Re: [RFC] Proposal: common kernel-wide GPIO interface

[Robert Schwebel <r.schwebel@pengutronix.de>]

On Tue, Aug 01, 2006 at 03:25:32PM -0600, Jim Cromie wrote:
> >I've attached the gpio framework we have developed a while ago; it is
> >not ready for upstream, only tested on pxa and has probably several
> >other drawbacks, but may be a start for your activities. One of the
> >problems we've recently seen is that for example on PowerPCs you don't
> >have such a clear "this is gpio pin x" nomenclature, so the question
> >would be how to do the mapping here.
> >
> >Robert 
> >  
> this is cool to see.  Using a class-driver is very different from the 
> vtable-approach
> that I used (struct nsc_gpio_ops) in pc8736x_gpio and scx200_gpio.
> 
> Are any of the limitation youve cited above related to the 
> /sys/class/gpio paths below ?
> 
> +	  To set pin 63 to low (to start the motor) do a:
> +	   $ echo 0 > /sys/class/gpio/gpio63/level
> +	  Or to stop the motor again:
> +	   $ echo 1 > /sys/class/gpio/gpio63/level
> +	  To get the level of the key (pin 8) do:
> +	   $ cat /sys/class/gpio/gpio8/level
> +	  The result will be 1 or 0.
> +
> +	  To add new GPIO pins at runtime (lets say pin 88 should be an 
> input)
> +	  you can do a:
> +	   $ echo 88:in > /sys/class/gpio/map_gpio
> +	  The same with a new GPIO pin 95, it should be an output and at 
> high level:
> +	   $ echo 95:out:hi > /sys/class/gpio/map_gpio
> +
 
Please re-read my original mail. 

Robert
-- 
 Dipl.-Ing. Robert Schwebel | http://www.pengutronix.de
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