External comp driver for custom hostmot2 module

Hello,
I'm currently in the process of creating a new module for the 7i80 FPGA, and realizing that I also need to add a driver on the LinuxCNC side. Since the module is pretty niche, I'm trying to avoid modifying the entire Hostmot2 driver (and then worry about having to maintain my local copy against master every time there's a version change), so I was wondering if it was possible to write a driver for Hostmot2 as an external comp. I've seen the mesa_7i65.comp and mesa_uart.comp examples, but I'm more interested in the low level register access (eg. how the inmux driver communicates with the inmux module on the FPGA).
Thanks,
James H.