[PATCH v2] spi: dts: sun4i: Add support for inter-word wait cycles using the SPI Wait Clock Register

Marcus Weseloh mweseloh42 at gmail.com
Sun Dec 13 13:52:12 PST 2015


2015-12-13 22:07 GMT+01:00 Maxime Ripard <maxime.ripard at free-electrons.com>:
[...]
>> There is one review comment that I didn't address: Rob Herring suggested
>> that this should be in the core-binding rather than in sun4i. I checked
>> many of the hardware manuals of other SPI drivers and it looks to me like
>> this hardware based inter-word delay is a feature that not many SPI
>> controllers offer. And the SPI core currently has no way to control an
>> inter-word delay, only inter-message. So I would like to propose this again
>> as a sun4i binding, as it targets a sun4i (or sunxi?) specific hardware
>> feature.
>
> Only a few of them justify to have this in the framework. There's a
> bunch of controllers that support such a feature, and it definitely
> belongs in the core.
>
> The point of the framework is not to be the least common denominator,
> it's about having as much code in common as possible, and it
> definitely falls into that category.

Ok, now I understand. I did indeed think that the SPI core is more
like a least common denominator. So I will add the property to the
spi-core binding, as initially requested by Rob and send a v3.

Thanks for the review, Maxime!

Marcus



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