dt-bindings: soc: qcom: Add bindings for smp2p sleepstate driver

Add the bindings for the smp2p sleepstate driver in YAML.

Smp2p sleepstate driver unset the SMP2P PROC_AWAKE_ID bit if Apps
is going into suspend, set it again when Apps comes out of suspend.

By reading this SMP2P bit, the remote side knows when to avoid
sending data.

Change-Id: I5ad0a431a6c9a40d2a08e9f6a864956b49e0aeab
Signed-off-by: leihan <quic_leihan@quicinc.com>

bindings/soc/qcom/sleepstate-smp2p.yaml

@@ -0,0 +1,60 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/soc/qcom/sleepstate-smp2p.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: SMSM Point-to-Point (SMP2P) Sleepstate driver
+
+maintainers:
+  - Lei Han <quic_leihan@quicinc.com>
+
+description: |
+  The SMP2P Sleepstate driver advertises (over SMP2P) whether
+  or not the Apps processor is in suspend. By reading this SMP2P
+  bit, the remote side can tell whether or not Apps is in
+  suspend, and thus know when to avoid sending data.
+
+properties:
+  compatible:
+    const: qcom,smp2p-sleepstate
+
+  qcom,smem-states:
+    $ref: '/schemas/types.yaml#/definitions/phandle-array'
+    description:
+      States used by the Apps to signal remote side about
+      suspend transitions.
+    items:
+      - description:
+          Represent Apps is going into suspend by unsetting the
+          SMP2P PROC_AWAKE_ID bit of Apps; notify remote processor
+          stop sending data.
+
+  interrupts:
+    maxItems: 1
+    description:
+      The interrupt number, the irq line to be used.
+
+  interrupt-names:
+    items:
+      - const: smp2p-sleepstate-in
+    description:
+      Interrupt name string.
+
+required:
+  - compatible
+  - qcom,smem-states
+  - interrupts
+  - interrupt-names
+
+additionalProperties: false
+
+examples:
+  - |
+    qcom,smp2p_sleepstate {
+        compatible = "qcom,smp2p-sleepstate";
+        qcom,smem-states = <&sleepstate_smp2p_out 0>;
+        interrupt-parent = <&sleepstate_smp2p_in>;
+        interrupts = <0 0>;
+        interrupt-names = "smp2p-sleepstate-in";
+    };