ASoC: WCD9310: Read microphone voltage on headset removal and button press

Blowing loudly into the microphone can change the voltage
enough to signal button press or headset removal interrupts.
Using a more accurate voltage measurement will verify that
button press interrupts and headset removal interrupts are
signifying the correct events.

Also fixes the issue of removing a mic-less headphone
during audio playback by enabling removal detection through
the microphone for headphones. Also makes sure that the
HPH power amplifier doesn't trigger a headset removal event.

CRs-fixed: 298613
Signed-off-by: Brad Rubin <brubin@codeaurora.org>
1 file changed