File:  [DragonFly] / src / sys / dev / usbmisc / ucom / ucom.c
Revision 1.15: download - view: text, annotated - select for diffs
Wed May 19 22:52:51 2004 UTC (10 years, 4 months ago) by dillon
Branches: MAIN
CVS tags: HEAD
Device layer rollup commit.

* cdevsw_add() is now required.  cdevsw_add() and cdevsw_remove() may specify
  a mask/match indicating the range of supported minor numbers.  Multiple
  cdevsw_add()'s using the same major number, but distinctly different
  ranges, may be issued.  All devices that failed to call cdevsw_add() before
  now do.

* cdevsw_remove() now automatically marks all devices within its supported
  range as being destroyed.

* vnode->v_rdev is no longer resolved when the vnode is created.  Instead,
  only v_udev (a newly added field) is resolved.  v_rdev is resolved when
  the vnode is opened and cleared on the last close.

* A great deal of code was making rather dubious assumptions with regards
  to the validity of devices associated with vnodes, primarily due to
  the persistence of a device structure due to being indexed by (major, minor)
  instead of by (cdevsw, major, minor).  In particular, if you run a program
  which connects to a USB device and then you pull the USB device and plug
  it back in, the vnode subsystem will continue to believe that the device
  is open when, in fact, it isn't (because it was destroyed and recreated).

  In particular, note that all the VFS mount procedures now check devices
  via v_udev instead of v_rdev prior to calling VOP_OPEN(), since v_rdev
  is NULL prior to the first open.

* The disk layer's device interaction has been rewritten.  The disk layer
  (i.e. the slice and disklabel management layer) no longer overloads
  its data onto the device structure representing the underlying physical
  disk.  Instead, the disk layer uses the new cdevsw_add() functionality
  to register its own cdevsw using the underlying device's major number,
  and simply does NOT register the underlying device's cdevsw.  No
  confusion is created because the device hash is now based on
  (cdevsw,major,minor) rather then (major,minor).

  NOTE: This also means that underlying raw disk devices may use the entire
  device minor number instead of having to reserve the bits used by the disk
  layer, and also means that can we (theoretically) stack a fully
  disklabel-supported 'disk' on top of any block device.

* The new reference counting scheme prevents this by associating a device
  with a cdevsw and disconnecting the device from its cdevsw when the cdevsw
  is removed.  Additionally, all udev2dev() lookups run through the cdevsw
  mask/match and only successfully find devices still associated with an
  active cdevsw.

* Major work on MFS:  MFS no longer shortcuts vnode and device creation.  It
  now creates a real vnode and a real device and implements real open and
  close VOPs.  Additionally, due to the disk layer changes, MFS is no longer
  limited to 255 mounts.  The new limit is 16 million.  Since MFS creates a
  real device node, mount_mfs will now create a real /dev/mfs<PID> device
  that can be read from userland (e.g. so you can dump an MFS filesystem).

* BUF AND DEVICE STRATEGY changes.  The struct buf contains a b_dev field.
  In order to properly handle stacked devices we now require that the b_dev
  field be initialized before the device strategy routine is called.  This
  required some additional work in various VFS implementations.  To enforce
  this requirement, biodone() now sets b_dev to NODEV.  The new disk layer
  will adjust b_dev before forwarding a request to the actual physical
  device.

* A bug in the ISO CD boot sequence which resulted in a panic has been fixed.

Testing by: lots of people, but David Rhodus found the most aggregious bugs.

/*
 * $NetBSD: ucom.c,v 1.39 2001/08/16 22:31:24 augustss Exp $
 * $NetBSD: ucom.c,v 1.40 2001/11/13 06:24:54 lukem Exp $
 * $FreeBSD: src/sys/dev/usb/ucom.c,v 1.35 2003/11/16 11:58:21 akiyama Exp $
 * $DragonFly: src/sys/dev/usbmisc/ucom/ucom.c,v 1.15 2004/05/19 22:52:51 dillon Exp $
 */
/*-
 * Copyright (c) 2001-2002, Shunsuke Akiyama <akiyama@jp.FreeBSD.org>.
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
 */

/*
 * Copyright (c) 1998, 2000 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Lennart Augustsson (lennart@augustsson.net) at
 * Carlstedt Research & Technology.
 *
 * 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 NetBSD
 *        Foundation, Inc. and its contributors.
 * 4. Neither the name of The NetBSD Foundation 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
 */

