This is a work-in-progress embassy-usb-driver for ESP32-S3 and ESP32-S2 chips.

I have written a C++ USB implementation for these chips in the past (https://github.com/simpkins/ausb), and this code was created through a mix of porting the ESP32 logic to Rust, and partly from looking at the embassy-stm32 crate for examples of an existing embassy-usb-driver.

This code isn't quite complete yet, and there are still plenty of TODOs in the code, but the HID example generally appears to function as expected.

Ideally this code probably should be unified with the embassy-stm32 implementation, since the USB core is the same. The main item that needs to be resolved first is just the different register access APIs for the esp-hal vs the stm32 registers. We should be able to just pick one API however and cast the register block address to the desired type. At some point I might try and look to see what parts of this implementation are worth upstreaming into the embassy-stm32 implementation.