Re: [PATCH v4 2/3] dt-bindings: mtd: binman-partition: Add binman compatibles

[Rob Herring <robh@kernel.org>]

On Mon, Oct 09, 2023 at 04:04:14PM -0600, Simon Glass wrote:
> Add two compatible for binman entries, as a starting point for the
> schema.
> 
> Note that, after discussion on v2, we decided to keep the existing
> meaning of label so as not to require changes to existing userspace
> software when moving to use binman nodes to specify the firmware
> layout.
> 
> Signed-off-by: Simon Glass <sjg@chromium.org>
> ---
> 
> Changes in v4:
> - Correct selection of multiple compatible strings
> 
> Changes in v3:
> - Drop fixed-partitions from the example
> - Use compatible instead of label
> 
> Changes in v2:
> - Use plain partition@xxx for the node name
> 
>  .../mtd/partitions/binman-partition.yaml      | 49 +++++++++++++++++++
>  1 file changed, 49 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/mtd/partitions/binman-partition.yaml
> 
> diff --git a/Documentation/devicetree/bindings/mtd/partitions/binman-partition.yaml b/Documentation/devicetree/bindings/mtd/partitions/binman-partition.yaml
> new file mode 100644
> index 000000000000..35a320359ec1
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mtd/partitions/binman-partition.yaml
> @@ -0,0 +1,49 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +# Copyright 2023 Google LLC
> +
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/mtd/partitions/binman-partition.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Binman partition
> +
> +maintainers:
> +  - Simon Glass <sjg@chromium.org>
> +
> +select: false

So this schema is never used. 'select: false' is only useful if 
something else if referencing the schema.

> +
> +description: |
> +  This corresponds to a binman 'entry'. It is a single partition which holds
> +  data of a defined type.
> +
> +allOf:
> +  - $ref: /schemas/mtd/partitions/partition.yaml#
> +
> +properties:
> +  compatible:
> +    oneOf:
> +      - const: binman,entry     # generic binman entry

'binman' is not a vendor. You could add it if you think that's useful. 
Probably not with only 1 case...

> +      - items:
> +          - const: u-boot       # u-boot.bin from U-Boot project
> +          - const: atf-bl31     # bl31.bin or bl31.elf from TF-A project

Probably should use the new 'tfa' rather than old 'atf'. Is this the 
only binary for TFA? The naming seems inconsistent in that every image 
goes in (or can go in) a bl?? section. Why does TFA have it but u-boot 
doesn't? Perhaps BL?? is orthogonal to defining what is in each 
partition. Perhaps someone more familar with all this than I am can 
comment.

Once you actually test this, you'll find you are specifying:

compatible = "u-boot", "atf-bl31";


> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    partitions {
> +        compatible = "binman";
> +        #address-cells = <1>;
> +        #size-cells = <1>;
> +
> +        partition@100000 {
> +            compatible = "u-boot";
> +            reg = <0x100000 0xf00000>;
> +        };
> +
> +        partition@200000 {
> +            compatible = "atf-bl31";
> +            reg = <0x200000 0x100000>;
> +        };
> +    };
> -- 
> 2.42.0.609.gbb76f46606-goog
>