Tiny TTY Driver for RHEL

I'm trying to write a tty driver for RHEL. My research has revealed tiny tty driver source code by Greg Kroah-Hartman. I figured I would start with that GPL v2 source code, compile a working baseline, and then make customizations to it in order to do what I need, again GPL v2.

However, there seem to be many differences in the include files for which that code was written and the include files in RHEL.

So, I'm wondering if there's any equivalent example tty driver source code for RHEL, perhaps specifically RHEL 7.4. It would be great if there was. Such would allow me to focus on the needed customizations rather than the linux version conversion.

[EDIT: This may relate substantially to a 2012 patch that moved buffers from tty_struct to tty_port...]

Thanks,
Helmut