test/automated: PWM duty cycle verification test using GPIO loopback

test/mtest/mtest_pwm/include/mtest_pwm/mtest_pwm.h

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+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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.
+ */
+
+#ifndef MTEST_PWM_H
+#define MTEST_PWM_H
+#include "mtest/mtest.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define PWM_TEST_DEV MYNEWT_VAL(PWM_TEST_DEV_NAME)
+
+#define TIMER_FREQ_HZ  MYNEWT_VAL(OS_CPUTIME_FREQ)
+#define SAMPLE_FREQ_HZ 1000
+#define PWM_FREQ_HZ    200
+
+#define TIMER_TICKS    (TIMER_FREQ_HZ / SAMPLE_FREQ_HZ)
+#define MEASURE_TIME_S 1
+#define WINDOW_SIZE    (SAMPLE_FREQ_HZ * MEASURE_TIME_S)
+
+#if MYNEWT_VAL(BSP_IS_NUCLEO)
+#define PWM_TEST_CH_CFG_PIN                                                   \
+    MCU_AFIO_GPIO(MYNEWT_VAL(PWM_TEST_OUT_PIN), MYNEWT_VAL(PWM_TEST_OUT_PIN_AF))
+#else
+#define PWM_TEST_CH_CFG_PIN MYNEWT_VAL(PWM_TEST_OUT_PIN)
+#endif
+#define PWM_TEST_CH_NUM     MYNEWT_VAL(PWM_TEST_CHANNEL)
+#define PWM_TEST_CH_CFG_INV MYNEWT_VAL(PWM_TEST_INVERT_OUTPUT)
+
+struct pwm_test_ctx {
+    struct pwm_dev *pwm;
+    struct os_sem sem;
+    struct hal_timer timer;
+
+    int sample_cnt;
+    int high_cnt;
+};
+
+extern struct pwm_test_ctx test_ctx;
+
+MTEST_CASE_DECL(pwm_test_case_1);
+MTEST_CASE_DECL(pwm_test_case_2);
+MTEST_CASE_DECL(pwm_test_case_3);
+MTEST_CASE_DECL(pwm_test_case_4);
+MTEST_CASE_DECL(pwm_test_case_5);
+MTEST_CASE_DECL(pwm_test_case_6);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

test/mtest/mtest_pwm/pkg.yml

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+#
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you 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.
+#
+
+pkg.name: test/mtest/mtest_pwm
+pkg.description: PWM duty cycle verification via GPIO loopback
+pkg.author: "Apache Mynewt <dev@mynewt.apache.org>"
+pkg.homepage: "http://mynewt.apache.org/"
+pkg.keywords:
+pkg.type: app
+pkg.deps:
+    - "@apache-mynewt-core/kernel/os"
+    - "@apache-mynewt-core/hw/hal"
+    - "@apache-mynewt-core/sys/log/"
+    - "@apache-mynewt-core/hw/drivers/pwm"
+    - "@apache-mynewt-core/test/mtest/mtest"
+    - "@apache-mynewt-core/hw/drivers/pwm"

