On Mon, Jul 17, 2017 at 07:03:55PM +0200, 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@xxxxxxxxxxxx>
> ---
> .../devicetree/bindings/media/rcar-csi2.txt | 118 +++++++++++++++++++++
> 1 file changed, 118 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..c298a7d821153219
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/media/rcar-csi2.txt
> @@ -0,0 +1,118 @@
> +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.
> + - "renesas,rcar-gen3-csi2" for a generic R-Car Gen3 compatible device.
> +
> + When compatible with a generic version nodes must list the
> + SoC-specific version corresponding to the platform first
> + followed by the generic version.
> +
> + - 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)
> + - Reg 0 - sub-node describing the endpoint that is the video source
Endpoint 0
It's not very clear that you are talking endpoints here. I had to look
at the example.
> +
> +- Port 1 - VIN instances (Mandatory for all VIN present in the SoC)
> + - Reg 0 - sub-node describing the endpoint that is VIN0
Endpoint 0
> + - Reg 1 - sub-node describing the endpoint that is VIN1
and so on.
> + - Reg 2 - sub-node describing the endpoint that is VIN2
> + - Reg 3 - sub-node describing the endpoint that is VIN3
> + - Reg 4 - sub-node describing the endpoint that is VIN4
> + - Reg 5 - sub-node describing the endpoint that is VIN5
> + - Reg 6 - sub-node describing the endpoint that is VIN6
> + - Reg 7 - sub-node describing the endpoint that is VIN7
> +
> +Example:
> +
> +/* SoC properties */
> +
> + csi20: csi2@fea80000 {
> + compatible = "renesas,r8a7796-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>;
> + status = "disabled";
Don't show status in examples.
> +
> + ports {
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + 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>;
> + };
> + };
> + };
> + };
> +
> +/* Board properties */
Don't split the example. This is source convention which is independent
of the binding.
> +
> + &csi20 {
> + status = "okay";
> +
> + ports {
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + port@0 {
> + reg = <0>;
Missing #address-cells and #size-cells.
> + csi20_in: endpoint@0 {
> + clock-lanes = <0>;
> + data-lanes = <1>;
> + remote-endpoint = <&adv7482_txb>;
> + };
> + };
> + };
> + };
> --
> 2.13.1
>
> --
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