[PATCH v9 10/12] iommu/arm-smmu-v3: Enable pm_runtime and setup devlinks

[Pranjal Shrivastava <praan@google.com>]

Enable PM runtime for SMMUs having a power-domain during smmu probe.
Add a devlink between the clients and SMMU device. The absence of a
power domain effectively disables runtime power management.

Reviewed-by: Mostafa Saleh <smostafa@google.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Pranjal Shrivastava <praan@google.com>
---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index 5f0e01dc4f6a..1253065b6db4 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -4431,6 +4431,9 @@ static struct iommu_device *arm_smmu_probe_device(struct device *dev)
 	if (ret)
 		goto err_disable_pasid;
 
+	device_link_add(dev, smmu->dev,
+			DL_FLAG_PM_RUNTIME | DL_FLAG_AUTOREMOVE_SUPPLIER);
+
 	return &smmu->iommu;
 
 err_disable_pasid:
@@ -5821,6 +5824,13 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
 		return ret;
 	}
 
+	if (dev->pm_domain) {
+		pm_runtime_set_active(dev);
+		pm_runtime_use_autosuspend(dev);
+		pm_runtime_set_autosuspend_delay(dev, RPM_AUTOSUSPEND_DELAY_MS);
+		pm_runtime_enable(dev);
+	}
+
 	return 0;
 }
 
-- 
2.55.0.487.gaf234c4eb3-goog