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

[Jonathan Marek <jonathan@marek.ca>]

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@marek.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,
+};
+
 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