serialize open and close calls and ensure that device's
open and close methods are only called when first user
opens it or last user closes it.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!