spi: dt-bindings: apple,spi: Add binding for Apple SPI controllers

The Apple SPI controller is present in SoCs such as the M1 (t8103) and
M1 Pro/Max (t600x). This controller uses one IRQ and one clock, and
doesn't need any special properties, so the binding is trivial.

Signed-off-by: Hector Martin <marcan@marcan.st>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Nick Chan <towinchenmi@gmail.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Janne Grunau <j@jannau.net>
Reviewed-by: Mark Kettenis <kettenis@openbsd.org>
Link: https://patch.msgid.link/20241106-asahi-spi-v5-1-e81a4f3a8e19@jannau.net
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: marcan

Documentation/devicetree/bindings/spi/apple,spi.yaml

@@ -0,0 +1,62 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/spi/apple,spi.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Apple ARM SoC SPI controller
+
+allOf:
+  - $ref: spi-controller.yaml#
+
+maintainers:
+  - Hector Martin <marcan@marcan.st>
+
+properties:
+  compatible:
+    items:
+      - enum:
+          - apple,t8103-spi
+          - apple,t8112-spi
+          - apple,t6000-spi
+      - const: apple,spi
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  power-domains:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - interrupts
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/apple-aic.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    soc {
+      #address-cells = <2>;
+      #size-cells = <2>;
+
+      spi@39b104000 {
+        compatible = "apple,t6000-spi", "apple,spi";
+        reg = <0x3 0x9b104000 0x0 0x4000>;
+        interrupt-parent = <&aic>;
+        interrupts = <AIC_IRQ 0 1107 IRQ_TYPE_LEVEL_HIGH>;
+        #address-cells = <1>;
+        #size-cells = <0>;
+        clocks = <&clk>;
+      };
+    };