OpenRTX/platform/mcu/STM32F4xx/drivers/delays.cpp

/***************************************************************************
 *   Copyright (C) 2020 - 2022 by Silvano Seva IU2KWO                      *
 *                            and Niccolò Izzo IU2KIN                      *
 *                                                                         *
 *   This program 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.                                   *
 *                                                                         *
 *   This program 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 should have received a copy of the GNU General Public License     *
 *   along with this program; if not, see <http://www.gnu.org/licenses/>   *
 ***************************************************************************/

#include <interfaces/delays.h>
#include <miosix.h>

/**
 * Implementation of the delay functions for STM32F405 MCU.
 */

void delayUs(unsigned int useconds)
{
    // This delay has been calibrated to take x microseconds
    // It is written in assembler to be independent on compiler optimization
    asm volatile("           mov   r1, #42    \n"
                 "           mul   r2, %0, r1 \n"
                 "           mov   r1, #0     \n"
                 "___loop_u: cmp   r1, r2     \n"
                 "           itt   lo         \n"
                 "           addlo r1, r1, #1 \n"
                 "           blo   ___loop_u  \n"::"r"(useconds):"r1","r2");
}

void delayMs(unsigned int mseconds)
{
    register const unsigned int count=42000;

    for(unsigned int i=0;i<mseconds;i++)
    {
        // This delay has been calibrated to take 1 millisecond
        // It is written in assembler to be independent on compiler optimization
        asm volatile("           mov   r1, #0     \n"
                     "___loop_m: cmp   r1, %0     \n"
                     "           itt   lo         \n"
                     "           addlo r1, r1, #1 \n"
                     "           blo   ___loop_m  \n"::"r"(count):"r1");
    }
}

void sleepFor(unsigned int seconds, unsigned int mseconds)
{
    unsigned int time = (seconds * 1000) + mseconds;
    miosix::Thread::sleep(time);
}

void sleepUntil(long long timestamp)
{
    miosix::Thread::sleepUntil(timestamp);
}

long long getTick()
{
    return miosix::getTick();
}