPLE_FREQ(freq)  {LowWord: ((uint32_t)(freq) & 0x00FFFF), HighByte: (((uint32_t)(freq) >> 16) & 0x0000FF)}
  		
  		/** Mask for the attributes parameter of an Audio class specific Endpoint descriptor, indicating that the endpoint
  		 *  accepts only filled endpoint packets of audio samples.
  		 */
  		#define EP_ACCEPTS_ONLY_FULL_PACKETS (1 << 7)
  
  		/** Mask for the attributes parameter of an Audio class specific Endpoint descriptor, indicating that the endpoint
  		 *  will accept partially filled endpoint packets of audio samples.
  		 */
  		#define EP_ACCEPTS_SMALL_PACKETS     (0 << 7)
  
  		/** Endpoint number of the Audio isochronous streaming data endpoint. */
  		#define AUDIO_STREAM_EPNUM           1
  		
  		/** Endpoint size in bytes of the Audio isochronous streaming data endpoint. The Windows audio stack requires
  		 *  at least 192 bytes for correct output, thus the smaller 128 byte maximum endpoint size on some of the smaller
  		 *  USB AVR models will result in unavoidable distorted output.
  		 */
  		#define AUDIO_STREAM_EPSIZE          ENDPOINT_MAX_SIZE(AUDIO_STREAM_EPNUM)
  		
  		/** Sample frequency of the data being transmitted through the streaming endpoint. */
  		#define AUDIO_SAMPLE_FREQUENCY       48000
  		
  	/* Type Defines: */
  		/** Type define for an Audio class specific interface descriptor. This follows a regular interface descriptor to
  		 *  supply extra information about the audio device's layout to the host. See the USB Audio specification for more
  		 *  details.
  		 */
  		typedef struct
  		{
  			USB_Descriptor_Header_t   Header; /**< Regular descriptor header containing the descriptor's type and length */
  			uint8_t                   Subtype; /**< Sub type value used to distinguish between audio class specific descriptors */
  
  			uint16_t                  ACSpecification; /**< Binary coded decimal value, indicating the supported Audio Class specification version */
  			uint16_t                  TotalLength; /**< Total length of the Audio class specific descriptors, including this descriptor */
  			
  			uint8_t                   InCollection; /**< Total number of audio class interfaces within this device */
  			uint8_t                   InterfaceNumbers[1]; /**< Interface numbers of each audio interface */
  		} USB_Audio_Interface_AC_t;
  		
  		/** Type define for an Audio class specific Feature Unit descriptor. This indicates to the host what features
  		 *  are present in the device's audio stream for basic control, such as per-channel volume. See the USB Audio
  		 *  specification for more details.
  		 */
  		typedef struct
  		{
  			USB_Descriptor_Header_t   Header; /**< Regular descriptor header containing the descriptor's type and length */
  			uint8_t                   Subtype; /**< Sub type value used to distinguish between audio class specific descriptors */
  			
  			uint8_t                   UnitID; /**< ID value of this feature unit - must be a unique value within the device */
  			uint8_t                   SourceID; /**< Source ID value of the audio source input into this feature unit */
  			
  			uint8_t                   ControlSize; /**< Size of each element in the ChanelControlls array */
  			uint8_t                   ChannelControls[3]; /**< Feature masks for the control channel, and each separate audio channel */
  			
  			uint8_t                   FeatureUnitStrIndex; /**< Index of a string descriptor describing this descriptor within the device */
  		} USB_Audio_FeatureUnit_t;
  
  		/** Type define for an Audio class specific input terminal descriptor. This indicates to the host that the device
  		 *  contains an input audio source, either from a physical terminal on the device, or a logical terminal (for example,
  		 *  a USB endpoint). See the USB Audio specification for more details.
  		 */
  		typedef struct
  		{
  			USB_Descriptor_Header_t   Header; /**< Regular descriptor header containing the descriptor's type and length */
  			uint8_t                   Subtype; /**< Sub type value used to distinguish between audio class specific descriptors */
  		
  			uint8_t                   TerminalID; /**< ID value of this terminal unit - must be a unique value within the device */
  			uint16_t                  TerminalType; /**< Type of terminal, a TERMINAL_* mask */
  			uint8_t                   AssociatedOutputTerminal; /**< ID of associated output terminal, for physically grouped terminals
  			                                                     *   such as the speaker and microphone of a phone handset
  			                                                     */
  			uint8_t                   TotalChannels; /**< Total number of separate audio channels within this interface (right, left, etc.) */
  			uint16_t                  ChannelConfig; /**< CHANNEL_* masks indicating what channel layout is supported by this terminal */
  			
  			uint8_t                   ChannelStrIndex; /**< Index of a string descriptor describing this channel within the device */
  			uint8_t                   TerminalStrIndex; /**< Index of a string descriptor describing this descriptor within the device */
  		} USB_Audio_InputTerminal_t;
  
  		/** Type define for an Audio class specific output terminal descriptor. This indicates to the host that the device
  		 *  contains an output audio sink, either to a physical terminal on the device, or a logical terminal (for example,
  		 *  a USB endpoint). See the USB Audio specification for more details.
  		 */
  		typedef struct
  		{
  			USB_Descriptor_Header_t   Header; /**< Regular descriptor header containing the descriptor's type and length */
  			uint8_t                   Subtype; /**< Sub type value used to distinguish between audio class specific descriptors */
  		
  			uint8_t                   TerminalID; /**< ID value of this terminal unit - must be a unique value within the device */
  			uint16_t                  TerminalType; /**< Type of terminal, a TERMINAL_* mask */
  			uint8_t                   AssociatedInputTerminal; /**< ID of associated input terminal, for physically grouped terminals
  			                                                    *   such as the speaker and microphone of a phone handset
  			                                                    */
  			uint8_t                   SourceID; /**< ID value of the unit this terminal's audio is sourced from */
  			
  			uint8_t                   TerminalStrIndex; /**< Index of a string descriptor describing this descriptor within the device */
  		} USB_Audio_OutputTerminal_t;
  		
