Documentation/devicetree/bindings/memory-controllers/exynos-srom.yaml

# SPDX-License-Identifier: GPL-2.0
%YAML 1.2
---
$id: http://devicetree.org/schemas/memory-controllers/exynos-srom.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#

title: Samsung Exynos SoC SROM Controller driver

maintainers:
  - Krzysztof Kozlowski <krzk@kernel.org>

description: |+
  The SROM controller can be used to attach external peripherals. In this case
  extra properties, describing the bus behind it, should be specified.

properties:
  compatible:
    items:
      - const: samsung,exynos4210-srom

  reg:
    maxItems: 1

  "#address-cells":
    const: 2

  "#size-cells":
    const: 1

  ranges:
    description: |
      Reflects the memory layout with four integer values per bank. Format:
      <bank-number> 0 <parent address of bank> <size>
      Up to four banks are supported.

patternProperties:
  "^.*@[0-3],[a-f0-9]+$":
    type: object
    description:
      The actual device nodes should be added as subnodes to the SROMc node.
      These subnodes, in addition to regular device specification, should
      contain the following properties, describing configuration
      of the relevant SROM bank.

    properties:
      reg:
        description:
          Bank number, base address (relative to start of the bank) and size
          of the memory mapped for the device. Note that base address will be
          typically 0 as this is the start of the bank.
        maxItems: 1

      reg-io-width:
        enum: [1, 2]
        description:
          Data width in bytes (1 or 2). If omitted, default of 1 is used.

      samsung,srom-page-mode:
        description:
          If page mode is set, 4 data page mode will be configured,
          else normal (1 data) page mode will be set.
        type: boolean

      samsung,srom-timing:
        $ref: /schemas/types.yaml#/definitions/uint32-array
        items:
          minItems: 6
          maxItems: 6
        description: |
          Array of 6 integers, specifying bank timings in the following order:
          Tacp, Tcah, Tcoh, Tacc, Tcos, Tacs.
          Each value is specified in cycles and has the following meaning
          and valid range:
          Tacp: Page mode access cycle at Page mode (0 - 15)
          Tcah: Address holding time after CSn (0 - 15)
          Tcoh: Chip selection hold on OEn (0 - 15)
          Tacc: Access cycle (0 - 31, the actual time is N + 1)
          Tcos: Chip selection set-up before OEn (0 - 15)
          Tacs: Address set-up before CSn (0 - 15)

    required:
      - reg
      - samsung,srom-timing

required:
  - compatible
  - reg

additionalProperties: false

examples:
  - |
    // Example: basic definition, no banks are configured
    memory-controller@12560000 {
        compatible = "samsung,exynos4210-srom";
        reg = <0x12560000 0x14>;
    };

  - |
    // Example: SROMc with SMSC911x ethernet chip on bank 3
    memory-controller@12570000 {
        #address-cells = <2>;
        #size-cells = <1>;
        ranges = <0 0 0x04000000 0x20000   // Bank0
                  1 0 0x05000000 0x20000   // Bank1
                  2 0 0x06000000 0x20000   // Bank2
                  3 0 0x07000000 0x20000>; // Bank3

        compatible = "samsung,exynos4210-srom";
        reg = <0x12570000 0x14>;

        ethernet@3,0 {
            compatible = "smsc,lan9115";
            reg = <3 0 0x10000>;     // Bank 3, offset = 0
            phy-mode = "mii";
            interrupt-parent = <&gpx0>;
            interrupts = <5 8>;
            reg-io-width = <2>;
            smsc,irq-push-pull;
            smsc,force-internal-phy;

            samsung,srom-page-mode;
            samsung,srom-timing = <9 12 1 9 1 1>;
        };
    };