rt-thread/components/drivers/usb/usbdevice/class/audio.h

/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
/*
 * <linux/usb/audio.h> -- USB Audio definitions.
 *
 * Copyright (C) 2006 Thumtronics Pty Ltd.
 * Developed for Thumtronics by Grey Innovation
 * Ben Williamson <ben.williamson@greyinnovation.com>
 *
 * This software is distributed under the terms of the GNU General Public
 * License ("GPL") version 2, as published by the Free Software Foundation.
 *
 * This file holds USB constants and structures defined
 * by the USB Device Class Definition for Audio Devices.
 * Comments below reference relevant sections of that document:
 *
 * http://www.usb.org/developers/devclass_docs/audio10.pdf
 *
 * Types and defines in this file are either specific to version 1.0 of
 * this standard or common for newer versions.
 */

#ifndef _UAPI__LINUX_USB_AUDIO_H
#define _UAPI__LINUX_USB_AUDIO_H

//#include <linux/types.h>
#include <rtthread.h>

typedef int8_t   __s8;
typedef uint8_t  __u8;
typedef int16_t  __s16;
typedef uint16_t __u16;
typedef int32_t  __s32;
typedef uint32_t __u32;
typedef int64_t  __s64;
typedef uint64_t __u64;

#define UAC_USE_FEATURE_UNIT  0  /* Feature unit does not support */

/*
 * Below are truly Linux-specific types that should never collide with
 * any application/library that wants linux/types.h.
 */

#ifdef __CHECKER__
#define __bitwise__ __attribute__((bitwise))
#else
#define __bitwise__
#endif
#ifdef __CHECK_ENDIAN__
#define __bitwise __bitwise__
#else
#define __bitwise
#endif

typedef __u16 __bitwise __le16;
typedef __u16 __bitwise __be16;
typedef __u32 __bitwise __le32;
typedef __u32 __bitwise __be32;
typedef __u64 __bitwise __le64;
typedef __u64 __bitwise __be64;

typedef __u16 __bitwise __sum16;
typedef __u32 __bitwise __wsum;

/* bInterfaceProtocol values to denote the version of the standard used */
#define UAC_VERSION_1           0x00
#define UAC_VERSION_2           0x20
#define UAC_VERSION_3           0x30

/* A.2 Audio Interface Subclass Codes */
#define USB_SUBCLASS_AUDIOCONTROL   0x01
#define USB_SUBCLASS_AUDIOSTREAMING 0x02
#define USB_SUBCLASS_MIDISTREAMING  0x03

/* A.5 Audio Class-Specific AC Interface Descriptor Subtypes */
#define UAC_HEADER          0x01
#define UAC_INPUT_TERMINAL      0x02
#define UAC_OUTPUT_TERMINAL     0x03
#define UAC_MIXER_UNIT          0x04
#define UAC_SELECTOR_UNIT       0x05
#define UAC_FEATURE_UNIT        0x06
#define UAC1_PROCESSING_UNIT        0x07
#define UAC1_EXTENSION_UNIT     0x08

/* A.6 Audio Class-Specific AS Interface Descriptor Subtypes */
#define UAC_AS_GENERAL          0x01
#define UAC_FORMAT_TYPE         0x02
#define UAC_FORMAT_SPECIFIC     0x03

/* A.7 Processing Unit Process Types */
#define UAC_PROCESS_UNDEFINED       0x00
#define UAC_PROCESS_UP_DOWNMIX      0x01
#define UAC_PROCESS_DOLBY_PROLOGIC  0x02
#define UAC_PROCESS_STEREO_EXTENDER 0x03
#define UAC_PROCESS_REVERB      0x04
#define UAC_PROCESS_CHORUS      0x05
#define UAC_PROCESS_DYN_RANGE_COMP  0x06

/* A.8 Audio Class-Specific Endpoint Descriptor Subtypes */
#define UAC_EP_GENERAL          0x01

/* A.9 Audio Class-Specific Request Codes */
#define UAC_SET_            0x00
#define UAC_GET_            0x80

#define UAC__CUR            0x1
#define UAC__MIN            0x2
#define UAC__MAX            0x3
#define UAC__RES            0x4
#define UAC__MEM            0x5

