dt-bindings: Add devicetree bindings

Add snapshot of device tree bindings from keystone common kernel, branch
"android-mainline-keystone-qcom-release" at c4c12103f9c0 ("Snap for 9228065
from e32903b9a63bb558df8b803b076619c53c16baad to
android-mainline-keystone-qcom-release").

Change-Id: I7682079615cbd9f29340a5c1f2a1d84ec441a1f1
Signed-off-by: Melody Olvera <quic_molvera@quicinc.com>

bindings/interrupt-controller/msi-controller.yaml

@@ -0,0 +1,46 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/interrupt-controller/msi-controller.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: MSI controller
+
+maintainers:
+  - Marc Zyngier <maz@kernel.org>
+
+description: |
+  An MSI controller signals interrupts to a CPU when a write is made
+  to an MMIO address by some master. An MSI controller may feature a
+  number of doorbells.
+
+properties:
+  "#msi-cells":
+    description: |
+      The number of cells in an msi-specifier, required if not zero.
+
+      Typically this will encode information related to sideband data,
+      and will not encode doorbells or payloads as these can be
+      configured dynamically.
+
+      The meaning of the msi-specifier is defined by the device tree
+      binding of the specific MSI controller.
+    enum: [0, 1]
+
+  msi-controller:
+    description:
+      Identifies the node as an MSI controller.
+    $ref: /schemas/types.yaml#/definitions/flag
+
+  msi-ranges:
+    description:
+      A list of <phandle intspec span> tuples, where "phandle" is the
+      parent interrupt controller, "intspec" is the starting/base
+      interrupt specifier and "span" is the size of the
+      range. Multiple ranges can be provided.
+    $ref: /schemas/types.yaml#/definitions/phandle-array
+
+dependencies:
+  "#msi-cells": [ msi-controller ]
+
+additionalProperties: true