VORTEX_MIXER_CHNBASE
hwwrite(vortex->mmio, VORTEX_MIXER_CHNBASE + (ch << 2), mix);
prev = VORTEX_MIXER_CHNBASE + (ch << 2);
ebp = VORTEX_MIXER_CHNBASE + (ch << 2);
VORTEX_MIXER_CHNBASE +