[PATCH 2/3] iommu/arm-smmu: Add optional SMMU clock
From: thor.thayer at linux.intel.com <hidden>
Date: 2018-07-13 16:27:57
Also in:
linux-devicetree, linux-iommu
Subsystem:
iommu subsystem, the rest · Maintainers:
Joerg Roedel, Will Deacon, Linus Torvalds
From: Thor Thayer <redacted> Add a clock to the SMMU structure. In the device tree case, check for a clock handle and enable the clock if found. Signed-off-by: Thor Thayer <redacted> --- drivers/iommu/arm-smmu.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+)
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 69e7c60792a8..0e6dd5019c23 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c@@ -212,6 +212,7 @@ struct arm_smmu_device { /* IOMMU core code handle */ struct iommu_device iommu; + struct clk *clk; }; enum arm_smmu_context_fmt {
@@ -1992,6 +1993,15 @@ static int arm_smmu_device_dt_probe(struct platform_device *pdev, struct device *dev = &pdev->dev; bool legacy_binding; + /* If a clock is declared, enable it */ + smmu->clk = devm_clk_get(smmu->dev, NULL); + if (IS_ERR(smmu->clk)) { + smmu->clk = NULL; + dev_dbg(dev, "cannot get smmu clock\n"); + } else { + clk_prepare_enable(smmu->clk); + } + if (of_property_read_u32(dev->of_node, "#global-interrupts", &smmu->num_global_irqs)) { dev_err(dev, "missing #global-interrupts property\n");
@@ -2181,6 +2191,10 @@ static int arm_smmu_device_remove(struct platform_device *pdev) /* Turn the thing off */ writel(sCR0_CLIENTPD, ARM_SMMU_GR0_NS(smmu) + ARM_SMMU_GR0_sCR0); + + if (smmu->clk) + clk_disable_unprepare(smmu->clk); + return 0; }
@@ -2193,6 +2207,9 @@ static int __maybe_unused arm_smmu_pm_resume(struct device *dev) { struct arm_smmu_device *smmu = dev_get_drvdata(dev); + if (smmu->clk) + clk_prepare_enable(smmu->clk); + arm_smmu_device_reset(smmu); return 0; }
--
2.7.4