On Wed, Jan 26, 2022 at 08:07:45AM +0100, Rafał Miłecki wrote: > From: Rafał Miłecki <rafal@xxxxxxxxxx> > > This adds support for describing details of NVMEM cell containing MAC > address. Those are often device specific and could be nicely stored in > DT. > > Initial documentation includes support for describing: > 1. Cell data format (e.g. Broadcom's NVRAM uses ASCII to store MAC) > 2. Reversed bytes flash (required for i.MX6/i.MX7 OCOTP support) > 3. Source for multiple addresses (very common in home routers) > > Signed-off-by: Rafał Miłecki <rafal@xxxxxxxxxx> > --- > .../bindings/nvmem/cells/mac-address.yaml | 94 +++++++++++++++++++ > 1 file changed, 94 insertions(+) > create mode 100644 Documentation/devicetree/bindings/nvmem/cells/mac-address.yaml > > diff --git a/Documentation/devicetree/bindings/nvmem/cells/mac-address.yaml b/Documentation/devicetree/bindings/nvmem/cells/mac-address.yaml > new file mode 100644 > index 000000000000..f8d19e87cdf0 > --- /dev/null > +++ b/Documentation/devicetree/bindings/nvmem/cells/mac-address.yaml > @@ -0,0 +1,94 @@ > +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause > +%YAML 1.2 > +--- > +$id: http://devicetree.org/schemas/nvmem/cells/mac-address.yaml# > +$schema: http://devicetree.org/meta-schemas/core.yaml# > + > +title: NVMEM cell containing a MAC address > + > +maintainers: > + - Rafał Miłecki <rafal@xxxxxxxxxx> > + > +properties: > + compatible: > + const: mac-address > + > + format: > + description: | > + Some NVMEM cells contain MAC in a non-binary format. > + > + ASCII should be specified if MAC is string formatted like: > + - "01:23:45:67:89:AB" (30 31 3a 32 33 3a 34 35 3a 36 37 3a 38 39 3a 41 42) > + - "01-23-45-67-89-AB" > + - "0123456789AB" > + enum: > + - ascii > + > + reversed-bytes: > + type: boolean > + description: | > + MAC is stored in reversed bytes order. Example: > + Stored value: AB 89 67 45 23 01 > + Actual MAC: 01 23 45 67 89 AB > + > + base-address: > + type: boolean > + description: | > + Marks NVMEM cell as provider of multiple addresses that are relative to > + the one actually stored physically. Respective addresses can be requested > + by specifying cell index of NVMEM cell. While a base address is common, aren't there different ways the base is modified. The problem with these properties is every new variation results in a new property and the end result is something not well designed. A unique compatible string, "#nvmem-cell-cells" and code to interpret the data is more flexible. For something like this to fly, I need some level of confidence this is enough for everyone for some time (IOW, find all the previous attempts and get those people's buy-in). You have found at least 3 cases, but I seem to recall more. Rob
