[Keyboard] add pierce (#17000)

Co-authored-by: Ryan <fauxpark@gmail.com>
Co-authored-by: Dan Abrahamsson <dan.abrahamsson@imsystech.com>

1 files changed, 43 insertions, 0 deletions

diff --git a/keyboards/pierce/matrix.c b/keyboards/pierce/matrix.c
new file mode 100644
index 0000000000..5023024b8b
--- /dev/null
+++ b/keyboards/pierce/matrix.c
@@ -0,0 +1,43 @@
+/* Copyright 2022 durken (https://github.com/durken1/)
+ *
+ * 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 "quantum.h"
+#include "i2c_slave.h"
+
+#define MY_I2C_ADDRESS (0x20U << 1)
+
+void matrix_init_custom(void) {
+    i2c_slave_init(MY_I2C_ADDRESS);
+}
+
+
+bool matrix_scan_custom(matrix_row_t current_matrix[]) {
+    bool matrix_has_changed = false;
+    matrix_row_t current_row_value;
+
+    for (uint8_t current_row = 0; current_row < MATRIX_ROWS; current_row++) {
+        current_row_value = 0; // Start with empty row
+        current_row_value |= (((matrix_row_t)(i2c_slave_reg[current_row+4])) << 5); // Add left half scan
+        current_row_value |= ((matrix_row_t)i2c_slave_reg[current_row]); // Add right half scan
+
+        if (current_matrix[current_row] != current_row_value) {
+            matrix_has_changed = true;
+        }
+        current_matrix[current_row] = current_row_value;
+    }
+
+    return matrix_has_changed;
+}