On Wed, Feb 20, 2013 at 7:27 PM, Anatolij Gustschin <agust@xxxxxxx> 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. > > Signed-off-by: Anatolij Gustschin <agust@xxxxxxx> > --- > v2: > - do not use inline attribute for matrix_keyboard_row_events(), > it causes reporting wrong events for some keys if the kernel > was built using gcc 4.7.2. > > .../bindings/input/gpio-matrix-keypad.txt | 7 ++ > drivers/input/keyboard/matrix_keypad.c | 112 ++++++++++++++++---- > include/linux/input/matrix_keypad.h | 6 + > 3 files changed, 106 insertions(+), 19 deletions(-) > > diff --git a/Documentation/devicetree/bindings/input/gpio-matrix-keypad.txt b/Documentation/devicetree/bindings/input/gpio-matrix-keypad.txt > index ead641c..57f4be3 100644 > --- a/Documentation/devicetree/bindings/input/gpio-matrix-keypad.txt > +++ b/Documentation/devicetree/bindings/input/gpio-matrix-keypad.txt > @@ -23,6 +23,13 @@ Optional Properties: > - debounce-delay-ms: debounce interval in milliseconds > - col-scan-delay-us: delay, measured in microseconds, that is needed > before we can scan keypad after activating column gpio > +- 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) > +- col-switch-delay-ms: column gpio switch interval for selecting alternative > + rows when using 'col-gpios-binary'. This is needed for > + periodical selecting of the alternative rows to be able > + to generate keypad interrupts for them This seems pretty loosely defined. Which rows are affected by this binary property? How common are matrix keypads wired this way, and do a lot of them use the same method? It seems to me that the device needs to be a lot more specific. g. -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