/*
 * TODO:
 * 1. How do I handle hotchar?
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/bus.h>
#include <sys/ioccom.h>
#include <sys/fcntl.h>
#include <sys/conf.h>
#include <sys/tty.h>
#include <sys/clist.h>
#include <sys/file.h>
#if defined(__FreeBSD__) && __FreeBSD_version >= 500014
#include <sys/selinfo.h>
#else
#include <sys/select.h>
#endif
#include <sys/proc.h>
#include <sys/vnode.h>
#include <sys/poll.h>
#include <sys/sysctl.h>

#include <bus/usb/usb.h>
#include <bus/usb/usbcdc.h>

#include <bus/usb/usbdi.h>
#include <bus/usb/usbdi_util.h>
#include <bus/usb/usbdevs.h>
#include <bus/usb/usb_quirks.h>

#include "ucomvar.h"

#ifdef USB_DEBUG
static int	ucomdebug = 0;
SYSCTL_NODE(_hw_usb, OID_AUTO, ucom, CTLFLAG_RW, 0, "USB ucom");
SYSCTL_INT(_hw_usb_ucom, OID_AUTO, debug, CTLFLAG_RW,
	   &ucomdebug, 0, "ucom debug level");
#define DPRINTF(x)	do { \
				if (ucomdebug) \
					logprintf x; \
			} while (0)

#define DPRINTFN(n, x)	do { \
				if (ucomdebug > (n)) \
					logprintf x; \
			} while (0)
#else
#define DPRINTF(x)
#define DPRINTFN(n, x)
#endif

Static d_open_t  ucomopen;
Static d_close_t ucomclose;
Static d_read_t  ucomread;
Static d_write_t ucomwrite;
Static d_ioctl_t ucomioctl;

#define UCOM_CDEV_MAJOR  138

static struct cdevsw ucom_cdevsw = {
	/* name */      "ucom",
	/* maj */       UCOM_CDEV_MAJOR,
	/* flags */     D_TTY | D_KQFILTER,
	/* port */	NULL,
	/* clone */	NULL,

	/* open */      ucomopen,
	/* close */     ucomclose,
	/* read */      ucomread,
	/* write */     ucomwrite,
	/* ioctl */     ucomioctl,
	/* poll */      ttypoll,
	/* mmap */      nommap,
	/* strategy */  nostrategy,
	/* dump */      nodump,
	/* psize */     nopsize,
	/* kqfilter */	ttykqfilter
};

Static void ucom_cleanup(struct ucom_softc *);
Static int ucomctl(struct ucom_softc *, int, int);
Static int ucomparam(struct tty *, struct termios *);
Static void ucomstart(struct tty *);
Static void ucomstop(struct tty *, int);
Static void ucom_shutdown(struct ucom_softc *);
Static void ucom_dtr(struct ucom_softc *, int);
Static void ucom_rts(struct ucom_softc *, int);
Static void ucom_break(struct ucom_softc *, int);
Static usbd_status ucomstartread(struct ucom_softc *);
Static void ucomreadcb(usbd_xfer_handle, usbd_private_handle, usbd_status);
Static void ucomwritecb(usbd_xfer_handle, usbd_private_handle, usbd_status);
Static void ucomstopread(struct ucom_softc *);
static void disc_optim(struct tty *, struct termios *, struct ucom_softc *);

devclass_t ucom_devclass;

static moduledata_t ucom_mod = {
	"ucom",
	NULL,
	NULL
};

DECLARE_MODULE(ucom, ucom_mod, SI_SUB_DRIVERS, SI_ORDER_MIDDLE);
MODULE_DEPEND(ucom, usb, 1, 1, 1);
MODULE_VERSION(ucom, UCOM_MODVER);

int
ucom_attach(struct ucom_softc *sc)
{
	struct tty *tp;
	int unit;
	dev_t dev;

	unit = device_get_unit(sc->sc_dev);

	sc->sc_tty = tp = ttymalloc(sc->sc_tty);
	tp->t_oproc = ucomstart;
	tp->t_param = ucomparam;
	tp->t_stop = ucomstop;

	DPRINTF(("ucom_attach: tty_attach tp = %p\n", tp));

