Commit b5ad1bf0 authored by Miquel Raynal's avatar Miquel Raynal Committed by Alexandre Belloni
Browse files

rtc: rzn1: Add alarm support 



The RZN1 RTC can trigger an interrupt when reaching a particular date up
to 7 days ahead. Bring support for this alarm.

One drawback though, the granularity is about a minute.

Signed-off-by: default avatarMiquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: default avatarAlexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220516082504.33913-4-miquel.raynal@bootlin.com
parent deeb4b53

drivers/rtc/rtc-rzn1.c

+105 −1
Original line number Diff line number Diff line
@@ -156,14 +156,107 @@ static int rzn1_rtc_set_time(struct device *dev, struct rtc_time *tm) 
	return 0;

}



static irqreturn_t rzn1_rtc_alarm_irq(int irq, void *dev_id)

{

	struct rzn1_rtc *rtc = dev_id;



	rtc_update_irq(rtc->rtcdev, 1, RTC_AF | RTC_IRQF);



	return IRQ_HANDLED;

}



static int rzn1_rtc_alarm_irq_enable(struct device *dev, unsigned int enable)

{

	struct rzn1_rtc *rtc = dev_get_drvdata(dev);

	u32 ctl1 = readl(rtc->base + RZN1_RTC_CTL1);



	if (enable)

		ctl1 |= RZN1_RTC_CTL1_ALME;

	else

		ctl1 &= ~RZN1_RTC_CTL1_ALME;



	writel(ctl1, rtc->base + RZN1_RTC_CTL1);



	return 0;

}



static int rzn1_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)

{

	struct rzn1_rtc *rtc = dev_get_drvdata(dev);

	struct rtc_time *tm = &alrm->time;

	unsigned int min, hour, wday, delta_days;

	time64_t alarm;

	u32 ctl1;

	int ret;



	ret = rzn1_rtc_read_time(dev, tm);

	if (ret)

		return ret;



	min = readl(rtc->base + RZN1_RTC_ALM);

	hour = readl(rtc->base + RZN1_RTC_ALH);

	wday = readl(rtc->base + RZN1_RTC_ALW);



	tm->tm_sec = 0;

	tm->tm_min = bcd2bin(min);

	tm->tm_hour = bcd2bin(hour);

	delta_days = ((fls(wday) - 1) - tm->tm_wday + 7) % 7;

	tm->tm_wday = fls(wday) - 1;



	if (delta_days) {

		alarm = rtc_tm_to_time64(tm) + (delta_days * 86400);

		rtc_time64_to_tm(alarm, tm);

	}



	ctl1 = readl(rtc->base + RZN1_RTC_CTL1);

	alrm->enabled = !!(ctl1 & RZN1_RTC_CTL1_ALME);



	return 0;

}



static int rzn1_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)

{

	struct rzn1_rtc *rtc = dev_get_drvdata(dev);

	struct rtc_time *tm = &alrm->time, tm_now;

	unsigned long alarm, farest;

	unsigned int days_ahead, wday;

	int ret;



	ret = rzn1_rtc_read_time(dev, &tm_now);

	if (ret)

		return ret;



	/* We cannot set alarms more than one week ahead */

	farest = rtc_tm_to_time64(&tm_now) + (7 * 86400);

	alarm = rtc_tm_to_time64(tm);

	if (time_after(alarm, farest))

		return -ERANGE;



	/* Convert alarm day into week day */

	days_ahead = tm->tm_mday - tm_now.tm_mday;

	wday = (tm_now.tm_wday + days_ahead) % 7;



	writel(bin2bcd(tm->tm_min), rtc->base + RZN1_RTC_ALM);

	writel(bin2bcd(tm->tm_hour), rtc->base + RZN1_RTC_ALH);

	writel(BIT(wday), rtc->base + RZN1_RTC_ALW);



	rzn1_rtc_alarm_irq_enable(dev, alrm->enabled);



	return 0;

}



static const struct rtc_class_ops rzn1_rtc_ops = {

	.read_time = rzn1_rtc_read_time,

	.set_time = rzn1_rtc_set_time,

	.read_alarm = rzn1_rtc_read_alarm,

	.set_alarm = rzn1_rtc_set_alarm,

	.alarm_irq_enable = rzn1_rtc_alarm_irq_enable,

};



static int rzn1_rtc_probe(struct platform_device *pdev)

{

	struct rzn1_rtc *rtc;

	int alarm_irq;

	int ret;



	rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
@@ -176,6 +269,10 @@ static int rzn1_rtc_probe(struct platform_device *pdev) 
	if (IS_ERR(rtc->base))

		return dev_err_probe(&pdev->dev, PTR_ERR(rtc->base), "Missing reg\n");



	alarm_irq = platform_get_irq(pdev, 0);

	if (alarm_irq < 0)

		return alarm_irq;



	rtc->rtcdev = devm_rtc_allocate_device(&pdev->dev);

	if (IS_ERR(rtc->rtcdev))

		return PTR_ERR(rtc);
@@ -183,7 +280,7 @@ static int rzn1_rtc_probe(struct platform_device *pdev) 
	rtc->rtcdev->range_min = RTC_TIMESTAMP_BEGIN_2000;

	rtc->rtcdev->range_max = RTC_TIMESTAMP_END_2099;

	rtc->rtcdev->ops = &rzn1_rtc_ops;

	clear_bit(RTC_FEATURE_ALARM, rtc->rtcdev->features);

	set_bit(RTC_FEATURE_ALARM_RES_MINUTE, rtc->rtcdev->features);

	clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->rtcdev->features);



	devm_pm_runtime_enable(&pdev->dev);
@@ -201,6 +298,13 @@ static int rzn1_rtc_probe(struct platform_device *pdev) 
	/* Disable all interrupts */

	writel(0, rtc->base + RZN1_RTC_CTL1);



	ret = devm_request_irq(&pdev->dev, alarm_irq, rzn1_rtc_alarm_irq, 0,

			       dev_name(&pdev->dev), rtc);

	if (ret) {

		dev_err(&pdev->dev, "RTC timer interrupt not available\n");

		goto dis_runtime_pm;

	}



	ret = devm_rtc_register_device(rtc->rtcdev);

	if (ret)

		goto dis_runtime_pm;