input: Extend matrix-keypad device tree binding
Some matrix keypad drivers can support different numbers of rows and
columns. Add a generic binding for these.
Implementation note:
In order to implement this binding in the kernel, we will need to modify
matrix_keypad_() to look up the number of rows and cols in
the keymap. Perhaps this could be done by passing 0 for these parameters?
Many of the parameters can already be set to NULL. Ick.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
diff --git a/Documentation/devicetree/bindings/input/matrix-keymap.txt b/Documentation/devicetree/bindings/input/matrix-keymap.txt
index 3cd8b98..c54919f 100644
--- a/Documentation/devicetree/bindings/input/matrix-keymap.txt
+++ b/Documentation/devicetree/bindings/input/matrix-keymap.txt
@@ -9,6 +9,12 @@
row << 24 | column << 16 | key-code
Optional properties:
+Properties for the number of rows and columns are optional because some
+drivers will use fixed values for these.
+- keypad,num-rows: Number of row lines connected to the keypad controller.
+- keypad,num-columns: Number of column lines connected to the keypad
+ controller.
+
Some users of this binding might choose to specify secondary keymaps for
cases where there is a modifier key such as a Fn key. Proposed names
for said properties are "linux,fn-keymap" or with another descriptive
@@ -17,3 +23,5 @@
Example:
linux,keymap = < 0x00030012
0x0102003a >;
+ keypad,num-rows = <2>;
+ keypad,num-columns = <8>;