--- zzzz-none-000/linux-3.10.107/Documentation/rtc.txt	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/Documentation/rtc.txt	2021-02-04 17:41:59.000000000 +0000
@@ -153,9 +153,10 @@
 time:		 RTC-provided time
 wakealarm:	 The time at which the clock will generate a system wakeup
 		 event. This is a one shot wakeup event, so must be reset
-		 after wake if a daily wakeup is required. Format is either
-		 seconds since the epoch or, if there's a leading +, seconds
-		 in the future.
+		 after wake if a daily wakeup is required. Format is seconds since
+		 the epoch by default, or if there's a leading +, seconds in the
+		 future, or if there is a leading +=, seconds ahead of the current
+		 alarm.
 
 IOCTL INTERFACE
 ---------------
@@ -203,266 +204,4 @@
 
     *	RTC_PIE_ON, RTC_PIE_OFF: These are also emulated by the generic code.
 
-If all else fails, check out the rtc-test.c driver!
-
-
--------------------- 8< ---------------- 8< -----------------------------
-
-/*
- *      Real Time Clock Driver Test/Example Program
- *
- *      Compile with:
- *		     gcc -s -Wall -Wstrict-prototypes rtctest.c -o rtctest
- *
- *      Copyright (C) 1996, Paul Gortmaker.
- *
- *      Released under the GNU General Public License, version 2,
- *      included herein by reference.
- *
- */
-
-#include <stdio.h>
-#include <linux/rtc.h>
-#include <sys/ioctl.h>
-#include <sys/time.h>
-#include <sys/types.h>
-#include <fcntl.h>
-#include <unistd.h>
-#include <stdlib.h>
-#include <errno.h>
-
-
-/*
- * This expects the new RTC class driver framework, working with
- * clocks that will often not be clones of what the PC-AT had.
- * Use the command line to specify another RTC if you need one.
- */
-static const char default_rtc[] = "/dev/rtc0";
-
-
-int main(int argc, char **argv)
-{
-	int i, fd, retval, irqcount = 0;
-	unsigned long tmp, data;
-	struct rtc_time rtc_tm;
-	const char *rtc = default_rtc;
-
-	switch (argc) {
-	case 2:
-		rtc = argv[1];
-		/* FALLTHROUGH */
-	case 1:
-		break;
-	default:
-		fprintf(stderr, "usage:  rtctest [rtcdev]\n");
-		return 1;
-	}
-
-	fd = open(rtc, O_RDONLY);
-
-	if (fd ==  -1) {
-		perror(rtc);
-		exit(errno);
-	}
-
-	fprintf(stderr, "\n\t\t\tRTC Driver Test Example.\n\n");
-
-	/* Turn on update interrupts (one per second) */
-	retval = ioctl(fd, RTC_UIE_ON, 0);
-	if (retval == -1) {
-		if (errno == ENOTTY) {
-			fprintf(stderr,
-				"\n...Update IRQs not supported.\n");
-			goto test_READ;
-		}
-		perror("RTC_UIE_ON ioctl");
-		exit(errno);
-	}
-
-	fprintf(stderr, "Counting 5 update (1/sec) interrupts from reading %s:",
-			rtc);
-	fflush(stderr);
-	for (i=1; i<6; i++) {
-		/* This read will block */
-		retval = read(fd, &data, sizeof(unsigned long));
-		if (retval == -1) {
-			perror("read");
-			exit(errno);
-		}
-		fprintf(stderr, " %d",i);
-		fflush(stderr);
-		irqcount++;
-	}
-
-	fprintf(stderr, "\nAgain, from using select(2) on /dev/rtc:");
-	fflush(stderr);
-	for (i=1; i<6; i++) {
-		struct timeval tv = {5, 0};     /* 5 second timeout on select */
-		fd_set readfds;
-
-		FD_ZERO(&readfds);
-		FD_SET(fd, &readfds);
-		/* The select will wait until an RTC interrupt happens. */
-		retval = select(fd+1, &readfds, NULL, NULL, &tv);
-		if (retval == -1) {
-		        perror("select");
-		        exit(errno);
-		}
-		/* This read won't block unlike the select-less case above. */
-		retval = read(fd, &data, sizeof(unsigned long));
-		if (retval == -1) {
-		        perror("read");
-		        exit(errno);
-		}
-		fprintf(stderr, " %d",i);
-		fflush(stderr);
