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// This file is part of the CircuitPython project: https://circuitpython.org

//

// SPDX-FileCopyrightText: Copyright (c) 2021 Dan Halbert for Adafruit Industries

//

// SPDX-License-Identifier: MIT

#include <string.h>

#include "py/gc.h"

#include "py/mphal.h"

#include "py/runtime.h"

#include "shared-bindings/digitalio/DigitalInOut.h"

#include "shared-bindings/keypad/EventQueue.h"

#include "shared-bindings/keypad/KeyMatrix.h"

#include "shared-bindings/keypad/__init__.h"

#include "shared-bindings/supervisor/__init__.h"

#include "shared-bindings/util.h"

#include "supervisor/port.h"

#include "supervisor/shared/tick.h"

static void keymatrix_scan_now(void *self_in, mp_obj_t timestamp);

static size_t keymatrix_get_key_count(void *self_in);

static keypad_scanner_funcs_t keymatrix_funcs = {

.scan_now = keymatrix_scan_now,

.get_key_count = keymatrix_get_key_count,

};

static mp_uint_t row_column_to_key_number(keypad_keymatrix_obj_t *self, mp_uint_t row, mp_uint_t column) {

return row * self->column_digitalinouts->len + column;

}

void common_hal_keypad_keymatrix_construct(keypad_keymatrix_obj_t *self, mp_uint_t num_row_pins, const mcu_pin_obj_t *row_pins[], mp_uint_t num_column_pins, const mcu_pin_obj_t *column_pins[], bool columns_to_anodes, mp_float_t interval, size_t max_events, uint8_t debounce_threshold) {

mp_obj_t row_dios[num_row_pins];

for (size_t row = 0; row < num_row_pins; row++) {

digitalio_digitalinout_obj_t *dio =

mp_obj_malloc(digitalio_digitalinout_obj_t, &digitalio_digitalinout_type);

common_hal_digitalio_digitalinout_construct(dio, row_pins[row]);

common_hal_digitalio_digitalinout_switch_to_input(dio, columns_to_anodes ? PULL_UP : PULL_DOWN);

row_dios[row] = dio;

}

self->row_digitalinouts = mp_obj_new_tuple(num_row_pins, row_dios);

mp_obj_t column_dios[num_column_pins];

for (size_t column = 0; column < num_column_pins; column++) {

digitalio_digitalinout_obj_t *dio =

mp_obj_malloc(digitalio_digitalinout_obj_t, &digitalio_digitalinout_type);

dio->base.type = &digitalio_digitalinout_type;

common_hal_digitalio_digitalinout_construct(dio, column_pins[column]);

common_hal_digitalio_digitalinout_switch_to_input(dio, columns_to_anodes ? PULL_UP : PULL_DOWN);

column_dios[column] = dio;

}

self->column_digitalinouts = mp_obj_new_tuple(num_column_pins, column_dios);

self->columns_to_anodes = columns_to_anodes;

self->funcs = &keymatrix_funcs;

keypad_construct_common((keypad_scanner_obj_t *)self, interval, max_events, debounce_threshold);

}

void common_hal_keypad_keymatrix_deinit(keypad_keymatrix_obj_t *self) {

if (common_hal_keypad_deinited(self)) {

return;

}

// Remove self from the list of active keypad scanners first.

keypad_deregister_scanner((keypad_scanner_obj_t *)self);

for (size_t row = 0; row < common_hal_keypad_keymatrix_get_row_count(self); row++) {

common_hal_digitalio_digitalinout_deinit(self->row_digitalinouts->items[row]);

}

self->row_digitalinouts = MP_ROM_NONE;

for (size_t column = 0; column < common_hal_keypad_keymatrix_get_column_count(self); column++) {

common_hal_digitalio_digitalinout_deinit(self->column_digitalinouts->items[column]);

}

self->column_digitalinouts = MP_ROM_NONE;

common_hal_keypad_deinit_core(self);

}

size_t common_hal_keypad_keymatrix_get_row_count(keypad_keymatrix_obj_t *self) {

return self->row_digitalinouts->len;

}

size_t common_hal_keypad_keymatrix_get_column_count(keypad_keymatrix_obj_t *self) {

return self->column_digitalinouts->len;

}

mp_uint_t common_hal_keypad_keymatrix_row_column_to_key_number(keypad_keymatrix_obj_t *self, mp_uint_t row, mp_uint_t column) {

return row_column_to_key_number(self, row, column);

}

void common_hal_keypad_keymatrix_key_number_to_row_column(keypad_keymatrix_obj_t *self, mp_uint_t key_number, mp_uint_t *row, mp_uint_t *column) {

const size_t num_columns = common_hal_keypad_keymatrix_get_column_count(self);

*row = key_number / num_columns;

*column = key_number % num_columns;

}

static size_t keymatrix_get_key_count(void *self_in) {

keypad_keymatrix_obj_t *self = self_in;

return common_hal_keypad_keymatrix_get_column_count(self) * common_hal_keypad_keymatrix_get_row_count(self);

}

static void keymatrix_scan_now(void *self_in, mp_obj_t timestamp) {

keypad_keymatrix_obj_t *self = self_in;

// On entry, all pins are set to inputs with a pull-up or pull-down,

// depending on the diode orientation.

for (size_t row = 0; row < common_hal_keypad_keymatrix_get_row_count(self); row++) {

// Switch this row to an output and set level appropriately

// Set low if columns_to_anodes is true, else set high.

digitalio_digitalinout_obj_t *row_dio = self->row_digitalinouts->items[row];

common_hal_digitalio_digitalinout_switch_to_output(

row_dio, !self->columns_to_anodes, DRIVE_MODE_PUSH_PULL);

for (size_t column = 0; column < common_hal_keypad_keymatrix_get_column_count(self); column++) {

mp_uint_t key_number = row_column_to_key_number(self, row, column);

// Get the current state, by reading whether the column got pulled to the row value or not.

// If low and columns_to_anodes is true, the key is pressed.

// If high and columns_to_anodes is false, the key is pressed.

const bool current =

common_hal_digitalio_digitalinout_get_value(self->column_digitalinouts->items[column]) !=

self->columns_to_anodes;

// Record any transitions.

if (keypad_debounce((keypad_scanner_obj_t *)self, key_number, current)) {

keypad_eventqueue_record(self->events, key_number, current, timestamp);

}

}

// Done with this row. Set its pin to its resting pull value briefly to shorten the time it takes

// to switch values. Just switching to an input with a (relatively weak) pullup/pulldown

// causes a slight delay in the output changing, which can cause false readings.

common_hal_digitalio_digitalinout_set_value(row_dio, self->columns_to_anodes);

// Wait a moment to let the columns settle.

mp_hal_delay_us(1);

// Switch the row back to an input, pulled appropriately

common_hal_digitalio_digitalinout_switch_to_input(

row_dio, self->columns_to_anodes ? PULL_UP : PULL_DOWN);

}

}