#define UAC_SET_CUR         (UAC_SET_ | UAC__CUR)
#define UAC_GET_CUR         (UAC_GET_ | UAC__CUR)
#define UAC_SET_MIN         (UAC_SET_ | UAC__MIN)
#define UAC_GET_MIN         (UAC_GET_ | UAC__MIN)
#define UAC_SET_MAX         (UAC_SET_ | UAC__MAX)
#define UAC_GET_MAX         (UAC_GET_ | UAC__MAX)
#define UAC_SET_RES         (UAC_SET_ | UAC__RES)
#define UAC_GET_RES         (UAC_GET_ | UAC__RES)
#define UAC_SET_MEM         (UAC_SET_ | UAC__MEM)
#define UAC_GET_MEM         (UAC_GET_ | UAC__MEM)

#define UAC_GET_STAT            0xff

/* A.10 Control Selector Codes */

/* A.10.1 Terminal Control Selectors */
#define UAC_TERM_COPY_PROTECT       0x01

/* A.10.2 Feature Unit Control Selectors */
#define UAC_FU_MUTE         0x01
#define UAC_FU_VOLUME           0x02
#define UAC_FU_BASS         0x03
#define UAC_FU_MID          0x04
#define UAC_FU_TREBLE           0x05
#define UAC_FU_GRAPHIC_EQUALIZER    0x06
#define UAC_FU_AUTOMATIC_GAIN       0x07
#define UAC_FU_DELAY            0x08
#define UAC_FU_BASS_BOOST       0x09
#define UAC_FU_LOUDNESS         0x0a

#define UAC_CONTROL_BIT(CS) (1 << ((CS) - 1))

/* A.10.3.1 Up/Down-mix Processing Unit Controls Selectors */
#define UAC_UD_ENABLE           0x01
#define UAC_UD_MODE_SELECT      0x02

/* A.10.3.2 Dolby Prologic (tm) Processing Unit Controls Selectors */
#define UAC_DP_ENABLE           0x01
#define UAC_DP_MODE_SELECT      0x02

/* A.10.3.3 3D Stereo Extender Processing Unit Control Selectors */
#define UAC_3D_ENABLE           0x01
#define UAC_3D_SPACE            0x02

/* A.10.3.4 Reverberation Processing Unit Control Selectors */
#define UAC_REVERB_ENABLE       0x01
#define UAC_REVERB_LEVEL        0x02
#define UAC_REVERB_TIME         0x03
#define UAC_REVERB_FEEDBACK     0x04

/* A.10.3.5 Chorus Processing Unit Control Selectors */
#define UAC_CHORUS_ENABLE       0x01
#define UAC_CHORUS_LEVEL        0x02
#define UAC_CHORUS_RATE         0x03
#define UAC_CHORUS_DEPTH        0x04

/* A.10.3.6 Dynamic Range Compressor Unit Control Selectors */
#define UAC_DCR_ENABLE          0x01
#define UAC_DCR_RATE            0x02
#define UAC_DCR_MAXAMPL         0x03
#define UAC_DCR_THRESHOLD       0x04
#define UAC_DCR_ATTACK_TIME     0x05
#define UAC_DCR_RELEASE_TIME        0x06

/* A.10.4 Extension Unit Control Selectors */
#define UAC_XU_ENABLE           0x01

/* MIDI - A.1 MS Class-Specific Interface Descriptor Subtypes */
#define UAC_MS_HEADER           0x01
#define UAC_MIDI_IN_JACK        0x02
#define UAC_MIDI_OUT_JACK       0x03

/* MIDI - A.1 MS Class-Specific Endpoint Descriptor Subtypes */
#define UAC_MS_GENERAL          0x01

/* Terminals - 2.1 USB Terminal Types */
#define UAC_TERMINAL_UNDEFINED      0x100
#define UAC_TERMINAL_STREAMING      0x101
#define UAC_TERMINAL_VENDOR_SPEC    0x1FF

