Kernel source location

[aragats]

Hi all!
I'm new here, and I'm a new and happy user of Ubuntu Touch in my Xiaomi Mi A2.
I'd like to port in a driver (kernel module), but I'm having hard time finding the kernel's source code. Probably I missed something obvious, please forgive my ignorance.

Thanks for directions!

[farkasdvd]

I would start here:
https://gitlab.com/ubports/community-ports/android9/xiaomi-mi-a2/xiaomi-jasmine_sprout