[PATCH v4 02/10] dt-bindings: remoteproc: qcom,pas: add #cooling-cells property

[Gaurav Kohli]

Document the optional #cooling-cells property for Qualcomm PAS
remoteproc nodes so they can be used as thermal cooling devices via
the QMI Thermal Mitigation Device (TMD) interface.

Qualcomm remote processors expose TMD endpoints that support thermal
throttling through firmware. The cooling-device specifier uses 3 cells:

  <&phandle device_id min_state max_state>

where device_index selects the TMD endpoint (for example PA, modem,
or CDSP software mitigation), with constants defined in:
- dt-bindings/firmware/qcom,qmi-tmd.h

Signed-off-by: Gaurav Kohli <gaurav.kohli@xxxxxxxxxxxxxxxx>
---
 .../bindings/remoteproc/qcom,pas-common.yaml       | 39 ++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/Documentation/devicetree/bindings/remoteproc/qcom,pas-common.yaml b/Documentation/devicetree/bindings/remoteproc/qcom,pas-common.yaml
index 4607b459131b..ef11371058c4 100644
--- a/Documentation/devicetree/bindings/remoteproc/qcom,pas-common.yaml
+++ b/Documentation/devicetree/bindings/remoteproc/qcom,pas-common.yaml
@@ -79,6 +79,14 @@ properties:
       channels and devices related to the ADSP.
     unevaluatedProperties: false
 
+  '#cooling-cells':
+    description: |
+      Cooling device with three cells:
+        Cell 0: Cooling device id
+        Cell 1: Minimum cooling state
+        Cell 2: Maximum cooling state
+    const: 3
+
   glink-edge:
     $ref: /schemas/remoteproc/qcom,glink-edge.yaml#
     description:
@@ -95,3 +103,34 @@ required:
   - qcom,smem-state-names
 
 additionalProperties: true
+
+examples:
+  - |
+    #include <dt-bindings/thermal/thermal.h>
+    #include <dt-bindings/firmware/qcom,qmi-tmd.h>
+
+    remoteproc: remoteproc {
+      #cooling-cells = <3>;
+    };
+
+    thermal-zones {
+      subsystem-thermal {
+        thermal-sensors = <&tsens 0>;
+
+        trips {
+          alert: alert {
+            temperature = <95000>;
+            hysteresis = <2000>;
+            type = "passive";
+          };
+        };
+
+        cooling-maps {
+          map0 {
+            trip = <&alert>;
+            cooling-device = <&remoteproc QCOM_CDSP_TMD_CDSP_SW
+                             THERMAL_NO_LIMIT THERMAL_NO_LIMIT>;
+          };
+        };
+      };
+    };

-- 
2.34.1