/* Terminal Control Selectors */
/* 4.3.2  Class-Specific AC Interface Descriptor */
struct uac1_ac_header_descriptor {
    __u8  bLength;          /* 8 + n */
    __u8  bDescriptorType;      /* USB_DT_CS_INTERFACE */
    __u8  bDescriptorSubtype;   /* UAC_MS_HEADER */
    __le16 bcdADC;          /* 0x0100 */
    __le16 wTotalLength;        /* includes Unit and Terminal desc. */
    __u8  bInCollection;        /* n */
    __u8  baInterfaceNr[];      /* [n] */
} __attribute__ ((packed));

#define UAC_DT_AC_HEADER_SIZE(n)    (8 + (n))

/* As above, but more useful for defining your own descriptors: */
#define DECLARE_UAC_AC_HEADER_DESCRIPTOR(n)         \
struct uac1_ac_header_descriptor_##n {          \
    __u8  bLength;                      \
    __u8  bDescriptorType;                  \
    __u8  bDescriptorSubtype;               \
    __le16 bcdADC;                      \
    __le16 wTotalLength;                    \
    __u8  bInCollection;                    \
    __u8  baInterfaceNr[n];                 \
} __attribute__ ((packed))

/* 4.3.2.1 Input Terminal Descriptor */
struct uac_input_terminal_descriptor {
    __u8  bLength;          /* in bytes: 12 */
    __u8  bDescriptorType;      /* CS_INTERFACE descriptor type */
    __u8  bDescriptorSubtype;   /* INPUT_TERMINAL descriptor subtype */
    __u8  bTerminalID;      /* Constant uniquely terminal ID */
    __le16 wTerminalType;       /* USB Audio Terminal Types */
    __u8  bAssocTerminal;       /* ID of the Output Terminal associated */
    __u8  bNrChannels;      /* Number of logical output channels */
    __le16 wChannelConfig;
    __u8  iChannelNames;
    __u8  iTerminal;
} __attribute__ ((packed));

#define UAC_DT_INPUT_TERMINAL_SIZE          12

/* Terminals - 2.2 Input Terminal Types */
#define UAC_INPUT_TERMINAL_UNDEFINED            0x200
#define UAC_INPUT_TERMINAL_MICROPHONE           0x201
#define UAC_INPUT_TERMINAL_DESKTOP_MICROPHONE       0x202
#define UAC_INPUT_TERMINAL_PERSONAL_MICROPHONE      0x203
#define UAC_INPUT_TERMINAL_OMNI_DIR_MICROPHONE      0x204
#define UAC_INPUT_TERMINAL_MICROPHONE_ARRAY     0x205
#define UAC_INPUT_TERMINAL_PROC_MICROPHONE_ARRAY    0x206

/* Terminals - control selectors */

#define UAC_TERMINAL_CS_COPY_PROTECT_CONTROL        0x01

/* 4.3.2.2 Output Terminal Descriptor */
struct uac1_output_terminal_descriptor {
    __u8  bLength;          /* in bytes: 9 */
    __u8  bDescriptorType;      /* CS_INTERFACE descriptor type */
    __u8  bDescriptorSubtype;   /* OUTPUT_TERMINAL descriptor subtype */
    __u8  bTerminalID;      /* Constant uniquely terminal ID */
    __le16 wTerminalType;       /* USB Audio Terminal Types */
    __u8  bAssocTerminal;       /* ID of the Input Terminal associated */
    __u8  bSourceID;        /* ID of the connected Unit or Terminal*/
    __u8  iTerminal;
} __attribute__ ((packed));

#define UAC_DT_OUTPUT_TERMINAL_SIZE         9

/* Terminals - 2.3 Output Terminal Types */
#define UAC_OUTPUT_TERMINAL_UNDEFINED           0x300
#define UAC_OUTPUT_TERMINAL_SPEAKER         0x301
#define UAC_OUTPUT_TERMINAL_HEADPHONES          0x302
#define UAC_OUTPUT_TERMINAL_HEAD_MOUNTED_DISPLAY_AUDIO  0x303
#define UAC_OUTPUT_TERMINAL_DESKTOP_SPEAKER     0x304
#define UAC_OUTPUT_TERMINAL_ROOM_SPEAKER        0x305
#define UAC_OUTPUT_TERMINAL_COMMUNICATION_SPEAKER   0x306
#define UAC_OUTPUT_TERMINAL_LOW_FREQ_EFFECTS_SPEAKER    0x307