-		irqcount++;
-	}
-
-	/* Turn off update interrupts */
-	retval = ioctl(fd, RTC_UIE_OFF, 0);
-	if (retval == -1) {
-		perror("RTC_UIE_OFF ioctl");
-		exit(errno);
-	}
-
-test_READ:
-	/* Read the RTC time/date */
-	retval = ioctl(fd, RTC_RD_TIME, &rtc_tm);
-	if (retval == -1) {
-		perror("RTC_RD_TIME ioctl");
-		exit(errno);
-	}
-
-	fprintf(stderr, "\n\nCurrent RTC date/time is %d-%d-%d, %02d:%02d:%02d.\n",
-		rtc_tm.tm_mday, rtc_tm.tm_mon + 1, rtc_tm.tm_year + 1900,
-		rtc_tm.tm_hour, rtc_tm.tm_min, rtc_tm.tm_sec);
-
-	/* Set the alarm to 5 sec in the future, and check for rollover */
-	rtc_tm.tm_sec += 5;
-	if (rtc_tm.tm_sec >= 60) {
-		rtc_tm.tm_sec %= 60;
-		rtc_tm.tm_min++;
-	}
-	if (rtc_tm.tm_min == 60) {
-		rtc_tm.tm_min = 0;
-		rtc_tm.tm_hour++;
-	}
-	if (rtc_tm.tm_hour == 24)
-		rtc_tm.tm_hour = 0;
-
-	retval = ioctl(fd, RTC_ALM_SET, &rtc_tm);
-	if (retval == -1) {
-		if (errno == ENOTTY) {
-			fprintf(stderr,
-				"\n...Alarm IRQs not supported.\n");
-			goto test_PIE;
-		}
-		perror("RTC_ALM_SET ioctl");
-		exit(errno);
-	}
-
-	/* Read the current alarm settings */
-	retval = ioctl(fd, RTC_ALM_READ, &rtc_tm);
-	if (retval == -1) {
-		perror("RTC_ALM_READ ioctl");
-		exit(errno);
-	}
-
-	fprintf(stderr, "Alarm time now set to %02d:%02d:%02d.\n",
-		rtc_tm.tm_hour, rtc_tm.tm_min, rtc_tm.tm_sec);
-
-	/* Enable alarm interrupts */
-	retval = ioctl(fd, RTC_AIE_ON, 0);
-	if (retval == -1) {
-		perror("RTC_AIE_ON ioctl");
-		exit(errno);
-	}
-
-	fprintf(stderr, "Waiting 5 seconds for alarm...");
-	fflush(stderr);
-	/* This blocks until the alarm ring causes an interrupt */
-	retval = read(fd, &data, sizeof(unsigned long));
-	if (retval == -1) {
-		perror("read");
-		exit(errno);
-	}
-	irqcount++;
-	fprintf(stderr, " okay. Alarm rang.\n");
-
-	/* Disable alarm interrupts */
-	retval = ioctl(fd, RTC_AIE_OFF, 0);
-	if (retval == -1) {
-		perror("RTC_AIE_OFF ioctl");
-		exit(errno);
-	}
-
-test_PIE:
-	/* Read periodic IRQ rate */
-	retval = ioctl(fd, RTC_IRQP_READ, &tmp);
-	if (retval == -1) {
-		/* not all RTCs support periodic IRQs */
-		if (errno == ENOTTY) {
-			fprintf(stderr, "\nNo periodic IRQ support\n");
-			goto done;
-		}
-		perror("RTC_IRQP_READ ioctl");
-		exit(errno);
-	}
-	fprintf(stderr, "\nPeriodic IRQ rate is %ldHz.\n", tmp);
-
-	fprintf(stderr, "Counting 20 interrupts at:");
-	fflush(stderr);
-
-	/* The frequencies 128Hz, 256Hz, ... 8192Hz are only allowed for root. */
-	for (tmp=2; tmp<=64; tmp*=2) {
-
-		retval = ioctl(fd, RTC_IRQP_SET, tmp);
-		if (retval == -1) {
-			/* not all RTCs can change their periodic IRQ rate */
-			if (errno == ENOTTY) {
-				fprintf(stderr,
-					"\n...Periodic IRQ rate is fixed\n");
-				goto done;
-			}
-			perror("RTC_IRQP_SET ioctl");
-			exit(errno);
-		}
-
-		fprintf(stderr, "\n%ldHz:\t", tmp);
-		fflush(stderr);
-
-		/* Enable periodic interrupts */
-		retval = ioctl(fd, RTC_PIE_ON, 0);
-		if (retval == -1) {
-			perror("RTC_PIE_ON ioctl");
-			exit(errno);
-		}
-
-		for (i=1; i<21; i++) {
-			/* This blocks */
-			retval = read(fd, &data, sizeof(unsigned long));
-			if (retval == -1) {
-				perror("read");
-				exit(errno);
-			}
-			fprintf(stderr, " %d",i);
-			fflush(stderr);
-			irqcount++;
-		}
-
-		/* Disable periodic interrupts */
-		retval = ioctl(fd, RTC_PIE_OFF, 0);
-		if (retval == -1) {
-			perror("RTC_PIE_OFF ioctl");
-			exit(errno);
-		}
-	}
-
-done:
-	fprintf(stderr, "\n\n\t\t\t *** Test complete ***\n");
-
-	close(fd);
-
-	return 0;
-}
+If all else fails, check out the tools/testing/selftests/timers/rtctest.c test!