From 65f095ea8ff1d62f93a13a2c65fefd985a9951cb Mon Sep 17 00:00:00 2001 From: Prakash Gupta Date: Tue, 16 May 2017 12:13:02 +0530 Subject: [PATCH] iommu/arm-smmu: Add support for regulator deferred disable In case of unmap call, regulator is enabled/disabled. This may introduce additional delay. For clients who do not detach, it's not possible to keep regulator vote while smmu is attached. Add support for regulator deferred disable. The time delay for deferred disable can be set using dt property qcom,deferred-regulator-disable-delay in ms. Change-Id: I462e1999bd81f6332169b24749632d7b247c75c5 Signed-off-by: Prakash Gupta --- Documentation/devicetree/bindings/iommu/arm,smmu.txt | 6 ++++++ drivers/iommu/arm-smmu.c | 10 +++++++++- 2 files changed, 15 insertions(+), 1 deletion(-) diff --git a/Documentation/devicetree/bindings/iommu/arm,smmu.txt b/Documentation/devicetree/bindings/iommu/arm,smmu.txt index 9e512d1ea763..c16084a89ccf 100644 --- a/Documentation/devicetree/bindings/iommu/arm,smmu.txt +++ b/Documentation/devicetree/bindings/iommu/arm,smmu.txt @@ -121,6 +121,12 @@ conditions. supported as we are directly comparing client SID with ID bits of SMR registers. +- qcom,deferred-regulator-disable-delay : The time delay for deferred regulator + disable in ms. In case of unmap call, regulator is + enabled/disabled. This may introduce additional delay. For + clients who do not detach, it's not possible to keep regulator + vote while smmu is attached. Type is . + - clocks : List of clocks to be used during SMMU register access. See Documentation/devicetree/bindings/clock/clock-bindings.txt for information about the format. For each clock specified diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c index 065379c1397f..f14812fdee6c 100644 --- a/drivers/iommu/arm-smmu.c +++ b/drivers/iommu/arm-smmu.c @@ -404,6 +404,7 @@ struct arm_smmu_device { struct msm_bus_scale_pdata *bus_pdata; enum tz_smmu_device_id sec_id; + int regulator_defer; }; struct arm_smmu_cfg { @@ -950,7 +951,8 @@ static int arm_smmu_disable_regulators(struct arm_smmu_device *smmu) arm_smmu_unprepare_clocks(smmu); arm_smmu_unrequest_bus(smmu); if (smmu->gdsc) { - ret = regulator_disable(smmu->gdsc); + ret = regulator_disable_deferred(smmu->gdsc, + smmu->regulator_defer); WARN(ret, "%s: Regulator disable failed\n", dev_name(smmu->dev)); } @@ -3610,6 +3612,12 @@ static int arm_smmu_init_regulators(struct arm_smmu_device *smmu) if (!of_get_property(dev->of_node, "vdd-supply", NULL)) return 0; + if (!of_property_read_u32(dev->of_node, + "qcom,deferred-regulator-disable-delay", + &(smmu->regulator_defer))) + dev_info(dev, "regulator defer delay %d\n", + smmu->regulator_defer); + smmu->gdsc = devm_regulator_get(dev, "vdd"); if (IS_ERR(smmu->gdsc)) return PTR_ERR(smmu->gdsc);