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authorMike Frysinger <vapier@gentoo.org>2008-02-15 02:27:19 +0000
committerMike Frysinger <vapier@gentoo.org>2008-02-15 02:27:19 +0000
commit6b160e490d4d77596c1603d34d0a1ca0579a82da (patch)
tree653ab55714a0373751b619144e56b5ea163938f2 /util-linux/rtcwake.c
parentbe7d2a8ded621a6d62f8caa76f7c51185b166ab1 (diff)
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split some rtc funcs out of hwclock and into an rtc header/lib so that the new rtcwake applet as well as hwclock can utilize the same code
Diffstat (limited to 'util-linux/rtcwake.c')
-rw-r--r--util-linux/rtcwake.c209
1 files changed, 209 insertions, 0 deletions
diff --git a/util-linux/rtcwake.c b/util-linux/rtcwake.c
new file mode 100644
index 000000000..718f43d45
--- /dev/null
+++ b/util-linux/rtcwake.c
@@ -0,0 +1,209 @@
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 * This uses cross-platform Linux interfaces to enter a system sleep state,
7 * and leave it no later than a specified time. It uses any RTC framework
8 * driver that supports standard driver model wakeup flags.
9 *
10 * This is normally used like the old "apmsleep" utility, to wake from a
11 * suspend state like ACPI S1 (standby) or S3 (suspend-to-RAM). Most
12 * platforms can implement those without analogues of BIOS, APM, or ACPI.
13 *
14 * On some systems, this can also be used like "nvram-wakeup", waking
15 * from states like ACPI S4 (suspend to disk). Not all systems have
16 * persistent media that are appropriate for such suspend modes.
17 *
18 * The best way to set the system's RTC is so that it holds the current
19 * time in UTC. Use the "-l" flag to tell this program that the system
20 * RTC uses a local timezone instead (maybe you dual-boot MS-Windows).
21 * That flag should not be needed on systems with adjtime support.
22 */
23
24#include "libbb.h"
25#include "rtc_.h"
26
27#define SYS_RTC_PATH "/sys/class/rtc/%s/device/power/wakeup"
28#define SYS_POWER_PATH "/sys/power/state"
29#define DEFAULT_MODE "suspend"
30
31static time_t rtc_time;
32
33static int may_wakeup(const char *rtcname)
34{
35 ssize_t ret;
36 char buf[128];
37
38 /* strip the '/dev/' from the rtcname here */
39 if (!strncmp(rtcname, "/dev/", 5))
40 rtcname += 5;
41
42 snprintf(buf, sizeof(buf), SYS_RTC_PATH, rtcname);
43 ret = open_read_close(buf, buf, sizeof(buf));
44 if (ret < 0)
45 return 0;
46
47 /* wakeup events could be disabled or not supported */
48 return strcmp(buf, "enabled\n") == 0;
49}
50
51static void setup_alarm(int fd, time_t *wakeup)
52{
53 struct tm *tm;
54 struct linux_rtc_wkalrm wake;
55
56 /* The wakeup time is in POSIX time (more or less UTC).
57 * Ideally RTCs use that same time; but PCs can't do that
58 * if they need to boot MS-Windows. Messy...
59 *
60 * When running in utc mode this process's timezone is UTC,
61 * so we'll pass a UTC date to the RTC.
62 *
63 * Else mode is local so the time given to the RTC
64 * will instead use the local time zone.
