How to know the V4L2 camera's exposure time in ms?

with v4l2-ctl, one can know camera-parameters with following: $ v4l2-ctl -d2 --list-ctrls brightness 0x00980900 (int) : min=0 max=255 step=1 default=128 value=128 contrast 0x00980901 (int) : min=0 max=31 step=1 default=16 value=16 gamma 0x00980910 (int) : min=0 max=127 step=1 default=64 value=64 gain 0x00980913 (int) : min=1 max=33 step=1 default=0 value=33 power_line_frequency 0x00980918 (menu) : min=0 max=2 default=2 value=2 (60 Hz) sharpness 0x0098091b (int) : min=0 max=15 step=1 default=1 value=1 exposure_auto 0x009a0901 (menu) : min=0 max=3 default=3 value=1 (Manual Mode) exposure_absolute 0x009a0902 (int) : min=1 max=1856 step=1 default=2500 value=2500 I understand last one exposure_absolute is the exposure, but I'm not sure whether this is **always in ms**. Or some other unit (perhaps specific for each cam) that has to be converted to ms?