Re: [PATCH v8 1/9] dt-bindings: mmc: Document fixed-layout NVMEM provider support

[Loic Poulain]

Hi Ulf,

On Thu, Jul 16, 2026 at 3:16 PM Ulf Hansson
<ulf.hansson@xxxxxxxxxxxxxxxx> wrote:
>
> - trimmed the cc-list
>
> On Fri, Jul 3, 2026 at 3:45 PM Loic Poulain
> <loic.poulain@xxxxxxxxxxxxxxxx> wrote:
> >
> > Allow an eMMC hardware partition node to describe an NVMEM layout so the
> > partition can be exposed as an NVMEM provider. This lets a partition
> > (e.g. an eMMC boot partition) store device-specific information such as a
> > WiFi MAC address or a Bluetooth BD address and reference it through NVMEM
> > cells.
> >
> > Accept "fixed-layout" as the partition node compatible, in addition to
> > "fixed-partitions", so the layout can be described directly on the
> > partition node.
> >
> > Signed-off-by: Loic Poulain <loic.poulain@xxxxxxxxxxxxxxxx>
>
> I think it would be nice to have some version history here as well,
> for next time. I noticed that v6 was reviewed and ready to go, but
> then something changed in v7 as those tags were dropped.

Indeed, the changes in v7 significantly reworked the DTS and binding
structure, so I did not carry over the tags.

This was called out in the cover letter:
Rework bindings/DTS so that the eMMC boot partition can be expressed
as an nvmem fixed-layout rather than as a child of fixed-partitions.

This change was made following the discussion with Rob:
https://lore.kernel.org/all/CAFEp6-20FXTOKQ6EPuR8OUDkqE4JXcUbXaFy7kRFt4fzszPQCA@xxxxxxxxxxxxxx/

That said, I'll make sure to include the version-to-version context
directly in the commit message and/or when such changes occur.

Regards,
Loic



>
> > ---
> >  .../devicetree/bindings/mmc/mmc-card.yaml          | 23 +++++++++++++++++++++-
> >  1 file changed, 22 insertions(+), 1 deletion(-)
> >
> > diff --git a/Documentation/devicetree/bindings/mmc/mmc-card.yaml b/Documentation/devicetree/bindings/mmc/mmc-card.yaml
> > index a61d6c96df759102f9c1fbfd548b026a77921cae..0422894508478c8d0ca68292b58a5fdbee218358 100644
> > --- a/Documentation/devicetree/bindings/mmc/mmc-card.yaml
> > +++ b/Documentation/devicetree/bindings/mmc/mmc-card.yaml
> > @@ -38,7 +38,9 @@ patternProperties:
> >      properties:
> >        compatible:
> >          contains:
> > -          const: fixed-partitions
> > +          enum:
> > +            - fixed-partitions
> > +            - fixed-layout
> >
> >  required:
> >    - compatible
> > @@ -86,6 +88,25 @@ examples:
> >                      read-only;
> >                  };
> >              };
> > +
> > +            partitions-boot2 {
> > +                compatible = "fixed-layout";
> > +
> > +                #address-cells = <1>;
> > +                #size-cells = <1>;
> > +
> > +                mac-addr@4400 {
> > +                    compatible = "mac-base";
> > +                    reg = <0x4400 0x6>;
> > +                    #nvmem-cell-cells = <1>;
> > +                };
> > +
> > +                bd-addr@5400 {
> > +                    compatible = "mac-base";
> > +                    reg = <0x5400 0x6>;
> > +                    #nvmem-cell-cells = <1>;
> > +                };
> > +            };
> >          };
> >      };
> >
> >
> > --
> > 2.34.1
> >