Problem ketika memanggil model

gan saya ada function controller buat memanggil model tapi pesannya Message: Call to a member function carii() on null , kira-kira salahnya yg dimana ya

ini controllernya

	public function cari()
		{
		$data['pilihan'] = $this->input->post("pilihan");
		$data['ygdicari'] = $this->input->post("ygdicari");
		$data['query_no'] = $this->model_perusahaan->carii($data['pilihan'],$data['ygdicari']);
		$data['jumlah'] = count($data["query_no"]);
		$this->load->view("tampilan_user",$data);
		}

ini model

<?php

	Class Model_perusahaan extends CI_Model
	{
		public function getdata($key)
		{
			$this->db->where('idperusahaan',$key);
			$hasil =$this->db->get('perusahaan');
			return $hasil;
		}

		public function getupdate($key,$data)
		{
			$this->db->where('idperusahaan',$key);
			$this->db->update('perusahaan',$data);
		}

		public function getinsert($data)
		{
			$this->db->insert('perusahaan',$data);
		}

		public function getdelete($key)
		{
			$this->db->where('idperusahaan',$key);
			$this->db->delete('perusahaan');
		}

		public function carii($pilihan,$ygdicari)
		{
			$this->db->from("perusahaan");
			$this->db->like($pilihan,$ygdicari);
			return $this->db->get();
		}
	}

?>