misc-util: new rtcwake command

Signed-off-by: Bernhard Walle <bwalle@suse.de>
Signed-off-by: Karel Zak <kzak@redhat.com>

1 files changed, 465 insertions, 0 deletions

diff --git a/sys-utils/rtcwake.c b/sys-utils/rtcwake.c
new file mode 100644
index 000000000..4ba81e4c1
--- /dev/null
+++ b/sys-utils/rtcwake.c
@@ -0,0 +1,465 @@
+/*
+ * 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).
+ */
+
+#include <stdio.h>
+#include <getopt.h>
+#include <fcntl.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"
+
+/* 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_SATE_PATH	"/sys/power/state"
+#define ADJTIME_PATH		"/etc/adjtime"
+#define DEFAULT_DEVICE		"/dev/rtc0"
+#define DEFAULT_MODE		"suspend"
+
+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 may_wakeup(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 0;
+	}
+	sys_time = time(0);
+	if (sys_time == (time_t)-1) {
+		perror(_("read system time"));
+		return 0;
+	}
+
+	/* 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 0;
+	}
+
+	if (verbose) {
+		if (clock_mode == CM_LOCAL) {
+			printf("\ttzone   = %ld\n", timezone);
+			printf("\ttzname  = %s\n", tzname[daylight]);
+			gmtime_r(&rtc_time, &tm);
+		}
+		printf("\tsystime = %ld, (UTC) %s\n",
+				(long) sys_time, asctime(gmtime(&sys_time)));
+		printf("\trtctime = %ld, (UTC) %s\n",
+				(long) rtc_time, asctime(&tm));
+	}
+
+	return 1;
+}
+
+static int setup_alarm(int fd, time_t *wakeup)
+{
+	struct tm		*tm;
+	struct rtc_wkalrm	wake;
+
+	tm = gmtime(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;
+	wake.time.tm_wday = tm->tm_wday;
+	wake.time.tm_yday = tm->tm_yday;
+	wake.time.tm_isdst = tm->tm_isdst;
+
+	/* many rtc alarms only support up to 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 0;
+		}
+		if (ioctl(fd, RTC_AIE_ON, 0) < 0) {
+			perror(_("enable rtc alarm"));
+			return 0;
+		}
+
+		/* ... so use the "more than 24 hours" request only if we must */
+	} else {
+		/* avoid an extra AIE_ON call */
+		wake.enabled = 1;
+
+		if (ioctl(fd, RTC_WKALM_SET, &wake) < 0) {
+			perror(_("set rtc wake alarm"));
+			return 0;
+		}
+	}
+
+	return 1;
+}
+
+static void suspend_system(const char *suspend)
+{
+	FILE	*f = fopen(SYS_POWER_SATE_PATH, "w");
+
+	if (!f) {
+		perror(SYS_POWER_SATE_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 0;
+
+	/* skip first line */
+	if (!fgets(linebuf, MAX_LINE, fp)) {
+		fclose(fp);
+		return 0;
+	}
+
+	/* skip second line */
+	if (!fgets(linebuf, MAX_LINE, fp)) {
+		fclose(fp);
+		return 0;
+	}
+
+	/* read third line */
+	if (!fgets(linebuf, MAX_LINE, fp)) {
+		fclose(fp);
+		return 0;
+	}
+
+	if (strncmp(linebuf, "UTC", 3) == 0)
+		clock_mode = CM_UTC;
+	else if (strncmp(linebuf, "LOCAL", 5) == 0)
+		clock_mode = CM_LOCAL;
+
+	fclose(fp);
+
+	return 1;
+}
+
+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
+			   ) {
+				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()) {
+			printf(_("%s: assuming RTC uses UTC ...\n"), progname);
+			clock_mode = CM_UTC;
+		}
+		if (verbose)
+			printf(_("Using %s time\n"),
+					clock_mode == CM_UTC ? "UTC" : _("local"));
+	}
+
+	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 && !may_wakeup(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))
+		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);
+
+	sync();
+	printf(_("%s: wakeup from \"%s\" using %s at %s\n"),
+			progname, suspend, devname,
+			ctime(&alarm));
+	fflush(stdout);
+	usleep(10 * 1000);
+
+	if (strcmp(suspend, "on") != 0)
+		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);
+}