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....@samsung.com>
---
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 linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
