Hi Tomi, On Tuesday 07 October 2014 11:25:56 Tomi Valkeinen wrote: > On 07/10/14 10:23, Laurent Pinchart wrote: > >> You mean the bridge driver would somehow take a peek into panel1 and > >> panel2 nodes, looking for bridge specific properties? Sounds somewhat > >> fragile to me... How would the bridge driver know a property is for the > >> bridge? > > > > No, I mean the bridge driver should call the API provided by the panel > > objects to get information about the panels, and compute its > > configuration parameters from those. I'm not sure if that's possible > > though, it depends on whether the bridge parameters can be computed from > > information provided by the panel. > > Right. My example tried to show a case where they can't be queried. The > board or the wiring causes signal degradation, which can be fixed by > increasing the bridge output voltage slightly. > > So it has nothing really to do with the panel, but the board. > > I fully admit that it is a purely theoretical case, and I don't have any > real use cases in mind right now. Still, I agree with you that we might need to configure the bridge differently depending on the selected output with parameters that are not specific to the bridge. There's two use cases I can think of. In the first one the panels are connected directly to the bridge. The bridge should have two links from its output port, one to each panel. If we use the OF graph bindings then the bridge output port node would have two endpoint nodes, and configuration parameters can be stored in the endpoint nodes. In the second use case another element would be present between the bridge and the two panels. In that case there would be a single link between the bridge and that other element. If the bridge needs to be configured differently depending on the selected panel using parameters that can't be queried from the panels, then we'll have a problem. I'm not sure whether this use case has practical applications as board-related parameters seem to me that they pertain to physical links. -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
