LXR toybox/toys/other/rtcwake.c

   1/* rtcwake.c - enter sleep state until given time.
   2 *
   3 * Copyright 2020 The Android Open Source Project
   4
   5USE_RTCWAKE(NEWTOY(rtcwake, "(list-modes);(auto)a(device)d:(local)l(mode)m:(seconds)s#(time)t#(utc)u(verbose)v[!alu]", TOYFLAG_USR|TOYFLAG_BIN))
   6
   7config RTCWAKE
   8  bool "rtcwake"
   9  default y
  10  help
  11    usage: rtcwake [-aluv] [-d FILE] [-m MODE] [-s SECS] [-t UNIX]
  12
  13    Enter the given sleep state until the given time.
  14
  15    -a  RTC uses time specified in /etc/adjtime
  16    -d FILE     Device to use (default /dev/rtc)
  17    -l  RTC uses local time
  18    -m  Mode (--list-modes to see those supported by your kernel):
  19          standby  S1: default              mem     S3: suspend to RAM
  20          disk     S4: suspend to disk      off     S5: power off
  21          disable  Cancel current alarm     freeze  stop processes/processors
  22          no       just set wakeup time     on      just poll RTC for alarm
  23          show     just show current alarm
  24    -s SECS     Wake SECS seconds from now
  25    -t UNIX     Wake UNIX seconds from epoch
  26    -u  RTC uses UTC
  27    -v  Verbose
  28*/
  29
  30#define FOR_rtcwake
  31#include "toys.h"
  32#include <linux/rtc.h>
  33
  34GLOBALS(
  35  long t, s;
  36  char *m, *d;
  37)
  38
  39void rtcwake_main(void)
  40{
  41  struct rtc_wkalrm *alarm = (void *)(toybuf+2048);
  42  struct tm rtc_tm;
  43  time_t now, rtc_now, then;
  44  int fd, utc;
  45
  46  if (FLAG(list_modes)) {
  47    printf("off no on disable show %s",
  48      xreadfile("/sys/power/state", toybuf, 2048));
  49    return;
  50  }
  51
  52  // util-linux defaults to "suspend", even though I don't have anything that
  53  // supports that (testing everything from a ~2010 laptop to a 2019 desktop).
  54  if (!TT.m) TT.m = "suspend";
  55
  56  if (FLAG(u)) utc = 1;
  57  else if (FLAG(l)) utc = 0;
  58  else utc = !readfile("/etc/adjtime", toybuf, 2048) || !!strstr(toybuf, "UTC");
  59  if (FLAG(v)) xprintf("RTC time: %s\n", utc ? "UTC" : "local");
  60
  61  if (!TT.d) TT.d = "/dev/rtc0";
  62  if (FLAG(v)) xprintf("Device: %s\n", TT.d);
  63  fd = xopen(TT.d, O_RDWR);
  64
  65  now = time(0);
  66  xioctl(fd, RTC_RD_TIME, &rtc_tm);
  67  rtc_now = xmktime(&rtc_tm, utc);
  68  if (FLAG(v)) {
  69    xprintf("System time:\t%lld / %s", (long long)now, ctime(&now));
  70    xprintf("RTC time:\t%lld / %s", (long long)rtc_now, ctime(&rtc_now));
  71  }
  72
  73  if (!strcmp(TT.m, "show")) { // Don't suspend, just show current alarm.
  74    xioctl(fd, RTC_WKALM_RD, alarm);
  75    if (!alarm->enabled) xputs("alarm: off");
  76    else {
  77      if ((then = mktime((void *)&alarm->time)) < 0) perror_exit("mktime");
  78      xprintf("alarm: on %s", ctime(&then));
  79    }
  80    return;
  81  } else if (!strcmp(TT.m, "disable")) { // Cancel current alarm.
  82    xioctl(fd, RTC_WKALM_RD, alarm);
  83    alarm->enabled = 0;
  84    xioctl(fd, RTC_WKALM_SET, alarm);
  85    return;
  86  }
  87
  88  if (FLAG(s)) then = rtc_now + TT.s + 1; // strace shows util-linux adds 1.
  89  else if (FLAG(t)) {
  90    then = TT.t + (rtc_now - now);
  91    if (then<=rtc_now) error_exit("rtc %lld >= %ld", (long long)rtc_now, TT.t);
  92  } else help_exit("-m %s needs -s or -t", TT.m);
  93  if (FLAG(v)) xprintf("Wake time:\t%lld / %s", (long long)then, ctime(&then));
  94
  95  if (!(utc ? gmtime_r : localtime_r)(&then, (void *)&alarm->time))
  96    error_exit("%s failed", utc ? "gmtime_r" : "localtime_r");
  97
  98  alarm->enabled = 1;
  99  xioctl(fd, RTC_WKALM_SET, alarm);
 100  sync();
 101
 102  xprintf("wakeup using \"%s\" from %s at %s", TT.m, TT.d, ctime(&then));
 103  msleep(10);
 104
 105  if (!strcmp(TT.m, "no")); // Don't suspend, just set wakeup time.
 106  else if (!strcmp(TT.m, "on")) { // Don't suspend, poll RTC for alarm.
 107    unsigned long data = 0;
 108
 109    if (FLAG(v)) xputs("Reading RTC...");
 110    while (!(data & RTC_AF)) {
 111      if (read(fd, &data, sizeof(data)) != sizeof(data)) perror_exit("read");
 112      if (FLAG(v)) xprintf("... %s: %lx\n", TT.d, data);
 113    }
 114  } else if (!strcmp(TT.m, "off")) xexec((char *[]){"poweroff", 0});
 115  // Everything else lands here for one final step. The write will fail with
 116  // EINVAL if the mode is not supported.
 117  else xwrite(xopen("/sys/power/state", O_WRONLY), TT.m, strlen(TT.m));
 118}
 119