124 struct uart_8250_port {  struct
125 	struct uart_port	port;
126 	struct timer_list	timer;		/* "no irq" timer */
127 	struct list_head	list;		/* ports on this IRQ */
128 	u32			capabilities;	/* port capabilities */
129 	u16			bugs;		/* port bugs */
130 	unsigned int		tx_loadsz;	/* transmit fifo load size */
131 	unsigned char		acr;
132 	unsigned char		fcr;
133 	unsigned char		ier;
134 	unsigned char		lcr;
135 	unsigned char		mcr;
136 	unsigned char		cur_iotype;	/* Running I/O type */
160 	u32			(*dl_read)(struct uart_8250_port *up);  argument
161 	void			(*dl_write)(struct uart_8250_port *up, u32 value);  argument
164 	void			(*rs485_start_tx)(struct uart_8250_port *);  argument
165 	void			(*rs485_stop_tx)(struct uart_8250_port *);  argument
172 static inline struct uart_8250_port *up_to_u8250p(struct uart_port *up)  in up_to_u8250p()  argument