Dunno for sure. Here are a few hypothesis. I could get updates for 
free from the kernel guy because I had his email, but my local dealer 
would probably have charged me for that and didn't care to keep me aware 
of upgrades.

     Also the API of their driver looked in contradiction with the one 
of Gabriel Paubert who has been developping a discontinued suite of free 
VME drivers for Debian. I talked with Gabriel Paubert more than a decade 
ago because I have been using his driver; it happened that we have 
completely different views on what VME is made for. Finally, a few years 
ago, a group devised a VME API for Linux every driver has to comply 
with, and Emerson followed the prescription. The API was very similar 
with the one of Paubert, but it also contained some absurdity, and, 
since my project was reaching the end, I just stopped upgrading the 
kernel and staid with version 2.6.27. The machines are still running 
Debian Wheezy with that old kernel.

     VME started in the 70's, and it has taken until ~ 5 years ago to 
have a VME API on Linux. In the mean time users have lived with vendor's 
BSPs. As a client, I didn't question the reason of all this; I made what 
I needed to get the job done.

     Didier