xref: /openbmc/linux/Documentation/devicetree/bindings/serial/amlogic,meson-uart.yaml (revision 4df7e9a1)

# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
# Copyright 2019 BayLibre, SAS
%YAML 1.2
---
$id: "http://devicetree.org/schemas/serial/amlogic,meson-uart.yaml#"
$schema: "http://devicetree.org/meta-schemas/core.yaml#"

title: Amlogic Meson SoC UART Serial Interface

maintainers:
  - Neil Armstrong <narmstrong@baylibre.com>

description: |
  The Amlogic Meson SoC UART Serial Interface is present on a large range
  of SoCs, and can be present either in the "Always-On" power domain or the
  "Everything-Else" power domain.

  The particularity of the "Always-On" Serial Interface is that the hardware
  is active since power-on and does not need any clock gating and is usable
  as very early serial console.

properties:
  compatible:
    oneOf:
      - description: Always-on power domain UART controller
        items:
        - enum:
          - amlogic,meson6-uart
          - amlogic,meson8-uart
          - amlogic,meson8b-uart
          - amlogic,meson-gx-uart
        - const: amlogic,meson-ao-uart
      - description: Everything-Else power domain UART controller
        enum:
        - amlogic,meson6-uart
        - amlogic,meson8-uart
        - amlogic,meson8b-uart
        - amlogic,meson-gx-uart

  reg:
    maxItems: 1

  interrupts:
    maxItems: 1

  clocks:
    items:
      - description: external xtal clock identifier
      - description: the bus core clock, either the clk81 clock or the gate clock
      - description: the source of the baudrate generator, can be either the xtal or the pclk

  clock-names:
    items:
      - const: xtal
      - const: pclk
      - const: baud

required:
  - compatible
  - reg
  - interrupts
  - clocks
  - clock-names

examples:
  - |
    serial@84c0 {
          compatible = "amlogic,meson-gx-uart";
          reg = <0x84c0 0x14>;
          interrupts = <26>;
          clocks = <&xtal>, <&pclk>, <&xtal>;
          clock-names = "xtal", "pclk", "baud";
    };