https://archlinuxarm.org/forum/viewtopic.php?f=31&t=8144

{{{conf
/*
 * Device Tree overlay for Adafruit 2.8" 320x240 TFT w/Cap Touch Screen for Raspberry Pi
 * The touchscreen does not (yet) work
 *
 */

/dts-v1/;
/plugin/;

/ {
   compatible = "brcm,bcm2835", "brcm,bcm2708", "brcm,bcm2709";

   fragment@0 {
      target = <&spi0>;
      __overlay__ {
         status = "okay";

         spidev@0{
            status = "disabled";
         };

         spidev@1{
            status = "disabled";
         };
      };
   };

   fragment@1 {
      target = <&gpio>;
      __overlay__ {
         pitft_pins: pitft_pins {
            brcm,pins = <25>;
            brcm,function = <1>; /* out */
         };
      };
   };

   fragment@2 {
      target = <&spi0>;
      __overlay__ {
         /* needed to avoid dtc warning */
         #address-cells = <1>;
         #size-cells = <0>;

         pitft: pitft@0{
            compatible = "ilitek,ili9341";
            reg = <0>;
            pinctrl-names = "default";
            pinctrl-0 = <&pitft_pins>;

            spi-max-frequency = <32000000>;
            rotate = <90>;
            fps = <25>;
            bgr;
            buswidth = <8>;
            dc-gpios = <&gpio 25 0>;
            debug = <0>;
         };

      };
   };

   fragment@3 {
      target-path = "/soc";
      __overlay__ {
         backlight {
            compatible = "gpio-backlight";
            gpios = <&gpio 18 0>;
            default-on;
         };
      };
   };

   __overrides__ {
      speed =   <&pitft>,"spi-max-frequency:0";
      rotate =  <&pitft>,"rotate:0";
      fps =     <&pitft>,"fps:0";
      debug =   <&pitft>,"debug:0";
   };
};
}}}