Hi Yong,
On Wed, Sep 26, 2018 at 04:40:04PM +0800, Yong Deng wrote:
> Add binding documentation for Allwinner V3s CSI.
>
> Acked-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxx>
> Acked-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
I know... but I have a few more comments.
> Reviewed-by: Rob Herring <robh@xxxxxxxxxx>
> Signed-off-by: Yong Deng <yong.deng@xxxxxxxxxxxx>
> ---
> .../devicetree/bindings/media/sun6i-csi.txt | 59 ++++++++++++++++++++++
> 1 file changed, 59 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/media/sun6i-csi.txt
>
> diff --git a/Documentation/devicetree/bindings/media/sun6i-csi.txt b/Documentation/devicetree/bindings/media/sun6i-csi.txt
> new file mode 100644
> index 000000000000..2ff47a9507a6
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/media/sun6i-csi.txt
> @@ -0,0 +1,59 @@
> +Allwinner V3s Camera Sensor Interface
> +-------------------------------------
> +
> +Allwinner V3s SoC features two CSI module. CSI0 is used for MIPI CSI-2
> +interface and CSI1 is used for parallel interface.
> +
> +Required properties:
> + - compatible: value must be "allwinner,sun8i-v3s-csi"
> + - reg: base address and size of the memory-mapped region.
> + - interrupts: interrupt associated to this IP
> + - clocks: phandles to the clocks feeding the CSI
> + * bus: the CSI interface clock
> + * mod: the CSI module clock
> + * ram: the CSI DRAM clock
> + - clock-names: the clock names mentioned above
> + - resets: phandles to the reset line driving the CSI
> +
> +Each CSI node should contain one 'port' child node with one child 'endpoint'
> +node, according to the bindings defined in
> +Documentation/devicetree/bindings/media/video-interfaces.txt. As mentioned
> +above, the endpoint's bus type should be MIPI CSI-2 for CSI0 and parallel or
> +Bt656 for CSI1.
Which port represents CSI0 and which one is CSI1? That needs to be
documented.
> +
> +Endpoint node properties for CSI1
How about CSI0? I'd expect at least data-lanes, and clock-lanes as well if
the hardware supports lane mapping.
> +---------------------------------
> +
> +- remote-endpoint : (required) a phandle to the bus receiver's endpoint
> + node
> +- bus-width: : (required) must be 8, 10, 12 or 16
> +- pclk-sample : (optional) (default: sample on falling edge)
Could you add that video-interfaces.txt contains documentation of these
properties as well? There's a reference above but only discusses port and
endpoint nodes.
> +- hsync-active : (only required for parallel)
> +- vsync-active : (only required for parallel)
As you support both Bt656 and parallel (with sync signals), you can detect
the interface type from the presence of these properties. I think you
should also say that these properties are not allowed on Bt656. So I'd
change this to e.g.
(required; parallel-only)
> +
> +Example:
> +
> +csi1: csi@1cb4000 {
> + compatible = "allwinner,sun8i-v3s-csi";
> + reg = <0x01cb4000 0x1000>;
> + interrupts = <GIC_SPI 84 IRQ_TYPE_LEVEL_HIGH>;
> + clocks = <&ccu CLK_BUS_CSI>,
> + <&ccu CLK_CSI1_SCLK>,
> + <&ccu CLK_DRAM_CSI>;
> + clock-names = "bus", "mod", "ram";
> + resets = <&ccu RST_BUS_CSI>;
> +
> + port {
> + /* Parallel bus endpoint */
> + csi1_ep: endpoint {
> + remote-endpoint = <&adv7611_ep>;
> + bus-width = <16>;
> +
> + /* If hsync-active/vsync-active are missing,
> + embedded BT.656 sync is used */
> + hsync-active = <0>; /* Active low */
> + vsync-active = <0>; /* Active low */
> + pclk-sample = <1>; /* Rising */
> + };
> + };
> +};
--
Kind regards,
Sakari Ailus
sakari.ailus@xxxxxxxxxxxxxxx
