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-rw-r--r--sys-utils/rtcwake.c488
1 files changed, 488 insertions, 0 deletions
diff --git a/sys-utils/rtcwake.c b/sys-utils/rtcwake.c
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--- /dev/null
+++ b/sys-utils/rtcwake.c
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+/*
+ * rtcwake -- enter a system sleep state until specified wakeup time.
+ *
+ * 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.
+ */
+
+#include <stdio.h>
+#include <getopt.h>
+#include <fcntl.h>
+#include <libgen.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#include <time.h>
+
+#include <sys/ioctl.h>
+#include <sys/time.h>
+#include <sys/types.h>
+
+#include <linux/rtc.h>
+
+#include "nls.h"
+#include "usleep.h"
+
+/* constants from legacy PC/AT hardware */
+#define RTC_PF 0x40
+#define RTC_AF 0x20
+#define RTC_UF 0x10
+
+#define MAX_LINE 1024
+
+static char *progname;
+
+#define VERSION_STRING "rtcwake from " PACKAGE_STRING
+#define RTC_PATH "/sys/class/rtc/%s/device/power/wakeup"
+#define SYS_POWER_STATE_PATH "/sys/power/state"
+#define ADJTIME_PATH "/etc/adjtime"
+#define DEFAULT_DEVICE "/dev/rtc0"
+#define DEFAULT_MODE "standby"
+
+enum ClockMode {
+ CM_AUTO,
+ CM_UTC,
+ CM_LOCAL
+};
+
+static unsigned verbose;
+enum ClockMode clock_mode = CM_AUTO;
+
+static struct option long_options[] = {
+ {"auto", no_argument, 0, 'a'},
+ {"local", no_argument, 0, 'l'},
+ {"utc", no_argument, 0, 'u'},
+ {"verbose", no_argument, 0, 'v'},
+ {"version", no_argument, 0, 'V'},
+ {"help", no_argument, 0, 'h'},
+ {"mode", required_argument, 0, 'm'},
+ {"device", required_argument, 0, 'd'},
+ {"seconds", required_argument, 0, 's'},
+ {"time", required_argument, 0, 't'},
+ {0, 0, 0, 0 }
+};
+
+static void usage(int retval)
+{
+ printf(_("usage: %s [options]\n"
+ " -d | --device <device> select rtc device (rtc0|rtc1|...)\n"
+ " -l | --local RTC uses local timezone\n"
+ " -m | --mode standby|mem|... sleep mode\n"
+ " -s | --seconds <seconds> seconds to sleep\n"
+ " -t | --time <time_t> time to wake\n"
+ " -u | --utc RTC uses UTC\n"
+ " -v | --verbose verbose messages\n"
+ " -V | --version show version\n"),
+ progname);
+ exit(retval);
+}
+
+static int is_wakeup_enabled(const char *devname)
+{
+ char buf[128], *s;
+ FILE *f;
+
+ /* strip the '/dev/' from the devname here */
+ snprintf(buf, sizeof buf, RTC_PATH, devname + strlen("/dev/"));
+ f = fopen(buf, "r");
+ if (!f) {
+ perror(buf);
+ return 0;
+ }
+ s = fgets(buf, sizeof buf, f);
+ fclose(f);
+ if (!s)
+ return 0;
+
+ s = strchr(buf, '\n');
+ if (!s)
+ return 0;
+ *s = 0;
+
+ /* wakeup events could be disabled or not supported */
+ return strcmp(buf, "enabled") == 0;
+}
+
+/* all times should be in UTC */
+static time_t sys_time;
+static time_t rtc_time;
+
+static int get_basetimes(int fd)
+{
+ struct tm tm;
+ struct rtc_time rtc;
+
+ /* this process works in RTC time, except when working
+ * with the system clock (which always uses UTC).
+ */
+ if (clock_mode == CM_UTC)
+ setenv("TZ", "UTC", 1);
+ tzset();
+
+ /* read rtc and system clocks "at the same time", or as
+ * precisely (+/- a second) as we can read them.
+ */
+ if (ioctl(fd, RTC_RD_TIME, &rtc) < 0) {
+ perror(_("read rtc time"));
+ return -1;
+ }
+ sys_time = time(0);
+ if (sys_time == (time_t)-1) {
+ perror(_("read system time"));
+ return -1;
+ }
+
+ /* convert rtc_time to normal arithmetic-friendly form,
+ * updating tm.tm_wday as used by asctime().
+ */
+ memset(&tm, 0, sizeof tm);
+ tm.tm_sec = rtc.tm_sec;
+ tm.tm_min = rtc.tm_min;
+ tm.tm_hour = rtc.tm_hour;
+ tm.tm_mday = rtc.tm_mday;
+ tm.tm_mon = rtc.tm_mon;
+ tm.tm_year = rtc.tm_year;
+ tm.tm_isdst = rtc.tm_isdst; /* stays unspecified? */
+ rtc_time = mktime(&tm);
+
+ if (rtc_time == (time_t)-1) {
+ perror(_("convert rtc time"));
+ return -1;
+ }
+
+ if (verbose) {
+ /* Unless the system uses UTC, either delta or tzone
+ * reflects a seconds offset from UTC. The value can
+ * help sort out problems like bugs in your C library.
