Some RTCs do provide a higher precision than seconds. Add support for them by trying rtc_read_timeval() before using rtc_read_time() to get the time in the hctosys mechanism.
Signed-off-by: Alexander Holler <[email protected]> --- drivers/rtc/class.c | 35 ++++++++++++++++++++++++----------- 1 file changed, 24 insertions(+), 11 deletions(-) diff --git a/drivers/rtc/class.c b/drivers/rtc/class.c index 625076b..1cdd506 100644 --- a/drivers/rtc/class.c +++ b/drivers/rtc/class.c @@ -150,16 +150,25 @@ static int rtc_resume(struct device *dev) static void hctosys(struct rtc_device *rtc) { struct rtc_time now; - struct timespec ts = { - .tv_nsec = NSEC_PER_SEC >> 1, - }; + struct timespec ts; + struct timeval tv = { 0, 0 }; int rc; - rc = rtc_read_time(rtc, &now); - if (unlikely(rc)) { - dev_err(rtc->dev.parent, - "rtc core: error reading time from RTC: %d\n", rc); - return; + rc = rtc_read_timeval(rtc, &tv); + if (rc || (!tv.tv_sec && !tv.tv_usec)) { + rc = rtc_read_time(rtc, &now); + if (unlikely(rc)) { + dev_err(rtc->dev.parent, + "rtc core: error reading time from RTC: %d\n", + rc); + return; + } + rtc_tm_to_time(&now, &ts.tv_sec); + ts.tv_nsec = NSEC_PER_SEC >> 1; + } else { + rtc_time_to_tm(tv.tv_sec, &now); + ts.tv_sec = tv.tv_sec; + ts.tv_nsec = tv.tv_usec*NSEC_PER_USEC; } rc = rtc_valid_tm(&now); if (unlikely(rc)) { @@ -167,7 +176,6 @@ static void hctosys(struct rtc_device *rtc) "rtc core: timestamp from RTC is invalid\n"); return; } - rtc_tm_to_time(&now, &ts.tv_sec); if (systime_was_set) return; rc = do_settimeofday(&ts); @@ -176,12 +184,17 @@ static void hctosys(struct rtc_device *rtc) "rtc core: error setting system clock: %d\n", rc); return; } else if (systime_was_set) { + char usbuf[8]; rtc_hctosys_dev_id = rtc->id; + if (tv.tv_sec) + snprintf(usbuf, sizeof(usbuf), ":%06ld", tv.tv_usec); + else + *usbuf = 0; dev_info(rtc->dev.parent, "rtc core: setting system clock to " - "%d-%02d-%02d %02d:%02d:%02d UTC (%u)\n", + "%d-%02d-%02d %02d:%02d:%02d%s UTC (%u)\n", now.tm_year + 1900, now.tm_mon + 1, now.tm_mday, - now.tm_hour, now.tm_min, now.tm_sec, + now.tm_hour, now.tm_min, now.tm_sec, usbuf, (unsigned int) ts.tv_sec); } } -- 1.8.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
