com.c

国产CPU－龙芯（loongson)BIOS源代码

/*	$OpenBSD: com.c,v 1.50 1999/08/08 16:28:17 niklas Exp $	*/
/*	$NetBSD: com.c,v 1.82.4.1 1996/06/02 09:08:00 mrg Exp $	*/

/*-
 * Copyright (c) 1993, 1994, 1995, 1996
 *	Charles M. Hannum.  All rights reserved.
 * Copyright (c) 1991 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	7.5 (Berkeley) 5/16/91
 */

/*
 * 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 <sys/types.h>
#include <sys/device.h>
/*
#include <sys/vnode.h>
*/

#include <machine/bus.h>
#include <machine/intr.h>

#include <dev/ic/comreg.h>
#include <dev/ic/comvar.h>
#include <dev/ic/ns16550reg.h>
#define	com_lcr	com_cfcr

#ifndef NULL
#define NULL	0
#endif

/* XXX: These belong elsewhere */
cdev_decl(com);
bdev_decl(com);

static u_char tiocm_xxx2mcr __P((int));

/*
 * XXX the following two cfattach structs should be different, and possibly
 * XXX elsewhere.
 */
int	comprobe __P((struct device *, void *, void *));
void	comattach __P((struct device *, struct device *, void *));
void	compwroff __P((struct com_softc *));
void	com_raisedtr __P((void *));

#if NCOM_ISA
struct cfattach com_isa_ca = {
	sizeof(struct com_softc), comprobe, comattach
};
#endif

#if NCOM_ISAPNP
struct cfattach com_isapnp_ca = {
	sizeof(struct com_softc), comprobe, comattach
};
#endif

struct cfdriver com_cd = {
	NULL, "com", DV_TTY
};

#ifndef CONSPEED
#define	CONSPEED B9600
#endif

#ifdef COMCONSOLE
int	comdefaultrate = CONSPEED;		/* XXX why set default? */
#else
int	comdefaultrate = TTYDEF_SPEED;
#endif
int	comconsaddr;
int	comconsinit;
int	comconsattached;
bus_space_tag_t comconsiot;
bus_space_handle_t comconsioh;
tcflag_t comconscflag = TTYDEF_CFLAG;

int	commajor;
int	comsopen = 0;
int	comevents = 0;

#ifdef KGDB
#include <machine/remote-sl.h>
extern int kgdb_dev;
extern int kgdb_rate;
extern int kgdb_debug_init;
#endif

#define	DEVUNIT(x)	(minor(x) & 0x7f)
#define	DEVCUA(x)	(minor(x) & 0x80)

/* Macros to clear/set/test flags. */
#define	SET(t, f)	(t) |= (f)
#define	CLR(t, f)	(t) &= ~(f)
#define	ISSET(t, f)	((t) & (f))

/* Macros for determining bus type. */
#if NCOM_ISA
#define IS_ISA(parent) \
    (strcmp((parent)->dv_cfdata->cf_driver->cd_name, "isa") == 0)
#else
#define IS_ISA(parent) 0
#endif

#if NCOM_ISAPNP
#define IS_ISAPNP(parent) \
    (strcmp((parent)->dv_cfdata->cf_driver->cd_name, "isapnp") == 0)
#else
#define IS_ISAPNP(parent) 0
#endif

int
comspeed(speed)
	long speed;
{
#define	divrnd(n, q)	(((n)*2/(q)+1)/2)	/* divide and round off */

	int x, err;

	if (speed == 0)
		return 0;
	if (speed < 0)
		return -1;
	x = divrnd((COM_FREQ / 16), speed);
	if (x <= 0)
		return -1;
	err = divrnd((COM_FREQ / 16) * 1000, speed * x) - 1000;
	if (err < 0)
		err = -err;
	if (err > COM_TOLERANCE)
		return -1;
	return x;

#undef	divrnd(n, q)
}

int
comprobe1(iot, ioh)
	bus_space_tag_t iot;
	bus_space_handle_t ioh;
{
	int i, k;

	/* force access to id reg */
	bus_space_write_1(iot, ioh, com_lcr, 0);
	bus_space_write_1(iot, ioh, com_iir, 0);
	for (i = 0; i < 32; i++) {
	    k = bus_space_read_1(iot, ioh, com_iir);
	    if (k & 0x38) {
		bus_space_read_1(iot, ioh, com_data); /* cleanup */
	    } else
		break;
	}
	if (i >= 32) 
	    return 0;

	return 1;
}

int
comprobe(parent, match, aux)
	struct device *parent;
	void *match, *aux;
{
	bus_space_tag_t iot;
	bus_space_handle_t ioh;
	int iobase, needioh;
	int rv = 1;

