[PATCH v4 1/4] dt-bindings: remoteproc: imx_rproc: document memory-region-names to avoid hidden ABI

[Frank . Li]

From: Laurentiu Mihalcea <laurentiu.mihalcea@xxxxxxx>

Document the optional memory-region-names property.
 
The driver currently derives the memory region type from the referenced
memory node name, creating a hidden DT ABI. Since memory node names are
not constrained by the binding, incorrect names can silently pass DT
validation, as seen in examples using "vdevbuffer" instead of
"vdev0buffer" ([1] and [2]).

Add memory-region-names to explicitly identify the expected memory regions
and avoid relying on memory node names as ABI.

Link: https://lore.kernel.org/imx/a3602ef8-2b77-4cc3-adef-2c4cba08a5d9@xxxxxxxxxxxx/ [1]
Link: https://lore.kernel.org/imx/alexXTYQHUs76J7v@SMW015318/T/#mb9dc709ff3adc24d9db6d30c973f37b580f6f1f9 [2]
Signed-off-by: Laurentiu Mihalcea <laurentiu.mihalcea@xxxxxxx>
Signed-off-by: Frank Li <Frank.Li@xxxxxxx>
---
Use optional property to keep back compatible with old platform.
New platform should use memory-region-names.
---
 .../devicetree/bindings/remoteproc/fsl,imx-rproc.yaml         | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/Documentation/devicetree/bindings/remoteproc/fsl,imx-rproc.yaml b/Documentation/devicetree/bindings/remoteproc/fsl,imx-rproc.yaml
index c18f71b648890..5d98d21035f8c 100644
--- a/Documentation/devicetree/bindings/remoteproc/fsl,imx-rproc.yaml
+++ b/Documentation/devicetree/bindings/remoteproc/fsl,imx-rproc.yaml
@@ -62,6 +62,15 @@ properties:
     minItems: 1
     maxItems: 32
 
+  memory-region-names:
+    minItems: 1
+    maxItems: 32
+    items:
+      anyOf:
+        - const: rsc-table
+        - pattern: "^vdev[0-9]+(buffer|vring[0-9])+$"
+        - pattern: "^m(4|7|33)-reserved(-[a-z0-9-]+)+$"
+
   power-domains:
     minItems: 2
     maxItems: 8
@@ -134,6 +143,7 @@ examples:
     imx7d-cm4 {
       compatible = "fsl,imx7d-cm4";
       memory-region = <&m4_reserved_sysmem1>, <&m4_reserved_sysmem2>;
+      memory-region-names = "m4-reserved-sysmem1", "m4-reserved-sysmem2";
       syscon = <&src>;
       clocks = <&clks IMX7D_ARM_M4_ROOT_CLK>;
     };
@@ -149,6 +159,7 @@ examples:
                 &mu 1 1
                 &mu 3 1>;
       memory-region = <&vdev0buffer>, <&vdev0vring0>, <&vdev0vring1>, <&rsc_table>;
+      memory-region-names = "vdev0buffer", "vdev0vring0", "vdev0vring1", "rsc-table";
       syscon = <&src>;
     };
 ...

-- 
2.43.0