[PATCH 2/4] [OF] spi_of: add support for dedicated SPI constructors

Grant Likely grant.likely at secretlab.ca
Thu May 22 06:07:12 EST 2008

On Wed, May 21, 2008 at 2:00 PM, Guennadi Liakhovetski
<g.liakhovetski at gmx.de> wrote:
> On Wed, 21 May 2008, Grant Likely wrote:
>> On Wed, May 21, 2008 at 1:20 PM, Guennadi Liakhovetski
>> <g.liakhovetski at gmx.de> wrote:
>> >
>> > Right again - _rare_ corner cases. Whereas we are talking about _all_ SPI
>> > busses, maybe apart from those, where the controller itself switches CSs
>> > in a well-defined way, and the driver doesn't need any additional
>> > information to handle this.
>> Ah, I see where we are crossing our wires.  I was talking about the
>> case of registering spi devices.  I agree that the spi bus should not
>> need any additional information.
> No, sorry for not making it clear. I wrote "busses" because on those
> controllers, that control CS themselves _devices_ don't need any
> additional info. But I meant, that describing SPI _devices_ should be done
> in only one way or another - either using fdt, or platform data, not both.

Yes, I agree with that too... with the one caveat that platform code
should have some method to supplement the data in the device tree
*only when it is absolutely necessary to do so*.  (note: I say
'platform code' here, not 'platform data'.  They are two different
things)  I make no claims on what that method should be at this time.


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

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