dt-bindings: gpio: Add Apple Mac SMC GPIO block

Add the DT binding for the Apple Mac System Management Controller GPIOs.

Signed-off-by: "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Reviewed-by: Neal Gompa <neal@gompa.dev>
Reviewed-by: "Rob Herring (Arm)" <robh@kernel.org>
Signed-off-by: Sven Peter <sven@kernel.org>
Link: https://lore.kernel.org/r/20250610-smc-6-15-v7-1-556cafd771d3@kernel.org
Signed-off-by: Lee Jones <lee@kernel.org>

Author: Russell King (Oracle)

Documentation/devicetree/bindings/gpio/apple,smc-gpio.yaml

@@ -0,0 +1,29 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/gpio/apple,smc-gpio.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Apple Mac System Management Controller GPIO
+
+maintainers:
+  - Sven Peter <sven@kernel.org>
+
+description:
+  Apple Mac System Management Controller GPIO block.
+
+properties:
+  compatible:
+    const: apple,smc-gpio
+
+  gpio-controller: true
+
+  '#gpio-cells':
+    const: 2
+
+required:
+  - compatible
+  - gpio-controller
+  - '#gpio-cells'
+
+additionalProperties: false

MAINTAINERS

@@ -2331,6 +2331,7 @@ F:	Documentation/devicetree/bindings/arm/apple/*
 F:	Documentation/devicetree/bindings/clock/apple,nco.yaml
 F:	Documentation/devicetree/bindings/cpufreq/apple,cluster-cpufreq.yaml
 F:	Documentation/devicetree/bindings/dma/apple,admac.yaml
+F:	Documentation/devicetree/bindings/gpio/apple,smc-gpio.yaml
 F:	Documentation/devicetree/bindings/i2c/apple,i2c.yaml
 F:	Documentation/devicetree/bindings/input/touchscreen/apple,z2-multitouch.yaml
 F:	Documentation/devicetree/bindings/interrupt-controller/apple,*