Thanks for your answer Patrick,
You mentioned ipu, might be a type mistake. My issue deals with vpu. Whatever I look to ipu lib code and problem is the same..
Indeed, vpu_io.c handles device interface open/close/ioctl, but implementation of /dev/mxc_vpu is missing. That is that part of the kernel I'm interested in.
I found some sources on gitHub but can be sure it is reliable. I guess I can find "official" sources in Freescale package but I don't know where.