From: David Brownell <david-b@pacbell.net>
To: Vitaly Wool <vwool@ru.mvista.com>
Subject: Re: [PATCH 2.6-git] SPI: add set_clock() to bitbang
Date: Thu, 22 Dec 2005 13:37:39 -0800
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> >This is actually not needed.  Clocks are set through the setup() method
> ...
>
> Where is it supposed to call setup? I guess it's anyway gonna be 
> per-transfer, right?
> Or am I missing something?

When the device is created, the core calls setup() to get things like
chipselect polarity sorted out and put into the inactive state.   That
matches the board-specific defaults associated with that device, which
would be a function of voltage, routing, and more.

And from then on, it'd be rare to ever call setup() again ... though
drivers certainly could do that between spi_message interactions with
a given device.

- Dave
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