test/mtest/mtest_pwm/src/main.c

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+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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 "sysinit/sysinit.h"
+#include "bsp/bsp.h"
+#include "pwm/pwm.h"
+#include "hal/hal_gpio.h"
+#include "mtest_pwm/mtest_pwm.h"
+
+struct pwm_test_ctx test_ctx;
+
+void
+pwm_init(void)
+{
+    struct pwm_chan_cfg chan_conf;
+    int rc;
+
+    chan_conf = (struct pwm_chan_cfg){ .pin = PWM_TEST_CH_CFG_PIN,
+                                       .inverted = PWM_TEST_CH_CFG_INV,
+                                       .data = NULL };
+
+    test_ctx.pwm =
+        (struct pwm_dev *)os_dev_open(PWM_TEST_DEV, OS_TIMEOUT_NEVER, NULL);
+    MTEST_INIT_ASSERT(test_ctx.pwm != NULL, "device %s not available\n", PWM_TEST_DEV);
+    rc = pwm_set_frequency(test_ctx.pwm, PWM_FREQ_HZ);
+    MTEST_INIT_ASSERT(rc > 0, "set frequency for pwm clock failed");
+
+    rc = pwm_configure_channel(test_ctx.pwm, PWM_TEST_CH_NUM, &chan_conf);
+    MTEST_INIT_ASSERT(rc == 0, "channel configuration failed");
+
+    rc = pwm_enable(test_ctx.pwm);
+    MTEST_INIT_ASSERT(rc == 0, "PWM enable");
+}
+
+void
+timer_cb(void *arg)
+{
+    if (test_ctx.sample_cnt < WINDOW_SIZE) {
+        test_ctx.sample_cnt++;
+        if (hal_gpio_read(MYNEWT_VAL(PWM_TEST_READ_PIN))) {
+            test_ctx.high_cnt++;
+        }
+
+        if (test_ctx.sample_cnt == WINDOW_SIZE) {
+            os_cputime_timer_stop(&test_ctx.timer);
+            os_sem_release(&test_ctx.sem);
+        } else {
+            os_cputime_timer_relative(&test_ctx.timer, TIMER_TICKS);
+        }
+    }
+}
+
+MTEST_INIT(pwm_test)
+{
+    int rc;
+    os_error_t err;
+
+    rc = hal_gpio_init_in(MYNEWT_VAL(PWM_TEST_READ_PIN), HAL_GPIO_PULL_DOWN);
+    MTEST_INIT_ASSERT(rc == 0, "pin configuration failed");
+
+    err = os_sem_init(&test_ctx.sem, 0);
+    MTEST_INIT_ASSERT(err == 0, "semaphore init failed");
+
+    os_cputime_timer_init(&test_ctx.timer, timer_cb, NULL);
+
+    pwm_init();
+}
+
+MTEST_CLEANUP(pwm_test)
+{
+    int rc;
+
+    rc = pwm_disable(test_ctx.pwm);
+    MTEST_CLEANUP_ASSERT(rc == 0, "disable PWM failed");
+
+    os_cputime_timer_stop(&test_ctx.timer);
+
+    rc = os_dev_close((struct os_dev *)test_ctx.pwm);
+    MTEST_CLEANUP_ASSERT(rc == 0, "dev close failed");
+}
+
+MTEST_SUITE(pwm_test)
+{
+    MTEST_RUN_INIT(pwm_test);
+    pwm_test_case_1();
+    pwm_test_case_2();
+    pwm_test_case_3();
+    pwm_test_case_4();
+    pwm_test_case_5();
+    pwm_test_case_6();
+    MTEST_RUN_CLEANUP(pwm_test);
+}
+
+int
+mynewt_main(int argc, char **argv)
+{
+    sysinit();
+
+    pwm_test();
+
+    while (1) {
+        os_time_delay(OS_TICKS_PER_SEC);
+    }
+}

test/mtest/mtest_pwm/src/pwm_test_cases.c

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+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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 "pwm/pwm.h"
+#include "mtest_pwm/mtest_pwm.h"
+
+void
+test_pwm_duty_cycle(int duty_percent)
+{
+    int top;
+    int duty_val;
+    int rc;
+    int measured_duty;
+    int diff;
+    test_ctx.sample_cnt = 0;
+    test_ctx.high_cnt = 0;
+
+    top = pwm_get_top_value(test_ctx.pwm);
+    MTEST_CASE_ASSERT(top > 0, "PWM get top value failed");
+
+    duty_val = top * duty_percent / 100;
+    rc = pwm_set_duty_cycle(test_ctx.pwm, PWM_TEST_CH_NUM, duty_val);
+    MTEST_CASE_ASSERT(rc == 0, "set duty cycle %u%% (value=%d) failed",
+                      duty_percent, duty_val);
+
+    rc = os_cputime_timer_relative(&test_ctx.timer, TIMER_TICKS);
+    MTEST_CASE_ASSERT(rc == 0, "timer start failed");
+
+    rc = os_sem_pend(&test_ctx.sem, OS_TICKS_PER_SEC * 10);
+    MTEST_CASE_ASSERT(rc == 0, "measurement timeout for duty %d%%", duty_percent);
+
+    MTEST_CASE_ASSERT(test_ctx.sample_cnt > 0, "no samples collected");
+
+    measured_duty = test_ctx.high_cnt * 100 / test_ctx.sample_cnt;
+    diff = measured_duty - duty_percent;
+    if (diff < 0) {
+        diff = -diff;
+    }
+
+    MTEST_CASE_ASSERT(
+        diff < MYNEWT_VAL(PWM_TEST_TOLERANCE),
+        "duty tolerance exceeded: expected %d%%, measured %d%%, diff %d%% (max %d%%)",
+        duty_percent, measured_duty, diff, MYNEWT_VAL(PWM_TEST_TOLERANCE));
+}
+
+MTEST_CASE(pwm_test_case_1)
+{
+    test_pwm_duty_cycle(0);
+}
+
+MTEST_CASE(pwm_test_case_2)
+{
+    test_pwm_duty_cycle(20);
+}
+
+MTEST_CASE(pwm_test_case_3)
+{
+    test_pwm_duty_cycle(40);
+}
+
+MTEST_CASE(pwm_test_case_4)
+{
+    test_pwm_duty_cycle(60);
+}
+
+MTEST_CASE(pwm_test_case_5)
+{
+    test_pwm_duty_cycle(80);
+}
+
+MTEST_CASE(pwm_test_case_6)
+{
+    test_pwm_duty_cycle(100);
+}