USB Device Stack provides a unified framework of functions for standard device requests, CLASS requests, VENDOR requests and custom special requests. The object-oriented and chained approach allows the user to quickly get started with composite devices without having to worry about the underlying logic. At the same time, a standard dcd porting interface has been standardised for adapting different USB IPs to achieve ip-oriented programming.
The USB Host Stack has a standard enumeration implementation for devices mounted on roothubs and external hubs, and a standard interface for the different Class to indicate what the Class driver needs to do after enumeration and after disconnection. A standard hcd porting interface has also been standardised for adapting different USB IPs for IP-oriented programming. Finally, the protocol stack is managed using os, and provides osal to make a adaptation to different os.
How USB Host Stack is implemented, the video will be provided in future.
USB Host Stack has the following functions：
- Automatic loading of supported Class drivers
- Support blocking transfers and asynchronous transfers
- Support Compound and Composite Device
- Multi-level HUB support, expandable up to 7 levels
- Support Communication Device Class (CDC)
- Support Human Interface Device (HID)
- Support Mass Storage Class (MSC)
- Support Vendor class
- Support Andriod AOA Communication
The USB Host stack also provides the lsusb function, which allows you to view information about all mounted devices, including those on external hubs, with the help of a shell plugin.
