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>
This commit is contained in:
Jan Östlund 2016-08-11 13:31:44 +02:00 committed by Alexandre Belloni
parent 6ed1a51e0b
commit 421a5ba24b

View File

@ -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);