/* Reflow Oven Controller
 *
 * Copyright (C) 2020  Mario Hüttel <mario.huettel@gmx.net>
 *
 * This file is part of the Reflow Oven Controller Project.
 *
 * The reflow oven controller is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * The Reflow Oven Control Firmware 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 the reflow oven controller project.
 * If not, see <http://www.gnu.org/licenses/>.
 */

/**
 * @file systick.c
 */

#include <reflow-controller/systick.h>
#include <stm32/stm32f4xx.h>
#include <cmsis/core_cm4.h>

volatile uint32_t wait_tick_ms = 0UL;
volatile uint64_t global_tick_ms = 0ULL;
volatile uint32_t lcd_tick_ms = 0UL;

void systick_setup(void)
{
	/* Setup Systick for 1ms tick @ 168 MHz Clock Speed */
	SysTick_Config(SYSTICK_RELOAD);
}

void systick_wait_ms(uint32_t ms)
{
	wait_tick_ms = 0UL;
	while (wait_tick_ms < ms);
}

uint64_t systick_get_global_tick()
{
	uint64_t temp;

	__disable_irq();
	temp = global_tick_ms;
	__enable_irq();

	return temp;
}

bool __attribute__((optimize("O3"))) systick_ticks_have_passed(uint64_t start_timestamp, uint64_t ticks)
{
	uint64_t end_timestamp = start_timestamp + ticks;
	uint64_t current_timestamp = systick_get_global_tick();

	/* wrap around expected */
	if (end_timestamp < start_timestamp) {
		/* Wrap around occured */
		if (current_timestamp < start_timestamp) {
			if (current_timestamp >= end_timestamp)
				return true;
		}
	} else {
		if (current_timestamp >= end_timestamp)
			return true;
	}

	return false;
}

/**
 * @brief Interrupt Handler for SysTick
 *
 * This handler is called every millisecond
 *
 * @warning For calling cyclic functions use separate timers/flags and don't spoil this function
 */
void __attribute__((optimize("O3"))) SysTick_Handler()
{
	/* Increase tick counters */
	wait_tick_ms++;
	global_tick_ms++;
	lcd_tick_ms++;
}