projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 0331bbf3 NF |
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 | |
| 8be3da65 BB |
9 | - clock-names: tuple listing input clock names. |
| 10 | Required elements: "usart" | |
| 11 | - clocks: phandles to input clocks. | |
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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 | |
| e0b0baad RG |
16 | - {rts,cts,dtr,dsr,rng,dcd}-gpios: specify a GPIO for RTS/CTS/DTR/DSR/RI/DCD line respectively. |
| 17 | It will use specified PIO instead of the peripheral function pin for the USART feature. | |
| 18 | If unsure, don't specify this property. | |
| e4697193 ES |
19 | - add dma bindings for dma transfer: |
| 20 | - dmas: DMA specifier, consisting of a phandle to DMA controller node, | |
| 21 | memory peripheral interface and USART DMA channel ID, FIFO configuration. | |
| 22 | Refer to dma.txt and atmel-dma.txt for details. | |
| 23 | - dma-names: "rx" for RX channel, "tx" for TX channel. | |
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24 | |
| 25 | <chip> compatible description: | |
| 26 | - at91rm9200: legacy USART support | |
| 27 | - at91sam9260: generic USART implementation for SAM9 SoCs | |
| 28 | ||
| 29 | Example: | |
| e4697193 | 30 | - use PDC: |
| 0331bbf3 NF |
31 | usart0: serial@fff8c000 { |
| 32 | compatible = "atmel,at91sam9260-usart"; | |
| 33 | reg = <0xfff8c000 0x4000>; | |
| 34 | interrupts = <7>; | |
| 8be3da65 BB |
35 | clocks = <&usart0_clk>; |
| 36 | clock-names = "usart"; | |
| 0331bbf3 NF |
37 | atmel,use-dma-rx; |
| 38 | atmel,use-dma-tx; | |
| 7f40605a | 39 | rts-gpios = <&pioD 15 GPIO_ACTIVE_LOW>; |
| e0b0baad RG |
40 | cts-gpios = <&pioD 16 GPIO_ACTIVE_LOW>; |
| 41 | dtr-gpios = <&pioD 17 GPIO_ACTIVE_LOW>; | |
| 42 | dsr-gpios = <&pioD 18 GPIO_ACTIVE_LOW>; | |
| 43 | dcd-gpios = <&pioD 20 GPIO_ACTIVE_LOW>; | |
| 44 | rng-gpios = <&pioD 19 GPIO_ACTIVE_LOW>; | |
| 0331bbf3 NF |
45 | }; |
| 46 | ||
| e4697193 ES |
47 | - use DMA: |
| 48 | usart0: serial@f001c000 { | |
| 49 | compatible = "atmel,at91sam9260-usart"; | |
| 50 | reg = <0xf001c000 0x100>; | |
| 51 | interrupts = <12 4 5>; | |
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52 | clocks = <&usart0_clk>; |
| 53 | clock-names = "usart"; | |
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54 | atmel,use-dma-rx; |
| 55 | atmel,use-dma-tx; | |
| 56 | dmas = <&dma0 2 0x3>, | |
| 57 | <&dma0 2 0x204>; | |
| 58 | dma-names = "tx", "rx"; | |
| 59 | }; |