H6 gpio input as key stroke

Hi,

i need a gpio to trigger a key stroke.

I had an raspberry pi zero and this worked for setting up an gpio to trigger a key stroke.

For some reason I am not able to port this to my orangepi 3 lts H6 board.

I think there is some confusion because there are two pin-controller? Do I have to set the right one anywhere?

I thought the setting will be listed here like the raspberry did

root@orangepi3-lts:~# cat /sys/kernel/debug/gpio
gpiochip1: GPIOs 0-255, parent: platform/300b000.pinctrl, 300b000.pinctrl:
 gpio-79  (                    |usb0_id_det         ) in  hi
 gpio-102 (                    |gmac-3v3            ) out hi
 gpio-110 (                    |PHY reset           ) out hi ACTIVE LOW
 gpio-166 (                    |cd                  ) in  lo IRQ ACTIVE LOW
 gpio-226 (                    |ddc-en              ) out hi
 gpio-231 (                    |vcc33-wifi          ) out hi

gpiochip0: GPIOs 352-415, parent: platform/7022000.pinctrl, 7022000.pinctrl:
 gpio-356 (                    |red-led             ) out lo
 gpio-359 (                    |green-led           ) out hi
 gpio-387 (                    |reset               ) out hi ACTIVE LOW

Here's my try using gpio "PD21" aka 117 for an active low input (bias-pull-up is not active ?!)

/dts-v1/;
/plugin/;

/ {

  compatible = "allwinner,sun50i-h6";

  fragment@0 {

    target = <&pio>;

    __overlay__ {
      gpio_keys: gpio_keys {
        pins = "PD21";
        function = "gpio_in";
        bias-pull-up;			
      };
    };

  };

  fragment@1 {

    target-path = "/";

    __overlay__ {
      pinctrl-names = "default";
      pinctrl-0 = <&gpio_keys>;

      keypad: photobox {
        compatible = "gpio-keys";
        #address-cells = <1>;
        #size-cells = <0>;
        autorepeat;

        button@117 {
          label = "KEY_R";
          linux,code = <19>;  // r
          gpios = <&pio 117 1>;
        };

      };

    };

  };

};

What does `pinctrl-0 = <&gpio_keys>;` mean? Is there an automatic mapping to the right pinctrl?

I have seen that the gpio pins eg. PD21 are represented as `gpios = <&pio 3 21 0>` here ... but it doesn't help either

                                                                                                                        ^   ^

                                                                                                                            - 21 as pin offset

                                                                                                                            - 3 multiplicator (A=0, B=1, C=2, D=3 ?)

Maybe I need to build with "CONFIG_INPUT_MATRIXKMAP" ?

CONFIG_INPUT=y
CONFIG_INPUT_LEDS=y
CONFIG_INPUT_FF_MEMLESS=m
# CONFIG_INPUT_SPARSEKMAP is not set
# CONFIG_INPUT_MATRIXKMAP is not set