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/*
* 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 9600
extern 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);
}
void
serial_putc(unsigned long com_port, unsigned char c)
{
while ((inb(com_port + (UART_LSR << shift)) & UART_LSR_THRE) == 0)
;
outb(com_port, c);
}
unsigned char
serial_getc(unsigned long com_port)
{
while ((inb(com_port + (UART_LSR << shift)) & UART_LSR_DR) == 0)
;
return inb(com_port);
}
int
serial_tstc(unsigned long com_port)
{
return ((inb(com_port + (UART_LSR << shift)) & UART_LSR_DR) != 0);
}
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