In most devices, the button ladder is not actually derived from VDDIO but
from a constant voltage source, making it very easy to read it. However on
some devices like ther ZEN X-Fi Style, the ladder is wired to VDDIO we
can be changed so it's crucial that the button driver correctly scales the
values wrt VDDIO.
Change-Id: Ifc11abe2838fa7d16d0d60ecd96964a8dc5ea6d7
The driver can now handle HOLD in several ways, including using a GPIO.
Also add a debug routine to read the raw value of the adc.
Change-Id: Ide2cb1ac58e759b4bc464e606b432f2c150ee36f
This driver does debouncing and best lradc usage and only requires
a sorted table of values to work, this factoring code as much as
possible.
Change-Id: I84b46f4b08094634e1c5deb5ca9ba20763389e66
