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Based on kernel version 4.1. Page generated on 2015-06-28 12:10 EST.

1	* Atmel Universal Synchronous Asynchronous Receiver/Transmitter (USART)
2	
3	Required properties:
4	- compatible: Should be "atmel,<chip>-usart" or "atmel,<chip>-dbgu"
5	  The compatible <chip> indicated will be the first SoC to support an
6	  additional mode or an USART new feature.
7	  For the dbgu UART, use "atmel,<chip>-dbgu", "atmel,<chip>-usart"
8	- reg: Should contain registers location and length
9	- interrupts: Should contain interrupt
10	- clock-names: tuple listing input clock names.
11		Required elements: "usart"
12	- clocks: phandles to input clocks.
13	
14	Optional properties:
15	- atmel,use-dma-rx: use of PDC or DMA for receiving data
16	- atmel,use-dma-tx: use of PDC or DMA for transmitting data
17	- {rts,cts,dtr,dsr,rng,dcd}-gpios: specify a GPIO for RTS/CTS/DTR/DSR/RI/DCD line respectively.
18	  It will use specified PIO instead of the peripheral function pin for the USART feature.
19	  If unsure, don't specify this property.
20	- add dma bindings for dma transfer:
21		- dmas: DMA specifier, consisting of a phandle to DMA controller node,
22			memory peripheral interface and USART DMA channel ID, FIFO configuration.
23			Refer to dma.txt and atmel-dma.txt for details.
24		- dma-names: "rx" for RX channel, "tx" for TX channel.
25	
26	<chip> compatible description:
27	- at91rm9200:  legacy USART support
28	- at91sam9260: generic USART implementation for SAM9 SoCs
29	
30	Example:
31	- use PDC:
32		usart0: serial@fff8c000 {
33			compatible = "atmel,at91sam9260-usart";
34			reg = <0xfff8c000 0x4000>;
35			interrupts = <7>;
36			clocks = <&usart0_clk>;
37			clock-names = "usart";
38			atmel,use-dma-rx;
39			atmel,use-dma-tx;
40			rts-gpios = <&pioD 15 GPIO_ACTIVE_LOW>;
41			cts-gpios = <&pioD 16 GPIO_ACTIVE_LOW>;
42			dtr-gpios = <&pioD 17 GPIO_ACTIVE_LOW>;
43			dsr-gpios = <&pioD 18 GPIO_ACTIVE_LOW>;
44			dcd-gpios = <&pioD 20 GPIO_ACTIVE_LOW>;
45			rng-gpios = <&pioD 19 GPIO_ACTIVE_LOW>;
46		};
47	
48	- use DMA:
49		usart0: serial@f001c000 {
50			compatible = "atmel,at91sam9260-usart";
51			reg = <0xf001c000 0x100>;
52			interrupts = <12 4 5>;
53			clocks = <&usart0_clk>;
54			clock-names = "usart";
55			atmel,use-dma-rx;
56			atmel,use-dma-tx;
57			dmas = <&dma0 2 0x3>,
58			       <&dma0 2 0x204>;
59			dma-names = "tx", "rx";
60		};
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