[PATCH 1/2] perf: Add Arm CMN-600 DT binding

Robin Murphy robin.murphy at arm.com
Wed Aug 5 08:56:49 EDT 2020


Document the requirements for the CMN-600 DT binding. The internal
topology is almost entirely discoverable by walking a tree of ID
registers, but sadly both the starting point for that walk and the
exact format of those registers are configuration-dependent and not
discoverable from some sane fixed location. Oh well.

Signed-off-by: Robin Murphy <robin.murphy at arm.com>
---
 .../devicetree/bindings/perf/arm-cmn.yaml     | 57 +++++++++++++++++++
 1 file changed, 57 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/perf/arm-cmn.yaml

diff --git a/Documentation/devicetree/bindings/perf/arm-cmn.yaml b/Documentation/devicetree/bindings/perf/arm-cmn.yaml
new file mode 100644
index 000000000000..167491787088
--- /dev/null
+++ b/Documentation/devicetree/bindings/perf/arm-cmn.yaml
@@ -0,0 +1,57 @@
+# SPDX-License-Identifier: GPL-2.0
+# Copyright 2020 Arm Ltd.
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/perf/arm-cmn.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Arm CMN (Coherent Mesh Network) Performance Monitors
+
+maintainers:
+  - Robin Murphy <robin.murphy at arm.com>
+
+properties:
+  compatible:
+    const: arm,cmn-600
+
+  reg:
+    items:
+      - description: Physical address of the base (PERIPHBASE) and
+          size (up to 64MB) of the configuration address space.
+
+  interrupts:
+    minItems: 1
+    maxItems: 4
+    items:
+      - description: Overflow interrupt for DTC0
+      - description: Overflow interrupt for DTC1
+      - description: Overflow interrupt for DTC2
+      - description: Overflow interrupt for DTC3
+    description: One interrupt for each DTC domain implemented must
+      be specified, in order. DTC0 is always present.
+
+  arm,root-node :
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: Offset from PERIPHBASE of the configuration
+      discovery node (see TRM definition of ROOTNODEBASE).
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - arm,root-node
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+    pmu at 50000000 {
+        compatible = "arm,cmn-600";
+        reg = <0x50000000 0x4000000>;
+        /* 4x2 mesh with one DTC, and CFG node at 0,1,1,0 */
+        interrupts = <GIC_SPI 46 IRQ_TYPE_LEVEL_HIGH>;
+        arm,root-node = <0x104000>;
+    };
+...
-- 
2.28.0.dirty




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