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-rw-r--r--tools/testing/selftests/timers/rtcpie.c134
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;
+}