blob: 54fc70583498e4f966dc4c444518eb719a2b2f54
1 | /* |
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 | * |
6 | * Licensed under GPLv2, see file LICENSE in this source tree. |
7 | * |
8 | * 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 | */ |
25 | //config:config RTCWAKE |
26 | //config: bool "rtcwake" |
27 | //config: default y |
28 | //config: select PLATFORM_LINUX |
29 | //config: help |
30 | //config: Enter a system sleep state until specified wakeup time. |
31 | |
32 | //applet:IF_RTCWAKE(APPLET(rtcwake, BB_DIR_USR_SBIN, BB_SUID_DROP)) |
33 | |
34 | //kbuild:lib-$(CONFIG_RTCWAKE) += rtcwake.o |
35 | |
36 | //usage:#define rtcwake_trivial_usage |
37 | //usage: "[-a | -l | -u] [-d DEV] [-m MODE] [-s SEC | -t TIME]" |
38 | //usage:#define rtcwake_full_usage "\n\n" |
39 | //usage: "Enter a system sleep state until specified wakeup time\n" |
40 | //usage: IF_LONG_OPTS( |
41 | //usage: "\n -a,--auto Read clock mode from adjtime" |
42 | //usage: "\n -l,--local Clock is set to local time" |
43 | //usage: "\n -u,--utc Clock is set to UTC time" |
44 | //usage: "\n -d,--device=DEV Specify the RTC device" |
45 | //usage: "\n -m,--mode=MODE Set sleep state (default: standby)" |
46 | //usage: "\n -s,--seconds=SEC Set timeout in SEC seconds from now" |
47 | //usage: "\n -t,--time=TIME Set timeout to TIME seconds from epoch" |
48 | //usage: ) |
49 | //usage: IF_NOT_LONG_OPTS( |
50 | //usage: "\n -a Read clock mode from adjtime" |
51 | //usage: "\n -l Clock is set to local time" |
52 | //usage: "\n -u Clock is set to UTC time" |
53 | //usage: "\n -d DEV Specify the RTC device" |
54 | //usage: "\n -m MODE Set sleep state (default: standby)" |
55 | //usage: "\n -s SEC Set timeout in SEC seconds from now" |
56 | //usage: "\n -t TIME Set timeout to TIME seconds from epoch" |
57 | //usage: ) |
58 | |
59 | #include "libbb.h" |
60 | #include "rtc_.h" |
61 | |
62 | #define SYS_RTC_PATH "/sys/class/rtc/%s/device/power/wakeup" |
63 | #define SYS_POWER_PATH "/sys/power/state" |
64 | |
65 | static NOINLINE bool may_wakeup(const char *rtcname) |
66 | { |
67 | ssize_t ret; |
68 | char buf[128]; |
69 | |
70 | /* strip "/dev/" from the rtcname here */ |
71 | rtcname = skip_dev_pfx(rtcname); |
72 | |
73 | snprintf(buf, sizeof(buf), SYS_RTC_PATH, rtcname); |
74 | ret = open_read_close(buf, buf, sizeof(buf)); |
75 | if (ret < 0) |
76 | return false; |
77 | |
78 | /* wakeup events could be disabled or not supported */ |
79 | return is_prefixed_with(buf, "enabled\n") != NULL; |
80 | } |
81 | |
82 | static NOINLINE void setup_alarm(int fd, time_t *wakeup, time_t rtc_time) |
83 | { |
84 | struct tm *ptm; |
85 | struct linux_rtc_wkalrm wake; |
86 | |
87 | /* The wakeup time is in POSIX time (more or less UTC). |
88 | * Ideally RTCs use that same time; but PCs can't do that |
89 | * if they need to boot MS-Windows. Messy... |
90 | * |
91 | * When running in utc mode this process's timezone is UTC, |
92 | * so we'll pass a UTC date to the RTC. |
93 | * |
94 | * Else mode is local so the time given to the RTC |
95 | * will instead use the local time zone. |
96 | */ |
97 | ptm = localtime(wakeup); |
98 | |
99 | wake.time.tm_sec = ptm->tm_sec; |
100 | wake.time.tm_min = ptm->tm_min; |
101 | wake.time.tm_hour = ptm->tm_hour; |
102 | wake.time.tm_mday = ptm->tm_mday; |
103 | wake.time.tm_mon = ptm->tm_mon; |
104 | wake.time.tm_year = ptm->tm_year; |
105 | /* wday, yday, and isdst fields are unused by Linux */ |
106 | wake.time.tm_wday = -1; |
107 | wake.time.tm_yday = -1; |
108 | wake.time.tm_isdst = -1; |
109 | |
110 | /* many rtc alarms only support up to 24 hours from 'now', |
111 | * so use the "more than 24 hours" request only if we must |
112 | */ |
113 | if ((rtc_time + (24 * 60 * 60)) > *wakeup) { |
114 | xioctl(fd, RTC_ALM_SET, &wake.time); |
115 | xioctl(fd, RTC_AIE_ON, 0); |
116 | } else { |
117 | /* avoid an extra AIE_ON call */ |
118 | wake.enabled = 1; |
119 | xioctl(fd, RTC_WKALM_SET, &wake); |
120 | } |
121 | } |
122 | |
