Re: [PATCH RFC v4 1/4] media: dt-bindings: Add Amlogic V4L2 video decoder

[Krzysztof Kozlowski <krzk@kernel.org>]

On 13/02/2026 06:12, Zhentao Guo via B4 Relay wrote:
> From: Zhentao Guo <zhentao.guo@amlogic.com>
> 
> Describe the initial support for the V4L2 stateless video decoder
> driver used with the Amlogic S4 (S805X2) platform.
> 
> Signed-off-by: Zhentao Guo <zhentao.guo@amlogic.com>
> ---
>  .../bindings/media/amlogic,s4-vcodec-dec.yaml      | 96 ++++++++++++++++++++++
>  1 file changed, 96 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/media/amlogic,s4-vcodec-dec.yaml b/Documentation/devicetree/bindings/media/amlogic,s4-vcodec-dec.yaml
> new file mode 100644
> index 000000000000..88780514d06c
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/media/amlogic,s4-vcodec-dec.yaml
> @@ -0,0 +1,96 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +# Copyright (C) 2025 Amlogic, Inc. All rights reserved
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/media/amlogic,s4-vcodec-dec.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Amlogic Video Decode Accelerator
> +
> +maintainers:
> +  - Zhentao Guo <zhentao.guo@amlogic.com>
> +
> +description:
> +  The Video Decoder Accelerator present on Amlogic SOCs.
> +  It supports stateless h264 decoding.
> +
> +properties:
> +  compatible:
> +    const: amlogic,s4-vcodec-dec

Why do you repeat "dec" twice? codec means decoder, so what is the last
"dec" about?

> +
> +  reg:
> +    maxItems: 2
> +
> +  reg-names:
> +    items:
> +      - const: dos
> +      - const: dmc
> +
> +  interrupts:
> +    maxItems: 3
> +
> +  clocks:
> +    maxItems: 3
> +
> +  clock-names:
> +    items:
> +      - const: vdec
> +      - const: clk_vdec_mux
> +      - const: clk_hevcf_mux

Name them based on their role/name in this device. Why this device would
care that it receives a mux? Not a div? or not a gate?

> +
> +  power-domains:
> +    maxItems: 2
> +
> +  power-domain-names:
> +    items:
> +      - const: vdec
> +      - const: hevc
> +
> +  resets:
> +    maxItems: 1
> +
> +  amlogic,canvas:
> +    description: should point to a canvas provider node

Why? What for?

What is canvas provider?


> +    $ref: /schemas/types.yaml#/definitions/phandle
> +
> +required:
> +  - compatible
> +  - reg
> +  - reg-names
> +  - interrupts
> +  - clocks
> +  - clock-names
> +  - power-domains
> +  - power-domain-names
> +



Best regards,
Krzysztof