The current driver is limited to checking if the adc value equals another
one with a hardcoded margin. This commit changes two aspects of that:
- the margin can be changed globally using IMX233_BUTTON_LRADC_MARGIN
and can also be overriden per button using the new LRADC_EX macro
- the lradc logic gained two comparison modes to check if the source
value is greater (or lower) than a threshold.
Change-Id: If1614451dafeae818a96e6f23a84e6731331ba03
This driver will subsume the old button-lradc driver and support far more
options. It can sense LRADC channels, PSWITCH, GPIOs and it handles special
"buttons" like headphone insertion and hold detection. It also provides a
more natural description of the buttons using a target-defined table with some
macros to make it easy to read and write. It uniformely handles debouncing on
LRADC channels and PSWITCH.
Change-Id: Ie61d1f593fdcf3bd456ba1d53a1fd784286834ce
