arch/x86/dts/serial.dtsi

   1 / {
   2         serial {
   3                 compatible = "x86-uart";
   4                 reg = <0x3f8 8>;
   5                 reg-shift = <0>;
   6                 io-mapped = <1>;
   7                 multiplier = <1>;
   8                 baudrate = <115200>;
   9         };
  10 };