ADP_CS_4
ret = tb_port_read(port, &nfc_credits, TB_CFG_PORT, ADP_CS_4, 1);
TB_CFG_PORT, ADP_CS_4, 1);
ret = tb_port_read(port, &val, TB_CFG_PORT, ADP_CS_4, 1);
return tb_port_write(port, &val, TB_CFG_PORT, ADP_CS_4, 1);