Add corne keyboard (#3119)

* Fork from helix

* Move rev2 to rev1

* Remove unused settings

* Move split_util to outof rev

* Setup KEYMAP for crkbd

* Remove old image

* Move keymaps directory and glcdfont.c

* Remove AUDIO in keymap

* Show keylog

* Show keylogs

* Show time log

* Remove EISU/KANA

* Use KEYMAP_kc

* Remove iota_gfx_record_user wrapping

* Remove unused settings for layer

* Add keylogger.c

* Fix uppercase letters to lower

* Add timelogger.c

* Default RGBLED_NUM = 27

* Remove unused setting

* Add mode icon reader

* Add matrix_write_ln

* Add layer_state_reader

* Move to lib directory

* Rename functions

* Add host_led_state_reader

* Add logo_reader

* Cleaning of iota_gfx_task

* Fix bugs and add key defines

* Remove unnecessary comments

* Update crkbd readme

* Move libs to lib directories

* Rename KEYMAP to LAYOUT

keyboards/crkbd/serial.h

@@ -0,0 +1,32 @@
+#ifndef MY_SERIAL_H
+#define MY_SERIAL_H
+
+#include "config.h"
+#include <stdbool.h>
+
+/* TODO:  some defines for interrupt setup */
+#define SERIAL_PIN_DDR DDRD
+#define SERIAL_PIN_PORT PORTD
+#define SERIAL_PIN_INPUT PIND
+
+#ifndef USE_SERIAL_PD2
+#define SERIAL_PIN_MASK _BV(PD0)
+#define SERIAL_PIN_INTERRUPT INT0_vect
+#else
+#define SERIAL_PIN_MASK _BV(PD2)
+#define SERIAL_PIN_INTERRUPT INT2_vect
+#endif
+
+#define SERIAL_SLAVE_BUFFER_LENGTH MATRIX_ROWS/2
+#define SERIAL_MASTER_BUFFER_LENGTH MATRIX_ROWS/2
+
+// Buffers for master - slave communication
+extern volatile uint8_t serial_slave_buffer[SERIAL_SLAVE_BUFFER_LENGTH];
+extern volatile uint8_t serial_master_buffer[SERIAL_MASTER_BUFFER_LENGTH];
+
+void serial_master_init(void);
+void serial_slave_init(void);
+int serial_update_buffers(void);
+bool serial_slave_data_corrupt(void);
+
+#endif