struct tty_struct *tty, int irq);
extern int parse_chan_pair(char *str, struct line *line, int device,
const struct chan_opts *opts, char **error_out);
struct tty_struct *tty, int irq);
extern int parse_chan_pair(char *str, struct line *line, int device,
const struct chan_opts *opts, char **error_out);