Simulated product dispenser

Dependencies:   HTS221

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Show/hide line numbers critical-nordic.c Source File

critical-nordic.c

00001 // ----------------------------------------------------------------------------
00002 // Copyright 2015-2017 ARM Ltd.
00003 //
00004 // SPDX-License-Identifier: Apache-2.0
00005 //
00006 // Licensed under the Apache License, Version 2.0 (the "License");
00007 // you may not use this file except in compliance with the License.
00008 // You may obtain a copy of the License at
00009 //
00010 //     http://www.apache.org/licenses/LICENSE-2.0
00011 //
00012 // Unless required by applicable law or agreed to in writing, software
00013 // distributed under the License is distributed on an "AS IS" BASIS,
00014 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00015 // See the License for the specific language governing permissions and
00016 // limitations under the License.
00017 // ----------------------------------------------------------------------------
00018 
00019 #ifdef TARGET_MCU_NRF51
00020 
00021 #include <stdint.h>                  // uint32_t, UINT32_MAX
00022 #include <stddef.h>                  // NULL
00023 #include <cmsis-core/core_generic.h> //__disable_irq, __enable_irq
00024 #include <assert.h>
00025 #include <stdbool.h>
00026 #include <nrf_soc.h>
00027 #include <nrf_sdm.h>
00028 
00029 // Module include
00030 #include "aq_critical.h"
00031 
00032 static volatile union {
00033     uint32_t _PRIMASK_state;
00034     uint8_t  _sd_state;
00035 } _state = { 0 } ;
00036 static volatile uint32_t _entry_count = 0;
00037 static volatile bool _use_softdevice_routine = false;
00038 
00039 void aq_critical_section_enter()
00040 {
00041     // if a critical section has already been entered, just update the counter
00042     if (_entry_count) {
00043         ++_entry_count;
00044         return;
00045     }
00046 
00047     // in this path, a critical section has never been entered
00048     uint32_t primask = __get_PRIMASK();
00049 
00050     // if interrupts are enabled, try to use the soft device
00051     uint8_t sd_enabled;
00052     if ((primask == 0) && (sd_softdevice_is_enabled(&sd_enabled) == NRF_SUCCESS) && sd_enabled == 1) {
00053         // if the soft device can be use, use it
00054         sd_nvic_critical_region_enter(&_state._sd_state);
00055         _use_softdevice_routine = true;
00056     } else {
00057         // if interrupts where enabled, disable them
00058         if(primask == 0) {
00059             __disable_irq();
00060         }
00061 
00062         // store the PRIMASK state, it will be restored at the end of the critical section
00063         _state._PRIMASK_state = primask;
00064         _use_softdevice_routine = false;
00065     }
00066 
00067     assert(_entry_count == 0); // entry count should always be equal to 0 at this point
00068     ++_entry_count;
00069 }
00070 
00071 void aq_critical_section_exit(void)
00072 {
00073     assert(_entry_count > 0);
00074     --_entry_count;
00075 
00076     // If their is other segments which have entered the critical section, just leave
00077     if (_entry_count) {
00078         return;
00079     }
00080 
00081     // This is the last segment of the critical section, state should be restored as before entering
00082     // the critical section
00083     if (_use_softdevice_routine) {
00084         sd_nvic_critical_region_exit(_state._sd_state);
00085     } else {
00086         __set_PRIMASK(_state._PRIMASK_state);
00087     }
00088 }
00089 
00090 #endif //TARGET_MCU_NRF51