circuitpython/ports/atmel-samd/shared_timers.c

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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 <stdint.h>
#include "samd/timers.h"
#include "shared_timers.h"
static uint8_t never_reset_tc_or_tcc[TC_INST_NUM + TCC_INST_NUM];
static void timer_refcount(int index, bool is_tc, int increment) {
if (is_tc) {
never_reset_tc_or_tcc[index] += increment;
} else {
never_reset_tc_or_tcc[TC_INST_NUM + index] += increment;
}
}
void timer_never_reset(int index, bool is_tc) {
timer_refcount(index, is_tc, 1);
}
void timer_reset_ok(int index, bool is_tc) {
timer_refcount(index, is_tc, -1);
}
bool timer_ok_to_reset(int index, bool is_tc) {
if (is_tc) {
return never_reset_tc_or_tcc[index] == 0;
}
return never_reset_tc_or_tcc[TC_INST_NUM + index] == 0;
}
void reset_timers(void) {
// Reset all timers
Tcc *tccs[TCC_INST_NUM] = TCC_INSTS;
for (int i = 0; i < TCC_INST_NUM; i++) {
if (!timer_ok_to_reset(i, false)) {
continue;
}
// Disable the module before resetting it.
if (tccs[i]->CTRLA.bit.ENABLE == 1) {
tccs[i]->CTRLA.bit.ENABLE = 0;
while (tccs[i]->SYNCBUSY.bit.ENABLE == 1) {
}
}
tccs[i]->CTRLA.bit.SWRST = 1;
while (tccs[i]->CTRLA.bit.SWRST == 1) {
}
}
Tc *tcs[TC_INST_NUM] = TC_INSTS;
for (int i = 0; i < TC_INST_NUM; i++) {
if (!timer_ok_to_reset(i, true)) {
continue;
}
tcs[i]->COUNT16.CTRLA.bit.SWRST = 1;
while (tcs[i]->COUNT16.CTRLA.bit.SWRST == 1) {
}
}
}