[MinnowBoard] MinnowBoard MAX getting started with GPIO

[Darren Hart]

On 11/10/14 16:14, Martin Oldfield wrote:
> Thanks for the pointers.
> 
> I compiled a new kernel from the 3.18rc3 source and made some progress.
> 
> There are now gpio devices in /sys:
> 
> seabass mjo # ls /sys/class/gpio/
> export       gpiochip338/ gpiochip382/ gpiochip410/ unexport     
> 
> And you can export things:
> seabass mjo # echo 338 > /sys/class/gpio/export 
> seabass mjo # ls /sys/class/gpio/
> export       gpio338/     gpiochip338/ gpiochip382/ gpiochip410/ unexport     
> 
> But the GPIO numbers don't match the documentation:
> seabass mjo # cat /sys/class/gpio/gpiochip*/base
> 338
> 382
> 410
> seabass mjo # cat /sys/class/gpio/gpiochip*/ngpio
> 44
> 28
> 102

Which documentation specifically?

You will see all the GPIO lines and their pinmux configuration (set via
the firmware lpss config) with:

$ cat /sys/kernel/debug/gpio

-- 
Darren Hart
Intel Open Source Technology Center