	/*
	 * XXX should be broken out into functions for isa probe and
	 * XXX for commulti probe, with a helper function that contains
	 * XXX most of the interesting stuff.
	 */
#if NCOM_ISA || NCOM_ISAPNP
	if (IS_ISA(parent) || IS_ISAPNP(parent)) {
		struct isa_attach_args *ia = aux;

		iot = ia->ia_iot;
		iobase = ia->ia_iobase;
		if (IS_ISAPNP(parent)) {
			ioh = ia->ia_ioh;
			needioh = 0;
		} else
			needioh = 1;
	} else
#endif
		return(0);			/* This cannot happen */

	/* if it's in use as console, it's there. */
	if (iobase == comconsaddr && !comconsattached)
		goto out;

	if (needioh && bus_space_map(iot, iobase, COM_NPORTS, 0, &ioh)) {
		rv = 0;
		goto out;
	}
	rv = comprobe1(iot, ioh);
	if (needioh)
		bus_space_unmap(iot, ioh, COM_NPORTS);

out:
#if NCOM_ISA
	if (rv && IS_ISA(parent)) {
		struct isa_attach_args *ia = aux;

		ia->ia_iosize = COM_NPORTS;
		ia->ia_msize = 0;
	}
#endif
	return (rv);
}

void
comattach(parent, self, aux)
	struct device *parent, *self;
	void *aux;
{
	struct com_softc *sc = (void *)self;
	int iobase, irq;
	bus_space_tag_t iot;
	bus_space_handle_t ioh;
	u_int8_t lcr;

	/*
	 * XXX should be broken out into functions for isa attach and
	 * XXX for commulti attach, with a helper function that contains
	 * XXX most of the interesting stuff.
	 */
	sc->sc_hwflags = 0;
	sc->sc_swflags = 0;
#if NCOM_ISA || NCOM_ISAPNP
	if (IS_ISA(parent) || IS_ISAPNP(parent)) {
		struct isa_attach_args *ia = aux;

		/*
		 * We're living on an isa.
		 */
		iobase = ia->ia_iobase;
		iot = ia->ia_iot;
		if (IS_ISAPNP(parent)) {
			/* No console support! */
			ioh = ia->ia_ioh;
		} else {
	       		if (iobase != comconsaddr) {
				if (bus_space_map(iot, iobase, COM_NPORTS, 0,
				    &ioh))
					panic("comattach: io mapping failed");
			} else
				ioh = comconsioh;
		}
		irq = ia->ia_irq;
	} else
#endif
		panic("comattach: impossible");

	sc->sc_iot = iot;
	sc->sc_ioh = ioh;
	sc->sc_iobase = iobase;

	if (iobase == comconsaddr) {
		comconsattached = 1;

		/* 
		 * Need to reset baud rate, etc. of next print so reset
		 * comconsinit.  Also make sure console is always "hardwired".
		 */
		delay(1000);			/* wait for output to finish */
		comconsinit = 0;
		SET(sc->sc_hwflags, COM_HW_CONSOLE);
		SET(sc->sc_swflags, COM_SW_SOFTCAR);
	}

	/*
	 * Probe for all known forms of UART.
	 */
	lcr = bus_space_read_1(iot, ioh, com_lcr);

	bus_space_write_1(iot, ioh, com_lcr, 0xbf);
	bus_space_write_1(iot, ioh, com_efr, 0);
	bus_space_write_1(iot, ioh, com_lcr, 0);

	bus_space_write_1(iot, ioh, com_fifo, FIFO_ENABLE);
	delay(100);

	switch(bus_space_read_1(iot, ioh, com_iir) >> 6) {
	case 0:
		sc->sc_uarttype = COM_UART_16450;
		break;
	case 2:
		sc->sc_uarttype = COM_UART_16550;
		break;
	case 3:
		sc->sc_uarttype = COM_UART_16550A;
		break;
	default:
		sc->sc_uarttype = COM_UART_UNKNOWN;
		break;
	}

	if (sc->sc_uarttype == COM_UART_16550A) { /* Probe for ST16650s */
		bus_space_write_1(iot, ioh, com_lcr, lcr | LCR_DLAB);
		if (bus_space_read_1(iot, ioh, com_efr) == 0) {
			sc->sc_uarttype = COM_UART_ST16650;
		} else {
			bus_space_write_1(iot, ioh, com_lcr, 0xbf);
			if (bus_space_read_1(iot, ioh, com_efr) == 0)
				sc->sc_uarttype = COM_UART_ST16650V2;
		}
	}

	bus_space_write_1(iot, ioh, com_lcr, lcr);
	if (sc->sc_uarttype == COM_UART_16450) { /* Probe for 8250 */
		u_int8_t scr0, scr1, scr2;

