CAN driver - How do I use it?

Hey everybody!

I would like to use CANBUS to connect some custom hardware to px4. While I easily implemented CAN on my application hardware using HAL-library, I find it very confusing and just am not able to wrap my head around the CAN-drivers in ArduPilot. Not to speak of implementing UAVCAN.

I searched the documentation for CAN specific detail but information was scarce.

Is there somebody out there who can sketch up how to use the px4-CAN-driver? Without UAVCAN, that is.

Thank you a lot!