Re: [PATCH] ARM: tegra: add "nor-jedec" flash compatible binding

[Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>]

On Fri, May 8, 2015 at 8:43 PM, Brian Norris
<computersforpeace@xxxxxxxxx> wrote:
> On Fri, May 08, 2015 at 10:00:12AM -0600, Stephen Warren wrote:
>> On 05/08/2015 12:21 AM, Rafał Miłecki wrote:
>> >Starting with commits
>> >8ff16cf ("Documentation: devicetree: m25p80: add "nor-jedec" binding")
>> >1103b85 ("mtd: m25p80: bind to "nor-jedec" ID, for auto-detection")
>> >we have "nor-jedec" binding indicating support for JEDEC identification.
>>
>> The documentation looks quite incomplete. "nor-jedec" sounds like
>> it's intended to be something generic. As such, it should be
>> documented in e.g.
>> Documentation/devicetree/bindings/mtd/nor-jedec.txt, not buried in
>> one particular flash device's binding. If it's not intended to be
>> generic, why isn't the existing "winbond,w25q32dw" enough?
>
> It is generic, though there are plenty of additional manufacturer/device
> pairs that could go on top of it. m25p80 was (one of?) the first
> supported, so the naming has been based on legacy, and we're in the
> process of unwinding a bit of that. If it helps, we could move the doc
> to .../mtd/spi-nor,nor-jedec.txt or something like that.
>
>> Equally, "nor-jedec" doesn't sound like the right name. It doesn't
>> differentiate between SPI and parallel NOR flash, which presumably
>> need different compatible values, since the programming model is
>> quite different, and the compatible value is supposed to
>> define/imply the SW-visible programming model.
>
> It's definitely for SPI only. There was much discussion about this a
> few months back. Somewhere along the way, it was mentioned that the
> context (SPI slave is a child of SPI master) would make this clear. I'm
> still not sure why we didn't end up with something more descriptive,
> though, like "spi-nor,nor-jedec".

What about "jedec,spi-nor"?

Is this "SERIAL FLASH DISCOVERABLE PARAMETERS (SFDP)"?
https://www.jedec.org/standards-documents/docs/jesd216b
(Don't have time to register with jedec now...)

If yes, "jedec,sfdp"? "jedec,jesd216b"?

> I'm open to change, as this binding is new in 4.1-rc1.

Indeed, as long as all users are fixed before 4.1 is released.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds
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