void (*unthrottle)(struct uart_port *);
void (*send_xchar)(struct uart_port *, char ch);
void (*stop_rx)(struct uart_port *);
+ void (*start_rx)(struct uart_port *);
void (*enable_ms)(struct uart_port *);
void (*break_ctl)(struct uart_port *, int ctl);
int (*startup)(struct uart_port *);