tbm-mcu/source/platform/stm32f1/alarm.c

#include <libopencm3/cm3/nvic.h>
#include <libopencm3/stm32/exti.h>
#include <libopencm3/stm32/gpio.h>
#include <libopencm3/stm32/rtc.h>

#include <rtc.h>

static int reset = 0;

void rtc_alarm_isr(void)
{
	if (rtc_check_flag(RTC_ALR)) {
		rtc_clear_flag(RTC_ALR);

		rtc_disable_alarm();
		exti_reset_request(EXTI17);

		if (!reset) {
			reset = 1;
			gpio_set(GPIOA, GPIO1);

			rtc_set_alarm_time(rtc_get_counter_val() + 5);
			rtc_enable_alarm();
		} else {
			reset = 0;
			gpio_set(GPIOA, GPIO1);
			alarm_disable();
		}
	}
}

int alarm_enable(uint32_t timeout)
{
	rtc_enable_alarm();
	rtc_set_alarm_time(rtc_get_counter_val() + timeout);

	exti_enable_request(EXTI17);
	exti_set_trigger(EXTI17, EXTI_TRIGGER_RISING);

	nvic_enable_irq(NVIC_RTC_ALARM_IRQ);
	nvic_set_priority(NVIC_RTC_ALARM_IRQ, 1);

	rtc_interrupt_enable(RTC_ALR);

	return 0;
}

int alarm_disable(void)
{
	exti_disable_request(EXTI17);
	nvic_disable_irq(NVIC_RTC_ALARM_IRQ);
	rtc_interrupt_disable(RTC_ALR);
	rtc_disable_alarm();

	return 0;
}