[PATCH v4 07/18] iommu/mediatek: Add bclk can be supported optionally

[Yong Wu <yong.wu@mediatek.com>]

In some SoCs, M4U doesn't have its "bclk", it will use the EMI
clock instead which has always been enabled when entering kernel.

This also is a preparing patch for mt8183.

Signed-off-by: Yong Wu <yong.wu@mediatek.com>
---
 drivers/iommu/mtk_iommu.c | 10 +++++++---
 drivers/iommu/mtk_iommu.h |  3 +++
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index 8eb110e..eda062a 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -610,9 +610,11 @@ static int mtk_iommu_probe(struct platform_device *pdev)
 	if (data->irq < 0)
 		return data->irq;
 
-	data->bclk = devm_clk_get(dev, "bclk");
-	if (IS_ERR(data->bclk))
-		return PTR_ERR(data->bclk);
+	if (data->plat_data->has_bclk) {
+		data->bclk = devm_clk_get(dev, "bclk");
+		if (IS_ERR(data->bclk))
+			return PTR_ERR(data->bclk);
+	}
 
 	larb_nr = of_count_phandle_with_args(dev->of_node,
 					     "mediatek,larbs", NULL);
@@ -736,11 +738,13 @@ static int __maybe_unused mtk_iommu_resume(struct device *dev)
 static const struct mtk_iommu_plat_data mt2712_data = {
 	.m4u_plat     = M4U_MT2712,
 	.has_4gb_mode = true,
+	.has_bclk     = true,
 };
 
 static const struct mtk_iommu_plat_data mt8173_data = {
 	.m4u_plat     = M4U_MT8173,
 	.has_4gb_mode = true,
+	.has_bclk     = true,
 };
 
 static const struct of_device_id mtk_iommu_of_ids[] = {
diff --git a/drivers/iommu/mtk_iommu.h b/drivers/iommu/mtk_iommu.h
index 5890e55..b8749ac 100644
--- a/drivers/iommu/mtk_iommu.h
+++ b/drivers/iommu/mtk_iommu.h
@@ -44,6 +44,9 @@ enum mtk_iommu_plat {
 struct mtk_iommu_plat_data {
 	enum mtk_iommu_plat m4u_plat;
 	bool                has_4gb_mode;
+
+	/* HW will use the EMI clock if there isn't the "bclk". */
+	bool                has_bclk;
 };
 
 struct mtk_iommu_domain;
-- 
1.9.1