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From: David Brownell <david-b@pacbell.net>
To: Pavel Machek <pavel@ucw.cz>
Subject: Re: [patch/rfc 2.6.25-git] gpio: sysfs interface
Date: Sat, 17 May 2008 15:14:06 -0700
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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.

- Dave