{
struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
u8 regs[10];
+ u32 value;
int err;
err = regmap_bulk_read(pcf8523->regmap, PCF8523_REG_CONTROL1, regs,
if ((regs[0] & PCF8523_CONTROL1_STOP) || (regs[3] & PCF8523_SECONDS_OS))
return -EINVAL;
+ if (regs[0] & PCF8523_SECONDS_OS) {
+ /*
+ * If the oscillator was stopped, try to clear the flag. Upon
+ * power-up the flag is always set, but if we cannot clear it
+ * the oscillator isn't running properly for some reason. The
+ * sensible thing therefore is to return an error, signalling
+ * that the clock cannot be assumed to be correct.
+ */
+
+ regs[0] &= ~PCF8523_SECONDS_OS;
+
+ err = regmap_write(pcf8523->regmap, PCF8523_REG_SECONDS,
+ regs[0]);
+ if (err < 0)
+ return err;
+
+ err = regmap_read(pcf8523->regmap, PCF8523_REG_SECONDS,
+ &value);
+ if (err < 0)
+ return err;
+
+ if (value & PCF8523_SECONDS_OS)
+ return -EAGAIN;
+
+ regs[0] = value;
+ }
+
tm->tm_sec = bcd2bin(regs[3] & 0x7f);
tm->tm_min = bcd2bin(regs[4] & 0x7f);
tm->tm_hour = bcd2bin(regs[5] & 0x3f);