rtc: Enhance RTC driver with BBPU bit definitions and shutdown handling

[PATCH v1 2/2] rtc: mt6397: Add BBPU alarm status reset and shutdown handling

Posted by ot_shunxi.zhang@mediatek.com 1 month, 3 weeks ago

From: Shunxi Zhang <ot_shunxi.zhang@mediatek.com>

This patch introduces a new function, mtk_rtc_reset_bbpu_alarm_status,
to reset the BBPU alarm status in the MT6397 RTC driver. This function
writes the necessary bits to the RTC_BBPU register to clear the alarm
status and ensure proper operation.

Additionally, the mtk_rtc_shutdown function is added to handle RTC
shutdown events. It resets the BBPU alarm status and updates the
RTC_IRQ_EN register to disable the one-shot alarm interrupt,
ensuring a clean shutdown process.

Signed-off-by: Shunxi Zhang <ot_shunxi.zhang@mediatek.com>
---
 drivers/rtc/rtc-mt6397.c | 36 +++++++++++++++++++++++++++++++++++-
 1 file changed, 35 insertions(+), 1 deletion(-)

diff --git a/drivers/rtc/rtc-mt6397.c b/drivers/rtc/rtc-mt6397.c
index 692c00ff544b..063bd399de8c 100644
--- a/drivers/rtc/rtc-mt6397.c
+++ b/drivers/rtc/rtc-mt6397.c
@@ -37,6 +37,21 @@ static int mtk_rtc_write_trigger(struct mt6397_rtc *rtc)
 	return ret;
 }
 
+static void mtk_rtc_reset_bbpu_alarm_status(struct mt6397_rtc *rtc)
+{
+	u32 bbpu = RTC_BBPU_KEY | RTC_BBPU_PWREN | RTC_BBPU_RESET_AL;
+	int ret;
+
+	ret = regmap_write(rtc->regmap, rtc->addr_base + RTC_BBPU, bbpu);
+	if (ret < 0) {
+		dev_err(rtc->rtc_dev->dev.parent, "%s: write rtc bbpu error\n",
+			__func__);
+		return;
+	}
+
+	mtk_rtc_write_trigger(rtc);
+}
+
 static irqreturn_t mtk_rtc_irq_handler_thread(int irq, void *data)
 {
 	struct mt6397_rtc *rtc = data;
@@ -51,6 +66,8 @@ static irqreturn_t mtk_rtc_irq_handler_thread(int irq, void *data)
 		if (regmap_write(rtc->regmap, rtc->addr_base + RTC_IRQ_EN,
 				 irqen) == 0)
 			mtk_rtc_write_trigger(rtc);
+
+		mtk_rtc_reset_bbpu_alarm_status(rtc);
 		mutex_unlock(&rtc->lock);
 
 		return IRQ_HANDLED;
@@ -297,6 +314,22 @@ static int mtk_rtc_probe(struct platform_device *pdev)
 	return devm_rtc_register_device(rtc->rtc_dev);
 }
 
+static void mtk_rtc_shutdown(struct platform_device *pdev)
+{
+	struct mt6397_rtc *rtc = platform_get_drvdata(pdev);
+	int ret = 0;
+
+	mtk_rtc_reset_bbpu_alarm_status(rtc);
+
+	ret = regmap_update_bits(rtc->regmap,
+				 rtc->addr_base + RTC_IRQ_EN,
+				 RTC_IRQ_EN_ONESHOT_AL, 0);
+	if (ret < 0)
+		return;
+
+	mtk_rtc_write_trigger(rtc);
+}
+
 #ifdef CONFIG_PM_SLEEP
 static int mt6397_rtc_suspend(struct device *dev)
 {
@@ -345,7 +378,8 @@ static struct platform_driver mtk_rtc_driver = {
 		.of_match_table = mt6397_rtc_of_match,
 		.pm = &mt6397_pm_ops,
 	},
-	.probe	= mtk_rtc_probe,
+	.probe = mtk_rtc_probe,
+	.shutdown = mtk_rtc_shutdown,
 };
 
 module_platform_driver(mtk_rtc_driver);
-- 
2.46.0

Re: [PATCH v1 2/2] rtc: mt6397: Add BBPU alarm status reset and shutdown handling

