UAC麦克风设备描述符

所有的USB设备第一个要设计的描述符基本都是设备描述符。这里的UAC音频设备描述符数据配置如下：

结构体定义如下：

/* USB_DT_DEVICE: Device descriptor */
struct usb_device_descriptor {
    __u8 bLength;
    __u8 bDescriptorType;
    __le16 bcdUSB;
    __u8 bDeviceClass;
    __u8 bDeviceSubClass;
    __u8 bDeviceProtocol;
    __u8 bMaxPacketSize0;
    __le16 idVendor;
    __le16 idProduct;
    __le16 bcdDevice;
    __u8 iManufacturer;
    __u8 iProduct;
    __u8 iSerialNumber;
    __u8 bNumConfigurations;
}
__attribute__((packed));

关于设备描述符的详尽分析可详见：http://www.usbzh.com/article/detail-104.html

通过Free Device Monitoring Studio 抓取模拟设备信息：

• This device is part of a composite device.
• Connection Information Port: 2
• Speed: High Speed (USB 2.0)
• Device address: 7
• Open pipes: 1
• Connection status: Device connected Device Descriptor
• USB version: 2.0
• Device class: 0x0 - (Defined at Interface level)
• Device subclass: 0x0 - Unknown
• Device protocol: 0x0 - Unknown Control pipe max size: 64 bytes
• Vendor ID: 0x1d6d (Unknown)
• Product ID: 0x104 (Unknown)
• Product version: 4.9
• Manufacturer: String descriptor 1 (unable to read)
• Product: AC Interface
• Serial Number: String descriptor 3 (unable to read)
• Configurations: 1