circuitpython/ports/stm32/softtimer.c

113 lines
4.0 KiB
C

/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2019 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 <stdint.h>
#include "py/runtime.h"
#include "irq.h"
#include "softtimer.h"
#define TICKS_PERIOD 0x80000000
#define TICKS_DIFF(t1, t0) ((int32_t)(((t1 - t0 + TICKS_PERIOD / 2) & (TICKS_PERIOD - 1)) - TICKS_PERIOD / 2))
extern __IO uint32_t uwTick;
volatile uint32_t soft_timer_next;
void soft_timer_deinit(void) {
MP_STATE_PORT(soft_timer_head) = NULL;
}
STATIC void soft_timer_schedule_systick(uint32_t ticks_ms) {
uint32_t irq_state = disable_irq();
uint32_t uw_tick = uwTick;
if (TICKS_DIFF(ticks_ms, uw_tick) <= 0) {
soft_timer_next = uw_tick + 1;
} else {
soft_timer_next = ticks_ms;
}
enable_irq(irq_state);
}
// Must be executed at IRQ_PRI_PENDSV
void soft_timer_handler(void) {
uint32_t ticks_ms = uwTick;
soft_timer_entry_t *head = MP_STATE_PORT(soft_timer_head);
while (head != NULL && TICKS_DIFF(head->expiry_ms, ticks_ms) <= 0) {
mp_sched_schedule(head->callback, MP_OBJ_FROM_PTR(head));
if (head->mode == SOFT_TIMER_MODE_PERIODIC) {
head->expiry_ms += head->delta_ms;
// Shift this node along to its new position
soft_timer_entry_t *cur = head;
while (cur->next != NULL && TICKS_DIFF(head->expiry_ms, cur->next->expiry_ms) >= 0) {
cur = cur->next;
}
if (cur != head) {
soft_timer_entry_t *next = head->next;
head->next = cur->next;
cur->next = head;
head = next;
}
} else {
head = head->next;
}
}
MP_STATE_PORT(soft_timer_head) = head;
if (head == NULL) {
// No more timers left, set largest delay possible
soft_timer_next = uwTick;
} else {
// Set soft_timer_next so SysTick calls us back at the correct time
soft_timer_schedule_systick(head->expiry_ms);
}
}
void soft_timer_insert(soft_timer_entry_t *entry) {
uint32_t irq_state = raise_irq_pri(IRQ_PRI_PENDSV);
soft_timer_entry_t **head_ptr = &MP_STATE_PORT(soft_timer_head);
while (*head_ptr != NULL && TICKS_DIFF(entry->expiry_ms, (*head_ptr)->expiry_ms) >= 0) {
head_ptr = &(*head_ptr)->next;
}
entry->next = *head_ptr;
*head_ptr = entry;
if (head_ptr == &MP_STATE_PORT(soft_timer_head)) {
// This new timer became the earliest one so set soft_timer_next
soft_timer_schedule_systick((*head_ptr)->expiry_ms);
}
restore_irq_pri(irq_state);
}
void soft_timer_remove(soft_timer_entry_t *entry) {
uint32_t irq_state = raise_irq_pri(IRQ_PRI_PENDSV);
soft_timer_entry_t **cur = &MP_STATE_PORT(soft_timer_head);
while (*cur != NULL) {
if (*cur == entry) {
*cur = entry->next;
break;
}
}
restore_irq_pri(irq_state);
}