linux_dsm_epyc7002/Documentation/devicetree/bindings/input/matrix-keymap.txt
Simon Glass 1d0b1c74ed 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>
2013-02-08 12:58:40 +00:00

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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:
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
word for the modifier other from "Fn".
Example:
linux,keymap = < 0x00030012
0x0102003a >;
keypad,num-rows = <2>;
keypad,num-columns = <8>;