Re: [PATCH] ARM: dts: i.MX27: Configure GPIOs as "input" by default

[Alexander Shiyan]

> > On Tue, Dec 03, 2013 at 04:46:27PM +0800, Shawn Guo wrote:
> > > On Sat, Nov 30, 2013 at 11:03:20AM +0400, Alexander Shiyan wrote:
> > > > This patch changes the default direction for pins used
> > > > as GPIO to "input". This prevents a short circuit on the
> > > > configuration stage when GPIO-pin is connected to the
> > > > other output pin.
> > > 
> > > Markus,
> > > 
> > > Does it make sense to you?
> > 
> > I am not sure if this really happens. However, it does make sense and I
> > can't see any disadvantages in changing the default GPIO mux direction to
> > input.
> > 
> What happens, if the bootloader already set up a pin as output and
> linux later does the pinconfig stuff?
> If the pin is reconfigured as input then, this may produce an unwanted
> glitch on the pin. IMO the pinconfig driver should not touch the pin
> direction, but leave it to the gpio driver to set that up. 

Such pin can be overridden by board DTS.

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