pinebuds/rtos/rtx5/os_systick.c

/**************************************************************************/ /**
                                                                              * @file     os_systick.c
                                                                              * @brief    CMSIS OS Tick SysTick implementation
                                                                              * @version  V1.0.1
                                                                              * @date     24. November 2017
                                                                              ******************************************************************************/
/*
 * Copyright (c) 2017-2017 ARM Limited. All rights reserved.
 *
 * 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.
 */
#include "hal_timer.h"

#include "os_tick.h"

// lint -emacro((923,9078),SCB,SysTick) "cast from unsigned long to pointer"
#include "RTE_Components.h"
#include CMSIS_device_header

#ifdef SysTick

#ifndef SYSTICK_IRQ_PRIORITY
#define SYSTICK_IRQ_PRIORITY 0xFFU
#endif

#ifdef CALIB_SLOW_TIMER
#define OS_CLOCK                                                               \
  (CONFIG_SYSTICK_HZ * (OS_CLOCK_NOMINAL / CONFIG_SYSTICK_HZ_NOMINAL))
#else
#define OS_CLOCK OS_CLOCK_NOMINAL
#endif

uint32_t SystemCoreClock;

#define SYSTICK_EXTERNAL_CLOCK 1

void SystemCoreClockUpdate() { SystemCoreClock = OS_CLOCK; }

static uint8_t PendST;
// Setup OS Tick.
__WEAK int32_t OS_Tick_Setup(uint32_t freq, IRQHandler_t handler) {
  uint32_t load;
  (void)handler;

  if (freq == 0U) {
    // lint -e{904} "Return statement before end of function"
    return (-1);
  }

  load = (SystemCoreClock / freq) - 1U;
  if (load > 0x00FFFFFFU) {
    // lint -e{904} "Return statement before end of function"
    return (-1);
  }

  // Set SysTick Interrupt Priority
#if ((defined(__ARM_ARCH_8M_MAIN__) && (__ARM_ARCH_8M_MAIN__ != 0)) ||         \
     (defined(__CORTEX_M) && (__CORTEX_M == 7U)))
  SCB->SHPR[11] = SYSTICK_IRQ_PRIORITY;
#elif (defined(__ARM_ARCH_8M_BASE__) && (__ARM_ARCH_8M_BASE__ != 0))
  SCB->SHPR[1] |= ((uint32_t)SYSTICK_IRQ_PRIORITY << 24);
#elif ((defined(__ARM_ARCH_7M__) && (__ARM_ARCH_7M__ != 0)) ||                 \
       (defined(__ARM_ARCH_7EM__) && (__ARM_ARCH_7EM__ != 0)))
  SCB->SHP[11] = SYSTICK_IRQ_PRIORITY;
#elif (defined(__ARM_ARCH_6M__) && (__ARM_ARCH_6M__ != 0))
  SCB->SHP[1] |= ((uint32_t)SYSTICK_IRQ_PRIORITY << 24);
#else
#error "Unknown ARM Core!"
#endif

#if (SYSTICK_EXTERNAL_CLOCK)
  SysTick->CTRL = SysTick_CTRL_TICKINT_Msk;
#else
  SysTick->CTRL = SysTick_CTRL_CLKSOURCE_Msk | SysTick_CTRL_TICKINT_Msk;
#endif
  SysTick->LOAD = load;
  SysTick->VAL = 0U;

  PendST = 0U;

  return (0);
}

/// Enable OS Tick.
__WEAK void OS_Tick_Enable(void) {

  if (PendST != 0U) {
    PendST = 0U;
    SCB->ICSR = SCB_ICSR_PENDSTSET_Msk;
  }

  SysTick->CTRL |= SysTick_CTRL_ENABLE_Msk;
}

/// Disable OS Tick.
__WEAK void OS_Tick_Disable(void) {

  SysTick->CTRL &= ~SysTick_CTRL_ENABLE_Msk;

  if ((SCB->ICSR & SCB_ICSR_PENDSTSET_Msk) != 0U) {
    SCB->ICSR = SCB_ICSR_PENDSTCLR_Msk;
    PendST = 1U;
  }
}

// Acknowledge OS Tick IRQ.
__WEAK void OS_Tick_AcknowledgeIRQ(void) { (void)SysTick->CTRL; }

// Get OS Tick IRQ number.
__WEAK int32_t OS_Tick_GetIRQn(void) { return ((int32_t)SysTick_IRQn); }

// Get OS Tick clock.
__WEAK uint32_t OS_Tick_GetClock(void) { return (SystemCoreClock); }

// Get OS Tick interval.
__WEAK uint32_t OS_Tick_GetInterval(void) { return (SysTick->LOAD + 1U); }

// Get OS Tick count value.
__WEAK uint32_t OS_Tick_GetCount(void) {
  uint32_t load = SysTick->LOAD;
  return (load - SysTick->VAL);
}

// Get OS Tick overflow status.
__WEAK uint32_t OS_Tick_GetOverflow(void) {
  return ((SysTick->CTRL >> 16) & 1U);
}

#endif // SysTick