/* Terminals - 2.4 Bi-directional Terminal Types */
#define UAC_BIDIR_TERMINAL_UNDEFINED            0x400
#define UAC_BIDIR_TERMINAL_HANDSET          0x401
#define UAC_BIDIR_TERMINAL_HEADSET          0x402
#define UAC_BIDIR_TERMINAL_SPEAKER_PHONE        0x403
#define UAC_BIDIR_TERMINAL_ECHO_SUPPRESSING     0x404
#define UAC_BIDIR_TERMINAL_ECHO_CANCELING       0x405

/* Set bControlSize = 2 as default setting */
#define UAC_DT_FEATURE_UNIT_SIZE(ch)        (7 + ((ch) + 1) * 2)

/* As above, but more useful for defining your own descriptors: */
#define DECLARE_UAC_FEATURE_UNIT_DESCRIPTOR(ch)         \
struct uac_feature_unit_descriptor_##ch {           \
    __u8  bLength;                      \
    __u8  bDescriptorType;                  \
    __u8  bDescriptorSubtype;               \
    __u8  bUnitID;                      \
    __u8  bSourceID;                    \
    __u8  bControlSize;                 \
    __le16 bmaControls[ch + 1];             \
    __u8  iFeature;                     \
} __attribute__ ((packed))

/* 4.3.2.3 Mixer Unit Descriptor */
struct uac_mixer_unit_descriptor {
    __u8 bLength;
    __u8 bDescriptorType;
    __u8 bDescriptorSubtype;
    __u8 bUnitID;
    __u8 bNrInPins;
    __u8 baSourceID[];
} __attribute__ ((packed));

static inline __u8 uac_mixer_unit_bNrChannels(struct uac_mixer_unit_descriptor *desc)
{
    return desc->baSourceID[desc->bNrInPins];
}

static inline __u32 uac_mixer_unit_wChannelConfig(struct uac_mixer_unit_descriptor *desc,
                          int protocol)
{
    if (protocol == UAC_VERSION_1)
        return (desc->baSourceID[desc->bNrInPins + 2] << 8) |
            desc->baSourceID[desc->bNrInPins + 1];
    else
        return  (desc->baSourceID[desc->bNrInPins + 4] << 24) |
            (desc->baSourceID[desc->bNrInPins + 3] << 16) |
            (desc->baSourceID[desc->bNrInPins + 2] << 8)  |
            (desc->baSourceID[desc->bNrInPins + 1]);
}

static inline __u8 uac_mixer_unit_iChannelNames(struct uac_mixer_unit_descriptor *desc,
                        int protocol)
{
    return (protocol == UAC_VERSION_1) ?
        desc->baSourceID[desc->bNrInPins + 3] :
        desc->baSourceID[desc->bNrInPins + 5];
}

static inline __u8 *uac_mixer_unit_bmControls(struct uac_mixer_unit_descriptor *desc,
                          int protocol)
{
    switch (protocol) {
    case UAC_VERSION_1:
        return &desc->baSourceID[desc->bNrInPins + 4];
    case UAC_VERSION_2:
        return &desc->baSourceID[desc->bNrInPins + 6];
    case UAC_VERSION_3:
        return &desc->baSourceID[desc->bNrInPins + 2];
    default:
        return NULL;
    }
}

static inline __u16 uac3_mixer_unit_wClusterDescrID(struct uac_mixer_unit_descriptor *desc)
{
    return (desc->baSourceID[desc->bNrInPins + 1] << 8) |
        desc->baSourceID[desc->bNrInPins];
}

static inline __u8 uac_mixer_unit_iMixer(struct uac_mixer_unit_descriptor *desc)
{
    __u8 *raw = (__u8 *) desc;
    return raw[desc->bLength - 1];
}

