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Mike Frysinger6b160e42008-02-15 02:27:19 +00001/*
2 * rtcwake -- enter a system sleep state until specified wakeup time.
3 *
4 * This version was taken from util-linux and scrubbed down for busybox.
5 *
Denys Vlasenko0ef64bd2010-08-16 20:14:46 +02006 * Licensed under GPLv2, see file LICENSE in this source tree.
Denis Vlasenkodb12d1d2008-12-07 00:52:58 +00007 *
Mike Frysinger6b160e42008-02-15 02:27:19 +00008 * This uses cross-platform Linux interfaces to enter a system sleep state,
9 * and leave it no later than a specified time. It uses any RTC framework
10 * driver that supports standard driver model wakeup flags.
11 *
12 * This is normally used like the old "apmsleep" utility, to wake from a
13 * suspend state like ACPI S1 (standby) or S3 (suspend-to-RAM). Most
14 * platforms can implement those without analogues of BIOS, APM, or ACPI.
15 *
16 * On some systems, this can also be used like "nvram-wakeup", waking
17 * from states like ACPI S4 (suspend to disk). Not all systems have
18 * persistent media that are appropriate for such suspend modes.
19 *
20 * The best way to set the system's RTC is so that it holds the current
21 * time in UTC. Use the "-l" flag to tell this program that the system
22 * RTC uses a local timezone instead (maybe you dual-boot MS-Windows).
23 * That flag should not be needed on systems with adjtime support.
24 */
Denys Vlasenkodd898c92016-11-23 11:46:32 +010025//config:config RTCWAKE
Denys Vlasenkob097a842018-12-28 03:20:17 +010026//config: bool "rtcwake (6.8 kb)"
Denys Vlasenkodd898c92016-11-23 11:46:32 +010027//config: default y
Denys Vlasenkodd898c92016-11-23 11:46:32 +010028//config: help
Denys Vlasenko72089cf2017-07-21 09:50:55 +020029//config: Enter a system sleep state until specified wakeup time.
Denys Vlasenkodd898c92016-11-23 11:46:32 +010030
31//applet:IF_RTCWAKE(APPLET(rtcwake, BB_DIR_USR_SBIN, BB_SUID_DROP))
32
33//kbuild:lib-$(CONFIG_RTCWAKE) += rtcwake.o
Mike Frysinger6b160e42008-02-15 02:27:19 +000034
Pere Orga5bc8c002011-04-11 03:29:49 +020035//usage:#define rtcwake_trivial_usage
36//usage: "[-a | -l | -u] [-d DEV] [-m MODE] [-s SEC | -t TIME]"
37//usage:#define rtcwake_full_usage "\n\n"
38//usage: "Enter a system sleep state until specified wakeup time\n"
Denys Vlasenkocaba1a12020-12-16 01:19:08 +010039//usage: "\n -a Read clock mode from "ADJTIME_PATH" (default)"
Pere Orga5bc8c002011-04-11 03:29:49 +020040//usage: "\n -l Clock is set to local time"
41//usage: "\n -u Clock is set to UTC time"
42//usage: "\n -d DEV Specify the RTC device"
Denys Vlasenko54e95852015-02-18 13:47:27 +010043//usage: "\n -m MODE Set sleep state (default: standby)"
44//usage: "\n -s SEC Set timeout in SEC seconds from now"
45//usage: "\n -t TIME Set timeout to TIME seconds from epoch"
Pere Orga5bc8c002011-04-11 03:29:49 +020046
Mike Frysinger6b160e42008-02-15 02:27:19 +000047#include "libbb.h"
48#include "rtc_.h"
49
50#define SYS_RTC_PATH "/sys/class/rtc/%s/device/power/wakeup"
51#define SYS_POWER_PATH "/sys/power/state"
Mike Frysinger6b160e42008-02-15 02:27:19 +000052
Denys Vlasenkoadf922e2009-10-08 14:35:37 +020053static NOINLINE bool may_wakeup(const char *rtcname)
Mike Frysinger6b160e42008-02-15 02:27:19 +000054{
55 ssize_t ret;
56 char buf[128];
57
Denys Vlasenkof8d8aa12010-04-06 18:50:05 +020058 /* strip "/dev/" from the rtcname here */
59 rtcname = skip_dev_pfx(rtcname);
Mike Frysinger6b160e42008-02-15 02:27:19 +000060
61 snprintf(buf, sizeof(buf), SYS_RTC_PATH, rtcname);
62 ret = open_read_close(buf, buf, sizeof(buf));
63 if (ret < 0)
Bernhard Reutner-Fischerae4342c2008-05-19 08:18:50 +000064 return false;
Mike Frysinger6b160e42008-02-15 02:27:19 +000065
66 /* wakeup events could be disabled or not supported */
Denys Vlasenko8dff01d2015-03-12 17:48:34 +010067 return is_prefixed_with(buf, "enabled\n") != NULL;
Mike Frysinger6b160e42008-02-15 02:27:19 +000068}
69
Denys Vlasenko784d0952009-10-08 16:04:50 +020070static NOINLINE void setup_alarm(int fd, time_t *wakeup, time_t rtc_time)
Mike Frysinger6b160e42008-02-15 02:27:19 +000071{
Denys Vlasenkodc698bb2010-01-09 19:10:49 +010072 struct tm *ptm;
Denys Vlasenkoe4dcba12010-10-28 18:57:19 +020073 struct linux_rtc_wkalrm wake;
Mike Frysinger6b160e42008-02-15 02:27:19 +000074
75 /* The wakeup time is in POSIX time (more or less UTC).
