Re: [PATCH V1 1/4] bindings: nvmem: introduce "reverse-data" property

From: Rob Herring
Date: Tue Aug 17 2021 - 15:58:05 EST


On Wed, Aug 11, 2021 at 11:16:49AM +0100, Srinivas Kandagatla wrote:
>
>
> On 10/08/2021 08:35, Joakim Zhang wrote:
> > Introduce "reverse-data" property for nvmem provider to reverse buffer.
> >
> > Signed-off-by: Joakim Zhang <qiangqing.zhang@xxxxxxx>
> > ---
> > Documentation/devicetree/bindings/nvmem/nvmem.yaml | 5 +++++
> > 1 file changed, 5 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/nvmem/nvmem.yaml b/Documentation/devicetree/bindings/nvmem/nvmem.yaml
> > index b8dc3d2b6e92..bc745083fc64 100644
> > --- a/Documentation/devicetree/bindings/nvmem/nvmem.yaml
> > +++ b/Documentation/devicetree/bindings/nvmem/nvmem.yaml
> > @@ -61,6 +61,11 @@ patternProperties:
> > description:
> > Size in bit within the address range specified by reg.
> > + reverse-data:
> > + $ref: /schemas/types.yaml#/definitions/flag
> > + description:
> > + Reverse the data that read from the storage device.
> > +
>
> This new property is only going to solve one of the reverse order issue
> here.
> If I remember correctly we have mac-address stored in various formats ex:
> from old thread I can see
>
> Type 1: Octets in ASCII without delimiters. (Swapped/non-Swapped)
> Type 2: Octets in ASCII with delimiters like (":", ",", ".", "-"... so on)
> (Swapped/non-Swapped)
> Type 3: Is the one which stores mac address in Type1/2 but this has to be
> incremented to be used on other instances of eth.
> Type 4: Octets as bytes/u8, swapped/non-swapped
>
> I think its right time to consider adding compatibles to nvmem-cells to be
> able to specify encoding information and handle post processing.

Yes. Trying to handle this with never ending new properties will end up
with a mess. At some point, you just need code to parse the data.

Rob