Documentation, split up rtc.txt into documentation and test file

This patch splits rtc.txt into two separate files, one for the
documentation itself, and the other for the rtctest.c file.  The rtctest
file is moved into the kernel tools/testing/selftests/timers directory.
This will make automated testing easier.  Note that the only difference in
the rtc.txt file is that the location of the rtctest.c file has changed.

Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Acked-by: Jonathan Corbet <corbet@lwn.net>
Acked-by: John Stultz <john.stultz@linaro.org>
Cc: corbet@lwn.net
Cc: rtc-linux@googlegroups.com
Cc: linux-doc@vger.kernel.org
Cc: a.zummo@towertech.it
Cc: prarit@redhat.com
Cc: john.stultz@linaro.org
Cc: shuahkh@osg.samsung.com
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>

2 files changed, 259 insertions, 1 deletions

diff --git a/tools/testing/selftests/timers/Makefile b/tools/testing/selftests/timers/Makefile
index 670aebdb4a99..89a3f44bf355 100644
--- a/tools/testing/selftests/timers/Makefile
+++ b/tools/testing/selftests/timers/Makefile
@@ -6,7 +6,7 @@ LDFLAGS += -lrt -lpthread
 # these are all "safe" tests that don't modify
 # system time or require escalated privledges
 TEST_PROGS = posix_timers nanosleep nsleep-lat set-timer-lat mqueue-lat \
-             inconsistency-check raw_skew threadtest
+             inconsistency-check raw_skew threadtest rtctest
 
 TEST_PROGS_EXTENDED = alarmtimer-suspend valid-adjtimex change_skew \
                       skew_consistency clocksource-switch leap-a-day \
diff --git a/tools/testing/selftests/timers/rtctest.c b/tools/testing/selftests/timers/rtctest.c
new file mode 100644
index 000000000000..1e06f4602195
--- /dev/null
+++ b/tools/testing/selftests/timers/rtctest.c
@@ -0,0 +1,258 @@
+/*
+ *      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;
+}