linux/Documentation/devicetree/bindings/memory-controllers/mediatek,smi-common.yaml

# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
# Copyright (c) 2020 MediaTek Inc.
%YAML 1.2
---
$id: http://devicetree.org/schemas/memory-controllers/mediatek,smi-common.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#

title: SMI (Smart Multimedia Interface) Common

maintainers:
  - Yong Wu <yong.wu@mediatek.com>

description: |
  The hardware block diagram please check bindings/iommu/mediatek,iommu.yaml

  MediaTek SMI have two generations of HW architecture, here is the list
  which generation the SoCs use:
  generation 1: mt2701 and mt7623.
  generation 2: mt2712, mt6779, mt8167, mt8173, mt8183 and mt8192.

  There's slight differences between the two SMI, for generation 2, the
  register which control the iommu port is at each larb's register base. But
  for generation 1, the register is at smi ao base(smi always on register
  base). Besides that, the smi async clock should be prepared and enabled for
  SMI generation 1 to transform the smi clock into emi clock domain, but that is
  not needed for SMI generation 2.  

properties:
  compatible:
    oneOf:
      - enum:
          - mediatek,mt2701-smi-common
          - mediatek,mt2712-smi-common
          - mediatek,mt6779-smi-common
          - mediatek,mt8167-smi-common
          - mediatek,mt8173-smi-common
          - mediatek,mt8183-smi-common
          - mediatek,mt8192-smi-common

      - description: for mt7623
        items:
          - const: mediatek,mt7623-smi-common
          - const: mediatek,mt2701-smi-common

  reg:
    maxItems: 1

  power-domains:
    maxItems: 1

  clocks:
    description: |
      apb and smi are mandatory. the async is only for generation 1 smi HW.
      gals(global async local sync) also is optional, see below.      
    minItems: 2
    items:
      - description: apb is Advanced Peripheral Bus clock, It's the clock for
          setting the register.
      - description: smi is the clock for transfer data and command.
      - description: Either asynchronous clock to help transform the smi clock
          into the emi clock domain on Gen1 h/w, or the path0 clock of gals.
      - description: gals1 is the path1 clock of gals.

  clock-names:
    minItems: 2
    maxItems: 4

required:
  - compatible
  - reg
  - power-domains
  - clocks
  - clock-names

allOf:
  - if:  # only for gen1 HW
      properties:
        compatible:
          contains:
            enum:
              - mediatek,mt2701-smi-common
    then:
      properties:
        clock:
          items:
            minItems: 3
            maxItems: 3
        clock-names:
          items:
            - const: apb
            - const: smi
            - const: async

  - if:  # for gen2 HW that have gals
      properties:
        compatible:
          enum:
            - mediatek,mt6779-smi-common
            - mediatek,mt8183-smi-common
            - mediatek,mt8192-smi-common

    then:
      properties:
        clock:
          items:
            minItems: 4
            maxItems: 4
        clock-names:
          items:
            - const: apb
            - const: smi
            - const: gals0
            - const: gals1

    else:  # for gen2 HW that don't have gals
      properties:
        clock:
          items:
            minItems: 2
            maxItems: 2
        clock-names:
          items:
            - const: apb
            - const: smi

additionalProperties: false

examples:
  - |+
    #include <dt-bindings/clock/mt8173-clk.h>
    #include <dt-bindings/power/mt8173-power.h>

    smi_common: smi@14022000 {
            compatible = "mediatek,mt8173-smi-common";
            reg = <0x14022000 0x1000>;
            power-domains = <&scpsys MT8173_POWER_DOMAIN_MM>;
            clocks = <&mmsys CLK_MM_SMI_COMMON>,
                     <&mmsys CLK_MM_SMI_COMMON>;
            clock-names = "apb", "smi";
    };