[PATCH v2 3/7] iommu: mtk_iommu: Lookup phandle to retrieve syscon to pericfg

AngeloGioacchino Del Regno
2022-05-18T10:05:32Z

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Also following the previous infracfg change, add a warning for outdated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.delregno@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