circuitpython/ports/mimxrt/systick.c

61 lines
2.4 KiB
C

/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2013, 2014 Damien P. George
*
* 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 "py/runtime.h"
#include "py/mphal.h"
#include "systick.h"
volatile uint32_t systick_ms = 0;
systick_dispatch_t systick_dispatch_table[SYSTICK_DISPATCH_NUM_SLOTS];
void SysTick_Handler(void) {
// Instead of calling HAL_IncTick we do the increment here of the counter.
// This is purely for efficiency, since SysTick is called 1000 times per
// second at the highest interrupt priority.
uint32_t uw_tick = systick_ms + 1;
systick_ms = uw_tick;
// Dispatch to any registered handlers in a cycle
systick_dispatch_t f = systick_dispatch_table[uw_tick & (SYSTICK_DISPATCH_NUM_SLOTS - 1)];
if (f != NULL) {
f(uw_tick);
}
}
bool systick_has_passed(uint32_t start_tick, uint32_t delay_ms) {
return systick_ms - start_tick >= delay_ms;
}
// waits until at least delay_ms milliseconds have passed from the sampling of
// startTick. Handles overflow properly. Assumes stc was taken from
// HAL_GetTick() some time before calling this function.
void systick_wait_at_least(uint32_t start_tick, uint32_t delay_ms) {
while (!systick_has_passed(start_tick, delay_ms)) {
__WFI(); // enter sleep mode, waiting for interrupt
}
}