An Upstart job for BRLTTY can be found within the Autostart/Upstart/ subdirectory of BRLTTY's source tree. It's called brltty.conf. All you need to do is to copy this file into Upstart's jobs directory.
Upstart's jobs directory has changed over time. Older Upstart releases use /etc/event.d/ whereas newer ones use /etc/init/. You'll need to check your system to see which of these directories it's using. Don't get confused by the directory /etc/init.d/, which your system probably also has, and which has a similar name. It's used for something entirely different - SysV init scripts.
The file also needs to have the correct name. Older Upstart releases just use the job name itself, e.g. brltty, whereas newer ones append the .conf extension, e.g. brltty.conf.
So, to define BRLTTY's Upstart job, you'll need to do something like this:
For an older Upstart release:
cp brltty.conf /etc/event.d/brltty
For a newer Upstart release:
cp brltty.conf /etc/init/brltty.conf
Once the job file is in the right place, BRLTTY will automatically start when the system is rebooted. You'll also be able to use standard Upstart commands to manage the brltty job. The most common ones are:
status brltty start brltty stop brltty
For example: You don't need to reboot the system in order to start BRLTTY. Just use Upstart's start command to start it right away.