Hi Jun,

The OTG_HS USB on my board is working with a modified version of the earlier usb_dc_stm32.c on zephyr 1.9. (usb_dc_stm32.c was actually imported from a PR which had not been merged.). We did some modifications to make it work for the OTG_HS port. I can forward that modified file to you if you'd like to take a look. Also, You should be the right person to integrate this feature since most changes on the latest usb_dc_stm32.c come from you.

I' ll check the file and try to find a way to integrate it in the usb_dc_stm32 driver.
I' ll try to do it asap but as I work on zephyr on my free time, it may take a while.

Yannis