/* 4.3.2.4 Selector Unit Descriptor */
struct uac_selector_unit_descriptor {
    __u8 bLength;
    __u8 bDescriptorType;
    __u8 bDescriptorSubtype;
    __u8 bUintID;
    __u8 bNrInPins;
    __u8 baSourceID[];
} __attribute__ ((packed));

static inline __u8 uac_selector_unit_iSelector(struct uac_selector_unit_descriptor *desc)
{
    __u8 *raw = (__u8 *) desc;
    return raw[desc->bLength - 1];
}
#if UAC_USE_FEATURE_UNIT
/* 4.3.2.5 Feature Unit Descriptor */
struct uac_feature_unit_descriptor {
    __u8 bLength;
    __u8 bDescriptorType;
    __u8 bDescriptorSubtype;
    __u8 bUnitID;
    __u8 bSourceID;
    __u8 bControlSize;
    __u8 bmaControls[0]; /* variable length */
} __attribute__((packed));

static inline __u8 uac_feature_unit_iFeature(struct uac_feature_unit_descriptor *desc)
{
    __u8 *raw = (__u8 *) desc;
    return raw[desc->bLength - 1];
}
#endif
/* 4.3.2.6 Processing Unit Descriptors */
struct uac_processing_unit_descriptor {
    __u8 bLength;
    __u8 bDescriptorType;
    __u8 bDescriptorSubtype;
    __u8 bUnitID;
    __le16 wProcessType;
    __u8 bNrInPins;
    __u8 baSourceID[];
} __attribute__ ((packed));

static inline __u8 uac_processing_unit_bNrChannels(struct uac_processing_unit_descriptor *desc)
{
    return desc->baSourceID[desc->bNrInPins];
}

static inline __u32 uac_processing_unit_wChannelConfig(struct uac_processing_unit_descriptor *desc,
                               int protocol)
{
    if (protocol == UAC_VERSION_1)
        return (desc->baSourceID[desc->bNrInPins + 2] << 8) |
            desc->baSourceID[desc->bNrInPins + 1];
    else
        return  (desc->baSourceID[desc->bNrInPins + 4] << 24) |
            (desc->baSourceID[desc->bNrInPins + 3] << 16) |
            (desc->baSourceID[desc->bNrInPins + 2] << 8)  |
            (desc->baSourceID[desc->bNrInPins + 1]);
}

static inline __u8 uac_processing_unit_iChannelNames(struct uac_processing_unit_descriptor *desc,
                             int protocol)
{
    return (protocol == UAC_VERSION_1) ?
        desc->baSourceID[desc->bNrInPins + 3] :
        desc->baSourceID[desc->bNrInPins + 5];
}

static inline __u8 uac_processing_unit_bControlSize(struct uac_processing_unit_descriptor *desc,
                            int protocol)
{
    switch (protocol) {
    case UAC_VERSION_1:
        return desc->baSourceID[desc->bNrInPins + 4];
    case UAC_VERSION_2:
        return 2; /* in UAC2, this value is constant */
    case UAC_VERSION_3:
        return 4; /* in UAC3, this value is constant */
    default:
        return 1;
    }
}

static inline __u8 *uac_processing_unit_bmControls(struct uac_processing_unit_descriptor *desc,
                           int protocol)
{
    switch (protocol) {
    case UAC_VERSION_1:
        return &desc->baSourceID[desc->bNrInPins + 5];
    case UAC_VERSION_2:
        return &desc->baSourceID[desc->bNrInPins + 6];
    case UAC_VERSION_3:
        return &desc->baSourceID[desc->bNrInPins + 2];
    default:
        return NULL;
    }
}

static inline __u8 uac_processing_unit_iProcessing(struct uac_processing_unit_descriptor *desc,
                           int protocol)
{
    __u8 control_size = uac_processing_unit_bControlSize(desc, protocol);

    switch (protocol) {
    case UAC_VERSION_1:
    case UAC_VERSION_2:
    default:
        return *(uac_processing_unit_bmControls(desc, protocol)
             + control_size);
    case UAC_VERSION_3:
        return 0; /* UAC3 does not have this field */
    }
}

static inline __u8 *uac_processing_unit_specific(struct uac_processing_unit_descriptor *desc,
                         int protocol)
{
    __u8 control_size = uac_processing_unit_bControlSize(desc, protocol);

    switch (protocol) {
    case UAC_VERSION_1:
    case UAC_VERSION_2:
    default:
        return uac_processing_unit_bmControls(desc, protocol)
            + control_size + 1;
    case UAC_VERSION_3:
        return uac_processing_unit_bmControls(desc, protocol)
            + control_size;
    }
}

