add support for encoders to core

quantum/encoder.h

@@ -0,0 +1,29 @@
+/*
+ * Copyright 2018 Jack Humbert <jack.humb@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/>.
+ */
+
+#pragma once
+
+#include "quantum.h"
+
+#define COUNTRECLOCKWISE 0
+#define CLOCKWISE 1
+
+void encoder_init(void);
+void encoder_read(void);
+
+void encoder_update_kb(int8_t index, bool clockwise);
+void encoder_update_user(int8_t index, bool clockwise);