Hi Sylwester,

On Thursday 26 July 2012 21:51:30 Sylwester Nawrocki wrote:

On 07/26/2012 04:38 PM, Laurent Pinchart wrote:

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--- /dev/null
+++ b/Documentation/devicetree/bindings/video/mipi.txt

@@ -0,0 +1,5 @@
+Common properties of MIPI-CSI1 and MIPI-CSI2 receivers and

transmitters
+
+ - data-lanes : number of differential data lanes wired and actively
used in
+		communication between the transmitter and the receiver, this
+		excludes the clock lane;

Wouldn't it be better to use the standard "bus-width" DT property?

I can't see any problems with using "bus-width". It seems sufficient
and could indeed be better, without a need to invent new MIPI-CSI
specific names. That was my first RFC on that and my perspective
wasn't probably broad enough. :)

What about CSI receivers that can reroute the lanes internally ? We would
need to specify lane indices for each lane then, maybe with something
like

clock-lane =<0>;
data-lanes =<2 3 1>;

Sounds good to me. And the clock-lane could be made optional, as not all
devices would need it.

However, as far as I can see, there is currently no generic API for handling
this kind of data structure. E.g. number of cells for the "interrupts"
property is specified with an additional "#interrupt-cells" property.

It would have been much easier to handle something like:

data-lanes = <2>, <3>, <1>;

i.e. an array of the lane indexes.

I'm fine with that.

quoted

For receivers that can't reroute lanes internally, the data-lanes property
would be need to specify lanes in sequence.

data-lanes =<1 2 3>;

In this case we would be only interested in the number of cells in this
property, but how it could be retrieved ? With an array, it could have been
calculated from property length returned by of_property_find() (divided by
sizof(u32)).

Agreed.

-- 
Regards,

Laurent Pinchart