+/* Boards have uniqe mappings of {col, row} --> keycode.
+ * Column and row are 4 bits, but range only from 0..7;
+ * a PERSISTENT_KEY is "always on" and never reported.
+ */
+#define KEY_PERSISTENT 0x00800000
+#define KEY(col, row, keycode) (((col) << 28) | ((row) << 24) | (keycode))
+#define PERSISTENT_KEY(c, r) KEY(c, r, KEY_PERSISTENT)
+