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Date:   Mon, 17 Jan 2022 10:23:28 +0100
From:   Niklas =?iso-8859-1?Q?S=F6derlund?= 
        <niklas.soderlund@ragnatech.se>
To:     Jacopo Mondi <jacopo@jmondi.org>
Cc:     Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Geert Uytterhoeven <geert+renesas@glider.be>,
        Prabhakar <prabhakar.csengg@gmail.com>,
        Biju Das <biju.das.jz@bp.renesas.com>,
        linux-media@vger.kernel.org, linux-renesas-soc@vger.kernel.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] media: dt-bindings: media: renesas,csi2: Update
 data-lanes property
Message-ID: <YeU1kDee7L26QJ86@oden.dyn.berto.se>
References: <20220113103215.27080-1-prabhakar.mahadev-lad.rj@bp.renesas.com>
 <20220117081110.bkwr3ttoexgr2wjt@uno.localdomain>
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Hello Jacopo,

On 2022-01-17 09:11:10 +0100, Jacopo Mondi wrote:
> Hello Prabhakar,
> 
> On Thu, Jan 13, 2022 at 10:32:14AM +0000, Lad Prabhakar wrote:
> > CSI-2 (CSI4LNK0) on R-Car and RZ/G2 supports 4-lane mode which is already
> > handled by rcar-csi2.c driver. This patch updates the data-lanes property
> > to describe the same.
> >
> > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> > ---
> >  .../devicetree/bindings/media/renesas,csi2.yaml          | 9 ++++++++-
> >  1 file changed, 8 insertions(+), 1 deletion(-)
> >
> > diff --git a/Documentation/devicetree/bindings/media/renesas,csi2.yaml b/Documentation/devicetree/bindings/media/renesas,csi2.yaml
> > index e6a036721082..064a0a4c5737 100644
> > --- a/Documentation/devicetree/bindings/media/renesas,csi2.yaml
> > +++ b/Documentation/devicetree/bindings/media/renesas,csi2.yaml
> > @@ -67,7 +67,14 @@ properties:
> >                  maxItems: 1
> >
> >                data-lanes:
> > -                maxItems: 1
> > +                items:
> > +                  minItems: 1
> > +                  maxItems: 4
> > +                  items:
> > +                    - const: 1
> > +                    - const: 2
> > +                    - const: 3
> > +                    - const: 4
> 
> Seeing "maxItems: 1" there confuses me too, as the property is an
> array of data-lanes, but I'm afraid your change does not what you
> intend as it would allow you to specify the number of data lanes as an
> integer rather than as an array.
> 
> I think it would probably be correct to set
> 
>                 data-lanes: true
> 
> (maybe maxItems: 1 is correct already)
> 
> And restrict the number of valid combinations in the board DTS file
> with a construct like:
> 
>     data-lanes:
>       oneOf:
>         - items:
>             - const: 1
>             - const: 2
>             - const: 3
>             - const: 4
>         - items:
>             - const: 1
>             - const: 2

I don't think this is correct, what if data lanes 2 and 3 are used?

> 
> Thanks
>    j
> 
> >
> >              required:
> >                - clock-lanes
> > --
> > 2.17.1
> >

-- 
Kind Regards,
Niklas S?derlund