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authorJan Östlund <jao@hms.se>2016-08-11 13:31:44 +0200
committerAlexandre Belloni <alexandre.belloni@free-electrons.com>2016-08-31 18:21:35 +0200
commit421a5ba24b3ef23b8972a6c238bd300abef532da (patch)
tree0b620b64c90e540777d555411e0790d10f9ed6ed /drivers/rtc
parent6ed1a51e0b8a981ab0540117f0c47c1f11fca5fa (diff)
downloadtalos-obmc-linux-421a5ba24b3ef23b8972a6c238bd300abef532da.tar.gz
talos-obmc-linux-421a5ba24b3ef23b8972a6c238bd300abef532da.zip
rtc: bq32k: Fix handling of oscillator failure flag
While the oscillator failure flag is set, the RTC registers should be considered invalid. bq32k_rtc_read_time() now returns an error instead of an invalid time. The failure flag is cleared the next time the clock is set. Signed-off-by: Jan Östlund <jao@hms.se> Signed-off-by: Daniel Romell <daro@hms.se> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Diffstat (limited to 'drivers/rtc')
-rw-r--r--drivers/rtc/rtc-bq32k.c14
1 files changed, 9 insertions, 5 deletions
diff --git a/drivers/rtc/rtc-bq32k.c b/drivers/rtc/rtc-bq32k.c
index 5a0c13761023..397742446007 100644
--- a/drivers/rtc/rtc-bq32k.c
+++ b/drivers/rtc/rtc-bq32k.c
@@ -93,6 +93,13 @@ static int bq32k_rtc_read_time(struct device *dev, struct rtc_time *tm)
if (error)
return error;
+ /*
+ * In case of oscillator failure, the register contents should be
+ * considered invalid. The flag is cleared the next time the RTC is set.
+ */
+ if (regs.minutes & BQ32K_OF)
+ return -EINVAL;
+
tm->tm_sec = bcd2bin(regs.seconds & BQ32K_SECONDS_MASK);
tm->tm_min = bcd2bin(regs.minutes & BQ32K_MINUTES_MASK);
tm->tm_hour = bcd2bin(regs.cent_hours & BQ32K_HOURS_MASK);
@@ -204,13 +211,10 @@ static int bq32k_probe(struct i2c_client *client,
/* Check Oscillator Failure flag */
error = bq32k_read(dev, &reg, BQ32K_MINUTES, 1);
- if (!error && (reg & BQ32K_OF)) {
- dev_warn(dev, "Oscillator Failure. Check RTC battery.\n");
- reg &= ~BQ32K_OF;
- error = bq32k_write(dev, &reg, BQ32K_MINUTES, 1);
- }
if (error)
return error;
+ if (reg & BQ32K_OF)
+ dev_warn(dev, "Oscillator Failure. Check RTC battery.\n");
if (client->dev.of_node)
trickle_charger_of_init(dev, client->dev.of_node);
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