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From: Keguang Zhang <keguang.zhang@gmail.com>
Date: Tue, 19 Mar 2024 10:16:59 +0800
Message-ID: <CAJhJPsWRoNaSeYs1DjSreriV6V7TgdkktQNWgs=HsNKBAiCpxw@mail.gmail.com>
Subject: Re: [PATCH v6 1/2] dt-bindings: dma: Add Loongson-1 DMA
To: Conor Dooley <conor@kernel.org>
Cc: Vinod Koul <vkoul@kernel.org>, Rob Herring <robh@kernel.org>, 
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>, Conor Dooley <conor+dt@kernel.org>, 
	linux-mips@vger.kernel.org, dmaengine@vger.kernel.org, 
	devicetree@vger.kernel.org, linux-kernel@vger.kernel.org
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On Mon, Mar 18, 2024 at 7:29=E2=80=AFPM Conor Dooley <conor@kernel.org> wro=
te:
>
> On Mon, Mar 18, 2024 at 02:18:27PM +0800, Keguang Zhang wrote:
> > On Sun, Mar 17, 2024 at 10:40=E2=80=AFPM Conor Dooley <conor@kernel.org=
> wrote:
> > >
> > > On Sat, Mar 16, 2024 at 07:33:53PM +0800, Keguang Zhang via B4 Relay =
wrote:
> > > > From: Keguang Zhang <keguang.zhang@gmail.com>
> > > >
> > > > Add devicetree binding document for Loongson-1 DMA.
> > > >
> > > > Signed-off-by: Keguang Zhang <keguang.zhang@gmail.com>
> > > > ---
> > > > V5 -> V6:
> > > >    Change the compatible to the fallback
> > > >    Some minor fixes
> > > > V4 -> V5:
> > > >    A newly added patch
> > > > ---
> > > >  .../devicetree/bindings/dma/loongson,ls1x-dma.yaml | 66 ++++++++++=
++++++++++++
> > > >  1 file changed, 66 insertions(+)
> > > >
> > > > diff --git a/Documentation/devicetree/bindings/dma/loongson,ls1x-dm=
a.yaml b/Documentation/devicetree/bindings/dma/loongson,ls1x-dma.yaml
> > > > new file mode 100644
> > > > index 000000000000..06358df725c6
> > > > --- /dev/null
> > > > +++ b/Documentation/devicetree/bindings/dma/loongson,ls1x-dma.yaml
> > > > @@ -0,0 +1,66 @@
> > > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > > > +%YAML 1.2
> > > > +---
> > > > +$id: http://devicetree.org/schemas/dma/loongson,ls1x-dma.yaml#
> > > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > > +
> > > > +title: Loongson-1 DMA Controller
> > > > +
> > > > +maintainers:
> > > > +  - Keguang Zhang <keguang.zhang@gmail.com>
> > > > +
> > > > +description:
> > > > +  Loongson-1 DMA controller provides 3 independent channels for
> > > > +  peripherals such as NAND and AC97.
> > > > +
> > > > +properties:
> > > > +  compatible:
> > > > +    oneOf:
> > > > +      - const: loongson,ls1b-dma
> > > > +      - items:
> > > > +          - enum:
> > > > +              - loongson,ls1c-dma
> > > > +          - const: loongson,ls1b-dma
> > >
> > > Aren't there several more devices in this family? Do they not have DM=
A
> > > controllers?
> > >
> > You are right. Loongson1 is a SoC family.
> > However, only 1A/1B/1C have DMA controller.
>
> You're missing the 1A then.
>
Will add 1A.

> >
> > > > +
> > > > +  reg:
> > > > +    maxItems: 1
> > > > +
> > > > +  interrupts:
> > > > +    description: Each channel has a dedicated interrupt line.
> > > > +    minItems: 1
> > > > +    maxItems: 3
> > >
> > > Is this number not fixed for each SoC?
> > >
> > Yes. Actually, it's fixed for the whole family.
>
> Then why do you have minItems: 1? Are there multiple DMA controllers
> on each SoC that only make use of a subset of the possible channels?
>
All channels are available on each SoC.
Sorry, I will remove the minItems.

Thanks for your review!

> > > > +  interrupt-names:
> > > > +    minItems: 1
> > > > +    items:
> > > > +      - pattern: ch0
> > > > +      - pattern: ch1
> > > > +      - pattern: ch2
> > >
> > > Why have you made these a pattern? There's no regex being used here a=
t
> > > all.
> > >
> > Will change items to the following regex.
> >   interrupt-names:
> >     minItems: 1
> >     items:
> >       - pattern: "^ch[0-2]$"
>


--=20
Best regards,

Keguang Zhang