[PATCH v12 1/2] dt-bindings: media: Add Allwinner V3s Camera Sensor Interface (CSI)

[PATCH v12 1/2] dt-bindings: media: Add Allwinner V3s Camera Sensor Interface (CSI)

[Yong Deng]

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        | 56 ++++++++++++++++++++++
 1 file changed, 56 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..443e18c181b3
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/sun6i-csi.txt
@@ -0,0 +1,56 @@
+Allwinner V3s Camera Sensor Interface
+-------------------------------------
+
+Allwinner V3s SoC features a CSI module(CSI1) with 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
+
+The 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.
+
+Endpoint node properties for CSI
+---------------------------------
+See the video-interfaces.txt for a detailed description of these properties.
+- 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		: (required; parallel-only)
+- vsync-active		: (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 */
+		};
+	};
+};
-- 
1.8.3.1

Re: [PATCH v12 1/2] dt-bindings: media: Add Allwinner V3s Camera Sensor Interface (CSI)

[Laurent Pinchart]

Hi Yong,

Thank you for the patch.

On Tuesday, 30 October 2018 10:12:23 EET 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>

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

> ---
>  .../devicetree/bindings/media/sun6i-csi.txt        | 56 +++++++++++++++++++
>  1 file changed, 56 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..443e18c181b3
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/media/sun6i-csi.txt
> @@ -0,0 +1,56 @@
> +Allwinner V3s Camera Sensor Interface
> +-------------------------------------
> +
> +Allwinner V3s SoC features a CSI module(CSI1) with 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
> +
> +The 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.
> +
> +Endpoint node properties for CSI
> +---------------------------------
> +See the video-interfaces.txt for a detailed description of these
> properties. +- 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		: (required; parallel-only)
> +- vsync-active		: (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 */
> +		};
> +	};
> +};


-- 
Regards,

Laurent Pinchart

Re: [PATCH v12 1/2] dt-bindings: media: Add Allwinner V3s Camera Sensor Interface (CSI)

[jacopo mondi]

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Hi Yong,

On Tue, Oct 30, 2018 at 03:06:24PM +0200, Laurent Pinchart wrote:
> Hi Yong,
>
> Thank you for the patch.
>
> On Tuesday, 30 October 2018 10:12:23 EET 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>
>
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
>
> > ---
> >  .../devicetree/bindings/media/sun6i-csi.txt        | 56 +++++++++++++++++++
> >  1 file changed, 56 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..443e18c181b3
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/media/sun6i-csi.txt
> > @@ -0,0 +1,56 @@
> > +Allwinner V3s Camera Sensor Interface
> > +-------------------------------------
> > +
> > +Allwinner V3s SoC features a CSI module(CSI1) with 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
> > +
> > +The 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.
> > +
> > +Endpoint node properties for CSI
> > +---------------------------------
> > +See the video-interfaces.txt for a detailed description of these
> > properties. +- 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		: (required; parallel-only)
> > +- vsync-active		: (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 */

Am I confused? The properties description defines [v|h]sync-active as
required, but the example reports that they can be omitted to use
BT.656 synchronization.

Which one of the following is correct?
1) [h|v]sync-active are mandatory: no BT.656 support can be selected.
2) [h|v]sync-active are optional, and if not specified BT.656 is
   selected.
3) I am confused.

Thanks
   j

> > +			hsync-active = <0>; /* Active low */
> > +			vsync-active = <0>; /* Active low */
> > +			pclk-sample = <1>;  /* Rising */
> > +		};
> > +	};
> > +};
>
>
> --
> Regards,
>
> Laurent Pinchart
>
>
>

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Re: [PATCH v12 1/2] dt-bindings: media: Add Allwinner V3s Camera Sensor Interface (CSI)

[Yong]

Hi jacopo,

On Fri, 23 Nov 2018 08:45:14 +0100
jacopo mondi <jacopo@jmondi.org> wrote:

