I have a similar poblem and I hope you can maybe help me out.
I also wan't to work with a SPI to CANFD device on the Raspberry Pi. The board I'm working is also using the MCP2517FD/MCP2518FD for CAN communication, which is how I stumbled on your thread. Can you maybe walk me through how the compilation of the driver works, since that is where I'm stuck. I haven't been able to get any other drivers I have found for the MCP2517FD to work, which is why I'm hoping this one will.
Thanks in advance