Add support for the JJ40 Keyboard (#1834)

* Add support for JJ40

* Update readme

* Update maintaner

1 files changed, 106 insertions, 0 deletions

diff --git a/keyboards/jj40/matrix.c b/keyboards/jj40/matrix.c
new file mode 100644
index 0000000000..140026013f
--- /dev/null
+++ b/keyboards/jj40/matrix.c
@@ -0,0 +1,106 @@
+/*
+Copyright 2017 Luiz Ribeiro <luizribeiro@gmail.com>
+
+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 <avr/io.h>
+#include <util/delay.h>
+
+#include "matrix.h"
+
+#ifndef DEBOUNCE
+#   define DEBOUNCE	5
+#endif
+
+static uint8_t debouncing = DEBOUNCE;
+
+static matrix_row_t matrix[MATRIX_ROWS];
+static matrix_row_t matrix_debouncing[MATRIX_ROWS];
+
+void matrix_init(void) {
+    // all outputs for rows high
+    DDRB = 0xFF;
+    PORTB = 0xFF;
+    // all inputs for columns
+    DDRA = 0x00;
+    DDRC &= ~(0x111111<<2);
+    DDRD &= ~(1<<PIND7);
+    // all columns are pulled-up
+    PORTA = 0xFF;
+    PORTC |= (0b111111<<2);
+    PORTD |= (1<<PIND7);
+
+    // initialize matrix state: all keys off
+    for (uint8_t row = 0; row < MATRIX_ROWS; row++) {
+        matrix[row] = 0x00;
+        matrix_debouncing[row] = 0x00;
+    }
+}
+
+void matrix_set_row_status(uint8_t row) {
+    DDRB = (1 << row);
+    PORTB = ~(1 << row);
+}
+
+uint8_t bit_reverse(uint8_t x) {
+    x = ((x >> 1) & 0x55) | ((x << 1) & 0xaa);
+    x = ((x >> 2) & 0x33) | ((x << 2) & 0xcc);
+    x = ((x >> 4) & 0x0f) | ((x << 4) & 0xf0);
+    return x;
+}
+
+uint8_t matrix_scan(void) {
+    for (uint8_t row = 0; row < MATRIX_ROWS; row++) {
+        matrix_set_row_status(row);
+        _delay_us(5);
+
+        matrix_row_t cols = (
+            // cols 0..7, PORTA 0 -> 7
+            (~PINA) & 0xFF
+        ) | (
+            // cols 8..13, PORTC 7 -> 0
+            bit_reverse((~PINC) & 0xFF) << 8
+        ) | (
+            // col 14, PORTD 7
+            ((~PIND) & (1 << PIND7)) << 7
+        );
+
+        if (matrix_debouncing[row] != cols) {
+            matrix_debouncing[row] = cols;
+            debouncing = DEBOUNCE;
+        }
+    }
+
+    if (debouncing) {
+        if (--debouncing) {
+            _delay_ms(1);
+        } else {
+            for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
+                matrix[i] = matrix_debouncing[i];
+            }
+        }
+    }
+
+    matrix_scan_user();
+
+    return 1;
+}
+
+inline matrix_row_t matrix_get_row(uint8_t row) {
+    return matrix[row];
+}
+
+void matrix_print(void) {
+}