We should probably look into starting a new thread for that, because we’re getting pretty off-topic here 
But I’m looking into it further as we speak and I’m getting the sense that most of the support we require already exists mainline.
There currently isn’t a driver for the Touchscreen (Focaltech FTS8201) but the upstream kernel has a driver for that brand of touchscreen controllers (edt-ft5x06.c « touchscreen « input « drivers - kernel/git/torvalds/linux.git - Linux kernel source tree) that seems to work with other models as well, so it’s worth a shot.
Same goes for the audio codec (TAS5825M) where a device from the family (TAS5805M) is supported mainline.
Other than that most everything else, I assume, should work.