Subject: Re: GPIO - marking individual pins (not) available in device tree

From: Anton Vorontsov <[email-masked]>
Date: Fri, 24 Oct 2008 21:01:28 +0400

On Fri, Oct 24, 2008 at 08:41:20PM +0400, Anton Vorontsov wrote:
[...]
> > So, how do we define in a bank of GPIOs, which ones are free for use, 
> > without them being attached to a device and given as a "gpios" property?
> >
> > Would we suggest a node;
> >
> > gpio-header {
> > 	compatible = "bplan,efika-gpio";
> > 	gpios = <&gpio-standard 16 0 17 0>;
> > };
> >
> > gpio-header2 {
> > 	compatible = "bplan,efika-gpio-wkup";
> > 	gpios = <&gpio-wkup 18 0>;
> > };
>
> IMO this looks very reasonable. You properly describe the hardware:
> physical device (header) and its resources.

If there are actually two headers, that is. If you use two nodes
just to specify which gpio is wkup, that is's a bit ugly... Why not

gpio-header {
	compatible = "bplan,<board>-gpio-header";
	gpios = <&standard 16 0
		 &standard 17 0
		 &wakeup 18 0>;
}

And the driver whould know that on this particular <board>
third gpio is the wakeup one?

-- 
Anton Vorontsov
email: [email-masked]
irc://irc.freenode.net/bd2