dt-bindings: gpio: convert Atmel GPIO to json-schema

Convert the Atmel GPIO controller binding document to DT schema format
using json-schema.
The at91 pinctrl driver uses "atmel,at91rm9200-gpio" compatible string
to find the number of active GPIO banks and identify the pinmux nodes.
"atmel,at91sam9x5-gpio" and "microchip,sam9x60-gpio" have additional
registers to handle drive-strength, slew-rate,  pull-down to drive the
pinmux configs.
The new compatible string "microchip,sam9x7-gpio" is added.

Signed-off-by: Manikandan Muralidharan <manikandan.m@microchip.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20240709092354.191643-5-manikandan.m@microchip.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

Author: manikandan-m11

Documentation/devicetree/bindings/gpio/atmel,at91rm9200-gpio.yaml

@@ -0,0 +1,81 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/gpio/atmel,at91rm9200-gpio.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Microchip GPIO controller (PIO)
+
+maintainers:
+  - Manikandan Muralidharan <manikandan.m@microchip.com>
+
+properties:
+  compatible:
+    oneOf:
+      - items:
+          - enum:
+              - atmel,at91sam9x5-gpio
+              - microchip,sam9x60-gpio
+          - const: atmel,at91rm9200-gpio
+      - items:
+          - enum:
+              - microchip,sam9x7-gpio
+          - const: microchip,sam9x60-gpio
+          - const: atmel,at91rm9200-gpio
+      - items:
+          - const: atmel,at91rm9200-gpio
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  interrupt-controller: true
+
+  "#interrupt-cells":
+    const: 2
+
+  gpio-controller: true
+  gpio-line-names: true
+
+  "#gpio-cells":
+    const: 2
+
+  clocks:
+    maxItems: 1
+
+  "#gpio-lines":
+    description:
+      Number of gpio, 32 by default if absent
+    maxItems: 1
+    default: 32
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - interrupt-controller
+  - "#interrupt-cells"
+  - gpio-controller
+  - "#gpio-cells"
+  - clocks
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/at91.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    gpio@fffff400 {
+            compatible = "atmel,at91rm9200-gpio";
+            reg = <0xfffff400 0x200>;
+            interrupts = <2 IRQ_TYPE_LEVEL_HIGH 1>;
+            #gpio-cells = <2>;
+            gpio-controller;
+            interrupt-controller;
+            #interrupt-cells = <2>;
+            clocks = <&pmc PMC_TYPE_PERIPHERAL 2>;
+    };
+...