arch/x86/dts/serial.dtsi

   1 / {
   2         serial: serial {
   3                 compatible = "x86-uart";
   4                 reg = <0x3f8 8>;
   5                 reg-shift = <0>;
   6                 clock-frequency = <1843200>;
   7                 current-speed = <115200>;
   8         };
   9 };