forked from forks/qmk_firmware
87 lines
2.8 KiB
C
87 lines
2.8 KiB
C
/* Copyright 2023 ebastler and elpekenin
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include "pca9555.h"
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#include "quantum.h"
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// PCA9555 i2c address, 0x20: A0 = 0, A1 = 0, A2 = 0
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#define IC1 0x20
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// Define how long to wait to reach the IO expander after connection loss again
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// Since this board is modular, it should not spam unnecessary i2c requests if used without a module
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#define RETRY_TIMESPAN 2000
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typedef enum {
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PLUGGED,
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DOUBTFUL,
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UNPLUGGED
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} expander_status_t;
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void pca9555_setup(void) {
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// Initialize the expander, no need to set ports to inputs as that is the default behavior
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pca9555_init(IC1);
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}
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void matrix_init_custom(void) {
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// Encoder pushbutton on the MCU is connected to PD2
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setPinInputHigh(D2);
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pca9555_setup();
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}
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bool matrix_scan_custom(matrix_row_t current_matrix[]) {
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static expander_status_t status = DOUBTFUL;
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static uint32_t retry_timer = 0;
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// initialize one byte filled with 1
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uint8_t pin_states = 0xFF;
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if (status != UNPLUGGED || timer_elapsed32(retry_timer) > RETRY_TIMESPAN) {
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// If the chip was unplugged before, it needs to be re-initialized
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if(status==UNPLUGGED) {
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pca9555_setup();
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}
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// Read the entire port into this byte, 1 = not pressed, 0 = pressed
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bool ret = pca9555_readPins(IC1, PCA9555_PORT0, &pin_states);
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// Update state
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if (ret) {
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status = PLUGGED;
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} else {
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switch (status) {
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case PLUGGED:
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status = DOUBTFUL;
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break;
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case DOUBTFUL:
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status = UNPLUGGED;
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break;
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// If we've diagnosed as unplugged, update timer to not read I2C
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case UNPLUGGED:
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retry_timer = timer_read32();
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}
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}
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}
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// Shift pin states by 1 to make room for the switch connected to the MCU, then OR them together and invert (as QMK uses inverted logic compared to the electrical levels)
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matrix_row_t data = ~(pin_states << 1 | readPin(D2));
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bool changed = current_matrix[0] != data;
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current_matrix[0] = data;
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return changed;
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} |