Is there an i.MX8 HDMI TX driver that works with Etnaviv?

[Bernhard Rosenkraenzer]

Hi,
I'm trying to get etnaviv up and running on an i.MX8 based Hummingboard Pulse, on top of kernel 5.5-rc7.
Everything looks good, etnaviv loads and recognizes the GC7000 correctly:

[Sun Jan 26 00:32:40 2020] etnaviv etnaviv: bound 38000000.gpu (ops gpu_ops [etnaviv])
[Sun Jan 26 00:32:40 2020] etnaviv-gpu 38000000.gpu: model: GC7000, revision: 6214
[Sun Jan 26 00:32:40 2020] [drm] Initialized etnaviv 1.3.0 20151214 for etnaviv on minor 0

Opening /dev/dri/card0 etc. works too - but of course there's no signal on the HDMI port given there's no HDMI TX driver in 5.5-rc7 (at least none that I could find).
Is there any out of tree driver that will work (or could be made work) on 5.5 without insane amounts of effort?

Thanks
bero