Commit b5c1a217 authored by Clément Le Goffic's avatar Clément Le Goffic Committed by Krzysztof Kozlowski
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dt-bindings: memory: introduce DDR4 



Introduce JEDEC compliant DDR bindings, that use new memory-props binding.

The DDR4 compatible can be made of explicit vendor names and part
numbers or be of the form "ddrX-YYYY,AAAA...-ZZ" when associated with an
SPD, where (according to JEDEC SPD4.1.2.L-6):
- YYYY is the manufacturer ID
- AAAA... is the part number
- ZZ is the revision ID

The former form is useful when the SDRAM vendor and part number are
known, for example, when memory is soldered on the board.
The latter form is useful when SDRAM nodes are created at runtime by
boot firmware that doesn't have access to static part number information.

Signed-off-by: default avatarClément Le Goffic <clement.legoffic@foss.st.com>
Signed-off-by: default avatarClément Le Goffic <legoffic.clement@gmail.com>
Reviewed-by: default avatarRob Herring (Arm) <robh@kernel.org>
Link: https://patch.msgid.link/20251118-b4-ddr-bindings-v9-2-a033ac5144da@gmail.com


Signed-off-by: default avatarKrzysztof Kozlowski <krzk@kernel.org>
parent dffaa1be

Documentation/devicetree/bindings/memory-controllers/ddr/jedec,ddr4.yaml

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# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)

%YAML 1.2

---

$id: http://devicetree.org/schemas/memory-controllers/ddr/jedec,ddr4.yaml#

$schema: http://devicetree.org/meta-schemas/core.yaml#



title: DDR4 SDRAM compliant to JEDEC JESD79-4D



maintainers:

  - Krzysztof Kozlowski <krzk@kernel.org>



allOf:

  - $ref: jedec,sdram-props.yaml#



properties:

  compatible:

    items:

      - pattern: "^ddr4-[0-9a-f]{4},[a-z]{1,20}-[0-9a-f]{2}$"

      - const: jedec,ddr4



required:

  - compatible

  - density

  - io-width



unevaluatedProperties: false



examples:

  - |

    ddr {

        compatible = "ddr4-00ff,azaz-ff", "jedec,ddr4";

        density = <8192>;

        io-width = <8>;

    };