The device driver for the Canon Pixma TR4540 All-in-one Printer/Scanner does not come bundled with openSUSE, whether you are on Leap or Tumbleweed. It is non available from the official repositories as well, at least I didn't find them, neither on openSUSE Non-OSS or Packman repos.

However, Canon provides the drivers on its website along with an installation script. The tarball containing the the .rpm files and the script can be from its package-archive. At the time that I tested, the driver package was at version 5.70.

Extract the files.

tar xzvf cnijfilter2-5.70-1-rpm.tar.gz

Then, change in to the cnijfilter2-5.70-1-rpm directory and run the installation script as the root user.

cd cnijfilter2-5.70-1-rpm && sudo ./install

Finally, follow the on-screen (CLI) instructions to complete the setup.

That's it! Your Canon Pixma TR4540 setup should be complete & ready to use.