dt-bindings: interrupt-controller: Add Qualcomm MPM support

It adds DT binding support for Qualcomm MPM interrupt controller.
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220308080534.3384532-2-shawn.guo@linaro.org

Documentation/devicetree/bindings/interrupt-controller/qcom,mpm.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/interrupt-controller/qcom,mpm.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Qualcom MPM Interrupt Controller
+
+maintainers:
+  - Shawn Guo <shawn.guo@linaro.org>
+
+description:
+  Qualcomm Technologies Inc. SoCs based on the RPM architecture have a
+  MSM Power Manager (MPM) that is in always-on domain. In addition to managing
+  resources during sleep, the hardware also has an interrupt controller that
+  monitors the interrupts when the system is asleep, wakes up the APSS when
+  one of these interrupts occur and replays it to GIC interrupt controller
+  after GIC becomes operational.
+
+allOf:
+  - $ref: /schemas/interrupt-controller.yaml#
+
+properties:
+  compatible:
+    items:
+      - const: qcom,mpm
+
+  reg:
+    maxItems: 1
+    description:
+      Specifies the base address and size of vMPM registers in RPM MSG RAM.
+
+  interrupts:
+    maxItems: 1
+    description:
+      Specify the IRQ used by RPM to wakeup APSS.
+
+  mboxes:
+    maxItems: 1
+    description:
+      Specify the mailbox used to notify RPM for writing vMPM registers.
+
+  interrupt-controller: true
+
+  '#interrupt-cells':
+    const: 2
+    description:
+      The first cell is the MPM pin number for the interrupt, and the second
+      is the trigger type.
+
+  qcom,mpm-pin-count:
+    description:
+      Specify the total MPM pin count that a SoC supports.
+    $ref: /schemas/types.yaml#/definitions/uint32
+
+  qcom,mpm-pin-map:
+    description:
+      A set of MPM pin numbers and the corresponding GIC SPIs.
+    $ref: /schemas/types.yaml#/definitions/uint32-matrix
+    items:
+      items:
+        - description: MPM pin number
+        - description: GIC SPI number for the MPM pin
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - mboxes
+  - interrupt-controller
+  - '#interrupt-cells'
+  - qcom,mpm-pin-count
+  - qcom,mpm-pin-map
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    mpm: interrupt-controller@45f01b8 {
+        compatible = "qcom,mpm";
+        interrupts = <GIC_SPI 197 IRQ_TYPE_EDGE_RISING>;
+        reg = <0x45f01b8 0x1000>;
+        mboxes = <&apcs_glb 1>;
+        interrupt-controller;
+        #interrupt-cells = <2>;
+        interrupt-parent = <&intc>;
+        qcom,mpm-pin-count = <96>;
+        qcom,mpm-pin-map = <2 275>,
+                           <5 296>,
+                           <12 422>,
+                           <24 79>,
+                           <86 183>,
+                           <90 260>,
+                           <91 260>;
+    };