[PATCH v4 18/35] iommu/mediatek: Adjust device link when it is sub-common

[Yong Wu]

For MM IOMMU, We always add device link between smi-common and IOMMU HW.
In mt8195, we add smi-sub-common. Thus, if the node is sub-common, we still
need find again to get smi-common, then do device link.

Signed-off-by: Yong Wu <yong.wu at mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno at collabora.com>
---
 drivers/iommu/mtk_iommu.c | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index 71f3acd00d8c..f676085af13d 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -798,9 +798,9 @@ static int mtk_iommu_mm_dts_parse(struct device *dev,
 				  struct component_match **match,
 				  struct mtk_iommu_data *data)
 {
+	struct device_node *larbnode, *smicomm_node, *smi_subcomm_node;
 	struct platform_device	*plarbdev;
 	struct device_link	*link;
-	struct device_node *larbnode, *smicomm_node;
 	int i, larb_nr, ret;
 
 	larb_nr = of_count_phandle_with_args(dev->of_node, "mediatek,larbs", NULL);
@@ -834,11 +834,21 @@ static int mtk_iommu_mm_dts_parse(struct device *dev,
 					    compare_of, larbnode);
 	}
 
-	/* Get smi-common dev from the last larb. */
-	smicomm_node = of_parse_phandle(larbnode, "mediatek,smi", 0);
-	if (!smicomm_node)
+	/* Get smi-(sub)-common dev from the last larb. */
+	smi_subcomm_node = of_parse_phandle(larbnode, "mediatek,smi", 0);
+	if (!smi_subcomm_node)
 		return -EINVAL;
 
+	/*
+	 * It may have two level smi-common. the node is smi-sub-common if it
+	 * has a new mediatek,smi property. otherwise it is smi-commmon.
+	 */
+	smicomm_node = of_parse_phandle(smi_subcomm_node, "mediatek,smi", 0);
+	if (smicomm_node)
+		of_node_put(smi_subcomm_node);
+	else
+		smicomm_node = smi_subcomm_node;
+
 	plarbdev = of_find_device_by_node(smicomm_node);
 	of_node_put(smicomm_node);
 	data->smicomm_dev = &plarbdev->dev;
-- 
2.18.0