[PATCH] arm pxa: remove "direction input" forcing for IRQ GPIOs

[giometti@enneenne.com (Rodolfo Giometti)]

On Tue, Nov 17, 2009 at 01:43:34PM +0100, Daniel Mack wrote:
> On Tue, Nov 17, 2009 at 01:37:21PM +0100, Rodolfo Giometti wrote:
> > On Tue, Nov 17, 2009 at 01:34:22PM +0100, Daniel Mack wrote:
> > > On Tue, Nov 17, 2009 at 01:05:01PM +0100, Rodolfo Giometti wrote:
> > > > On Tue, Nov 17, 2009 at 12:44:29PM +0100, Daniel Mack wrote:
> > > > > On Tue, Nov 17, 2009 at 12:21:46PM +0100, Rodolfo Giometti wrote:
> > > > > > PXA CPUs may use their GPIOs as IRQ lines even if they are selected as
> > > > > > outputs (see for example figure 24-1 into PXA27x Processor Family
> > > > > > Developer's Manual). So forcing GPIOs IRQ lines as inputs is not
> > > > > > correct.
> > > > > > 
> > > > > > Programmers should set up GPIOs direction according to their usage and
> > > > > > the function pxa_gpio_irq_type() should simply enable the IRQ
> > > > > > detection.
> > > > > 
> > > > > Interesting. Is this an academic issue or do you actually use that?
> > > > > That would mean you externally drive the IO pin level to something else
> > > > > than the output driver provides, which isn't healthy at all.
> > > > 
> > > > It's a real configuration with no electrical drawbacks at all! Of
> > > > course the driver's output must be passive (I use it to detect a CARD
> > > > insert) but it's functional.
> > > 
> > > For such situations, the pullup/pulldown functions are normally used.
> > > Have you tried that?
> > 
> > Yes, the code has been tested on my board and it works perfectly.
> 
> What I mean is a mfp_cfg_t configuration as input pin with pull flags
> MFP_PULL_{HIGH,LOW} set.

I see... no I didn't noticed such possibility.

however I suppose that even using such flags my patch is needed in
order to avoid pxa_gpio_irq_type() forcing the input direction...

Ciao,

Rodolfo

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