2 files changed, 24 insertions, 3 deletions

diff --git a/common/keyboard.c b/common/keyboard.c
index 432ea8934..91f321d9c 100644
--- a/common/keyboard.c
+++ b/common/keyboard.c
@@ -34,6 +34,24 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #endif
 
 
+#ifdef MATRIX_HAS_GHOST
+static bool has_ghost_in_row(uint8_t row)
+{
+    matrix_row_t matrix_row = matrix_get_row(row);
+    // No ghost exists when less than 2 keys are down on the row
+    if (((matrix_row - 1) & matrix_row) == 0)
+        return false;
+
+    // Ghost occurs when the row shares column line with other row
+    for (uint8_t i=0; i < MATRIX_ROWS; i++) {
+        if (i != row && (matrix_get_row(i) & matrix_row))
+            return true;
+    }
+    return false;
+}
+#endif
+
+
 void keyboard_init(void)
 {
     // TODO: configuration of sendchar impl
@@ -81,7 +99,12 @@ void keyboard_task(void)
         matrix_change = matrix_row ^ matrix_prev[r];
         if (matrix_change) {
             if (debug_matrix) matrix_print();
-
+#ifdef MATRIX_HAS_GHOST
+            if (has_ghost_in_row(r)) {
+                matrix_prev[r] = matrix_row;
+                continue;
+            }
+#endif
             for (uint8_t c = 0; c < MATRIX_COLS; c++) {
                 if (matrix_change & ((matrix_row_t)1<<c)) {
                     action_exec((keyevent_t){
diff --git a/common/matrix.h b/common/matrix.h
index b3332d5ff..48203c71d 100644
--- a/common/matrix.h
+++ b/common/matrix.h
@@ -45,8 +45,6 @@ void matrix_init(void);
 uint8_t matrix_scan(void);
 /* whether modified from previous scan. used after matrix_scan. */
 bool matrix_is_modified(void);
-/* whether ghosting occur on matrix. */
-bool matrix_has_ghost(void);
 /* whether a swtich is on */
 bool matrix_is_on(uint8_t row, uint8_t col);
 /* matrix state on row */