$directory result Null in codeigniter - php

Question

I made a file upload in codeigniter, but in the controller I set $ directory = './assets/images/'; unreadable on vmware.
please help, here is my controller
public function tambahfotoproses()
{
$variable = 'foto'; //variable name dari form
$directory = './assets/images/'; //direktori
$allowed_file = 'gif|jpg|jpeg|png|JPG|GIF|PNG|JPEG'; //file yang diizinkan dibatasi dengan tanda
$upload['detail'] = $this->m_admin->uploadfile($variable,$directory,$allowed_file); //proses dengan modul insertfile
var_dump($upload); die();
/* to upload file */
$filename = $upload['detail']['file_name'];
if ($filename != "")
{
$data = array(
'foto' => $filename,
'person_nm' => $this->input->post('person_nm'),
'pengupload' => $this->input->post('pengupload'),
'tgl' => $this->input->post('tgl')
);
$insert = $this->db->insert('eregister_foto',$data);
} else {
$data = array(
'foto' => $filename,
'person_nm' => $this->input->post('person_nm'),
'pengupload' => $this->input->post('pengupload'),
'tgl' => $this->input->post('tgl')
);
$insert = $this->db->insert('eregister_foto',$data);
}
redirect('index.php/admin/foto_dr');
}
I deliberately gave var_dump () to find out the results of $ upload
the result is array (1) {["detail"] => int (0)}
photo not uploaded
and here is my modals.php
/AKSI UPLOAD FILE/
function uploadfile($var,$dir,$all){
$new_name = $this->input->post('person_nm');
$config2=array(
'image_library' => 'gd2',
'upload_path' => $dir."/dokter/", //lokasi gambar akan di simpan
'allowed_types' => $all, //ekstensi gambar yang boleh di unggah
'create_thumb' => TRUE,
'max_size' => '2048', //batas maksimal ukuran gambar
'file_name' => $new_name
);
$this->load->library('upload');
$this->upload->initialize($config2);
if ($this->upload->do_upload($var))
{
return $this->upload->data();
}
else
{
return 0;
}
}
i've try to rewrite folder "dokter" too, and still can't work