Posted by Alexandre Belloni 1 month, 3 weeks ago

On 11/08/2025 16:15:34+0800, ot_shunxi.zhang@mediatek.com wrote:
> From: Shunxi Zhang <ot_shunxi.zhang@mediatek.com>
> 
> This patch introduces a new function, mtk_rtc_reset_bbpu_alarm_status,
> to reset the BBPU alarm status in the MT6397 RTC driver. This function
> writes the necessary bits to the RTC_BBPU register to clear the alarm
> status and ensure proper operation.
> 
> Additionally, the mtk_rtc_shutdown function is added to handle RTC
> shutdown events. It resets the BBPU alarm status and updates the
> RTC_IRQ_EN register to disable the one-shot alarm interrupt,
> ensuring a clean shutdown process.
> 
> Signed-off-by: Shunxi Zhang <ot_shunxi.zhang@mediatek.com>
> ---
>  drivers/rtc/rtc-mt6397.c | 36 +++++++++++++++++++++++++++++++++++-
>  1 file changed, 35 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/rtc/rtc-mt6397.c b/drivers/rtc/rtc-mt6397.c
> index 692c00ff544b..063bd399de8c 100644
> --- a/drivers/rtc/rtc-mt6397.c
> +++ b/drivers/rtc/rtc-mt6397.c
> @@ -37,6 +37,21 @@ static int mtk_rtc_write_trigger(struct mt6397_rtc *rtc)
>  	return ret;
>  }
>  
> +static void mtk_rtc_reset_bbpu_alarm_status(struct mt6397_rtc *rtc)
> +{
> +	u32 bbpu = RTC_BBPU_KEY | RTC_BBPU_PWREN | RTC_BBPU_RESET_AL;
> +	int ret;
> +
> +	ret = regmap_write(rtc->regmap, rtc->addr_base + RTC_BBPU, bbpu);
> +	if (ret < 0) {
> +		dev_err(rtc->rtc_dev->dev.parent, "%s: write rtc bbpu error\n",
> +			__func__);
> +		return;
> +	}
> +
> +	mtk_rtc_write_trigger(rtc);
> +}
> +
>  static irqreturn_t mtk_rtc_irq_handler_thread(int irq, void *data)
>  {
>  	struct mt6397_rtc *rtc = data;
> @@ -51,6 +66,8 @@ static irqreturn_t mtk_rtc_irq_handler_thread(int irq, void *data)
>  		if (regmap_write(rtc->regmap, rtc->addr_base + RTC_IRQ_EN,
>  				 irqen) == 0)
>  			mtk_rtc_write_trigger(rtc);
> +
> +		mtk_rtc_reset_bbpu_alarm_status(rtc);
>  		mutex_unlock(&rtc->lock);
>  
>  		return IRQ_HANDLED;
> @@ -297,6 +314,22 @@ static int mtk_rtc_probe(struct platform_device *pdev)
>  	return devm_rtc_register_device(rtc->rtc_dev);
>  }
>  
> +static void mtk_rtc_shutdown(struct platform_device *pdev)
> +{
> +	struct mt6397_rtc *rtc = platform_get_drvdata(pdev);
> +	int ret = 0;
> +
> +	mtk_rtc_reset_bbpu_alarm_status(rtc);
> +
> +	ret = regmap_update_bits(rtc->regmap,
> +				 rtc->addr_base + RTC_IRQ_EN,
> +				 RTC_IRQ_EN_ONESHOT_AL, 0);
> +	if (ret < 0)
> +		return;
> +
> +	mtk_rtc_write_trigger(rtc);

The whole goal of the RTC is to wakeup the system, why would you disable
the alarm on shutdown?

> +}
> +
>  #ifdef CONFIG_PM_SLEEP
>  static int mt6397_rtc_suspend(struct device *dev)
>  {
> @@ -345,7 +378,8 @@ static struct platform_driver mtk_rtc_driver = {
>  		.of_match_table = mt6397_rtc_of_match,
>  		.pm = &mt6397_pm_ops,
>  	},
> -	.probe	= mtk_rtc_probe,
> +	.probe = mtk_rtc_probe,
> +	.shutdown = mtk_rtc_shutdown,
>  };
>  
>  module_platform_driver(mtk_rtc_driver);
> -- 
> 2.46.0
> 

-- 
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

Re: [PATCH v1 2/2] rtc: mt6397: Add BBPU alarm status reset and shutdown handling

