[PATCH v13 1/3] dt-bindings: perf: Add Broadcom Raspberry Pi AXI PMU definition

Ian Rogers irogers at google.com
Sat Aug 15 10:27:10 PDT 2026


Add Device Tree bindings for the Broadcom AXI PMU hardware blocks present
in the Raspberry Pi SoC line (BCM2835, BCM2711, BCM2712).

Depending on the SoC and security configuration, these PMUs support either
direct MMIO access or routing via the Raspberry Pi firmware Mailbox IPC.
The bindings support defining 1 or 2 backing MMIO regions natively map
the system and VPU control surfaces.

Assisted-by: Antigravity:gemini-3.6-flash
Signed-off-by: Ian Rogers <irogers at google.com>
---
 .../bindings/perf/brcm,bcm2835-axiperf.yaml   | 77 +++++++++++++++++++
 1 file changed, 77 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/perf/brcm,bcm2835-axiperf.yaml

diff --git a/Documentation/devicetree/bindings/perf/brcm,bcm2835-axiperf.yaml b/Documentation/devicetree/bindings/perf/brcm,bcm2835-axiperf.yaml
new file mode 100644
index 000000000000..8a4857aa448c
--- /dev/null
+++ b/Documentation/devicetree/bindings/perf/brcm,bcm2835-axiperf.yaml
@@ -0,0 +1,77 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/perf/brcm,bcm2835-axiperf.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Broadcom BCM2835/2711/2712 AXI Performance Monitor
+
+maintainers:
+  - Ian Rogers <irogers at google.com>
+
+description: |
+  The Broadcom BCM2835 series (including BCM2711 and BCM2712) features hardware
+  performance monitors on the AXI bus for evaluating memory bandwidth and
+  system traffic. Depending on the SoC architecture, multiple monitors exist.
+  The primary
+  monitor evaluates the System fabric, while the secondary monitor evaluates the
+  VideoCore VPU hardware.
+
+  Older silicon generally restricts direct MMIO access to the VPU endpoints,
+  requiring them to be accessed over the Raspberry Pi firmware mailbox
+  interface. If the VPU endpoints are memory-mapped, they are supplied as
+  secondary resources.
+
+properties:
+  compatible:
+    enum:
+      - brcm,bcm2835-axiperf
+      - brcm,bcm2711-axiperf
+      - brcm,bcm2712-axiperf
+
+  reg:
+    minItems: 1
+    maxItems: 2
+    description: |
+      Memory-mapped I/O resource regions for the AXI PMU endpoints.
+      Typically ordered as System monitor, followed by VPU monitor if directly
+      mapped.
+
+  firmware:
+    $ref: /schemas/types.yaml#/definitions/phandle
+    description: |
+      Phandle to the Raspberry Pi firmware node. Required on older silicon
+      (BCM2835-BCM2711) where VideoCore VPU endpoints are exclusively accessed
+      via firmware mailbox IPC.
+
+required:
+  - compatible
+  - reg
+
+allOf:
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - brcm,bcm2835-axiperf
+              - brcm,bcm2711-axiperf
+    then:
+      required:
+        - firmware
+
+additionalProperties: false
+
+examples:
+  - |
+    pmu at 7e00a000 {
+        compatible = "brcm,bcm2835-axiperf";
+        reg = <0x7e00a000 0x100>;
+        firmware = <&firmware>;
+    };
+  - |
+    pmu at 7d620000 {
+        compatible = "brcm,bcm2712-axiperf";
+        reg = <0x7d620000 0x100>,
+              <0x7d630000 0x100>;
+    };
-- 
2.55.0.691.gc56d675ccc-goog




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