From 0331bbf3c6fd9997e5f0d165840229ccfeba6548 Mon Sep 17 00:00:00 2001 From: Nicolas Ferre Date: Wed, 12 Oct 2011 18:06:56 +0200 Subject: tty/serial: RS485 bindings for device tree Generic bindings for RS485 feature included in some UARTs. Those bindings have to be used withing an UART device tree node. Documentation updated to link to the bindings definition. Signed-off-by: Nicolas Ferre Acked-by: Grant Likely Signed-off-by: Greg Kroah-Hartman --- Documentation/devicetree/bindings/serial/rs485.txt | 31 ++++++++++++++++++++++ 1 file changed, 31 insertions(+) create mode 100644 Documentation/devicetree/bindings/serial/rs485.txt (limited to 'Documentation/devicetree/bindings/serial') diff --git a/Documentation/devicetree/bindings/serial/rs485.txt b/Documentation/devicetree/bindings/serial/rs485.txt new file mode 100644 index 000000000000..1e753c69fc83 --- /dev/null +++ b/Documentation/devicetree/bindings/serial/rs485.txt @@ -0,0 +1,31 @@ +* RS485 serial communications + +The RTS signal is capable of automatically controlling line direction for +the built-in half-duplex mode. +The properties described hereafter shall be given to a half-duplex capable +UART node. + +Required properties: +- rs485-rts-delay: prop-encoded-array where: + * a is the delay beteween rts signal and beginning of data sent in milliseconds. + it corresponds to the delay before sending data. + * b is the delay between end of data sent and rts signal in milliseconds + it corresponds to the delay after sending data and actual release of the line. + +Optional properties: +- linux,rs485-enabled-at-boot-time: empty property telling to enable the rs485 + feature at boot time. It can be disabled later with proper ioctl. +- rs485-rx-during-tx: empty property that enables the receiving of data even + whilst sending data. + +RS485 example for Atmel USART: + usart0: serial@fff8c000 { + compatible = "atmel,at91sam9260-usart"; + reg = <0xfff8c000 0x4000>; + interrupts = <7>; + atmel,use-dma-rx; + atmel,use-dma-tx; + linux,rs485-enabled-at-boot-time; + rs485-rts-delay = <0 200>; // in milliseconds + }; + -- cgit v1.2.1