raspberrypi inclusion
category: feature
bugzilla: 50432

--------------------------------

Add support for very long exposures by using the exposure multiplier
register. Userland does not need to pass any additional controls to
enable long exposures, it simply requests a larger vblank to extend the
exposure control range appropriately.

Currently, since hblank is fixed, a maximum of approximately 124 seconds
of exposure time can be used. In a future change, hblank could also be
controlled in userland to give over 200 seconds of exposure time.
Signed-off-by: NNaushir Patuck <naush@raspberrypi.com>
Signed-off-by: NFang Yafen <yafen@iscas.ac.cn>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>