загрузить несколько изображений с разными именами с помощью codeigniter

Просмотр файлов

<div class="row">
<div class="col-md-4 col-md-offset-4">
<form method="POST" action="<?php echo site_url('my-controller/file_upload');?>" enctype='multipart/form-data'>
<div class="form-group">
                    <label class="control-label">Mobile Image Front</label>
                    <input type="file" name="mobile_img[]" class="filestyle" data-placeholder="No file">
</div>
<div class="form-group">
                    <label class="control-label">Mobile Image Back</label>
                    <input type="file" name="mobile_img[]" class="filestyle" data-placeholder="No file">
</div>
<div class="form-group">
                    <label class="control-label">Mobile Image Side</label>
                    <input type="file" name="mobile_img[]" class="filestyle" data-placeholder="No file">
</div>
  <input type="submit" value="upload"></form>
</div>
</div>

Мой контроллер:

<?php
class My_Controller extends CI_Controller {
public function __construct() {
  parent::__construct();
  $this->load->library('upload');
}
public function file_upload(){
  $files = $_FILES;
  $cpt = count($_FILES['mobile_img']['name']);
  for($i=0; $i<$cpt; $i++)
  {
      $mobileView=(($i == 0)?"_front":(($i == 1)?"_back":"_side")); //Here i assign first image(i = 0) as _front, second image(i = 1) as _back,third image(i = 2) as _side
      $_FILES['mobile_img']['name']= $files['mobile_img']['name'][$i].$mobileView.time();// time() for time in seconds becauze we may need if same name uploaded file name
      $_FILES['mobile_img']['type']= $files['mobile_img']['type'][$i];
      $_FILES['mobile_img']['tmp_name']= $files['mobile_img']['tmp_name'][$i];
      $_FILES['mobile_img']['error']= $files['mobile_img']['error'][$i];
      $_FILES['mobile_img']['size']= $files['mobile_img']['size'][$i];
      $this->upload->initialize($this->set_upload_options());
      $this->upload->do_upload();
      $fileName = $_FILES['mobile_img']['name'];
      $images[] = $fileName;
  }
  $fileName = implode(',',$images);
  $this->my_model->upload_image($fileName);
}
private function set_upload_options()
{ 
// upload an image options
  $config = array();
  $config['upload_path'] = './upload/'; //give the path to upload the image in folder
  $config['allowed_types'] = 'gif|jpg|png';
  $config['max_size'] = '0';
  $config['overwrite'] = FALSE;
  return $config;
}
}
?>

Моя модель Функция:

<?php
class My_Model extends CI_Model {
public function upload_image($fileName)
{
    if($filename!='' ){
     $filename1 = explode(',',$filename);
      foreach($filename1 as $file){
           $file_data = array(
              'name' => $file,
              'datetime' => date('Y-m-d h:i:s')
              );
           $this->db->insert('uploaded_files', $file_data);
    }
 }
 }
}
?>