diff mbox

[v4,2/3] media: ov7740: Document device tree bindings

Message ID 20171031011146.6899-3-wenyou.yang@microchip.com (mailing list archive)
State Superseded, archived
Delegated to: Sakari Ailus
Headers

Commit Message

Wenyou Yang Oct. 31, 2017, 1:11 a.m. UTC 
  Add the device tree binding documentation for the ov7740 sensor driver.

Signed-off-by: Wenyou Yang <wenyou.yang@microchip.com>
---

Changes in v4: None
Changes in v3:
 - Explicitly document the "remote-endpoint" property.

Changes in v2: None

 .../devicetree/bindings/media/i2c/ov7740.txt       | 47 ++++++++++++++++++++++
 1 file changed, 47 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/media/i2c/ov7740.txt

Comments

Rob Herring Nov. 1, 2017, 9:51 p.m. UTC | #1 
On Tue, Oct 31, 2017 at 09:11:44AM +0800, Wenyou Yang wrote:
> Add the device tree binding documentation for the ov7740 sensor driver.
> 
> Signed-off-by: Wenyou Yang <wenyou.yang@microchip.com>
> ---
> 
> Changes in v4: None
> Changes in v3:
>  - Explicitly document the "remote-endpoint" property.
> 
> Changes in v2: None
> 
>  .../devicetree/bindings/media/i2c/ov7740.txt       | 47 ++++++++++++++++++++++
>  1 file changed, 47 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/media/i2c/ov7740.txt
> 
> diff --git a/Documentation/devicetree/bindings/media/i2c/ov7740.txt b/Documentation/devicetree/bindings/media/i2c/ov7740.txt
> new file mode 100644
> index 000000000000..af781c3a5f0e
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/media/i2c/ov7740.txt
> @@ -0,0 +1,47 @@
> +* Omnivision OV7740 CMOS image sensor
> +
> +The Omnivision OV7740 image sensor supports multiple output image
> +size, such as VGA, and QVGA, CIF and any size smaller. It also
> +supports the RAW RGB and YUV output formats.
> +
> +The common video interfaces bindings (see video-interfaces.txt) should
> +be used to specify link to the image data receiver. The OV7740 device
> +node should contain one 'port' child node with an 'endpoint' subnode.
> +
> +Required Properties:
> +- compatible:	"ovti,ov7740".
> +- reg:		I2C slave address of the sensor.
> +- clocks:	Reference to the xvclk input clock.
> +- clock-names:	"xvclk".
> +
> +Optional Properties:
> +- reset-gpios: Rreference to the GPIO connected to the reset_b pin,
> +  if any. Active low with pull-ip resistor.
> +- powerdown-gpios: Reference to the GPIO connected to the pwdn pin,
> +  if any. Active high with pull-down resistor.
> +
> +Endpoint node mandatory properties:
> +- remote-endpoint: A phandle to the bus receiver's endpoint node.

This is not really necessary. What's required is documenting how many 
ports and how many endpoints for each port which you have above.

Acked-by: Rob Herring <robh@kernel.org>
Sakari Ailus Nov. 3, 2017, 11:43 a.m. UTC | #2 
Hi Rob,

