From 421a5ba24b3ef23b8972a6c238bd300abef532da Mon Sep 17 00:00:00 2001 From: =?utf8?q?Jan=20=C3=96stlund?= Date: Thu, 11 Aug 2016 13:31:44 +0200 Subject: [PATCH] rtc: bq32k: Fix handling of oscillator failure flag MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Signed-off-by: Daniel Romell Signed-off-by: Alexandre Belloni --- drivers/rtc/rtc-bq32k.c | 14 +++++++++----- 1 file 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, ®, BQ32K_MINUTES, 1); - if (!error && (reg & BQ32K_OF)) { - dev_warn(dev, "Oscillator Failure. Check RTC battery.\n"); - reg &= ~BQ32K_OF; - error = bq32k_write(dev, ®, 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); -- 2.20.1