Carga de múltiples archivos en Codeigniter

Quiero cargar varios archivos usando un solo elemento. Así que pruebo este ejemplo.

Carga de múltiples archivos (Array) con CodeIgniter 2.0

este es mi formulario

<form enctype="multipart/form-data" class="jNice" accept-charset="utf-8" method="post" action="http://xxxx.dev/admin/add_estates">              
    <fieldset>      
            <label>Title * : </label>                       
            <input type="text" class="text-long" value="" name="title">

            <label>Description : </label>                       
            <textarea class="mceEditor" rows="10" cols="40" name="description"></textarea>

            <label>Image : </label>                     
            <input type="file" multiple="" name="images[]">                             

            <button class="button-submit" type="submit" name="save" id="">Save</button>
    </fieldset>         
</form>

este es mi controlador

public function add_estates()
{
    $data['page_title'] = "© IDEAL - Administrator - Real State - Add Real Estate";
    $data['main_content'] = 'admin/add_estates';

    if ($this->input->post() !== FALSE) {           
        $this->load->library('form_validation');
        $this->form_validation->set_rules('title', 'Career Title', 'trim|required');           

        if ($this->form_validation->run() !== FALSE) {                

            $title = $this->input->post('title');
            $description = $this->input->post('description');

            if (!empty($_FILES['images']['name'][0])) {
                if ($this->upload_files($title, $_FILES['images']) === FALSE) {
                    $data['error'] = $this->upload->display_errors('<div class="alert alert-danger">', '</div>');
                }
            }                   

            if (!isset($data['error'])) {
                $this->admin_model->add_estate($title, $description, $image_name);    
                $this->session->set_flashdata('suc_msg', 'New real estate added successfully'); 
                redirect('admin/add_estates');    
            }          
        }
    }

    $data['suc_msg'] = $this->session->flashdata('suc_msg');

    $this->load->view('layout_admin', $data);
}

Este es mi método de carga de archivos

private function upload_files($title, $files)
{
    $config = array(
        'upload_path'   => './upload/real_estate/',
        'allowed_types' => 'jpg|gif|png',
        'overwrite'     => 1,                       
    );

    $this->load->library('upload', $config);

    foreach ($files['name'] as $key => $image) {
        $_FILES['images']['name']= $files['name'][$key];
        $_FILES['images']['type']= $files['type'][$key];
        $_FILES['images']['tmp_name']= $files['tmp_name'][$key];
        $_FILES['images']['error']= $files['error'][$key];
        $_FILES['images']['size']= $files['size'][$key];

        $config['file_name'] = $title .'_'. $image;

        $this->upload->initialize($config);

        if ($this->upload->do_upload($image)) {
            $this->upload->data();
        } else {
            return false;
        }
    }

    return true;
}

pero da You did not select a file to upload. cada vez. ¿Cual es el problema?

Cambio el método de carga con images[] según @Dinamarca.

    private function upload_files($path, $title, $files)
    {
        $config = array(
            'upload_path'   => $path,
            'allowed_types' => 'jpg|gif|png',
            'overwrite'     => 1,                       
        );

        $this->load->library('upload', $config);

        $images = array();

        foreach ($files['name'] as $key => $image) {
            $_FILES['images[]']['name']= $files['name'][$key];
            $_FILES['images[]']['type']= $files['type'][$key];
            $_FILES['images[]']['tmp_name']= $files['tmp_name'][$key];
            $_FILES['images[]']['error']= $files['error'][$key];
            $_FILES['images[]']['size']= $files['size'][$key];

            $fileName = $title .'_'. $image;

            $images[] = $fileName;

            $config['file_name'] = $fileName;

            $this->upload->initialize($config);

            if ($this->upload->do_upload('images[]')) {
                $this->upload->data();
            } else {
                return false;
            }
        }

        return $images;
    }

Debe usar esta biblioteca para carga múltiple en CI
https://github.com/stvnthomas/CodeIgniter-Multi-Upload

public function index() {

    $user = $this->session->userdata("username");
    $file_path = "./images/" . $user . "https://stackoverflow.com/";

    if (isset($_FILES['multipleUpload'])) {

        if (!is_dir('images/' . $user)) {
            mkdir('./images/' . $user, 0777, TRUE);
        }

        $files = $_FILES;
        $cpt = count($_FILES ['multipleUpload'] ['name']);

        for ($i = 0; $i < $cpt; $i ++) {

            $name = time().$files ['multipleUpload'] ['name'] [$i];
            $_FILES ['multipleUpload'] ['name'] = $name;
            $_FILES ['multipleUpload'] ['type'] = $files ['multipleUpload'] ['type'] [$i];
            $_FILES ['multipleUpload'] ['tmp_name'] = $files ['multipleUpload'] ['tmp_name'] [$i];
            $_FILES ['multipleUpload'] ['error'] = $files ['multipleUpload'] ['error'] [$i];
            $_FILES ['multipleUpload'] ['size'] = $files ['multipleUpload'] ['size'] [$i];

            $this->upload->initialize($this->set_upload_options($file_path));
            if(!($this->upload->do_upload('multipleUpload')) || $files ['multipleUpload'] ['error'] [$i] !=0)
            {
                print_r($this->upload->display_errors());
            }
            else
            {
                $this->load->model('uploadModel','um');
                $this->um->insertRecord($user,$name);
            }
        }
    } else {
        $this->load->view('uploadForm');
    }
}

public function set_upload_options($file_path) {
    // upload an image options
    $config = array();
    $config ['upload_path'] = $file_path;
    $config ['allowed_types'] = 'gif|jpg|png';
    return $config;
}

private function upload_files($path, $title, $files)
{
    $config = array(
        'upload_path'   => $path,
        'allowed_types' => 'jpg|gif|png',
        'overwrite'     => 1,
    );

    $this->load->library('upload', $config);

    $images = array();

    foreach ($files['name'] as $key => $image) {
        $_FILES['images[]']['name']= $files['name'][$key];
        $_FILES['images[]']['type']= $files['type'][$key];
        $_FILES['images[]']['tmp_name']= $files['tmp_name'][$key];
        $_FILES['images[]']['error']= $files['error'][$key];
        $_FILES['images[]']['size']= $files['size'][$key];

        $fileName = $title .'_'. $image;

        $images[] = $fileName;

        $config['file_name'] = $fileName;

        $this->upload->initialize($config);

        if ($this->upload->do_upload('images[]')) {
            $this->upload->data();
        } else {
            return false;
        }
    }
    return true;
}