There is a native cx5530 audio driver, but it's for FreeBSD. http://63.249.85.132/gx_audio/index.html http://alumni.cse.ucsc.edu/~brucem/gx_audio/ It may just need to be ported over to linux if it hasn't been already.
Also, the latest kernels no longer use durango in the framebuffer driver. It may be possible to port it to linuxbios and dispense with VGA and even VSA altogether, which I think has been the goal for a long time.
Bryan