Input: of_keymap - add device tree bindings for simple key matrices

This adds a simple device tree binding for simple key matrix data and
a helper to fill in the platform data.

Signed-off-by: Olof Johansson <olof@lixom.net>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

1 files changed, 19 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/input/matrix-keymap.txt b/Documentation/devicetree/bindings/input/matrix-keymap.txt
new file mode 100644
index 00000000000..3cd8b98ccd2
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+++ b/Documentation/devicetree/bindings/input/matrix-keymap.txt
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+A simple common binding for matrix-connected key boards. Currently targeted at
+defining the keys in the scope of linux key codes since that is a stable and
+standardized interface at this time.
+
+Required properties:
+- linux,keymap: an array of packed 1-cell entries containing the equivalent
+  of row, column and linux key-code. The 32-bit big endian cell is packed
+  as:
+	row << 24 | column << 16 | key-code
+
+Optional properties:
+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
+word for the modifier other from "Fn".
+
+Example:
+	linux,keymap = < 0x00030012
+			 0x0102003a >;