Matrix_keypad with high capacity need a longer settle time after enable
all columns.
Add optional property to specify the settle time

Signed-off-by: Markus Burri <markus.burri@mt.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>

---
 .../devicetree/bindings/input/gpio-matrix-keypad.yaml       | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Documentation/devicetree/bindings/input/gpio-matrix-keypad.yaml b/Documentation/devicetree/bindings/input/gpio-matrix-keypad.yaml
index 0555c1e..408474e 100644
--- a/Documentation/devicetree/bindings/input/gpio-matrix-keypad.yaml
+++ b/Documentation/devicetree/bindings/input/gpio-matrix-keypad.yaml
@@ -57,6 +57,12 @@ properties:
       before we can scan keypad after activating column gpio.
     default: 0
 
+  all-cols-on-delay-us:
+    description:
+      Delay, measured in microseconds, that is needed
+      after activating all column gpios.
+    default: 0
+
   drive-inactive-cols:
     type: boolean
     description:
-- 
2.39.5