GPIO sysfs 'default' values

[Lothar Waßmann]

Hi,

Tony Prisk writes:
> Hi Grant, Linus.
> 
> I was testing our new gpio/pinctrl driver today and noticed something a
> little weird.
> 
> I exported gpio0 via sysfs and echoed the direction value - it was 'in'.
> This pin is used to control an LCD panel, and is actually in 'out' mode.
> If I write 'in' to direction, it changes mode to 'in' and the panel
> turns off. Setting it back to 'out' and value=0, and the panel turns on
> again.
> 
> I noticed that I had no gpiochip->get_direction, so I added it, but the
> result was the same.
> 
> Any idea what I've missed?
> 
You missed to report on what platform this happens.
The platform specific GPIO driver obviously does not initialize the
shadow variables for the hardware registers correctly.


Lothar Waßmann
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