76 * Ideally RTCs use that same time; but PCs can't do that
77 * if they need to boot MS-Windows. Messy...
78 *
79 * When running in utc mode this process's timezone is UTC,
80 * so we'll pass a UTC date to the RTC.
81 *
82 * Else mode is local so the time given to the RTC
83 * will instead use the local time zone.
84 */
Denys Vlasenkodc698bb2010-01-09 19:10:49 +010085 ptm = localtime(wakeup);
Mike Frysinger6b160e42008-02-15 02:27:19 +000086
Denys Vlasenkodc698bb2010-01-09 19:10:49 +010087 wake.time.tm_sec = ptm->tm_sec;
88 wake.time.tm_min = ptm->tm_min;
89 wake.time.tm_hour = ptm->tm_hour;
90 wake.time.tm_mday = ptm->tm_mday;
91 wake.time.tm_mon = ptm->tm_mon;
92 wake.time.tm_year = ptm->tm_year;
Mike Frysinger6b160e42008-02-15 02:27:19 +000093 /* wday, yday, and isdst fields are unused by Linux */
94 wake.time.tm_wday = -1;
95 wake.time.tm_yday = -1;
96 wake.time.tm_isdst = -1;
97
98 /* many rtc alarms only support up to 24 hours from 'now',
99 * so use the "more than 24 hours" request only if we must
100 */
101 if ((rtc_time + (24 * 60 * 60)) > *wakeup) {
102 xioctl(fd, RTC_ALM_SET, &wake.time);
103 xioctl(fd, RTC_AIE_ON, 0);
104 } else {
105 /* avoid an extra AIE_ON call */
106 wake.enabled = 1;
107 xioctl(fd, RTC_WKALM_SET, &wake);
108 }
109}
110
Mike Frysinger6b160e42008-02-15 02:27:19 +0000111#define RTCWAKE_OPT_AUTO 0x01
112#define RTCWAKE_OPT_LOCAL 0x02
113#define RTCWAKE_OPT_UTC 0x04
114#define RTCWAKE_OPT_DEVICE 0x08
115#define RTCWAKE_OPT_SUSPEND_MODE 0x10
116#define RTCWAKE_OPT_SECONDS 0x20
117#define RTCWAKE_OPT_TIME 0x40
118
119int rtcwake_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
Denis Vlasenkoa60f84e2008-07-05 09:18:54 +0000120int rtcwake_main(int argc UNUSED_PARAM, char **argv)
Mike Frysinger6b160e42008-02-15 02:27:19 +0000121{
122 unsigned opt;
123 const char *rtcname = NULL;
Denys Vlasenkoa4476eb2014-05-02 12:46:15 +0200124 const char *suspend = "standby";
Mike Frysinger6b160e42008-02-15 02:27:19 +0000125 const char *opt_seconds;
126 const char *opt_time;
127
Denys Vlasenkoa4476eb2014-05-02 12:46:15 +0200128 time_t rtc_time;
Mike Frysinger6b160e42008-02-15 02:27:19 +0000129 time_t sys_time;
Denys Vlasenkoa4476eb2014-05-02 12:46:15 +0200130 time_t alarm_time = alarm_time;
131 unsigned seconds = seconds; /* for compiler */
Mike Frysinger6b160e42008-02-15 02:27:19 +0000132 int utc = -1;
133 int fd;
134
Denys Vlasenkof3b92d32009-06-19 12:10:38 +0200135#if ENABLE_LONG_OPTS
Mike Frysingerea915362008-02-15 02:33:22 +0000136 static const char rtcwake_longopts[] ALIGN1 =
137 "auto\0" No_argument "a"
138 "local\0" No_argument "l"
139 "utc\0" No_argument "u"
140 "device\0" Required_argument "d"
141 "mode\0" Required_argument "m"
142 "seconds\0" Required_argument "s"
143 "time\0" Required_argument "t"
144 ;
Mike Frysinger6b160e42008-02-15 02:27:19 +0000145#endif
Denys Vlasenko22542ec2017-08-08 21:55:02 +0200146 opt = getopt32long(argv,
147 /* Must have -s or -t, exclusive */
148 "^alud:m:s:t:" "\0" "s:t:s--t:t--s", rtcwake_longopts,
Denys Vlasenko036585a2017-08-08 16:38:18 +0200149 &rtcname, &suspend, &opt_seconds, &opt_time);
Mike Frysinger6b160e42008-02-15 02:27:19 +0000150
151 /* this is the default
152 if (opt & RTCWAKE_OPT_AUTO)
153 utc = -1;
154 */
155 if (opt & (RTCWAKE_OPT_UTC | RTCWAKE_OPT_LOCAL))
156 utc = opt & RTCWAKE_OPT_UTC;
Denys Vlasenkoa4476eb2014-05-02 12:46:15 +0200157 if (opt & RTCWAKE_OPT_SECONDS) {
