Subversion Repositories dashGPS

Rev

Go to most recent revision | Blame | Compare with Previous | Last modification | View Log | Download | RSS feed

  1. /**************************************************************************//**
  2.  * @file     os_systick.c
  3.  * @brief    CMSIS OS Tick SysTick implementation
  4.  * @version  V1.0.1
  5.  * @date     24. November 2017
  6.  ******************************************************************************/
  7. /*
  8.  * Copyright (c) 2017-2017 ARM Limited. All rights reserved.
  9.  *
  10.  * SPDX-License-Identifier: Apache-2.0
  11.  *
  12.  * Licensed under the Apache License, Version 2.0 (the License); you may
  13.  * not use this file except in compliance with the License.
  14.  * You may obtain a copy of the License at
  15.  *
  16.  * www.apache.org/licenses/LICENSE-2.0
  17.  *
  18.  * Unless required by applicable law or agreed to in writing, software
  19.  * distributed under the License is distributed on an AS IS BASIS, WITHOUT
  20.  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  21.  * See the License for the specific language governing permissions and
  22.  * limitations under the License.
  23.  */
  24.  
  25. #include "os_tick.h"
  26.  
  27. //lint -emacro((923,9078),SCB,SysTick) "cast from unsigned long to pointer"
  28. #include "RTE_Components.h"
  29. #include CMSIS_device_header
  30.  
  31. #ifdef  SysTick
  32.  
  33. #ifndef SYSTICK_IRQ_PRIORITY
  34. #define SYSTICK_IRQ_PRIORITY    0xFFU
  35. #endif
  36.  
  37. static uint8_t PendST;
  38.  
  39. // Setup OS Tick.
  40. __WEAK int32_t OS_Tick_Setup (uint32_t freq, IRQHandler_t handler) {
  41.   uint32_t load;
  42.   (void)handler;
  43.  
  44.   if (freq == 0U) {
  45.     //lint -e{904} "Return statement before end of function"
  46.     return (-1);
  47.   }
  48.  
  49.   load = (SystemCoreClock / freq) - 1U;
  50.   if (load > 0x00FFFFFFU) {
  51.     //lint -e{904} "Return statement before end of function"
  52.     return (-1);
  53.   }
  54.  
  55.   // Set SysTick Interrupt Priority
  56. #if   ((defined(__ARM_ARCH_8M_MAIN__) && (__ARM_ARCH_8M_MAIN__ != 0)) || \
  57.        (defined(__CORTEX_M)           && (__CORTEX_M           == 7U)))
  58.   SCB->SHPR[11] = SYSTICK_IRQ_PRIORITY;
  59. #elif  (defined(__ARM_ARCH_8M_BASE__) && (__ARM_ARCH_8M_BASE__ != 0))
  60.   SCB->SHPR[1] |= ((uint32_t)SYSTICK_IRQ_PRIORITY << 24);
  61. #elif ((defined(__ARM_ARCH_7M__)      && (__ARM_ARCH_7M__      != 0)) || \
  62.        (defined(__ARM_ARCH_7EM__)     && (__ARM_ARCH_7EM__     != 0)))
  63.   SCB->SHP[11]  = SYSTICK_IRQ_PRIORITY;
  64. #elif  (defined(__ARM_ARCH_6M__)      && (__ARM_ARCH_6M__      != 0))
  65.   SCB->SHP[1]  |= ((uint32_t)SYSTICK_IRQ_PRIORITY << 24);
  66. #else
  67. #error "Unknown ARM Core!"
  68. #endif
  69.  
  70.   SysTick->CTRL =  SysTick_CTRL_CLKSOURCE_Msk | SysTick_CTRL_TICKINT_Msk;
  71.   SysTick->LOAD =  load;
  72.   SysTick->VAL  =  0U;
  73.  
  74.   PendST = 0U;
  75.  
  76.   return (0);
  77. }
  78.  
  79. /// Enable OS Tick.
  80. __WEAK void OS_Tick_Enable (void) {
  81.  
  82.   if (PendST != 0U) {
  83.     PendST = 0U;
  84.     SCB->ICSR = SCB_ICSR_PENDSTSET_Msk;
  85.   }
  86.  
  87.   SysTick->CTRL |=  SysTick_CTRL_ENABLE_Msk;
  88. }
  89.  
  90. /// Disable OS Tick.
  91. __WEAK void OS_Tick_Disable (void) {
  92.  
  93.   SysTick->CTRL &= ~SysTick_CTRL_ENABLE_Msk;
  94.  
  95.   if ((SCB->ICSR & SCB_ICSR_PENDSTSET_Msk) != 0U) {
  96.     SCB->ICSR = SCB_ICSR_PENDSTCLR_Msk;
  97.     PendST = 1U;
  98.   }
  99. }
  100.  
  101. // Acknowledge OS Tick IRQ.
  102. __WEAK void OS_Tick_AcknowledgeIRQ (void) {
  103.   (void)SysTick->CTRL;
  104. }
  105.  
  106. // Get OS Tick IRQ number.
  107. __WEAK int32_t  OS_Tick_GetIRQn (void) {
  108.   return ((int32_t)SysTick_IRQn);
  109. }
  110.  
  111. // Get OS Tick clock.
  112. __WEAK uint32_t OS_Tick_GetClock (void) {
  113.   return (SystemCoreClock);
  114. }
  115.  
  116. // Get OS Tick interval.
  117. __WEAK uint32_t OS_Tick_GetInterval (void) {
  118.   return (SysTick->LOAD + 1U);
  119. }
  120.  
  121. // Get OS Tick count value.
  122. __WEAK uint32_t OS_Tick_GetCount (void) {
  123.   uint32_t load = SysTick->LOAD;
  124.   return  (load - SysTick->VAL);
  125. }
  126.  
  127. // Get OS Tick overflow status.
  128. __WEAK uint32_t OS_Tick_GetOverflow (void) {
  129.   return ((SysTick->CTRL >> 16) & 1U);
  130. }
  131.  
  132. #endif  // SysTick
  133.