[PATCH v6 07/22] 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.

Currently mt2712 and mt8173 have this bclk while mt8183 doesn't.

This also is a preparing patch for mt8183.

Signed-off-by: Yong Wu <yong.wu@mediatek.com>
Reviewed-by: Evan Green <evgreen@chromium.org>
---
 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 b2d517c..685f5d5 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -611,9 +611,11 @@ 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);
@@ -737,11 +739,13 @@ 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