topic I.MX 8M MINI SYSFS GPIO Control Issue in i.MX Processors

I.MX 8M MINI SYSFS GPIO Control Issue

dan_hilgert — Tue, 15 Dec 2020 22:07:19 GMT

I am trying to use GPIO1_IO11 as a digital output.

Here are the commands I using in kernel space:

echo 11 > /sys/class/gpio/export

echo out > /sys/class/gpio/gpio11/direction

echo 0 > /sys/class/gpio/gpio11/value

The pin state is high no matter what.

I cat the files in /sys/class/gpio/gpio11/ and I don't see anything obviously wrong.

I have verified the pin is not being used by any other nodes in the device tree.

Has anyone ran into this before? Can anyone point me in the right direction to identify what I am doing wrong here?

Thanks

igorpadykov — Wed, 16 Dec 2020 00:23:24 GMT

Hi dan_hilgert

for i.MX8M Mini gpio usage one can look at:

Best regards
igor

dan_hilgert — Wed, 16 Dec 2020 19:10:19 GMT

igor, thanks for the pointer.

I had added the specific pin node with the info for the pin I wanted to control.

However, I was not adding the pinctl-0 property in the iomuxc node.

Once I did that, I had full control over the pin.

Thanks again,

Dan