I've raised a pull request with a port to ath79 for my D-Link DIR-825-C1 (Link). I included support for DIR-835-A1 as well, as it's included also in the "mach" file for ar71xx.
The two routers are similar, except for some LEDs. Anyway, I don't have an 835 myself, so I would be glad if somebody could test this. I'd be interested in knowing if it works in general (it should) and especially if the interfaces get the correct MAC addresses and if the LEDs are fine.
It'd be cool if I could get some feedback on the DIR-835-A1. My mail address is in the pull request.