kselftest: cpufreq: Add RTC wakeup alarm

Add RTC wakeup alarm for devices to resume after specific time interval.
This improvement in the test will help in enabling this test
in the CI systems and will eliminate the need of manual intervention
for resuming back the devices after suspend/hibernation.
Signed-off-by: Shreeya Patel <shreeya.patel@collabora.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

tools/testing/selftests/cpufreq/cpufreq.sh

@@ -231,6 +231,21 @@ do_suspend()
 
 		for i in `seq 1 $2`; do
 			printf "Starting $1\n"
+
+			if [ "$3" = "rtc" ]; then
+				if ! command -v rtcwake &> /dev/null; then
+					printf "rtcwake could not be found, please install it.\n"
+					return 1
+				fi
+
+				rtcwake -m $filename -s 15
+
+				if [ $? -ne 0 ]; then
+					printf "Failed to suspend using RTC wake alarm\n"
+					return 1
+				fi
+			fi
+
 			echo $filename > $SYSFS/power/state
 			printf "Came out of $1\n"
 

tools/testing/selftests/cpufreq/main.sh

@@ -24,6 +24,8 @@ helpme()
 	[-t <basic: Basic cpufreq testing
 	     suspend: suspend/resume,
 	     hibernate: hibernate/resume,
+	     suspend_rtc: suspend/resume back using the RTC wakeup alarm,
+	     hibernate_rtc: hibernate/resume back using the RTC wakeup alarm,
 	     modtest: test driver or governor modules. Only to be used with -d or -g options,
 	     sptest1: Simple governor switch to produce lockdep.
 	     sptest2: Concurrent governor switch to produce lockdep.
@@ -76,7 +78,8 @@ parse_arguments()
 				helpme
 				;;
 
-			t) # --func_type (Function to perform: basic, suspend, hibernate, modtest, sptest1/2/3/4 (default: basic))
+			t) # --func_type (Function to perform: basic, suspend, hibernate,
+			   # suspend_rtc, hibernate_rtc, modtest, sptest1/2/3/4 (default: basic))
 				FUNC=$OPTARG
 				;;
 
@@ -121,6 +124,14 @@ do_test()
 		do_suspend "hibernate" 1
 		;;
 
+		"suspend_rtc")
+                do_suspend "suspend" 1 rtc
+                ;;
+
+                "hibernate_rtc")
+                do_suspend "hibernate" 1 rtc
+                ;;
+
 		"modtest")
 		# Do we have modules in place?
 		if [ -z $DRIVER_MOD ] && [ -z $GOVERNOR_MOD ]; then