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References: <20230320071211.3005769-1-bhupesh.sharma@linaro.org> <7b26e32d-6f3e-4e1f-33a7-0a994ae8526d@linaro.org>
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From:   Bhupesh Sharma <bhupesh.sharma@linaro.org>
Date:   Tue, 28 Mar 2023 11:23:36 +0530
Message-ID: <CAH=2NtzGbmeWUusC_vuE5EOR8AWVKEskmuBzQxSu_vCRKuh54A@mail.gmail.com>
Subject: Re: [PATCH 1/2] dt-bindings: dma: Add support for SM6115 and QCS2290 SoCs
To:     Vladimir Zapolskiy <vladimir.zapolskiy@linaro.org>
Cc:     dmaengine@vger.kernel.org, linux-arm-msm@vger.kernel.org,
        devicetree@vger.kernel.org, agross@kernel.org,
        linux-kernel@vger.kernel.org, andersson@kernel.org,
        bhupesh.linux@gmail.com, vkoul@kernel.org,
        krzysztof.kozlowski@linaro.org, robh+dt@kernel.org,
        konrad.dybcio@linaro.org
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Hi Vladimir,

On Fri, 24 Mar 2023 at 17:38, Vladimir Zapolskiy
<vladimir.zapolskiy@linaro.org> wrote:
>
> Hi Bhupesh,
>
> On 3/20/23 09:12, Bhupesh Sharma wrote:
> > Add new compatible for BAM DMA engine version v1.7.4 which is
> > found on Qualcomm SM6115 and QCS2290 SoCs.
> >
> > While at it, also update qcom,bam-dma bindings to add comments
> > which describe the BAM DMA versions used in SM8150 and SM8250 SoCs.
> > This provides an easy reference for identifying the actual BAM DMA
> > version available on Qualcomm SoCs.
> >
> > Signed-off-by: Bhupesh Sharma <bhupesh.sharma@linaro.org>
> > ---
> >   Documentation/devicetree/bindings/dma/qcom,bam-dma.yaml | 4 +++-
> >   1 file changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/Documentation/devicetree/bindings/dma/qcom,bam-dma.yaml b/Documentation/devicetree/bindings/dma/qcom,bam-dma.yaml
> > index f1ddcf672261..4c8536df98fe 100644
> > --- a/Documentation/devicetree/bindings/dma/qcom,bam-dma.yaml
> > +++ b/Documentation/devicetree/bindings/dma/qcom,bam-dma.yaml
> > @@ -20,8 +20,10 @@ properties:
> >         - qcom,bam-v1.3.0
> >           # MSM8974, APQ8074 and APQ8084
> >         - qcom,bam-v1.4.0
> > -        # MSM8916 and SDM845
> > +        # MSM8916, SDM845, SM8150 and SM8250
> >         - qcom,bam-v1.7.0
> > +        # SM6115 and QRB2290
> > +      - qcom,bam-v1.7.4
> >
> >     clocks:
> >       maxItems: 1
>
> apparently it's a good time to implement a switch in compatible values
> similar to the one done for QCE:
>
> https://lore.kernel.org/linux-arm-msm/20230222172240.3235972-6-vladimir.zapolskiy@linaro.org/
>
> If this is done in the nearest time, then new platfrom QCE changes
> can be seamlessly added after the next merge window, also the change
> in the compatible values model shall resolve multiple technical
> concerns including the one above about 1/1 change in the series.

That is on my to-do list, but it's not of urgent priority as of now,
as fortunately the BAM DMA versions 1.7.0 and 1.7.4 are very similar
(at least in terms of how the linux driver uses them), so when we have
future use-cases that exploit the differences between the two versions
(or newer versions introduced in SoCs in the meanwhile) in the DMA
driver we can move to the soc-specific compatibles.

Thanks,
Bhupesh