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linux-next/drivers/rtc/systohc.c
Xunlei Pang 8e4ff1a81a drivers/rtc: Provide y2038 safe rtc_class_ops.set_mmss() replacement
Currently the rtc_class_op's set_mmss() function takes a 32-bit
second value (on 32-bit systems), which is problematic for dates
past y2038.

This patch provides a safe version named set_mmss64() using
y2038 safe time64_t.

After this patch, set_mmss() is deprecated and all its users
will be fixed to use set_mmss64(), it can be removed when having
no users.

Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org>
[jstultz: Add whitespace fix for checkpatch]
Signed-off-by: John Stultz <john.stultz@linaro.org>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1427945681-29972-8-git-send-email-john.stultz@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-03 08:18:24 +02:00

48 lines
1.2 KiB
C

/*
* 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_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.
*
* If temporary failure is indicated the caller should try again 'soon'
*/
int rtc_set_ntp_time(struct timespec64 now)
{
struct rtc_device *rtc;
struct rtc_time tm;
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);
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_mmss64 ||
rtc->ops->set_mmss))
err = rtc_set_time(rtc, &tm);
rtc_class_close(rtc);
}
return err;
}