com.c

早期freebsd实现

/*-
 * Copyright (c) 1991, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * 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.
 *
 *	@(#)com.c	8.1 (Berkeley) 6/11/93
 */

#include "com.h"
#if NCOM > 0
/*
 * COM driver, based on HP dca driver
 * uses National Semiconductor NS16450/NS16550AF UART
 */
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/ioctl.h>
#include <sys/tty.h>
#include <sys/proc.h>
#include <sys/user.h>
#include <sys/conf.h>
#include <sys/file.h>
#include <sys/uio.h>
#include <sys/kernel.h>
#include <sys/syslog.h>

#include <i386/isa/isa_device.h>
#include <i386/isa/comreg.h>
#include <i386/isa/ic/ns16550.h>

void	comstart();
int 	comprobe(), comattach(), comintr(), comparam();

struct	isa_driver comdriver = {
	comprobe, comattach, "com"
};

int	comsoftCAR;
int	com_active;
int	com_hasfifo;
int	ncom = NCOM;
#ifdef COMCONSOLE
int	comconsole = COMCONSOLE;
#else
int	comconsole = -1;
#endif
int	comconsinit;
int	comdefaultrate = TTYDEF_SPEED;
int	commajor;
short com_addr[NCOM];
struct	tty com_tty[NCOM];

struct speedtab comspeedtab[] = {
	0,	0,
	50,	COMBRD(50),
	75,	COMBRD(75),
	110,	COMBRD(110),
	134,	COMBRD(134),
	150,	COMBRD(150),
	200,	COMBRD(200),
	300,	COMBRD(300),
	600,	COMBRD(600),
	1200,	COMBRD(1200),
	1800,	COMBRD(1800),
	2400,	COMBRD(2400),
	4800,	COMBRD(4800),
	9600,	COMBRD(9600),
	19200,	COMBRD(19200),
	38400,	COMBRD(38400),
	57600,	COMBRD(57600),
	-1,	-1
};

extern	struct tty *constty;
#ifdef KGDB
#include <machine/remote-sl.h>

extern int kgdb_dev;
extern int kgdb_rate;
extern int kgdb_debug_init;
#endif

#define	UNIT(x)		minor(x)

comprobe(dev)
struct isa_device *dev;
{
	/* force access to id reg */
	outb(dev->id_iobase+com_cfcr, inb (dev->id_iobase+com_cfcr) & ~0x80);
	outb(dev->id_iobase+com_iir, 0);
	if ((inb(dev->id_iobase+com_iir) & 0x38) == 0)
		return(1);
	return(1);

}


int
comattach(isdp)
struct isa_device *isdp;
{
	struct	tty	*tp;
	u_char		unit;
	int		port = isdp->id_iobase;

	unit = isdp->id_unit;
	if (unit == comconsole)
		DELAY(100000);
	com_addr[unit] = port;
	com_active |= 1 << unit;
	comsoftCAR |= 1 << unit;	/* XXX */

	/* look for a NS 16550AF UART with FIFOs */
	outb(port+com_fifo, FIFO_ENABLE|FIFO_RCV_RST|FIFO_XMT_RST|FIFO_TRIGGER_14);
	DELAY(100);
	if ((inb(port+com_iir) & IIR_FIFO_MASK) == IIR_FIFO_MASK)
		com_hasfifo |= 1 << unit;

	outb(port+com_ier, 0);
	outb(port+com_mcr, 0 | MCR_IENABLE);
#ifdef KGDB
	if (kgdb_dev == makedev(commajor, unit)) {
		if (comconsole == unit)
			kgdb_dev = -1;	/* can't debug over console port */
		else {
			(void) cominit(unit, kgdb_rate);
			if (kgdb_debug_init) {
				/*
				 * Print prefix of device name,
				 * let kgdb_connect print the rest.
				 */
				printf("com%d: ", unit);
				kgdb_connect(1);
			} else
				printf("com%d: kgdb enabled\n", unit);
		}
	}
#endif
	/*
	 * Need to reset baud rate, etc. of next print so reset comconsinit.
	 * Also make sure console is always "hardwired"
	 */
	if (unit == comconsole) {
		comconsinit = 0;
		comsoftCAR |= (1 << unit);
	}
	return (1);
}

/* ARGSUSED */
#ifdef __STDC__
comopen(dev_t dev, int flag, int mode, struct proc *p)
#else
comopen(dev, flag, mode, p)
	dev_t dev;
	int flag, mode;
	struct proc *p;
#endif
{
	register struct tty *tp;
	register int unit;
	int error = 0;
 
