Re: [PATCH v5 0/5] Add OV5640 parallel interface and RGB565/YUYV support

On Thu, Jan 11, 2018 at 08:12:11AM +0000, Hugues FRUCHET wrote:

Hi Sakari,

On 01/10/2018 11:25 PM, Sakari Ailus wrote:

quoted

Hi Hugues,

On Wed, Jan 10, 2018 at 03:51:07PM +0000, Hugues FRUCHET wrote:

quoted

Good news Maxime !

Have you seen that you can adapt the polarities through devicetree ?

+                       /* Parallel bus endpoint */
+                       ov5640_to_parallel: endpoint {
[...]
+                               hsync-active = <0>;
+                               vsync-active = <0>;
+                               pclk-sample = <1>;
+                       };

Doing so you can adapt to your SoC/board setup easily.

If you don't put those lines in devicetree, the ov5640 default init
sequence is used which set the polarity as defined in below comment:
ov5640_set_stream_dvp()
[...]
+        * Control lines polarity can be configured through
+        * devicetree endpoint control lines properties.
+        * If no endpoint control lines properties are set,
+        * polarity will be as below:
+        * - VSYNC:     active high
+        * - HREF:      active low
+        * - PCLK:      active low
+        */
[...]

The properties are at the moment documented as mandatory in DT binding
documentation.

of course, it was just to ask Maxime to check the devicetree on its 
side, the symptom observed by Maxime with hsync/vsync inversed is the 
same than the one observed if we stick to just default init sequence.

I wonder if the driver should be changed to require hsync and vsync. These
signals won't be there at all in Bt.656 mode.

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