/* * BK Id: SCCS/s.ns16550.c 1.12 10/08/01 17:16:50 paulus *//* * COM1 NS16550 support */#include <linux/config.h>#include <linux/serialP.h>#include <linux/serial_reg.h>#include <asm/serial.h>/* Default serial baud rate */#define SERIAL_BAUD	9600extern void outb(int port, unsigned char val);extern unsigned char inb(int port);extern unsigned long ISA_io;static struct serial_state rs_table[RS_TABLE_SIZE] = {	SERIAL_PORT_DFNS	/* Defined in <asm/serial.h> */};static int shift;unsigned long serial_init(int chan) {	unsigned long com_port;	/* We need to find out which type io we're expecting.  If it's	 * 'SERIAL_IO_PORT', we get an offset from the isa_io_base.	 * If it's 'SERIAL_IO_MEM', we can the exact location.  -- Tom */	switch (rs_table[chan].io_type) {		case SERIAL_IO_PORT:			com_port = rs_table[chan].port;			break;		case SERIAL_IO_MEM:			com_port = (unsigned long)rs_table[chan].iomem_base;			break;		default:			/* We can't deal with it. */			return -1;	}	/* How far apart the registers are. */	shift = rs_table[chan].iomem_reg_shift;	/* See if port is present */	outb(com_port + (UART_LCR << shift), 0x00);	outb(com_port + (UART_IER << shift), 0x00);	/* Access baud rate */	outb(com_port + (UART_LCR << shift), 0x80);	/*	 * Test if serial port is unconfigured.	 * We assume that no-one uses less than 110 baud or	 * less than 7 bits per character these days.	 *  -- paulus.	 */	if (inb(com_port + (UART_DLM << shift)) > 4	    || (inb(com_port + (UART_LCR << shift)) & 2) == 0) {		/* Input clock. */		outb(com_port + (UART_DLL << shift),		     (BASE_BAUD / SERIAL_BAUD));		outb(com_port + (UART_DLM << shift),		     (BASE_BAUD / SERIAL_BAUD) >> 8);	}	 /* 8 data, 1 stop, no parity */	outb(com_port + (UART_LCR << shift), 0x03);	/* RTS/DTR */	outb(com_port + (UART_MCR << shift), 0x03);	/* Clear & enable FIFOs */	outb(com_port + (UART_FCR << shift), 0x07);	return (com_port);}voidserial_putc(unsigned long com_port, unsigned char c){	while ((inb(com_port + (UART_LSR << shift)) & UART_LSR_THRE) == 0)		;	outb(com_port, c);}unsigned charserial_getc(unsigned long com_port){	while ((inb(com_port + (UART_LSR << shift)) & UART_LSR_DR) == 0)		;	return inb(com_port);}intserial_tstc(unsigned long com_port){	return ((inb(com_port + (UART_LSR << shift)) & UART_LSR_DR) != 0);}