Hi KyongHo,
On Thursday 08 of August 2013 18:39:05 Cho KyongHo wrote:
> 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);
This should be done in a more appropriate way, but at the moment the PM
Core doesn't have any provision to implement any sane solution for this
kind of problems, so this is fine.
Reviewed-by: Tomasz Figa <t.f...@samsung.com>
Best regards,
Tomasz
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