projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 61ab1a90 JI |
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" | |
| 2e39e5be | 11 | - "nvidia,tegra20-uart" |
| e4305f0c | 12 | - "nxp,lpc3220-uart" |
| 61ab1a90 JI |
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 | ||
| 19 | Optional properties: | |
| 20 | - current-speed : the current active speed of the UART. | |
| 21 | - reg-offset : offset to apply to the mapbase from the start of the registers. | |
| 22 | - reg-shift : quantity to shift the register offsets by. | |
| 7423734e JI |
23 | - reg-io-width : the size (in bytes) of the IO accesses that should be |
| 24 | performed on the device. There are some systems that require 32-bit | |
| 25 | accesses to the UART (e.g. TI davinci). | |
| 61ab1a90 JI |
26 | - used-by-rtas : set to indicate that the port is in use by the OpenFirmware |
| 27 | RTAS and should not be registered. | |
| 28 | ||
| 29 | Example: | |
| 30 | ||
| 31 | uart@80230000 { | |
| 32 | compatible = "ns8250"; | |
| 33 | reg = <0x80230000 0x100>; | |
| 34 | clock-frequency = <3686400>; | |
| 35 | interrupts = <10>; | |
| 36 | reg-shift = <2>; | |
| 37 | }; |