dt-bindings: serial: Convert rs485 bindings to json-schema

Convert rs485 binding to yaml style file.
Signed-off-by: Benjamin Gaignard <benjamin.gaignard@st.com>
Signed-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/serial/rs485.txt

-* 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.
-
-Optional properties:
-- rs485-rts-delay: prop-encoded-array <a b> where:
-  * a is the delay between 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.
-  If this property is not specified, <0 0> is assumed.
-- rs485-rts-active-low: drive RTS low when sending (default is high).
-- 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
-  while 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
-	};
-
+See rs485.yaml

Documentation/devicetree/bindings/serial/rs485.yaml

+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/serial/rs485.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: RS485 serial communications Bindings
+
+description: 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.
+
+maintainers:
+  -  Rob Herring <robh@kernel.org>
+
+properties:
+  rs485-rts-delay:
+    description: prop-encoded-array <a b>
+    allOf:
+      - $ref: /schemas/types.yaml#/definitions/uint32-array
+      - items:
+          items:
+            - description:
+                Delay between rts signal and beginning of data sent in milliseconds.
+                It corresponds to the delay before sending data.
+              default: 0
+              maximum: 1000
+            - description:
+                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.
+              default: 0
+              maximum: 1000
+
+  rs485-rts-active-low:
+    description: drive RTS low when sending (default is high).
+    $ref: /schemas/types.yaml#/definitions/flag
+
+  linux,rs485-enabled-at-boot-time:
+    description: enables the rs485 feature at boot time. It can be disabled later with proper ioctl.
+    $ref: /schemas/types.yaml#/definitions/flag
+
+  rs485-rx-during-tx:
+   description: enables the receiving of data even while sending data.
+   $ref: /schemas/types.yaml#/definitions/flag