Commit 52dc6d3b authored by Stephen Boyd's avatar Stephen Boyd Committed by Dmitry Torokhov
Browse files

dt-bindings: google,cros-ec-keyb: Introduce switches only compatible 



If the ChromeOS board is a detachable, this cros-ec-keyb device won't
have a matrix keyboard but it may have some button switches, e.g. volume
buttons and power buttons. The driver still registers a keyboard though
and that leads to userspace confusion around where the keyboard is.

We tried to work around this by only registering the keyboard device when
rows/columns properties were specified for the device, but that led to
another problem where removing the rows/columns properties breaks the
existing binding. Technically before that commit the rows/columns
properties were required, otherwise the driver would fail to probe.
Removing the properties from devicetrees makes the driver fail to probe
unless the corresponding driver patch is present. Furthermore, this makes
requiring matrix keyboard properties for devices that really have a
keyboard impossible because the compatible drives the schema and now the
properties are optional.

Add a more specific compatible for this type of device that indicates to
the OS that there are only switches and no matrix keyboard present.

Reviewed-by: default avatarKrzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: default avatarDouglas Anderson <dianders@chromium.org>
Signed-off-by: default avatarStephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20220516183452.942008-2-swboyd@chromium.org


Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
parent f443e374

Documentation/devicetree/bindings/input/google,cros-ec-keyb.yaml

+33 −6
Original line number Diff line number Diff line
@@ -15,14 +15,18 @@ description: | 
  Google's ChromeOS EC Keyboard is a simple matrix keyboard

  implemented on a separate EC (Embedded Controller) device. It provides

  a message for reading key scans from the EC. These are then converted

  into keycodes for processing by the kernel.



allOf:

  - $ref: "/schemas/input/matrix-keymap.yaml#"

  into keycodes for processing by the kernel. This device also supports

  switches/buttons like power and volume buttons.



properties:

  compatible:

    const: google,cros-ec-keyb

    anyOf:

      - description: ChromeOS EC with only buttons/switches

      - items:

          - const: google,cros-ec-keyb-switches

      - description: ChromeOS EC with keyboard and possibly buttons/switches

      - items:

          - const: google,cros-ec-keyb



  google,needs-ghost-filter:

    description:
@@ -41,15 +45,32 @@ properties: 
      where the lower 16 bits are reserved. This property is specified only

      when the keyboard has a custom design for the top row keys.



dependencies:

  function-row-phsymap: [ 'linux,keymap' ]

  google,needs-ghost-filter: [ 'linux,keymap' ]



required:

  - compatible



if:

  properties:

    compatible:

      contains:

        const: google,cros-ec-keyb

then:

  allOf:

    - $ref: "/schemas/input/matrix-keymap.yaml#"

  required:

    - keypad,num-rows

    - keypad,num-columns

    - linux,keymap



unevaluatedProperties: false



examples:

  - |

    #include <dt-bindings/input/input.h>

    cros-ec-keyb {

    keyboard-controller {

        compatible = "google,cros-ec-keyb";

        keypad,num-rows = <8>;

        keypad,num-columns = <13>;
@@ -113,3 +134,9 @@ examples: 
            /* UP      LEFT    */

            0x070b0067 0x070c0069>;

    };

  - |

    /* No matrix keyboard, just buttons/switches */

    keyboard-controller {

        compatible = "google,cros-ec-keyb-switches";

    };

...