  		/** Type define for an Audio class specific streaming interface descriptor. This indicates to the host
  		 *  how audio streams within the device are formatted. See the USB Audio specification for more details.
  		 */
  		typedef struct
  		{
  			USB_Descriptor_Header_t   Header; /**< Regular descriptor header containing the descriptor's type and length */
  			uint8_t                   Subtype; /**< Sub type value used to distinguish between audio class specific descriptors */
  			
  			uint8_t                   TerminalLink; /**< ID value of the output terminal this descriptor is describing */
  			
  			uint8_t                   FrameDelay; /**< Delay in frames resulting from the complete sample processing from input to output */
  			uint16_t                  AudioFormat; /**< Format of the audio stream, see Audio Device Formats specification */
  		} USB_Audio_Interface_AS_t;
  		
  		/** Type define for a 24bit audio sample frequency structure. GCC does not contain a built in 24bit datatype,
  		 *  this this structure is used to build up the value instead. Fill this structure with the SAMPLE_FREQ() macro.
  		 */
  		typedef struct
  		{
  			uint16_t                  LowWord; /**< Low 16 bits of the 24-bit value */
  			uint8_t                   HighByte; /**< Upper 8 bits of the 24-bit value */
  		} Audio_SampleFreq_t;
  
  		/** Type define for an Audio class specific audio format descriptor. This is used to give the host full details
  		 *  about the number of channels, the sample resolution, acceptable sample frequencies and encoding method used
  		 *  in the device's audio streams. See the USB Audio specification for more details.
  		 */
  		typedef struct
  		{
  			USB_Descriptor_Header_t   Header; /**< Regular descriptor header containing the descriptor's type and length */
  			uint8_t                   Subtype; /**< Sub type value used to distinguish between audio class specific descriptors */
  
  			uint8_t                   FormatType; /**< Format of the audio stream, see Audio Device Formats specification */
  			uint8_t                   Channels; /**< Total number of discrete channels in the stream */
  			
  			uint8_t                   SubFrameSize; /**< Size in bytes of each channel's sample data in the stream */
  			uint8_t                   BitResolution; /**< Bits of resolution of each channel's samples in the stream */
  
  			uint8_t                   SampleFrequencyType; /**< Total number of sample frequencies supported by the device */			
  			Audio_SampleFreq_t        SampleFrequencies[1]; /**< Sample frequencies supported by the device */
  		} USB_Audio_Format_t;
  		
  		/** Type define for an Audio class specific endpoint descriptor. This contains a regular endpoint 
  		 *  descriptor with a few Audio-class specific extensions. See the USB Audio specification for more details.
  		 */
  		typedef struct
  		{
  			USB_Descriptor_Endpoint_t Endpoint; /**< Standard endpoint descriptor describing the audio endpoint */
  
  			uint8_t                   Refresh; /**< Always set to zero */
  			uint8_t                   SyncEndpointNumber; /**< Endpoint address to send synchronization information to, if needed (zero otherwise) */
  		} USB_Audio_StreamEndpoint_Std_t;
  					
  		/** Type define for an Audio class specific extended endpoint descriptor. This contains extra information
  		 *  on the usage of endpoints used to stream audio in and out of the USB Audio device, and follows an Audio
  		 *  class specific extended endpoint descriptor. See the USB Audio specification for more details.
  		 */
  		typedef struct
  		{
  			USB_Descriptor_Header_t   Header; /**< Regular descriptor header containing the descriptor's type and length */
  			uint8_t                   Subtype; /**< Sub type value used to distinguish between audio class specific descriptors */
  			
  			uint8_t                   Attributes; /**< Audio class specific endpoint attributes, such as ACCEPTS_SMALL_PACKETS */
  
  			uint8_t                   LockDelayUnits; /**< Units used for the LockDelay field, see Audio class specification */
  			uint16_t                  LockDelay; /**< Time required to internally lock endpoint's internal clock recovery circuitry */
  		} USB_Audio_StreamEndpoint_Spc_t;
  		
  		/** Type define for the device configuration descriptor structure. This must be defined in the
  		 *  application code, as the configuration descriptor contains several sub-descriptors which
  		 *  vary between devices, and which describe the device's usage to the host.
  		 */
  		typedef struct
  		{
  			USB_Descriptor_Configuration_Header_t Config;
  			USB_Descriptor_Interface_t            AudioControlInterface;
  			USB_Audio_Interface_AC_t              AudioControlInterface_SPC;
  			USB_Audio_InputTerminal_t             InputTerminal;
  			USB_Audio_OutputTerminal_t            OutputTerminal;
  			USB_Descriptor_Interface_t            AudioStreamInterface_Alt0;
  			USB_Descriptor_Interface_t            AudioStreamInterface_Alt1;
  			USB_Audio_Interface_AS_t              AudioStreamInterface_SPC;
  			USB_Audio_Format_t                    AudioFormat;
  			USB_Audio_StreamEndpoint_Std_t        AudioEndpoint;
  			USB_Audio_StreamEndpoint_Spc_t        AudioEndpoint_SPC;
  		} USB_Descriptor_Configuration_t;
  		
  	/* Function Prototypes: */
  		uint16_t CALLBACK_USB_GetDescriptor(const uint16_t wValue, const uint8_t wIndex, void** const DescriptorAddress)
  		                                    ATTR_WARN_UNUSED_RESULT ATTR_NON_NULL_PTR_ARG(3);
  
  #endif
  