Commit e469b87e authored by Bastien Curutchet (Schneider Electric)'s avatar Bastien Curutchet (Schneider Electric) Committed by Jakub Kicinski
Browse files

dt-bindings: net: dsa: microchip: Add strap description to set SPI mode 



At reset, KSZ8463 uses a strap-based configuration to set SPI as
interface bus. If the required pull-ups/pull-downs are missing (by
mistake or by design to save power) the pins may float and the
configuration can go wrong preventing any communication with the switch.

Add a 'reset' pinmux state
Add a KSZ8463 specific strap description that can be used by the driver
to drive the strap pins during reset. Two GPIOs are used. Users must
describe either both of them or none of them.

Signed-off-by: default avatarBastien Curutchet (Schneider Electric) <bastien.curutchet@bootlin.com>
Reviewed-by: default avatarRob Herring (Arm) <robh@kernel.org>
Link: https://patch.msgid.link/20250918-ksz-strap-pins-v3-2-16662e881728@bootlin.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 6bd5b729

Documentation/devicetree/bindings/net/dsa/microchip,ksz.yaml

+19 −0
Original line number Diff line number Diff line
@@ -34,6 +34,13 @@ properties: 
      - microchip,ksz8567

      - microchip,lan9646



  pinctrl-names:

    items:

      - const: default

      - const: reset

        description:

          Used during reset for strap configuration.



  reset-gpios:

    description:

      Should be a gpio specifier for a reset line.
@@ -139,6 +146,18 @@ allOf: 
                    should be provided externally.

              dependencies:

                microchip,rmii-clk-internal: [ethernet]

  - if:

      properties:

        compatible:

          contains:

            const: microchip,ksz8463

    then:

      properties:

        straps-rxd-gpios:

          description:

            RXD0 and RXD1 pins, used to select SPI as bus interface.

          minItems: 2

          maxItems: 2



unevaluatedProperties: false