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Based on kernel version 4.7.2. Page generated on 2016-08-22 22:43 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	- atmel,fifo-size: maximum number of data the RX and TX FIFOs can store for FIFO
26	  capable USARTs.
27	
28	<chip> compatible description:
29	- at91rm9200:  legacy USART support
30	- at91sam9260: generic USART implementation for SAM9 SoCs
31	
32	Example:
33	- use PDC:
34		usart0: serial@fff8c000 {
35			compatible = "atmel,at91sam9260-usart";
36			reg = <0xfff8c000 0x4000>;
37			interrupts = <7>;
38			clocks = <&usart0_clk>;
39			clock-names = "usart";
40			atmel,use-dma-rx;
41			atmel,use-dma-tx;
42			rts-gpios = <&pioD 15 GPIO_ACTIVE_LOW>;
43			cts-gpios = <&pioD 16 GPIO_ACTIVE_LOW>;
44			dtr-gpios = <&pioD 17 GPIO_ACTIVE_LOW>;
45			dsr-gpios = <&pioD 18 GPIO_ACTIVE_LOW>;
46			dcd-gpios = <&pioD 20 GPIO_ACTIVE_LOW>;
47			rng-gpios = <&pioD 19 GPIO_ACTIVE_LOW>;
48		};
49	
50	- use DMA:
51		usart0: serial@f001c000 {
52			compatible = "atmel,at91sam9260-usart";
53			reg = <0xf001c000 0x100>;
54			interrupts = <12 4 5>;
55			clocks = <&usart0_clk>;
56			clock-names = "usart";
57			atmel,use-dma-rx;
58			atmel,use-dma-tx;
59			dmas = <&dma0 2 0x3>,
60			       <&dma0 2 0x204>;
61			dma-names = "tx", "rx";
62			atmel,fifo-size = <32>;
63		};
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