projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 0331bbf3 NF |
1 | * Atmel Universal Synchronous Asynchronous Receiver/Transmitter (USART) |
| 2 | ||
| 3 | Required properties: | |
| 8c07f664 | 4 | - compatible: Should be "atmel,<chip>-usart" or "atmel,<chip>-dbgu" |
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5 | The compatible <chip> indicated will be the first SoC to support an |
| 6 | additional mode or an USART new feature. | |
| 8c07f664 | 7 | For the dbgu UART, use "atmel,<chip>-dbgu", "atmel,<chip>-usart" |
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8 | - reg: Should contain registers location and length |
| 9 | - interrupts: Should contain interrupt | |
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10 | - clock-names: tuple listing input clock names. |
| 11 | Required elements: "usart" | |
| 12 | - clocks: phandles to input clocks. | |
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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 | |
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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. | |
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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. | |
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25 | - atmel,fifo-size: maximum number of data the RX and TX FIFOs can store for FIFO |
| 26 | capable USARTs. | |
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27 | |
| 28 | <chip> compatible description: | |
| 29 | - at91rm9200: legacy USART support | |
| 30 | - at91sam9260: generic USART implementation for SAM9 SoCs | |
| 31 | ||
| 32 | Example: | |
| e4697193 | 33 | - use PDC: |
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34 | usart0: serial@fff8c000 { |
| 35 | compatible = "atmel,at91sam9260-usart"; | |
| 36 | reg = <0xfff8c000 0x4000>; | |
| 37 | interrupts = <7>; | |
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38 | clocks = <&usart0_clk>; |
| 39 | clock-names = "usart"; | |
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40 | atmel,use-dma-rx; |
| 41 | atmel,use-dma-tx; | |
| 7f40605a | 42 | rts-gpios = <&pioD 15 GPIO_ACTIVE_LOW>; |
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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>; | |
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48 | }; |
| 49 | ||
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50 | - use DMA: |
| 51 | usart0: serial@f001c000 { | |
| 52 | compatible = "atmel,at91sam9260-usart"; | |
| 53 | reg = <0xf001c000 0x100>; | |
| 54 | interrupts = <12 4 5>; | |
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55 | clocks = <&usart0_clk>; |
| 56 | clock-names = "usart"; | |
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57 | atmel,use-dma-rx; |
| 58 | atmel,use-dma-tx; | |
| 59 | dmas = <&dma0 2 0x3>, | |
| 60 | <&dma0 2 0x204>; | |
| 61 | dma-names = "tx", "rx"; | |
| 05a05143 | 62 | atmel,fifo-size = <32>; |
| e4697193 | 63 | }; |