touch screen API resources?

[wibble]

I guess you're looking to provide an alternative to the usual on-screen keyboard, in which case the squeekboard docs are probably a good place to start:
https://developer.puri.sm/Librem5/Softwa...board.html

I'll take a look, but by way of context, this would normally be used by blind folks, so the screen image aspects aren't all that critical.

I was thinking more in terms of how it maps touch inputs to keyboard input for weyland. Without knowing more about what you're aiming to do it's hard to know whether you'd be looking at accessing the kernel driver interface directly (under /dev/input/ I expect) or providing an alternate input method at the X or wayland level to use existing desktops with their respective accessibility features. Each has a different way of doing things.