GPIO differences L4T 32.6 and L4T 35.1 on Xavier AGX

[brootux]

I used the L4T 32.6 on my Xavier AGX before and the following controlled GPIO pin Q2 perfectly fine:

> echo "420" > /sys/class/gpio/export
> cat /sys/class/gpio/gpio420/direction
in

This did not work on L4T35.1.0 anymore and so i read a lot and found out that the “gpio base number” has changed from 288 to 305, so after recalculating everything ill tried

> echo "437" > /sys/class/gpio/export
> cat /sys/class/gpio/PQ.02/direction
in

Which is probably what i should do now. Unfortunately i have to use a propritary, pre-compiled library which has the old behavior hard-coded.

Two Questions:

• Is it possible (and how) to set the “GPIO base number” from 305 back to 288 (e.g. via kernel-patch or devicetree change)
• Is it possible (and how) to get the old folder-names back when exporting a GPIO (PQ.02 has to be gpio420 again)

[JerryChang]

hello brootux,

Jetpack-5.0.2/ l4t-r35.1 is moving kernel version to 5.10, it also changed the GPIO allocation ranges. since you’re going to work on l4t-r35.1, it’s unrealistic to fall-back the base-number.
please refer to developer guide for the approaches To check the GPIO number. you may update your drivers accordingly.