1 files changed, 60 insertions, 0 deletions
diff --git a/quantum/split_common/i2c.h b/quantum/split_common/i2c.h
new file mode 100644
index 000000000..b4c72bde0
--- /dev/null
+++ b/quantum/split_common/i2c.h
@@ -0,0 +1,60 @@
+#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
+
+// Address location defines (Keymap should be last, as it's size is dynamic)
+#define I2C_BACKLIT_START   0x00
+// Need 4 bytes for RGB (32 bit)
+#define I2C_RGB_START       0x01
+#define I2C_KEYMAP_START    0x06
+
+// Slave buffer (8bit per)
+// Rows per hand + backlit space + rgb space
+// TODO : Make this dynamically sized
+#define SLAVE_BUFFER_SIZE 0x20
+
+// i2c SCL clock frequency
+#define SCL_CLOCK  400000L
+
+// Support 8bits right now (8 cols) will need to edit to take higher (code exists in delta split?)
+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_write_data(void *const TXdata, uint8_t dataLen);
+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