applications/message_handler/lib/core_driver_mutex.cpp

/*
 * Copyright (c) 2022 Arm Limited.
 *
 * 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
 *
 * 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.
 */

#if defined(ETHOSU)

#include "FreeRTOS.h"
#include "semphr.h"

#include <ethosu_driver.h>
#include <stdio.h>

extern "C" {

void *ethosu_mutex_create(void) {
    return xSemaphoreCreateMutex();
}

int ethosu_mutex_lock(void *mutex) {
    SemaphoreHandle_t handle = reinterpret_cast<SemaphoreHandle_t>(mutex);
    if (xSemaphoreTake(handle, portMAX_DELAY) != pdTRUE) {
        printf("Error: Failed to lock mutex.\n");
        return -1;
    }
    return 0;
}

int ethosu_mutex_unlock(void *mutex) {
    SemaphoreHandle_t handle = reinterpret_cast<SemaphoreHandle_t>(mutex);
    if (xSemaphoreGive(handle) != pdTRUE) {
        printf("Error: Failed to unlock mutex.\n");
        return -1;
    }
    return 0;
}

void *ethosu_semaphore_create(void) {
    return xSemaphoreCreateBinary();
}

int ethosu_semaphore_take(void *sem) {
    SemaphoreHandle_t handle = reinterpret_cast<SemaphoreHandle_t>(sem);
    if (xSemaphoreTake(handle, portMAX_DELAY) != pdTRUE) {
        printf("Error: Failed to take semaphore.\n");
        return -1;
    }
    return 0;
}

int ethosu_semaphore_give(void *sem) {
    SemaphoreHandle_t handle = reinterpret_cast<SemaphoreHandle_t>(sem);
    if (xPortIsInsideInterrupt()) {
        if (xSemaphoreGiveFromISR(handle, NULL) != pdTRUE) {
            printf("Error: Failed to give semaphore from ISR.\n");
            return -1;
        }
    } else {
        /* A FreeRTOS binary semaphore is fundamentally a queue that can only hold one item. If the queue is full,
         * xSemaphoreGive will return a pdFALSE value. Ignoring the return value in here, as a semaphore give failure
         * does not affect the application correctness. */
        if (xSemaphoreGive(handle) != pdTRUE) {
            // do nothing
        }
    }
    return 0;
}
}

#endif