openblt/Target/Source/ARMCM4_S32K14/timer.c

111 lines
4.7 KiB
C

/************************************************************************************//**
* \file Source/ARMCM4_S32K14/timer.c
* \brief Bootloader timer driver source file.
* \ingroup Target_ARMCM4_S32K14
* \internal
*----------------------------------------------------------------------------------------
* C O P Y R I G H T
*----------------------------------------------------------------------------------------
* Copyright (c) 2020 by Feaser http://www.feaser.com All rights reserved
*
*----------------------------------------------------------------------------------------
* L I C E N S E
*----------------------------------------------------------------------------------------
* This file is part of OpenBLT. OpenBLT is free software: you can redistribute it and/or
* modify it under the terms of the GNU General Public License as published by the Free
* Software Foundation, either version 3 of the License, or (at your option) any later
* version.
*
* OpenBLT is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
* without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
* PURPOSE. See the GNU General Public License for more details.
*
* You have received a copy of the GNU General Public License along with OpenBLT. It
* should be located in ".\Doc\license.html". If not, contact Feaser to obtain a copy.
*
* \endinternal
****************************************************************************************/
/****************************************************************************************
* Include files
****************************************************************************************/
#include "boot.h" /* bootloader generic header */
#include "device_registers.h" /* device registers */
/****************************************************************************************
* Local data declarations
****************************************************************************************/
/** \brief Local variable for storing the number of milliseconds that have elapsed since
* startup.
*/
static blt_int32u millisecond_counter;
/************************************************************************************//**
** \brief Initializes the polling based millisecond timer driver.
** \return none.
**
****************************************************************************************/
void TimerInit(void)
{
/* Reset the timer configuration. */
TimerReset();
/* Configure the systick frequency as a 1 ms event generator. */
S32_SysTick->RVR = BOOT_CPU_SYSTEM_SPEED_KHZ - 1;
/* Reset the current counter value. */
S32_SysTick->CVR = 0u;
/* Select core clock as source and enable the timer. */
S32_SysTick->CSR = S32_SysTick_CSR_ENABLE_MASK | S32_SysTick_CSR_CLKSOURCE_MASK;
/* Reset the millisecond counter value. */
millisecond_counter = 0;
} /*** end of TimerInit ***/
/************************************************************************************//**
** \brief Reset the timer by placing the timer back into it's default reset
** configuration.
** \return none.
**
****************************************************************************************/
void TimerReset(void)
{
/* Set the systick's status and control register back into the default reset value. */
S32_SysTick->CSR = 0;
} /* end of TimerReset */
/************************************************************************************//**
** \brief Updates the millisecond timer.
** \return none.
**
****************************************************************************************/
void TimerUpdate(void)
{
/* Check if the millisecond event occurred. */
if ((S32_SysTick->CSR & S32_SysTick_CSR_COUNTFLAG_MASK) != 0)
{
/* Increment the millisecond counter. */
millisecond_counter++;
}
} /*** end of TimerUpdate ***/
/************************************************************************************//**
** \brief Obtains the counter value of the millisecond timer.
** \return Current value of the millisecond timer.
**
****************************************************************************************/
blt_int32u TimerGet(void)
{
/* Updating timer here allows this function to be called in a loop with timeout
* detection.
*/
TimerUpdate();
/* Read and return the amount of milliseconds that passed since initialization. */
return millisecond_counter;
} /*** end of TimerGet ***/
/*********************************** end of timer.c ************************************/