The android headset specification expect buttons impedance:
A (MEDIA) 0-70 Ohm
D (VOICECOMMAND) 110-180 Ohm
B (VOLUMEUP) 210-290 Ohm
C (VOLUMEDOWN) 360-680 Ohm
Thus key mapping should be
key1 - MEDIA
key2 - VOICECOMMAND
key3 - VOLUMEUP
key3 - VOLUMEDOWN
Signed-off-by: Anatol Pomozov <anatol.pomozov@gmail.com> Acked-by: Dylan Reid <dgreid@chromium.org> Signed-off-by: Mark Brown <broonie@kernel.org>