As suggested by Uwe, instead of clearing oscillator failure bit
unconditionally at driver load, this patch adds proper handling
of the flag. The driver now returns -ENODATA when reading time
from the device and oscillator failure bit is set. The flag
is now cleared only when the a new time value is pushed to the
device.
Reported-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
Signed-off-by: Arnaud Ebalard <arno@xxxxxxxxxxxx>
---
drivers/rtc/rtc-isl12057.c | 47 ++++++++++++++++++++++++++++++++--------------
1 file changed, 33 insertions(+), 14 deletions(-)
diff --git a/drivers/rtc/rtc-isl12057.c b/drivers/rtc/rtc-isl12057.c
index b538fabfcfd3..fe562820a54a 100644
--- a/drivers/rtc/rtc-isl12057.c
+++ b/drivers/rtc/rtc-isl12057.c
@@ -164,17 +164,32 @@ static int isl12057_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct isl12057_rtc_data *data = dev_get_drvdata(dev);
u8 regs[ISL12057_RTC_SEC_LEN];
+ unsigned int sr;
int ret;
mutex_lock(&data->lock);
+ ret = regmap_read(data->regmap, ISL12057_REG_SR, &sr);
+ if (ret) {
+ dev_err(dev, "%s: unable to read oscillator status flag\n",
+ __func__);
+ goto out;
+ } else {
+ if (sr & ISL12057_REG_SR_OSF) {
+ ret = -ENODATA;
+ goto out;
+ }
+ }
+
ret = regmap_bulk_read(data->regmap, ISL12057_REG_RTC_SC, regs,
ISL12057_RTC_SEC_LEN);
+ if (ret)
+ dev_err(dev, "%s: unable to read RTC time\n", __func__);
+
+out:
mutex_unlock(&data->lock);
- if (ret) {
- dev_err(dev, "%s: RTC read failed\n", __func__);
+ if (ret)
return ret;
- }
isl12057_rtc_regs_to_tm(tm, regs);
@@ -194,10 +209,22 @@ static int isl12057_rtc_set_time(struct device *dev, struct rtc_time *tm)
mutex_lock(&data->lock);
ret = regmap_bulk_write(data->regmap, ISL12057_REG_RTC_SC, regs,
ISL12057_RTC_SEC_LEN);
- mutex_unlock(&data->lock);
+ if (ret) {
+ dev_err(dev, "%s: writing RTC time failed\n", __func__);
+ goto out;
+ }
- if (ret)
- dev_err(dev, "%s: RTC write failed\n", __func__);
+ /*
+ * Now that RTC time has been updated, let's clear oscillator
+ * failure flag, if needed.
+ */
+ ret = regmap_update_bits(data->regmap, ISL12057_REG_SR,
+ ISL12057_REG_SR_OSF, 0);
+ if (ret < 0)
+ dev_err(dev, "Unable to clear oscillator failure bit\n");
+
+out:
+ mutex_unlock(&data->lock);
return ret;
}
@@ -219,14 +246,6 @@ static int isl12057_check_rtc_status(struct device *dev, struct regmap *regmap)
return ret;
}
- /* Clear oscillator failure bit if needed */
- ret = regmap_update_bits(regmap, ISL12057_REG_SR,
- ISL12057_REG_SR_OSF, 0);
- if (ret < 0) {
- dev_err(dev, "Unable to clear oscillator failure bit\n");
- return ret;
- }
-
/* Clear alarm bit if needed */
ret = regmap_update_bits(regmap, ISL12057_REG_SR,
ISL12057_REG_SR_A1F, 0);
--
2.1.1
--
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