Hi Sylwester,
On Thu, May 21, 2015 at 06:58:59PM +0200, Sylwester Nawrocki wrote:
> Hi Sakari,
>
> On 21/05/15 16:20, Sakari Ailus wrote:
> > On Thu, May 21, 2015 at 03:28:40PM +0200, Sylwester Nawrocki wrote:
> >> > On 21/05/15 13:32, Sakari Ailus wrote:
> >>>>>> > >>>> @@ -147,6 +149,8 @@ Example:
> >>>>>>>>> > >>>> > >> clocks = <&camera 0>;
> >>>>>>>>> > >>>> > >> clock-names = "mclk";
> >>>>>>>>> > >>>> > >>
> >>>>>>>>> > >>>> > >>+ samsung,flash-led = <&rear_cam_flash>;
> >>>>>>>>> > >>>> > >>+
> >>>>>>>>> > >>>> > >> port {
> >>>>>>>>> > >>>> > >> s5c73m3_1: endpoint {
> >>>>>>>>> > >>>> > >> data-lanes = <1 2 3 4>;
> >>>>>>> > >>> > >
> >>>>>>> > >>> > >Oops. I missed this property would have ended to the sensor's DT node. I
> >>>>>>> > >>> > >don't think we should have properties here that are parsed by another
> >>>>>>> > >>> > >driver --- let's discuss this tomorrow.
> >>>>> > >> >
> >>>>> > >> > exynos4-is driver already parses sensor nodes (at least their 'port'
> >>>>> > >> > sub-nodes).
> >>> > >
> >>> > > If you read the code and the comment, it looks like something that should be
> >>> > > done better but hasn't been done yet. :-) That's something we should avoid.
> >>> > > Also, flash devices are by far more common than external ISPs I presume.
> >> >
> >> > Yes, especially let's not require any samsung specific properties in
> >> > other vendors' sensor bindings.
> >> >
> >> > One way of modelling [flash led]/[image sensor] association I imagine
> >> > would be to put, e.g. 'flash-leds' property in the SoC camera host
> >> > interface/ISP DT node. This property would then contain pairs of phandles,
> >> > first to the led node and the second to the sensor node, e.g.
> >> >
> >> > i2c_controller {
> >> > ...
> >> > flash_xx@NN {
> >> > ...
> >> > led_a {
> >> > ...
> >> > }
> >> > };
> >> >
> >> > image_sensor_x@NN {
> >> > ...
> >> > };
> >> > };
> >> >
> >> > flash-leds = <&flash_xx &image_sensor_x>, <...>;
> >
> > Maybe a stupid question, but how do you access this in a driver? I have to
> > admit I'm no DT expert.
>
> You could get of_node pointers with of_parse_phandle() call and then
> lookup related flash and sensor devices based on that.
Ack. Looks good to me.
> >> > For the purpose of this patch set presumably just samsung specific
> >> > property name could be used (i.e. samsung,flash-leds).
> >
> > I agree. I'll add similar support for the omap3isp driver in the near future
> > though. Let's see how the camera modules will get modelled, if they will,
> > and if this property still fits to the picture by that time, then we make it
> > more generic.
> >
> > What do you think?
>
> I think we could do that, perhaps we could get some more opinions and
> use generic name already in this series? I'm not sure what are exact
> plans for this series, I guess it is targeted for 4.2?
There have been very few opinions expressed besides yours, mine and Jacek's,
unfortunately. I'm also not very certain on the future-proofness of this
solution until we have better understanding of how modules would best be
expressed in DT.
v4.2 would be nice target for these, yes.
--
Kind regards,
Sakari Ailus
e-mail: sakari.ailus@xxxxxx XMPP: sailus@xxxxxxxxxxxxxx
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