tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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 - "nvidia,tegra20-uart"
12 - "nxp,lpc3220-uart"
13 - "ibm,qpace-nwp-serial"
14 - "serial" if the port type is unknown.
15- reg : offset and length of the register set for the device.
16- interrupts : should contain uart interrupt.
17- clock-frequency : the input clock frequency for the UART
18 or
19 clocks phandle to refer to the clk used as per Documentation/devicetree
20 /bindings/clock/clock-bindings.txt
21
22Optional properties:
23- current-speed : the current active speed of the UART.
24- reg-offset : offset to apply to the mapbase from the start of the registers.
25- reg-shift : quantity to shift the register offsets by.
26- reg-io-width : the size (in bytes) of the IO accesses that should be
27 performed on the device. There are some systems that require 32-bit
28 accesses to the UART (e.g. TI davinci).
29- used-by-rtas : set to indicate that the port is in use by the OpenFirmware
30 RTAS and should not be registered.
31- no-loopback-test: set to indicate that the port does not implements loopback
32 test mode
33
34Example:
35
36 uart@80230000 {
37 compatible = "ns8250";
38 reg = <0x80230000 0x100>;
39 clock-frequency = <3686400>;
40 interrupts = <10>;
41 reg-shift = <2>;
42 };