| * UART (Universal Asynchronous Receiver/Transmitter) |
| |
| Required properties: |
| - compatible : one of: |
| - "ns8250" |
| - "ns16450" |
| - "ns16550a" |
| - "ns16550" |
| - "ns16750" |
| - "ns16850" |
| - "nvidia,tegra20-uart" |
| - "nxp,lpc3220-uart" |
| - "ibm,qpace-nwp-serial" |
| - "altr,16550-FIFO32" |
| - "altr,16550-FIFO64" |
| - "altr,16550-FIFO128" |
| - "serial" if the port type is unknown. |
| - reg : offset and length of the register set for the device. |
| - interrupts : should contain uart interrupt. |
| - clock-frequency : the input clock frequency for the UART |
| or |
| clocks phandle to refer to the clk used as per Documentation/devicetree |
| /bindings/clock/clock-bindings.txt |
| |
| Optional properties: |
| - current-speed : the current active speed of the UART. |
| - reg-offset : offset to apply to the mapbase from the start of the registers. |
| - reg-shift : quantity to shift the register offsets by. |
| - reg-io-width : the size (in bytes) of the IO accesses that should be |
| performed on the device. There are some systems that require 32-bit |
| accesses to the UART (e.g. TI davinci). |
| - used-by-rtas : set to indicate that the port is in use by the OpenFirmware |
| RTAS and should not be registered. |
| - no-loopback-test: set to indicate that the port does not implements loopback |
| test mode |
| |
| Example: |
| |
| uart@80230000 { |
| compatible = "ns8250"; |
| reg = <0x80230000 0x100>; |
| clock-frequency = <3686400>; |
| interrupts = <10>; |
| reg-shift = <2>; |
| }; |
