WordPress Up to top button in footer

<?php
/**
 * @package WordPress
 * @subpackage Your Plugin or functions file
 * Up to top button in footer.
 */
add_action( 'wp_footer', 'swedest_footer_script_totop_button' );

function swedest_footer_script_totop_button()
{
	
    ob_start();	
	  echo '<div class="footer-upnav">
              <a href="#" title="^" class="btn btn-default align-xs-auto">
              <span class="footer-nav-caret">' . esc_html_e('^ Top/Pg.', 'scheduler') . '
              </span></a>
          </div>';
	  $html = ob_get_clean();
        echo $html;

}
/**
 * And now for the CSS which of course would not be in this function page
 */
.footer-nav-caret{
    background: rgba(0, 0, 0, .9);
    color:white;
    font-size:1em;
    text-align:center;
    padding:3px 5px;
}
.footer-upnav{
    float:right;
    position:relative;
    right:15px;
    top:0;
    z-index:998;
}