[PATCH v3 05/10] ufs: host: mediatek: Support UFS PHY runtime PM and correct sequence

[peter.wang at mediatek.com]

From: Peter Wang <peter.wang at mediatek.com>

Add support for UFS PHY runtime power management by probing the
PHY device and enabling its runtime PM. Ensure the correct sequence
of operations during suspend and resume:
PHY suspend -> UFS suspend -> UFS resume -> PHY resume.
Improve power management efficiency and system stability with this
enhancement.

Signed-off-by: Peter Wang <peter.wang at mediatek.com>
---
 drivers/ufs/host/ufs-mediatek.c | 53 +++++++++++++++++++++++++++++----
 drivers/ufs/host/ufs-mediatek.h |  1 +
 2 files changed, 48 insertions(+), 6 deletions(-)

diff --git a/drivers/ufs/host/ufs-mediatek.c b/drivers/ufs/host/ufs-mediatek.c
index a47713a047c1..5d2de4fc370b 100644
--- a/drivers/ufs/host/ufs-mediatek.c
+++ b/drivers/ufs/host/ufs-mediatek.c
@@ -2243,10 +2243,12 @@ static const struct ufs_hba_variant_ops ufs_hba_mtk_vops = {
 static int ufs_mtk_probe(struct platform_device *pdev)
 {
 	int err;
-	struct device *dev = &pdev->dev;
-	struct device_node *reset_node;
-	struct platform_device *reset_pdev;
+	struct device *dev = &pdev->dev, *phy_dev = NULL;
+	struct device_node *reset_node, *phy_node = NULL;
+	struct platform_device *reset_pdev, *phy_pdev = NULL;
 	struct device_link *link;
+	struct ufs_hba *hba;
+	struct ufs_mtk_host *host;
 
 	reset_node = of_find_compatible_node(NULL, NULL,
 					     "ti,syscon-reset");
@@ -2273,13 +2275,44 @@ static int ufs_mtk_probe(struct platform_device *pdev)
 	}
 
 skip_reset:
+	/* find phy node */
+	phy_node = of_parse_phandle(dev->of_node, "phys", 0);
+
+	if (phy_node) {
+		phy_pdev = of_find_device_by_node(phy_node);
+		if (!phy_pdev)
+			goto skip_phy;
+		phy_dev = &phy_pdev->dev;
+
+		pm_runtime_set_active(phy_dev);
+		pm_runtime_enable(phy_dev);
+		pm_runtime_get_sync(phy_dev);
+
+		put_device(phy_dev);
+		dev_info(dev, "phys node found\n");
+	} else {
+		dev_notice(dev, "phys node not found\n");
+	}
+
+skip_phy:
 	/* perform generic probe */
 	err = ufshcd_pltfrm_init(pdev, &ufs_hba_mtk_vops);
-
-out:
-	if (err)
+	if (err) {
 		dev_err(dev, "probe failed %d\n", err);
+		goto out;
+	}
+
+	hba = platform_get_drvdata(pdev);
+	if (!hba)
+		goto out;
+
+	if (phy_node && phy_dev) {
+		host = ufshcd_get_variant(hba);
+		host->phy_dev = phy_dev;
+	}
 
+out:
+	of_node_put(phy_node);
 	of_node_put(reset_node);
 	return err;
 }
@@ -2343,6 +2376,7 @@ static int ufs_mtk_system_resume(struct device *dev)
 static int ufs_mtk_runtime_suspend(struct device *dev)
 {
 	struct ufs_hba *hba = dev_get_drvdata(dev);
+	struct ufs_mtk_host *host = ufshcd_get_variant(hba);
 	struct arm_smccc_res res;
 	int ret = 0;
 
@@ -2355,17 +2389,24 @@ static int ufs_mtk_runtime_suspend(struct device *dev)
 	if (ufs_mtk_is_rtff_mtcmos(hba))
 		ufs_mtk_mtcmos_ctrl(false, res);
 
+	if (host->phy_dev)
+		pm_runtime_put_sync(host->phy_dev);
+
 	return 0;
 }
 
 static int ufs_mtk_runtime_resume(struct device *dev)
 {
 	struct ufs_hba *hba = dev_get_drvdata(dev);
+	struct ufs_mtk_host *host = ufshcd_get_variant(hba);
 	struct arm_smccc_res res;
 
 	if (ufs_mtk_is_rtff_mtcmos(hba))
 		ufs_mtk_mtcmos_ctrl(true, res);
 
+	if (host->phy_dev)
+		pm_runtime_get_sync(host->phy_dev);
+
 	ufs_mtk_dev_vreg_set_lpm(hba, false);
 
 	return ufshcd_runtime_resume(dev);
diff --git a/drivers/ufs/host/ufs-mediatek.h b/drivers/ufs/host/ufs-mediatek.h
index e46dc5fa209d..dfbf78bd8664 100644
--- a/drivers/ufs/host/ufs-mediatek.h
+++ b/drivers/ufs/host/ufs-mediatek.h
@@ -193,6 +193,7 @@ struct ufs_mtk_host {
 	bool is_mcq_intr_enabled;
 	int mcq_nr_intr;
 	struct ufs_mtk_mcq_intr_info mcq_intr_info[UFSHCD_MAX_Q_NR];
+	struct device *phy_dev;
 };
 
 /* MTK delay of autosuspend: 500 ms */
-- 
2.45.2