Wordpress function that displays tag cloud for specific post type

gistfile1.php

function pt_tag_cloud( $args = '' ) {
    $defaults = array(
        'smallest' => 8, 'largest' => 22, 'unit' => 'pt', 'number' => 45,
        'format' => 'flat', 'separator' => "\n", 'orderby' => 'name', 'order' => 'ASC',
        'exclude' => '', 'include' => '', 'link' => 'view', 'taxonomy' => 'post_tag', 'echo' => true,
    );
    $args = wp_parse_args( $args, $defaults );

    $post_type = $args['post_type'];
    global $wpdb;
    $tags = $wpdb->get_results(
        sprintf(
            "SELECT
            t.term_id,
            t.name,
            t.slug,
            t.term_group,
            t.term_order,
            t.menu_order,
            tt.term_taxonomy_id,
            tt.taxonomy,
            tt.description,
            tt.parent,
            COUNT(DISTINCT tr.object_id) AS count
            FROM {$wpdb->posts} p
            INNER JOIN {$wpdb->term_relationships} tr ON p.ID=tr.object_id
            INNER JOIN {$wpdb->term_taxonomy} tt ON tt.term_taxonomy_id=tr.term_taxonomy_id
            INNER JOIN {$wpdb->terms} t ON t.term_id=tt.term_id WHERE p.post_type='%s' AND p.post_status = 'publish' AND tt.taxonomy='post_tag' GROUP BY tt.term_taxonomy_id ORDER BY count DESC", $post_type) );

    if ( empty( $tags ) || is_wp_error( $tags ) )
        return;

    foreach ( $tags as $key => $tag ) {
        if ( 'edit' == $args['link'] )
            $link = get_edit_tag_link( $tag->term_id, $tag->taxonomy );
        else
            $link = get_term_link( intval($tag->term_id), $tag->taxonomy );
        if ( is_wp_error( $link ) ) {
            return false;
        }

        $tags[ $key ]->link = $link;
        $tags[ $key ]->id = $tag->term_id;
    }

    $return = wp_generate_tag_cloud( $tags, $args ); // Here's where those top tags get sorted according to $args

    $return = apply_filters( 'wp_tag_cloud', $return, $args );

    if ( 'array' == $args['format'] || empty($args['echo']) )
        return $return;

    echo $return;
}