arch/arm/boot/dts/overlays/uart1-overlay.dts

   1 /dts-v1/;
   2 /plugin/;
   3
   4 /{
   5         compatible = "brcm,bcm2835";
   6
   7         fragment@0 {
   8                 target = <&uart1>;
   9                 __overlay__ {
  10                         pinctrl-names = "default";
  11                         pinctrl-0 = <&uart1_pins>;
  12                         status = "okay";
  13                 };
  14         };
  15
  16         fragment@1 {
  17                 target = <&gpio>;
  18                 __overlay__ {
  19                         uart1_pins: uart1_ovl_pins {
  20                                 brcm,pins = <14 15>;
  21                                 brcm,function = <2>; /* alt5 */
  22                                 brcm,pull = <0 2>;
  23                         };
  24                 };
  25         };
  26
  27         fragment@2 {
  28                 target-path = "/chosen";
  29                 __overlay__ {
  30                         bootargs = "8250.nr_uarts=1";
  31                 };
  32         };
  33
  34         __overrides__ {
  35                 txd1_pin = <&uart1_pins>,"brcm,pins:0";
  36                 rxd1_pin = <&uart1_pins>,"brcm,pins:4";
  37         };
  38 };