A long time ago, that I started the question, but a few days ago, I started again to solve it.
And with the help of several AI, I found a working solution. This is the working overlay:
/dts-v1/;
/plugin/;
/*
* NanoPI Neo2 H5 - OTG USB with switchable VBUS
* Allows SD-Card as USB device on OTG port with GPIO-controlled power
*
* Key points:
* - fragment 0: dr_mode "otg" enables dual-role (host+device detection)
* - fragment 1: Removing usb0_id_det-gpios prevents "External vbus detected" error
* - fragment 2: Removing gpio property from regulator keeps GPIO 354 (PR2) free for manual control
* - fragment 3: GPIO 354 is controlled via usb.sh script (echo 1/0 to /sys/class/gpio/gpio354/value)
*
* GPIO 354 (PR2) state:
* 1 = VBUS ON (USB device recognized)
* 0 = VBUS OFF (USB device disconnected)
*/
/ {
compatible = "allwinner,sun50i-h5";
fragment@0 {
target = <&usb_otg>;
__overlay__ {
dr_mode = "otg";
status = "okay";
};
};
fragment@1 {
target = <&usbphy>;
__overlay__ {
usb0_id_det-gpios;
};
};
fragment@2 {
target-path = "/usb0-vbus";
__overlay__ {
gpio;
status = "okay";
};
};
fragment@3 {
target = <&r_pio>;
__overlay__ {
usb0_vbus_pin: usb0_vbus_pin {
pins = "PR2";
function = "gpio_out";
output-high;
};
};
};
};
This allows the standard GPIO controls using sysfs in /sys/class/gpio.
I'm using the kernel Linux nanopineo2 6.6.75-current-sunxi64 on Armbian 25.11.2 bookworm (32 bit userland).
Hope this helps everybody trying to achive the same 😉
