Re: [spi-devel-general] Re: question on spi_bitbang

From: Stephen Street
Date: Fri Mar 31 2006 - 13:16:55 EST


On Fri, 2006-03-31 at 10:11 -0800, David Brownell wrote:
> I don't know how your particular hardware works, but if you have a
> real SPI controller it would probably be more natural to have your
> setup() function handle that mode register earlier, out of the main
> transfer loop ... unless that mode register is shared among all
> chipselects, in which case you'd use the setup_transfer() call for
> that, inside the transfer loop. (That call hasn't yet been merged
> into the mainline kernel yet; it's in the MM tree.)
>
Is setup_transfer() a change to framework API or just the bit_bang
driver?

> The chipselect() call should only affect the chipselect signal and,
> when you're activating a chip, its initial clock polarity. Though
> if you're not using the latest from the MM tree, that's also your
> hook for ensuring that the SPI mode is set up right.
>
Ditto?

-Stephen

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