[PATCH v8] Add matrix keypad driver support for Mediatek SoCs

[Fengping Yu]

Change since v7:
- specify compatible property as const string
- add maxItem in required property
- squash keypad example nodes
- sort header file with alphabetic order
- align all define values and add MTK_ prefix to make more uniform
- change debounce value to default 16ms if not specified in dts
- remove extra braces
- separate clk prepare as an internal driver function
- add special compatible string
- modify CONFIG_KEYBOARD_MTK_KPD=m to build keypad as ko module

fengping.yu (3):
  dt-bindings: Add keypad devicetree documentation
  drivers: input: keyboard: Add mtk keypad driver
  configs: defconfig: Add CONFIG_ng.yu (3):
  dt-bindings: Add keypad devicetree documentation
  drivers: input: keyboard: Add mtk keypad driver
  configs: defconfig: Add CONFIG_KEYBOARD_MTK_KPD=m

 .../devicetree/bindings/input/mtk-kpd.yaml    |  94 +++++++
 arch/arm64/configs/defconfig                  |   1 +
 drivers/input/keyboard/Kconfig                |   9 +
 drivers/input/keyboard/Makefile               |   1 +
 drivers/input/keyboard/mtk-kpd.c              | 231 ++++++++++++++++++
 5 files changed, 336 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/input/mtk-kpd.yaml
 create mode 100644 drivers/input/keyboard/mtk-kpd.c

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2.18.0