151 lines
4.0 KiB
C
151 lines
4.0 KiB
C
/* Copyright 2020 sekigon-gonnoc
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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 "ec_switch_matrix.h"
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#include <avr/interrupt.h>
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#include "analog.h"
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#include "print.h"
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// pin connections
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const uint8_t row_pins[] = MATRIX_ROW_PINS;
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const uint8_t col_channels[] = MATRIX_COL_CHANNELS;
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const uint8_t mux_sel_pins[] = MUX_SEL_PINS;
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_Static_assert(sizeof(mux_sel_pins) == 3, "invalid MUX_SEL_PINS");
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static ecsm_config_t config;
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static uint16_t ecsm_sw_value[MATRIX_ROWS][MATRIX_COLS];
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static inline void discharge_capacitor(void) { gpio_set_pin_output(DISCHARGE_PIN); }
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static inline void charge_capacitor(uint8_t row) {
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gpio_set_pin_input(DISCHARGE_PIN);
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gpio_write_pin_high(row_pins[row]);
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}
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static inline void clear_all_row_pins(void) {
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for (int row = 0; row < sizeof(row_pins); row++) {
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gpio_write_pin_low(row_pins[row]);
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}
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}
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static inline void init_mux_sel(void) {
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for (int idx = 0; idx < sizeof(mux_sel_pins); idx++) {
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gpio_set_pin_output(mux_sel_pins[idx]);
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}
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}
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static inline void select_mux(uint8_t col) {
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uint8_t ch = col_channels[col];
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gpio_write_pin(mux_sel_pins[0], ch & 1);
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gpio_write_pin(mux_sel_pins[1], ch & 2);
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gpio_write_pin(mux_sel_pins[2], ch & 4);
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}
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static inline void init_row(void) {
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for (int idx = 0; idx < sizeof(row_pins); idx++) {
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gpio_set_pin_output(row_pins[idx]);
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gpio_write_pin_low(row_pins[idx]);
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}
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}
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// Initialize pins
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int ecsm_init(ecsm_config_t const* const ecsm_config) {
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// save config
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config = *ecsm_config;
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// initialize discharge pin as discharge mode
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gpio_write_pin_low(DISCHARGE_PIN);
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gpio_set_pin_output(DISCHARGE_PIN);
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// set analog reference
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analogReference(ADC_REF_POWER);
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// initialize drive lines
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init_row();
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// initialize multiplexer select pin
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init_mux_sel();
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// set discharge pin to charge mode
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gpio_set_pin_input(DISCHARGE_PIN);
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return 0;
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}
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// Read key value of key (row, col)
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uint16_t ecsm_readkey_raw(uint8_t row, uint8_t col) {
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uint16_t sw_value = 0;
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discharge_capacitor();
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select_mux(col);
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clear_all_row_pins();
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cli();
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charge_capacitor(row);
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sw_value = analogReadPin(ANALOG_PORT);
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sei();
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return sw_value;
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}
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// Update press/release state of key at (row, col)
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bool ecsm_update_key(matrix_row_t* current_row, uint8_t col, uint16_t sw_value) {
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bool current_state = (*current_row >> col) & 1;
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// press to release
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if (current_state && sw_value < config.low_threshold) {
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*current_row &= ~(1 << col);
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return true;
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}
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// release to press
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if ((!current_state) && sw_value > config.high_threshold) {
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*current_row |= (1 << col);
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return true;
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}
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return false;
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}
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// Scan key values and update matrix state
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bool ecsm_matrix_scan(matrix_row_t current_matrix[]) {
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bool updated = false;
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for (int col = 0; col < sizeof(col_channels); col++) {
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for (int row = 0; row < sizeof(row_pins); row++) {
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ecsm_sw_value[row][col] = ecsm_readkey_raw(row, col);
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updated |= ecsm_update_key(¤t_matrix[row], col, ecsm_sw_value[row][col]);
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}
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}
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return updated;
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}
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// Print key values
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void ecsm_print_matrix(void) {
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for (int row = 0; row < sizeof(row_pins); row++) {
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for (int col = 0; col < sizeof(col_channels); col++) {
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xprintf("%4d", ecsm_sw_value[row][col]);
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}
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xprintf("\n");
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}
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}
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