		scr0 = bus_space_read_1(iot, ioh, com_scratch);
		bus_space_write_1(iot, ioh, com_scratch, 0xa5);
		scr1 = bus_space_read_1(iot, ioh, com_scratch);
		bus_space_write_1(iot, ioh, com_scratch, 0x5a);
		scr2 = bus_space_read_1(iot, ioh, com_scratch);
		bus_space_write_1(iot, ioh, com_scratch, scr0);

		if ((scr1 != 0xa5) || (scr2 != 0x5a))
			sc->sc_uarttype = COM_UART_8250;
	}

	/*
	 * Print UART type and initialize ourself.
	 */
	sc->sc_fifolen = 1;	/* default */
	switch (sc->sc_uarttype) {
	case COM_UART_UNKNOWN:
		printf(": unknown uart\n");
		break;
	case COM_UART_8250:
		printf(": ns8250, no fifo\n");
		break;
	case COM_UART_16450:
		printf(": ns16450, no fifo\n");
		break;
	case COM_UART_16550:
		printf(": ns16550, no working fifo\n");
		break;
	case COM_UART_16550A:
		printf(": ns16550a, 16 byte fifo\n");
		SET(sc->sc_hwflags, COM_HW_FIFO);
		sc->sc_fifolen = 16;
		break;
	case COM_UART_ST16650:
		printf(": st16650, no working fifo\n");
		break;
	case COM_UART_ST16650V2:
		printf(": st16650, 32 byte fifo\n");
		SET(sc->sc_hwflags, COM_HW_FIFO);
		sc->sc_fifolen = 32;
		break;
	case COM_UART_TI16750:
		printf(": ti16750, 64 byte fifo\n");
		SET(sc->sc_hwflags, COM_HW_FIFO);
		sc->sc_fifolen = 64;
		break;
	default:
		panic("comattach: bad fifo type");
	}

	/* clear and disable fifo */
	bus_space_write_1(iot, ioh, com_fifo, FIFO_RCV_RST | FIFO_XMT_RST);
	(void)bus_space_read_1(iot, ioh, com_data);
	bus_space_write_1(iot, ioh, com_fifo, 0);

	/* disable interrupts */
	bus_space_write_1(iot, ioh, com_ier, 0);
	bus_space_write_1(iot, ioh, com_mcr, 0);

	/* XXX maybe move up some? */
	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE))
		printf("%s: console\n", sc->sc_dev.dv_xname);

	/*
	 * If there are no enable/disable functions, assume the device
	 * is always enabled.
	 */
	if (!sc->enable)
		sc->enabled = 1;
}

int
com_detach(self, flags)
	struct device *self;
	int flags;
{
	struct com_softc *sc = (struct com_softc *)self;
	int maj, mn;

	/* locate the major number */
	for (maj = 0; maj < nchrdev; maj++)
		if (cdevsw[maj].d_open == comopen)
			break;

	/* Nuke the vnodes for any open instances. */
	mn = self->dv_unit;
	vdevgone(maj, mn, mn, VCHR);

	/* XXX a symbolic constant for the cua bit would be nicer. */
	mn |= 0x80;
	vdevgone(maj, mn, mn, VCHR);

	/* Detach and free the tty. */
	if (sc->sc_tty) {
		tty_detach(sc->sc_tty);
		ttyfree(sc->sc_tty);
	}

	untimeout(compoll, NULL);
	untimeout(com_raisedtr, sc);
	untimeout(comdiag, sc);

	return (0);
}

int
com_activate(self, act)
	struct device *self;
	enum devact act;
{
	struct com_softc *sc = (struct com_softc *)self;
	int s, rv = 0;

	s = spltty();
	switch (act) {
	case DVACT_ACTIVATE:
		rv = EOPNOTSUPP;
		break;

	case DVACT_DEACTIVATE:
		if (sc->sc_hwflags & COM_HW_CONSOLE) {
			rv = EBUSY;
			break;
		}

		if (sc->disable != NULL && sc->enabled != 0) {
			(*sc->disable)(sc);
			sc->enabled = 0;
		}
		break;
	}
	splx(s);
	return (rv);
}

int
comopen(dev, flag, mode, p)
	dev_t dev;
	int flag, mode;
	struct proc *p;
{
	int unit = DEVUNIT(dev);
	struct com_softc *sc;
	bus_space_tag_t iot;
	bus_space_handle_t ioh;
	struct tty *tp;
	int s;
	int error = 0;
 
	if (unit >= com_cd.cd_ndevs)
		return ENXIO;
	sc = com_cd.cd_devs[unit];
	if (!sc)
		return ENXIO;

	s = spltty();
	if (!sc->sc_tty) {
		tp = sc->sc_tty = ttymalloc();
		tty_attach(tp);
	} else
		tp = sc->sc_tty;
	splx(s);

	tp->t_oproc = comstart;