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Based on kernel version 3.15.4. Page generated on 2014-07-07 09:01 EST.

1	* Atmel Universal Synchronous Asynchronous Receiver/Transmitter (USART)
2	
3	Required properties:
4	- compatible: Should be "atmel,<chip>-usart"
5	  The compatible <chip> indicated will be the first SoC to support an
6	  additional mode or an USART new feature.
7	- reg: Should contain registers location and length
8	- interrupts: Should contain interrupt
9	- clock-names: tuple listing input clock names.
10		Required elements: "usart"
11	- clocks: phandles to input clocks.
12	
13	Optional properties:
14	- atmel,use-dma-rx: use of PDC or DMA for receiving data
15	- atmel,use-dma-tx: use of PDC or DMA for transmitting data
16	- rts-gpios: specify a GPIO for RTS line. It will use specified PIO instead of the peripheral
17	  function pin for the USART RTS feature. If unsure, don't specify this property.
18	- add dma bindings for dma transfer:
19		- dmas: DMA specifier, consisting of a phandle to DMA controller node,
20			memory peripheral interface and USART DMA channel ID, FIFO configuration.
21			Refer to dma.txt and atmel-dma.txt for details.
22		- dma-names: "rx" for RX channel, "tx" for TX channel.
23	
24	<chip> compatible description:
25	- at91rm9200:  legacy USART support
26	- at91sam9260: generic USART implementation for SAM9 SoCs
27	
28	Example:
29	- use PDC:
30		usart0: serial@fff8c000 {
31			compatible = "atmel,at91sam9260-usart";
32			reg = <0xfff8c000 0x4000>;
33			interrupts = <7>;
34			clocks = <&usart0_clk>;
35			clock-names = "usart";
36			atmel,use-dma-rx;
37			atmel,use-dma-tx;
38			rts-gpios = <&pioD 15 0>;
39		};
40	
41	- use DMA:
42		usart0: serial@f001c000 {
43			compatible = "atmel,at91sam9260-usart";
44			reg = <0xf001c000 0x100>;
45			interrupts = <12 4 5>;
46			clocks = <&usart0_clk>;
47			clock-names = "usart";
48			atmel,use-dma-rx;
49			atmel,use-dma-tx;
50			dmas = <&dma0 2 0x3>,
51			       <&dma0 2 0x204>;
52			dma-names = "tx", "rx";
53		};
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