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

/dts-v1/;
/plugin/;

#include <dt-bindings/clock/bcm2835-aux.h>

/*
 * Fake a higher clock rate to get a larger divisor, and thereby a lower
 * baudrate. The real clock is 48MHz, which we scale so that requesting
 * 38.4kHz results in an actual 31.25kHz.
 *
 *   48000000*38400/31250 = 58982400
 */

/{
	compatible = "brcm,bcm2835";

	fragment@0 {
		target-path = "/clocks";
		__overlay__ {
			midi_clk: clock@5 {
				compatible = "fixed-factor-clock";
				#clock-cells = <0>;
				clocks = <&aux BCM2835_AUX_CLOCK_UART>;
				clock-mult = <38400>;
				clock-div  = <31250>;
			};
		};
	};

	fragment@1 {
		target = <&uart1>;
		__overlay__ {
			clocks = <&midi_clk>;
		};
	};

	fragment@2 {
		target = <&aux>;
		__overlay__ {
			clock-output-names = "aux_uart", "aux_spi1", "aux_spi2";
		};
	};
};