On some SoCs (of which only MT8195 is supported at the time of writing),
the "R" and "W" (I/O) enable bits for the IOMMUs are in the pericfg_ao
register space and not in the IOMMU space: as it happened already with
infracfg, it is expected that this list will grow.

Instead of specifying pericfg compatibles on a per-SoC basis, following
what was done with infracfg, let's lookup the syscon by phandle instead.
Also following the previous infracfg change, add a warning for outdated
devicetrees, in hope that the user will take action.

Signed-off-by: AngeloGioacchino Del Regno 
<angelogioacchino.delre...@collabora.com>
---
 drivers/iommu/mtk_iommu.c | 26 ++++++++++++++++----------
 1 file changed, 16 insertions(+), 10 deletions(-)

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index d16b95e71ded..090cf6e15f85 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -138,6 +138,8 @@
 /* PM and clock always on. e.g. infra iommu */
 #define PM_CLK_AO                      BIT(15)
 #define IFA_IOMMU_PCIE_SUPPORT         BIT(16)
+/* IOMMU I/O (r/w) is enabled using PERICFG_IOMMU_1 register */
+#define HAS_PERI_IOMMU1_REG            BIT(17)
 
 #define MTK_IOMMU_HAS_FLAG_MASK(pdata, _x, mask)       \
                                ((((pdata)->flags) & (mask)) == (_x))
@@ -187,7 +189,6 @@ struct mtk_iommu_plat_data {
        u32                     flags;
        u32                     inv_sel_reg;
 
-       char                    *pericfg_comp_str;
        struct list_head        *hw_list;
        unsigned int            iova_region_nr;
        const struct mtk_iommu_iova_region      *iova_region;
@@ -1214,14 +1215,19 @@ static int mtk_iommu_probe(struct platform_device *pdev)
                        goto out_runtime_disable;
                }
        } else if (MTK_IOMMU_IS_TYPE(data->plat_data, MTK_IOMMU_TYPE_INFRA) &&
-                  data->plat_data->pericfg_comp_str) {
-               infracfg = 
syscon_regmap_lookup_by_compatible(data->plat_data->pericfg_comp_str);
-               if (IS_ERR(infracfg)) {
-                       ret = PTR_ERR(infracfg);
-                       goto out_runtime_disable;
-               }
+                  MTK_IOMMU_HAS_FLAG(data->plat_data, HAS_PERI_IOMMU1_REG)) {
+               data->pericfg = syscon_regmap_lookup_by_phandle(dev->of_node, 
"mediatek,pericfg");
+               if (IS_ERR(data->pericfg)) {
+                       dev_info(dev, "Cannot find phandle to mediatek,pericfg:"
+                                     " Please update your devicetree.\n");
 
-               data->pericfg = infracfg;
+                       p = "mediatek,mt8195-pericfg_ao";
+                       data->pericfg = syscon_regmap_lookup_by_compatible(p);
+                       if (IS_ERR(data->pericfg)) {
+                               ret = PTR_ERR(data->pericfg);
+                               goto out_runtime_disable;
+                       }
+               }
        }
 
        platform_set_drvdata(pdev, data);
@@ -1480,8 +1486,8 @@ static const struct mtk_iommu_plat_data mt8192_data = {
 static const struct mtk_iommu_plat_data mt8195_data_infra = {
        .m4u_plat         = M4U_MT8195,
        .flags            = WR_THROT_EN | DCM_DISABLE | STD_AXI_MODE | 
PM_CLK_AO |
-                           MTK_IOMMU_TYPE_INFRA | IFA_IOMMU_PCIE_SUPPORT,
-       .pericfg_comp_str = "mediatek,mt8195-pericfg_ao",
+                           HAS_PERI_IOMMU1_REG | MTK_IOMMU_TYPE_INFRA |
+                           IFA_IOMMU_PCIE_SUPPORT,
        .inv_sel_reg      = REG_MMU_INV_SEL_GEN2,
        .banks_num        = 5,
        .banks_enable     = {true, false, false, false, true},
-- 
2.35.1

_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

Reply via email to