The work required to get this one piece into mainline over 5-6 years reveals why most chip vendors aren’t aiming for mainline by default:
> A few iterations of the rkcif driver later, the basic driver providing support for the PX30 VIP and the RK3568 VICAP was accepted (October 2025). After more than five years of development, including 25 iterations and three renamings, this was a major milestone. On the other hand, there was still a lot to do, of course. For instance, the Rockchip MIPI CSI-2 receiver unit that is coupled closely to the VICAP required a mainline driver as well.
It’s never as simple as submitting existing work upstream and making a few changes. It takes a lot of development and a willingness to rewrite everything, possibly multiple times, to track the goals of upstream.
> It’s never as simple as submitting existing work upstream and making a few changes.
If they had started by working with upstream, then they wouldn't have to go through unnecessary revisions trying to adapt the thing they already wrote.
after working professionally with their stuff I'm really not a fan of Rockchip
There are chip providers that put more emphasis on mainline support but even those aren’t fully mainlined and their chips are generally much more expensive.
Software exists from the vendor, but it’s not open source and/or not part of Linux mainline.
Hence the effort to develop an open source (and mainlined) alternative.
Whether this is a good use of effort and/or whether you believe the vendor should be doing the Linux development or not, and:or whether they should open-source their proprietary drivers, will depend on your personal views.
So it might be too late as 3688 will be too hot...
Just like routers get dd-wrt when sold out!