Using a linux-kernel compiled as it is described here, I'm trying to make a led blinking following this wiki: Linux GPIO Driver. I'm working with a Zybo-board of Xilinx.
I enabled the kernel options:
CONFIG_GPIO_SYSFS=y
CONFIG_SYSFS=y
CONFIG_GPIO_XILINX=y
I checked that I have mounted in /sys the SysFs
I want to configure the pin 7 of the MIO port because it is attached to the led LD4 in the board. So I used this expression:
echo 7 > /sys/class/gpio/export
And I always obtain this error:
export_store: invalid GPIO 7
ash: write error: Invalid argument
I have also tried to export the values 145 (138+7)
because of the explanation I found here: forum_link and 86 because this guy got the things working basic_example. But I always obtained the same error.
Could you give me some help? Maybe a I have to use other offset? Or is it more related with permission configuration??