Re: [PATCH v2 3/3] ARM: dts: gose: add composite video input

From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To: Ulrich Hecht <ulrich.hecht+renesas@gmail.com>
Cc: horms@verge.net.au, linux-media@vger.kernel.org,
	linux-renesas-soc@vger.kernel.org, magnus.damm@gmail.com,
	hans.verkuil@cisco.com, niklas.soderlund@ragnatech.se,
	geert@linux-m68k.org, sergei.shtylyov@cogentembedded.com,
	devicetree@vger.kernel.org
Subject: Re: [PATCH v2 3/3] ARM: dts: gose: add composite video input
Date: Wed, 23 Nov 2016 10:56:02 +0200	[thread overview]
Message-ID: <7242337.y1x3Jtg9DJ@avalon> (raw)
In-Reply-To: <2343930.U8AiEBNJBl@avalon>

Hello device tree maintainers,

On Tuesday 18 Oct 2016 18:50:39 Laurent Pinchart wrote:
> On Tuesday 18 Oct 2016 17:02:23 Ulrich Hecht wrote:
> > Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com>
> > ---
> > 
> >  arch/arm/boot/dts/r8a7793-gose.dts | 36 +++++++++++++++++++++++++++++++
> >  1 file changed, 36 insertions(+)
> > 
> > diff --git a/arch/arm/boot/dts/r8a7793-gose.dts
> > b/arch/arm/boot/dts/r8a7793-gose.dts index a47ea4b..2606021 100644
> > --- a/arch/arm/boot/dts/r8a7793-gose.dts
> > +++ b/arch/arm/boot/dts/r8a7793-gose.dts

[snip]

> > +	composite-in@20 {
> > +		compatible = "adi,adv7180";
> > +		reg = <0x20>;
> > +		remote = <&vin1>;
> > +
> > +		port {
> > +			adv7180: endpoint {
> > +				bus-width = <8>;
> > +				remote-endpoint = <&vin1ep>;
> > +			};
> > +		};
> 
> As explained before, you need to update the ADV7180 DT bindings first to
> document ports. I've discussed this with Hans last week, and we agreed that
> DT should model physical ports. Unfortunately the ADV7180 comes in four
> different packages with different feature sets that affect ports.
> 
> ADV7180  K CP32 Z               32-Lead Lead Frame Chip Scale Package
> ADV7180  B CP32 Z               32-Lead Lead Frame Chip Scale Package
> ADV7180 WB CP32 Z               32-Lead Lead Frame Chip Scale Package
> 
> ADV7180  B CP   Z               40-Lead Lead Frame Chip Scale Package
> ADV7180 WB CP   Z               40-Lead Lead Frame Chip Scale Package
> 
> ADV7180  K ST48 Z               48-Lead Low Profile Quad Flat Package
> ADV7180  B ST48 Z               48-Lead Low Profile Quad Flat Package
> ADV7180 WB ST48 Z               48-Lead Low Profile Quad Flat Package
> 
> ADV7180  B ST   Z               64-Lead Low Profile Quad Flat Package
> ADV7180 WB ST   Z               64-Lead Low Profile Quad Flat Package
> 
> W tells whether the part is qualified for automotive applications. It has no
> impact from a software point of view. K and B indicate the temperature
> range, and also have no software impact. The Z suffix indicates that the
> part is RoHS compliant (they all are) and also has no impact.
> 
> Unfortunately the W and K/B qualifiers come before the package qualifier.
> I'm not sure whether we could simply drop W, K/B and W and specify the
> following compatible strings
> 
> - adv7180cp32
> - adv7180cp
> - adv7180st48
> - adv7180st
> 
> or if we need more compatible strings that would match the full chip name.
> Feedback on that from the device tree maintainers would be appreciated.

Your input would be appreciated on this.

> Regardless of what compatible strings end up being used, the bindings should
> document 3 or 6 input ports depending on the model, and one output port.
> You can number the input ports from 0 to 2 or 0 to 5 depending on the model
> and the output port 3 or 6. Another option would be to number the output
> port 0 and the input ports 1 to 3 or 1 to 6 depending on the model. That
> would give a fixed number for the output port across all models, but might
> be a bit consuming as most bindings number input ports before output ports.
> 
> For the Gose board you should then add one composite connector to the device
> tree ("composite-video-connector") and connect it to port 0 of the
> ADV7180WBCP32.
> 
> > +	};
> > +

-- 
Regards,

Laurent Pinchart