+ */
+ printf("\tdelta = %ld\n", sys_time - rtc_time);
+ printf("\ttzone = %ld\n", timezone);
+
+ printf("\ttzname = %s\n", tzname[daylight]);
+ gmtime_r(&rtc_time, &tm);
+ printf("\tsystime = %ld, (UTC) %s",
+ (long) sys_time, asctime(gmtime(&sys_time)));
+ printf("\trtctime = %ld, (UTC) %s",
+ (long) rtc_time, asctime(&tm));
+ }
+
+ return 0;
+}
+
+static int setup_alarm(int fd, time_t *wakeup)
+{
+ struct tm *tm;
+ struct 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 clock_mode == CM_UTC this process's timezone is UTC,
+ * so we'll pass a UTC date to the RTC.
+ *
+ * Else clock_mode == CM_LOCAL so the time given to the RTC
+ * will instead use the local time zone.
+ */
+ tm = localtime(wakeup);
+
+ wake.time.tm_sec = tm->tm_sec;
+ wake.time.tm_min = tm->tm_min;
+ wake.time.tm_hour = tm->tm_hour;
+ wake.time.tm_mday = tm->tm_mday;
+ wake.time.tm_mon = tm->tm_mon;
+ wake.time.tm_year = tm->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;
+
+ wake.enabled = 1;
+ /* First try the preferred RTC_WKALM_SET */
+ if (ioctl(fd, RTC_WKALM_SET, &wake) < 0) {
+ wake.enabled = 0;
+ /* Fall back on the non-preferred way of setting wakeups; only
+ * works for alarms < 24 hours from now */
+ if ((rtc_time + (24 * 60 * 60)) > *wakeup) {
+ if (ioctl(fd, RTC_ALM_SET, &wake.time) < 0) {
+ perror(_("set rtc alarm"));
+ return -1;
+ }
+ if (ioctl(fd, RTC_AIE_ON, 0) < 0) {
+ perror(_("enable rtc alarm"));
+ return -1;
+ }
+ } else {
+ perror(_("set rtc wake alarm"));
+ return -1;
+ }
+ }
+
+ return 0;
+}
+
+static void suspend_system(const char *suspend)
+{
+ FILE *f = fopen(SYS_POWER_STATE_PATH, "w");
+
+ if (!f) {
+ perror(SYS_POWER_STATE_PATH);
+ return;
+ }
+
+ fprintf(f, "%s\n", suspend);
+ fflush(f);
+
+ /* this executes after wake from suspend */
+ fclose(f);
+}
+
+
+static int read_clock_mode(void)
+{
+ FILE *fp;
+ char linebuf[MAX_LINE];
+
+ fp = fopen(ADJTIME_PATH, "r");
+ if (!fp)
+ return -1;
+
+ /* skip first line */
+ if (!fgets(linebuf, MAX_LINE, fp)) {
+ fclose(fp);
+ return -1;
+ }
+
+ /* skip second line */
+ if (!fgets(linebuf, MAX_LINE, fp)) {
+ fclose(fp);
+ return -1;
+ }
+
+ /* read third line */
+ if (!fgets(linebuf, MAX_LINE, fp)) {
+ fclose(fp);
+ return -1;
+ }
+
+ if (strncmp(linebuf, "UTC", 3) == 0)
+ clock_mode = CM_UTC;
+ else if (strncmp(linebuf, "LOCAL", 5) == 0)
+ clock_mode = CM_LOCAL;
+
+ fclose(fp);
+
+ return 0;
+}
+
+int main(int argc, char **argv)
+{
+ char *devname = DEFAULT_DEVICE;
+ unsigned seconds = 0;
+ char *suspend = DEFAULT_MODE;
+
+ int t;
+ int fd;
+ time_t alarm = 0;
+
+ setlocale(LC_ALL, "");
+ bindtextdomain(PACKAGE, LOCALEDIR);
+ textdomain(PACKAGE);
+
+ progname = basename(argv[0]);
+
+ while ((t = getopt_long(argc, argv, "ahd:lm:s:t:uVv",
+ long_options, NULL)) != EOF) {
+ switch (t) {
+ case 'a':
+ /* CM_AUTO is default */
+ break;
+
+ case 'd':
+ devname = strdup(optarg);
+ break;
+
+ case 'l':
+ clock_mode = CM_LOCAL;
+ break;
+
+ /* what system power mode to use? for now handle only
+ * standardized mode names; eventually when systems
+ * define their own state names, parse
+ * /sys/power/state.
+ *
+ * "on" is used just to test the RTC alarm mechanism,
+ * bypassing all the wakeup-from-sleep infrastructure.