Mike Frysinger6b160e42008-02-15 02:27:19 +0000158 /* alarm time, seconds-to-sleep (relative) */
Denys Vlasenkoa4476eb2014-05-02 12:46:15 +0200159 seconds = xatou(opt_seconds);
160 } else {
161 /* RTCWAKE_OPT_TIME */
Mike Frysinger6b160e42008-02-15 02:27:19 +0000162 /* alarm time, time_t (absolute, seconds since 1/1 1970 UTC) */
Denys Vlasenkoa4476eb2014-05-02 12:46:15 +0200163 if (sizeof(alarm_time) <= sizeof(long))
164 alarm_time = xatol(opt_time);
165 else
166 alarm_time = xatoll(opt_time);
167 }
Mike Frysinger6b160e42008-02-15 02:27:19 +0000168
169 if (utc == -1)
170 utc = rtc_adjtime_is_utc();
171
172 /* the rtcname is relative to /dev */
173 xchdir("/dev");
174
Mike Frysinger6b160e42008-02-15 02:27:19 +0000175 /* this RTC must exist and (if we'll sleep) be wakeup-enabled */
Mike Frysinger977bc6a2008-02-15 07:19:03 +0000176 fd = rtc_xopen(&rtcname, O_RDONLY);
177
Denys Vlasenkoa4476eb2014-05-02 12:46:15 +0200178 if (strcmp(suspend, "on") != 0)
179 if (!may_wakeup(rtcname))
180 bb_error_msg_and_die("%s not enabled for wakeup events", rtcname);
Mike Frysinger6b160e42008-02-15 02:27:19 +0000181
182 /* relative or absolute alarm time, normalized to time_t */
Denis Vlasenko04158e02009-02-02 10:48:06 +0000183 sys_time = time(NULL);
Denys Vlasenko5e3b1402010-01-06 22:43:39 +0100184 {
Denys Vlasenkodc698bb2010-01-09 19:10:49 +0100185 struct tm tm_time;
186 rtc_read_tm(&tm_time, fd);
187 rtc_time = rtc_tm2time(&tm_time, utc);
Denys Vlasenko5e3b1402010-01-06 22:43:39 +0100188 }
189
Denys Vlasenkoa4476eb2014-05-02 12:46:15 +0200190 if (opt & RTCWAKE_OPT_TIME) {
191 /* Correct for RTC<->system clock difference */
192 alarm_time += rtc_time - sys_time;
193 if (alarm_time < rtc_time)
194 /*
195 * Compat message text.
196 * I'd say "RTC time is already ahead of ..." instead.
197 */
Mike Frysinger6b160e42008-02-15 02:27:19 +0000198 bb_error_msg_and_die("time doesn't go backward to %s", ctime(&alarm_time));
Mike Frysinger6b160e42008-02-15 02:27:19 +0000199 } else
200 alarm_time = rtc_time + seconds + 1;
Mike Frysinger6b160e42008-02-15 02:27:19 +0000201
Denys Vlasenkoa4476eb2014-05-02 12:46:15 +0200202 setup_alarm(fd, &alarm_time, rtc_time);
Mike Frysinger6b160e42008-02-15 02:27:19 +0000203 sync();
Denys Vlasenkoa4476eb2014-05-02 12:46:15 +0200204#if 0 /*debug*/
205 printf("sys_time: %s", ctime(&sys_time));
206 printf("rtc_time: %s", ctime(&rtc_time));
207#endif
Mike Frysinger6b160e42008-02-15 02:27:19 +0000208 printf("wakeup from \"%s\" at %s", suspend, ctime(&alarm_time));
Denys Vlasenko8131eea2009-11-02 14:19:51 +0100209 fflush_all();
Mike Frysinger6b160e42008-02-15 02:27:19 +0000210 usleep(10 * 1000);
211
Denys Vlasenkoa4476eb2014-05-02 12:46:15 +0200212 if (strcmp(suspend, "on") != 0)
Bernhard Reutner-Fischerae4342c2008-05-19 08:18:50 +0000213 xopen_xwrite_close(SYS_POWER_PATH, suspend);
Mike Frysinger6b160e42008-02-15 02:27:19 +0000214 else {
215 /* "fake" suspend ... we'll do the delay ourselves */
216 unsigned long data;
217
218 do {
219 ssize_t ret = safe_read(fd, &data, sizeof(data));
220 if (ret < 0) {
James Byrne69374872019-07-02 11:35:03 +0200221 bb_simple_perror_msg("rtc read");
Mike Frysinger6b160e42008-02-15 02:27:19 +0000222 break;
223 }
224 } while (!(data & RTC_AF));
225 }
226
227 xioctl(fd, RTC_AIE_OFF, 0);
228
229 if (ENABLE_FEATURE_CLEAN_UP)
230 close(fd);
231
232 return EXIT_SUCCESS;
233}