123 | #define RTCWAKE_OPT_AUTO 0x01 |
124 | #define RTCWAKE_OPT_LOCAL 0x02 |
125 | #define RTCWAKE_OPT_UTC 0x04 |
126 | #define RTCWAKE_OPT_DEVICE 0x08 |
127 | #define RTCWAKE_OPT_SUSPEND_MODE 0x10 |
128 | #define RTCWAKE_OPT_SECONDS 0x20 |
129 | #define RTCWAKE_OPT_TIME 0x40 |
130 | |
131 | int rtcwake_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
132 | int rtcwake_main(int argc UNUSED_PARAM, char **argv) |
133 | { |
134 | unsigned opt; |
135 | const char *rtcname = NULL; |
136 | const char *suspend = "standby"; |
137 | const char *opt_seconds; |
138 | const char *opt_time; |
139 | |
140 | time_t rtc_time; |
141 | time_t sys_time; |
142 | time_t alarm_time = alarm_time; |
143 | unsigned seconds = seconds; /* for compiler */ |
144 | int utc = -1; |
145 | int fd; |
146 | |
147 | #if ENABLE_LONG_OPTS |
148 | static const char rtcwake_longopts[] ALIGN1 = |
149 | "auto\0" No_argument "a" |
150 | "local\0" No_argument "l" |
151 | "utc\0" No_argument "u" |
152 | "device\0" Required_argument "d" |
153 | "mode\0" Required_argument "m" |
154 | "seconds\0" Required_argument "s" |
155 | "time\0" Required_argument "t" |
156 | ; |
157 | applet_long_options = rtcwake_longopts; |
158 | #endif |
159 | /* Must have -s or -t, exclusive */ |
160 | opt_complementary = "s:t:s--t:t--s"; |
161 | opt = getopt32(argv, "alud:m:s:t:", &rtcname, &suspend, &opt_seconds, &opt_time); |
162 | |
163 | /* this is the default |
164 | if (opt & RTCWAKE_OPT_AUTO) |
165 | utc = -1; |
166 | */ |
167 | if (opt & (RTCWAKE_OPT_UTC | RTCWAKE_OPT_LOCAL)) |
168 | utc = opt & RTCWAKE_OPT_UTC; |
169 | if (opt & RTCWAKE_OPT_SECONDS) { |
170 | /* alarm time, seconds-to-sleep (relative) */ |
171 | seconds = xatou(opt_seconds); |
172 | } else { |
173 | /* RTCWAKE_OPT_TIME */ |
174 | /* alarm time, time_t (absolute, seconds since 1/1 1970 UTC) */ |
175 | if (sizeof(alarm_time) <= sizeof(long)) |
176 | alarm_time = xatol(opt_time); |
177 | else |
178 | alarm_time = xatoll(opt_time); |
179 | } |
180 | |
181 | if (utc == -1) |
182 | utc = rtc_adjtime_is_utc(); |
183 | |
184 | /* the rtcname is relative to /dev */ |
185 | xchdir("/dev"); |
186 | |
187 | /* this RTC must exist and (if we'll sleep) be wakeup-enabled */ |
188 | fd = rtc_xopen(&rtcname, O_RDONLY); |
189 | |
190 | if (strcmp(suspend, "on") != 0) |
191 | if (!may_wakeup(rtcname)) |
192 | bb_error_msg_and_die("%s not enabled for wakeup events", rtcname); |
193 | |
194 | /* relative or absolute alarm time, normalized to time_t */ |
195 | sys_time = time(NULL); |
196 | { |
197 | struct tm tm_time; |
198 | rtc_read_tm(&tm_time, fd); |
199 | rtc_time = rtc_tm2time(&tm_time, utc); |
200 | } |
201 | |
202 | if (opt & RTCWAKE_OPT_TIME) { |
203 | /* Correct for RTC<->system clock difference */ |
204 | alarm_time += rtc_time - sys_time; |
205 | if (alarm_time < rtc_time) |
206 | /* |
207 | * Compat message text. |
208 | * I'd say "RTC time is already ahead of ..." instead. |
209 | */ |
210 | bb_error_msg_and_die("time doesn't go backward to %s", ctime(&alarm_time)); |
211 | } else |
212 | alarm_time = rtc_time + seconds + 1; |
213 | |
214 | setup_alarm(fd, &alarm_time, rtc_time); |
215 | sync(); |
216 | #if 0 /*debug*/ |
217 | printf("sys_time: %s", ctime(&sys_time)); |
218 | printf("rtc_time: %s", ctime(&rtc_time)); |
219 | #endif |
220 | printf("wakeup from \"%s\" at %s", suspend, ctime(&alarm_time)); |
221 | fflush_all(); |
222 | usleep(10 * 1000); |
223 | |
224 | if (strcmp(suspend, "on") != 0) |
225 | xopen_xwrite_close(SYS_POWER_PATH, suspend); |
226 | else { |
227 | /* "fake" suspend ... we'll do the delay ourselves */ |
228 | unsigned long data; |
229 | |
230 | do { |
231 | ssize_t ret = safe_read(fd, &data, sizeof(data)); |
232 | if (ret < 0) { |
233 | bb_perror_msg("rtc read"); |
234 | break; |
235 | } |
236 | } while (!(data & RTC_AF)); |
237 | } |
238 | |
239 | xioctl(fd, RTC_AIE_OFF, 0); |
240 | |
241 | if (ENABLE_FEATURE_CLEAN_UP) |
242 | close(fd); |
243 | |
244 | return EXIT_SUCCESS; |
245 | } |
246 |