This driver will get support for more SoCs and the list of infracfg compatibles is expected to grow: in order to prevent getting this situation out of control and see a long list of compatible strings, add support to retrieve a handle to infracfg's regmap through a new "mediatek,infracfg" phandle. In order to keep retrocompatibility with older devicetrees, the old way is kept in place, but also a dev_warn() was added to advertise this change in hope that the user will see it and eventually update the devicetree if this is possible. Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx> --- drivers/iommu/mtk_iommu.c | 40 +++++++++++++++++++++++++-------------- 1 file changed, 26 insertions(+), 14 deletions(-) diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c index 71b2ace74cd6..cfaaa98d2b50 100644 --- a/drivers/iommu/mtk_iommu.c +++ b/drivers/iommu/mtk_iommu.c @@ -1134,22 +1134,34 @@ static int mtk_iommu_probe(struct platform_device *pdev) data->protect_base = ALIGN(virt_to_phys(protect), MTK_PROTECT_PA_ALIGN); if (MTK_IOMMU_HAS_FLAG(data->plat_data, HAS_4GB_MODE)) { - switch (data->plat_data->m4u_plat) { - case M4U_MT2712: - p = "mediatek,mt2712-infracfg"; - break; - case M4U_MT8173: - p = "mediatek,mt8173-infracfg"; - break; - default: - p = NULL; + infracfg = syscon_regmap_lookup_by_phandle(dev->of_node, "mediatek,infracfg"); + if (IS_ERR(infracfg)) { + dev_warn(dev, "Cannot find phandle to mediatek,infracfg:" + " Please update your devicetree.\n"); + /* + * Legacy devicetrees will not specify a phandle to + * mediatek,infracfg: in that case, we use the older + * way to retrieve a syscon to infra. + * + * This is for retrocompatibility purposes only, hence + * no more compatibles shall be added to this. + */ + switch (data->plat_data->m4u_plat) { + case M4U_MT2712: + p = "mediatek,mt2712-infracfg"; + break; + case M4U_MT8173: + p = "mediatek,mt8173-infracfg"; + break; + default: + p = NULL; + } + + infracfg = syscon_regmap_lookup_by_compatible(p); + if (IS_ERR(infracfg)) + return PTR_ERR(infracfg); } - infracfg = syscon_regmap_lookup_by_compatible(p); - - if (IS_ERR(infracfg)) - return PTR_ERR(infracfg); - ret = regmap_read(infracfg, REG_INFRA_MISC, &val); if (ret) return ret; -- 2.35.1