From 76cb841cb886eef6b3bee341a2266c76578724ad Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Mon, 6 May 2024 03:02:30 +0200 Subject: Adding upstream version 4.19.249. Signed-off-by: Daniel Baumann --- drivers/rtc/systohc.c | 70 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 70 insertions(+) create mode 100644 drivers/rtc/systohc.c (limited to 'drivers/rtc/systohc.c') diff --git a/drivers/rtc/systohc.c b/drivers/rtc/systohc.c new file mode 100644 index 000000000..718293d72 --- /dev/null +++ b/drivers/rtc/systohc.c @@ -0,0 +1,70 @@ +/* + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published by + * the Free Software Foundation. + * + */ +#include +#include + +/** + * 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. + * + * Returns 0 on successful RTC update, -ENODEV if a RTC update is not + * 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, unsigned long *target_nsec) +{ + struct rtc_device *rtc; + struct rtc_time tm; + struct timespec64 to_set; + int err = -ENODEV; + bool ok; + + rtc = rtc_class_open(CONFIG_RTC_SYSTOHC_DEVICE); + 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; +} -- cgit v1.2.3