dt-bindings: gpio: Binding for MStar MSC313 GPIO controller

Add a binding description for the MStar/SigmaStar GPIO controller
found in the MSC313 and later ARMv7 SoCs.
Signed-off-by: Daniel Palmer <daniel@0x0f.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20201129110803.2461700-3-daniel@0x0f.comSigned-off-by: Linus Walleij <linus.walleij@linaro.org>

Documentation/devicetree/bindings/gpio/mstar,msc313-gpio.yaml

+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/gpio/mstar,msc313-gpio.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: MStar/SigmaStar GPIO controller
+
+maintainers:
+  - Daniel Palmer <daniel@thingy.jp>
+
+properties:
+  $nodename:
+    pattern: "^gpio@[0-9a-f]+$"
+
+  compatible:
+    const: mstar,msc313-gpio
+
+  reg:
+    maxItems: 1
+
+  gpio-controller: true
+
+  "#gpio-cells":
+    const: 2
+
+  gpio-ranges: true
+
+  interrupt-controller: true
+
+  "#interrupt-cells":
+    const: 2
+
+required:
+  - compatible
+  - reg
+  - gpio-controller
+  - "#gpio-cells"
+  - interrupt-controller
+  - "#interrupt-cells"
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/msc313-gpio.h>
+
+    gpio: gpio@207800 {
+      compatible = "mstar,msc313e-gpio";
+      #gpio-cells = <2>;
+      reg = <0x207800 0x200>;
+      gpio-controller;
+      gpio-ranges = <&pinctrl 0 36 22>,
+                    <&pinctrl 22 63 4>,
+                    <&pinctrl 26 68 6>;
+      #interrupt-cells = <2>;
+      interrupt-controller;
+      interrupt-parent = <&intc_fiq>;
+    };

MAINTAINERS

@@ -2131,6 +2131,7 @@ L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
 S:	Maintained
 W:	http://linux-chenxing.org/
 F:	Documentation/devicetree/bindings/arm/mstar/*
+F:	Documentation/devicetree/bindings/gpio/mstar,msc313-gpio.yaml
 F:	arch/arm/boot/dts/mstar-*
 F:	arch/arm/mach-mstar/
 F:	include/dt-bindings/gpio/msc313-gpio.h