Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / Documentation / devicetree / bindings / serial / 8250.txt

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+* UART (Universal Asynchronous Receiver/Transmitter)
+
+Required properties:
+- compatible : one of:
+       - "ns8250"
+       - "ns16450"
+       - "ns16550a"
+       - "ns16550"
+       - "ns16750"
+       - "ns16850"
+       - For Tegra20, must contain "nvidia,tegra20-uart"
+       - For other Tegra, must contain '"nvidia,<chip>-uart",
+         "nvidia,tegra20-uart"' where <chip> is tegra30, tegra114, tegra124,
+         tegra132, or tegra210.
+       - "nxp,lpc3220-uart"
+       - "ralink,rt2880-uart"
+       - "ibm,qpace-nwp-serial"
+       - "altr,16550-FIFO32"
+       - "altr,16550-FIFO64"
+       - "altr,16550-FIFO128"
+       - "fsl,16550-FIFO64"
+       - "fsl,ns16550"
+       - "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
+- fifo-size: the fifo size of the UART.
+- auto-flow-control: one way to enable automatic flow control support. The
+  driver is allowed to detect support for the capability even without this
+  property.
+
+Note:
+* fsl,ns16550:
+  ------------
+  Freescale DUART is very similar to the PC16552D (and to a
+  pair of NS16550A), albeit with some nonstandard behavior such as
+  erratum A-004737 (relating to incorrect BRK handling).
+
+  Represents a single port that is compatible with the DUART found
+  on many Freescale chips (examples include mpc8349, mpc8548,
+  mpc8641d, p4080 and ls2085a).
+
+Example:
+
+       uart@80230000 {
+               compatible = "ns8250";
+               reg = <0x80230000 0x100>;
+               clock-frequency = <3686400>;
+               interrupts = <10>;
+               reg-shift = <2>;
+       };