It is supported but not defined in device tree.
There has just been a patch set merged upstream (ie probably 4.19) that allows panel devices to fail to probe without causing the entire display stack to fail. Without that it was a bit of a mess if you'd defined it but the connector fell out or similar.
See https://github.com/anholt/linux/wiki/Ra ... lay-panels
for a description of how to add DSI devices to DT for the drm driver, and commits on https://github.com/anholt/linux/commits/drm-vc4-misc
that should get the panel working (I guess they ought to be merged into an overlay at some point).
Software Engineer at Raspberry Pi Trading. Views expressed are still personal views.
I'm not interested in doing contracts for bespoke functionality - please don't ask.