Re: [PATCH v6 1/2] media: i2c/ov5645: add the device tree binding document

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

Hi Todor,

On Friday 14 Oct 2016 15:01:08 Todor Tomov wrote:
> On 09/08/2016 03:22 PM, Laurent Pinchart wrote:
> > On Thursday 08 Sep 2016 12:13:54 Todor Tomov wrote:
> >> Add the document for ov5645 device tree binding.
> >> 
> >> Signed-off-by: Todor Tomov <todor.tomov@linaro.org>
> >> ---
> >> 
> >>  .../devicetree/bindings/media/i2c/ov5645.txt       | 52 ++++++++++++++++
> >>  1 file changed, 52 insertions(+)
> >>  create mode 100644
> >>  Documentation/devicetree/bindings/media/i2c/ov5645.txt
> >> 
> >> diff --git a/Documentation/devicetree/bindings/media/i2c/ov5645.txt
> >> b/Documentation/devicetree/bindings/media/i2c/ov5645.txt new file mode
> >> 100644
> >> index 0000000..bcf6dba
> >> --- /dev/null
> >> +++ b/Documentation/devicetree/bindings/media/i2c/ov5645.txt
> >> @@ -0,0 +1,52 @@
> >> +* Omnivision 1/4-Inch 5Mp CMOS Digital Image Sensor
> >> +
> >> +The Omnivision OV5645 is a 1/4-Inch CMOS active pixel digital image
> >> sensor with
> >> +an active array size of 2592H x 1944V. It is programmable through a
> >> serial I2C
> >> +interface.
> >> +
> >> +Required Properties:
> >> +- compatible: Value should be "ovti,ov5645".
> >> +- clocks: Reference to the xclk clock.
> >> +- clock-names: Should be "xclk".
> >> +- clock-frequency: Frequency of the xclk clock.
> >> +- enable-gpios: Chip enable GPIO. Polarity is GPIO_ACTIVE_HIGH.

By the way, isn't the pin called pwdnb and isn't it active low ?

> >> +- reset-gpios: Chip reset GPIO. Polarity is GPIO_ACTIVE_LOW.
> > 
> > Shouldn't the enable and reset GPIOs be optional ?
> 
> I don't think so. The operations on the GPIOs are part of the power up
> sequence of the sensor so we must have control over them to execute the
> exact sequence.

Right, let's keep them mandatory. If we later have to make them optional for a 
board that pulls one of those signals up (assuming this can work at all) we'll 
revisit the bindings.

> >> +- vdddo-supply: Chip digital IO regulator.
> >> +- vdda-supply: Chip analog regulator.
> >> +- vddd-supply: Chip digital core regulator.
> >> +
> >> +The device node must contain one 'port' child node for its digital
> >> output
> >> +video port, in accordance with the video interface bindings defined in
> >> +Documentation/devicetree/bindings/media/video-interfaces.txt.
> >> +
> >> +Example:
> >> +
> >> +	&i2c1 {
> >> +		...
> >> +
> >> +		ov5645: ov5645@78 {
> >> +			compatible = "ovti,ov5645";
> >> +			reg = <0x78>;
> >> +
> >> +			enable-gpios = <&gpio1 6 GPIO_ACTIVE_HIGH>;
> >> +			reset-gpios = <&gpio5 20 GPIO_ACTIVE_LOW>;
> >> +			pinctrl-names = "default";
> >> +			pinctrl-0 = <&camera_rear_default>;
> >> +
> >> +			clocks = <&clks 200>;
> >> +			clock-names = "xclk";
> >> +			clock-frequency = <23880000>;
> >> +
> >> +			vdddo-supply = <&camera_dovdd_1v8>;
> >> +			vdda-supply = <&camera_avdd_2v8>;
> >> +			vddd-supply = <&camera_dvdd_1v2>;
> >> +
> >> +			port {
> >> +				ov5645_ep: endpoint {
> >> +					clock-lanes = <1>;
> >> +					data-lanes = <0 2>;
> >> +					remote-endpoint = <&csi0_ep>;
> >> +				};
> >> +			};
> >> +		};
> >> +	};

-- 
Regards,

Laurent Pinchart