dt-bindings: serial: max310x: convert to YAML

Convert binding from text format to YAML.

Additions to original text binding:
- add rs485 reference.

Signed-off-by: Hugo Villeneuve <[e-mail]>
Reviewed-by: Krzysztof Kozlowski <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

Documentation/devicetree/bindings/serial/maxim,max310x.txt

···
-* Maxim MAX310X advanced Universal Asynchronous Receiver-Transmitter (UART)
-
-Required properties:
-- compatible: Should be one of the following:
-  - "maxim,max3107" for Maxim MAX3107,
-  - "maxim,max3108" for Maxim MAX3108,
-  - "maxim,max3109" for Maxim MAX3109,
-  - "maxim,max14830" for Maxim MAX14830.
-- reg: SPI chip select number.
-- interrupts: Specifies the interrupt source of the parent interrupt
-  controller. The format of the interrupt specifier depends on the
-  parent interrupt controller.
-- clocks: phandle to the IC source clock.
-- clock-names: Should be "xtal" if clock is an external crystal or
-  "osc" if an external clock source is used.
-
-Optional properties:
-- gpio-controller: Marks the device node as a GPIO controller.
-- #gpio-cells: Should be two. The first cell is the GPIO number and
-  the second cell is used to specify the GPIO polarity:
-    0 = active high,
-    1 = active low.
-
-Example:
-
-/ {
-	clocks {
-		spi_uart_clk: osc_max14830 {
-			compatible = "fixed-clock";
-			#clock-cells = <0>;
-			clock-frequency = <3686400>;
-		};
-
-	};
-};
-
-&spi0 {
-	max14830: max14830@0 {
-		compatible = "maxim,max14830";
-		reg = <0>;
-		clocks = <&spi_uart_clk>;
-		clock-names = "osc";
-		interrupt-parent = <&gpio3>;
-		interrupts = <7 IRQ_TYPE_LEVEL_LOW>;
-		gpio-controller;
-		#gpio-cells = <2>;
-	};
-};

Documentation/devicetree/bindings/serial/maxim,max310x.yaml

···
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/serial/maxim,max310x.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Maxim MAX310X Advanced Universal Asynchronous Receiver-Transmitter (UART)
+
+maintainers:
+  - Hugo Villeneuve <[e-mail]>
+
+properties:
+  compatible:
+    enum:
+      - maxim,max3107
+      - maxim,max3108
+      - maxim,max3109
+      - maxim,max14830
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  clock-names:
+    enum:
+      - xtal # External crystal
+      - osc  # External clock source
+
+  gpio-controller: true
+
+  "#gpio-cells":
+    const: 2
+
+  gpio-line-names:
+    minItems: 1
+    maxItems: 16
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - clocks
+  - clock-names
+
+allOf:
+  - $ref: /schemas/spi/spi-peripheral-props.yaml#
+  - $ref: /schemas/serial/serial.yaml#
+  - $ref: /schemas/serial/rs485.yaml#
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        serial@2c {
+            compatible = "maxim,max3107";
+            reg = <0x2c>;
+            clocks = <&xtal4m>;
+            clock-names = "xtal";
+            interrupt-parent = <&gpio3>;
+            interrupts = <7 IRQ_TYPE_LEVEL_LOW>;
+            gpio-controller;
+            #gpio-cells = <2>;
+        };
+    };