	DPRINTF(("ucom_attach: make_dev: ucom%d\n", unit));

	cdevsw_add(&ucom_cdevsw, UCOMUNIT_MASK, unit);
	dev = make_dev(&ucom_cdevsw, unit | UCOM_CALLOUT_MASK,
			UID_UUCP, GID_DIALER, 0660,
			"ucom%d", unit);
	dev->si_tty = tp;

	return (0);
}

int
ucom_detach(struct ucom_softc *sc)
{
	struct tty *tp = sc->sc_tty;
	int s;
	int unit;

	DPRINTF(("ucom_detach: sc = %p, tp = %p\n", sc, sc->sc_tty));

	sc->sc_dying = 1;

	if (sc->sc_bulkin_pipe != NULL)
		usbd_abort_pipe(sc->sc_bulkin_pipe);
	if (sc->sc_bulkout_pipe != NULL)
		usbd_abort_pipe(sc->sc_bulkout_pipe);

	if (tp != NULL) {
		if (tp->t_state & TS_ISOPEN) {
			device_printf(sc->sc_dev,
				      "still open, forcing close\n");
			(*linesw[tp->t_line].l_close)(tp, 0);
			tp->t_gen++;
			ttyclose(tp);
			ttwakeup(tp);
			ttwwakeup(tp);
		}
	} else {
		DPRINTF(("ucom_detach: no tty\n"));
		return (0);
	}

	s = splusb();
	if (--sc->sc_refcnt >= 0) {
		/* Wait for processes to go away. */
		usb_detach_wait(USBDEV(sc->sc_dev));
	}
	splx(s);

	unit = device_get_unit(sc->sc_dev);
	cdevsw_remove(&ucom_cdevsw, UCOMUNIT_MASK, unit);

	return (0);
}

Static void
ucom_shutdown(struct ucom_softc *sc)
{
	struct tty *tp = sc->sc_tty;

	DPRINTF(("ucom_shutdown\n"));
	/*
	 * Hang up if necessary.  Wait a bit, so the other side has time to
	 * notice even if we immediately open the port again.
	 */
	if (ISSET(tp->t_cflag, HUPCL)) {
		(void)ucomctl(sc, TIOCM_DTR, DMBIC);
		(void)tsleep(sc, 0, "ucomsd", hz);
	}
}

Static int
ucomopen(dev_t dev, int flag, int mode, usb_proc_ptr td)
{
	int unit = UCOMUNIT(dev);
	struct ucom_softc *sc;
	usbd_status err;
	struct tty *tp;
	int s;
	int error;

	KKASSERT(td != NULL);

	USB_GET_SC_OPEN(ucom, unit, sc);

	if (sc->sc_dying)
		return (ENXIO);

	tp = sc->sc_tty;

	DPRINTF(("%s: ucomopen: tp = %p\n", USBDEVNAME(sc->sc_dev), tp));

	if (ISSET(tp->t_state, TS_ISOPEN) &&
	    ISSET(tp->t_state, TS_XCLUDE) &&
	    suser(td)
	) {
		return (EBUSY);
	}

	/*
	 * Do the following iff this is a first open.
	 */
	s = spltty();
	while (sc->sc_opening)
		tsleep(&sc->sc_opening, 0, "ucomop", 0);
	sc->sc_opening = 1;

	if (!ISSET(tp->t_state, TS_ISOPEN)) {
		struct termios t;

		sc->sc_poll = 0;
		sc->sc_lsr = sc->sc_msr = sc->sc_mcr = 0;

		tp->t_dev = reference_dev(dev);

		/*
		 * Initialize the termios status to the defaults.  Add in the
		 * sticky bits from TIOCSFLAGS.
		 */
		t.c_ispeed = 0;
		t.c_ospeed = TTYDEF_SPEED;
		t.c_cflag = TTYDEF_CFLAG;
		/* Make sure ucomparam() will do something. */
		tp->t_ospeed = 0;
		(void)ucomparam(tp, &t);
		tp->t_iflag = TTYDEF_IFLAG;
		tp->t_oflag = TTYDEF_OFLAG;
		tp->t_lflag = TTYDEF_LFLAG;
		ttychars(tp);
		ttsetwater(tp);

		/*
		 * Turn on DTR.  We must always do this, even if carrier is not
		 * present, because otherwise we'd have to use TIOCSDTR
		 * immediately after setting CLOCAL, which applications do not
		 * expect.  We always assert DTR while the device is open
		 * unless explicitly requested to deassert it.
		 */
		(void)ucomctl(sc, TIOCM_DTR | TIOCM_RTS, DMBIS);

