blob: bf3e242ccc5cdaf1231c091eb48310c1e61cf88e [file] [log] [blame]
Jason Gunthorpe023f3332012-12-17 14:30:53 -07001/*
2 * This program is free software; you can redistribute it and/or modify it
3 * under the terms of the GNU General Public License version 2 as published by
4 * the Free Software Foundation.
5 *
6 */
7#include <linux/rtc.h>
8#include <linux/time.h>
9
10/**
11 * rtc_set_ntp_time - Save NTP synchronized time to the RTC
12 * @now: Current time of day
13 *
14 * Replacement for the NTP platform function update_persistent_clock
15 * that stores time for later retrieval by rtc_hctosys.
16 *
17 * Returns 0 on successful RTC update, -ENODEV if a RTC update is not
18 * possible at all, and various other -errno for specific temporary failure
19 * cases.
20 *
21 * If temporary failure is indicated the caller should try again 'soon'
22 */
23int rtc_set_ntp_time(struct timespec now)
24{
25 struct rtc_device *rtc;
26 struct rtc_time tm;
27 int err = -ENODEV;
28
29 if (now.tv_nsec < (NSEC_PER_SEC >> 1))
30 rtc_time_to_tm(now.tv_sec, &tm);
31 else
32 rtc_time_to_tm(now.tv_sec + 1, &tm);
33
34 rtc = rtc_class_open(CONFIG_RTC_HCTOSYS_DEVICE);
35 if (rtc) {
36 /* rtc_hctosys exclusively uses UTC, so we call set_time here,
37 * not set_mmss. */
38 if (rtc->ops && (rtc->ops->set_time || rtc->ops->set_mmss))
39 err = rtc_set_time(rtc, &tm);
40 rtc_class_close(rtc);
41 }
42
43 return err;
44}