#define _LINUX_TTY_FLIP_H
extern int tty_buffer_request_room(struct tty_struct *tty, size_t size);
-extern int tty_insert_flip_string(struct tty_struct *tty, unsigned char *chars, size_t size);
-extern int tty_insert_flip_string_flags(struct tty_struct *tty, unsigned char *chars, char *flags, size_t size);
+extern int tty_insert_flip_string(struct tty_struct *tty, const unsigned char *chars, size_t size);
+extern int tty_insert_flip_string_flags(struct tty_struct *tty, const unsigned char *chars, const char *flags, size_t size);
extern int tty_prepare_flip_string(struct tty_struct *tty, unsigned char **chars, size_t size);
extern int tty_prepare_flip_string_flags(struct tty_struct *tty, unsigned char **chars, char **flags, size_t size);