Kernel-4.18.0-80.el8_sun4i-lradc-keys

Allwinner sun4i low res adc attached tablet keys

Required properties:

• compatible: “allwinner,sun4i-a10-lradc-keys”
• reg: mmio address range of the chip
• interrupts: interrupt to which the chip is connected
• vref-supply: powersupply for the lradc reference voltage

Each key is represented as a sub-node of “allwinner,sun4i-a10-lradc-keys”:

Required subnode-properties:
- label: Descriptive name of the key.
- linux,code: Keycode to emit.
- channel: Channel this key is attached to, must be 0 or 1.
- voltage: Voltage in µV at lradc input when this key is pressed.

Example:

#include <dt-bindings/input/input.h>

lradc: lradc@1c22800 {
    compatible = "allwinner,sun4i-a10-lradc-keys";
    reg = <0x01c22800 0x100>;
    interrupts = <31>;
    vref-supply = <&reg_vcc3v0>;

    button@191 {
        label = "Volume Up";
        linux,code = <KEY_VOLUMEUP>;
        channel = <0>;
        voltage = <191274>;
    };

    button@392 {
        label = "Volume Down";
        linux,code = <KEY_VOLUMEDOWN>;
        channel = <0>;
        voltage = <392644>;
    };

    button@601 {
        label = "Menu";
        linux,code = <KEY_MENU>;
        channel = <0>;
        voltage = <601151>;
    };

    button@795 {
        label = "Enter";
        linux,code = <KEY_ENTER>;
        channel = <0>;
        voltage = <795090>;
    };

    button@987 {
        label = "Home";
        linux,code = <KEY_HOMEPAGE>;
        channel = <0>;
        voltage = <987387>;
    };
};