/*
 * Extension Unit (XU) has almost compatible layout with Processing Unit, but
 * on UAC2, it has a different bmControls size (bControlSize); it's 1 byte for
 * XU while 2 bytes for PU.  The last iExtension field is a one-byte index as
 * well as iProcessing field of PU.
 */
static inline __u8 uac_extension_unit_bControlSize(struct uac_processing_unit_descriptor *desc,
                           int protocol)
{
    switch (protocol) {
    case UAC_VERSION_1:
        return desc->baSourceID[desc->bNrInPins + 4];
    case UAC_VERSION_2:
        return 1; /* in UAC2, this value is constant */
    case UAC_VERSION_3:
        return 4; /* in UAC3, this value is constant */
    default:
        return 1;
    }
}

static inline __u8 uac_extension_unit_iExtension(struct uac_processing_unit_descriptor *desc,
                         int protocol)
{
    __u8 control_size = uac_extension_unit_bControlSize(desc, protocol);

    switch (protocol) {
    case UAC_VERSION_1:
    case UAC_VERSION_2:
    default:
        return *(uac_processing_unit_bmControls(desc, protocol)
             + control_size);
    case UAC_VERSION_3:
        return 0; /* UAC3 does not have this field */
    }
}

/* 4.5.2 Class-Specific AS Interface Descriptor */
struct uac1_as_header_descriptor {
    __u8  bLength;          /* in bytes: 7 */
    __u8  bDescriptorType;      /* USB_DT_CS_INTERFACE */
    __u8  bDescriptorSubtype;   /* AS_GENERAL */
    __u8  bTerminalLink;        /* Terminal ID of connected Terminal */
    __u8  bDelay;           /* Delay introduced by the data path */
    __le16 wFormatTag;      /* The Audio Data Format */
} __attribute__ ((packed));

#define UAC_DT_AS_HEADER_SIZE       7

/* Formats - A.1.1 Audio Data Format Type I Codes */
#define UAC_FORMAT_TYPE_I_UNDEFINED 0x0
#define UAC_FORMAT_TYPE_I_PCM       0x1
#define UAC_FORMAT_TYPE_I_PCM8      0x2
#define UAC_FORMAT_TYPE_I_IEEE_FLOAT    0x3
#define UAC_FORMAT_TYPE_I_ALAW      0x4
#define UAC_FORMAT_TYPE_I_MULAW     0x5

struct uac_format_type_i_continuous_descriptor {
    __u8  bLength;          /* in bytes: 8 + (ns * 3) */
    __u8  bDescriptorType;      /* USB_DT_CS_INTERFACE */
    __u8  bDescriptorSubtype;   /* FORMAT_TYPE */
    __u8  bFormatType;      /* FORMAT_TYPE_1 */
    __u8  bNrChannels;      /* physical channels in the stream */
    __u8  bSubframeSize;        /* */
    __u8  bBitResolution;
    __u8  bSamFreqType;
    __u8  tLowerSamFreq[3];
    __u8  tUpperSamFreq[3];
} __attribute__ ((packed));

#define UAC_FORMAT_TYPE_I_CONTINUOUS_DESC_SIZE  14

struct uac_format_type_i_discrete_descriptor {
    __u8  bLength;          /* in bytes: 8 + (ns * 3) */
    __u8  bDescriptorType;      /* USB_DT_CS_INTERFACE */
    __u8  bDescriptorSubtype;   /* FORMAT_TYPE */
    __u8  bFormatType;      /* FORMAT_TYPE_1 */
    __u8  bNrChannels;      /* physical channels in the stream */
    __u8  bSubframeSize;        /* */
    __u8  bBitResolution;
    __u8  bSamFreqType;
    __u8  tSamFreq[][3];
} __attribute__ ((packed));

#define DECLARE_UAC_FORMAT_TYPE_I_DISCRETE_DESC(n)      \
struct uac_format_type_i_discrete_descriptor_##n {      \
    __u8  bLength;                      \
    __u8  bDescriptorType;                  \
    __u8  bDescriptorSubtype;               \
    __u8  bFormatType;                  \
    __u8  bNrChannels;                  \
    __u8  bSubframeSize;                    \
    __u8  bBitResolution;                   \
    __u8  bSamFreqType;                 \
    __u8  tSamFreq[n][3];                   \
} __attribute__ ((packed))

