On Thu, Feb 2, 2017 at 1:05 AM, Sakari Ailus [off-list ref] wrote:

Hi Rob,

On Wed, Feb 01, 2017 at 10:50:59AM -0600, Rob Herring wrote:

quoted

quoted

+                   remote-endpoint = <&ov2640_0>;
+                   bus-width = <8>;
+                   vsync-active = <1>;
+                   hsync-active = <1>;

Which side of the connect is supposed to define these?

Today we have endpoint properties at each endpoint independently of the
remote endpoint. I guess you could obtain the endpoint properties from the
remote endpoint as well. There are exceptions though.

The constraints should be at whatever end is imposing them. 

The configuration might not always be exactly the same. The parallel
interface is a little bit special: you could conceivably have a transmitter
with 8 wires but a receiver that could only use 10 or more. The wiring could
be such that the two most significant bits of the transmitter would be wired
to the two least significant bits on the receiver side. In this case the
bus-width property would have different values at each endpoint.

Hopefully that implied wiring is documented somewhere.

If we were to do something like that, it should be done everywhere and such
exceptions be handled somehow.

The CSI-2 lane mapping configuration (where supported by the hardware) is
also specific to an endpoint.

--
Kind regards,

Sakari Ailus
e-mail: sakari.ailus@iki.fi     XMPP: sailus@retiisi.org.uk