Re: [PATCH v2 06/19] dt-bindings: media: sun6i-a31-csi: Add MIPI CSI-2 input port

From: Rob Herring <robh@kernel.org>
To: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Cc: Maxime Ripard <maxime@cerno.tech>,
	linux-media@vger.kernel.org, devicetree@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
	devel@driverdev.osuosl.org, linux-sunxi@googlegroups.com,
	Yong Deng <yong.deng@magewell.com>,
	Mauro Carvalho Chehab <mchehab@kernel.org>,
	Chen-Yu Tsai <wens@csie.org>,
	Jernej Skrabec <jernej.skrabec@siol.net>,
	Jonathan Corbet <corbet@lwn.net>,
	Kishon Vijay Abraham I <kishon@ti.com>,
	Vinod Koul <vkoul@kernel.org>,
	Helen Koike <helen.koike@collabora.com>,
	Dafna Hirschfeld <dafna.hirschfeld@collabora.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Philipp Zabel <p.zabel@pengutronix.de>,
	Sakari Ailus <sakari.ailus@linux.intel.com>,
	Hans Verkuil <hans.verkuil@cisco.com>,
	Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
	kevin.lhopital@hotmail.com
Subject: Re: [PATCH v2 06/19] dt-bindings: media: sun6i-a31-csi: Add MIPI CSI-2 input port
Date: Tue, 8 Dec 2020 13:54:32 -0600	[thread overview]
Message-ID: <20201208195432.GA2973474@robh.at.kernel.org> (raw)
In-Reply-To: <X8ehzCjZJ3yC8YtJ@aptenodytes>

On Wed, Dec 02, 2020 at 03:16:44PM +0100, Paul Kocialkowski wrote:
> Hi,
> 
> On Tue 01 Dec 20, 11:43, Maxime Ripard wrote:
> > On Sat, Nov 28, 2020 at 03:28:26PM +0100, Paul Kocialkowski wrote:
> > > The A31 CSI controller supports two distinct input interfaces:
> > > parallel and an external MIPI CSI-2 bridge. The parallel interface
> > > is often connected to a set of hardware pins while the MIPI CSI-2
> > > bridge is an internal FIFO-ish link. As a result, these two inputs
> > > are distinguished as two different ports.
> > > 
> > > Note that only one of the two may be present on a controller instance.
> > > For example, the V3s has one controller dedicated to MIPI-CSI2 and one
> > > dedicated to parallel.
> > > 
> > > Update the binding with an explicit ports node that holds two distinct
> > > port nodes: one for parallel input and one for MIPI CSI-2.
> > > 
> > > This is backward-compatible with the single-port approach that was
> > > previously taken for representing the parallel interface port, which
> > > stays enumerated as fwnode port 0. However, it is now marked as
> > > deprecated and the multi-port approach should be preferred.
> > > 
> > > Note that additional ports may be added in the future, especially to
> > > support feeding the CSI controller's output to the ISP.
> > > 
> > > Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
> > > ---
> > >  .../media/allwinner,sun6i-a31-csi.yaml        | 86 ++++++++++++++++---
> > >  1 file changed, 73 insertions(+), 13 deletions(-)
> > > 
> > > diff --git a/Documentation/devicetree/bindings/media/allwinner,sun6i-a31-csi.yaml b/Documentation/devicetree/bindings/media/allwinner,sun6i-a31-csi.yaml
> > > index 1fd9b5532a21..3bcee2d44f3c 100644
> > > --- a/Documentation/devicetree/bindings/media/allwinner,sun6i-a31-csi.yaml
> > > +++ b/Documentation/devicetree/bindings/media/allwinner,sun6i-a31-csi.yaml
> > > @@ -43,6 +43,7 @@ properties:
> > >    # See ./video-interfaces.txt for details
> > >    port:
> > >      type: object
> > > +    deprecated: true
> > 
> > I'm not sure we want to deprecate it. There's some SoCs with the same
> > controller but without the MIPI-CSI block where this would be completely
> > valid
> 
> I think we'll need to deprecate it when adding support for the ISP anyway,
> so I figured we might as well do it now. But I'm okay to postpone this for now.
> 
> > >      properties:
> > >        endpoint:
> > > @@ -67,6 +68,59 @@ properties:
> > >  
> > >      additionalProperties: false
> > >  
> > > +  ports:
> > > +    type: object
> > > +
> > > +    properties:
> > > +      port@0:
> > > +        type: object
> > > +        description: Parallel input port, connect to a parallel sensor
> > > +
> > > +        properties:
> > > +          reg:
> > > +            const: 0
> > > +
> > > +          endpoint:
> > > +            type: object
> > > +
> > > +            properties:
> > > +              remote-endpoint: true
> > > +
> > > +              bus-width:
> > > +                enum: [ 8, 10, 12, 16 ]
> > > +
> > > +              pclk-sample: true
> > > +              hsync-active: true
> > > +              vsync-active: true
> > > +
> > > +            required:
> > > +              - bus-width
> > > +              - remote-endpoint
> > > +
> > > +        required:
> > > +          - endpoint
> > > +
> > > +        additionalProperties: false
> > > +
> > > +      port@1:
> > > +        type: object
> > > +        description: MIPI CSI-2 bridge input port
> > > +
> > > +        properties:
> > > +          reg:
> > > +            const: 1
> > > +
> > > +          endpoint:
> > > +            type: object
> > > +
> > > +            properties:
> > > +              remote-endpoint: true
> > > +
> > > +            required:
> > > +              - remote-endpoint
> > > +
> > > +        additionalProperties: false
> > 
> > There's a schema for the OF-graph now, you'll want to use it.
> 
> I didn't know that, thanks for the tip! Will look into it.

There's about to be. Don't use what's in graph.yaml (in dt-schema) yet.

Rob