From 01c38ecff8b13947f7639cb7ca9998b21c2c0ae7 Mon Sep 17 00:00:00 2001 From: Lukas Wunner Date: Mon, 18 May 2020 16:45:01 +0200 Subject: [PATCH] dt-bindings: serial: Add binding for rs485 bus termination GPIO Commit e8759ad17d41 ("serial: uapi: Add support for bus termination") introduced the ability to enable rs485 bus termination from user space. So far the feature is only used by a single driver, 8250_exar.c, using a hardcoded GPIO pin specific to Siemens IOT2040 products. Provide for a more generic solution by allowing specification of an rs485 bus termination GPIO pin in the device tree. An upcoming commit implements support for this pin for any 8250 driver. The binding is used in device trees of the "Revolution Pi" PLCs offered by KUNBUS. [Heiko Stuebner converted the binding to YAML, hence his Signed-off-by.] Signed-off-by: Heiko Stuebner Signed-off-by: Lukas Wunner Cc: Jan Kiszka Reviewed-by: Rob Herring Link: https://lore.kernel.org/r/4f4411895dc52c846f766e7f7207ec412c4811b6.1589811297.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman --- Documentation/devicetree/bindings/serial/rs485.yaml | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/Documentation/devicetree/bindings/serial/rs485.yaml b/Documentation/devicetree/bindings/serial/rs485.yaml index d4beaf11222d5..a9ad17864889c 100644 --- a/Documentation/devicetree/bindings/serial/rs485.yaml +++ b/Documentation/devicetree/bindings/serial/rs485.yaml @@ -43,3 +43,7 @@ properties: rs485-rx-during-tx: description: enables the receiving of data even while sending data. $ref: /schemas/types.yaml#/definitions/flag + + rs485-term-gpios: + description: GPIO pin to enable RS485 bus termination. + maxItems: 1 -- 2.30.2