Documentation/devicetree/bindings/serial/atmel-usart.txt

   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 - add dma bindings for dma transfer:
  17         - dmas: DMA specifier, consisting of a phandle to DMA controller node,
  18                 memory peripheral interface and USART DMA channel ID, FIFO configuration.
  19                 Refer to dma.txt and atmel-dma.txt for details.
  20         - dma-names: "rx" for RX channel, "tx" for TX channel.
  21
  22 <chip> compatible description:
  23 - at91rm9200:  legacy USART support
  24 - at91sam9260: generic USART implementation for SAM9 SoCs
  25
  26 Example:
  27 - use PDC:
  28         usart0: serial@fff8c000 {
  29                 compatible = "atmel,at91sam9260-usart";
  30                 reg = <0xfff8c000 0x4000>;
  31                 interrupts = <7>;
  32                 clocks = <&usart0_clk>;
  33                 clock-names = "usart";
  34                 atmel,use-dma-rx;
  35                 atmel,use-dma-tx;
  36         };
  37
  38 - use DMA:
  39         usart0: serial@f001c000 {
  40                 compatible = "atmel,at91sam9260-usart";
  41                 reg = <0xf001c000 0x100>;
  42                 interrupts = <12 4 5>;
  43                 clocks = <&usart0_clk>;
  44                 clock-names = "usart";
  45                 atmel,use-dma-rx;
  46                 atmel,use-dma-tx;
  47                 dmas = <&dma0 2 0x3>,
  48                        <&dma0 2 0x204>;
  49                 dma-names = "tx", "rx";
  50         };