1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
|
/*
* rtcwake -- enter a system sleep state until specified wakeup time.
*
* This version was taken from util-linux and scrubbed down for busybox.
*
* Licensed under GPLv2, see file LICENSE in this source tree.
*
* This uses cross-platform Linux interfaces to enter a system sleep state,
* and leave it no later than a specified time. It uses any RTC framework
* driver that supports standard driver model wakeup flags.
*
* This is normally used like the old "apmsleep" utility, to wake from a
* suspend state like ACPI S1 (standby) or S3 (suspend-to-RAM). Most
* platforms can implement those without analogues of BIOS, APM, or ACPI.
*
* On some systems, this can also be used like "nvram-wakeup", waking
* from states like ACPI S4 (suspend to disk). Not all systems have
* persistent media that are appropriate for such suspend modes.
*
* The best way to set the system's RTC is so that it holds the current
* time in UTC. Use the "-l" flag to tell this program that the system
* RTC uses a local timezone instead (maybe you dual-boot MS-Windows).
* That flag should not be needed on systems with adjtime support.
*/
//config:config RTCWAKE
//config: bool "rtcwake (6.8 kb)"
//config: default y
//config: help
//config: Enter a system sleep state until specified wakeup time.
//applet:IF_RTCWAKE(APPLET(rtcwake, BB_DIR_USR_SBIN, BB_SUID_DROP))
//kbuild:lib-$(CONFIG_RTCWAKE) += rtcwake.o
//usage:#define rtcwake_trivial_usage
//usage: "[-a | -l | -u] [-d DEV] [-m MODE] [-s SEC | -t TIME]"
//usage:#define rtcwake_full_usage "\n\n"
//usage: "Enter a system sleep state until specified wakeup time\n"
//usage: IF_LONG_OPTS(
//usage: "\n -a,--auto Read clock mode from adjtime"
//usage: "\n -l,--local Clock is set to local time"
//usage: "\n -u,--utc Clock is set to UTC time"
//usage: "\n -d,--device DEV Specify the RTC device"
//usage: "\n -m,--mode MODE Set sleep state (default: standby)"
//usage: "\n -s,--seconds SEC Set timeout in SEC seconds from now"
//usage: "\n -t,--time TIME Set timeout to TIME seconds from epoch"
//usage: )
//usage: IF_NOT_LONG_OPTS(
//usage: "\n -a Read clock mode from adjtime"
//usage: "\n -l Clock is set to local time"
//usage: "\n -u Clock is set to UTC time"
//usage: "\n -d DEV Specify the RTC device"
//usage: "\n -m MODE Set sleep state (default: standby)"
//usage: "\n -s SEC Set timeout in SEC seconds from now"
//usage: "\n -t TIME Set timeout to TIME seconds from epoch"
//usage: )
#include "libbb.h"
#include "rtc_.h"
#define SYS_RTC_PATH "/sys/class/rtc/%s/device/power/wakeup"
#define SYS_POWER_PATH "/sys/power/state"
static NOINLINE bool may_wakeup(const char *rtcname)
{
ssize_t ret;
char buf[128];
/* strip "/dev/" from the rtcname here */
rtcname = skip_dev_pfx(rtcname);
snprintf(buf, sizeof(buf), SYS_RTC_PATH, rtcname);
ret = open_read_close(buf, buf, sizeof(buf));
if (ret < 0)
return false;
/* wakeup events could be disabled or not supported */
return is_prefixed_with(buf, "enabled\n") != NULL;
}
static NOINLINE void setup_alarm(int fd, time_t *wakeup, time_t rtc_time)
{
struct tm *ptm;
struct linux_rtc_wkalrm wake;
/* The wakeup time is in POSIX time (more or less UTC).
* Ideally RTCs use that same time; but PCs can't do that
* if they need to boot MS-Windows. Messy...
*
* When running in utc mode this process's timezone is UTC,
* so we'll pass a UTC date to the RTC.
*
* Else mode is local so the time given to the RTC
* will instead use the local time zone.
