# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/memory-controllers/nvidia,tegra20-emc.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#

title: NVIDIA Tegra20 SoC External Memory Controller

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

description: |
  The External Memory Controller (EMC) interfaces with the off-chip SDRAM to
  service the request stream sent from Memory Controller. The EMC also has
  various performance-affecting settings beyond the obvious SDRAM configuration
  parameters and initialization settings. Tegra20 EMC supports multiple JEDEC
  standard protocols: DDR1, LPDDR2 and DDR2.

properties:
  compatible:
    const: nvidia,tegra20-emc

  reg:
    maxItems: 1

  clocks:
    maxItems: 1

  interrupts:
    maxItems: 1
 
  "#address-cells":
    const: 1
 
  "#size-cells":
    const: 0
 
  "#interconnect-cells":
    const: 0

  nvidia,memory-controller:
    $ref: /schemas/types.yaml#/definitions/phandle
    description:
      Phandle of the Memory Controller node.

  power-domains:
    maxItems: 1
    description:
      Phandle of the SoC "core" power domain.

  operating-points-v2:
    description:
      Should contain freqs and voltages and opp-supported-hw property, which
      is a bitfield indicating SoC process ID mask.

  nvidia,use-ram-code:
    type: boolean
    description:
      If present, the emc-tables@ sub-nodes will be addressed.

$defs:
  emc-table:
    type: object
    properties:
      compatible:
        const: nvidia,tegra20-emc-table

      clock-frequency:
        description:
          Memory clock rate in kHz.
        minimum: 1000
        maximum: 900000

      reg:
        maxItems: 1
        description:
          Either an opaque enumerator to tell different tables apart, or
          the valid frequency for which the table should be used (in kHz).

      nvidia,emc-registers:
        description:
          EMC timing characterization data. These are the registers
          (see section "15.4.1 EMC Registers" in the TRM) whose values
          need to be specified, according to the board documentation.
        $ref: /schemas/types.yaml#/definitions/uint32-array
        items:
          - description: EMC_RC
          - description: EMC_RFC
          - description: EMC_RAS
          - description: EMC_RP
          - description: EMC_R2W
          - description: EMC_W2R
          - description: EMC_R2P
          - description: EMC_W2P
          - description: EMC_RD_RCD
          - description: EMC_WR_RCD
          - description: EMC_RRD
          - description: EMC_REXT
          - description: EMC_WDV
          - description: EMC_QUSE
          - description: EMC_QRST
          - description: EMC_QSAFE
          - description: EMC_RDV
          - description: EMC_REFRESH
          - description: EMC_BURST_REFRESH_NUM
          - description: EMC_PDEX2WR
          - description: EMC_PDEX2RD
          - description: EMC_PCHG2PDEN
          - description: EMC_ACT2PDEN
          - description: EMC_AR2PDEN
          - description: EMC_RW2PDEN
          - description: EMC_TXSR
          - description: EMC_TCKE
          - description: EMC_TFAW
          - description: EMC_TRPAB
          - description: EMC_TCLKSTABLE
          - description: EMC_TCLKSTOP
          - description: EMC_TREFBW
          - description: EMC_QUSE_EXTRA
          - description: EMC_FBIO_CFG6
          - description: EMC_ODT_WRITE
          - description: EMC_ODT_READ
          - description: EMC_FBIO_CFG5
          - description: EMC_CFG_DIG_DLL
          - description: EMC_DLL_XFORM_DQS
          - description: EMC_DLL_XFORM_QUSE
          - description: EMC_ZCAL_REF_CNT
          - description: EMC_ZCAL_WAIT_CNT
          - description: EMC_AUTO_CAL_INTERVAL
          - description: EMC_CFG_CLKTRIM_0
          - description: EMC_CFG_CLKTRIM_1
          - description: EMC_CFG_CLKTRIM_2

    required:
      - clock-frequency
      - compatible
      - reg
      - nvidia,emc-registers

    additionalProperties: false

patternProperties:
  "^emc-table@[0-9]+$":
    $ref: "#/$defs/emc-table"
 
  "^emc-tables@[a-z0-9-]+$":
    type: object
    properties:
      reg:
        maxItems: 1
        description:
          An opaque enumerator to tell different tables apart.

      nvidia,ram-code:
        $ref: /schemas/types.yaml#/definitions/uint32
        description:
          Value of RAM_CODE this timing set is used for.
 
      "#address-cells":
        const: 1
 
      "#size-cells":
        const: 0

      lpddr2:
        $ref: ddr/jedec,lpddr2.yaml#
        type: object

    patternProperties:
      "^emc-table@[0-9]+$":
        $ref: "#/$defs/emc-table"

    oneOf:
      - required:
          - nvidia,ram-code

      - required:
          - lpddr2

    additionalProperties: false

required:
  - compatible
  - reg
  - interrupts
  - clocks
  - nvidia,memory-controller
  - "#interconnect-cells"
  - operating-points-v2

additionalProperties: false

examples:
  - |
    external-memory-controller@7000f400 {
        compatible = "nvidia,tegra20-emc";
        reg = <0x7000f400 0x400>;
        interrupts = <0 78 4>;
        clocks = <&clock_controller 57>;
 
        nvidia,memory-controller = <&mc>;
        operating-points-v2 = <&dvfs_opp_table>;
        power-domains = <&domain>;
 
        #interconnect-cells = <0>;
        #address-cells = <1>;
        #size-cells = <0>;
 
        nvidia,use-ram-code;
 
        emc-tables@0 {
            nvidia,ram-code = <0>;
            reg = <0>;
 
            #address-cells = <1>;
            #size-cells = <0>;
 
            emc-table@333000 {
                reg = <333000>;
                compatible = "nvidia,tegra20-emc-table";
                clock-frequency = <333000>;
                nvidia,emc-registers = <0x00000018 0x00000033
                        0x00000012 0x00000004 0x00000004 0x00000005
                        0x00000003 0x0000000c 0x00000006 0x00000006
                        0x00000003 0x00000001 0x00000004 0x00000005
                        0x00000004 0x00000009 0x0000000d 0x00000bff
                        0x00000000 0x00000003 0x00000003 0x00000006
                        0x00000006 0x00000001 0x00000011 0x000000c8
                        0x00000003 0x0000000e 0x00000007 0x00000008
                        0x00000002 0x00000000 0x00000000 0x00000002
                        0x00000000 0x00000000 0x00000083 0xf0440303
                        0x007fe010 0x00001414 0x00000000 0x00000000
                        0x00000000 0x00000000 0x00000000 0x00000000>;
            };
        };
 
        emc-tables@1 {
            reg = <1>;
 
            lpddr2 {
                compatible = "elpida,B8132B2PB-6D-F", "jedec,lpddr2-s4";
                revision-id1 = <1>;
                density = <2048>;
                io-width = <16>;
            };
        };
    };