Range values for V4L2_CID_* commands

[Lucas <lucasavdantas1992@xxxxxxxxx>]

Hello, how do I obtain the accepted range of values for each V4L2_CID 
command? Take V4L2_CID_BRIGHTNESS as an example, how do I know what is 
the maximum and minimum values accepted for it? I have tried to use 
'v4l2_ioctl(fd, VIDIOC_G_CTRL, &query);' thinking that would be stored 
in the maximum and minimum members for the struct v4l2_queryctrl but 
that does not appear to be the case as the values for those members are 
always zero.

Thank you.