The current name is inconsistent with other driver model data access
functions. Rename it and fix up all users.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Joe Hershberger <joe.hershberger@ni.com>
Add some documentation describing how USB is implemented with USB. This
might make things easier for people to understand.
Signed-off-by: Simon Glass <sjg@chromium.org>