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/* $Id: serial.h,v 1.2 2000/01/17 23:32:47 ralf Exp $
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1999 by Ralf Baechle
* Copyright (C) 1999, 2000 Silicon Graphics, Inc.
*/
#ifndef _ASM_SERIAL_H
#define _ASM_SERIAL_H
/*
* This assumes you have a 1.8432 MHz clock for your UART.
*
* It'd be nice if someone built a serial card with a 24.576 MHz
* clock, since the 16550A is capable of handling a top speed of 1.5
* megabits/second; but this requires the faster clock.
*/
#define BASE_BAUD (1843200 / 16)
/*
* Note about serial ports and consoles:
* For console output, everyone uses the IOC3 UARTA (offset 0x178)
* connected to the master node (look in ip27_setup_console() and
* ip27prom_console_write()).
*
* For serial (/dev/ttyS0 etc), we can not have hardcoded serial port
* addresses on a partitioned machine. Since we currently use the ioc3
* serial ports, we use dynamic serial port discovery that the serial.c
* driver uses for pci/pnp ports (there is an entry for the SGI ioc3
* boards in pci_boards[]). Unfortunately, UARTA's pio address is greater
* than UARTB's, although UARTA on o200s has traditionally been known as
* port 0. So, we just use one serial port from each ioc3 (since the
* serial driver adds addresses to get to higher ports).
*
* The first one to do a register_console becomes the preferred console
* (if there is no kernel command line console= directive). /dev/console
* (ie 5, 1) is then "aliased" into the device number returned by the
* "device" routine referred to in this console structure
* (ip27prom_console_dev).
*
* Also look in ip27-pci.c:pci_fixuop_ioc3() for some comments on working
* around ioc3 oddities in this respect.
*
* The IOC3 serials use a 22MHz clock rate with an additional divider by 3.
* (IOC3_BAUD = (22000000 / (3*16)))
*/
#define RS_TABLE_SIZE 64
#define SERIAL_PORT_DFNS
#endif /* _ASM_SERIAL_H */
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