Re: [PATCH v10 1/2] media: rcar-csi2: add Renesas R-Car MIPI CSI-2 receiver documentation

["Niklas Söderlund" <niklas.soderlund@ragnatech.se>]

Hej Sakari,

Tack för din feedback.

On 2017-11-11 00:11:13 +0200, Sakari Ailus wrote:
> Hejssan,
> 
> On Fri, Nov 10, 2017 at 02:31:36PM +0100, Niklas Söderlund wrote:
> > Documentation for Renesas R-Car MIPI CSI-2 receiver. The CSI-2 receivers
> > are located between the video sources (CSI-2 transmitters) and the video
> > grabbers (VIN) on Gen3 of Renesas R-Car SoC.
> > 
> > Each CSI-2 device is connected to more then one VIN device which
> > simultaneously can receive video from the same CSI-2 device. Each VIN
> > device can also be connected to more then one CSI-2 device. The routing
> > of which link are used are controlled by the VIN devices. There are only
> > a few possible routes which are set by hardware limitations, which are
> > different for each SoC in the Gen3 family.
> > 
> > To work with the limitations of routing possibilities it is necessary
> > for the DT bindings to describe which VIN device is connected to which
> > CSI-2 device. This is why port 1 needs to to assign reg numbers for each
> > VIN device that be connected to it. To setup and to know which links are
> > valid for each SoC is the responsibility of the VIN driver since the
> > register to configure it belongs to the VIN hardware.
> > 
> > Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> > ---
> >  .../devicetree/bindings/media/rcar-csi2.txt        | 104 +++++++++++++++++++++
> >  MAINTAINERS                                        |   1 +
> >  2 files changed, 105 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/media/rcar-csi2.txt
> > 
> > diff --git a/Documentation/devicetree/bindings/media/rcar-csi2.txt b/Documentation/devicetree/bindings/media/rcar-csi2.txt
> > new file mode 100644
> > index 0000000000000000..24705d8997b14a10
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/media/rcar-csi2.txt
> 
> How about using vendor prefix and comma for the file name? Most others in
> the directory do so, including other Renesas bindings.

To be clear you are suggesting a rename to 'renesas,rcar-csi2.txt'?  I'm 
not oppose to that but chose this name as this driver is closely tied to 
the rcar-vin driver which is documented in:

Documentation/devicetree/bindings/media/rcar_vin.txt

You also had comments on patch 2/2 so I will resend this series once 
more addressing them so will rename this as you suggests.

> 
> > @@ -0,0 +1,104 @@
> > +Renesas R-Car MIPI CSI-2
> > +------------------------
> > +
> > +The rcar-csi2 device provides MIPI CSI-2 capabilities for the Renesas R-Car
> > +family of devices. It is to be used in conjunction with the R-Car VIN module,
> > +which provides the video capture capabilities.
> > +
> > +Mandatory properties
> > +--------------------
> > + - compatible: Must be one or more of the following
> > +   - "renesas,r8a7795-csi2" for the R8A7795 device.
> > +   - "renesas,r8a7796-csi2" for the R8A7796 device.
> > +
> > + - reg: the register base and size for the device registers
> > + - interrupts: the interrupt for the device
> > + - clocks: Reference to the parent clock
> > +
> > +The device node shall contain two 'port' child nodes according to the
> > +bindings defined in Documentation/devicetree/bindings/media/
> > +video-interfaces.txt. Port 0 shall connect the node that is the video
> > +source for to the CSI-2. Port 1 shall connect all the R-Car VIN
> > +modules, which can make use of the CSI-2 module.
> > +
> > +- Port 0 - Video source (Mandatory)
> > +	- Endpoint 0 - sub-node describing the endpoint that is the video source
> > +
> > +- Port 1 - VIN instances (Mandatory for all VIN present in the SoC)
> > +	- Endpoint 0 - sub-node describing the endpoint that is VIN0
> > +	- Endpoint 1 - sub-node describing the endpoint that is VIN1
> > +	- Endpoint 2 - sub-node describing the endpoint that is VIN2
> > +	- Endpoint 3 - sub-node describing the endpoint that is VIN3
> > +	- Endpoint 4 - sub-node describing the endpoint that is VIN4
> > +	- Endpoint 5 - sub-node describing the endpoint that is VIN5
> > +	- Endpoint 6 - sub-node describing the endpoint that is VIN6
> > +	- Endpoint 7 - sub-node describing the endpoint that is VIN7
> > +
> > +Example:
> > +
> > +	csi20: csi2@fea80000 {
> > +		compatible = "renesas,r8a7796-csi2", "renesas,rcar-gen3-csi2";
> > +		reg = <0 0xfea80000 0 0x10000>;
> > +		interrupts = <0 184 IRQ_TYPE_LEVEL_HIGH>;
> > +		clocks = <&cpg CPG_MOD 714>;
> > +		power-domains = <&sysc R8A7796_PD_ALWAYS_ON>;
> > +		resets = <&cpg 714>;
> > +
> > +		ports {
> > +			#address-cells = <1>;
> > +			#size-cells = <0>;
> > +
> > +			port@0 {
> > +				#address-cells = <1>;
> > +				#size-cells = <0>;
> > +
> > +				reg = <0>;
> > +
> > +				csi20_in: endpoint@0 {
> > +					clock-lanes = <0>;
> > +					data-lanes = <1>;
> > +					remote-endpoint = <&adv7482_txb>;
> > +				};
> > +			};
> > +
> > +			port@1 {
> > +				#address-cells = <1>;
> > +				#size-cells = <0>;
> > +
> > +				reg = <1>;
> > +
> > +				csi20vin0: endpoint@0 {
> > +					reg = <0>;
> > +					remote-endpoint = <&vin0csi20>;
> > +				};
> > +				csi20vin1: endpoint@1 {
> > +					reg = <1>;
> > +					remote-endpoint = <&vin1csi20>;
> > +				};
> > +				csi20vin2: endpoint@2 {
> > +					reg = <2>;
> > +					remote-endpoint = <&vin2csi20>;
> > +				};
> > +				csi20vin3: endpoint@3 {
> > +					reg = <3>;
> > +					remote-endpoint = <&vin3csi20>;
> > +				};
> > +				csi20vin4: endpoint@4 {
> > +					reg = <4>;
> > +					remote-endpoint = <&vin4csi20>;
> > +				};
> > +				csi20vin5: endpoint@5 {
> > +					reg = <5>;
> > +					remote-endpoint = <&vin5csi20>;
> > +				};
> > +				csi20vin6: endpoint@6 {
> > +					reg = <6>;
> > +					remote-endpoint = <&vin6csi20>;
> > +				};
> > +				csi20vin7: endpoint@7 {
> > +					reg = <7>;
> > +					remote-endpoint = <&vin7csi20>;
> > +				};
> > +			};
> > +		};
> > +	};
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index adbf69306e9ee3d2..fa81ee6e80274646 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -8565,6 +8565,7 @@ L:	linux-media@vger.kernel.org
> >  L:	linux-renesas-soc@vger.kernel.org
> >  T:	git git://linuxtv.org/media_tree.git
> >  S:	Supported
> > +F:	Documentation/devicetree/bindings/media/rcar-csi2.txt
> >  F:	Documentation/devicetree/bindings/media/rcar_vin.txt
> >  F:	drivers/media/platform/rcar-vin/
> >  
> 
> -- 
> Sakari Ailus
> e-mail: sakari.ailus@iki.fi

-- 
Regards,
Niklas Söderlund