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

1 files changed, 49 insertions, 0 deletions

diff --git a/keyboards/crkbd/i2c.h b/keyboards/crkbd/i2c.h
new file mode 100644
index 0000000000..c15b6bc506
--- /dev/null
+++ b/keyboards/crkbd/i2c.h
@@ -0,0 +1,49 @@
+#ifndef I2C_H
+#define I2C_H
+
+#include <stdint.h>
+
+#ifndef F_CPU
+#define F_CPU 16000000UL
+#endif
+
+#define I2C_READ 1
+#define I2C_WRITE 0
+
+#define I2C_ACK 1
+#define I2C_NACK 0
+
+#define SLAVE_BUFFER_SIZE 0x10
+
+// i2c SCL clock frequency
+#define SCL_CLOCK  400000L
+
+extern volatile uint8_t i2c_slave_buffer[SLAVE_BUFFER_SIZE];
+
+void i2c_master_init(void);
+uint8_t i2c_master_start(uint8_t address);
+void i2c_master_stop(void);
+uint8_t i2c_master_write(uint8_t data);
+uint8_t i2c_master_read(int);
+void i2c_reset_state(void);
+void i2c_slave_init(uint8_t address);
+
+
+static inline unsigned char i2c_start_read(unsigned char addr) {
+  return i2c_master_start((addr << 1) | I2C_READ);
+}
+
+static inline unsigned char i2c_start_write(unsigned char addr) {
+  return i2c_master_start((addr << 1) | I2C_WRITE);
+}
+
+// from SSD1306 scrips
+extern unsigned char i2c_rep_start(unsigned char addr);
+extern void i2c_start_wait(unsigned char addr);
+extern unsigned char i2c_readAck(void);
+extern unsigned char i2c_readNak(void);
+extern unsigned char i2c_read(unsigned char ack);
+
+#define i2c_read(ack)  (ack) ? i2c_readAck() : i2c_readNak();
+
+#endif