[PATCH v4 2/2] dt-bindings: serial: Add support for enabling RS485 mode via GPIO at boot time

["Tomas Paukrt" <tomaspaukrt@xxxxxxxx>]

Add an option to enable the RS485 mode at boot time based on
the state of a GPIO pin (DIP switch or configuration jumper).
The GPIO is defined by the device tree property "linux,rs485-mode-gpio".

Signed-off-by: Tomas Paukrt <tomaspaukrt@xxxxxxxx>
---
 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 9418fd6..7a72f37 100644
--- a/Documentation/devicetree/bindings/serial/rs485.yaml
+++ b/Documentation/devicetree/bindings/serial/rs485.yaml
@@ -47,6 +47,10 @@ properties:
       later with proper ioctl.
     $ref: /schemas/types.yaml#/definitions/flag
 
+  linux,rs485-mode-gpio:
+    description: GPIO pin to enable RS485 mode at boot time.
+    maxItems: 1
+
   rs485-rx-during-tx:
     description: enables the receiving of data even while sending data.
     $ref: /schemas/types.yaml#/definitions/flag
-- 
2.7.4