linux-kernel - Re: [PATCH v8, 1/6] dt-bindings: mediatek: add rdma_fifo_size description for mt8183 display

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Message-ID: <CAAOTY__y70tF2ORQDgZfk7RfeQm4fKraPnOQWMDnWsBb7HmZnQ@mail.gmail.com>
Date:   Fri, 11 Dec 2020 22:46:34 +0800
From:   Chun-Kuang Hu <chunkuang.hu@...nel.org>
To:     Yongqiang Niu <yongqiang.niu@...iatek.com>
Cc:     Chun-Kuang Hu <chunkuang.hu@...nel.org>,
        CK Hu <ck.hu@...iatek.com>,
        Philipp Zabel <p.zabel@...gutronix.de>,
        Rob Herring <robh+dt@...nel.org>,
        Matthias Brugger <matthias.bgg@...il.com>,
        Mark Rutland <mark.rutland@....com>,
        DTML <devicetree@...r.kernel.org>,
        David Airlie <airlied@...ux.ie>,
        linux-kernel <linux-kernel@...r.kernel.org>,
        DRI Development <dri-devel@...ts.freedesktop.org>,
        "moderated list:ARM/Mediatek SoC support" 
        <linux-mediatek@...ts.infradead.org>,
        Daniel Vetter <daniel@...ll.ch>,
        Linux ARM <linux-arm-kernel@...ts.infradead.org>
Subject: Re: [PATCH v8, 1/6] dt-bindings: mediatek: add rdma_fifo_size
 description for mt8183 display

Hi, Yongqiang:

Yongqiang Niu <yongqiang.niu@...iatek.com> 於 2020年12月11日 週五 上午8:43寫道：
>
> On Thu, 2020-12-10 at 23:40 +0800, Chun-Kuang Hu wrote:
> > Hi, Yongqiang:
> >
> > Yongqiang Niu <yongqiang.niu@...iatek.com> 於 2020年12月10日 週四 下午5:22寫道：
> > >
> > > rdma fifo size may be different even in same SOC, add this
> > > property to the corresponding rdma
> > >
> > > Signed-off-by: Yongqiang Niu <yongqiang.niu@...iatek.com>
> > > ---
> > >  .../bindings/display/mediatek/mediatek,disp.txt          | 16 ++++++++++++++++
> > >  1 file changed, 16 insertions(+)
> > >
> > > diff --git a/Documentation/devicetree/bindings/display/mediatek/mediatek,disp.txt b/Documentation/devicetree/bindings/display/mediatek/mediatek,disp.txt
> > > index 1212207..64c64ee 100644
> > > --- a/Documentation/devicetree/bindings/display/mediatek/mediatek,disp.txt
> > > +++ b/Documentation/devicetree/bindings/display/mediatek/mediatek,disp.txt
> > > @@ -66,6 +66,13 @@ Required properties (DMA function blocks):
> > >    argument, see Documentation/devicetree/bindings/iommu/mediatek,iommu.txt
> > >    for details.
> > >
> > > +Optional properties (RDMA function blocks):
> > > +- mediatek,rdma_fifo_size: rdma fifo size may be different even in same SOC, add this
> > > +  property to the corresponding rdma
> > > +  the value is the Max value which defined in hardware data sheet.
> > > +  rdma_fifo_size of rdma0 in mt8183 is 5120
> > > +  rdma_fifo_size of rdma1 in mt8183 is 2048
> > > +
> > >  Examples:
> > >
> > >  mmsys: clock-controller@...00000 {
> > > @@ -207,3 +214,12 @@ od@...23000 {
> > >         power-domains = <&scpsys MT8173_POWER_DOMAIN_MM>;
> > >         clocks = <&mmsys CLK_MM_DISP_OD>;
> > >  };
> > > +
> > > +rdma1: rdma@...0c000 {
> > > +       compatible = "mediatek,mt8183-disp-rdma";
> > > +       reg = <0 0x1400c000 0 0x1000>;
> > > +       interrupts = <GIC_SPI 229 IRQ_TYPE_LEVEL_LOW>;
> > > +       power-domains = <&scpsys MT8183_POWER_DOMAIN_DISP>;
> > > +       clocks = <&mmsys CLK_MM_DISP_RDMA1>;
> > > +       mediatek,rdma_fifo_size = <2048>;
> > > +};
> >
> > In [1], Rob has suggest that not add example of rdma1, it's better to
> > add mediatek,rdma_fifo_size in rdma0 for example.
> >
> > [1] https://patchwork.kernel.org/project/linux-mediatek/patch/1596855231-5782-2-git-send-email-yongqiang.niu@mediatek.com/
> >
> > Regards,
> > Chun-Kuang.
>
> the description of rdma0 is mt8173, and mt8173 rdma driver set the
> correspond fifo size already ok like this:
> static const struct mtk_disp_rdma_data mt8173_rdma_driver_data = {
>         .fifo_size = SZ_8K,
> };
>
> please double confirm shall we add this information into rdma0
> description.
>

Device tree is used to describe hardware. That means device tree
description should not consider your driver's implementation.
mediatek,rdma-fifo-size of mt8173-rdma0 is 8K, so I could write this
information in device node because this hardware is.

Regards,
Chun-Kuang.

>
> >
> > > --
> > > 1.8.1.1.dirty
> > > _______________________________________________
> > > Linux-mediatek mailing list
> > > Linux-mediatek@...ts.infradead.org
> > > http://lists.infradead.org/mailman/listinfo/linux-mediatek
>

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