[RFC] pinctrl: generic: Add DT bindings

Laurent Pinchart laurent.pinchart at ideasonboard.com
Sun Jun 16 09:52:59 EST 2013


Hi Linus,

On Sunday 16 June 2013 01:51:32 Linus Walleij wrote:
> On Sun, Jun 16, 2013 at 1:35 AM, Laurent Pinchart wrote:
> > On Saturday 15 June 2013 22:16:13 Heiko Stübner wrote:
> >> Am Samstag, 15. Juni 2013, 21:56:05 schrieb Linus Walleij:
> >> 
> >> Disable would the be either
> >> 
> >>       bias-disable;
> >> 
> >> or
> >> 
> >>       bias-pull-up = <0>;
> >> 
> >> A driver should probably handle both, as both are valid pinconf options
> >> or this.
> > 
> > I feel a bit uneasy about that. Do we really need to support two different
> > ways to achieve the same result ?
> 
> In this specific case I think yes, but not on all options.
> 
> As dicussed earlier this was designed for systems where
> you could set the pull-up resistance, like
> 
> bias-pull-up = <600000>;
> 
> would give 600kOhm pull up.
> 
> In most existing systems that is silly, as they can't specify it, so they
> should be able to do just:
> 
> bias-pull-up;
> 
> as that is all they can do. If we have to cut one way, we should cut the
> former until such a system appears.

I'm fine with bias-pull-up = <1>; vs bias-pull-up;. What bothers me a bit is 
bias-pull-up = <0>; vs bias-disable;.

-- 
Regards,

Laurent Pinchart



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