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-rw-r--r--arch/powerpc/sysdev/timer.c70
1 files changed, 70 insertions, 0 deletions
diff --git a/arch/powerpc/sysdev/timer.c b/arch/powerpc/sysdev/timer.c
new file mode 100644
index 000000000000..bdbf8fe520e4
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+++ b/arch/powerpc/sysdev/timer.c
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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 <asm/rtc.h>
11
12static unsigned long suspend_rtc_time;
13
14/*
15 * Reset the time after a sleep.
16 */
17static int timer_resume(struct sys_device *dev)
18{
19 struct timeval tv;
20 struct timespec ts;
21 struct rtc_time cur_rtc_tm;
22 unsigned long cur_rtc_time, diff;
23
24 /* get current RTC time and convert to seconds */
25 get_rtc_time(&cur_rtc_tm);
26 rtc_tm_to_time(&cur_rtc_tm, &cur_rtc_time);
27
28 diff = cur_rtc_time - suspend_rtc_time;
29
30 /* adjust time of day by seconds that elapsed while
31 * we were suspended */
32 do_gettimeofday(&tv);
33 ts.tv_sec = tv.tv_sec + diff;
34 ts.tv_nsec = tv.tv_usec * NSEC_PER_USEC;
35 do_settimeofday(&ts);
36
37 return 0;
38}
39
40static int timer_suspend(struct sys_device *dev, pm_message_t state)
41{
42 struct rtc_time suspend_rtc_tm;
43 WARN_ON(!ppc_md.get_rtc_time);
44
45 get_rtc_time(&suspend_rtc_tm);
46 rtc_tm_to_time(&suspend_rtc_tm, &suspend_rtc_time);
47
48 return 0;
49}
50
51static struct sysdev_class timer_sysclass = {
52 .resume = timer_resume,
53 .suspend = timer_suspend,
54 set_kset_name("timer"),
55};
56
57static struct sys_device device_timer = {
58 .id = 0,
59 .cls = &timer_sysclass,
60};
61
62static int time_init_device(void)
63{
64 int error = sysdev_class_register(&timer_sysclass);
65 if (!error)
66 error = sysdev_register(&device_timer);
67 return error;
68}
69
70device_initcall(time_init_device);