dt-bindings: soc: qcom,smp2p: convert to dtschema

Convert the Qualcomm Shared Memory Point 2 Point bindings to DT Schema.

Changes against original bindings: enforce only specific names of child
nodes, instead of any names.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220411155528.502889-1-krzysztof.kozlowski@linaro.org

Author: krzk

Documentation/devicetree/bindings/soc/qcom/qcom,smp2p.txt

@@ -0,0 +1,145 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/soc/qcom/qcom,smp2p.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Qualcomm Shared Memory Point 2 Point
+
+maintainers:
+  - Andy Gross <agross@kernel.org>
+  - Bjorn Andersson <bjorn.andersson@linaro.org>
+  - Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
+
+description:
+  The Shared Memory Point to Point (SMP2P) protocol facilitates communication
+  of a single 32-bit value between two processors.  Each value has a single
+  writer (the local side) and a single reader (the remote side).  Values are
+  uniquely identified in the system by the directed edge (local processor ID to
+  remote processor ID) and a string identifier.
+
+properties:
+  compatible:
+    const: qcom,smp2p
+
+  interrupts:
+    maxItems: 1
+
+  mboxes:
+    maxItems: 1
+    description:
+      Reference to the mailbox representing the outgoing doorbell in APCS for
+      this client.
+
+  qcom,ipc:
+    $ref: /schemas/types.yaml#/definitions/phandle-array
+    items:
+      - items:
+          - description: phandle to a syscon node representing the APCS registers
+          - description: u32 representing offset to the register within the syscon
+          - description: u32 representing the ipc bit within the register
+    description:
+      Three entries specifying the outgoing ipc bit used for signaling the
+      remote end of the smp2p edge.
+
+  qcom,local-pid:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description:
+      The identifier of the local endpoint of this edge.
+
+  qcom,remote-pid:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description:
+      The identifier of the remote endpoint of this edge.
+
+  qcom,smem:
+    $ref: /schemas/types.yaml#/definitions/uint32-array
+    items:
+      maxItems: 2
+    description:
+      Two identifiers of the inbound and outbound smem items used for this edge.
+
+patternProperties:
+  "^master-kernel|slave-kernel|ipa-ap-to-modem|ipa-modem-to-ap$":
+    type: object
+    description:
+      Each SMP2P pair contain a set of inbound and outbound entries, these are
+      described in subnodes of the smp2p device node. The node names are not
+      important.
+
+    properties:
+      interrupt-controller:
+        description:
+          Marks the entry as inbound; the node should be specified as a two
+          cell interrupt-controller.  If not specified this node will denote
+          the outgoing entry.
+
+      '#interrupt-cells':
+        const: 2
+
+      qcom,entry-name:
+        $ref: /schemas/types.yaml#/definitions/string
+        description:
+          The name of this entry, for inbound entries this will be used to
+          match against the remotely allocated entry and for outbound entries
+          this name is used for allocating entries.
+
+      '#qcom,smem-state-cells':
+        $ref: /schemas/types.yaml#/definitions/uint32
+        const: 1
+        description:
+          Required for outgoing entries.
+
+    required:
+      - qcom,entry-name
+
+    oneOf:
+      - required:
+          - interrupt-controller
+          - '#interrupt-cells'
+      - required:
+          - '#qcom,smem-state-cells'
+
+    additionalProperties: false
+
+required:
+  - compatible
+  - interrupts
+  - qcom,local-pid
+  - qcom,remote-pid
+  - qcom,smem
+
+oneOf:
+  - required:
+      - mboxes
+  - required:
+      - qcom,ipc
+
+additionalProperties: false
+
+examples:
+  # The following example shows the SMP2P setup with the wireless processor,
+  # defined from the 8974 apps processor's point-of-view. It encompasses one
+  # inbound and one outbound entry.
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+
+    shared-memory {
+        compatible = "qcom,smp2p";
+        qcom,smem = <431>, <451>;
+        interrupts = <GIC_SPI 143 IRQ_TYPE_EDGE_RISING>;
+        qcom,ipc = <&apcs 8 18>;
+        qcom,local-pid = <0>;
+        qcom,remote-pid = <4>;
+
+        wcnss_smp2p_out: master-kernel {
+            qcom,entry-name = "master-kernel";
+            #qcom,smem-state-cells = <1>;
+        };
+
+        wcnss_smp2p_in: slave-kernel {
+            qcom,entry-name = "slave-kernel";
+            interrupt-controller;
+            #interrupt-cells = <2>;
+        };
+    };