On Wed, 20 Jun 2018, Jason Thorpe wrote:
ofctl(8) is pretty useless for this purpose because it doesn't show you which driver instance has attached to a given device tree node. As for passing generic boot args, it's not obvious how one does that on the RPI (and I don't even see the hook that processes the generic boot args bcm283x_platform).
https://www.raspberrypi.org/documentation/configuration/cmdline-txt.md