diff options
| author | Alexandre Belloni <alexandre.belloni@free-electrons.com> | 2016-03-03 09:55:47 +0100 |
|---|---|---|
| committer | Alexandre Belloni <alexandre.belloni@free-electrons.com> | 2016-03-14 17:08:30 +0100 |
| commit | ede44c908d44b166a5b6bd7caacd105c2ff5a70f (patch) | |
| tree | c3917e54ee7928b6bda3d84578f1a9cfb3c68a86 /drivers/rtc/rtc-pcf8523.c | |
| parent | 2da424af4531c4469408136772d6d5e0f8df748b (diff) | |
| download | linux-ede44c908d44b166a5b6bd7caacd105c2ff5a70f.tar.bz2 | |
rtc: pcf8523: properly handle oscillator stop bit
The time and date register of the pcf8223 are undefined after a power
reset. Properly handle the OS bit and return -EINVAL when that bit is set.
It is properly removed when setting the time.
This solves an issue where the time and date may be valid for
rtc_valid_tm() but is not the current time.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Diffstat (limited to 'drivers/rtc/rtc-pcf8523.c')
| -rw-r--r-- | drivers/rtc/rtc-pcf8523.c | 25 |
1 files changed, 3 insertions, 22 deletions
diff --git a/drivers/rtc/rtc-pcf8523.c b/drivers/rtc/rtc-pcf8523.c index 988566caaaa6..28c48b3c1946 100644 --- a/drivers/rtc/rtc-pcf8523.c +++ b/drivers/rtc/rtc-pcf8523.c @@ -178,28 +178,8 @@ static int pcf8523_rtc_read_time(struct device *dev, struct rtc_time *tm) if (err < 0) return err; - if (regs[0] & REG_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] &= ~REG_SECONDS_OS; - - err = pcf8523_write(client, REG_SECONDS, regs[0]); - if (err < 0) - return err; - - err = pcf8523_read(client, REG_SECONDS, ®s[0]); - if (err < 0) - return err; - - if (regs[0] & REG_SECONDS_OS) - return -EAGAIN; - } + if (regs[0] & REG_SECONDS_OS) + return -EINVAL; tm->tm_sec = bcd2bin(regs[0] & 0x7f); tm->tm_min = bcd2bin(regs[1] & 0x7f); @@ -235,6 +215,7 @@ static int pcf8523_rtc_set_time(struct device *dev, struct rtc_time *tm) return err; regs[0] = REG_SECONDS; + /* This will purposely overwrite REG_SECONDS_OS */ regs[1] = bin2bcd(tm->tm_sec); regs[2] = bin2bcd(tm->tm_min); regs[3] = bin2bcd(tm->tm_hour); |