Re: [PATCH v7 3/6] media: dt-bindings: Add Amlogic V4L2 video decoder

[Zhentao Guo]

Hi Krzysztof

> On Wed, Aug 12, 2026 at 10:41:25AM +0800, Zhentao Guo wrote:
> > 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@xxxxxxxxxxx>
> > ---
> >   .../devicetree/bindings/media/amlogic,s4-vdec.yaml | 111 +++++++++++++++++++++
> >   1 file changed, 111 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/media/amlogic,s4-vdec.yaml b/Documentation/devicetree/bindings/media/amlogic,s4-vdec.yaml
> > new file mode 100644
> > index 000000000000..b5af3f931b26
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/media/amlogic,s4-vdec.yaml
> > @@ -0,0 +1,111 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +# Copyright (C) 2025 Amlogic, Inc. All rights reserved
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/media/amlogic,s4-vdec.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Amlogic Video Decode Accelerator
> > +
> > +maintainers:
> > +  - Zhentao Guo <zhentao.guo@xxxxxxxxxxx>
> > +
> > +description:
> > +  The Video Decoder Accelerator present on Amlogic SOCs.
> > +  It supports stateless h264 decoding.
> > +
> > +properties:
> > +  compatible:
> > +    const: amlogic,s4-vdec
> > +
> > +  reg:
> > +    maxItems: 2
> > +
> > +  reg-names:
> > +    items:
> > +      - const: dos
> > +      - const: dmc
> > +
> > +  interrupts:
> > +    maxItems: 2
> > +
> > +  interrupt-names:
> > +    items:
> > +      - const: hvdec
> > +      - const: vdec
> vdec is the name of the module, so not really useful name.
Ok, I'll come up with a new name and change it in the next revision.
> > +
> > +  clocks:
> > +    maxItems: 3
> > +
> > +  clock-names:
> > +    items:
> > +      - const: dos
> > +      - const: vdec
> Same here
OK, but there would be a nit. In file 
drivers/soc/amlogic/meson-clk-measure.c, This clock source is also named 
*"vdec"*in|drivers/soc/amlogic/meson-clk-measure.c|, where a 
*"vdec"*clock node is created in debugfs for checking its status. Using 
a different name in the driver (including DT and binding) would make it 
inconsistent with the debugfs node naming.
> > +      - const: hevcf
> > +
> > +  power-domains:
> > +    maxItems: 2
> > +
> > +  power-domain-names:
> > +    items:
> > +      - const: vdec
> > +      - const: hvdec
> Same here.
Ok, I'll rename this.
> > +
> > +  resets:
> > +    maxItems: 1
> > +
> > +  amlogic,canvas:
> > +    description: should point to a canvas provider node
> You basically duplicate the property name. Say something useful, what is
> it used for?
I'll update the description to explain its usage in the next version.
> > +    $ref: /schemas/types.yaml#/definitions/phandle
> > +
> > +  secure-monitor:
> > +    description: phandle to the secure-monitor node
> Can a property whose type is a phandle and is called "secure-monitor" be
> not "phandle to the secure-monitor node"?
>
> Write useful code, not redundant.
Okay, I'll explain it more detailed.
> Anyway, missing vendor prefix as it is not a generic property (otherwise
> point me to generic schema defining it).
I checked the upstream code, this is not a generic property. I'll add 
the prefix.
> Best regards,
> Krzysztof

BRs

Zhentao