[PATCH v22 2/7] dt-bindings: remoteproc: st,stm32-rproc: add st,rproc-tee

[Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>]

Add st,rproc-tee to describe the remoteprocessor control through the TEE
remoteproc backend.

The property is a phandle to the TEE remoteproc node with one argument
cell carrying the remote processor identifier.

When st,rproc-tee is present, Linux must not manage MCU reset/holdboot
directly. Update schema conditionals accordingly:
- do not require resets unconditionally
- forbid resets, reset-names and st,syscfg-holdboot when st,rproc-tee
  is present
- keep legacy holdboot checks for non-TEE configurations

Also add a DT example showing the TEE-based configuration.

Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>
---
 .../bindings/remoteproc/st,stm32-rproc.yaml   | 55 ++++++++++++++++---
 1 file changed, 46 insertions(+), 9 deletions(-)

diff --git a/Documentation/devicetree/bindings/remoteproc/st,stm32-rproc.yaml b/Documentation/devicetree/bindings/remoteproc/st,stm32-rproc.yaml
index 843679c557e7..7fe54d529e04 100644
--- a/Documentation/devicetree/bindings/remoteproc/st,stm32-rproc.yaml
+++ b/Documentation/devicetree/bindings/remoteproc/st,stm32-rproc.yaml
@@ -143,24 +143,45 @@ properties:
     maxItems: 1
     description: Default name of the remote processor firmware.
 
+  st,rproc-tee:
+    description:
+      Reference the remote processor node on TEE bus. The value is a phandle
+      reference to the remote processor node, followed by a cell specifying
+      the remote processor device identifier used by the TEE.
+    $ref: /schemas/types.yaml#/definitions/phandle-array
+    items:
+      - items:
+          - description: Phandle of the remote processor node on the TEE bus
+          - description: Remote processor device identifier used by the TEE
+
 required:
   - compatible
   - reg
-  - resets
 
 allOf:
   - if:
-      properties:
-        reset-names:
-          not:
-            contains:
-              const: hold_boot
-    then:
       required:
-        - st,syscfg-holdboot
-    else:
+        - st,rproc-tee
+    then:
       properties:
+        resets: false
+        reset-names: false
         st,syscfg-holdboot: false
+    else:
+      required:
+        - resets
+      if:
+        properties:
+          reset-names:
+            not:
+              contains:
+                const: hold_boot
+      then:
+        required:
+          - st,syscfg-holdboot
+      else:
+        properties:
+          st,syscfg-holdboot: false
 
 additionalProperties: false
 
@@ -192,5 +213,21 @@ examples:
       st,syscfg-rsc-tbl = <&tamp 0x144 0xFFFFFFFF>;
       st,syscfg-m4-state = <&tamp 0x148 0xFFFFFFFF>;
     };
+  - |
+    firmware {
+      tee_rproc: optee-rproc {
+        compatible = "80a4c275-0a47-4905-8285-1486a9771a08";
+      };
+    };
+
+    m4@10000000 {
+      compatible = "st,stm32mp1-m4";
+      reg = <0x10000000 0x40000>,
+            <0x30000000 0x40000>,
+            <0x38000000 0x10000>;
+      st,rproc-tee = <&tee_rproc 0>;
+      st,syscfg-rsc-tbl = <&tamp 0x144 0xFFFFFFFF>;
+      st,syscfg-m4-state = <&tamp 0x148 0xFFFFFFFF>;
+    };
 
 ...
-- 
2.43.0