DeepSleepLock.h

00001 /* mbed Microcontroller Library
00002  * Copyright (c) 2017 ARM Limited
00003  *
00004  * Licensed under the Apache License, Version 2.0 (the "License");
00005  * you may not use this file except in compliance with the License.
00006  * You may obtain a copy of the License at
00007  *
00008  *     http://www.apache.org/licenses/LICENSE-2.0
00009  *
00010  * Unless required by applicable law or agreed to in writing, software
00011  * distributed under the License is distributed on an "AS IS" BASIS,
00012  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00013  * See the License for the specific language governing permissions and
00014  * limitations under the License.
00015  */
00016 #ifndef MBED_DEEPSLEEPLOCK_H
00017 #define MBED_DEEPSLEEPLOCK_H
00018 
00019 #include <limits.h>
00020 #include "platform/mbed_sleep.h"
00021 #include "platform/mbed_critical.h"
00022 
00023 namespace mbed {
00024 
00025 /** \addtogroup platform */
00026 /** @{*/
00027 /**
00028  * \defgroup platform_DeepSleepLock DeepSleepLock functions
00029  * @{
00030  */
00031 
00032 /** RAII object for disabling, then restoring the deep sleep mode
00033   * Usage:
00034   * @code
00035   *
00036   * void f() {
00037   *     // some code here
00038   *     {
00039   *         DeepSleepLock lock;
00040   *         // Code in this block will run with the deep sleep mode locked
00041   *     }
00042   *     // deep sleep mode will be restored to their previous state
00043   * }
00044   * @endcode
00045   */
00046 class DeepSleepLock {
00047 private:
00048     uint16_t _lock_count;
00049 
00050 public:
00051     DeepSleepLock(): _lock_count(1)
00052     {
00053         sleep_manager_lock_deep_sleep();
00054     }
00055 
00056     ~DeepSleepLock()
00057     {
00058         if (_lock_count) {
00059             sleep_manager_unlock_deep_sleep();
00060         }
00061     }
00062 
00063     /** Mark the start of a locked deep sleep section
00064      */
00065     void lock()
00066     {
00067         uint16_t count = core_util_atomic_incr_u16(&_lock_count, 1);
00068         if (1 == count) {
00069             sleep_manager_lock_deep_sleep();
00070         }
00071         if (0 == count) {
00072             error("DeepSleepLock overflow (> USHRT_MAX)");
00073         }
00074     }
00075 
00076     /** Mark the end of a locked deep sleep section
00077      */
00078     void unlock()
00079     {
00080         uint16_t count = core_util_atomic_decr_u16(&_lock_count, 1);
00081         if (count == 0) {
00082             sleep_manager_unlock_deep_sleep();
00083         }
00084         if (count == USHRT_MAX) {
00085             core_util_critical_section_exit();
00086             error("DeepSleepLock underflow (< 0)");
00087         }
00088     }
00089 };
00090 
00091 /**@}*/
00092 
00093 /**@}*/
00094 
00095 
00096 }
00097 
00098 #endif