Re: [PATCH v3 07/14] media: dt-bindings: add bindings for i.MX7 media driver

[Philipp Zabel <p.zabel@pengutronix.de>]

On Mon, 2018-05-07 at 17:21 +0100, Rui Miguel Silva wrote:
> Add bindings documentation for i.MX7 media drivers.
> 
> Signed-off-by: Rui Miguel Silva <rui.silva@linaro.org>
> ---
>  .../devicetree/bindings/media/imx7.txt        | 152 ++++++++++++++++++
>  1 file changed, 152 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/media/imx7.txt
> 
> diff --git a/Documentation/devicetree/bindings/media/imx7.txt b/Documentation/devicetree/bindings/media/imx7.txt
> new file mode 100644
> index 000000000000..06d723d6354d
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/media/imx7.txt
> @@ -0,0 +1,152 @@
> +Freescale i.MX7 Media Video Device
> +==================================
> +
> +Video Media Controller node
> +---------------------------
> +
> +This is the media controller node for video capture support. It is a
> +virtual device that lists the camera serial interface nodes that the
> +media device will control.
> +
> +Required properties:
> +- compatible : "fsl,imx7-capture-subsystem";
> +- ports      : Should contain a list of phandles pointing to camera
> +		sensor interface port of CSI
> +
> +example:
> +
> +capture-subsystem {
> +	compatible = "fsl,imx7-capture-subsystem";
> +	ports = <&csi>;
> +};

Purely from a device tree perspective, I think this node is unnecessary
on i.MX7. The reason we have it for i.MX6 is that there are two
identical IPUs on some of them, which makes it impossible to reasonably
bind the subsystem driver to one or the other of the ipu nodes. On i.MX7
the csi node is unique.

The relevant imx-media-dev.c code in imx_media_probe could be refactored
into a utility function that could be called from the probe function of
the csi driver as well.

[...]
> +csi node
> +--------
> +
> +This is device node for the CMOS Sensor Interface (CSI) which enables the chip
> +to connect directly to external CMOS image sensors.
> +
> +Required properties:
> +
> +- compatible    : "fsl,imx7-csi";
> +- reg           : base address and length of the register set for the device;
> +- interrupts    : should contain CSI interrupt;
> +- clocks        : list of clock specifiers, see
> +        Documentation/devicetree/bindings/clock/clock-bindings.txt for details;
> +- clock-names   : must contain "axi", "mclk" and "dcic" entries, matching
> +                 entries in the clock property;
> +
> +port node
> +---------
> +
> +- reg		  : (required) should be 0 for the sink port;

Not necessary, see below.

> +
> +example:
> +
> +                csi: csi@30710000 {
> +                        #address-cells = <1>;
> +                        #size-cells = <0>;
> +
> +                        compatible = "fsl,imx7-csi";
> +                        reg = <0x30710000 0x10000>;
> +                        interrupts = <GIC_SPI 7 IRQ_TYPE_LEVEL_HIGH>;
> +                        clocks = <&clks IMX7D_CLK_DUMMY>,
> +                                        <&clks IMX7D_CSI_MCLK_ROOT_CLK>,
> +                                        <&clks IMX7D_CLK_DUMMY>;
> +                        clock-names = "axi", "mclk", "dcic";
> +
> +                        port@0 {
> +                                reg = <0>;

Since there is only one port, it does not need to be numbered.

> +
> +                                csi_from_csi_mux: endpoint {
> +                                        remote-endpoint = <&csi_mux_to_csi>;
> +                                };
> +                        };
> +                };

regards
Philipp