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ns16550.c revision 1.4 
      1 /*	$NetBSD: ns16550.c,v 1.4 1999/06/24 01:10:32 sakamoto 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 "ns16550.h"
     39 
     40 volatile struct NS16550 *
     41 NS16550_init(addr, speed)
     42 	int addr;
     43 	int speed;
     44 {
     45 	volatile struct NS16550 *com_port;
     46 
     47 	com_port = (struct NS16550 *)(COMBASE + addr);
     48 
     49 	com_port->lcr = 0x80;  /* Access baud rate */
     50 	speed = comspeed(speed);
     51 	com_port->dll = speed;
     52 	com_port->dlm = speed >> 8;
     53 
     54 	com_port->lcr = 0x03;  /* 8 data, 1 stop, no parity */
     55 	com_port->mcr = 0x00;
     56 	com_port->fcr = 0x07;  /* Clear & enable FIFOs */
     57 	com_port->ier = 0x00;
     58 	return (com_port);
     59 }
     60 
     61 
     62 NS16550_putc(volatile struct NS16550 *com_port, unsigned char c)
     63 {
     64 	volatile int i;
     65 	while ((com_port->lsr & LSR_THRE) == 0) ;
     66 	com_port->thr = c;
     67 }
     68 
     69 unsigned char NS16550_getc(volatile struct NS16550 *com_port)
     70 {
     71 	while ((com_port->lsr & LSR_DR) == 0) ;
     72 	return (com_port->rbr);
     73 }
     74 
     75 int NS16550_scankbd(volatile struct NS16550 *com_port)
     76 {
     77 	if ((com_port->lsr & LSR_DR) == 0)
     78 		return -1;
     79 	return (com_port->rbr);
     80 }
     81 
     82 NS16550_test(volatile struct NS16550 *com_port)
     83 {
     84 	return ((com_port->lsr & LSR_DR) != 0);
     85 }
     86 #endif /* CONS_SERIAL */
     87