iommu/arm-smmu: Reorganize code to allow no gdsc

Some SMMUs may not have a dedicated gdsc for it.
Allow for the enable code to prepare clocks and vote
for bus requests even if there is no gdsc provided.

Change-Id: Iaedfb73d8ae7f12895472893468e5c32d2bf2462
Signed-off-by: Rohit Vaswani <rvaswani@codeaurora.org>

1 files changed, 18 insertions, 17 deletions

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index f4fc6f951648..9d8c7dc4de7a 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -751,11 +751,10 @@ static int arm_smmu_unrequest_bus(struct arm_smmu_device *smmu)
 
 static int arm_smmu_disable_regulators(struct arm_smmu_device *smmu)
 {
-	if (!smmu->gdsc)
-		return 0;
-
 	arm_smmu_unprepare_clocks(smmu);
 	arm_smmu_unrequest_bus(smmu);
+	if (!smmu->gdsc)
+		return 0;
 	return regulator_disable(smmu->gdsc);
 }
 
@@ -763,25 +762,27 @@ static int arm_smmu_enable_regulators(struct arm_smmu_device *smmu)
 {
 	int ret;
 
-	if (!smmu->gdsc)
-		return 0;
-
-	ret = regulator_enable(smmu->gdsc);
-	if (ret)
-		return ret;
+	if (smmu->gdsc) {
+		ret = regulator_enable(smmu->gdsc);
+		if (ret)
+			goto out;
+	}
 
 	ret = arm_smmu_request_bus(smmu);
-	if (ret) {
-		regulator_disable(smmu->gdsc);
-		goto out;
-	}
+	if (ret)
+		goto out_reg;
 
 	ret = arm_smmu_prepare_clocks(smmu);
-	if (ret) {
-		arm_smmu_unrequest_bus(smmu);
-		regulator_disable(smmu->gdsc);
-	}
+	if (ret)
+		goto out_bus;
+
+	return ret;
 
+out_bus:
+	arm_smmu_unrequest_bus(smmu);
+out_reg:
+	if (smmu->gdsc)
+		regulator_disable(smmu->gdsc);
 out:
 	return ret;
 }