Re: [patch/rfc 2.6.25-git] gpio: sysfs interface

From: Pavel Machek
Date: Mon May 19 2008 - 18:39:10 EST


On Sat 2008-05-17 15:14:06, David Brownell wrote:
> On Friday 02 May 2008, Pavel Machek wrote:
> >
> > > >   echo "export 23" > /sys/class/gpio/control
> > > >     ... will gpio_request(23, "sysfs") and gpio_export(23); use
> > > >     /sys/class/gpio/gpio-23/direction to configure it.
> > > >   echo "unexport 23" > /sys/class/gpio/control
> > > >     ... will gpio_free(23)
> > >
> > > hm, does ths sysfs one-value-per-file rule apply to writes?
> >
> > Having seen ibm acpi interface... yes, that rule should be aplied for
> > writes, too.
>
> The latest version of this patch, which I'll post soonish,
> follows the suggestion to have one file for the "export"
> operation and another for "unexport".
>
>
> > What about mkdir gpio-N to export it?
>
> Ugh. That would create way more complication than I want
> to see here. I thought about that early on, and decided
> that was Not The Way To Go.

...but it would be consistent with configfs... and face it... doing
echo > file to make a directory is seriously ugly.
Pavel
--
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