On Mon, Aug 30, 2021 at 03:09:44PM +0800, Chuanjia Liu wrote: > On Fri, 2021-08-27 at 11:46 -0500, Bjorn Helgaas wrote: > > On Mon, Aug 23, 2021 at 11:27:56AM +0800, Chuanjia Liu wrote: > > > @@ -995,6 +1004,14 @@ static int mtk_pcie_subsys_powerup(struct > > > mtk_pcie *pcie) > > > return PTR_ERR(pcie->base); > > > } > > > > > > + cfg_node = of_find_compatible_node(NULL, NULL, > > > + "mediatek,generic-pciecfg"); > > > + if (cfg_node) { > > > + pcie->cfg = syscon_node_to_regmap(cfg_node); > > > > Other drivers in drivers/pci/controller/ use > > syscon_regmap_lookup_by_phandle() (j721e, dra7xx, keystone, > > layerscape, artpec6) or syscon_regmap_lookup_by_compatible() (imx6, > > kirin, v3-semi). > > > > You should do it the same way unless there's a need to be different. > > I have used phandle, but Rob suggested to search for the node by > compatible. > The reason why syscon_regmap_lookup_by_compatible() is not > used here is that the pciecfg node is optional, and there is no need to > return error when the node is not searched. How about this? regmap = syscon_regmap_lookup_by_compatible("mediatek,generic-pciecfg"); if (!IS_ERR(regmap)) pcie->cfg = regmap;