I recently came across a device without any ALSA-level mixer controls,
everything was physical knobs on the hardware.
This patch enables that device to get a port too ("Analog Input").
Signed-off-by: David Henningsson <david.henningsson@canonical.com>
Completely rework mixer logic. This now allows controlling a full set of
elements from a single sink's volume slider/mute button.
This also introduces sink and source "ports" that can be used to choose
different input or output ports with the UI. (i.e. "mic"/"line-in" or
"speaker"/"headphones".
The mixer paths and device maps are now configered in external
configuration files and can be tweaked as necessary.