So now I have sms and voice working on FreePBX (Sangoma 7.5, kernel 3.10) with asterisk 15.7.0. To get it working I had to make some changes in chan_extra.c from chan_extra-2.0.8 source bundle. I attached it here in case this helps another people. TTY not working because it is a opvxg4xx driver issue (it crash kernel after enabling ttymode - tty part need some changes for recent kernels). I'll post it here if I can fix it.
All ifdefs are added against 15.0.0 version, so i'm pretty sure it doesn't compile for asterisk-13!
Ok. I made some changes in ovpxg4xx driver and now ttymode is ok and doesn't crash kernel on start/work.
But there is a problem with GSM710 mux mode. After start asterisk tries and tries to restart modules and detect them.
Muxed tty doesn't work too so I decided to use tty mode instead of mux and stop waisting time.