circuitpython/ports/esp32s2/common-hal/countio/Counter.c

/*
 * This file is part of the MicroPython project, http://micropython.org/
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2020 microDev
 *
 * 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 "common-hal/countio/Counter.h"
#include "common-hal/microcontroller/Pin.h"

void common_hal_countio_counter_construct(countio_counter_obj_t* self,
    const mcu_pin_obj_t* pin) {
    claim_pin(pin);

    // Prepare configuration for the PCNT unit
    pcnt_config_t pcnt_config = {
        // Set PCNT input signal and control GPIOs
        .pulse_gpio_num = pin->number,
        .ctrl_gpio_num = PCNT_PIN_NOT_USED,
        .channel = PCNT_CHANNEL_0,
        // What to do on the positive / negative edge of pulse input?
        .pos_mode = PCNT_COUNT_INC,   // Count up on the positive edge
        .neg_mode = PCNT_COUNT_DIS,   // Keep the counter value on the negative edge
    };
    // Initialize PCNT unit
    // This also sets pcnt_config.unit
    peripherals_pcnt_init(&pcnt_config);

    self->pin = pin->number;
    self->unit = pcnt_config.unit;
}

bool common_hal_countio_counter_deinited(countio_counter_obj_t* self) {
    return self->unit == PCNT_UNIT_MAX;
}

void common_hal_countio_counter_deinit(countio_counter_obj_t* self) {
    if (common_hal_countio_counter_deinited(self)) {
        return;
    }
    reset_pin_number(self->pin);
    peripherals_pcnt_deinit(&self->unit);
}

mp_int_t common_hal_countio_counter_get_count(countio_counter_obj_t* self) {
    int16_t count;
    pcnt_get_counter_value(self->unit, &count);
    return count+self->count;
}

void common_hal_countio_counter_set_count(countio_counter_obj_t* self,
        mp_int_t new_count) {
    self->count = new_count;
    pcnt_counter_clear(self->unit);
}

void common_hal_countio_counter_reset(countio_counter_obj_t* self) {
   common_hal_countio_counter_set_count(self, 0);
}