Documentation/devicetree/bindings/tty/serial/of-serial.txt

   1 * UART (Universal Asynchronous Receiver/Transmitter)
   2
   3 Required 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         - "altr,16550-FIFO32"
  15         - "altr,16550-FIFO64"
  16         - "altr,16550-FIFO128"
  17         - "serial" if the port type is unknown.
  18 - reg : offset and length of the register set for the device.
  19 - interrupts : should contain uart interrupt.
  20 - clock-frequency : the input clock frequency for the UART
  21          or
  22   clocks phandle to refer to the clk used as per Documentation/devicetree
  23   /bindings/clock/clock-bindings.txt
  24
  25 Optional properties:
  26 - current-speed : the current active speed of the UART.
  27 - reg-offset : offset to apply to the mapbase from the start of the registers.
  28 - reg-shift : quantity to shift the register offsets by.
  29 - reg-io-width : the size (in bytes) of the IO accesses that should be
  30   performed on the device.  There are some systems that require 32-bit
  31   accesses to the UART (e.g. TI davinci).
  32 - used-by-rtas : set to indicate that the port is in use by the OpenFirmware
  33   RTAS and should not be registered.
  34 - no-loopback-test: set to indicate that the port does not implements loopback
  35   test mode
  36
  37 Example:
  38
  39         uart@80230000 {
  40                 compatible = "ns8250";
  41                 reg = <0x80230000 0x100>;
  42                 clock-frequency = <3686400>;
  43                 interrupts = <10>;
  44                 reg-shift = <2>;
  45         };