*/
ptm = localtime(wakeup);
wake.time.tm_sec = ptm->tm_sec;
wake.time.tm_min = ptm->tm_min;
wake.time.tm_hour = ptm->tm_hour;
wake.time.tm_mday = ptm->tm_mday;
wake.time.tm_mon = ptm->tm_mon;
wake.time.tm_year = ptm->tm_year;
/* wday, yday, and isdst fields are unused by Linux */
wake.time.tm_wday = -1;
wake.time.tm_yday = -1;
wake.time.tm_isdst = -1;
/* many rtc alarms only support up to 24 hours from 'now',
* so use the "more than 24 hours" request only if we must
*/
if ((rtc_time + (24 * 60 * 60)) > *wakeup) {
xioctl(fd, RTC_ALM_SET, &wake.time);
xioctl(fd, RTC_AIE_ON, 0);
} else {
/* avoid an extra AIE_ON call */
wake.enabled = 1;
xioctl(fd, RTC_WKALM_SET, &wake);
}
}
#define RTCWAKE_OPT_AUTO 0x01
#define RTCWAKE_OPT_LOCAL 0x02
#define RTCWAKE_OPT_UTC 0x04
#define RTCWAKE_OPT_DEVICE 0x08
#define RTCWAKE_OPT_SUSPEND_MODE 0x10
#define RTCWAKE_OPT_SECONDS 0x20
#define RTCWAKE_OPT_TIME 0x40
int rtcwake_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int rtcwake_main(int argc UNUSED_PARAM, char **argv)
{
unsigned opt;
const char *rtcname = NULL;
const char *suspend = "standby";
const char *opt_seconds;
const char *opt_time;
time_t rtc_time;
time_t sys_time;
time_t alarm_time = alarm_time;
unsigned seconds = seconds; /* for compiler */
int utc = -1;
int fd;
#if ENABLE_LONG_OPTS
static const char rtcwake_longopts[] ALIGN1 =
"auto\0" No_argument "a"
"local\0" No_argument "l"
"utc\0" No_argument "u"
"device\0" Required_argument "d"
"mode\0" Required_argument "m"
"seconds\0" Required_argument "s"
"time\0" Required_argument "t"
;
#endif
opt = getopt32long(argv,
/* Must have -s or -t, exclusive */
"^alud:m:s:t:" "\0" "s:t:s--t:t--s", rtcwake_longopts,
&rtcname, &suspend, &opt_seconds, &opt_time);
/* this is the default
if (opt & RTCWAKE_OPT_AUTO)
utc = -1;
*/
if (opt & (RTCWAKE_OPT_UTC | RTCWAKE_OPT_LOCAL))
utc = opt & RTCWAKE_OPT_UTC;
if (opt & RTCWAKE_OPT_SECONDS) {
/* alarm time, seconds-to-sleep (relative) */
seconds = xatou(opt_seconds);
} else {
/* RTCWAKE_OPT_TIME */
/* alarm time, time_t (absolute, seconds since 1/1 1970 UTC) */
if (sizeof(alarm_time) <= sizeof(long))
alarm_time = xatol(opt_time);
else
alarm_time = xatoll(opt_time);
}
if (utc == -1)
utc = rtc_adjtime_is_utc();
/* the rtcname is relative to /dev */
xchdir("/dev");
/* this RTC must exist and (if we'll sleep) be wakeup-enabled */
fd = rtc_xopen(&rtcname, O_RDONLY);
if (strcmp(suspend, "on") != 0)
if (!may_wakeup(rtcname))
bb_error_msg_and_die("%s not enabled for wakeup events", rtcname);
/* relative or absolute alarm time, normalized to time_t */
sys_time = time(NULL);
{
struct tm tm_time;
rtc_read_tm(&tm_time, fd);
rtc_time = rtc_tm2time(&tm_time, utc);
}
if (opt & RTCWAKE_OPT_TIME) {
/* Correct for RTC<->system clock difference */
alarm_time += rtc_time - sys_time;
if (alarm_time < rtc_time)
/*
* Compat message text.
* I'd say "RTC time is already ahead of ..." instead.
*/
bb_error_msg_and_die("time doesn't go backward to %s", ctime(&alarm_time));
} else
alarm_time = rtc_time + seconds + 1;
setup_alarm(fd, &alarm_time, rtc_time);
sync();
#if 0 /*debug*/
printf("sys_time: %s", ctime(&sys_time));
printf("rtc_time: %s", ctime(&rtc_time));
#endif
printf("wakeup from \"%s\" at %s", suspend, ctime(&alarm_time));
fflush_all();
usleep(10 * 1000);
if (strcmp(suspend, "on") != 0)
xopen_xwrite_close(SYS_POWER_PATH, suspend);
else {
/* "fake" suspend ... we'll do the delay ourselves */
unsigned long data;
do {
ssize_t ret = safe_read(fd, &data, sizeof(data));
if (ret < 0) {
bb_simple_perror_msg("rtc read");
break;
}
} while (!(data & RTC_AF));
}
xioctl(fd, RTC_AIE_OFF, 0);
if (ENABLE_FEATURE_CLEAN_UP)
close(fd);
return EXIT_SUCCESS;
}
|
