On 02/20/2013 12:27 PM, Anatolij Gustschin wrote:

On hardware with limited gpios one column select gpio can select
two different rows when using some additional hardware logic:
high value selects one row, low value selects another row. Add
support for such matrix keyboards and document device tree
bindings used to describe them.

Since half of the columns is always not selected, interrupts won't be
generated for press events on these columns. To generate interrupts
for not selected columns we need to periodicaly switch to these columns
in order to catch the potential press events. This is done by additional
work function.

+- col-gpios-binary:	specify that high and low states of a column gpio
+			select two different rows (boards with limited gpios
+			could support this by additional hardware logic)

1 GPIO and 2 columns is essentially a special case with a 1->2 line decoder.

Do the binding definition and code work fine if you have e.g. 3 GPIOs,
and a 3->8 decoder in order to support 8 columns?