Hi, Sakari! On 2024-10-11 at 10:55 +03, Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx> wrote: > Hello everyone, > > I've been recently working (with others) on sub-device streams support as > well as on internal pads. The two can be used to make sub-device > configuration more versatile. > > At the same time, the added interfaces are much more useful if we require > specific semantics of those interfaces, so that the user space knows > exactly what e.g. a given selection target signifies. However, as the same > selection rectangle could be used for a different purpose on a non-raw > sensor device, we need a way to tell how should the user space determine > how to use a given interface. > > I'm proposing to solve this problem by introducing sub-device > configuration models, and by the common raw sensor model, also present in > this patchset, in particular. > > This has been (and will, for some time, continue to be) the reason why I > have reviewed few sensor driver related patches lately. As we're > introducing a new interface, it's beneficial to be able to use that > interface right from the start, rather than trying to later on offer > compatibility support, which is almost always a fair amount of work with > less than desirable results in the driver. > > With this solved, I believe we can enable the use of the streams UAPI. > > Comments are welcome. > > The compiled documentation can be found in > <URL:https://www.retiisi.eu/~sailus/v4l2/tmp/meta-format/output/userspace-api/media/v4l/dev-subdev.html#sub-device-configuration-models> > and the patches here > <URL:https://git.linuxtv.org/sailus/media_tree.git/log/?h=metadata>, i.e. > they're on top of the metadata set. I've read the updated documentation you shared, and have a question concerning binning configuration. IIUC binning should be configured via set_selection(V4L2_SEL_TGT_COMPOSE). But I also see some existing drivers configure binning via set_fmt() (imx296) or both set_fmt() and set_selection(V4L2_SEL_TGT_COMPOSE) (imx274). What will be the right way to add binning support to a driver I care about (ov4689), which presently does not implement any binning configuration at all? -- Best regards, Mikhail
