|  | /* | 
|  | * 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 <linux/rtc.h> | 
|  | #include <linux/time.h> | 
|  |  | 
|  | /** | 
|  | * rtc_set_ntp_time - Save NTP synchronized time to the RTC | 
|  | * @now: Current time of day | 
|  | * | 
|  | * Replacement for the NTP platform function update_persistent_clock | 
|  | * 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. | 
|  | * | 
|  | * If temporary failure is indicated the caller should try again 'soon' | 
|  | */ | 
|  | int rtc_set_ntp_time(struct timespec now) | 
|  | { | 
|  | struct rtc_device *rtc; | 
|  | struct rtc_time tm; | 
|  | int err = -ENODEV; | 
|  |  | 
|  | if (now.tv_nsec < (NSEC_PER_SEC >> 1)) | 
|  | rtc_time_to_tm(now.tv_sec, &tm); | 
|  | else | 
|  | rtc_time_to_tm(now.tv_sec + 1, &tm); | 
|  |  | 
|  | rtc = rtc_class_open(CONFIG_RTC_HCTOSYS_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_mmss)) | 
|  | err = rtc_set_time(rtc, &tm); | 
|  | rtc_class_close(rtc); | 
|  | } | 
|  |  | 
|  | return err; | 
|  | } |