Function audio_mux() actually deals with two types of mute: gpio mute and subdevice muting. This patch claryfies the meaning of these values, but mainly prepares the code for the next patch. Signed-off-by: Frank Schäfer <fschaefer.oss@googlemail.com> Acked-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>