tb_cfg_read
int tb_cfg_read(struct tb_ctl *ctl, void *buffer, u64 route, u32 port,
ret = tb_cfg_read(tb->ctl, &sw->config, route, 0, TB_CFG_SWITCH, 0, 5);
return tb_cfg_read(sw->tb->ctl,
return tb_cfg_read(port->sw->tb->ctl,