Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1/*
2 * Common code to keep time when machine suspends.
3 *
4 * Copyright 2007 Johannes Berg <johannes@sipsolutions.net>
5 *
6 * GPLv2
7 */
8
9#include <linux/time.h>
10#include <linux/sysdev.h>
11#include <asm/rtc.h>
12
13static unsigned long suspend_rtc_time;
14
15/*
16 * Reset the time after a sleep.
17 */
18static int timer_resume(struct sys_device *dev)
19{
20 struct timeval tv;
21 struct timespec ts;
22 struct rtc_time cur_rtc_tm;
23 unsigned long cur_rtc_time, diff;
24
25 /* get current RTC time and convert to seconds */
26 get_rtc_time(&cur_rtc_tm);
27 cur_rtc_time = mktime(cur_rtc_tm.tm_year + 1900,
28 cur_rtc_tm.tm_mon + 1,
29 cur_rtc_tm.tm_mday,
30 cur_rtc_tm.tm_hour,
31 cur_rtc_tm.tm_min,
32 cur_rtc_tm.tm_sec);
33
34 diff = cur_rtc_time - suspend_rtc_time;
35
36 /* adjust time of day by seconds that elapsed while
37 * we were suspended */
38 do_gettimeofday(&tv);
39 ts.tv_sec = tv.tv_sec + diff;
40 ts.tv_nsec = tv.tv_usec * NSEC_PER_USEC;
41 do_settimeofday(&ts);
42
43 return 0;
44}
45
46static int timer_suspend(struct sys_device *dev, pm_message_t state)
47{
48 struct rtc_time suspend_rtc_tm;
49 WARN_ON(!ppc_md.get_rtc_time);
50
51 get_rtc_time(&suspend_rtc_tm);
52 suspend_rtc_time = mktime(suspend_rtc_tm.tm_year + 1900,
53 suspend_rtc_tm.tm_mon + 1,
54 suspend_rtc_tm.tm_mday,
55 suspend_rtc_tm.tm_hour,
56 suspend_rtc_tm.tm_min,
57 suspend_rtc_tm.tm_sec);
58
59 return 0;
60}
61
62static struct sysdev_class timer_sysclass = {
63 .resume = timer_resume,
64 .suspend = timer_suspend,
65 set_kset_name("timer"),
66};
67
68static struct sys_device device_timer = {
69 .id = 0,
70 .cls = &timer_sysclass,
71};
72
73static int time_init_device(void)
74{
75 int error = sysdev_class_register(&timer_sysclass);
76 if (!error)
77 error = sysdev_register(&device_timer);
78 return error;
79}
80
81device_initcall(time_init_device);