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12#include <linux/rtc.h>
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25int rtc_hctosys_ret = -ENODEV;
26
27static int __init rtc_hctosys(void)
28{
29 int err = -ENODEV;
30 struct rtc_time tm;
31 struct timespec tv = {
32 .tv_nsec = NSEC_PER_SEC >> 1,
33 };
34 struct rtc_device *rtc = rtc_class_open(CONFIG_RTC_HCTOSYS_DEVICE);
35
36 if (rtc == NULL) {
37 pr_err("%s: unable to open rtc device (%s)\n",
38 __FILE__, CONFIG_RTC_HCTOSYS_DEVICE);
39 goto err_open;
40 }
41
42 err = rtc_read_time(rtc, &tm);
43 if (err) {
44 dev_err(rtc->dev.parent,
45 "hctosys: unable to read the hardware clock\n");
46 goto err_read;
47
48 }
49
50 err = rtc_valid_tm(&tm);
51 if (err) {
52 dev_err(rtc->dev.parent,
53 "hctosys: invalid date/time\n");
54 goto err_invalid;
55 }
56
57 rtc_tm_to_time(&tm, &tv.tv_sec);
58
59 do_settimeofday(&tv);
60
61 dev_info(rtc->dev.parent,
62 "setting system clock to "
63 "%d-%02d-%02d %02d:%02d:%02d UTC (%u)\n",
64 tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
65 tm.tm_hour, tm.tm_min, tm.tm_sec,
66 (unsigned int) tv.tv_sec);
67
68err_invalid:
69err_read:
70 rtc_class_close(rtc);
71
72err_open:
73 rtc_hctosys_ret = err;
74
75 return err;
76}
77
78late_initcall(rtc_hctosys);
79