Re[3]: [PATCH] ARM: iomux-mx51: Always define PU E for pins used as GPIO

Alexander Shiyan shc_work at mail.ru
Wed May 22 03:17:36 EDT 2013


> Alexander Shiyan writes:
> > > On Tue, May 21, 2013 at 12:27:25PM +0400, Alexander Shiyan wrote:
> > > > This patch adds a PUE bit for pins which used as GPIO. This allow
> > > > to use the GPIOs correctly as inputs when source is open-drain with
> > > > external pullup resistor (IRQ open-drain outputs for example).
> > > 
> > > I don't understand. If there's an external pullup why do you want to
> > > turn on the internal one?
> > 
> > It is just switch off keeper circuit.
> > 
> If you want to switch the keeper circuit off why don't you do that by
> removing PAD_CTL_PKE rather than adding PAD_CTL_PUE?

Again, I do not know which the solution here is better. If we remove
the PKE bit, for some pins it will be removed the default pullup/pulldown (PUS = 0),
so it may affect the some running configuration.

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