test: add rtos idle loop

Basic functionality, to test wait() with tickless.

This is not accurancy test, just that an application
wakes up within the expected period + some margin.

Author: 0xc0170

TESTS/mbedmicro-rtos-mbed/idle_loop/main.cpp

@@ -0,0 +1,69 @@
+/*
+ * Copyright (c) 2017, ARM Limited, All Rights Reserved
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "mbed.h"
+#include "rtos.h"
+#include "greentea-client/test_env.h"
+#include "unity/unity.h"
+#include "utest/utest.h"
+
+#if !DEVICE_LOWPOWERTIMER
+    #error [NOT_SUPPORTED] Low power timer not supported for this target
+#endif
+
+using namespace utest::v1;
+
+template<timestamp_t time_ms>
+void idle_loop_test_sleep_ms()
+{
+    LowPowerTimer timer;
+    timer.start();
+    wait_ms(time_ms);
+    const timestamp_t end = timer.read_ms();
+
+    // this does not test accurancy for waking up
+    // just that we are with some margin awake (10ms)
+    // sleep/low power ticker will test this
+    TEST_ASSERT_UINT32_WITHIN(10, time_ms, end);
+}
+
+utest::v1::status_t greentea_failure_handler(const Case *const source, const failure_t reason) 
+{
+    greentea_case_failure_abort_handler(source, reason);
+    return STATUS_CONTINUE;
+}
+
+Case cases[] = {
+    Case("Idle loop - sleep for 10 ms", idle_loop_test_sleep_ms<10>, greentea_failure_handler),
+    Case("Idle loop - sleep for 100 ms", idle_loop_test_sleep_ms<100>, greentea_failure_handler),
+    Case("Idle loop - sleep for 500 ms", idle_loop_test_sleep_ms<500>, greentea_failure_handler),
+    Case("Idle loop - sleep for 5 s", idle_loop_test_sleep_ms<5000>, greentea_failure_handler),
+};
+
+utest::v1::status_t greentea_test_setup(const size_t number_of_cases) 
+{
+    GREENTEA_SETUP(25, "default_auto");
+    return greentea_test_setup_handler(number_of_cases);
+}
+
+Specification specification(greentea_test_setup, cases, greentea_test_teardown_handler);
+
+int main() 
+{
+    Harness::run(specification);
+}
+