Custom footer with "back to top" link (customize and add to functions.php)

Custom Genesis footer with back to top link

// Custom Footer
add_filter('genesis_footer_output', 'footer_output_filter', 10, 3);

function footer_output_filter( $output, $backtotop_text, $creds_text ) {
    $backtotop_text = '[footer_backtotop text="Return to Top of Page"]';
    $creds_text = 'Copyright [footer_copyright] <a href="'. trailingslashit( get_bloginfo('url') ) .'" title="'. esc_attr( get_bloginfo('name') ) .' rel="nofollow"">'.get_bloginfo('name').'</a> &middot; Designed by <a href="http://www.nutsandboltsmedia.com" target="_blank" rel="nofollow">Nuts and Bolts Media</a>';
    $output = '<div class="gototop">' . $backtotop_text . '</div>' . '<div class="creds">' . $creds_text . '</div>';
      return $output;
}