selftest: rtc: skip some tests if the alarm only supports minutes

There are alarms which have only minute-granularity. The RTC core
already has a flag to describe them. Use this flag to skip tests which
require the alarm to support seconds.

Signed-off-by: Wolfram Sang <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Alexandre Belloni <[e-mail]>

tools/testing/selftests/rtc/rtctest.c

···
 	RTC_ALARM_UNKNOWN,
 	RTC_ALARM_ENABLED,
 	RTC_ALARM_DISABLED,
+	RTC_ALARM_RES_MINUTE,
 };
 
 FIXTURE(rtc) {
···
 	}
 }
 
-static enum rtc_alarm_state get_rtc_alarm_state(int fd)
+static enum rtc_alarm_state get_rtc_alarm_state(int fd, int need_seconds)
 {
 	struct rtc_param param = { 0 };
 	int rc;
···
 
 	if ((param.uvalue & _BITUL(RTC_FEATURE_ALARM)) == 0)
 		return RTC_ALARM_DISABLED;
+
+	/* Check if alarm has desired granularity */
+	if (need_seconds && (param.uvalue & _BITUL(RTC_FEATURE_ALARM_RES_MINUTE)))
+		return RTC_ALARM_RES_MINUTE;
 
 	return RTC_ALARM_ENABLED;
 }
···
 		SKIP(return, "Skipping test since %s does not exist", rtc_file);
 	ASSERT_NE(-1, self->fd);
 
-	alarm_state = get_rtc_alarm_state(self->fd);
+	alarm_state = get_rtc_alarm_state(self->fd, 1);
 	if (alarm_state == RTC_ALARM_DISABLED)
 		SKIP(return, "Skipping test since alarms are not supported.");
+	if (alarm_state == RTC_ALARM_RES_MINUTE)
+		SKIP(return, "Skipping test since alarms has only minute granularity.");
 
 	rc = ioctl(self->fd, RTC_RD_TIME, &tm);
 	ASSERT_NE(-1, rc);
···
 		SKIP(return, "Skipping test since %s does not exist", rtc_file);
 	ASSERT_NE(-1, self->fd);
 
-	alarm_state = get_rtc_alarm_state(self->fd);
+	alarm_state = get_rtc_alarm_state(self->fd, 1);
 	if (alarm_state == RTC_ALARM_DISABLED)
 		SKIP(return, "Skipping test since alarms are not supported.");
+	if (alarm_state == RTC_ALARM_RES_MINUTE)
+		SKIP(return, "Skipping test since alarms has only minute granularity.");
 
 	rc = ioctl(self->fd, RTC_RD_TIME, &alarm.time);
 	ASSERT_NE(-1, rc);
···
 		SKIP(return, "Skipping test since %s does not exist", rtc_file);
 	ASSERT_NE(-1, self->fd);
 
-	alarm_state = get_rtc_alarm_state(self->fd);
+	alarm_state = get_rtc_alarm_state(self->fd, 0);
 	if (alarm_state == RTC_ALARM_DISABLED)
 		SKIP(return, "Skipping test since alarms are not supported.");
 
···
 		SKIP(return, "Skipping test since %s does not exist", rtc_file);
 	ASSERT_NE(-1, self->fd);
 
-	alarm_state = get_rtc_alarm_state(self->fd);
+	alarm_state = get_rtc_alarm_state(self->fd, 0);
 	if (alarm_state == RTC_ALARM_DISABLED)
 		SKIP(return, "Skipping test since alarms are not supported.");