xref: /openbmc/linux/Documentation/devicetree/bindings/mfd/google,cros-ec.yaml (revision 46b57806)

# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/mfd/google,cros-ec.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#

title: ChromeOS Embedded Controller

maintainers:
  - Benson Leung <bleung@chromium.org>
  - Enric Balletbo i Serra <enric.balletbo@collabora.com>
  - Guenter Roeck <groeck@chromium.org>

description:
  Google's ChromeOS EC is a microcontroller which talks to the AP and
  implements various functions such as keyboard and battery charging.
  The EC can be connected through various interfaces (I2C, SPI, and others)
  and the compatible string specifies which interface is being used.

properties:
  compatible:
    oneOf:
      - description:
          For implementations of the EC is connected through I2C.
        const: google,cros-ec-i2c
      - description:
          For implementations of the EC is connected through SPI.
        const: google,cros-ec-spi
      - description:
          For implementations of the EC is connected through RPMSG.
        const: google,cros-ec-rpmsg

  google,cros-ec-spi-pre-delay:
    description:
      This property specifies the delay in usecs between the
      assertion of the CS and the first clock pulse.
    allOf:
      - $ref: /schemas/types.yaml#/definitions/uint32
      - default: 0
      - minimum: 0

  google,cros-ec-spi-msg-delay:
    description:
      This property specifies the delay in usecs between messages.
    allOf:
      - $ref: /schemas/types.yaml#/definitions/uint32
      - default: 0
      - minimum: 0

  google,has-vbc-nvram:
    description:
      Some implementations of the EC include a small nvram space used to
      store verified boot context data. This boolean flag is used to specify
      whether this nvram is present or not.
    type: boolean

  spi-max-frequency:
    description: Maximum SPI frequency of the device in Hz.

  reg:
    maxItems: 1

  interrupts:
    maxItems: 1

required:
  - compatible

if:
  properties:
    compatible:
      contains:
        enum:
          - google,cros-ec-i2c
          - google,cros-ec-rpmsg
then:
  properties:
    google,cros-ec-spi-pre-delay: false
    google,cros-ec-spi-msg-delay: false
    spi-max-frequency: false

additionalProperties: false

examples:
  # Example for I2C
  - |
    #include <dt-bindings/gpio/gpio.h>
    #include <dt-bindings/interrupt-controller/irq.h>

    i2c0 {
        #address-cells = <1>;
        #size-cells = <0>;

        cros-ec@1e {
            compatible = "google,cros-ec-i2c";
            reg = <0x1e>;
            interrupts = <6 0>;
            interrupt-parent = <&gpio0>;
        };
    };

  # Example for SPI
  - |
    #include <dt-bindings/gpio/gpio.h>
    #include <dt-bindings/interrupt-controller/irq.h>

    spi0 {
        #address-cells = <1>;
        #size-cells = <0>;

        cros-ec@0 {
            compatible = "google,cros-ec-spi";
            reg = <0x0>;
            google,cros-ec-spi-msg-delay = <30>;
            google,cros-ec-spi-pre-delay = <10>;
            interrupts = <99 0>;
            interrupt-parent = <&gpio7>;
            spi-max-frequency = <5000000>;
        };
    };

  # Example for RPMSG
  - |
    scp0 {
        cros-ec {
            compatible = "google,cros-ec-rpmsg";
        };
    };
...