Hi Guennadi, On Wednesday 22 Feb 2017 18:54:20 Guennadi Liakhovetski wrote: > On Tue, 21 Feb 2017, Ajay kumar wrote: > > On Fri, Feb 17, 2017 at 7:27 PM, Thomas Axelsson wrote: > >> Hi, > >> > >> I have a v4l2_subdev that provides multiple MIPI CSI-2 Virtual > >> Channels. I want to configure each virtual channel individually (e.g. > >> set_fmt), but the v4l2 interface does not seem to have a clear way to > >> access configuration on a virtual channel level, but only the > >> v4l2_subdev as a whole. Using one v4l2_subdev for multiple virtual > >> channels by extending the "reg" tag to be an array looks like the > >> correct way to do it, based on the mipi-dsi-bus.txt document and > >> current device tree endpoint structure. > >> > >> However, I cannot figure out how to extend e.g. set_fmt/get_fmt subdev > >> ioctls to specify which virtual channel the call applies to. Does > >> anyone have any advice on how to handle this case? > > > > This would be helpful for my project as well since even I need to > > support multiple streams using Virtual Channels. > > Can anyone point out to some V4L2 driver, if this kind of support is > > already implemented? > > My understanding is, that MIPI CSI virtual channel handling requires > extensions to the V4L2 subdev API. These extensions have been discussed at > a media mini-summit almost a year ago, slides are available at [1], but as > my priorities shifted away from this work, don't think those extensions > ever got implemented. We've also discussed the topic last week in a face to face meeting with Niklas (CC'ed) and Sakari. Niklas will start working on upstreaming the necessary V4L2 API extensions for CSI-2 virtual channel support. The current plan is to start the work at the beginning of April. > [1] > https://linuxtv.org/downloads/presentations/media_summit_2016_san_diego/v4l > 2-multistream.pdf > > >> Previous thread: "Device Tree formatting for multiple virtual channels > >> in ti-vpe/cal driver?" > >> > >> Best Regards, > >> Thomas Axelsson > >> > >> PS. First e-mail seems to have gotten caught in the spam filter. I > >> apologize if this is a duplicate. -- Regards, Laurent Pinchart
