Re: [PATCH dt-schema.git] schemas: add NVMEM cell with #nvmem-cell-cells

[Rafał Miłecki]

On 21.11.2022 12:25, Krzysztof Kozlowski wrote:
> On 21/11/2022 11:58, Rafał Miłecki wrote:
> > From: Rafał Miłecki <rafal@xxxxxxxxxx>
> >
> > Some NVMEM cells may provide more than 1 value. An example can be base
> > MAC address that is used for calculating multiple MACs (for few
> > different devices). For specifying value to read phandle needs to be
> > used with an argument.
> >
> > Cc: Srinivas Kandagatla" <srinivas.kandagatla@xxxxxxxxxx>
> > Cc: Michael Walle <michael@xxxxxxxx>
> > Signed-off-by: Rafał Miłecki <rafal@xxxxxxxxxx>
> > ---
> > This bit is required for moving forward with the
> > [PATCH v2 00/20] nvmem: core: introduce NVMEM layouts
> > https://lore.kernel.org/linux-arm-kernel/20220901221857.2600340-1-michael@xxxxxxxx/
> >
> > As pointed out by Rob #nvmem-cell-cells should be added to the dt-schema
> > and not a Linux binding:
> > Re: [PATCH v2 15/20] dt-bindings: nvmem: add YAML schema for the sl28 vpd layout
> > https://lore.kernel.org/linux-arm-kernel/20220912192038.GA1661550-robh@xxxxxxxxxx/
> >
> > sl28 is one example that needs #nvmem-cell-cells
> > u-boot,env is another one
> >
> > Please let me know if I got this binding right at all.
> > ---
> >   dtschema/schemas/nvmem/nvmem-cell.yaml | 23 +++++++++++++++++++++++
> >   1 file changed, 23 insertions(+)
> >   create mode 100644 dtschema/schemas/nvmem/nvmem-cell.yaml
> >
> > diff --git a/dtschema/schemas/nvmem/nvmem-cell.yaml b/dtschema/schemas/nvmem/nvmem-cell.yaml
> > new file mode 100644
> > index 0000000..dfa99b8
> > --- /dev/null
> > +++ b/dtschema/schemas/nvmem/nvmem-cell.yaml
> > @@ -0,0 +1,23 @@
> > +# SPDX-License-Identifier: BSD-2-Clause
> > +$id: "http://devicetree.org/schemas/nvmem/nvmem-cell.yaml#";
> > +$schema: "http://devicetree.org/meta-schemas/base.yaml#";
>
> Drop quotes from both.
>
> > +
> > +title: NVMEM Cell Common Properties
> > +description: "Schema for NVMEM cell devicetree bindings"
>
> Drop quotes.
>
> > +maintainers:
> > +  - Rafał Miłecki <rafal@xxxxxxxxxx>
> > +  - Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
> > +
> > +# always select the core schema
> > +select: true
> > +
> > +properties:
> > +  "#nvmem-cell-cells":
> > +    $ref: "/schemas/types.yaml#/definitions/uint32"
>
> Drop quotes.
>
> Rest looks fine to me, except a bit funny cell-cell name, but that's
> just life. :)

Bothers me a bit too, I was even thinking about renaming NVMEM cells to
NVMEM entries but I'm not sure if it's not too late for that.

We already have "nvmem-cells" and "nvmem-cell-names" properties so
adding "entries" not would be probably confusing.


> > +    description: >
> > +      Some NVMEM cells may consist of raw data that requires some extra
> > +      processing. They may provide more than 1 value.
> > +
> > +      Passing extra argument(s) allows selecting data to access.
> > +
> > +additionalProperties: true