1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
100 lines
2.3 KiB
C
100 lines
2.3 KiB
C
/*
|
|
* COM1 NS16550 support
|
|
*/
|
|
|
|
#include <linux/config.h>
|
|
#include <linux/types.h>
|
|
#include <linux/serial.h>
|
|
#include <linux/serial_reg.h>
|
|
#include <asm/serial.h>
|
|
|
|
#include "nonstdio.h"
|
|
#include "serial.h"
|
|
|
|
#define SERIAL_BAUD 9600
|
|
|
|
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, void *ignored)
|
|
{
|
|
unsigned long com_port;
|
|
unsigned char lcr, dlm;
|
|
|
|
/* 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;
|
|
|
|
/* save the LCR */
|
|
lcr = inb(com_port + (UART_LCR << shift));
|
|
/* Access baud rate */
|
|
outb(com_port + (UART_LCR << shift), 0x80);
|
|
dlm = inb(com_port + (UART_DLM << shift));
|
|
/*
|
|
* 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 ((dlm <= 4) && (lcr & 2))
|
|
/* port is configured, put the old LCR back */
|
|
outb(com_port + (UART_LCR << shift), lcr);
|
|
else {
|
|
/* Input clock. */
|
|
outb(com_port + (UART_DLL << shift),
|
|
(BASE_BAUD / SERIAL_BAUD) & 0xFF);
|
|
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);
|
|
}
|