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;
+}