uploading file not working in codeigniter 3 error: you did not select any file

 'zip'  =>  array('application/x-zip', 'application/zip', 'application/x-zip-compressed','application/force-download','application/octet-stream'),
 'rar'  =>  array('application/x-rar', 'application/rar','application/x-rar-compressed','application/force-download','application/octet-stream'),

$this->upload->do_upload()

$this->upload->do_upload($field_name)

 function importcsv() {

        $data['addressbook'] = $this->csv_model->get_addressbook();
        $data['error'] = '';    //initialize image upload error array to empty

    $this->form_validation->set_rules('uploaded_file','Uploaded file', 'trim|callback_chk_attachment');

        if($this->form_validation->run()){    
        $config['upload_path'] = './uploads/';
        $config['allowed_types'] = '*';
        $config['max_size'] = '1000';

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

        // If upload failed, display error
        if (!$this->upload->do_upload()) {
            $data['error'] = $this->upload->display_errors();

            $this->load->view('csvindex', $data);
        } else {
            $file_data = $this->upload->data();
            $file_path =  './uploads/'.$file_data['file_name'];

            if ($this->csvimport->get_array($file_path)) {
                $csv_array = $this->csvimport->get_array($file_path);
                foreach ($csv_array as $row) {
                    $insert_data = array(
                        'firstname'=>$row['firstname'],
                        'lastname'=>$row['lastname'],
                        'phone'=>$row['phone'],
                        'email'=>$row['email'],
                    );
                    $this->csv_model->insert_csv($insert_data);
                }
                $this->session->set_flashdata('success', 'Csv Data Imported Succesfully');
                redirect(base_url().'csv');
                //echo "<pre>"; print_r($insert_data);
            } else 
                $data['error'] = "Error occured";
                $this->load->view('csvindex', $data);
            }

        }




Call Back function for File Upload validation:

        public function chk_attachment() // callback validation for check the attachment extension
        {
            $file_type = array('.csv');
            if(!empty($_FILES['uploaded_file']['name']))
            {
                $ext = strtolower(strrchr($_FILES['uploaded_file']['name'],"."));
                if(in_array($ext,$ext_array))
                {
                    return true;
                }
                else
                {
                    $this->form_validation->set_message('chk_attachment','Attachment allowed only csv');
                    return false;
                }
            }
            {
               $this->form_validation->set_message('chk_attachment','image field is required');
                    return false;
            }
        }

public function uploadImage() {
        $this->load->helper(array('form', 'url'));  
        $config['upload_path'] = 'assets/images/b2bcategory';
        $config['allowed_types'] = 'gif|jpg|png';
        $config['max_size'] = '1000';
        $config['max_width'] = '2024';
        $config['max_height'] = '1768';
        $config['width'] = 75;
        $config['height'] = 50;
        if (isset($_FILES['catimage']['name'])) {
            $filename = "-" . $_FILES['catimage']['name'];
            $config['file_name'] = substr(md5(time()), 0, 28) . $filename;
        }
        $config['overwrite'] = TRUE;
        $config['remove_spaces'] = TRUE;
        $field_name = "catimage";
        $this->load->library('upload', $config);
        if ($this->input->post('selsub')) {
            if (!$this->upload->do_upload('catimage')) {
                //no file uploaded or failed upload
                $error = array('error' => $this->upload->display_errors());
            } else {
                $dat = array('upload_data' => $this->upload->data());
                $this->resize($dat['upload_data']['full_path'],           $dat['upload_data']['file_name']);
            }
            $ip = $_SERVER['REMOTE_ADDR'];
            if (empty($dat['upload_data']['file_name'])) {
                $catimage = '';
            } else {
                $catimage = $dat['upload_data']['file_name'];
            }
            $data = array(            
                'ctg_image' => $catimage,
                'ctg_dated' => time()
            );
            $this->b2bcategory_model->form_insert($data);

        }
    }