+ */
+ case 'm':
+ if (strcmp(optarg, "standby") == 0
+ || strcmp(optarg, "mem") == 0
+ || strcmp(optarg, "disk") == 0
+ || strcmp(optarg, "on") == 0
+ || strcmp(optarg, "no") == 0
+ ) {
+ suspend = strdup(optarg);
+ break;
+ }
+ fprintf(stderr,
+ _("%s: unrecognized suspend state '%s'\n"),
+ progname, optarg);
+ usage(EXIT_FAILURE);
+
+ /* alarm time, seconds-to-sleep (relative) */
+ case 's':
+ t = atoi(optarg);
+ if (t < 0) {
+ fprintf(stderr,
+ _("%s: illegal interval %s seconds\n"),
+ progname, optarg);
+ usage(EXIT_FAILURE);
+ }
+ seconds = t;
+ break;
+
+ /* alarm time, time_t (absolute, seconds since
+ * 1/1 1970 UTC)
+ */
+ case 't':
+ t = atoi(optarg);
+ if (t < 0) {
+ fprintf(stderr,
+ _("%s: illegal time_t value %s\n"),
+ progname, optarg);
+ usage(EXIT_FAILURE);
+ }
+ alarm = t;
+ break;
+
+ case 'u':
+ clock_mode = CM_UTC;
+ break;
+
+ case 'v':
+ verbose++;
+ break;
+
+ case 'V':
+ printf(_("%s: version %s\n"), progname, VERSION_STRING);
+ exit(EXIT_SUCCESS);
+
+ case 'h':
+ usage(EXIT_SUCCESS);
+
+ default:
+ usage(EXIT_FAILURE);
+ }
+ }
+
+ if (clock_mode == CM_AUTO) {
+ if (read_clock_mode() < 0) {
+ printf(_("%s: assuming RTC uses UTC ...\n"), progname);
+ clock_mode = CM_UTC;
+ }
+ }
+ if (verbose)
+ printf(clock_mode == CM_UTC ? _("Using UTC time.\n") :
+ _("Using local time.\n"));
+
+ if (!alarm && !seconds) {
+ fprintf(stderr, _("%s: must provide wake time\n"), progname);
+ usage(EXIT_FAILURE);
+ }
+
+ /* when devname doesn't start with /dev, append it */
+ if (strncmp(devname, "/dev/", strlen("/dev/")) != 0) {
+ char *new_devname;
+
+ new_devname = malloc(strlen(devname) + strlen("/dev/") + 1);
+ if (!new_devname) {
+ perror(_("malloc() failed"));
+ exit(EXIT_FAILURE);
+ }
+
+ strcpy(new_devname, "/dev/");
+ strcat(new_devname, devname);
+ free(devname);
+ devname = new_devname;
+ }
+
+ if (strcmp(suspend, "on") != 0 && strcmp(suspend, "no") != 0
+ && !is_wakeup_enabled(devname)) {
+ fprintf(stderr, _("%s: %s not enabled for wakeup events\n"),
+ progname, devname);
+ exit(EXIT_FAILURE);
+ }
+
+ /* this RTC must exist and (if we'll sleep) be wakeup-enabled */
+ fd = open(devname, O_RDONLY);
+ if (fd < 0) {
+ perror(devname);
+ exit(EXIT_FAILURE);
+ }
+
+ /* relative or absolute alarm time, normalized to time_t */
+ if (get_basetimes(fd) < 0)
+ exit(EXIT_FAILURE);
+ if (verbose)
+ printf(_("alarm %ld, sys_time %ld, rtc_time %ld, seconds %u\n"),
+ alarm, sys_time, rtc_time, seconds);
+ if (alarm) {
+ if (alarm < sys_time) {
+ fprintf(stderr,
+ _("%s: time doesn't go backward to %s\n"),
+ progname, ctime(&alarm));
+ exit(EXIT_FAILURE);
+ }
+ alarm += sys_time - rtc_time;
+ } else
+ alarm = rtc_time + seconds + 1;
+ if (setup_alarm(fd, &alarm) < 0)
+ exit(EXIT_FAILURE);
+
+ printf(_("%s: wakeup from \"%s\" using %s at %s\n"),
+ progname, suspend, devname,
+ ctime(&alarm));
+ fflush(stdout);
+ usleep(10 * 1000);
+
+ if (strcmp(suspend, "no") == 0)
+ exit(EXIT_SUCCESS);
+ else if (strcmp(suspend, "on") != 0) {
+ sync();
+ suspend_system(suspend);
+ } else {
+ unsigned long data;
+
+ do {
+ t = read(fd, &data, sizeof data);
+ if (t < 0) {
+ perror(_("rtc read"));
+ break;
+ }
+ if (verbose)
+ printf("... %s: %03lx\n", devname, data);
+ } while (!(data & RTC_AF));
+ }
+
+ if (ioctl(fd, RTC_AIE_OFF, 0) < 0)
+ perror(_("disable rtc alarm interrupt"));
+
+ close(fd);
+
+ exit(EXIT_SUCCESS);
+}
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