Hi Laurent, On Tue, May 10, 2011 at 5:51 PM, Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> wrote: > Hi, > > On Tuesday 10 May 2011 08:14:10 Hans Verkuil wrote: >> > On Tue, May 10, 2011 at 5:42 AM, Laurent Pinchart wrote: >> >>> >> Why is there no enum_input operation in v4l2_subdev_video_ops? >> >> >> >> Why do you need one ? >> > >> > Because I want to query decoder how many inputs it can support. >> > So the question is where we should store inputs info, board specific data >> > or decoder driver? >> > I appreciate your advice. >> >> ENUMINPUT as defined by V4L2 enumerates input connectors available on the >> board. Which inputs the board designer hooked up is something that only >> the top-level V4L driver will know. Subdevices do not have that >> information, so enuminputs is not applicable there. >> >> Of course, subdevices do have input pins and output pins, but these are >> assumed to be fixed. With the s_routing ops the top level driver selects >> which input and output pins are active. Enumeration of those inputs and >> outputs wouldn't gain you anything as far as I can tell since the >> subdevice simply does not know which inputs/outputs are actually hooked >> up. It's the top level driver that has that information (usually passed in >> through board/card info structures). > > I agree. Subdevs don't have enough knowledge of their surroundings to make > input enumeration really useful. They could enumerate their input pins, but > not the inputs that are actually hooked up on board. > > The media controller framework is one way of solving this issue. It can report > links for every input pad. > > Scott, can you tell us a bit more about the decoder you're working with ? What > kind of system is it used in ? I'm working on ADV7183 and VS6624 connecting with blackfin through ppi. By the way, ppi is a generic parallel interface, that means it can't know the fmt supported itself. Should I use enum_mbus_fmt to ask decoder for this info? I found it in v4l2_subdev_video_ops, but didn't know its usage exactly. Regards, Scott -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
