This is not a complete guide. But a start for future discussions.
As far as we know, companies may or may not include touchscreen drivers in the kernel. In such situations, experts analyze the kernel and modify it to include the correct driver and try to make the touch screen work. If you've seen the situation happen and you don't have extra touchscreen driver files, go to the links to learn about it or ask for help:
How to modify a (Meditek) Android kernel - github thanks for @ADeadTrousers