Well, rkisp1 driver that drives ISP on RK3399 on Pinephone Pro is available upstream in fully supported manner for like 4 years. It also has full docs in publicly available Rockchip datasheets and partial docs in calibration manuals.
What have people done with it? Some mediocre support in libcamera? :) I don't think lack of handholding is an issue here.
What have people done with it? Some mediocre support in libcamera? :) I don't think lack of handholding is an issue here.