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: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220516082504.33913-4-miquel.raynal@bootlin.com
This commit is contained in:
Miquel Raynal 2022-05-16 10:25:02 +02:00 committed by Alexandre Belloni
parent deeb4b5393
commit b5ad1bf00d

View File

@ -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;