dca.c

早期freebsd实现

/*
 * Copyright (c) 1988 University of Utah.
 * Copyright (c) 1990, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * the Systems Programming Group of the University of Utah Computer
 * Science Department.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	@(#)dca.c	8.1 (Berkeley) 6/10/93
 */

#ifdef DCACONSOLE
#include <sys/param.h>
#include <hp/dev/dcareg.h>
#include <machine/cpu.h>
#include <hp/dev/cons.h>

struct dcadevice *dcacnaddr = 0;

dcaprobe(cp)
	struct consdev *cp;
{
	register struct dcadevice *dca;

	dcacnaddr = (struct dcadevice *) sctoaddr(CONSCODE);
	if (badaddr((char *)dcacnaddr)) {
		cp->cn_pri = CN_DEAD;
		return;
	}
#ifdef FORCEDCACONSOLE
	cp->cn_pri = CN_REMOTE;
#else
	dca = dcacnaddr;
	switch (dca->dca_id) {
	case DCAID0:
	case DCAID1:
		cp->cn_pri = CN_NORMAL;
		break;
	case DCAREMID0:
	case DCAREMID1:
		cp->cn_pri = CN_REMOTE;
		break;
	default:
		cp->cn_pri = CN_DEAD;
		break;
	}
#endif
}

dcainit(cp)
	struct consdev *cp;
{
	register struct dcadevice *dca = dcacnaddr;

	dca->dca_reset = 0xFF;
	DELAY(100);
	dca->dca_ic = 0;
	dca->dca_cfcr = CFCR_DLAB;
	dca->dca_data = DCABRD(9600) & 0xFF;
	dca->dca_ier = DCABRD(9600) >> 8;
	dca->dca_cfcr = CFCR_8BITS;
}

#ifndef SMALL
dcagetchar()
{
	register struct dcadevice *dca = dcacnaddr;
	short stat;
	int c;

	if (((stat = dca->dca_lsr) & LSR_RXRDY) == 0)
		return(0);
	c = dca->dca_data;
	return(c);
}
#else
dcagetchar()
{
	return(0);
}
#endif

dcaputchar(c)
	register int c;
{
	register struct dcadevice *dca = dcacnaddr;
	register int timo;
	short stat;

	/* wait a reasonable time for the transmitter to come ready */
	timo = 50000;
	while (((stat = dca->dca_lsr) & LSR_TXRDY) == 0 && --timo)
		;
	dca->dca_data = c;
	/* wait for this transmission to complete */
	timo = 1000000;
	while (((stat = dca->dca_lsr) & LSR_TXRDY) == 0 && --timo)
		;
}
#endif