net: fec: fix MDIO bus assignement for dual fec SoC's
[deliverable/linux.git] / drivers / rtc / hctosys.c
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1/*
2 * RTC subsystem, initialize system time on startup
3 *
4 * Copyright (C) 2005 Tower Technologies
5 * Author: Alessandro Zummo <a.zummo@towertech.it>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10*/
11
12#include <linux/rtc.h>
13
14/* IMPORTANT: the RTC only stores whole seconds. It is arbitrary
15 * whether it stores the most close value or the value with partial
16 * seconds truncated. However, it is important that we use it to store
17 * the truncated value. This is because otherwise it is necessary,
18 * in an rtc sync function, to read both xtime.tv_sec and
19 * xtime.tv_nsec. On some processors (i.e. ARM), an atomic read
20 * of >32bits is not possible. So storing the most close value would
21 * slow down the sync API. So here we have the truncated value and
22 * the best guess is to add 0.5s.
23 */
24
25static int __init rtc_hctosys(void)
26{
d0ab4a4d 27 int err = -ENODEV;
0c86edc0 28 struct rtc_time tm;
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29 struct timespec tv = {
30 .tv_nsec = NSEC_PER_SEC >> 1,
31 };
ab6a2d70 32 struct rtc_device *rtc = rtc_class_open(CONFIG_RTC_HCTOSYS_DEVICE);
0c86edc0 33
ab6a2d70 34 if (rtc == NULL) {
d0ab4a4d 35 pr_err("%s: unable to open rtc device (%s)\n",
0c86edc0 36 __FILE__, CONFIG_RTC_HCTOSYS_DEVICE);
d0ab4a4d 37 goto err_open;
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38 }
39
ab6a2d70 40 err = rtc_read_time(rtc, &tm);
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41 if (err) {
42 dev_err(rtc->dev.parent,
43 "hctosys: unable to read the hardware clock\n");
44 goto err_read;
0c86edc0 45
d0ab4a4d 46 }
0c86edc0 47
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48 err = rtc_valid_tm(&tm);
49 if (err) {
50 dev_err(rtc->dev.parent,
51 "hctosys: invalid date/time\n");
52 goto err_invalid;
53 }
0c86edc0 54
d0ab4a4d 55 rtc_tm_to_time(&tm, &tv.tv_sec);
0c86edc0 56
4c24e29e 57 err = do_settimeofday(&tv);
0c86edc0 58
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59 dev_info(rtc->dev.parent,
60 "setting system clock to "
61 "%d-%02d-%02d %02d:%02d:%02d UTC (%u)\n",
62 tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
63 tm.tm_hour, tm.tm_min, tm.tm_sec,
64 (unsigned int) tv.tv_sec);
65
66err_invalid:
67err_read:
ab6a2d70 68 rtc_class_close(rtc);
0c86edc0 69
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70err_open:
71 rtc_hctosys_ret = err;
72
73 return err;
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74}
75
76late_initcall(rtc_hctosys);
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