Re: [PATCH v11 1/2] dt-bindings: media: Add Allwinner V3s Camera Sensor Interface (CSI)

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Yong,

Thank you for the patch.

On Wednesday, 26 September 2018 11:40:04 EEST Yong Deng wrote:
> Add binding documentation for Allwinner V3s CSI.
> 
> Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
> Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> Reviewed-by: Rob Herring <robh@kernel.org>
> Signed-off-by: Yong Deng <yong.deng@magewell.com>
> ---
>  .../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.

Nitpicking, BT.656 is parallel as well. We should use BT.601 instead of 
parallel, to differentiate between embedded sync and external sync. This is a 
problem in Documentation/devicetree/bindings/media/video-interfaces.txt in the 
first place, so I won't ask you to modify these bindings. I'll try to submit a 
patch for video-interfaces.txt.

> +Endpoint node properties for CSI1
> +---------------------------------

Should you list the CSI0 properties as well ? As the driver in patch 2/2 
doesn't support the CSI-2 interface I assume you have left out CSI0 for now, 
but it should still be listed in the bindings. I'm fine with fixing this as a 
follow-up patch to avoid missing the v4.20 merge window, but if you end up 
resubmitting the series, could you please address the problem ?

With this fixed,

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> +- 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)
> +- hsync-active		: (only required for parallel)
> +- vsync-active		: (only required for parallel)
>
> +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 */
> +		};
> +	};
> +};

-- 
Regards,

Laurent Pinchart