How send data with ajaxFileUpload and codeigniter?

I tried to upload the data with ajax file upload and CodeIgniter, I get a problem, the file is successfully uploaded but failed to get value of the data, how to find a solution

<script type="text/javascript">
        $(function () {

            $("#upload_file").submit(function (event) {
                event.preventDefault();
                var formData = new FormData($(this)[0]);
                $.ajaxFileUpload({
                    url: '<?php echo base_url(); ?>upload/do_upload',
                    secureuri: false,
                    fileElementId: 'upload_doc',
                    dataType: 'json',
                    data: formData, 
                    success: function (data, status)
                    {
                        if (data.status == 'success')
                        {
                            alert(data.msg);
                        }

                    }
                });


                return false;
            });
        });</script>

and source codeigniter

function do_upload() {
    try {
        $pesan = "";
        $status = "";
        $file_element_name = "upload_doc";
        $id = $this->input->post('id', true); /* => failed to get data */
        if ($id == 0) {

            $config['upload_path'] = './files/';
            $config['allowed_types'] = 'pdf|docx|doc|txt';
            $config['max_size'] = 1024 * 8;
            $config['encrypt_name'] = TRUE;

            $this->load->library('upload', $config);
            if (!$this->upload->do_upload($file_element_name)) {
                $status = 'error';
                $msg = $this->upload->display_errors('', '');
            } else {
                $file = $this->upload->data();
                $isi['kd_upload'] = $this->mupload->autonumber_upload();
                $isi['tgl_upload'] = $this->fungsi_bebas->InggrisTgl($this->input->post('tgl_upload', true)); /* => failed to get data */
                $isi['nm_file'] = $file['file_name'];
                $isi['no_registrasi'] = $this->input->post('no_registrasi', true); /* => failed to get data */
                $isi['validasi'] = "validasi";


                $exe = $this->mupload->tambah_upload($isi);
                if ($exe > 0) {
                    $status = "success";
                    $pesan = "File successfully uploaded" ;

                } 
            }
        }
        echo json_encode(array('status' => $status, 'msg' => $pesan));
    } catch (Exception $exc) {

    }

reference : [http://ift.tt/1oeus6x]