dt-bindings: serial: Convert STM32 UART to json-schema

Convert STM32 UART bindings to json-schema.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@st.com>
Signed-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/serial/st,stm32-uart.yaml

@@ -0,0 +1,80 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/serial/st,stm32-uart.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+maintainers:
+  - Erwan Le Ray <erwan.leray@st.com>
+
+title: STMicroelectronics STM32 USART bindings
+
+allOf:
+  - $ref: rs485.yaml
+
+properties:
+  compatible:
+    enum:
+      - st,stm32-uart
+      - st,stm32f7-uart
+      - st,stm32h7-uart
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  resets:
+    maxItems: 1
+
+  label:
+    description: label associated with this uart
+
+  st,hw-flow-ctrl:
+    description: enable hardware flow control
+    $ref: /schemas/types.yaml#/definitions/flag
+
+  dmas:
+    minItems: 1
+    maxItems: 2
+
+  dma-names:
+    items:
+      enum: [ rx, tx ]
+    minItems: 1
+    maxItems: 2
+
+  wakeup-source: true
+
+  rs485-rts-delay: true
+  rs485-rts-active-low: true
+  linux,rs485-enabled-at-boot-time: true
+  rs485-rx-during-tx: true
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - clocks
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/stm32mp1-clks.h>
+    usart1: serial@40011000 {
+      compatible = "st,stm32-uart";
+      reg = <0x40011000 0x400>;
+      interrupts = <37>;
+      clocks = <&rcc 0 164>;
+      dmas = <&dma2 2 4 0x414 0x0>,
+             <&dma2 7 4 0x414 0x0>;
+      dma-names = "rx", "tx";
+      rs485-rts-active-low;
+    };
+
+...