edit file in codeigniter - php

Question

I have an error in my program it can't edit file. Where I var_dump($this->data[data]) data it found but not save in database
This is my controller
function edit_kegiatan($id='')
{
//set validation properties
$this->form_validation->set_rules('tanggal_kegiatan', 'Tanggal', 'required');
$this->form_validation->set_rules('nama_kegiatan', 'Judul Berita', 'required');
$this->form_validation->set_rules('content', 'Content', 'required');
$id = $this->uri->segment(4);
//run validation
// jika dia ingin update data atau form validation error
if ($this->form_validation->run() == true) {
$this->load->model('mkegiatan');
$config['upload_path'] = './images/';
$config['allowed_types'] = 'gif|jpg|png';
$config['max_size'] = '100000';
$config['max_width'] = '10240';
$config['max_height'] = '7680';
$this->load->library('upload', $config);
if ( ! $this->upload->do_upload('userfile'))
{
$error = array('error' => $this->upload->display_errors());
}
else
{
$data = array('upload_data' => $this->upload->data());
$datafoto=$this->upload->data();
$nm_file =$datafoto['file_name'];
$data = array(
'tanggal_kegiatan' => $this->input->post('tanggal_kegiatan'),
'nama_kegiatan' => $this->input->post('nama_kegiatan'),
'content' => $this->input->post('content'),
'image' => $nm_file
);
$this->mkegiatan->update_kegiatan($id,$data);
$this->session->set_flashdata('message', generateSuccessMessage('Data berhasil diupdate'));
redirect(site_url('admin/kegiatan'));
}
}
$this->data['orang'] = $this->mlogin->dataPengguna($this->session->userdata('username'));
$this->data['data'] = $this->mkegiatan->get_by_id($id);
$this->data['contents'] = $this->load->view('admin/kegiatan/edit_kegiatan', $this->data, true);
$this->load->view('template/wrapper/admin/wrapper_ukm',$this->data);
}
Any help appreciated.