From: Akashdeep Kaur <a-kaur@ti.com>
Date: Fri, 13 Mar 2026 11:17:40 +0000 (+0530)
Subject: rtc: ti-k3: Add support to resume from IO DDR low power mode
X-Git-Tag: v7.1-rc1~5^2~3
X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=0e9b12ee74c57617bb362deb3c82e35fe49694b5;p=thirdparty%2Flinux.git

rtc: ti-k3: Add support to resume from IO DDR low power mode

Restore the RTC HW context which may be lost when system enters
certain low power mode (IO+DDR mode).
Check if the RTC registers are locked which would indicate loss of
context (reset) and restore the context as needed.

Signed-off-by: Akashdeep Kaur <a-kaur@ti.com>
Reviewed-by: Vignesh Raghavendra <vigneshr@ti.com>
Link: https://patch.msgid.link/20260313111740.1492519-1-a-kaur@ti.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
---

diff --git a/drivers/rtc/rtc-ti-k3.c b/drivers/rtc/rtc-ti-k3.c
index ec759d8f7023..e801f5b9d757 100644
--- a/drivers/rtc/rtc-ti-k3.c
+++ b/drivers/rtc/rtc-ti-k3.c
@@ -640,10 +640,18 @@ static int __maybe_unused ti_k3_rtc_suspend(struct device *dev)
 static int __maybe_unused ti_k3_rtc_resume(struct device *dev)
 {
 	struct ti_k3_rtc *priv = dev_get_drvdata(dev);
+	int ret = 0;
+
+	if (k3rtc_check_unlocked(priv)) {
+		/* RTC locked implies low power mode exit where RTC loses context */
+		ret = k3rtc_configure(dev);
+		if (ret)
+			return ret;
+	}
 
 	if (device_may_wakeup(dev))
 		disable_irq_wake(priv->irq);
-	return 0;
+	return ret;
 }
 
 static SIMPLE_DEV_PM_OPS(ti_k3_rtc_pm_ops, ti_k3_rtc_suspend, ti_k3_rtc_resume);