dt-bindings: mfd: Add Apple Mac System Management Controller

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

Signed-off-by: "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Reviewed-by: Neal Gompa <neal@gompa.dev>
Signed-off-by: Sven Peter <sven@kernel.org>
Link: https://lore.kernel.org/r/20250610-smc-6-15-v7-3-556cafd771d3@kernel.org
Signed-off-by: Lee Jones <lee@kernel.org>

Documentation/devicetree/bindings/mfd/apple,smc.yaml

@@ -0,0 +1,79 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mfd/apple,smc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Apple Mac System Management Controller
+
+maintainers:
+  - Sven Peter <sven@kernel.org>
+
+description:
+  Apple Mac System Management Controller implements various functions
+  such as GPIO, RTC, power, reboot.
+
+properties:
+  compatible:
+    items:
+      - enum:
+          - apple,t6000-smc
+          - apple,t8103-smc
+          - apple,t8112-smc
+      - const: apple,smc
+
+  reg:
+    items:
+      - description: SMC area
+      - description: SRAM area
+
+  reg-names:
+    items:
+      - const: smc
+      - const: sram
+
+  mboxes:
+    maxItems: 1
+
+  gpio:
+    $ref: /schemas/gpio/apple,smc-gpio.yaml
+
+  reboot:
+    $ref: /schemas/power/reset/apple,smc-reboot.yaml
+
+additionalProperties: false
+
+required:
+  - compatible
+  - reg
+  - reg-names
+  - mboxes
+
+examples:
+  - |
+    soc {
+      #address-cells = <2>;
+      #size-cells = <2>;
+
+      smc@23e400000 {
+        compatible = "apple,t8103-smc", "apple,smc";
+        reg = <0x2 0x3e400000 0x0 0x4000>,
+               <0x2 0x3fe00000 0x0 0x100000>;
+        reg-names = "smc", "sram";
+        mboxes = <&smc_mbox>;
+
+        smc_gpio: gpio {
+          compatible = "apple,smc-gpio";
+          gpio-controller;
+          #gpio-cells = <2>;
+        };
+
+        reboot {
+          compatible = "apple,smc-reboot";
+          nvmem-cells = <&shutdown_flag>, <&boot_stage>,
+                        <&boot_error_count>, <&panic_count>;
+          nvmem-cell-names = "shutdown_flag", "boot_stage",
+                             "boot_error_count", "panic_count";
+        };
+      };
+    };

MAINTAINERS

@@ -2339,6 +2339,7 @@ F:	Documentation/devicetree/bindings/iommu/apple,dart.yaml
 F:	Documentation/devicetree/bindings/iommu/apple,sart.yaml
 F:	Documentation/devicetree/bindings/leds/backlight/apple,dwi-bl.yaml
 F:	Documentation/devicetree/bindings/mailbox/apple,mailbox.yaml
+F:	Documentation/devicetree/bindings/mfd/apple,smc.yaml
 F:	Documentation/devicetree/bindings/net/bluetooth/brcm,bcm4377-bluetooth.yaml
 F:	Documentation/devicetree/bindings/nvme/apple,nvme-ans.yaml
 F:	Documentation/devicetree/bindings/nvmem/apple,efuses.yaml