I want to use GPIO65 in Jetson Nano, but error occurs "Device or resource busy "

[mayurs]

1. I want to use GPIO65 in my personal functionality and Hardware pin 127 in Jetson Nano, when I export :

echo 65 > /sys/class/gpio/export

Error occurs :

bash: echo: write error: Device or resource busy

2. When showing above error, I check debug log of GPIO that way:

sudo cat /sys/kernel/debug/gpio

Output:

  gpio-62  (                    )
 gpio-63  (                    )
 gpio-64  (                    |i2c-mux-gpio        ) out hi
 gpio-65  (                    |?                   ) out hi
 gpio-66  (                    )
 gpio-67  (                    )
 gpio-68  (                    )

This GPIO65 pin is bidirectional tristate.
gpio65.txt (541 Bytes)

[KevinFFF]

Please remove the NFC_INT usage in device tree if you want to control it as GPIO and don’t want to use it as NFC interrupt.

[mayurs]

./flash.sh -r -d /dtb/file/location jetson-nano-emmc mmcblk0p1

Above command is right for custom dtb file upload?
if not then guide me how to custom dtb file flash in jetson nano.

[KevinFFF]

Are you using jetson-nano-emmc.conf as your board config?

You could check the flash log and know which dtb is in use.
After decompiling the dtb to dts, you could modify the device tree and assemble it back to dtb.
You could apply the change through flashing the board.

$ sudo ./flash jetson-namo-emmc mmcblk0p1