On Thu, Jan 11, 2018 at 08:25:41AM +0000, Hugues FRUCHET wrote:
> On 01/11/2018 09:19 AM, Sakari Ailus wrote:
> > 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:
> >>> Hi Hugues,
> >>>
> >>> On Wed, Jan 10, 2018 at 03:51:07PM +0000, Hugues FRUCHET wrote:
> >>>> 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.
> >
> I will revisit this when pushing Bt.656 mode.
That may lead to a situation where DT source which currently intends to use
parallel bus with sync signals will automatically switch to Bt.656. That
could be an issue for the receiver.
--
Sakari Ailus
e-mail: sakari.ailus@xxxxxx
