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

[Krzysztof Kozlowski <krzk@kernel.org>]

On 15/08/2026 19:27, Ian Rogers wrote:
> 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@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@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

This was already rejected.

https://lore.kernel.org/all/?q=broadcom+firmware

> +    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.


Best regards,
Krzysztof