diff options
author | Thomas Gleixner <tglx@linutronix.de> | 2017-10-31 23:17:28 +0100 |
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committer | Thomas Gleixner <tglx@linutronix.de> | 2017-10-31 23:17:28 +0100 |
commit | fb56d689fb1c8f13d4d7168abf3838657b042885 (patch) | |
tree | a7e75f65e440d6c078c8e8eb25a2186c3c685261 /drivers | |
parent | 6c1e272f962da249f289846cec944bcd1c162a49 (diff) | |
parent | 6546911ed369af8d747215ff8b6144618e91c6ab (diff) | |
download | linux-fb56d689fb1c8f13d4d7168abf3838657b042885.tar.bz2 |
Merge branch 'fortglx/4.15/time' of https://git.linaro.org/people/john.stultz/linux into timers/core
Pull timekeeping updates from John Stultz:
- More y2038 work from Arnd Bergmann
- A new mechanism to allow RTC drivers to specify the resolution of the
RTC so the suspend/resume code can make informed decisions whether to
inject the suspended time or not in case of fast suspend/resume cycles.
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/rtc/class.c | 3 | ||||
-rw-r--r-- | drivers/rtc/systohc.c | 53 |
2 files changed, 41 insertions, 15 deletions
diff --git a/drivers/rtc/class.c b/drivers/rtc/class.c index 2ed970d61da1..722d683e0b0f 100644 --- a/drivers/rtc/class.c +++ b/drivers/rtc/class.c @@ -161,6 +161,9 @@ static struct rtc_device *rtc_allocate_device(void) device_initialize(&rtc->dev); + /* Drivers can revise this default after allocating the device. */ + rtc->set_offset_nsec = NSEC_PER_SEC / 2; + rtc->irq_freq = 1; rtc->max_user_freq = 64; rtc->dev.class = rtc_class; diff --git a/drivers/rtc/systohc.c b/drivers/rtc/systohc.c index b4a68ffcd06b..0c177647ea6c 100644 --- a/drivers/rtc/systohc.c +++ b/drivers/rtc/systohc.c @@ -10,6 +10,7 @@ /** * rtc_set_ntp_time - Save NTP synchronized time to the RTC * @now: Current time of day + * @target_nsec: pointer for desired now->tv_nsec value * * Replacement for the NTP platform function update_persistent_clock64 * that stores time for later retrieval by rtc_hctosys. @@ -18,30 +19,52 @@ * possible at all, and various other -errno for specific temporary failure * cases. * + * -EPROTO is returned if now.tv_nsec is not close enough to *target_nsec. + ( * If temporary failure is indicated the caller should try again 'soon' */ -int rtc_set_ntp_time(struct timespec64 now) +int rtc_set_ntp_time(struct timespec64 now, unsigned long *target_nsec) { struct rtc_device *rtc; struct rtc_time tm; + struct timespec64 to_set; int err = -ENODEV; - - if (now.tv_nsec < (NSEC_PER_SEC >> 1)) - rtc_time64_to_tm(now.tv_sec, &tm); - else - rtc_time64_to_tm(now.tv_sec + 1, &tm); + bool ok; rtc = rtc_class_open(CONFIG_RTC_SYSTOHC_DEVICE); - if (rtc) { - /* rtc_hctosys exclusively uses UTC, so we call set_time here, - * not set_mmss. */ - if (rtc->ops && - (rtc->ops->set_time || - rtc->ops->set_mmss64 || - rtc->ops->set_mmss)) - err = rtc_set_time(rtc, &tm); - rtc_class_close(rtc); + if (!rtc) + goto out_err; + + if (!rtc->ops || (!rtc->ops->set_time && !rtc->ops->set_mmss64 && + !rtc->ops->set_mmss)) + goto out_close; + + /* Compute the value of tv_nsec we require the caller to supply in + * now.tv_nsec. This is the value such that (now + + * set_offset_nsec).tv_nsec == 0. + */ + set_normalized_timespec64(&to_set, 0, -rtc->set_offset_nsec); + *target_nsec = to_set.tv_nsec; + + /* The ntp code must call this with the correct value in tv_nsec, if + * it does not we update target_nsec and return EPROTO to make the ntp + * code try again later. + */ + ok = rtc_tv_nsec_ok(rtc->set_offset_nsec, &to_set, &now); + if (!ok) { + err = -EPROTO; + goto out_close; } + rtc_time64_to_tm(to_set.tv_sec, &tm); + + /* rtc_hctosys exclusively uses UTC, so we call set_time here, not + * set_mmss. + */ + err = rtc_set_time(rtc, &tm); + +out_close: + rtc_class_close(rtc); +out_err: return err; } |