* Atmel Universal Synchronous Asynchronous Receiver/Transmitter (USART)Required properties:- compatible: Should be "atmel,<chip>-usart" The compatible <chip> indicated will be the first SoC to support an additional mode or an USART new feature.- reg: Should contain registers location and length- interrupts: Should contain interruptOptional properties:- atmel,use-dma-rx: use of PDC or DMA for receiving data- atmel,use-dma-tx: use of PDC or DMA for transmitting data<chip> compatible description:- at91rm9200: legacy USART support- at91sam9260: generic USART implementation for SAM9 SoCsExample: usart0: serial@fff8c000 { compatible = "atmel,at91sam9260-usart"; reg = <0xfff8c000 0x4000>; interrupts = <7>; atmel,use-dma-rx; atmel,use-dma-tx; };