Re: [PATCH 1/3] dt-bindings: vdec: Add binding document of Amlogic decoder accelerator

[Zhentao Guo]

在 2025/10/27 21:05, Krzysztof Kozlowski 写道:
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> On 27/10/2025 06:42, Zhentao Guo via B4 Relay wrote:
> > From: Zhentao Guo <zhentao.guo@xxxxxxxxxxx>
> >
> > Add dt-binding of the Amlogic hardware decoder accelerator.
> Please use subject prefixes matching the subsystem. You can get them for
> example with `git log --oneline -- DIRECTORY_OR_FILE` on the directory
> your patch is touching. For bindings, the preferred subjects are
> explained here:
> https://www.kernel.org/doc/html/latest/devicetree/bindings/submitting-patches.html#i-for-patch-submitters
>
> A nit, subject: drop second/last, redundant "binding document for". The
> "dt-bindings" prefix is already stating that these are bindings.
> See also:
> https://elixir.bootlin.com/linux/v6.17-rc3/source/Documentation/devicetree/bindings/submitting-patches.rst#L18
Thank you for pointing this out and providing the guidance. We'll revise 
the subjects according to the specifications.
> > Signed-off-by: Zhentao Guo <zhentao.guo@xxxxxxxxxxx>
> > ---
> >   .../bindings/media/amlogic,vcodec-dec.yaml         | 96 ++++++++++++++++++++++
> >   1 file changed, 96 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/media/amlogic,vcodec-dec.yaml b/Documentation/devicetree/bindings/media/amlogic,vcodec-dec.yaml
> > new file mode 100644
> > index 000000000000..6cea8af72639
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/media/amlogic,vcodec-dec.yaml
> Filename matching compatible.
Yes, we will correct this.
> > @@ -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
> > +---
> > +$id: http://devicetree.org/schemas/media/amlogic,vcodec-dec.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Amlogic Video Decode Accelerator
> > +
> > +maintainers:
> > +  - Zhentao Guo <zhentao.guo@xxxxxxxxxxx>
> > +
> > +description: |
>
> Do not need '|' unless you need to preserve formatting.
OK, I'll get rid of this.
> > +  The Video Decoder Accelerator present on Amlogic SOCs.
> > +  It supports stateless h264 decoding.
> > +
> > +properties:
> > +  compatible:
> > +    const: amlogic,s4-vcodec-dec
> > +
> > +  reg:
> > +    maxItems: 2
> > +
> > +  reg-names:
> > +    items:
> > +      - const: dosbus
> > +      - const: dmcbus
> Is "bus" really name of this in datasheet?
No, it is not from the datasheet, in fact it was inherited from the
older SOCs. Do you have any suggestions about this?
> > +
> > +  interrupts:
> > +    maxItems: 3
> > +
> > +  interrupt-names:
> > +    items:
> > +      - const: mailbox_0
> > +      - const: mailbox_1
> > +      - const: mailbox_2
> Useless names, so just drop interrupt-names property.
Yes, we don't need the interrupt names. I'll drop them.
> > +
> > +  clocks:
> > +    maxItems: 3
> > +
> > +  clock-names:
> > +    items:
> > +      - const: vdec
> > +      - const: clk_vdec_mux
> > +      - const: clk_hevcf_mux
> > +
> > +  power-domains:
> > +    maxItems: 2
> > +
> > +  power-domain-names:
> > +    items:
> > +      - const: pwrc-vdec
> Drop pwrc
>
> > +      - const: pwrc-hevc
> Drop pwrc
Ok, I'll drop the two pwrc(s) above.
> Missing iommus. I really doubt hardware works without IOMMU.

IOMMU is not supported by Amlogic SOCs, the decoder hardware needs to 
use contiguous memory.

> Best regards,
> Krzysztof