[RFC] pinctrl: generic: Add DT bindings

[Stephen Warren]

On 06/15/2013 02:16 PM, Heiko Stübner wrote:
> Am Samstag, 15. Juni 2013, 21:56:05 schrieb Linus Walleij:
>> On Fri, Jun 14, 2013 at 12:39 AM, Laurent Pinchart
>>
>> <laurent.pinchart at ideasonboard.com> wrote:
>>>         mmcif_pins: mmcif {
>>>         
>>>                 mux {
>>>                 
>>>                         renesas,groups = "mmc0_data8_0", "mmc0_ctrl_0";
>>>                         renesas,function = "mmc0";
>>>                 
>>>                 };
>>>                 cfg {
>>>                 
>>>                         renesas,groups = "mmc0_data8_0";
>>>                         renesas,pins = "PORT279";
>>>                         bias-pull-up = <1>;
>>
>> If I understood your code correctly that last statement can *optionally*
>> be written like just:
>>
>>  bias-pull-up;
>>
>> Without the parameter?
>>
>> I think that Heiko's implementation does this anyway.
> 
> Yep, with the fixes-series from yesterday the bias-pull-* now have a better 
> default value of <1>.
> 
> so you can do
> 	bias-pull-up;
> which is then identical to the
> 	bias-pull-up = <1>;
> above (both are valid of course).

A property with a value is an integer. One without is a Boolean. The
same property shouldn't be both.

Regarding the value representing resistance: That feels pretty odd.
Enabling a pullup and selecting the pullup resistance feel like
orthogonal options which shouldn't be bound to each-other.