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

[David Brownell <david-b@pacbell.net>]

On Monday 28 April 2008, Ben Nizette wrote:
> > > > 
> > > > Sysfs attributes are supposed to be pollable.  I've not done it,
> > > > but fs/sysfs/file.c::sysfs_notify() looks relevant ...
> > > 
> > > Right, that'll work.
> > 
> > OK.  In that case, I think I should plan to rename the "direction"
> > attribute as "configuration" or something a bit broader ... so that
> > writing "irq" (or maybe "rising", "falling", "bothedges", "poll")
> > would eventually configure it as an input with an IRQ handler.
> 
> Good plan, unless you'd prefer to see "direction" and "interrupt" config
> separate.  I have no real preference but IMO
>   echo "falling" > interrupt
> makes more immediate sense than
>   echo "falling" > configuration

OK, I'll leave it be then.  Given that not all GPIOs support
interrupts, I used the "poll" example intentionally ... being
able to poll every N seconds (milliseconds?) may be important.


> > 
> > Whenever someone contributes such an async notification scheme,
> > that is.  ;)
> 
> ;)