rtc: pcf8563: clear expired alarm at boot time

In case the card is woken up of the rtc alarm, the
devm_rtc_device_register function detects it as a pending alarm about a
month in the future.  Fix this by clearing the alarm in module probe.

Signed-off-by: Jan Kardell <jan.kardell@telliq.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Vincent Donnefort <vdonnefort@gmail.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/rtc/rtc-pcf8563.c b/drivers/rtc/rtc-pcf8563.c
index 1e14f609db34cca31be1d5b0e3eb652e99f17692..96fb32e7d6f8af04c6a78ecb2e65c35e48b89c48 100644 (file)
--- a/drivers/rtc/rtc-pcf8563.c
+++ b/drivers/rtc/rtc-pcf8563.c
@@ -396,6 +396,7 @@ static int pcf8563_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *tm)
 
 static int pcf8563_irq_enable(struct device *dev, unsigned int enabled)
 {
+       dev_dbg(dev, "%s: en=%d\n", __func__, enabled);
        return pcf8563_set_alarm_mode(to_i2c_client(dev), !!enabled);
 }
 
@@ -414,6 +415,7 @@ static int pcf8563_probe(struct i2c_client *client,
        struct pcf8563 *pcf8563;
        int err;
        unsigned char buf;
+       unsigned char alm_pending;
 
        dev_dbg(&client->dev, "%s\n", __func__);
 
@@ -439,6 +441,14 @@ static int pcf8563_probe(struct i2c_client *client,
                return err;
        }
 
+       err = pcf8563_get_alarm_mode(client, NULL, &alm_pending);
+       if (err < 0) {
+               dev_err(&client->dev, "%s: read error\n", __func__);
+               return err;
+       }
+       if (alm_pending)
+               pcf8563_set_alarm_mode(client, 0);
+
        pcf8563->rtc = devm_rtc_device_register(&client->dev,
                                pcf8563_driver.driver.name,
                                &pcf8563_rtc_ops, THIS_MODULE);