Once you've sorted out the installation and have it working, you are encouraged to go to the main page and submit a probe of you complete configuration.
For many years I supported many users of that 'other' OS & had to ID many PCI devices - but now, as a Linux user for years I've never needed to do this before - stuff...always just worked !!
Thanks very much for those pointers;
Indeed I did not know of those sites & tools.
You're looking at a source code file from the Linux kernel. As @ugnvs pointed out, this module is likely already loaded, so you can use their command to check if the driver has been loaded. They also provided a link to some documentation which might help set the parallel ports up (although it is rather technical).
In case this helps in future:
Linux is designed such that drivers are 'part' of the kernel (often called a module - hence the tools modprobe, lsmod, etc for managing modules). There are, however, two types of driver - 'in tree' and 'out of tree'.
'In tree' means that the driver's code is part of the Linux kernel that everyone uses; which is the code you were looking at.
'Out of tree' means that the driver is not part of the kernel that everyone uses, and these are also called 'external modules'.
Obviously, the in-tree stuff works most of the time - you may find from time-to-time that an out-of-tree driver is needed. This is mainly for one of two reasons:
Regressions cause older hardware to fail on a newer kernel, so someone creates an out-of-tree driver for these cases.
Newer hardware hasn't been added to the kernel yet, so someone has created an out-of-tree driver to support it in the interim.
