1* UART (Universal Asynchronous Receiver/Transmitter)
2
3Required properties:
4- compatible : one of:
5	- "ns8250"
6	- "ns16450"
7	- "ns16550a"
8	- "ns16550"
9	- "ns16750"
10	- "ns16850"
11	- For Tegra20, must contain "nvidia,tegra20-uart"
12	- For other Tegra, must contain '"nvidia,<chip>-uart",
13	  "nvidia,tegra20-uart"' where <chip> is tegra30, tegra114, tegra124,
14	  tegra132, or tegra210.
15	- "nxp,lpc3220-uart"
16	- "ralink,rt2880-uart"
17	- "ibm,qpace-nwp-serial"
18	- "altr,16550-FIFO32"
19	- "altr,16550-FIFO64"
20	- "altr,16550-FIFO128"
21	- "fsl,16550-FIFO64"
22	- "fsl,ns16550"
23	- "serial" if the port type is unknown.
24- reg : offset and length of the register set for the device.
25- interrupts : should contain uart interrupt.
26- clock-frequency : the input clock frequency for the UART
27	 or
28  clocks phandle to refer to the clk used as per Documentation/devicetree
29  /bindings/clock/clock-bindings.txt
30
31Optional properties:
32- current-speed : the current active speed of the UART.
33- reg-offset : offset to apply to the mapbase from the start of the registers.
34- reg-shift : quantity to shift the register offsets by.
35- reg-io-width : the size (in bytes) of the IO accesses that should be
36  performed on the device.  There are some systems that require 32-bit
37  accesses to the UART (e.g. TI davinci).
38- used-by-rtas : set to indicate that the port is in use by the OpenFirmware
39  RTAS and should not be registered.
40- no-loopback-test: set to indicate that the port does not implements loopback
41  test mode
42- fifo-size: the fifo size of the UART.
43- auto-flow-control: one way to enable automatic flow control support. The
44  driver is allowed to detect support for the capability even without this
45  property.
46
47Note:
48* fsl,ns16550:
49  ------------
50  Freescale DUART is very similar to the PC16552D (and to a
51  pair of NS16550A), albeit with some nonstandard behavior such as
52  erratum A-004737 (relating to incorrect BRK handling).
53
54  Represents a single port that is compatible with the DUART found
55  on many Freescale chips (examples include mpc8349, mpc8548,
56  mpc8641d, p4080 and ls2085a).
57
58Example:
59
60	uart@80230000 {
61		compatible = "ns8250";
62		reg = <0x80230000 0x100>;
63		clock-frequency = <3686400>;
64		interrupts = <10>;
65		reg-shift = <2>;
66	};
67