1 files changed, 93 insertions, 0 deletions
diff --git a/keyboards/matrix/m20add/matrix.c b/keyboards/matrix/m20add/matrix.c
new file mode 100644
index 0000000000..b17643fea8
--- /dev/null
+++ b/keyboards/matrix/m20add/matrix.c
@@ -0,0 +1,93 @@
+/**
+ * matrix.c
+ */
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <string.h>
+#include "quantum.h"
+#include "matrix.h"
+#include "tca6424.h"
+#include "m20add.h"
+
+static const uint16_t col_pins[MATRIX_COLS] = MATRIX_COL_PINS;
+
+void matrix_init_custom(void)
+{
+    tca6424_init();
+    // set port0
+    tca6424_write_config(TCA6424_PORT0, 0);
+    // set port1
+    tca6424_write_config(TCA6424_PORT1, 0);
+    // set port2
+    tca6424_write_config(TCA6424_PORT2, 0xF5);
+
+    // clear output
+    tca6424_write_port(TCA6424_PORT0, 0);
+    tca6424_write_port(TCA6424_PORT1, 0);
+    tca6424_write_port(TCA6424_PORT2, 0);
+}
+
+
+static uint8_t row_mask[] = {ROW1_MASK,ROW2_MASK,ROW3_MASK,ROW4_MASK,ROW5_MASK,ROW6_MASK};
+static uint8_t col_mask[] = {COL1_MASK, COL2_MASK, COL3_MASK, COL4_MASK, COL5_MASK, COL6_MASK, COL7_MASK, COL8_MASK, COL9_MASK, COL10_MASK, COL11_MASK, COL12_MASK, COL13_MASK, COL14_MASK, COL15_MASK, COL16_MASK};
+
+bool matrix_scan_custom(matrix_row_t current_matrix[])
+{
+    bool changed = false;
+    uint8_t p0_data = tca6424_read_port(TCA6424_PORT0);
+
+    for (int col = 0; col < MATRIX_COLS; col++) {
+        // Select col and wait for col selecton to stabilize
+        switch(col) {
+        case 0:
+            set_pin(col_pins[col]);
+            break;
+        case 1 ... 8:
+            tca6424_write_port(TCA6424_PORT1, col_mask[col]);
+            break;
+        default:
+            tca6424_write_port(TCA6424_PORT0, col_mask[col]|(p0_data&0x01));
+            break;
+        }
+        matrix_io_delay();
+
+        // read row port for all rows
+        uint8_t row_value = tca6424_read_port(ROW_PORT);
+        for (uint8_t row = 0; row < MATRIX_ROWS; row++) {
+            uint8_t tmp = row;
+            // Store last value of row prior to reading
+            matrix_row_t last_row_value = current_matrix[tmp];
+
+            // Check row pin state
+            if (row_value & row_mask[row]) {
+                // Pin HI, set col bit
+                current_matrix[tmp] |= (1 << col);
+            } else {
+                // Pin LOW, clear col bit
+                current_matrix[tmp] &= ~(1 << col);
+            }
+
+            // Determine if the matrix changed state
+            if ((last_row_value != current_matrix[tmp]) && !(changed)) {
+                changed = true;
+            }
+        }
+        // Unselect col
+        switch(col) {
+        case 0:
+            clear_pin(col_pins[col]);
+            break;
+        case 8:
+            tca6424_write_port(TCA6424_PORT1, 0);
+            break;
+        case 15:
+            tca6424_write_port(TCA6424_PORT0, p0_data&0x01);
+            break;
+        default:
+            break;
+        }
+    }
+
+    return changed;
+}