Hi,

Alexander Shiyan wrote:

quoted

quoted

On Tue, Dec 03, 2013 at 04:46:27PM +0800, Shawn Guo wrote:

quoted

On Sat, Nov 30, 2013 at 11:03:20AM +0400, Alexander Shiyan wrote:

quoted

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.

So, which pins will be configured with the default direction?
If pins are not stated in DT they should be not configured at all, I
suppose.


Lothar Wa?mann
-- 
___________________________________________________________

Ka-Ro electronics GmbH | Pascalstra?e 22 | D - 52076 Aachen
Phone: +49 2408 1402-0 | Fax: +49 2408 1402-10
Gesch?ftsf?hrer: Matthias Kaussen
Handelsregistereintrag: Amtsgericht Aachen, HRB 4996

www.karo-electronics.de | info at karo-electronics.de
___________________________________________________________