mbed-os/TESTS/mbed_platform/wait_ns/main.cpp

102 lines
3.0 KiB
C++

/*
* Copyright (c) 2018, 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 "greentea-client/test_env.h"
#include "unity.h"
#include "utest.h"
#include "platform/mbed_wait_api.h"
#include "hal/us_ticker_api.h"
#include "hal/lp_ticker_api.h"
//FastModels not support timing test
#if defined(__ARM_FM)
#error [NOT_SUPPORTED] test not supported
#endif
using namespace utest::v1;
/* This test is created based on the test for Timer class.
* Since low power timer is less accurate than regular
* timer we need to adjust delta.
*/
/*
* Define tolerance as follows:
* Timer might be +/-5% out; wait_ns is permitted 40% slow, but not fast.
* Therefore minimum measured time should be 95% of requested, maximum should
* be 145%. Unity doesn't let us specify an asymmetric error though.
*
* Would be nice to have tighter upper tolerance, but in practice we've seen
* a few devices unable to sustain theoretical throughput - flash wait states?
*/
#define TOLERANCE_MIN 0.95f
#define TOLERANCE_MAX 1.45f
#define MIDPOINT ((TOLERANCE_MIN+TOLERANCE_MAX)/2)
#define DELTA (MIDPOINT-TOLERANCE_MIN)
/* This test verifies if wait_ns's wait time
* is accurate, according to a timer.
*
* Given timer is created.
* When timer is used to measure delay.
* Then the results are valid (within acceptable range).
*/
template<int wait_val_ms, class CompareTimer>
void test_wait_ns_time_measurement()
{
CompareTimer timer;
float wait_val_s = (float)wait_val_ms / 1000;
/* Start the timer. */
timer.start();
/* Wait <wait_val_ms> ms - arithmetic inside wait_ns will overflow if
* asked for too large a delay, so break it up.
*/
for (int i = 0; i < wait_val_ms; i++) {
wait_ns(1000000);
}
/* Stop the timer. */
timer.stop();
/* Check results - wait_val_us us have elapsed. */
TEST_ASSERT_FLOAT_WITHIN(DELTA * wait_val_s, MIDPOINT * wait_val_s, timer.read());
}
utest::v1::status_t test_setup(const size_t number_of_cases)
{
GREENTEA_SETUP(15, "default_auto");
return verbose_test_setup_handler(number_of_cases);
}
Case cases[] = {
#if DEVICE_LPTICKER
Case("Test: wait_ns - compare with lp_timer 1s", test_wait_ns_time_measurement<1000, LowPowerTimer>),
#endif
Case("Test: wait_ns - compare with us_timer 1s", test_wait_ns_time_measurement<1000, Timer>)
};
Specification specification(test_setup, cases);
int main()
{
return !Harness::run(specification);
}