[PATCH v2 2/2] phy: qcom: qmp-combo: Add PM suspend/resume callbacks

[Prashanth K <prashanth.k@oss.qualcomm.com>]

Currently when we perform system suspend, the phy clocks aren't
turned off leading to power leakage. Prevent this by adding PM
suspend/resume callbacks for the qmp-combo-phy which toggles
clocks on/off correspondingly.

While at it, add mutex guard in runtime_suspend/resume in order
to prevent any race between RT operations and phy_init/exit(),
as it can lead to unclocked register access crash, underflowing
the clock enable counts.

Signed-off-by: Prashanth K <prashanth.k@oss.qualcomm.com>
---
 drivers/phy/qualcomm/phy-qcom-qmp-combo.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-combo.c b/drivers/phy/qualcomm/phy-qcom-qmp-combo.c
index 187f0cd11f6c..65d280f45db1 100644
--- a/drivers/phy/qualcomm/phy-qcom-qmp-combo.c
+++ b/drivers/phy/qualcomm/phy-qcom-qmp-combo.c
@@ -4717,6 +4717,8 @@ static int __maybe_unused qmp_combo_runtime_suspend(struct device *dev)
 
 	dev_vdbg(dev, "Suspending QMP phy, mode:%d\n", qmp->phy_mode);
 
+	guard(mutex)(&qmp->phy_mutex);
+
 	if (!qmp->init_count) {
 		dev_vdbg(dev, "PHY not initialized, bailing out\n");
 		return 0;
@@ -4737,6 +4739,8 @@ static int __maybe_unused qmp_combo_runtime_resume(struct device *dev)
 
 	dev_vdbg(dev, "Resuming QMP phy, mode:%d\n", qmp->phy_mode);
 
+	guard(mutex)(&qmp->phy_mutex);
+
 	if (!qmp->init_count) {
 		dev_vdbg(dev, "PHY not initialized, bailing out\n");
 		return 0;
@@ -4761,6 +4765,7 @@ static int __maybe_unused qmp_combo_runtime_resume(struct device *dev)
 static const struct dev_pm_ops qmp_combo_pm_ops = {
 	SET_RUNTIME_PM_OPS(qmp_combo_runtime_suspend,
 			   qmp_combo_runtime_resume, NULL)
+	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, pm_runtime_force_resume)
 };
 
 static int qmp_combo_reset_init(struct qmp_combo *qmp)
@@ -5749,7 +5754,7 @@ static struct platform_driver qmp_combo_driver = {
 	.probe		= qmp_combo_probe,
 	.driver = {
 		.name	= "qcom-qmp-combo-phy",
-		.pm	= &qmp_combo_pm_ops,
+		.pm	= pm_ptr(&qmp_combo_pm_ops),
 		.of_match_table = qmp_combo_of_match_table,
 	},
 };
-- 
2.34.1