kernel/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra186-mc.yaml

# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/memory-controllers/nvidia,tegra186-mc.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#

title: NVIDIA Tegra186 (and later) SoC Memory Controller

maintainers:
  - Jon Hunter <jonathanh@nvidia.com>
  - Thierry Reding <thierry.reding@gmail.com>

description: |
  The NVIDIA Tegra186 SoC features a 128 bit memory controller that is split
  into four 32 bit channels to support LPDDR4 with x16 subpartitions. The MC
  handles memory requests for 40-bit virtual addresses from internal clients
  and arbitrates among them to allocate memory bandwidth.

  Up to 15 GiB of physical memory can be supported. Security features such as
  encryption of traffic to and from DRAM via general security apertures are
  available for video and other secure applications, as well as DRAM ECC for
  automotive safety applications (single bit error correction and double bit
  error detection).

properties:
  $nodename:
    pattern: "^memory-controller@[0-9a-f]+$"

  compatible:
    items:
      - enum:
          - nvidia,tegra186-mc
          - nvidia,tegra194-mc

  reg:
    maxItems: 1

  interrupts:
    maxItems: 1

  "#address-cells":
    const: 2

  "#size-cells":
    const: 2

  ranges: true

  dma-ranges: true

patternProperties:
  "^external-memory-controller@[0-9a-f]+$":
    description:
      The bulk of the work involved in controlling the external memory
      controller on NVIDIA Tegra186 and later is performed on the BPMP. This
      coprocessor exposes the EMC clock that is used to set the frequency at
      which the external memory is clocked and a remote procedure call that
      can be used to obtain the set of available frequencies.
    type: object
    properties:
      compatible:
        items:
          - enum:
              - nvidia,tegra186-emc
              - nvidia,tegra194-emc

      reg:
        maxItems: 1

      interrupts:
        maxItems: 1

      clocks:
        items:
          - description: external memory clock

      clock-names:
        items:
          - const: emc

      nvidia,bpmp:
        $ref: /schemas/types.yaml#/definitions/phandle
        description:
          phandle of the node representing the BPMP

required:
  - compatible
  - reg
  - interrupts
  - "#address-cells"
  - "#size-cells"

additionalProperties: false

examples:
  - |
    #include <dt-bindings/clock/tegra186-clock.h>
    #include <dt-bindings/interrupt-controller/arm-gic.h>

    bus {
        #address-cells = <2>;
        #size-cells = <2>;

        memory-controller@2c00000 {
            compatible = "nvidia,tegra186-mc";
            reg = <0x0 0x02c00000 0x0 0xb0000>;
            interrupts = <GIC_SPI 223 IRQ_TYPE_LEVEL_HIGH>;

            #address-cells = <2>;
            #size-cells = <2>;

            ranges = <0x0 0x02c00000 0x0 0x02c00000 0x0 0xb0000>;

            /*
             * Memory clients have access to all 40 bits that the memory
             * controller can address.
             */
            dma-ranges = <0x0 0x0 0x0 0x0 0x100 0x0>;

            external-memory-controller@2c60000 {
                compatible = "nvidia,tegra186-emc";
                reg = <0x0 0x02c60000 0x0 0x50000>;
                interrupts = <GIC_SPI 224 IRQ_TYPE_LEVEL_HIGH>;
                clocks = <&bpmp TEGRA186_CLK_EMC>;
                clock-names = "emc";

                nvidia,bpmp = <&bpmp>;
            };
        };
    };

    bpmp: bpmp {
        compatible = "nvidia,tegra186-bpmp";
        #clock-cells = <1>;
    };