Hi Hans, On Tuesday 14 December 2010 15:51:08 Hans Verkuil wrote: > > Laurent Pinchart wrote: > >> On Monday 13 December 2010 17:10:51 Clemens Ladisch wrote: > >>> TYPE_EXT describes entities that represent some interface to the > >>> external world, TYPE_INT those that are internal to the entire device. > >>> (I'm not sure if that distinction is very useful, but TYPE_SUBDEV seems > >>> to be an even more meaningless name.) > >> > >> SUBDEV comes from the V4L2 world, and I agree that it might not be a > >> very good > >> name. > >> > >> I'm not sure I would split entities in internal/external categories. I > >> would > >> create a category for connectors though. > > > > I'm not disagreeing, but what is actually the distinction between types > > and subtypes? ;-) > > The type tells what the behavior is of an entity. E.g., type DEVNODE > represents device node(s) in userspace, V4L2_SUBDEV represents a v4l2 > sub-device, etc. The subtype tells whether a V4L2_SUBDEV is a sensor or a > receiver or whatever. Nice to know, but it doesn't change the way > sub-devices work. > > In the case of connectors you would create a CONNECTOR type and have a > bunch of subtypes for all the variations of connectors. > > That said, I'm not sure whether the distinction is useful for DEVNODEs. > You do need to know the subtype in order to interpret the union correctly. > > Laurent, does the MC code test against the DEVNODE type? I.e., does the MC > code ignore the subtype of a DEVNODE, or does it always use it? The MC code uses the DEVNODE type, ignoring the subtype, for power management. When a device node is opened all entities in the chain need to be powered up. -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
