[PATCH RFC 2/2] dt-bindings: add binding documentation for Allwinner CSI

[Baruch Siach]

Hi Yong,

I am trying to get this driver working on the Olimex A33 OLinuXino. I didn't 
get it working yet, but I had some progress. See the comment below on one 
issue I encountered.

On Tue, Jun 27, 2017 at 07:07:34PM +0800, Yong Deng wrote:
> Add binding documentation for Allwinner CSI.
> 
> Signed-off-by: Yong Deng <yong.deng at magewell.com>
> ---
>  .../devicetree/bindings/media/sunxi-csi.txt        | 51 ++++++++++++++++++++++
>  1 file changed, 51 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/media/sunxi-csi.txt
> 
> diff --git a/Documentation/devicetree/bindings/media/sunxi-csi.txt b/Documentation/devicetree/bindings/media/sunxi-csi.txt
> new file mode 100644
> index 0000000..770be0e
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/media/sunxi-csi.txt
> @@ -0,0 +1,51 @@
> +Allwinner V3s Camera Sensor 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
> +    * ahb: 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
> +
> +- ports: A ports node with endpoint definitions as defined in
> +  Documentation/devicetree/bindings/media/video-interfaces.txt. The
> +  first port should be the input endpoints, the second one the outputs
> +
> +Example:
> +
> +	csi1: csi at 01cb4000 {
> +		compatible = "allwinner,sun8i-v3s-csi";
> +		reg = <0x01cb4000 0x1000>;

You use platform_get_resource_byname() to get this IO resource. This requires 
adding mandatory

  reg-names = "csi";

But is it actually needed? Wouldn't a simple platform_get_resource() be 
enough?

Thanks,
baruch

> +		interrupts = <GIC_SPI 84 IRQ_TYPE_LEVEL_HIGH>;
> +		clocks = <&ccu CLK_BUS_CSI>,
> +			 <&ccu CLK_CSI1_SCLK>,
> +			 <&ccu CLK_DRAM_CSI>;
> +		clock-names = "ahb", "mod", "ram";
> +		resets = <&ccu RST_BUS_CSI>;
> +
> +		port {
> +			#address-cells = <1>;
> +			#size-cells = <0>;
> +
> +			/* Parallel bus endpoint */
> +			csi1_0: endpoint at 0 {
> +				reg = <0>;
> +				remote = <&adv7611_1>;
> +				bus-width = <16>;
> +				data-shift = <0>;
> +
> +				/* If hsync-active/vsync-active are missing,
> +				   embedded BT.656 sync is used */
> +				hsync-active = <0>; /* Active low */
> +				vsync-active = <0>; /* Active low */
> +				data-active = <1>;  /* Active high */
> +				pclk-sample = <1>;  /* Rising */
> +			};
> +		};
> +	};
> +

-- 
     http://baruch.siach.name/blog/                  ~. .~   Tk Open Systems
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