Merge master.kernel.org:/pub/scm/linux/kernel/git/jejb/voyager-2.6
[linux-2.6] / arch / powerpc / sysdev / timer.c
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
13 static unsigned long suspend_rtc_time;
14
15 /*
16  * Reset the time after a sleep.
17  */
18 static 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         rtc_tm_to_time(&cur_rtc_tm, &cur_rtc_time);
28
29         diff = cur_rtc_time - suspend_rtc_time;
30
31         /* adjust time of day by seconds that elapsed while
32          * we were suspended */
33         do_gettimeofday(&tv);
34         ts.tv_sec = tv.tv_sec + diff;
35         ts.tv_nsec = tv.tv_usec * NSEC_PER_USEC;
36         do_settimeofday(&ts);
37
38         return 0;
39 }
40
41 static int timer_suspend(struct sys_device *dev, pm_message_t state)
42 {
43         struct rtc_time suspend_rtc_tm;
44         WARN_ON(!ppc_md.get_rtc_time);
45
46         get_rtc_time(&suspend_rtc_tm);
47         rtc_tm_to_time(&suspend_rtc_tm, &suspend_rtc_time);
48
49         return 0;
50 }
51
52 static struct sysdev_class timer_sysclass = {
53         .resume = timer_resume,
54         .suspend = timer_suspend,
55         set_kset_name("timer"),
56 };
57
58 static struct sys_device device_timer = {
59         .id = 0,
60         .cls = &timer_sysclass,
61 };
62
63 static int time_init_device(void)
64 {
65         int error = sysdev_class_register(&timer_sysclass);
66         if (!error)
67                 error = sysdev_register(&device_timer);
68         return error;
69 }
70
71 device_initcall(time_init_device);