Posted by Shunxi Zhang (章顺喜) 1 month, 2 weeks ago

On Mon, 2025-08-11 at 15:09 +0200, Alexandre Belloni wrote:
> External email : Please do not click links or open attachments until
> you have verified the sender or the content.
> 
> 
> On 11/08/2025 16:15:34+0800, ot_shunxi.zhang@mediatek.com wrote:
> > From: Shunxi Zhang <ot_shunxi.zhang@mediatek.com>
> > 
> > This patch introduces a new function,
> > mtk_rtc_reset_bbpu_alarm_status,
> > to reset the BBPU alarm status in the MT6397 RTC driver. This
> > function
> > writes the necessary bits to the RTC_BBPU register to clear the
> > alarm
> > status and ensure proper operation.
> > 
> > Additionally, the mtk_rtc_shutdown function is added to handle RTC
> > shutdown events. It resets the BBPU alarm status and updates the
> > RTC_IRQ_EN register to disable the one-shot alarm interrupt,
> > ensuring a clean shutdown process.
> > 
> > Signed-off-by: Shunxi Zhang <ot_shunxi.zhang@mediatek.com>
> > ---
> >  drivers/rtc/rtc-mt6397.c | 36 +++++++++++++++++++++++++++++++++++-
> >  1 file changed, 35 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/rtc/rtc-mt6397.c b/drivers/rtc/rtc-mt6397.c
> > index 692c00ff544b..063bd399de8c 100644
> > --- a/drivers/rtc/rtc-mt6397.c
> > +++ b/drivers/rtc/rtc-mt6397.c
> > @@ -37,6 +37,21 @@ static int mtk_rtc_write_trigger(struct
> > mt6397_rtc *rtc)
> >       return ret;
> >  }
> > 
> > +static void mtk_rtc_reset_bbpu_alarm_status(struct mt6397_rtc
> > *rtc)
> > +{
> > +     u32 bbpu = RTC_BBPU_KEY | RTC_BBPU_PWREN | RTC_BBPU_RESET_AL;
> > +     int ret;
> > +
> > +     ret = regmap_write(rtc->regmap, rtc->addr_base + RTC_BBPU,
> > bbpu);
> > +     if (ret < 0) {
> > +             dev_err(rtc->rtc_dev->dev.parent, "%s: write rtc bbpu
> > error\n",
> > +                     __func__);
> > +             return;
> > +     }
> > +
> > +     mtk_rtc_write_trigger(rtc);
> > +}
> > +
> >  static irqreturn_t mtk_rtc_irq_handler_thread(int irq, void *data)
> >  {
> >       struct mt6397_rtc *rtc = data;
> > @@ -51,6 +66,8 @@ static irqreturn_t mtk_rtc_irq_handler_thread(int
> > irq, void *data)
> >               if (regmap_write(rtc->regmap, rtc->addr_base +
> > RTC_IRQ_EN,
> >                                irqen) == 0)
> >                       mtk_rtc_write_trigger(rtc);
> > +
> > +             mtk_rtc_reset_bbpu_alarm_status(rtc);
> >               mutex_unlock(&rtc->lock);
> > 
> >               return IRQ_HANDLED;
> > @@ -297,6 +314,22 @@ static int mtk_rtc_probe(struct
> > platform_device *pdev)
> >       return devm_rtc_register_device(rtc->rtc_dev);
> >  }
> > 
> > +static void mtk_rtc_shutdown(struct platform_device *pdev)
> > +{
> > +     struct mt6397_rtc *rtc = platform_get_drvdata(pdev);
> > +     int ret = 0;
> > +
> > +     mtk_rtc_reset_bbpu_alarm_status(rtc);
> > +
> > +     ret = regmap_update_bits(rtc->regmap,
> > +                              rtc->addr_base + RTC_IRQ_EN,
> > +                              RTC_IRQ_EN_ONESHOT_AL, 0);
> > +     if (ret < 0)
> > +             return;
> > +
> > +     mtk_rtc_write_trigger(rtc);
> 
> The whole goal of the RTC is to wakeup the system, why would you
> disable
> the alarm on shutdown?

Dear sir,
  I will remove the flow of "disable alarm shutdown"
in next version. thanks for your comments.  

Best regards
shunxi zhang

> 
> > +}
> > +
> >  #ifdef CONFIG_PM_SLEEP
> >  static int mt6397_rtc_suspend(struct device *dev)
> >  {
> > @@ -345,7 +378,8 @@ static struct platform_driver mtk_rtc_driver =
> > {
> >               .of_match_table = mt6397_rtc_of_match,
> >               .pm = &mt6397_pm_ops,
> >       },
> > -     .probe  = mtk_rtc_probe,
> > +     .probe = mtk_rtc_probe,
> > +     .shutdown = mtk_rtc_shutdown,
> >  };
> > 
> >  module_platform_driver(mtk_rtc_driver);
> > --
> > 2.46.0
> > 
> 
> --
> Alexandre Belloni, co-owner and COO, Bootlin
> Embedded Linux and Kernel engineering
> 
https://urldefense.com/v3/__https://bootlin.com__;!!CTRNKA9wMg0ARbw!hGMitEEUU-sbH-rcMCMQ4Vlsn7NQeHdUrg9nEKYPyDME5fkbgsVciZd8SURxkvWA9Z1qX3oyNVZEWvVatYExZ8D7cFvdiyS_3Q_6$

[PATCH v1 1/2] mfd: mt6397: Add new bit definitions for RTC_BBPU register
[PATCH v1 2/2] rtc: mt6397: Add BBPU alarm status reset and shutdown handling