spi_mpc8xxx.c: chip select polarity problem

Grant Likely grant.likely at secretlab.ca
Fri Nov 27 05:50:05 EST 2009


On Thu, Nov 26, 2009 at 11:41 AM, Anton Vorontsov
<avorontsov at ru.mvista.com> wrote:
> On Thu, Nov 26, 2009 at 11:16:34AM -0700, Grant Likely wrote:
> [...]
>> The spi-cs-high property is defined in
>> Documentation/powerpc/dts-bindings/spi-bus.txt, but it definitely was
>> a mistake
>
> Yup.
>
>> Currently the spi-cs-high property is parsed in the
>> of_register_spi_devices() function, but the CS polarity needs to be
>> known before registering devices.  It needs to be factored out into
>> another utility function callable by spi bus drivers so that it can
>> get polarity data at probe time.
>
> Untill we have this, Torsten's patch is a real improvement, and
> works for non-broken hw/fw.
>
> So I think it should be applied.

I disagree since it only band-aids the problem and uglifies the driver
in the process.  In the immediate term the driver needs to be changed
to read the spi-cs-high property out of the child nodes before
registering the devices.  I'm not going to apply this patch.

g.

-- 
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.


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