#define UAC_FORMAT_TYPE_I_DISCRETE_DESC_SIZE(n) (8 + (n * 3))

struct uac_format_type_i_ext_descriptor {
    __u8 bLength;
    __u8 bDescriptorType;
    __u8 bDescriptorSubtype;
    __u8 bFormatType;
    __u8 bSubslotSize;
    __u8 bBitResolution;
    __u8 bHeaderLength;
    __u8 bControlSize;
    __u8 bSideBandProtocol;
} __attribute__((packed));

/* Formats - Audio Data Format Type I Codes */

#define UAC_FORMAT_TYPE_II_MPEG 0x1001
#define UAC_FORMAT_TYPE_II_AC3  0x1002

struct uac_format_type_ii_discrete_descriptor {
    __u8 bLength;
    __u8 bDescriptorType;
    __u8 bDescriptorSubtype;
    __u8 bFormatType;
    __le16 wMaxBitRate;
    __le16 wSamplesPerFrame;
    __u8 bSamFreqType;
    __u8 tSamFreq[][3];
} __attribute__((packed));

struct uac_format_type_ii_ext_descriptor {
    __u8 bLength;
    __u8 bDescriptorType;
    __u8 bDescriptorSubtype;
    __u8 bFormatType;
    __le16 wMaxBitRate;
    __le16 wSamplesPerFrame;
    __u8 bHeaderLength;
    __u8 bSideBandProtocol;
} __attribute__((packed));

/* type III */
#define UAC_FORMAT_TYPE_III_IEC1937_AC3 0x2001
#define UAC_FORMAT_TYPE_III_IEC1937_MPEG1_LAYER1    0x2002
#define UAC_FORMAT_TYPE_III_IEC1937_MPEG2_NOEXT 0x2003
#define UAC_FORMAT_TYPE_III_IEC1937_MPEG2_EXT   0x2004
#define UAC_FORMAT_TYPE_III_IEC1937_MPEG2_LAYER1_LS 0x2005
#define UAC_FORMAT_TYPE_III_IEC1937_MPEG2_LAYER23_LS    0x2006

/* Formats - A.2 Format Type Codes */
#define UAC_FORMAT_TYPE_UNDEFINED   0x0
#define UAC_FORMAT_TYPE_I       0x1
#define UAC_FORMAT_TYPE_II      0x2
#define UAC_FORMAT_TYPE_III     0x3
#define UAC_EXT_FORMAT_TYPE_I       0x81
#define UAC_EXT_FORMAT_TYPE_II      0x82
#define UAC_EXT_FORMAT_TYPE_III     0x83

struct uac_iso_endpoint_descriptor {
    __u8  bLength;          /* in bytes: 7 */
    __u8  bDescriptorType;      /* USB_DT_CS_ENDPOINT */
    __u8  bDescriptorSubtype;   /* EP_GENERAL */
    __u8  bmAttributes;
    __u8  bLockDelayUnits;
    __le16 wLockDelay;
} __attribute__((packed));
#define UAC_ISO_ENDPOINT_DESC_SIZE  7

#define UAC_EP_CS_ATTR_SAMPLE_RATE  0x01
#define UAC_EP_CS_ATTR_PITCH_CONTROL    0x02
#define UAC_EP_CS_ATTR_FILL_MAX     0x80

/* status word format (3.7.1.1) */

#define UAC1_STATUS_TYPE_ORIG_MASK      0x0f
#define UAC1_STATUS_TYPE_ORIG_AUDIO_CONTROL_IF  0x0
#define UAC1_STATUS_TYPE_ORIG_AUDIO_STREAM_IF   0x1
#define UAC1_STATUS_TYPE_ORIG_AUDIO_STREAM_EP   0x2

#define UAC1_STATUS_TYPE_IRQ_PENDING        (1 << 7)
#define UAC1_STATUS_TYPE_MEM_CHANGED        (1 << 6)

struct uac1_status_word {
    __u8 bStatusType;
    __u8 bOriginator;
} __attribute__((packed));


#endif /* _UAPI__LINUX_USB_AUDIO_H */