- /*
- Copyright 2012-2018 Jun Wako, Jack Humbert, Yiancar
-
- This program is free software: you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation, either version 2 of the License, or
- (at your option) any later version.
-
- This program is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
-
- You should have received a copy of the GNU General Public License
- along with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-
- #include <stdint.h>
- #include <stdbool.h>
- #include "matrix.h"
- #include "quantum.h"
- #include "sn74x138.h"
-
- static const pin_t row_pins[MATRIX_ROWS] = MATRIX_ROW_PINS;
- static const pin_t col_pins[MATRIX_COLS] = MATRIX_COL_PINS;
-
- /* Columns 6 and 9-15 use a 74HC138 3-to-8 demultiplexer.
- * D4 is the enable pin, must be set high to use it.
- *
- * 0: F7
- * 1: F5
- * 2: F6
- * 3: F1
- * 4: F4
- * 5: F0
- *
- * A2 A1 A0
- * D0 D1 D2
- * 6: 1 1 1
- *
- * 7: D5
- * 8: D3
- *
- * 9: 1 1 0
- * 10: 1 0 1
- * 11: 1 0 0
- * 12: 0 1 1
- * 13: 0 1 0
- * 14: 0 0 1
- * 15: 0 0 0
- */
- static void select_col(uint8_t col) {
- if (col_pins[col] != NO_PIN) {
- writePinLow(col_pins[col]);
- } else {
- sn74x138_set_addr((col == 6) ? 7 : 15 - col);
- sn74x138_set_enabled(true);
- }
- }
-
- static void unselect_col(uint8_t col) {
- if (col_pins[col] != NO_PIN) {
- setPinOutput(col_pins[col]);
- gpio_write_pin_high(col_pins[col]);
- } else {
- sn74x138_set_enabled(false);
- }
- }
-
- static void unselect_cols(void) {
- // Native
- for (uint8_t x = 0; x < MATRIX_COLS; x++) {
- if (col_pins[x] != NO_PIN) {
- setPinOutput(col_pins[x]);
- gpio_write_pin_high(col_pins[x]);
- }
- }
-
- // Demultiplexer
- sn74x138_set_enabled(false);
- }
-
- static void init_pins(void) {
- unselect_cols();
- for (uint8_t x = 0; x < MATRIX_ROWS; x++) {
- setPinInputHigh(row_pins[x]);
- }
- }
-
- static bool read_rows_on_col(matrix_row_t current_matrix[], uint8_t current_col) {
- bool matrix_changed = false;
-
- // Select col and wait for col selection to stabilize
- select_col(current_col);
- matrix_io_delay();
-
- // For each row...
- for (uint8_t row_index = 0; row_index < MATRIX_ROWS; row_index++) {
- // Store last value of row prior to reading
- matrix_row_t last_row_value = current_matrix[row_index];
-
- // Check row pin state
- if (gpio_read_pin(row_pins[row_index]) == 0) {
- // Pin LO, set col bit
- current_matrix[row_index] |= (MATRIX_ROW_SHIFTER << current_col);
- } else {
- // Pin HI, clear col bit
- current_matrix[row_index] &= ~(MATRIX_ROW_SHIFTER << current_col);
- }
-
- // Determine if the matrix changed state
- if ((last_row_value != current_matrix[row_index]) && !(matrix_changed)) {
- matrix_changed = true;
- }
- }
-
- // Unselect col
- unselect_col(current_col);
-
- return matrix_changed;
- }
-
- void matrix_init_custom(void) {
- // initialize demultiplexer
- sn74x138_init();
- // initialize key pins
- init_pins();
- }
-
- bool matrix_scan_custom(matrix_row_t current_matrix[]) {
- bool changed = false;
-
- // Set col, read rows
- for (uint8_t current_col = 0; current_col < MATRIX_COLS; current_col++) {
- changed |= read_rows_on_col(current_matrix, current_col);
- }
-
- return changed;
- }
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