mirror of
https://github.com/torvalds/linux.git
synced 2024-12-19 01:23:20 +00:00
8c07f664a6
The DBGU is not a simple UART and we need to be able to distinguish it from the other UARTs, in particular to get its address and check the chip id. Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
61 lines
2.1 KiB
Plaintext
61 lines
2.1 KiB
Plaintext
* Atmel Universal Synchronous Asynchronous Receiver/Transmitter (USART)
|
|
|
|
Required properties:
|
|
- compatible: Should be "atmel,<chip>-usart" or "atmel,<chip>-dbgu"
|
|
The compatible <chip> indicated will be the first SoC to support an
|
|
additional mode or an USART new feature.
|
|
For the dbgu UART, use "atmel,<chip>-dbgu", "atmel,<chip>-usart"
|
|
- reg: Should contain registers location and length
|
|
- interrupts: Should contain interrupt
|
|
- clock-names: tuple listing input clock names.
|
|
Required elements: "usart"
|
|
- clocks: phandles to input clocks.
|
|
|
|
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
|
|
- {rts,cts,dtr,dsr,rng,dcd}-gpios: specify a GPIO for RTS/CTS/DTR/DSR/RI/DCD line respectively.
|
|
It will use specified PIO instead of the peripheral function pin for the USART feature.
|
|
If unsure, don't specify this property.
|
|
- 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>;
|
|
clocks = <&usart0_clk>;
|
|
clock-names = "usart";
|
|
atmel,use-dma-rx;
|
|
atmel,use-dma-tx;
|
|
rts-gpios = <&pioD 15 GPIO_ACTIVE_LOW>;
|
|
cts-gpios = <&pioD 16 GPIO_ACTIVE_LOW>;
|
|
dtr-gpios = <&pioD 17 GPIO_ACTIVE_LOW>;
|
|
dsr-gpios = <&pioD 18 GPIO_ACTIVE_LOW>;
|
|
dcd-gpios = <&pioD 20 GPIO_ACTIVE_LOW>;
|
|
rng-gpios = <&pioD 19 GPIO_ACTIVE_LOW>;
|
|
};
|
|
|
|
- use DMA:
|
|
usart0: serial@f001c000 {
|
|
compatible = "atmel,at91sam9260-usart";
|
|
reg = <0xf001c000 0x100>;
|
|
interrupts = <12 4 5>;
|
|
clocks = <&usart0_clk>;
|
|
clock-names = "usart";
|
|
atmel,use-dma-rx;
|
|
atmel,use-dma-tx;
|
|
dmas = <&dma0 2 0x3>,
|
|
<&dma0 2 0x204>;
|
|
dma-names = "tx", "rx";
|
|
};
|