On 30/08/2024 16:02:12+0300, Claudiu wrote:

+	priv->rtc_dev->range_min = mktime64(2000, 1, 1, 0, 0, 0);

RTC_TIMESTAMP_BEGIN_2000

+	priv->rtc_dev->range_max = mktime64(2099, 12, 31, 23, 59, 59);

RTC_TIMESTAMP_END_2099

+
+	return devm_rtc_register_device(priv->rtc_dev);
+}
+
+static void rtca3_remove(struct platform_device *pdev)
+{
+	struct rtca3_priv *priv = platform_get_drvdata(pdev);
+
+	guard(spinlock_irqsave)(&priv->lock);
+
+	/* Disable alarm, periodic interrupts. */
+	rtca3_alarm_irq_set_helper(priv, RTCA3_RCR1_AIE | RTCA3_RCR1_PIE, 0);

Why do you disable alarms on driver remove? I think you need to add a
comment if this is because it can't system up, else this is a bad
practice.

+
+static int rtca3_clean_alarm(struct rtca3_priv *priv)
+{
+	struct rtc_device *rtc_dev = priv->rtc_dev;
+	time64_t alarm_time, now;
+	struct rtc_wkalrm alarm;
+	struct rtc_time tm;
+	u8 pending;
+	int ret;
+
+	ret = rtc_read_alarm(rtc_dev, &alarm);
+	if (ret)
+		return ret;
+
+	if (!alarm.enabled)
+		return 0;
+
+	ret = rtc_read_time(rtc_dev, &tm);
+	if (ret)
+		return ret;
+
+	alarm_time = rtc_tm_to_time64(&alarm.time);
+	now = rtc_tm_to_time64(&tm);
+	if (alarm_time >= now)
+		return 0;
+
+	/*
+	 * Heuristically, it has been determined that when returning from deep
+	 * sleep state the RTCA3_RSR.AF is zero even though the alarm expired.
+	 * Call again the rtc_update_irq() if alarm helper detects this.
+	 */
+
+	guard(spinlock_irqsave)(&priv->lock);
+
+	pending = rtca3_alarm_handler_helper(priv);
+	if (!pending)
+		rtc_update_irq(priv->rtc_dev, 1, RTC_AF | RTC_IRQF);
+
+	return 0;
+}
+
+static int rtca3_resume(struct device *dev)
+{
+	struct rtca3_priv *priv = dev_get_drvdata(dev);
+
+	if (!device_may_wakeup(dev))
+		return 0;
+
+	disable_irq_wake(priv->wakeup_irq);
+
+	/*
+	 * According to the HW manual (section 22.6.4 Notes on writing to
+	 * and reading from registers) we need to wait 1/128 seconds while
+	 * RCR2.START = 1 to be able to read the counters after a return from low
+	 * power consumption state.
+	 */
+	mdelay(8);
+
+	/*
+	 * The alarm cannot wake the system from deep sleep states. In case
+	 * we return from deep sleep states and the alarm expired we need
+	 * to disable it to avoid failures when setting another alarm.
+	 */
+	return rtca3_clean_alarm(priv);
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(rtca3_pm_ops, rtca3_suspend, rtca3_resume);
+
+static const struct of_device_id rtca3_of_match[] = {
+	{ .compatible = "renesas,rz-rtca3", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, rtca3_of_match);
+
+static struct platform_driver rtca3_platform_driver = {
+	.driver = {
+		.name = "rtc-rtca3",
+		.pm = pm_ptr(&rtca3_pm_ops),
+		.of_match_table = rtca3_of_match,
+	},
+	.probe = rtca3_probe,
+	.remove_new = rtca3_remove,
+};
+module_platform_driver(rtca3_platform_driver);
+
+MODULE_DESCRIPTION("Renesas RTCA-3 RTC driver");
+MODULE_AUTHOR("Claudiu Beznea [off-list ref]");
+MODULE_LICENSE("GPL");
-- 
2.39.2

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