circuitpython/ports/raspberrypi/common-hal/digitalio/DigitalInOut.c

/*
 * This file is part of the MicroPython project, http://micropython.org/
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2020 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 <string.h>

#include "py/runtime.h"
#include "py/mphal.h"

#include "common-hal/microcontroller/Pin.h"
#include "shared-bindings/digitalio/DigitalInOut.h"
#include "supervisor/shared/translate.h"

#include "src/rp2_common/hardware_gpio/include/hardware/gpio.h"

digitalinout_result_t common_hal_digitalio_digitalinout_construct(
        digitalio_digitalinout_obj_t* self, const mcu_pin_obj_t* pin) {
    claim_pin(pin);
    self->pin = pin;
    self->output = false;
    self->open_drain = false;

    // Set to input. No output value.
    gpio_init(pin->number);
    return DIGITALINOUT_OK;
}

void common_hal_digitalio_digitalinout_never_reset(
        digitalio_digitalinout_obj_t *self) {
    never_reset_pin_number(self->pin->number);
}

bool common_hal_digitalio_digitalinout_deinited(digitalio_digitalinout_obj_t* self) {
    return self->pin == NULL;
}

void common_hal_digitalio_digitalinout_deinit(digitalio_digitalinout_obj_t* self) {
    if (common_hal_digitalio_digitalinout_deinited(self)) {
        return;
    }
    reset_pin_number(self->pin->number);
    self->pin = NULL;
}

void common_hal_digitalio_digitalinout_switch_to_input(
        digitalio_digitalinout_obj_t* self, digitalio_pull_t pull) {
    self->output = false;
    // This also sets direction to input.
    common_hal_digitalio_digitalinout_set_pull(self, pull);
}

digitalinout_result_t common_hal_digitalio_digitalinout_switch_to_output(
        digitalio_digitalinout_obj_t* self, bool value,
        digitalio_drive_mode_t drive_mode) {
    const uint8_t pin = self->pin->number;
    gpio_disable_pulls(pin);

    // Turn on "strong" pin driving (more current available).
    hw_write_masked(&padsbank0_hw->io[pin],
                    PADS_BANK0_GPIO0_DRIVE_VALUE_12MA << PADS_BANK0_GPIO0_DRIVE_LSB,
                    PADS_BANK0_GPIO0_DRIVE_BITS);

    self->output = true;
    self->open_drain = drive_mode == DRIVE_MODE_OPEN_DRAIN;

    // Pin direction is ultimately set in set_value. We don't need to do it here.
    common_hal_digitalio_digitalinout_set_value(self, value);
    return DIGITALINOUT_OK;
}

digitalio_direction_t common_hal_digitalio_digitalinout_get_direction(
        digitalio_digitalinout_obj_t* self) {
    return self->output ? DIRECTION_OUTPUT : DIRECTION_INPUT;
}

void common_hal_digitalio_digitalinout_set_value(
        digitalio_digitalinout_obj_t* self, bool value) {
    const uint8_t pin = self->pin->number;
    if (value) {
        // If true, set the direction -before- setting the pin value, to
        // to avoid a glitch true 3.3v on the pin before switching from output to input for open drain.
        if (self->open_drain) {
            gpio_set_dir(pin, GPIO_IN);
        }
        gpio_put(pin, true);
    } else {
        // If false, set the direction -after- setting the pin value,
        // to avoid a glitch 3.3v on the pin before switching from input to output for open drain,
        // when previous value was high.
        gpio_put(pin, false);
        if (self->open_drain) {
            gpio_set_dir(pin, GPIO_OUT);
        }
    }
}

bool common_hal_digitalio_digitalinout_get_value(
        digitalio_digitalinout_obj_t* self) {
    return gpio_get(self->pin->number);
}

digitalinout_result_t common_hal_digitalio_digitalinout_set_drive_mode(
        digitalio_digitalinout_obj_t* self,
        digitalio_drive_mode_t drive_mode) {
    const uint8_t pin = self->pin->number;
    bool value = common_hal_digitalio_digitalinout_get_value(self);
    self->open_drain = drive_mode == DRIVE_MODE_OPEN_DRAIN;
    // True is implemented differently between modes so reset the value to make
    // sure it's correct for the new mode.
    if (value) {
        common_hal_digitalio_digitalinout_set_value(self, value);
    }
    return DIGITALINOUT_OK;
}

digitalio_drive_mode_t common_hal_digitalio_digitalinout_get_drive_mode(
        digitalio_digitalinout_obj_t* self) {
    if (self->open_drain) {
        return DRIVE_MODE_OPEN_DRAIN;
    } else {
        return DRIVE_MODE_PUSH_PULL;
    }
}

void common_hal_digitalio_digitalinout_set_pull(
        digitalio_digitalinout_obj_t* self, digitalio_pull_t pull) {
    const uint8_t pin = self->pin->number;
    gpio_set_pulls(pin, pull == PULL_UP, pull == PULL_DOWN);
    gpio_set_dir(pin, GPIO_IN);
}

digitalio_pull_t common_hal_digitalio_digitalinout_get_pull(
        digitalio_digitalinout_obj_t* self) {
    uint32_t pin = self->pin->number;
    if (self->output) {
        mp_raise_AttributeError(translate("Cannot get pull while in output mode"));
        return PULL_NONE;
    } else {
        if (gpio_is_pulled_up(pin)) {
            return PULL_UP;
        } else if (gpio_is_pulled_down(pin)) {
            return PULL_DOWN;
        }
    }
    return PULL_NONE;
}