Re: [PATCH v1 10/27] dt-bindings: gpu: panthor: Document panthor-system bindings

[Krzysztof Kozlowski <krzk@kernel.org>]

On Tue, Sep 22, 2026 at 09:45:04PM +0100, Karunika Choo wrote:
> Mali 5th-Gen AM GPUs expose an AM_SYSTEM block for GPU-wide control
> outside the main GPU register window.

A nit, subject: drop second/last, redundant "bindings". The
"dt-bindings" prefix is already stating that these are bindings.
See also:
https://elixir.bootlin.com/linux/v7.1-rc7/source/Documentation/devicetree/bindings/submitting-patches.rst#L23

> 
> Document the system node compatible, register and interrupt resources,
> GPU clock, and optional GPU regulator supply used by the AM_SYSTEM
> platform driver.
> 
> Signed-off-by: Karunika Choo <karunika.choo@arm.com>
> ---
>  .../bindings/gpu/arm,mali-gen5-am-system.yaml | 67 +++++++++++++++++++
>  MAINTAINERS                                   |  1 +
>  2 files changed, 68 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/gpu/arm,mali-gen5-am-system.yaml
> 
> diff --git a/Documentation/devicetree/bindings/gpu/arm,mali-gen5-am-system.yaml b/Documentation/devicetree/bindings/gpu/arm,mali-gen5-am-system.yaml
> new file mode 100644
> index 0000000000000..f0689bb8f05a2
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/gpu/arm,mali-gen5-am-system.yaml
> @@ -0,0 +1,67 @@
> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> +# Copyright 2026 ARM Limited. All rights reserved.
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/gpu/arm,mali-gen5-am-system.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: ARM Mali 5th-Gen GPU System Device
> +
> +maintainers:
> +  - Liviu Dudau <liviu.dudau@arm.com>
> +  - Boris Brezillon <boris.brezillon@collabora.com>
> +
> +properties:
> +  $nodename:
> +    pattern: '^panthor-system@[a-f0-9]+$'

Nope. Why would we name devices based on driver?

Node names should be generic. See also an explanation and list of
examples (not exhaustive) in DT specification:
https://devicetree-specification.readthedocs.io/en/latest/chapter2-devicetree-basics.html#generic-names-recommendation
If you cannot find a name matching your device, please check in kernel
sources for similar cases or you can grow the spec (via pull request to
DT spec repo).

Drop the nodename completely.

> +
> +  compatible:
> +    oneOf:

Drop

> +      - items:

Probably drop... but:

> +          - const: arm,mali-gen5-am-system

How can this be used alone?


> +
> +  reg:
> +    items:
> +      - description: System register

so just maxItems: 1

> +
> +  reg-names:
> +    items:
> +      - const: system

Drop entire reg-names

> +
> +  interrupts:
> +    items:
> +      - description: System interrupt

keep it simple, maxItems: 1

> +
> +  clocks:
> +    maxItems: 1
> +    description:
> +      Phandle to the GPU clock.

Drop description, obvious. Can this be something else than phandle? Can
a single clock for GPU can be something else than GPU clock?

> +
> +  gpu-supply: true

This should rather be named based on the pins/domains. Are you sure the
domain is called GPU?

> +
> +  dma-coherent: true
> +
> +required:
> +  - compatible
> +  - reg
> +  - reg-names
> +  - interrupts
> +  - clocks
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/interrupt-controller/irq.h>
> +    #include <dt-bindings/interrupt-controller/arm-gic.h>
> +
> +    panthor_system: panthor-system@68000000 {

Drop unused label

Best regards,
Krzysztof