xref: /OK3568_Linux_fs/u-boot/doc/device-tree-bindings/serial/8250.txt (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun* UART (Universal Asynchronous Receiver/Transmitter)
2*4882a593Smuzhiyun
3*4882a593SmuzhiyunRequired properties:
4*4882a593Smuzhiyun- compatible : one of:
5*4882a593Smuzhiyun	- "ns8250"
6*4882a593Smuzhiyun	- "ns16450"
7*4882a593Smuzhiyun	- "ns16550a"
8*4882a593Smuzhiyun	- "ns16550"
9*4882a593Smuzhiyun	- "ns16750"
10*4882a593Smuzhiyun	- "ns16850"
11*4882a593Smuzhiyun	- For Tegra20, must contain "nvidia,tegra20-uart"
12*4882a593Smuzhiyun	- For other Tegra, must contain '"nvidia,<chip>-uart",
13*4882a593Smuzhiyun	  "nvidia,tegra20-uart"' where <chip> is tegra30, tegra114, tegra124,
14*4882a593Smuzhiyun	  tegra132, or tegra210.
15*4882a593Smuzhiyun	- "nxp,lpc3220-uart"
16*4882a593Smuzhiyun	- "ralink,rt2880-uart"
17*4882a593Smuzhiyun	- "ibm,qpace-nwp-serial"
18*4882a593Smuzhiyun	- "altr,16550-FIFO32"
19*4882a593Smuzhiyun	- "altr,16550-FIFO64"
20*4882a593Smuzhiyun	- "altr,16550-FIFO128"
21*4882a593Smuzhiyun	- "fsl,16550-FIFO64"
22*4882a593Smuzhiyun	- "fsl,ns16550"
23*4882a593Smuzhiyun	- "serial" if the port type is unknown.
24*4882a593Smuzhiyun- reg : offset and length of the register set for the device.
25*4882a593Smuzhiyun- interrupts : should contain uart interrupt.
26*4882a593Smuzhiyun- clock-frequency : the input clock frequency for the UART
27*4882a593Smuzhiyun	 or
28*4882a593Smuzhiyun  clocks phandle to refer to the clk used as per Documentation/devicetree
29*4882a593Smuzhiyun  /bindings/clock/clock-bindings.txt
30*4882a593Smuzhiyun
31*4882a593SmuzhiyunOptional properties:
32*4882a593Smuzhiyun- current-speed : the current active speed of the UART.
33*4882a593Smuzhiyun- reg-offset : offset to apply to the mapbase from the start of the registers.
34*4882a593Smuzhiyun- reg-shift : quantity to shift the register offsets by.
35*4882a593Smuzhiyun- reg-io-width : the size (in bytes) of the IO accesses that should be
36*4882a593Smuzhiyun  performed on the device.  There are some systems that require 32-bit
37*4882a593Smuzhiyun  accesses to the UART (e.g. TI davinci).
38*4882a593Smuzhiyun- used-by-rtas : set to indicate that the port is in use by the OpenFirmware
39*4882a593Smuzhiyun  RTAS and should not be registered.
40*4882a593Smuzhiyun- no-loopback-test: set to indicate that the port does not implements loopback
41*4882a593Smuzhiyun  test mode
42*4882a593Smuzhiyun- fifo-size: the fifo size of the UART.
43*4882a593Smuzhiyun- auto-flow-control: one way to enable automatic flow control support. The
44*4882a593Smuzhiyun  driver is allowed to detect support for the capability even without this
45*4882a593Smuzhiyun  property.
46*4882a593Smuzhiyun
47*4882a593SmuzhiyunNote:
48*4882a593Smuzhiyun* fsl,ns16550:
49*4882a593Smuzhiyun  ------------
50*4882a593Smuzhiyun  Freescale DUART is very similar to the PC16552D (and to a
51*4882a593Smuzhiyun  pair of NS16550A), albeit with some nonstandard behavior such as
52*4882a593Smuzhiyun  erratum A-004737 (relating to incorrect BRK handling).
53*4882a593Smuzhiyun
54*4882a593Smuzhiyun  Represents a single port that is compatible with the DUART found
55*4882a593Smuzhiyun  on many Freescale chips (examples include mpc8349, mpc8548,
56*4882a593Smuzhiyun  mpc8641d, p4080 and ls2080a).
57*4882a593Smuzhiyun
58*4882a593SmuzhiyunExample:
59*4882a593Smuzhiyun
60*4882a593Smuzhiyun	uart@80230000 {
61*4882a593Smuzhiyun		compatible = "ns8250";
62*4882a593Smuzhiyun		reg = <0x80230000 0x100>;
63*4882a593Smuzhiyun		clock-frequency = <3686400>;
64*4882a593Smuzhiyun		interrupts = <10>;
65*4882a593Smuzhiyun		reg-shift = <2>;
66*4882a593Smuzhiyun	};
67