linux/Documentation/devicetree/bindings/memory-controllers/samsung,exynos5422-dmc.yaml

# SPDX-License-Identifier: GPL-2.0
%YAML 1.2
---
$id: http://devicetree.org/schemas/memory-controllers/samsung,exynos5422-dmc.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#

title: |
  Samsung Exynos5422 SoC frequency and voltage scaling for Dynamic Memory
  Controller device

maintainers:
  - Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
  - Lukasz Luba <lukasz.luba@arm.com>

description: |
  The Samsung Exynos5422 SoC has DMC (Dynamic Memory Controller) to which the
  DRAM memory chips are connected. The driver is to monitor the controller in
  runtime and switch frequency and voltage. To monitor the usage of the
  controller in runtime, the driver uses the PPMU (Platform Performance
  Monitoring Unit), which is able to measure the current load of the memory.
  When 'userspace' governor is used for the driver, an application is able to
  switch the DMC and memory frequency.

properties:
  compatible:
    items:
      - const: samsung,exynos5422-dmc

  clock-names:
    items:
      - const: fout_spll
      - const: mout_sclk_spll
      - const: ff_dout_spll2
      - const: fout_bpll
      - const: mout_bpll
      - const: sclk_bpll
      - const: mout_mx_mspll_ccore
      - const: mout_mclk_cdrex

  clocks:
    minItems: 8
    maxItems: 8

  devfreq-events:
    $ref: '/schemas/types.yaml#/definitions/phandle-array'
    minItems: 1
    maxItems: 16
    items:
      maxItems: 1
    description: phandles of the PPMU events used by the controller.

  device-handle:
    $ref: '/schemas/types.yaml#/definitions/phandle'
    description: |
      phandle of the connected DRAM memory device. For more information please
      refer to jedec,lpddr3.yaml.

  operating-points-v2: true

  interrupts:
    items:
      - description: DMC internal performance event counters in DREX0
      - description: DMC internal performance event counters in DREX1

  interrupt-names:
    items:
      - const: drex_0
      - const: drex_1

  reg:
    items:
      - description: registers of DREX0
      - description: registers of DREX1

  samsung,syscon-clk:
    $ref: '/schemas/types.yaml#/definitions/phandle'
    description: |
      Phandle of the clock register set used by the controller, these registers
      are used for enabling a 'pause' feature and are not exposed by clock
      framework but they must be used in a safe way.  The register offsets are
      in the driver code and specyfic for this SoC type.

  vdd-supply: true

required:
  - compatible
  - clock-names
  - clocks
  - devfreq-events
  - device-handle
  - reg
  - samsung,syscon-clk

additionalProperties: false

examples:
  - |
    #include <dt-bindings/clock/exynos5420.h>
    ppmu_dmc0_0: ppmu@10d00000 {
        compatible = "samsung,exynos-ppmu";
        reg = <0x10d00000 0x2000>;
        clocks = <&clock CLK_PCLK_PPMU_DREX0_0>;
        clock-names = "ppmu";
        events {
            ppmu_event_dmc0_0: ppmu-event3-dmc0-0 {
                event-name = "ppmu-event3-dmc0_0";
            };
        };
    };

    memory-controller@10c20000 {
        compatible = "samsung,exynos5422-dmc";
        reg = <0x10c20000 0x10000>, <0x10c30000 0x10000>;
        clocks = <&clock CLK_FOUT_SPLL>,
                 <&clock CLK_MOUT_SCLK_SPLL>,
                 <&clock CLK_FF_DOUT_SPLL2>,
                 <&clock CLK_FOUT_BPLL>,
                 <&clock CLK_MOUT_BPLL>,
                 <&clock CLK_SCLK_BPLL>,
                 <&clock CLK_MOUT_MX_MSPLL_CCORE>,
                 <&clock CLK_MOUT_MCLK_CDREX>;
        clock-names = "fout_spll",
                      "mout_sclk_spll",
                      "ff_dout_spll2",
                      "fout_bpll",
                      "mout_bpll",
                      "sclk_bpll",
                      "mout_mx_mspll_ccore",
                      "mout_mclk_cdrex";
        operating-points-v2 = <&dmc_opp_table>;
        devfreq-events = <&ppmu_event3_dmc0_0>,	<&ppmu_event3_dmc0_1>,
                         <&ppmu_event3_dmc1_0>, <&ppmu_event3_dmc1_1>;
        device-handle = <&samsung_K3QF2F20DB>;
        vdd-supply = <&buck1_reg>;
        samsung,syscon-clk = <&clock>;
        interrupt-parent = <&combiner>;
        interrupts = <16 0>, <16 1>;
        interrupt-names = "drex_0", "drex_1";
    };