Hardware assisted video decoding on Radeon KMS driver?

[ralph]

I have an AMD C-70 APU with a Radeon HD 7290 GPU, which seems to be a
6290 clone with an UVD3 video decoding chip. It's been years and this
feature has yet to be implemented. Or is it supposed to work with the
KMS driver? Everything else seems to work perfectly for me (most of the
time, sometimes starting X just hangs and sometimes it's not
accelerated until I reboot).

If it still hasn't been implemented, then why? Is anyone working on it?
Any hope for the near future? I'd love to help with whatever I can.