Re: [PATCH v1 08/14] dt-bindings: mtd: relax the nvmem compatible string

[Michael Walle]

Am 2022-08-31 23:48, schrieb Rob Herring:
> On Thu, Aug 25, 2022 at 11:44:17PM +0200, Michael Walle wrote:
> > The "user-otp" and "factory-otp" compatible string just depicts a
> > generic NVMEM device. But an actual device tree node might as well
> > contain a more specific compatible string. Make it possible to add
> > more specific binding elsewere and just match part of the compatibles
> > here.
> >
> > Signed-off-by: Michael Walle <michael@xxxxxxxx>
> > ---
> >  Documentation/devicetree/bindings/mtd/mtd.yaml | 7 ++++---
> >  1 file changed, 4 insertions(+), 3 deletions(-)
>
> In hindsight it looks like we are mixing 2 different purposes of 'which
> instance is this' and 'what is this'. 'compatible' is supposed to be 
> the
> latter.
>
> Maybe there's a better way to handle user/factory? There's a similar
> need with partitions for A/B or factory/update.

I'm not sure I understand what you mean. It has nothing to with
user and factory provisionings.

SPI flashes have a user programmable and a factory programmable
area, some have just one of them. Whereas with A/B you (as in the
user or the board manufacturer) defines an area within a memory device
to be either slot A or slot B. But here the flash dictates what's
factory and what's user storage. It's in the datasheet.

HTH
-michael