	unit = UNIT(dev);
	if (unit >= NCOM || (com_active & (1 << unit)) == 0)
		return (ENXIO);
	tp = &com_tty[unit];
	tp->t_oproc = comstart;
	tp->t_param = comparam;
	tp->t_dev = dev;
	if ((tp->t_state & TS_ISOPEN) == 0) {
		tp->t_state |= TS_WOPEN;
		ttychars(tp);
		if (tp->t_ispeed == 0) {
			tp->t_iflag = TTYDEF_IFLAG;
			tp->t_oflag = TTYDEF_OFLAG;
			tp->t_cflag = TTYDEF_CFLAG;
			tp->t_lflag = TTYDEF_LFLAG;
			tp->t_ispeed = tp->t_ospeed = comdefaultrate;
		}
		comparam(tp, &tp->t_termios);
		ttsetwater(tp);
	} else if (tp->t_state&TS_XCLUDE && p->p_ucred->cr_uid != 0)
		return (EBUSY);
	(void) spltty();
	(void) commctl(dev, MCR_DTR | MCR_RTS, DMSET);
	if ((comsoftCAR & (1 << unit)) || (commctl(dev, 0, DMGET) & MSR_DCD))
		tp->t_state |= TS_CARR_ON;
	while ((flag&O_NONBLOCK) == 0 && (tp->t_cflag&CLOCAL) == 0 &&
	       (tp->t_state & TS_CARR_ON) == 0) {
		tp->t_state |= TS_WOPEN;
		if (error = ttysleep(tp, (caddr_t)&tp->t_rawq, TTIPRI | PCATCH,
		    ttopen, 0))
			break;
	}
	(void) spl0();
	if (error == 0)
		error = (*linesw[tp->t_line].l_open)(dev, tp);
	return (error);
}
 
/*ARGSUSED*/
comclose(dev, flag, mode, p)
	dev_t dev;
	int flag, mode;
	struct proc *p;
{
	register struct tty *tp;
	register com;
	register int unit;
 
	unit = UNIT(dev);
	com = com_addr[unit];
	tp = &com_tty[unit];
	(*linesw[tp->t_line].l_close)(tp, flag);
	outb(com+com_cfcr, inb(com+com_cfcr) & ~CFCR_SBREAK);
#ifdef KGDB
	/* do not disable interrupts if debugging */
	if (kgdb_dev != makedev(commajor, unit))
#endif
	outb(com+com_ier, 0);
	if (tp->t_cflag&HUPCL || tp->t_state&TS_WOPEN || 
	    (tp->t_state&TS_ISOPEN) == 0)
		(void) commctl(dev, 0, DMSET);
	ttyclose(tp);
	return(0);
}
 
comread(dev, uio, flag)
	dev_t dev;
	struct uio *uio;
{
	register struct tty *tp = &com_tty[UNIT(dev)];
 
	return ((*linesw[tp->t_line].l_read)(tp, uio, flag));
}
 
comwrite(dev, uio, flag)
	dev_t dev;
	struct uio *uio;
{
	int unit = UNIT(dev);
	register struct tty *tp = &com_tty[unit];
 
	/*
	 * (XXX) We disallow virtual consoles if the physical console is
	 * a serial port.  This is in case there is a display attached that
	 * is not the console.  In that situation we don't need/want the X
	 * server taking over the console.
	 */
	if (constty && unit == comconsole)
		constty = NULL;
	return ((*linesw[tp->t_line].l_write)(tp, uio, flag));
}
 
comintr(unit)
	register int unit;
{
	register com;
	register u_char code;
	register struct tty *tp;

	com = com_addr[unit];
	while (1) {
		code = inb(com+com_iir);
		switch (code & IIR_IMASK) {
		case IIR_NOPEND:
			return (1);
		case IIR_RXTOUT:
		case IIR_RXRDY:
			tp = &com_tty[unit];
/*
 * Process received bytes.  Inline for speed...
 */
#ifdef KGDB
#define	RCVBYTE() \
			code = inb(com+com_data); \
			if ((tp->t_state & TS_ISOPEN) == 0) { \
				if (kgdb_dev == makedev(commajor, unit) && \
				    code == FRAME_END) \
					kgdb_connect(0); /* trap into kgdb */ \
			} else \
				(*linesw[tp->t_line].l_rint)(code, tp)
#else
#define	RCVBYTE() \
			code = inb(com+com_data); \
			if (tp->t_state & TS_ISOPEN) \
				(*linesw[tp->t_line].l_rint)(code, tp)
#endif

			RCVBYTE();

			if (com_hasfifo & (1 << unit))
				while ((code = inb(com+com_lsr)) & LSR_RCV_MASK) {
					if (code == LSR_RXRDY) {
						RCVBYTE();
					} else
						comeint(unit, code, com);
				}
			break;
		case IIR_TXRDY:
			tp = &com_tty[unit];
			tp->t_state &=~ (TS_BUSY|TS_FLUSH);
			if (tp->t_line)
				(*linesw[tp->t_line].l_start)(tp);
			else
				comstart(tp);
			break;
		case IIR_RLS:
			comeint(unit, inb(com+com_lsr), com);
			break;
		default:
			if (code & IIR_NOPEND)
				return (1);
			log(LOG_WARNING, "com%d: weird interrupt: 0x%x\n",
			    unit, code);
			/* fall through */
		case IIR_MLSC:
			commint(unit, com);
			break;
		}
	}
}

comeint(unit, stat, com)
	register int unit, stat;
	register com;
{
	register struct tty *tp;
	register int c;

	tp = &com_tty[unit];