2018-10-30 08:14:28

by Yong

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

Add binding documentation for Allwinner V3s CSI.

Acked-by: Maxime Ripard <[email protected]>
Acked-by: Sakari Ailus <[email protected]>
Reviewed-by: Rob Herring <[email protected]>
Signed-off-by: Yong Deng <[email protected]>
---
.../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



2018-10-30 13:10:25

by Laurent Pinchart

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

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 <[email protected]>
> Acked-by: Sakari Ailus <[email protected]>
> Reviewed-by: Rob Herring <[email protected]>
> Signed-off-by: Yong Deng <[email protected]>

Reviewed-by: Laurent Pinchart <[email protected]>

> ---
> .../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




2018-11-24 08:06:32

by jacopo mondi

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

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 <[email protected]>
> > Acked-by: Sakari Ailus <[email protected]>
> > Reviewed-by: Rob Herring <[email protected]>
> > Signed-off-by: Yong Deng <[email protected]>
>
> Reviewed-by: Laurent Pinchart <[email protected]>
>
> > ---
> > .../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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2018-11-24 08:08:31

by Yong

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

Hi jacopo,

On Fri, 23 Nov 2018 08:45:14 +0100
jacopo mondi <[email protected]> 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 <[email protected]>
> > > Acked-by: Sakari Ailus <[email protected]>
> > > Reviewed-by: Rob Herring <[email protected]>
> > > Signed-off-by: Yong Deng <[email protected]>
> >
> > Reviewed-by: Laurent Pinchart <[email protected]>
> >
> > > ---
> > > .../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

2018-11-24 08:09:10

by jacopo mondi

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

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 <[email protected]> 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 <[email protected]>
> > > > Acked-by: Sakari Ailus <[email protected]>
> > > > Reviewed-by: Rob Herring <[email protected]>
> > > > Signed-off-by: Yong Deng <[email protected]>
> > >
> > > Reviewed-by: Laurent Pinchart <[email protected]>
> > >
> > > > ---
> > > > .../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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2018-11-24 08:11:41

by Yong

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

Hi jacopo,

On Fri, 23 Nov 2018 09:13:00 +0100
jacopo mondi <[email protected]> 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 <[email protected]> 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 <[email protected]>
> > > > > Acked-by: Sakari Ailus <[email protected]>
> > > > > Reviewed-by: Rob Herring <[email protected]>
> > > > > Signed-off-by: Yong Deng <[email protected]>
> > > >
> > > > Reviewed-by: Laurent Pinchart <[email protected]>
> > > >
> > > > > ---
> > > > > .../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