1 files changed, 134 insertions, 0 deletions

diff --git a/tools/testing/selftests/timers/rtcpie.c b/tools/testing/selftests/timers/rtcpie.c
new file mode 100644
index 000000000000..47b5bad1b393
--- /dev/null
+++ b/tools/testing/selftests/timers/rtcpie.c
@@ -0,0 +1,134 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Real Time Clock Periodic Interrupt test program
+ *
+ * Since commit 6610e0893b8bc ("RTC: Rework RTC code to use timerqueue for
+ * events"), PIE are completely handled using hrtimers, without actually using
+ * any underlying hardware RTC.
+ *
+ */
+
+#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, old_pie_rate;
+        const char *rtc = default_rtc;
+        struct timeval start, end, diff;
+
+        switch (argc) {
+        case 2:
+                rtc = argv[1];
+                /* FALLTHROUGH */
+        case 1:
+                break;
+        default:
+                fprintf(stderr, "usage:  rtctest [rtcdev] [d]\n");
+                return 1;
+        }
+
+        fd = open(rtc, O_RDONLY);
+
+        if (fd ==  -1) {
+                perror(rtc);
+                exit(errno);
+        }
+
+        /* Read periodic IRQ rate */
+        retval = ioctl(fd, RTC_IRQP_READ, &old_pie_rate);
+        if (retval == -1) {
+                /* not all RTCs support periodic IRQs */
+                if (errno == EINVAL) {
+                        fprintf(stderr, "\nNo periodic IRQ support\n");
+                        goto done;
+                }
+                perror("RTC_IRQP_READ ioctl");
+                exit(errno);
+        }
+        fprintf(stderr, "\nPeriodic IRQ rate is %ldHz.\n", old_pie_rate);
+
+        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 == EINVAL) {
+                                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++) {
+                        gettimeofday(&start, NULL);
+                        /* This blocks */
+                        retval = read(fd, &data, sizeof(unsigned long));
+                        if (retval == -1) {
+                                perror("read");
+                                exit(errno);
+                        }
+                        gettimeofday(&end, NULL);
+                        timersub(&end, &start, &diff);
+                        if (diff.tv_sec > 0 ||
+                            diff.tv_usec > ((1000000L / tmp) * 1.10)) {
+                                fprintf(stderr, "\nPIE delta error: %ld.%06ld should be close to 0.%06ld\n",
+                                       diff.tv_sec, diff.tv_usec,
+                                       (1000000L / tmp));
+                                fflush(stdout);
+                                exit(-1);
+                        }
+
+                        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:
+        ioctl(fd, RTC_IRQP_SET, old_pie_rate);
+
+        fprintf(stderr, "\n\n\t\t\t *** Test complete ***\n");
+
+        close(fd);
+
+        return 0;
+}