dt-bindings: perf: Convert Arm DSU to schema

Convert the DSU binding to schema, as one does.
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/9fde2e11b0d11285c26d0e9d261034a1628c7901.1639490264.git.robin.murphy@arm.comSigned-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/arm/arm-dsu-pmu.txt

-* ARM DynamIQ Shared Unit (DSU) Performance Monitor Unit (PMU)
-
-ARM DyanmIQ Shared Unit (DSU) integrates one or more CPU cores
-with a shared L3 memory system, control logic and external interfaces to
-form a multicore cluster. The PMU enables to gather various statistics on
-the operations of the DSU. The PMU provides independent 32bit counters that
-can count any of the supported events, along with a 64bit cycle counter.
-The PMU is accessed via CPU system registers and has no MMIO component.
-
-** DSU PMU required properties:
-
-- compatible	: should be one of :
-
-		"arm,dsu-pmu"
-
-- interrupts	: Exactly 1 SPI must be listed.
-
-- cpus		: List of phandles for the CPUs connected to this DSU instance.
-
-
-** Example:
-
-dsu-pmu-0 {
-	compatible = "arm,dsu-pmu";
-	interrupts = <GIC_SPI 02 IRQ_TYPE_LEVEL_HIGH>;
-	cpus = <&cpu_0>, <&cpu_1>;
-};

Documentation/devicetree/bindings/perf/arm,dsu-pmu.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+# Copyright 2021 Arm Ltd.
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/perf/arm,dsu-pmu.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ARM DynamIQ Shared Unit (DSU) Performance Monitor Unit (PMU)
+
+maintainers:
+  - Suzuki K Poulose <suzuki.poulose@arm.com>
+  - Robin Murphy <robin.murphy@arm.com>
+
+description:
+  ARM DynamIQ Shared Unit (DSU) integrates one or more CPU cores with a shared
+  L3 memory system, control logic and external interfaces to form a multicore
+  cluster. The PMU enables gathering various statistics on the operation of the
+  DSU. The PMU provides independent 32-bit counters that can count any of the
+  supported events, along with a 64-bit cycle counter. The PMU is accessed via
+  CPU system registers and has no MMIO component.
+
+properties:
+  compatible:
+    const: arm,dsu-pmu
+
+  interrupts:
+    items:
+      - description: nCLUSTERPMUIRQ interrupt
+
+  cpus:
+    $ref: /schemas/types.yaml#/definitions/phandle-array
+    minItems: 1
+    maxItems: 8
+    description: List of phandles for the CPUs connected to this DSU instance.
+
+required:
+  - compatible
+  - interrupts
+  - cpus
+
+additionalProperties: false