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

Stephen Warren swarren at wwwdotorg.org
Fri May 8 14:03:40 PDT 2015


On 05/08/2015 02:15 PM, Brian Norris wrote:
> On Fri, May 08, 2015 at 02:01:40PM -0600, Stephen Warren wrote:
>> On 05/08/2015 12:43 PM, Brian Norris wrote:
>>> On Fri, May 08, 2015 at 10:00:12AM -0600, Stephen Warren wrote:
>>>> 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".
>>>
>>> I'm open to change, as this binding is new in 4.1-rc1.
>>
>> I don't believe compatible values should be interpreted according to
>> context; compatible value matching isn't implemented that way AFAIK,
>> and I'm not aware of any precedent for it to work that way.
>
> For SPI slaves, they are always nested within their SPI master/bus node.
> The master driver chooses how to probe its children. So there is some
> context-sensitivity.

That means it might be possible to implement context-sensitivity. 
However, it does not mean context-sensitivity is or should be implemented.

>> Did the discussion involve the core DT maintainers? If so, whatever
>> they decided can stick. Otherwise, the discussion should be rubn by
>> them.
>
> Yes. I never got an "ack", but Mark Rutland commented a few times and
> didn't seem to object to the name. e.g.:
>
> http://lists.infradead.org/pipermail/linux-mtd/2015-March/058275.html

Nobody pointed out in that thread the "jedec-nor" isn't remotely 
SPI-specific.



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