This patch gates clocks of master H/W as well as clocks of System MMU if master clocks are specified. Some Exynos SoCs (i.e. GScalers in Exynos5250) have dependencies in the gating clocks of master H/W and its System MMU. If a H/W is the case, accessing control registers of System MMU is prohibited unless both of the gating clocks of System MMU and its master H/W. Signed-off-by: Cho KyongHo <pullip.cho@xxxxxxxxxxx> --- drivers/iommu/exynos-iommu.c | 38 ++++++++++++++++++++++++++++++++++---- 1 files changed, 34 insertions(+), 4 deletions(-) diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c index 0ee73e8..005a7ed 100644 --- a/drivers/iommu/exynos-iommu.c +++ b/drivers/iommu/exynos-iommu.c @@ -173,6 +173,7 @@ struct sysmmu_drvdata { struct device *dev; /* Owner of system MMU */ int nsfrs; struct clk *clk; + struct clk *clk_master; int activations; rwlock_t lock; struct iommu_domain *domain; @@ -263,6 +264,8 @@ void exynos_sysmmu_set_prefbuf(struct device *dev, if (!is_sysmmu_active(data)) goto finish; + clk_enable(data->clk_master); + for (i = 0; i < data->nsfrs; i++) { if ((readl(data->sfrbases[i] + REG_MMU_VERSION) >> 28) == 3) { if (!sysmmu_block(data->sfrbases[i])) @@ -288,6 +291,8 @@ void exynos_sysmmu_set_prefbuf(struct device *dev, sysmmu_unblock(data->sfrbases[i]); } } + + clk_disable(data->clk_master); finish: read_unlock_irqrestore(&data->lock, flags); } @@ -358,6 +363,8 @@ static irqreturn_t exynos_sysmmu_irq(int irq, void *dev_id) break; } + clk_enable(data->clk_master); + if (i == pdev->num_resources) { itype = SYSMMU_FAULT_UNKNOWN; } else { @@ -391,6 +398,8 @@ static irqreturn_t exynos_sysmmu_irq(int irq, void *dev_id) if (itype != SYSMMU_FAULT_UNKNOWN) sysmmu_unblock(data->sfrbases[i]); + clk_disable(data->clk_master); + read_unlock(&data->lock); return IRQ_HANDLED; @@ -407,11 +416,14 @@ static bool __exynos_sysmmu_disable(struct sysmmu_drvdata *data) if (!set_sysmmu_inactive(data)) goto finish; + clk_enable(data->clk_master); + for (i = 0; i < data->nsfrs; i++) __raw_writel(CTRL_DISABLE, data->sfrbases[i] + REG_MMU_CTRL); - if (data->clk) - clk_disable(data->clk); + clk_disable(data->clk_master); + + clk_disable(data->clk); disabled = true; data->pgtable = 0; @@ -454,11 +466,12 @@ static int __exynos_sysmmu_enable(struct sysmmu_drvdata *data, goto finish; } - if (data->clk) - clk_enable(data->clk); + clk_enable(data->clk); data->pgtable = pgtable; + clk_enable(data->clk_master); + for (i = 0; i < data->nsfrs; i++) { __sysmmu_set_ptbase(data->sfrbases[i], pgtable); @@ -473,6 +486,8 @@ static int __exynos_sysmmu_enable(struct sysmmu_drvdata *data, __raw_writel(CTRL_ENABLE, data->sfrbases[i] + REG_MMU_CTRL); } + clk_disable(data->clk_master); + data->domain = domain; dev_dbg(data->sysmmu, "Enabled\n"); @@ -528,6 +543,7 @@ static void sysmmu_tlb_invalidate_entry(struct device *dev, unsigned long iova) if (is_sysmmu_active(data)) { int i; + clk_enable(data->clk_master); for (i = 0; i < data->nsfrs; i++) { if (sysmmu_block(data->sfrbases[i])) { __sysmmu_tlb_invalidate_entry( @@ -535,6 +551,7 @@ static void sysmmu_tlb_invalidate_entry(struct device *dev, unsigned long iova) sysmmu_unblock(data->sfrbases[i]); } } + clk_disable(data->clk_master); } else { dev_dbg(data->sysmmu, "Disabled. Skipping invalidating TLB.\n"); } @@ -551,12 +568,14 @@ void exynos_sysmmu_tlb_invalidate(struct device *dev) if (is_sysmmu_active(data)) { int i; + clk_enable(data->clk_master); for (i = 0; i < data->nsfrs; i++) { if (sysmmu_block(data->sfrbases[i])) { __sysmmu_tlb_invalidate(data->sfrbases[i]); sysmmu_unblock(data->sfrbases[i]); } } + clk_disable(data->clk_master); } else { dev_dbg(data->sysmmu, "Disabled. Skipping invalidating TLB.\n"); } @@ -637,6 +656,17 @@ static int __init exynos_sysmmu_probe(struct platform_device *pdev) return ret; } + data->clk_master = devm_clk_get(dev, "master"); + if (IS_ERR(data->clk_master)) + data->clk_master = NULL; + + ret = clk_prepare(data->clk_master); + if (ret) { + clk_unprepare(data->clk); + dev_err(dev, "Failed to prepare master's clk\n"); + return ret; + } + rwlock_init(&data->lock); INIT_LIST_HEAD(&data->node); -- 1.7.2.5 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html