[1/4,v2] dt-bindings: memory: Factor out common properties of LPDDR bindings

The bindings for different LPDDR versions mostly use the same kinds of
properties, so in order to reduce duplication when we're adding support
for more versions, this patch creates a new lpddr-props subschema that
can be referenced by the others to define these common parts. (This will
consider a few smaller I/O width and density numbers "legal" for LPDDR3
that are usually not used there, but this should be harmless.)

Signed-off-by: Julius Werner <jwerner@chromium.org>
---
 .../ddr/jedec,lpddr-props.yaml                | 52 +++++++++++++++++++
 .../memory-controllers/ddr/jedec,lpddr2.yaml  | 40 ++------------
 .../memory-controllers/ddr/jedec,lpddr3.yaml  | 32 ++----------
 3 files changed, 60 insertions(+), 64 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr-props.yaml

Changelog:

- v2:
  - removed minItems
  - reordered io-width enum from lowest to highest
  - moved `$ref` below `mainainers`
  - removed part about undeprecating manufacturer-id

On 08/09/2022 01:29, Julius Werner wrote:
> This patch adds bindings for LPDDR4 and LPDDR5 memory analogous to the
> existing bindings for LPDDR2 and LPDDR3. For now, the new types are only
> needed for topology description, so other properties like timing
> parameters are omitted. They can be added later if needed.
> 
> Signed-off-by: Julius Werner <jwerner@chromium.org>
> ---
>  .../ddr/jedec,lpddr-props.yaml                |  4 ++
>  .../memory-controllers/ddr/jedec,lpddr4.yaml  | 36 ++++++++++++++
>  .../memory-controllers/ddr/jedec,lpddr5.yaml  | 47 +++++++++++++++++++
>  3 files changed, 87 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr4.yaml
>  create mode 100644 Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr5.yaml
> 
> Changelog:
> 
> - v2
>   - removed minItems
>   - moved `$ref` below `maintainers`
>   - renamed example node from `lpddr4` to `lpddr`
> 
> diff --git a/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr-props.yaml b/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr-props.yaml
> index 4114cfa8de67f1..92ef660888f318 100644
> --- a/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr-props.yaml
> +++ b/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr-props.yaml
> @@ -45,9 +45,13 @@ properties:
>        - 512
>        - 1024
>        - 2048
> +      - 3072
>        - 4096
> +      - 6144
>        - 8192
> +      - 12288
>        - 16384
> +      - 24576
>        - 32768
>  
>    io-width:
> diff --git a/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr4.yaml b/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr4.yaml
> new file mode 100644
> index 00000000000000..0b2394c032797f
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr4.yaml
> @@ -0,0 +1,36 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/memory-controllers/ddr/jedec,lpddr4.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: LPDDR4 SDRAM compliant to JEDEC JESD209-4
> +
> +maintainers:
> +  - Krzysztof Kozlowski <krzk@kernel.org>
> +
> +allOf:
> +  - $ref: "jedec,lpddr-props.yaml#"

No need for quotes.

> +
> +properties:
> +  compatible:
> +    items:
> +      - pattern: "^lpddr4-[0-9a-f]{2},[0-9a-f]{4}$"
> +      - const: jedec,lpddr4
> +
> +required:
> +  - compatible
> +  - density
> +  - io-width
> +
> +unevaluatedProperties: false
> +
> +examples:
> +  - |
> +    lpddr {
> +        compatible = "lpddr4-ff,0100", "jedec,lpddr4";
> +        density = <8192>;
> +        io-width = <16>;
> +        manufacturer-id = <255>;
> +        revision-id = <1 0>;
> +    };
> diff --git a/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr5.yaml b/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr5.yaml
> new file mode 100644
> index 00000000000000..d86e1e30380e47
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr5.yaml
> @@ -0,0 +1,47 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/memory-controllers/ddr/jedec,lpddr5.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: LPDDR5 SDRAM compliant to JEDEC JESD209-5
> +
> +maintainers:
> +  - Krzysztof Kozlowski <krzk@kernel.org>
> +
> +allOf:
> +  - $ref: "jedec,lpddr-props.yaml#"

No need for quotes.

