[PATCH] rtc: opal: Implement rtc_class_ops.alarm_irq_enable callback

From: Vaibhav Jain
Date: Wed May 31 2017 - 09:11:07 EST


Provide an implementation of the callback
rtc_class_ops.alarm_irq_enable for rtc-opal driver. This callback is
called when the wake alarm is disabled via the command:

'echo 0 > /sys/class/rtc/rtc0/wakealarm'

Without this the Timed-Power-On(TPO) config remains set even when its
disabled by the above command and FSP will still force machine
boot at previously configured alarm time.

The callback is implemented as function opal_tpo_alarm_irq_enable()
which calls opal_set_tpo_time() with alarm.enabled == 0. A branch is
added to opal_set_tpo_time() to handle this case by passing y_m_d ==
h_m_s_ms == 0 to opal as arguments for opal_tpo_write() call.

Signed-off-by: Vaibhav Jain <vaibhav@xxxxxxxxxxxxxxxxxx>
---
drivers/rtc/rtc-opal.c | 22 +++++++++++++++++++++-
1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/drivers/rtc/rtc-opal.c b/drivers/rtc/rtc-opal.c
index 2d84e2a..e2a946c 100644
--- a/drivers/rtc/rtc-opal.c
+++ b/drivers/rtc/rtc-opal.c
@@ -167,7 +167,14 @@ static int opal_set_tpo_time(struct device *dev, struct rtc_wkalrm *alarm)
u32 y_m_d = 0;
int token, rc;

- tm_to_opal(&alarm->time, &y_m_d, &h_m_s_ms);
+ /* if alarm is enabled */
+ if (alarm->enabled) {
+ tm_to_opal(&alarm->time, &y_m_d, &h_m_s_ms);
+ pr_debug("Alarm set to %x %llx\n", y_m_d, h_m_s_ms);
+
+ } else {
+ pr_debug("Alarm getting disabled\n");
+ }

token = opal_async_get_token_interruptible();
if (token < 0) {
@@ -200,6 +207,18 @@ static int opal_set_tpo_time(struct device *dev, struct rtc_wkalrm *alarm)
return rc;
}

+int opal_tpo_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+ struct rtc_wkalrm alarm = { .enabled = 0 };
+
+ /*
+ * TPO is automatically enabled when opal_set_tpo_time() is called with
+ * non-zero rtc-time. We only handle disable case which needs to be
+ * explicitly told to opal.
+ */
+ return enabled ? 0 : opal_set_tpo_time(dev, &alarm);
+}
+
static struct rtc_class_ops opal_rtc_ops = {
.read_time = opal_get_rtc_time,
.set_time = opal_set_rtc_time,
@@ -215,6 +234,7 @@ static int opal_rtc_probe(struct platform_device *pdev)
device_set_wakeup_capable(&pdev->dev, true);
opal_rtc_ops.read_alarm = opal_get_tpo_time;
opal_rtc_ops.set_alarm = opal_set_tpo_time;
+ opal_rtc_ops.alarm_irq_enable = opal_tpo_alarm_irq_enable;
}

rtc = devm_rtc_device_register(&pdev->dev, DRVNAME, &opal_rtc_ops,
--
2.9.4