I've just started using CHIRP and didn't find my radio supported. Searching the archives I've found Alan's driver and then Mark's C code in issue #2311. I've started to get it working and, I think I've got it to download reliably. I'm still having issues with decoding the data though.

So ... I'm attaching the code if you want to try it. 

Regards,

Benito

PS: Used this command to test it: ./chirpc -r Quansheng_TG-UV2 --download-mmap -s /dev/ttyUSB0 --mmap ./somefile.img