[PATCH v4 14/24] iommu/mediatek: Add pm runtime callback

[Yong Wu]

This patch adds pm runtime callback.

In pm runtime case, all the registers backup/restore and bclk are
controlled in the pm_runtime callback, then pm_suspend is not needed in
this case.

runtime PM is disabled when suspend, thus we call
pm_runtime_status_suspended instead of pm_runtime_suspended.

And, m4u doesn't have its special pm runtime domain in previous SoC, in
this case dev->power.runtime_status is RPM_SUSPENDED defaultly, thus add
a "dev->pm_domain" checking for the SoC that has pm runtime domain.

Signed-off-by: Yong Wu <yong.wu@xxxxxxxxxxxx>
---
 drivers/iommu/mtk_iommu.c | 22 ++++++++++++++++++++--
 1 file changed, 20 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index 4ce7e0883e4d..fe16053eda48 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/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;
@@ -847,7 +847,25 @@ static int __maybe_unused mtk_iommu_resume(struct device *dev)
 	return 0;
 }
 
+static int __maybe_unused mtk_iommu_suspend(struct device *dev)
+{
+	/* runtime PM is disabled when suspend in pm_runtime case. */
+	if (dev->pm_domain && pm_runtime_status_suspended(dev))
+		return 0;
+
+	return mtk_iommu_runtime_suspend(dev);
+}
+
+static int __maybe_unused mtk_iommu_resume(struct device *dev)
+{
+	if (dev->pm_domain && pm_runtime_status_suspended(dev))
+		return 0;
+
+	return mtk_iommu_runtime_resume(dev);
+}
+
 static const struct dev_pm_ops mtk_iommu_pm_ops = {
+	SET_RUNTIME_PM_OPS(mtk_iommu_runtime_suspend, mtk_iommu_runtime_resume, NULL)
 	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(mtk_iommu_suspend, mtk_iommu_resume)
 };
 
-- 
2.18.0