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Date: Thu, 5 Jun 2008 09:53:33 -0600
From: "Grant Likely" <grant.likely@secretlab.ca>
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To: "Jochen Friedrich" <jochen@scram.de>
Subject: Re: "cell-index" vs. "index" vs. no index in I2C device nodes
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On Thu, Jun 5, 2008 at 9:52 AM, Jochen Friedrich <jochen@scram.de> wrote:
> Hi Grant,
>
>> if you need explicit indexing then use an alias.  My opinion however
>> is that explicit indexing is unnecessary and is just an artifact of
>> current i2c subsystem internals.  There is already enough information
>> in the device tree to match i2c devices with i2c busses without
>> resorting to indexes.
>
> True. However, there are currently drivers which need platform data for
> its initialisation (like drivers/gpio/pca953x.c). Unless these drivers
> are rewritten, they can't be loaded just by parsing the device tree, so
> they must be loaded from platform init code and here the adapter index
> is needed to attach the driver.

... which means that platform code is responsible to figure it out.
Don't encode it into the device tree.

Besides, this is just a binding.  I see absolutely no problem adding
probe code to the bindings to extract data from the device tree.

Cheers,
g.

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