linux-kernel - Re: [PATCH 1/5] rtc: pm8xxx: implement no-alarm flag for non-HLOS owned alarm

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Message-ID: <20241011153758fd3f559d@mail.local>
Date: Fri, 11 Oct 2024 17:37:58 +0200
From: Alexandre Belloni <alexandre.belloni@...tlin.com>
To: Jonathan Marek <jonathan@...ek.ca>
Cc: linux-arm-msm@...r.kernel.org,
	"open list:REAL TIME CLOCK (RTC) SUBSYSTEM" <linux-rtc@...r.kernel.org>,
	open list <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 1/5] rtc: pm8xxx: implement no-alarm flag for non-HLOS
 owned alarm

On 11/10/2024 11:22:39-0400, Jonathan Marek wrote:
> Qualcomm x1e80100 firmware sets the ownership of the RTC alarm to ADSP.
> Thus writing to RTC alarm registers and receiving alarm interrupts is not
> possible.
> 
> Add a no-alarm flag to support RTC on this platform.
> 
> Signed-off-by: Jonathan Marek <jonathan@...ek.ca>
> ---
>  drivers/rtc/rtc-pm8xxx.c | 48 ++++++++++++++++++++++++++++------------
>  1 file changed, 34 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/rtc/rtc-pm8xxx.c b/drivers/rtc/rtc-pm8xxx.c
> index c32fba550c8e0..9240844022092 100644
> --- a/drivers/rtc/rtc-pm8xxx.c
> +++ b/drivers/rtc/rtc-pm8xxx.c
> @@ -61,6 +61,7 @@ struct pm8xxx_rtc {
>  	struct rtc_device *rtc;
>  	struct regmap *regmap;
>  	bool allow_set_time;
> +	bool no_alarm;
>  	int alarm_irq;
>  	const struct pm8xxx_rtc_regs *regs;
>  	struct device *dev;
> @@ -375,6 +376,11 @@ static const struct rtc_class_ops pm8xxx_rtc_ops = {
>  	.alarm_irq_enable = pm8xxx_rtc_alarm_irq_enable,
>  };
>  
> +static const struct rtc_class_ops pm8xxx_rtc_no_alarm_ops = {
> +	.read_time	= pm8xxx_rtc_read_time,
> +	.set_time	= pm8xxx_rtc_set_time,
> +};
> +

Please clear the alarm feature flag instead of duplicating the ops

>  static irqreturn_t pm8xxx_alarm_trigger(int irq, void *dev_id)
>  {
>  	struct pm8xxx_rtc *rtc_dd = dev_id;
> @@ -473,9 +479,13 @@ static int pm8xxx_rtc_probe(struct platform_device *pdev)
>  	if (!rtc_dd->regmap)
>  		return -ENXIO;
>  
> -	rtc_dd->alarm_irq = platform_get_irq(pdev, 0);
> -	if (rtc_dd->alarm_irq < 0)
> -		return -ENXIO;
> +	rtc_dd->no_alarm = of_property_read_bool(pdev->dev.of_node, "no-alarm");
> +
> +	if (!rtc_dd->no_alarm) {
> +		rtc_dd->alarm_irq = platform_get_irq(pdev, 0);
> +		if (rtc_dd->alarm_irq < 0)
> +			return -ENXIO;
> +	}
>  
>  	rtc_dd->allow_set_time = of_property_read_bool(pdev->dev.of_node,
>  						      "allow-set-time");
> @@ -503,7 +513,8 @@ static int pm8xxx_rtc_probe(struct platform_device *pdev)
>  
>  	platform_set_drvdata(pdev, rtc_dd);
>  
> -	device_init_wakeup(&pdev->dev, 1);
> +	if (!rtc_dd->no_alarm)
> +		device_init_wakeup(&pdev->dev, 1);
>  
>  	rtc_dd->rtc = devm_rtc_allocate_device(&pdev->dev);
>  	if (IS_ERR(rtc_dd->rtc))
> @@ -512,27 +523,36 @@ static int pm8xxx_rtc_probe(struct platform_device *pdev)
>  	rtc_dd->rtc->ops = &pm8xxx_rtc_ops;
>  	rtc_dd->rtc->range_max = U32_MAX;
>  
> -	rc = devm_request_any_context_irq(&pdev->dev, rtc_dd->alarm_irq,
> -					  pm8xxx_alarm_trigger,
> -					  IRQF_TRIGGER_RISING,
> -					  "pm8xxx_rtc_alarm", rtc_dd);
> -	if (rc < 0)
> -		return rc;
> +	if (!rtc_dd->no_alarm) {
> +		rc = devm_request_any_context_irq(&pdev->dev, rtc_dd->alarm_irq,
> +						  pm8xxx_alarm_trigger,
> +						  IRQF_TRIGGER_RISING,
> +						  "pm8xxx_rtc_alarm", rtc_dd);
> +		if (rc < 0)
> +			return rc;
> +	} else {
> +		rtc_dd->rtc->ops = &pm8xxx_rtc_no_alarm_ops;
> +	}
>  
>  	rc = devm_rtc_register_device(rtc_dd->rtc);
>  	if (rc)
>  		return rc;
>  
> -	rc = dev_pm_set_wake_irq(&pdev->dev, rtc_dd->alarm_irq);
> -	if (rc)
> -		return rc;
> +	if (!rtc_dd->no_alarm) {
> +		rc = dev_pm_set_wake_irq(&pdev->dev, rtc_dd->alarm_irq);
> +		if (rc)
> +			return rc;
> +	}
>  
>  	return 0;
>  }
>  
>  static void pm8xxx_remove(struct platform_device *pdev)
>  {
> -	dev_pm_clear_wake_irq(&pdev->dev);
> +	struct pm8xxx_rtc *rtc_dd = platform_get_drvdata(pdev);
> +
> +	if (!rtc_dd->no_alarm)
> +		dev_pm_clear_wake_irq(&pdev->dev);
>  }
>  
>  static struct platform_driver pm8xxx_rtc_driver = {
> -- 
> 2.45.1
> 

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