flipperzero-firmware/firmware/targets/f7/furi_hal/furi_hal_delay.c

#include "furi_hal_delay.h"

#include <furi.h>
#include <cmsis_os2.h>
#include <stm32wbxx_ll_utils.h>

#define TAG "FuriHalDelay"

static volatile uint32_t tick_cnt = 0;

void furi_hal_delay_init() {
    CoreDebug->DEMCR |= CoreDebug_DEMCR_TRCENA_Msk;
    DWT->CTRL |= DWT_CTRL_CYCCNTENA_Msk;
    DWT->CYCCNT = 0U;
}

uint32_t furi_hal_delay_instructions_per_microsecond() {
    return SystemCoreClock / 1000000;
}

void furi_hal_tick(void) {
    tick_cnt++;
}

uint32_t furi_hal_get_tick(void) {
    return tick_cnt;
}

void furi_hal_delay_us(float microseconds) {
    uint32_t start = DWT->CYCCNT;
    uint32_t time_ticks = microseconds * furi_hal_delay_instructions_per_microsecond();
    while((DWT->CYCCNT - start) < time_ticks) {
    };
}

// cannot be used in ISR
// TODO add delay_ISR variant
void furi_hal_delay_ms(float milliseconds) {
    if(!FURI_IS_ISR() && osKernelGetState() == osKernelRunning) {
        uint32_t ticks = milliseconds / (1000.0f / osKernelGetTickFreq());
        osStatus_t result = osDelay(ticks);
        (void)result;
        furi_assert(result == osOK);
    } else {
        furi_hal_delay_us(milliseconds * 1000);
    }
}