> Hi Yong,
> 
> On Tue, Oct 30, 2018 at 03:06:24PM +0200, Laurent Pinchart wrote:
> > Hi Yong,
> >
> > Thank you for the patch.
> >
> > On Tuesday, 30 October 2018 10:12:23 EET 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>
> >
> > Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> >
> > > ---
> > >  .../devicetree/bindings/media/sun6i-csi.txt        | 56 +++++++++++++++++++
> > >  1 file changed, 56 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..443e18c181b3
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/media/sun6i-csi.txt
> > > @@ -0,0 +1,56 @@
> > > +Allwinner V3s Camera Sensor Interface
> > > +-------------------------------------
> > > +
> > > +Allwinner V3s SoC features a CSI module(CSI1) with 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
> > > +
> > > +The 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.
> > > +
> > > +Endpoint node properties for CSI
> > > +---------------------------------
> > > +See the video-interfaces.txt for a detailed description of these
> > > properties. +- 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		: (required; parallel-only)
> > > +- vsync-active		: (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 */
> 
> Am I confused? The properties description defines [v|h]sync-active as
> required, but the example reports that they can be omitted to use
> BT.656 synchronization.
> 
> Which one of the following is correct?
> 1) [h|v]sync-active are mandatory: no BT.656 support can be selected.
> 2) [h|v]sync-active are optional, and if not specified BT.656 is
>    selected.
> 3) I am confused.
>
 
hsync-active		: (required; parallel-only)
vsync-active		: (required; parallel-only)

Here, parallel means seperate sync signal, BT.656 means embedded sync
signal. Kernel use these two properties to detect if the bus type is 
parallel or Bt656. So [h|v]sync-active are mandatory only if your bus
type is parallel and must not be specified if your bus type is Bt656.

Thanks,
Yong

Re: [PATCH v12 1/2] dt-bindings: media: Add Allwinner V3s Camera Sensor Interface (CSI)

[jacopo mondi]

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Hi Yong,

On Fri, Nov 23, 2018 at 04:01:17PM +0800, Yong wrote:
> Hi jacopo,
>
> On Fri, 23 Nov 2018 08:45:14 +0100
> jacopo mondi <jacopo@jmondi.org> wrote:
>
> > Hi Yong,
> >
> > On Tue, Oct 30, 2018 at 03:06:24PM +0200, Laurent Pinchart wrote:
> > > Hi Yong,
> > >
> > > Thank you for the patch.
> > >
> > > On Tuesday, 30 October 2018 10:12:23 EET 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>
> > >
> > > Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > >
> > > > ---
> > > >  .../devicetree/bindings/media/sun6i-csi.txt        | 56 +++++++++++++++++++
> > > >  1 file changed, 56 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..443e18c181b3
> > > > --- /dev/null
> > > > +++ b/Documentation/devicetree/bindings/media/sun6i-csi.txt
> > > > @@ -0,0 +1,56 @@
> > > > +Allwinner V3s Camera Sensor Interface
> > > > +-------------------------------------
> > > > +
> > > > +Allwinner V3s SoC features a CSI module(CSI1) with 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
> > > > +
> > > > +The 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.
> > > > +
> > > > +Endpoint node properties for CSI
> > > > +---------------------------------
> > > > +See the video-interfaces.txt for a detailed description of these
> > > > properties. +- 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		: (required; parallel-only)
> > > > +- vsync-active		: (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 */
> >
> > Am I confused? The properties description defines [v|h]sync-active as
> > required, but the example reports that they can be omitted to use
> > BT.656 synchronization.
> >
> > Which one of the following is correct?
> > 1) [h|v]sync-active are mandatory: no BT.656 support can be selected.
> > 2) [h|v]sync-active are optional, and if not specified BT.656 is
> >    selected.
> > 3) I am confused.
> >
>
> hsync-active		: (required; parallel-only)
> vsync-active		: (required; parallel-only)
>
> Here, parallel means seperate sync signal, BT.656 means embedded sync
> signal. Kernel use these two properties to detect if the bus type is
> parallel or Bt656. So [h|v]sync-active are mandatory only if your bus
> type is parallel and must not be specified if your bus type is Bt656.

Well, BT.565 sync mode applies to parallel data transmission busses as
BT.601 sync mode does... I don't want to bikeshed on terms though, I'm
sorry...

