Re: [PATCH 1/2] gpio: add pin biasing and drive mode to gpiolib

[Mark Brown <broonie@opensource.wolfsonmicro.com>]

On Tue, Apr 19, 2011 at 08:16:12AM +1000, Ben Nizette wrote:
> On 18/04/2011, at 9:59 PM, Mark Brown wrote:

> > Even if it ends up being the board code using these APIs it seems
> > sensible to have a standard API that GPIO drivers can use to expose the
> > functionality.  This will help with getting control into code Linux owns
> > (since people don't have to implement custom APIs) and will mean we can
> > do things like add control of this for device tree based boards.

> Oh I'm all for platform-specific libraries abstracting this away from the
> board code if that helps, that's certainly the way that, eg, AVR32 does it.
> It just doesn't make sense to me to bounce from the board code in to
> 'generic' gpio code then back to platform-specific implementations when
> you could cut out the middle man.

We have cross platform abstractions for lots of things - device tree,
which I mentioned, is the obvious example - and many of the GPIO
controllers are themselves cross platform as they're for off-SoC chips.