Please reference to the reference driver …/kernel/driver/i2c/ov5693.c to pass the v4l2-ctl/v4l2-compliance test first. You can also find how to implement you devices tree there.
And for regulator you have to make sure your hardware need to enable it. Also if your HW are always power on then you don’t need to struggle on the regulator.
Please download the document from below link and reference to the “Sensor Driver Programming Guide” chapter
http://developer.nvidia.com/embedded/dlc/l4t-documentation-24-2