drivers/rtc/rtc-isl12057.c: add proper handling of oscillator failure bit
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.
Signed-off-by: Arnaud Ebalard <arno@natisbad.org>
Reported-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Acked-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Peter Huewe <peter.huewe@infineon.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Thierry Reding <treding@nvidia.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/rtc/rtc-isl12057.c b/drivers/rtc/rtc-isl12057.c
index b538fab..fe56282 100644
--- a/drivers/rtc/rtc-isl12057.c
+++ b/drivers/rtc/rtc-isl12057.c
@@ -164,17 +164,32 @@
{
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 @@
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 @@
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);