I would have write here:

hsync-active		: Required when using explicit HSYNC synchronism
                          signal. Default valuse is "high"/"low".
vsync-active		: Required when using explicit VSYNC synchronism
                          signal. Default valuse is "high"/"low".
When both vsync-active and hsync-active are omitted BT.565 implicit
synchronization mode is used.

To avoid confusing people already confused as I am :)

I got this patch is already in, right? Feel free to ignore my comment or
either send an incremental patch if you think it is appropriate.

Thanks
  j

> Thanks,
> Yong

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Re: [PATCH v12 1/2] dt-bindings: media: Add Allwinner V3s Camera Sensor Interface (CSI)

[Yong]

Hi jacopo,

On Fri, 23 Nov 2018 09:13:00 +0100
jacopo mondi <jacopo@jmondi.org> wrote:

> Hi Yong,
> 
> On Fri, Nov 23, 2018 at 04:01:17PM +0800, Yong wrote:
> > Hi jacopo,
> >
> > On Fri, 23 Nov 2018 08:45:14 +0100
> > jacopo mondi <jacopo@jmondi.org> wrote:
> >
> > > Hi Yong,
> > >
> > > On Tue, Oct 30, 2018 at 03:06:24PM +0200, Laurent Pinchart wrote:
> > > > Hi Yong,
> > > >
> > > > Thank you for the patch.
> > > >
> > > > On Tuesday, 30 October 2018 10:12:23 EET 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>
> > > >
> > > > Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > > >
> > > > > ---
> > > > >  .../devicetree/bindings/media/sun6i-csi.txt        | 56 +++++++++++++++++++
> > > > >  1 file changed, 56 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..443e18c181b3
> > > > > --- /dev/null
> > > > > +++ b/Documentation/devicetree/bindings/media/sun6i-csi.txt
> > > > > @@ -0,0 +1,56 @@
> > > > > +Allwinner V3s Camera Sensor Interface
> > > > > +-------------------------------------
> > > > > +
> > > > > +Allwinner V3s SoC features a CSI module(CSI1) with 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
> > > > > +
> > > > > +The 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.
> > > > > +
> > > > > +Endpoint node properties for CSI
> > > > > +---------------------------------
> > > > > +See the video-interfaces.txt for a detailed description of these
> > > > > properties. +- 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		: (required; parallel-only)
> > > > > +- vsync-active		: (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 */
> > >
> > > Am I confused? The properties description defines [v|h]sync-active as
> > > required, but the example reports that they can be omitted to use
> > > BT.656 synchronization.
> > >
> > > Which one of the following is correct?
> > > 1) [h|v]sync-active are mandatory: no BT.656 support can be selected.
> > > 2) [h|v]sync-active are optional, and if not specified BT.656 is
> > >    selected.
> > > 3) I am confused.
> > >
> >
> > hsync-active		: (required; parallel-only)
> > vsync-active		: (required; parallel-only)
> >
> > Here, parallel means seperate sync signal, BT.656 means embedded sync
> > signal. Kernel use these two properties to detect if the bus type is
> > parallel or Bt656. So [h|v]sync-active are mandatory only if your bus
> > type is parallel and must not be specified if your bus type is Bt656.
> 
> Well, BT.565 sync mode applies to parallel data transmission busses as
> BT.601 sync mode does... I don't want to bikeshed on terms though, I'm
> sorry...
> 
> I would have write here:
> 
> hsync-active		: Required when using explicit HSYNC synchronism
>                           signal. Default valuse is "high"/"low".
> vsync-active		: Required when using explicit VSYNC synchronism
>                           signal. Default valuse is "high"/"low".
> When both vsync-active and hsync-active are omitted BT.565 implicit
> synchronization mode is used.
> 
> To avoid confusing people already confused as I am :)
> 
> I got this patch is already in, right? Feel free to ignore my comment or
> either send an incremental patch if you think it is appropriate.
> 

As Laurent's mentioned in this thread, this is a problem in 
Documentation/devicetree/bindings/media/video-interfaces.txt in the 
first place. And he said he'll try to submit a patch for 
video-interfaces.txt.

Thanks,
Yong