linux-kernel - [PATCH 4/6] rtc: pcf8563 Handle consequeces of lacking second alarm reg

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Date:	Mon, 27 Oct 2014 15:16:59 +0100
From:	Jan Kardell <jan.kardell@...liq.com>
To:	Alessandro Zummo <a.zummo@...ertech.it>,
	rtc-linux@...glegroups.com, linux-kernel@...r.kernel.org
Cc:	Vincent Donnefort <vdonnefort@...il.com>,
	Dan Carpenter <dan.carpenter@...cle.com>
Subject: [PATCH 4/6] rtc: pcf8563 Handle consequeces of lacking second alarm reg

To guarantee that a set alarm occurs in the future, the set alarm time
is rounded up to the nearest minute.
Also we cannot handle UIE as it requires second precision.

Signed-off-by: Jan Kardell <jan.kardell@...liq.com>
---
 drivers/rtc/rtc-pcf8563.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/rtc/rtc-pcf8563.c b/drivers/rtc/rtc-pcf8563.c
index 78f76d9..ce6a11b 100644
--- a/drivers/rtc/rtc-pcf8563.c
+++ b/drivers/rtc/rtc-pcf8563.c
@@ -361,6 +361,14 @@ static int pcf8563_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *tm)
 	struct i2c_client *client = to_i2c_client(dev);
 	unsigned char buf[4];
 	int err;
+	unsigned long alarm_time;
+
+	/* The alarm has no seconds, round up to nearest minute */
+	if (tm->time.tm_sec) {
+		rtc_tm_to_time(&tm->time, &alarm_time);
+		alarm_time += 60-tm->time.tm_sec;
+		rtc_time_to_tm(alarm_time, &tm->time);
+	}
 
 	dev_dbg(dev, "%s, min=%d hour=%d wday=%d mday=%d "
 		"enabled=%d pending=%d\n", __func__,
@@ -435,6 +443,9 @@ static int pcf8563_probe(struct i2c_client *client,
 
 	}
 
+	/* the pcf8563 alarm only supports a minute accuracy */
+	pcf8563->rtc->uie_unsupported = 1;
+
 	return 0;
 }
 
-- 
1.8.4.5

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