arch/arm/boot/dts/overlays/midi-uart0-overlay.dts

   1 /dts-v1/;
   2 /plugin/;
   3
   4 #include <dt-bindings/clock/bcm2835.h>
   5
   6 /*
   7  * Fake a higher clock rate to get a larger divisor, and thereby a lower
   8  * baudrate. The real clock is 48MHz, which we scale so that requesting
   9  * 38.4kHz results in an actual 31.25kHz.
  10  *
  11  *   48000000*38400/31250 = 58982400
  12  */
  13
  14 /{
  15         compatible = "brcm,bcm2835";
  16
  17         fragment@0 {
  18                 target-path = "/";
  19                 __overlay__ {
  20                         midi_clk: midi_clk {
  21                                 compatible = "fixed-clock";
  22                                 #clock-cells = <0>;
  23                                 clock-output-names = "uart0_pclk";
  24                                 clock-frequency = <58982400>;
  25                         };
  26                 };
  27         };
  28
  29         fragment@1 {
  30                 target = <&uart0>;
  31                 __overlay__ {
  32                         clocks = <&midi_clk>,
  33                                  <&clocks BCM2835_CLOCK_VPU>;
  34                 };
  35         };
  36 };