On Mon, 11 Apr 2011, Laurent Pinchart wrote: > Hi Javier, > > On Monday 11 April 2011 11:11:06 javier Martin wrote: > > Hi Laurent, > > > > > Adding pad-level operations will not break any existing driver, as long > > > as you keep the existing operations functional. > > > > Is it really possible to have a sensor driver supporting soc-camera, > > v4l2-subdev and pad-level operations? > > Probably. Guennadi should be able to help you some more with that, he's the > soc-camera expert. I'm afraid, I'm not sufficiently familiar with the (current state of) pad-level ops:-) I don't think, it is a very good idea to support two APIs in sensor drivers: pad-level for reuse with ISP and other compatible drivers and subdev / soc-camera for soc-camera hosts. I've tried pad-level ops as I played with the beagleboard-xM and an mt9p031 camera module. At that time to use the OMAP3 camera framework you had to use MC-aware applications. Standard V4L2 applications had no chance. I am not sure, whether this is a limitation of the ISP implementation or of the MC / pad APIs themselves. If this is still the case and if this backwards-compatible V4L2 mode is indeed difficult to implement with MC / pad, then soc-camera cannot migrate to that API atm. So, ideally, what should happen, I think, is the following: 1. we make sure, that the new APIs seamlessly support a "classic V4L2" fallback mode. 2. migrate (respective parts of) soc-camera to pad-level 3. enable driver reuse, for which, I think, two more things will have to be done: (a) create and switch to a unified way to pass driver platform data to subdev drivers (soc-camera is currently using struct soc_camera_link for this), (b) solve the bus configuration problem. > > I've been reviewing the code of mt9t112 and I'm not very sure soc-camera > > code can be easily isolated. > > > > What is the future of soc-camera anyway? Since it seems v4l2-subdev and > > media-controller clearly make it deprecated. > > My understanding is that soc-camera will stay, but sensor drivers will likely > not depend on soc-camera anymore. soc-camera will use pad-level operations, as > well as a bus configuration ioctl that has been proposed on the list (but not > finalized yet). Guennadi, can you share some information about this ? We want to reuse sensor drivers, yes:-) > > Wouldn't it be more suitable to just develop a separate mt9t112 driver > > which includes v4l2-subdev and pad-level operations without soc-camera? > > I don't think duplicate drivers will be accepted for mainline. +1 Thanks Guennadi --- Guennadi Liakhovetski, Ph.D. Freelance Open-Source Software Developer http://www.open-technology.de/ -- 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
