On Mon, Jun 26, 2023 at 01:37:16PM +0200, Rafał Miłecki wrote:
> From: Rafał Miłecki <rafal@xxxxxxxxxx>
>
> A lot of home routers have NVMEM fixed cells containing MAC address that
> need some further processing. In ~99% cases MAC needs to be:
> 1. Optionally parsed from ASCII format
> 2. Increased by a vendor-picked value
>
> There was already an attempt to design a binding for that at NVMEM
> device level in the past. It wasn't accepted though as it didn't really
> fit NVMEM device layer.
>
> The introduction of NVMEM fixed-cells layout seems to be an opportunity
> to provide a relevant binding in a clean way.
>
> This commit adds a *generic* compatible string: "mac-base". As always it
> needs to be carefully reviewed.
>
> OpenWrt project currently supports ~300 home routers that have NVMEM
> cell with binary-stored base MAC.T hose devices are manufactured by
> multiple vendors. There are TP-Link devices (76 of them), Netgear (19),
> D-Link (11), OpenMesh (9), EnGenius (8), GL.iNet (8), ZTE (7),
> Xiaomi (5), Ubiquiti (6) and more. Those devices don't share an
> architecture or SoC.
>
> Another 200 devices have base MAC stored in an ASCII format (not all
> those devices have been converted to DT though).
>
> It would be impractical to provide unique "compatible" strings for NVMEM
> layouts of all those devices. It seems like a valid case for allowing a
> generic binding instead. Even if this binding will not be sufficient for
> some further devices it seems to be useful enough as it is.
>
> Signed-off-by: Rafał Miłecki <rafal@xxxxxxxxxx>
> ---
> V2: Drop "mac-ascii" as length can be checked instead
> Fix "allOf" by adding required: [ compatible ]
> ---
> .../bindings/nvmem/layouts/fixed-cell.yaml | 26 +++++++++++++++++++
> .../bindings/nvmem/layouts/fixed-layout.yaml | 12 +++++++++
> .../devicetree/bindings/nvmem/nvmem.yaml | 5 +++-
> 3 files changed, 42 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/devicetree/bindings/nvmem/layouts/fixed-cell.yaml b/Documentation/devicetree/bindings/nvmem/layouts/fixed-cell.yaml
> index e698098450e1..036a9ed88893 100644
> --- a/Documentation/devicetree/bindings/nvmem/layouts/fixed-cell.yaml
> +++ b/Documentation/devicetree/bindings/nvmem/layouts/fixed-cell.yaml
> @@ -11,6 +11,15 @@ maintainers:
> - Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
>
> properties:
> + compatible:
> + oneOf:
> + - const: mac-base
> + description: >
> + Cell with base MAC address to be used for calculating extra relative
> + addresses.
> + It can be stored in a plain binary format (cell length 12) or as an
Don't you mean a length of 6?
> + ASCII text like "00:11:22:33:44:55" (cell length 17).
> +
> reg:
> maxItems: 1
>
> @@ -25,6 +34,23 @@ properties:
> description:
> Size in bit within the address range specified by reg.
>
> +allOf:
> + - if:
> + required: [ compatible ]
> + then:
> + if:
> + properties:
> + compatible:
> + contains:
> + const: mac-base
> + then:
> + properties:
> + "#nvmem-cell-cells":
> + description: The first argument is a MAC address offset.
> + const: 1
> + required:
> + - "#nvmem-cell-cells"
> +
> required:
> - reg
>
> diff --git a/Documentation/devicetree/bindings/nvmem/layouts/fixed-layout.yaml b/Documentation/devicetree/bindings/nvmem/layouts/fixed-layout.yaml
> index c271537d0714..b3a09e8864f1 100644
> --- a/Documentation/devicetree/bindings/nvmem/layouts/fixed-layout.yaml
> +++ b/Documentation/devicetree/bindings/nvmem/layouts/fixed-layout.yaml
> @@ -44,6 +44,18 @@ examples:
> #address-cells = <1>;
> #size-cells = <1>;
>
> + mac@100 {
> + compatible = "mac-base";
> + reg = <0x100 0xc>;
> + #nvmem-cell-cells = <1>;
> + };
> +
> + mac@110 {
> + compatible = "mac-base";
> + reg = <0x110 0x11>;
> + #nvmem-cell-cells = <1>;
> + };
> +
> calibration@4000 {
> reg = <0x4000 0x100>;
> };
> diff --git a/Documentation/devicetree/bindings/nvmem/nvmem.yaml b/Documentation/devicetree/bindings/nvmem/nvmem.yaml
> index 980244100690..9f921d940142 100644
> --- a/Documentation/devicetree/bindings/nvmem/nvmem.yaml
> +++ b/Documentation/devicetree/bindings/nvmem/nvmem.yaml
> @@ -49,7 +49,10 @@ properties:
> patternProperties:
> "@[0-9a-f]+(,[0-7])?$":
> type: object
> - $ref: layouts/fixed-cell.yaml
> + allOf:
> + - $ref: layouts/fixed-cell.yaml
> + - properties:
> + compatible: false
> deprecated: true
>
> additionalProperties: true
> --
> 2.35.3
>
