linux/Documentation/devicetree/bindings/serial/arc-uart.txt

* Synopsys ARC UART : Non standard UART used in some of the ARC FPGA boards

Required properties:
- compatible		: "snps,arc-uart"
- reg			: offset and length of the register set for the device.
- interrupts		: device interrupt
- clock-frequency	: the input clock frequency for the UART
- current-speed		: baud rate for UART

e.g.

arcuart0: serial@c0fc1000 {
	compatible = "snps,arc-uart";
	reg = <0xc0fc1000 0x100>;
	interrupts = <5>;
	clock-frequency = <80000000>;
	current-speed = <115200>;
	status = "okay";
};

Note: Each port should have an alias correctly numbered in "aliases" node.

e.g.
aliases {
	serial0 = &arcuart0;
};