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>
---

Tested deep sleep with rtcwake after IO DDR resume on AM62P-SK.

Changes in v2:
  -Updated the commit message as suggested in review
  -Link to v1: https://lore.kernel.org/all/20260311070214.3589965-1-a-kaur@ti.com/

---
 drivers/rtc/rtc-ti-k3.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

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);
-- 
2.34.1

On 3/13/2026 4:47 PM, Akashdeep Kaur wrote:
> 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>

> ---
> 
> Tested deep sleep with rtcwake after IO DDR resume on AM62P-SK.
> 
> Changes in v2:
>   -Updated the commit message as suggested in review
>   -Link to v1: https://lore.kernel.org/all/20260311070214.3589965-1-a-kaur@ti.com/
> 
> ---
>  drivers/rtc/rtc-ti-k3.c | 10 +++++++++-
>  1 file changed, 9 insertions(+), 1 deletion(-)
> 
> 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);