Re: [PATCH v5 1/4] dt-bindings: media: Add bindings for OV5695

Hi Shunqian,

On Thu, Jan 11, 2018 at 02:44:33PM +0800, Shunqian Zheng wrote:

Hi Jacopo,


On 2018年01月10日 17:20, jacopo mondi wrote:

quoted

Hi Shunqian,

On Wed, Jan 10, 2018 at 10:06:04AM +0800, Shunqian Zheng wrote:

quoted

Add device tree binding documentation for the OV5695 sensor.

Signed-off-by: Shunqian Zheng <redacted>
---
  .../devicetree/bindings/media/i2c/ov5695.txt       | 41 ++++++++++++++++++++++
  1 file changed, 41 insertions(+)
  create mode 100644 Documentation/devicetree/bindings/media/i2c/ov5695.txt

diff --git a/Documentation/devicetree/bindings/media/i2c/ov5695.txt b/Documentation/devicetree/bindings/media/i2c/ov5695.txt
new file mode 100644
index 0000000..2f2f698
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/i2c/ov5695.txt

@@ -0,0 +1,41 @@
+* Omnivision OV5695 MIPI CSI-2 sensor
+
+Required Properties:
+- compatible: shall be "ovti,ov5695"
+- clocks: reference to the xvclk input clock
+- clock-names: shall be "xvclk"
+- avdd-supply: Analog voltage supply, 2.8 volts
+- dovdd-supply: Digital I/O voltage supply, 1.8 volts
+- dvdd-supply: Digital core voltage supply, 1.2 volts
+- reset-gpios: Low active reset gpio
+
+The device node shall contain one 'port' child node with an
+'endpoint' subnode for its digital output video port,
+in accordance with the video interface bindings defined in
+Documentation/devicetree/bindings/media/video-interfaces.txt.
+The endpoint optional property 'data-lanes' shall be "<1 2>".

What happens if the property is not present? What's the default?

I think it depends on how the video receiver deal with, 'data-lanes' is
optional as described in video-interfaces.txt,
but if somehow it used in DT, the value "<1 2>" is the right one.

They're described as optional there as they may not be mandated for all
devices --- they're only relevant for some.

The data-lanes property also specifies the number of lanes. I guess you
could say two is default. The device can likely be configured to just use
one, even if the driver doesn't support it.

-- 
Sakari Ailus
e-mail: sakari.ailus-X3B1VOXEql0@public.gmane.org
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