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/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2017 Scott Shawcroft for Adafruit Industries
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "tick.h"
#include "supervisor/shared/autoreload.h"
#include "supervisor/filesystem.h"
#include "shared-module/gamepad/__init__.h"
#include "shared-bindings/microcontroller/Processor.h"
#include "stm32f4xx.h"
// Global millisecond tick count
volatile uint64_t ticks_ms = 0;
void SysTick_Handler(void) {
// SysTick interrupt handler called when the SysTick timer reaches zero
// (every millisecond).
ticks_ms += 1;
#if CIRCUITPY_FILESYSTEM_FLUSH_INTERVAL_MS > 0
filesystem_tick();
#endif
#ifdef CIRCUITPY_AUTORELOAD_DELAY_MS
autoreload_tick();
#endif
#ifdef CIRCUITPY_GAMEPAD_TICKS
if (!(ticks_ms & CIRCUITPY_GAMEPAD_TICKS)) {
gamepad_tick();
}
#endif
}
void tick_init() {
uint32_t ticks_per_ms = SystemCoreClock/ 1000;
SysTick_Config(ticks_per_ms); // interrupt is enabled
}
void tick_delay(uint32_t us) {
uint32_t ticks_per_us = SystemCoreClock / 1000 / 1000;
uint32_t us_between_ticks = SysTick->VAL / ticks_per_us;
uint64_t start_ms = ticks_ms;
while (us > 1000) {
while (ticks_ms == start_ms) {}
us -= us_between_ticks;
start_ms = ticks_ms;
us_between_ticks = 1000;
}
while (SysTick->VAL > ((us_between_ticks - us) * ticks_per_us)) {}
}
// us counts down!
void current_tick(uint64_t* ms, uint32_t* us_until_ms) {
uint32_t ticks_per_us = SystemCoreClock / 1000 / 1000;
*ms = ticks_ms;
*us_until_ms = SysTick->VAL / ticks_per_us;
}
void wait_until(uint64_t ms, uint32_t us_until_ms) {
uint32_t ticks_per_us = SystemCoreClock / 1000 / 1000;
while(ticks_ms <= ms && SysTick->VAL / ticks_per_us >= us_until_ms) {}
}
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