Re: [PATCH V5 1/3] dt-bindings: nvmem: layouts: add fixed-layout

From: Rob Herring
Date: Mon Mar 27 2023 - 09:51:38 EST


On Tue, Mar 21, 2023 at 11:24:16AM +0100, Rafał Miłecki wrote:
> From: Rafał Miłecki <rafal@xxxxxxxxxx>
>
> With the introduction of NVMEM layouts, new NVMEM content structures
> should be defined as such. We should also try to convert / migrate
> existing NVMEM content bindings to layouts.
>
> This commit handles fixed NVMEM cells. So far they had to be defined
> directly - as device subnodes. With this change it's allowed to put them
> in the DT node named "nvmem-layout".
>
> Having NVMEM cells in separated node is preferred as it draws a nice
> line between NVMEM device and its content. It results in cleaner
> bindings.
>
> FWIW a very similar situation has happened to MTD devices and their
> partitions: see commit 5d96ea42eb63 ("dt-bindings: mtd: Clarify all
> partition subnodes").
>
> Signed-off-by: Rafał Miłecki <rafal@xxxxxxxxxx>
> ---
> .../bindings/nvmem/layouts/fixed-cell.yaml | 31 ++++++++++++
> .../bindings/nvmem/layouts/fixed-layout.yaml | 49 +++++++++++++++++++
> .../bindings/nvmem/layouts/nvmem-layout.yaml | 5 +-
> .../devicetree/bindings/nvmem/nvmem.yaml | 19 +------
> 4 files changed, 83 insertions(+), 21 deletions(-)
> create mode 100644 Documentation/devicetree/bindings/nvmem/layouts/fixed-cell.yaml
> create mode 100644 Documentation/devicetree/bindings/nvmem/layouts/fixed-layout.yaml
>
> diff --git a/Documentation/devicetree/bindings/nvmem/layouts/fixed-cell.yaml b/Documentation/devicetree/bindings/nvmem/layouts/fixed-cell.yaml
> new file mode 100644
> index 000000000000..e698098450e1
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/nvmem/layouts/fixed-cell.yaml
> @@ -0,0 +1,31 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/nvmem/layouts/fixed-cell.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Fixed offset & size NVMEM cell
> +
> +maintainers:
> + - Rafał Miłecki <rafal@xxxxxxxxxx>
> + - Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
> +
> +properties:
> + reg:
> + maxItems: 1
> +
> + bits:
> + $ref: /schemas/types.yaml#/definitions/uint32-array
> + items:
> + - minimum: 0
> + maximum: 7
> + description:
> + Offset in bit within the address range specified by reg.
> + - minimum: 1
> + description:
> + Size in bit within the address range specified by reg.
> +
> +required:
> + - reg
> +
> +additionalProperties: true
> diff --git a/Documentation/devicetree/bindings/nvmem/layouts/fixed-layout.yaml b/Documentation/devicetree/bindings/nvmem/layouts/fixed-layout.yaml
> new file mode 100644
> index 000000000000..f7496ba28f33
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/nvmem/layouts/fixed-layout.yaml
> @@ -0,0 +1,49 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/nvmem/layouts/fixed-layout.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: NVMEM layout for fixed NVMEM cells
> +
> +description:
> + Many NVMEM devices have hardcoded cells layout (offset and size of defined
> + NVMEM content doesn't change).
> +
> + This binding allows defining such NVMEM layout with its cells. It can be used
> + on top of any NVMEM device.
> +
> +maintainers:
> + - Rafał Miłecki <rafal@xxxxxxxxxx>
> +
> +properties:
> + compatible:
> + const: fixed-layout
> +
> + "#address-cells":
> + const: 1
> +
> + "#size-cells":
> + const: 1
> +
> +patternProperties:
> + "@[a-f0-9]+$":
> + type: object
> + $ref: fixed-cell.yaml

This $ref allows additional properties, so here you need
'unevaluatedProperties: false'. Or restrict fixed-cell.yaml.

> +
> +required:
> + - compatible
> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + nvmem-layout {
> + compatible = "fixed-layout";
> + #address-cells = <1>;
> + #size-cells = <1>;
> +
> + calibration@4000 {
> + reg = <0x4000 0x100>;
> + };
> + };
> diff --git a/Documentation/devicetree/bindings/nvmem/layouts/nvmem-layout.yaml b/Documentation/devicetree/bindings/nvmem/layouts/nvmem-layout.yaml
> index 8512ee538c4c..3b40f7880774 100644
> --- a/Documentation/devicetree/bindings/nvmem/layouts/nvmem-layout.yaml
> +++ b/Documentation/devicetree/bindings/nvmem/layouts/nvmem-layout.yaml
> @@ -18,16 +18,13 @@ description: |
> perform their parsing. The nvmem-layout container is here to describe these.
>
> oneOf:
> + - $ref: fixed-layout.yaml
> - $ref: kontron,sl28-vpd.yaml
> - $ref: onie,tlv-layout.yaml
>
> properties:
> compatible: true
>
> - '#address-cells': false
> -
> - '#size-cells': false
> -
> required:
> - compatible
>
> diff --git a/Documentation/devicetree/bindings/nvmem/nvmem.yaml b/Documentation/devicetree/bindings/nvmem/nvmem.yaml
> index 75bb93dda9df..b79f1bb795fb 100644
> --- a/Documentation/devicetree/bindings/nvmem/nvmem.yaml
> +++ b/Documentation/devicetree/bindings/nvmem/nvmem.yaml
> @@ -49,23 +49,8 @@ properties:
> patternProperties:
> "@[0-9a-f]+(,[0-7])?$":
> type: object
> -
> - properties:
> - reg:
> - maxItems: 1
> - description:
> - Offset and size in bytes within the storage device.
> -
> - bits:
> - $ref: /schemas/types.yaml#/definitions/uint32-array
> - items:
> - - minimum: 0
> - maximum: 7
> - description:
> - Offset in bit within the address range specified by reg.
> - - minimum: 1
> - description:
> - Size in bit within the address range specified by reg.
> + $ref: layouts/fixed-cell.yaml
> + deprecated: true
>
> additionalProperties: true
>
> --
> 2.34.1
>