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

Maxime Ripard maxime.ripard at free-electrons.com
Sun Nov 22 11:45:56 PST 2015


On Fri, Nov 20, 2015 at 05:45:48PM +0100, Marcus Weseloh wrote:
> 2015-11-20 17:12 GMT+01:00 Rob Herring <robh at kernel.org>:
> > On Fri, Nov 20, 2015 at 02:56:34PM +0100, Marcus Weseloh wrote:
> >> > (and the wdelay should
> >> > arguably be a core-spi thing, not a sunxi thing, but that's a separate
> >> > discussion)
> >>
> >> I've been thinking about that, but it seemed to big a change to
> >> attempt with my limited kernel hacking experience.
> >
> > It is not any bigger. You just need to document it in the core binding.
> > It would still be read by the drivers using it.
> Julien, Rob: thanks for your comments! Ok, I will make the following changes:
> - remove "sun4i,spi-wdelay" from the sun4i binding and add the
> property to the spi-bus.txt binding instead
> - remove the comment about the additional 3 cycles from the documentation
> - modfy the spi-sun4i driver to take care of the minimum 3 cycle period
> Does that sound right?
> And maybe I could also use a more descriptive name for the property,
> maybe "spi-word-wait-cycles"?

I don't think it should be in a clock-rate dependant unit. Using micro
or nano-seconds would be more appropriate I guess.


Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
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