65 */
66 tm = localtime(wakeup);
67
68 wake.time.tm_sec = tm->tm_sec;
69 wake.time.tm_min = tm->tm_min;
70 wake.time.tm_hour = tm->tm_hour;
71 wake.time.tm_mday = tm->tm_mday;
72 wake.time.tm_mon = tm->tm_mon;
73 wake.time.tm_year = tm->tm_year;
74 /* wday, yday, and isdst fields are unused by Linux */
75 wake.time.tm_wday = -1;
76 wake.time.tm_yday = -1;
77 wake.time.tm_isdst = -1;
78
79 /* many rtc alarms only support up to 24 hours from 'now',
80 * so use the "more than 24 hours" request only if we must
81 */
82 if ((rtc_time + (24 * 60 * 60)) > *wakeup) {
83 xioctl(fd, RTC_ALM_SET, &wake.time);
84 xioctl(fd, RTC_AIE_ON, 0);
85 } else {
86 /* avoid an extra AIE_ON call */
87 wake.enabled = 1;
88 xioctl(fd, RTC_WKALM_SET, &wake);
89 }
90}
91
92static void suspend_system(const char *suspend)
93{
94 FILE *f = xfopen(SYS_POWER_PATH, "w");
95 fprintf(f, "%s\n", suspend);
96 fflush(f);
97 /* this executes after wake from suspend */
98 fclose(f);
99}
100
101#define RTCWAKE_OPT_AUTO 0x01
102#define RTCWAKE_OPT_LOCAL 0x02
103#define RTCWAKE_OPT_UTC 0x04
104#define RTCWAKE_OPT_DEVICE 0x08
105#define RTCWAKE_OPT_SUSPEND_MODE 0x10
106#define RTCWAKE_OPT_SECONDS 0x20
107#define RTCWAKE_OPT_TIME 0x40
108
109int rtcwake_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
110int rtcwake_main(int argc, char **argv)
111{
112 unsigned opt;
113 const char *rtcname = NULL;
114 const char *suspend;
115 const char *opt_seconds;
116 const char *opt_time;
117
118 time_t sys_time;
119 time_t alarm_time = 0;
120 unsigned seconds = 0;
121 int utc = -1;
122 int fd;
123
124#if ENABLE_GETOPT_LONG
125 static const char rtcwake_longopts[] ALIGN1 =
126 "auto\0" No_argument "a"
127 "local\0" No_argument "l"
128 "utc\0" No_argument "u"
129 "device\0" Required_argument "d"
130 "mode\0" Required_argument "m"
131 "seconds\0" Required_argument "s"
132 "time\0" Required_argument "t"
133 ;
134 applet_long_options = rtcwake_longopts;
135 }
136#endif
137 opt = getopt32(argv, "alud:m:s:t:", &rtcname, &suspend, &opt_seconds, &opt_time);
138
139 /* this is the default
140 if (opt & RTCWAKE_OPT_AUTO)
141 utc = -1;
142 */
143 if (opt & (RTCWAKE_OPT_UTC | RTCWAKE_OPT_LOCAL))
144 utc = opt & RTCWAKE_OPT_UTC;
145 if (!(opt & RTCWAKE_OPT_SUSPEND_MODE))
146 suspend = DEFAULT_MODE;
147 if (opt & RTCWAKE_OPT_SECONDS)
148 /* alarm time, seconds-to-sleep (relative) */
149 seconds = xatoi(opt_seconds);
150 if (opt & RTCWAKE_OPT_TIME)
151 /* alarm time, time_t (absolute, seconds since 1/1 1970 UTC) */
152 alarm_time = xatoi(opt_time);
153
154 if (!alarm_time && !seconds)
155 bb_error_msg_and_die("must provide wake time");
156
157 if (utc == -1)
158 utc = rtc_adjtime_is_utc();
159
160 /* the rtcname is relative to /dev */
161 xchdir("/dev");
162
163 if (strcmp(suspend, "on") != 0 && !may_wakeup(rtcname))
164 bb_error_msg_and_die("%s not enabled for wakeup events", rtcname);
165
166 /* this RTC must exist and (if we'll sleep) be wakeup-enabled */
167 fd = rtc_xopen(rtcname, O_RDONLY);
168
169 /* relative or absolute alarm time, normalized to time_t */
170 sys_time = time(0);
171 if (sys_time == (time_t)-1)
172 bb_perror_msg_and_die("read system time");
173 rtc_time = rtc_read_time(fd, utc);
174
175 if (alarm_time) {
176 if (alarm_time < sys_time)
177 bb_error_msg_and_die("time doesn't go backward to %s", ctime(&alarm_time));
178 alarm_time += sys_time - rtc_time;
179 } else
180 alarm_time = rtc_time + seconds + 1;
181 setup_alarm(fd, &alarm_time);
182
183 sync();
184 printf("wakeup from \"%s\" at %s", suspend, ctime(&alarm_time));
185 fflush(stdout);
186 usleep(10 * 1000);
187
188 if (!strcmp(suspend, "on"))
189 suspend_system(suspend);
190 else {
191 /* "fake" suspend ... we'll do the delay ourselves */
192 unsigned long data;
193
194 do {
195 ssize_t ret = safe_read(fd, &data, sizeof(data));
196 if (ret < 0) {
197 bb_perror_msg("rtc read");
198 break;
199 }
200 } while (!(data & RTC_AF));
201 }
202
203 xioctl(fd, RTC_AIE_OFF, 0);
204
205 if (ENABLE_FEATURE_CLEAN_UP)
206 close(fd);
207
208 return EXIT_SUCCESS;
209}
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