I have a machine installed with OpenELEC and I'd like to use the motherboard line input (jack) and redirect sound through the HDMI link. All the other jacks from the motherboard will be unused.

I tried playing with alsamixer (booting the machine with a LiveCD since OpenELEC has no ALSA mixer application) but all I can get is sound going out through the output jack. With Kodi I can use any HDMI link I wish as the main output but I have come to wondering if both sound hardware can interact...

Input is made through Intel HDA Realtek ALC892. HDMI is an Intel Haswell HDMI.