1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
|
* 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 interrupt
Optional 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
- add dma bindings for dma transfer:
- dmas: DMA specifier, consisting of a phandle to DMA controller node,
memory peripheral interface and USART DMA channel ID, FIFO configuration.
Refer to dma.txt and atmel-dma.txt for details.
- dma-names: "rx" for RX channel, "tx" for TX channel.
<chip> compatible description:
- at91rm9200: legacy USART support
- at91sam9260: generic USART implementation for SAM9 SoCs
Example:
- use PDC:
usart0: serial@fff8c000 {
compatible = "atmel,at91sam9260-usart";
reg = <0xfff8c000 0x4000>;
interrupts = <7>;
atmel,use-dma-rx;
atmel,use-dma-tx;
};
- use DMA:
usart0: serial@f001c000 {
compatible = "atmel,at91sam9260-usart";
reg = <0xf001c000 0x100>;
interrupts = <12 4 5>;
atmel,use-dma-rx;
atmel,use-dma-tx;
dmas = <&dma0 2 0x3>,
<&dma0 2 0x204>;
dma-names = "tx", "rx";
};
|
