iommu/mediatek: Add pm runtime callback

In pm runtime case, all the registers backup/restore and bclk are
controlled in the pm_runtime callback, Rename the original
suspend/resume to the runtime_suspend/resume.

Use pm_runtime_force_suspend/resume as the normal suspend/resume.
iommu should suspend after iommu consumer devices, thus use _LATE_.

Signed-off-by: Yong Wu <yong.wu@mediatek.com>
Reviewed-by: Tomasz Figa <tfiga@chromium.org>
Link: https://lore.kernel.org/r/20210111111914.22211-20-yong.wu@mediatek.com
Signed-off-by: Will Deacon <will@kernel.org>

drivers/iommu/mtk_iommu.c

@@ -802,7 +802,7 @@ static int mtk_iommu_remove(struct platform_device *pdev)
 	return 0;
 }
 
-static int __maybe_unused mtk_iommu_suspend(struct device *dev)
+static int __maybe_unused mtk_iommu_runtime_suspend(struct device *dev)
 {
 	struct mtk_iommu_data *data = dev_get_drvdata(dev);
 	struct mtk_iommu_suspend_reg *reg = &data->reg;
@@ -820,7 +820,7 @@ static int __maybe_unused mtk_iommu_suspend(struct device *dev)
 	return 0;
 }
 
-static int __maybe_unused mtk_iommu_resume(struct device *dev)
+static int __maybe_unused mtk_iommu_runtime_resume(struct device *dev)
 {
 	struct mtk_iommu_data *data = dev_get_drvdata(dev);
 	struct mtk_iommu_suspend_reg *reg = &data->reg;
@@ -848,7 +848,9 @@ static int __maybe_unused mtk_iommu_resume(struct device *dev)
 }
 
 static const struct dev_pm_ops mtk_iommu_pm_ops = {
-	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(mtk_iommu_suspend, mtk_iommu_resume)
+	SET_RUNTIME_PM_OPS(mtk_iommu_runtime_suspend, mtk_iommu_runtime_resume, NULL)
+	SET_LATE_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+				     pm_runtime_force_resume)
 };
 
 static const struct mtk_iommu_plat_data mt2712_data = {