This source code is for the Geneis HTML5 “Return to Top” Tutorial article. In the original article, I included screen prints of the source and links to another site that has now become a paid membership site. This source code below is complete and will provide the Return to Top scrolling for Genesis HTML5 themes.
https://gist.github.com/vfontjr/c0d69fbb712f603ba1ed83732da50ffb#file-go_to_top-php