From: Sricharan R <redacted>

Finally add the device link between the master device and
smmu, so that the smmu gets runtime enabled/disabled only when the
master needs it. This is done from add_device callback which gets
called once when the master is added to the smmu.

Signed-off-by: Sricharan R <redacted>
Signed-off-by: Vivek Gautam <redacted>
---
 drivers/iommu/arm-smmu.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index c024f69c1682..c7e924d553bd 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c

@@ -215,6 +215,9 @@ struct arm_smmu_device {

        /* IOMMU core code handle */
        struct iommu_device             iommu;
+
+       /* runtime PM link to master */
+       struct device_link *link;
 };

 enum arm_smmu_context_fmt {

@@ -1425,6 +1428,17 @@ static int arm_smmu_add_device(struct device *dev)

        pm_runtime_put_sync(smmu->dev);

+       /*
+        * Establish the link between smmu and master, so that the
+        * smmu gets runtime enabled/disabled as per the master's
+        * needs.
+        */
+       smmu->link = device_link_add(dev, smmu->dev, DL_FLAG_PM_RUNTIME);
+       if (!smmu->link)
+               dev_warn(smmu->dev,
+                        "Unable to create device link between %s and %s\n",
+                        dev_name(smmu->dev), dev_name(dev));

+
        return 0;

 out_rpm_put:

@@ -1449,6 +1463,8 @@ static void arm_smmu_remove_device(struct device *dev)
        cfg  = fwspec->iommu_priv;
        smmu = cfg->smmu;

+       device_link_del(smmu->link);