> +
> +properties:
> +  compatible:
> +    items:
> +      - pattern: "^lpddr5-[0-9a-f]{2},[0-9a-f]{4}$"
> +      - const: jedec,lpddr5
> +
> +  serial-id:
> +    $ref: /schemas/types.yaml#/definitions/uint32-array
> +    description:
> +      Serial IDs read from Mode Registers 47 through 54. One byte per uint32
> +      cell (i.e. <MR47 MR48 MR49 MR50 MR51 MR52 MR53 MR54>).
> +    maxItems: 8
> +    items:
> +      minimum: 0
> +      maximum: 255
> +
> +required:
> +  - compatible
> +  - density
> +  - io-width
> +
> +unevaluatedProperties: false
> +
> +examples:
> +  - |
> +    lpddr {
> +        compatible = "lpddr5-01,0200", "jedec,lpddr5";
> +        density = <8192>;
> +        io-width = <8>;
> +        manufacturer-id = <1>;

Does not look like you tested the bindings. Please run `make
dt_binding_check` (see
Documentation/devicetree/bindings/writing-schema.rst for instructions).

> +        revision-id = <2 0>;
> +        serial-id = <3 1 0 0 0 0 0 0>;
> +    };


Best regards,
Krzysztof

On Wed, 07 Sep 2022 16:29:11 -0700, Julius Werner wrote:
> The bindings for different LPDDR versions mostly use the same kinds of
> properties, so in order to reduce duplication when we're adding support
> for more versions, this patch creates a new lpddr-props subschema that
> can be referenced by the others to define these common parts. (This will
> consider a few smaller I/O width and density numbers "legal" for LPDDR3
> that are usually not used there, but this should be harmless.)
> 
> Signed-off-by: Julius Werner <jwerner@chromium.org>
> ---
>  .../ddr/jedec,lpddr-props.yaml                | 52 +++++++++++++++++++
>  .../memory-controllers/ddr/jedec,lpddr2.yaml  | 40 ++------------
>  .../memory-controllers/ddr/jedec,lpddr3.yaml  | 32 ++----------
>  3 files changed, 60 insertions(+), 64 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr-props.yaml
> 
> Changelog:
> 
> - v2:
>   - removed minItems
>   - reordered io-width enum from lowest to highest
>   - moved `$ref` below `mainainers`
>   - removed part about undeprecating manufacturer-id
> 

Acked-by: Rob Herring <robh@kernel.org>

On Wed, 07 Sep 2022 16:29:12 -0700, Julius Werner wrote:
> This patch allows a new kind of compatible string for LPDDR parts in the
> device tree bindings, in addition to the existing hardcoded
> <vendor>,<part-number> strings. The new format contains manufacturer and
> part (revision) information in numerical form, such as lpddr3-ff,0201
> for an LPDDR3 part with manufacturer ID ff and revision ID 0201. This
> helps cases where LPDDR parts are probed at runtime by boot firmware and
> cannot be matched to hardcoded part numbers, such as the firmware on the
> qcom/sc7280-herobrine boards does (which supports 4 different memory
> configurations at the moment, and more are expected to be added later at
> a point where the boot firmware can no longer be updated to specifically
> accomodate them).
> 
> Signed-off-by: Julius Werner <jwerner@chromium.org>
> ---
>  .../memory-controllers/ddr/jedec,lpddr-props.yaml    | 10 ++++++++++
>  .../memory-controllers/ddr/jedec,lpddr2.yaml         |  8 +++++---
>  .../memory-controllers/ddr/jedec,lpddr3.yaml         | 12 ++++++++----
>  3 files changed, 23 insertions(+), 7 deletions(-)
> 
> Changelog:
> 
> - v2
>   - Updated commit message to describe intended use case as an example
> 

Acked-by: Rob Herring <robh@kernel.org>