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ns16550.c revision 1.6 
      1 /*	$NetBSD: ns16550.c,v 1.6 2005/06/28 21:03:02 junyoung Exp $	*/
      2 
      3 /*-
      4  * Copyright (C) 1995-1997 Gary Thomas (gdt (at) linuxppc.org)
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *      This product includes software developed by Gary Thomas.
     18  * 4. The name of the author may not be used to endorse or promote products
     19  *    derived from this software without specific prior written permission.
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     22  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     23  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     24  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     26  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     27  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     28  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     29  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     30  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     31  */
     32 
     33 #ifdef CONS_SERIAL
     34 /*
     35  * NS16550 support
     36  */
     37 
     38 #include <lib/libsa/stand.h>
     39 #include "boot.h"
     40 #include "ns16550.h"
     41 
     42 volatile struct NS16550 *
     43 NS16550_init(addr, speed)
     44 	int addr;
     45 	int speed;
     46 {
     47 	struct NS16550 *com_port;
     48 
     49 	com_port = (struct NS16550 *)(COMBASE + addr);
     50 
     51 	com_port->lcr = 0x80;  /* Access baud rate */
     52 	speed = comspeed(speed);
     53 	com_port->dll = speed;
     54 	com_port->dlm = speed >> 8;
     55 
     56 	com_port->lcr = 0x03;  /* 8 data, 1 stop, no parity */
     57 	com_port->mcr = 0x00;
     58 	com_port->fcr = 0x07;  /* Clear & enable FIFOs */
     59 	com_port->ier = 0x00;
     60 
     61 	return (com_port);
     62 }
     63 
     64 void
     65 NS16550_putc(com_port, c)
     66 	volatile struct NS16550 *com_port;
     67 	int c;
     68 {
     69 	while ((com_port->lsr & LSR_THRE) == 0)
     70 		;
     71 	com_port->thr = c;
     72 }
     73 
     74 int
     75 NS16550_getc(com_port)
     76 	volatile struct NS16550 *com_port;
     77 {
     78 	while ((com_port->lsr & LSR_DR) == 0)
     79 		;
     80 	return (com_port->rbr);
     81 }
     82 
     83 int
     84 NS16550_scankbd(com_port)
     85 	volatile struct NS16550 *com_port;
     86 {
     87 	if ((com_port->lsr & LSR_DR) == 0)
     88 		return -1;
     89 	return (com_port->rbr);
     90 }
     91 
     92 int
     93 NS16550_test(com_port)
     94 	volatile struct NS16550 *com_port;
     95 {
     96 	return ((com_port->lsr & LSR_DR) != 0);
     97 }
     98 #endif /* CONS_SERIAL */
     99