On Wed, Nov 01, 2017 at 04:51:57PM -0500, Rob Herring wrote:
> On Tue, Oct 31, 2017 at 09:11:44AM +0800, Wenyou Yang wrote:
> > Add the device tree binding documentation for the ov7740 sensor driver.
> > 
> > Signed-off-by: Wenyou Yang <wenyou.yang@microchip.com>
> > ---
> > 
> > Changes in v4: None
> > Changes in v3:
> >  - Explicitly document the "remote-endpoint" property.
> > 
> > Changes in v2: None
> > 
> >  .../devicetree/bindings/media/i2c/ov7740.txt       | 47 ++++++++++++++++++++++
> >  1 file changed, 47 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/media/i2c/ov7740.txt
> > 
> > diff --git a/Documentation/devicetree/bindings/media/i2c/ov7740.txt b/Documentation/devicetree/bindings/media/i2c/ov7740.txt
> > new file mode 100644
> > index 000000000000..af781c3a5f0e
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/media/i2c/ov7740.txt
> > @@ -0,0 +1,47 @@
> > +* Omnivision OV7740 CMOS image sensor
> > +
> > +The Omnivision OV7740 image sensor supports multiple output image
> > +size, such as VGA, and QVGA, CIF and any size smaller. It also
> > +supports the RAW RGB and YUV output formats.
> > +
> > +The common video interfaces bindings (see video-interfaces.txt) should
> > +be used to specify link to the image data receiver. The OV7740 device
> > +node should contain one 'port' child node with an 'endpoint' subnode.
> > +
> > +Required Properties:
> > +- compatible:	"ovti,ov7740".
> > +- reg:		I2C slave address of the sensor.
> > +- clocks:	Reference to the xvclk input clock.
> > +- clock-names:	"xvclk".
> > +
> > +Optional Properties:
> > +- reset-gpios: Rreference to the GPIO connected to the reset_b pin,
> > +  if any. Active low with pull-ip resistor.
> > +- powerdown-gpios: Reference to the GPIO connected to the pwdn pin,
> > +  if any. Active high with pull-down resistor.
> > +
> > +Endpoint node mandatory properties:
> > +- remote-endpoint: A phandle to the bus receiver's endpoint node.
> 
> This is not really necessary. What's required is documenting how many 
> ports and how many endpoints for each port which you have above.

I actually requested adding that as the practice, as far as I've understood
it, has been to document all properties relevant for the hardware (apart
from things such as assigned-clocks etc.).

The port and endpoints have been elaborated above and I think that should
be fine as-is.

The graph bindings document (referred by video-interfaces.txt) the
remote-endpoint property in an endpoint as an optional property, however
you can't really use the sensor if it's not connected to anything. The same
goes for video-interfaces.txt: remote-endpoint in an endpoint is optional.

I have no objections removing remote-endpoint here, though, if you think
it's not relevant here.
diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/media/i2c/ov7740.txt b/Documentation/devicetree/bindings/media/i2c/ov7740.txt
new file mode 100644
index 000000000000..af781c3a5f0e
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/i2c/ov7740.txt
@@ -0,0 +1,47 @@ 
+* Omnivision OV7740 CMOS image sensor
+
+The Omnivision OV7740 image sensor supports multiple output image
+size, such as VGA, and QVGA, CIF and any size smaller. It also
+supports the RAW RGB and YUV output formats.
+
+The common video interfaces bindings (see video-interfaces.txt) should
+be used to specify link to the image data receiver. The OV7740 device
+node should contain one 'port' child node with an 'endpoint' subnode.
+
+Required Properties:
+- compatible:	"ovti,ov7740".
+- reg:		I2C slave address of the sensor.
+- clocks:	Reference to the xvclk input clock.
+- clock-names:	"xvclk".
+
+Optional Properties:
+- reset-gpios: Rreference to the GPIO connected to the reset_b pin,
+  if any. Active low with pull-ip resistor.
+- powerdown-gpios: Reference to the GPIO connected to the pwdn pin,
+  if any. Active high with pull-down resistor.
+
+Endpoint node mandatory properties:
+- remote-endpoint: A phandle to the bus receiver's endpoint node.
+
+Example:
+
+	i2c1: i2c@fc028000 {
+		ov7740: camera@21 {
+			compatible = "ovti,ov7740";
+			reg = <0x21>;
+			pinctrl-names = "default";
+			pinctrl-0 = <&pinctrl_sensor_power &pinctrl_sensor_reset>;
+			clocks = <&isc>;
+			clock-names = "xvclk";
+			assigned-clocks = <&isc>;
+			assigned-clock-rates = <24000000>;
+			reset-gpios = <&pioA 43 GPIO_ACTIVE_LOW>;
+			powerdown-gpios = <&pioA 44 GPIO_ACTIVE_HIGH>;
+
+			port {
+				ov7740_0: endpoint {
+					remote-endpoint = <&isc_0>;
+				};
+			};
+		};
+	};