diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index 189165e7a2ab64024f61ba2a95c6f15ccce7fd94..0fe7c1617dc38824acbcb7491bb330388c172788 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -20,6 +20,7 @@
 #include <linux/of_irq.h>
 #include <linux/of_platform.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/regmap.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
@@ -633,6 +634,9 @@ static int mtk_iommu_probe(struct platform_device *pdev)
 {
 	struct mtk_iommu_data   *data;
 	struct device           *dev = &pdev->dev;
+	struct device_node	*larbnode, *smicomm_node;
+	struct platform_device	*plarbdev;
+	struct device_link	*link;
 	struct resource         *res;
 	resource_size_t		ioaddr;
 	struct component_match  *match = NULL;
@@ -699,8 +703,6 @@ static int mtk_iommu_probe(struct platform_device *pdev)
 		return larb_nr;
 
 	for (i = 0; i < larb_nr; i++) {
-		struct device_node *larbnode;
-		struct platform_device *plarbdev;
 		u32 id;
 
 		larbnode = of_parse_phandle(dev->of_node, "mediatek,larbs", i);
@@ -727,12 +729,28 @@ static int mtk_iommu_probe(struct platform_device *pdev)
 					    compare_of, larbnode);
 	}
 
+	/* Get smi-common dev from the last larb. */
+	smicomm_node = of_parse_phandle(larbnode, "mediatek,smi", 0);
+	if (!smicomm_node)
+		return -EINVAL;
+
+	plarbdev = of_find_device_by_node(smicomm_node);
+	of_node_put(smicomm_node);
+	data->smicomm_dev = &plarbdev->dev;
+
+	link = device_link_add(data->smicomm_dev, dev,
+			DL_FLAG_STATELESS | DL_FLAG_PM_RUNTIME);
+	if (!link) {
+		dev_err(dev, "Unable link %s.\n", dev_name(data->smicomm_dev));
+		return -EINVAL;
+	}
+
 	platform_set_drvdata(pdev, data);
 
 	ret = iommu_device_sysfs_add(&data->iommu, dev, NULL,
 				     "mtk-iommu.%pa", &ioaddr);
 	if (ret)
-		return ret;
+		goto out_link_remove;
 
 	iommu_device_set_ops(&data->iommu, &mtk_iommu_ops);
 	iommu_device_set_fwnode(&data->iommu, &pdev->dev.of_node->fwnode);
@@ -762,6 +780,8 @@ static int mtk_iommu_probe(struct platform_device *pdev)
 	iommu_device_unregister(&data->iommu);
 out_sysfs_remove:
 	iommu_device_sysfs_remove(&data->iommu);
+out_link_remove:
+	device_link_remove(data->smicomm_dev, dev);
 	return ret;
 }
 
@@ -776,6 +796,7 @@ static int mtk_iommu_remove(struct platform_device *pdev)
 		bus_set_iommu(&platform_bus_type, NULL);
 
 	clk_disable_unprepare(data->bclk);
+	device_link_remove(data->smicomm_dev, &pdev->dev);
 	devm_free_irq(&pdev->dev, data->irq, data);
 	component_master_del(&pdev->dev, &mtk_iommu_com_ops);
 	return 0;
diff --git a/drivers/iommu/mtk_iommu.h b/drivers/iommu/mtk_iommu.h
index c1584dea66cbed6263ba86cf14565d4f26292045..a9b79e118f02fbe4b687ea614d64c277d3ce2c92 100644
--- a/drivers/iommu/mtk_iommu.h
+++ b/drivers/iommu/mtk_iommu.h
@@ -68,6 +68,7 @@ struct mtk_iommu_data {
 
 	struct iommu_device		iommu;
 	const struct mtk_iommu_plat_data *plat_data;
+	struct device			*smicomm_dev;
 
 	struct dma_iommu_mapping	*mapping; /* For mtk_iommu_v1.c */