I'm working on a piece of software that'll be released as a dll under LGPL. The software interfaces with hardware from a small company that has provided me with the needed libraries and some code to use them correctly (not only headers but its all in a separate file). As far as i know, the same code is used in their proprietary software that they don't intend to open source but they'd be fine releasing the piece of code they've given me.
Now here's the question:
What license could be used on the code I got from the company? I guess using GPL or LGPL would make them violate GPL when using the same code in their other software.
Is MIT a good idea? Is it ok to just include a file with MIT license on it in my otherwise LGPL:ed project?
Since I'm not the copyright holder, I'd have to ask the company to apply the license obviously but that shouldn't be a problem.