[PATCH RFC v2 08/10] dt-bindings: arm: Fix MPAM MSC binding schema and examples

Yin Li yin.li at oss.qualcomm.com
Mon Sep 14 02:37:56 PDT 2026


Fix multiple issues in the MPAM MSC device tree binding:

Schema fixes:
- Move maintainers field before description to follow standard field order
- Change compatible from fixed items list to oneOf to allow both standalone
  arm,mpam-msc and the two-item arm,mpam-memory-controller-msc +
  arm,mpam-msc combination
- Constrain numa-node-id as uint32 with description instead of
  unconstrained
- Add phandle-array type constraint to cpus property
- Fix bracket spacing to pass yamllint

Example fixes:
- Replace arm,dsu-l3-cache with foo,a-l3-cache (no upstream schema exists)
- Fix msc at 41000 reg address from 0x0 to 0x41000 to match unit-address
- Fix ris at 2 reg value from 0 to 2 to match unit-address
- Add arm,mpam-device phandle reference and remove TODO comment
- Remove unnecessary blank lines for consistency

Co-developed-by: Huang Yiwei <huang.yiwei at oss.qualcomm.com>
Signed-off-by: Huang Yiwei <huang.yiwei at oss.qualcomm.com>
Signed-off-by: Yin Li <yin.li at oss.qualcomm.com>
---
 .../devicetree/bindings/arm/arm,mpam-msc.yaml      | 39 ++++++++++++----------
 1 file changed, 21 insertions(+), 18 deletions(-)

diff --git a/Documentation/devicetree/bindings/arm/arm,mpam-msc.yaml b/Documentation/devicetree/bindings/arm/arm,mpam-msc.yaml
index 53a6fdbbf05f..3c7b13a23ff2 100644
--- a/Documentation/devicetree/bindings/arm/arm,mpam-msc.yaml
+++ b/Documentation/devicetree/bindings/arm/arm,mpam-msc.yaml
@@ -6,19 +6,21 @@ $schema: http://devicetree.org/meta-schemas/core.yaml#
 
 title: Arm Memory System Resource Partitioning and Monitoring (MPAM)
 
+maintainers:
+  - Rob Herring <robh at kernel.org>
+
 description: |
   The Arm MPAM specification can be found here:
 
   https://developer.arm.com/documentation/ddi0598/latest
 
-maintainers:
-  - Rob Herring <robh at kernel.org>
-
 properties:
   compatible:
-    items:
+    oneOf:
       - const: arm,mpam-msc                   # Further details are discoverable
-      - const: arm,mpam-memory-controller-msc
+      - items:
+          - const: arm,mpam-memory-controller-msc
+          - const: arm,mpam-msc
 
   reg:
     maxItems: 1
@@ -34,7 +36,7 @@ properties:
   interrupt-names:
     oneOf:
       - items:
-          - enum: [ error, overflow ]
+          - enum: [error, overflow]
       - items:
           - const: error
           - const: overflow
@@ -44,7 +46,9 @@ properties:
       accurate after a settings change. For more information, see the
       Not-Ready (NRDY) bit description in the MPAM specification.
 
-  numa-node-id: true # see NUMA binding
+  numa-node-id:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: NUMA node identifier for the memory resource this MSC controls.
 
   '#address-cells':
     const: 1
@@ -72,16 +76,17 @@ patternProperties:
         maximum: 0xf
 
       cpus:
+        $ref: /schemas/types.yaml#/definitions/phandle-array
         description:
-          Phandle(s) to the CPU node(s) this RIS belongs to. By default, the parent
-          device's affinity is used.
+          Phandle(s) to the CPU node(s) this RIS belongs to. By default, the
+          parent device's affinity is used.
 
       arm,mpam-device:
         $ref: /schemas/types.yaml#/definitions/phandle
         description:
           By default, the MPAM enabled device associated with a RIS is the MSC's
-          parent node. It is possible for each RIS to be associated with different
-          devices in which case 'arm,mpam-device' should be used.
+          parent node. It is possible for each RIS to be associated with
+          different devices in which case 'arm,mpam-device' should be used.
 
     required:
       - compatible
@@ -92,14 +97,14 @@ required:
   - reg
 
 dependencies:
-  interrupts: [ interrupt-names ]
+  interrupts: [interrupt-names]
 
 additionalProperties: false
 
 examples:
   - |
     L3: cache-controller at 30000000 {
-        compatible = "arm,dsu-l3-cache", "cache";
+        compatible = "foo,a-l3-cache", "cache";
         cache-level = <3>;
         cache-unified;
 
@@ -109,7 +114,6 @@ examples:
 
         msc at 10000 {
             compatible = "arm,mpam-msc";
-
             reg = <0x10000 0x2000>;
             interrupts = <1>, <2>;
             interrupt-names = "error", "overflow";
@@ -145,7 +149,7 @@ examples:
 
         msc at 41000 {
             compatible = "arm,mpam-msc";
-            reg = <0 0x1000>;
+            reg = <0x41000 0x1000>;
             interrupts = <5>, <6>;
             interrupt-names = "error", "overflow";
             arm,not-ready-us = <1>;
@@ -155,8 +159,8 @@ examples:
 
             ris at 2 {
                 compatible = "arm,mpam-cache";
-                reg = <0>;
-                // TODO: How to map to device(s)?
+                reg = <2>;
+                arm,mpam-device = <&L3>;
             };
         };
     };
@@ -173,7 +177,6 @@ examples:
 
         msc at 10000 {
             compatible = "arm,mpam-msc";
-
             reg = <0x10000 0x2000>;
             interrupts = <7>;
             interrupt-names = "overflow";

-- 
2.34.1




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