Replace #define with enum for better compilation errors.

#include <linux/of.h>

/* Goldfish tty register's offsets */

#define	GOLDFISH_TTY_REG_BYTES_READY	0x04

#define	GOLDFISH_TTY_REG_CMD		0x08

#define	GOLDFISH_TTY_REG_DATA_PTR	0x10

#define	GOLDFISH_TTY_REG_DATA_LEN	0x14

#define	GOLDFISH_TTY_REG_DATA_PTR_HIGH	0x18

#define	GOLDFISH_TTY_REG_VERSION	0x20

enum {

	GOLDFISH_TTY_REG_BYTES_READY	= 0x04,

	GOLDFISH_TTY_REG_CMD		= 0x08,

	GOLDFISH_TTY_REG_DATA_PTR	= 0x10,

	GOLDFISH_TTY_REG_DATA_LEN	= 0x14,

	GOLDFISH_TTY_REG_DATA_PTR_HIGH	= 0x18,

	GOLDFISH_TTY_REG_VERSION	= 0x20,

};

/* Goldfish tty commands */

#define	GOLDFISH_TTY_CMD_INT_DISABLE	0

#define	GOLDFISH_TTY_CMD_INT_ENABLE	1

#define	GOLDFISH_TTY_CMD_WRITE_BUFFER	2

#define	GOLDFISH_TTY_CMD_READ_BUFFER	3

enum {

	GOLDFISH_TTY_CMD_INT_DISABLE	= 0,

	GOLDFISH_TTY_CMD_INT_ENABLE	= 1,

	GOLDFISH_TTY_CMD_WRITE_BUFFER	= 2,

	GOLDFISH_TTY_CMD_READ_BUFFER	= 3,

};

struct goldfish_tty {

	struct tty_port port;