TTY line discipline example structure

tty_ldisc.h

struct tty_ldisc {
  int magic;
  char *name;
  int num;
  int flags; /*          * The following routines are called from above. */
  int (*open)(struct tty_struct *);
  void (*close)(struct tty_struct *);
  void (*flush_buffer)(struct tty_struct *tty);
  ssize_t (*chars_in_buffer)(struct tty_struct *tty);
  ssize_t (*read)(struct tty_struct *tty, struct file *file, unsigned char *buf,
                  size_t nr);
  ssize_t (*write)(struct tty_struct *tty, struct file *file,
                   const unsigned char *buf, size_t nr);
  int (*ioctl)(struct tty_struct *tty, struct file *file, unsigned int cmd,
               unsigned long arg);
  void (*set_termios)(struct tty_struct *tty, struct termios *old);
  unsigned int (*poll)(
      struct tty_struct *, struct file *,
      struct poll_table_struct
          *); /*          * The following routines are called from below. */
  void (*receive_buf)(struct tty_struct *, const unsigned char *cp, char *fp,
                      int count);
  int (*receive_room)(struct tty_struct *);
  void (*write_wakeup)(struct tty_struct *);
};