		/* Device specific open */
		if (sc->sc_callback->ucom_open != NULL) {
			error = sc->sc_callback->ucom_open(sc->sc_parent,
							   sc->sc_portno);
			if (error) {
				ucom_cleanup(sc);
				sc->sc_opening = 0;
				wakeup(&sc->sc_opening);
				splx(s);
				return (error);
			}
		}

		DPRINTF(("ucomopen: open pipes in = %d out = %d\n",
			 sc->sc_bulkin_no, sc->sc_bulkout_no));

		/* Open the bulk pipes */
		/* Bulk-in pipe */
		err = usbd_open_pipe(sc->sc_iface, sc->sc_bulkin_no, 0,
				     &sc->sc_bulkin_pipe);
		if (err) {
			printf("%s: open bulk in error (addr %d): %s\n",
			       USBDEVNAME(sc->sc_dev), sc->sc_bulkin_no,
			       usbd_errstr(err));
			error = EIO;
			goto fail_0;
		}
		/* Bulk-out pipe */
		err = usbd_open_pipe(sc->sc_iface, sc->sc_bulkout_no,
				     USBD_EXCLUSIVE_USE, &sc->sc_bulkout_pipe);
		if (err) {
			printf("%s: open bulk out error (addr %d): %s\n",
			       USBDEVNAME(sc->sc_dev), sc->sc_bulkout_no,
			       usbd_errstr(err));
			error = EIO;
			goto fail_1;
		}

		/* Allocate a request and an input buffer and start reading. */
		sc->sc_ixfer = usbd_alloc_xfer(sc->sc_udev);
		if (sc->sc_ixfer == NULL) {
			error = ENOMEM;
			goto fail_2;
		}

		sc->sc_ibuf = usbd_alloc_buffer(sc->sc_ixfer,
						sc->sc_ibufsizepad);
		if (sc->sc_ibuf == NULL) {
			error = ENOMEM;
			goto fail_3;
		}

		sc->sc_oxfer = usbd_alloc_xfer(sc->sc_udev);
		if (sc->sc_oxfer == NULL) {
			error = ENOMEM;
			goto fail_3;
		}

		sc->sc_obuf = usbd_alloc_buffer(sc->sc_oxfer,
						sc->sc_obufsize +
						sc->sc_opkthdrlen);
		if (sc->sc_obuf == NULL) {
			error = ENOMEM;
			goto fail_4;
		}

		/*
		 * Handle initial DCD.
		 */
		if (ISSET(sc->sc_msr, UMSR_DCD) ||
		    (minor(dev) & UCOM_CALLOUT_MASK))
			(*linesw[tp->t_line].l_modem)(tp, 1);

		ucomstartread(sc);
	}

	sc->sc_opening = 0;
	wakeup(&sc->sc_opening);
	splx(s);

	error = ttyopen(dev, tp);
	if (error)
		goto bad;

	error = (*linesw[tp->t_line].l_open)(dev, tp);
	if (error)
		goto bad;

	disc_optim(tp, &tp->t_termios, sc);

	DPRINTF(("%s: ucomopen: success\n", USBDEVNAME(sc->sc_dev)));

	sc->sc_poll = 1;
	sc->sc_refcnt++;

	return (0);

fail_4:
	usbd_free_xfer(sc->sc_oxfer);
	sc->sc_oxfer = NULL;
fail_3:
	usbd_free_xfer(sc->sc_ixfer);
	sc->sc_ixfer = NULL;
fail_2:
	usbd_close_pipe(sc->sc_bulkout_pipe);
	sc->sc_bulkout_pipe = NULL;
fail_1:
	usbd_close_pipe(sc->sc_bulkin_pipe);
	sc->sc_bulkin_pipe = NULL;
fail_0:
	sc->sc_opening = 0;
	wakeup(&sc->sc_opening);
	splx(s);
	return (error);

bad:
	if (!ISSET(tp->t_state, TS_ISOPEN)) {
		/*
		 * We failed to open the device, and nobody else had it opened.
		 * Clean up the state as appropriate.
		 */
		ucom_cleanup(sc);
	}

	DPRINTF(("%s: ucomopen: failed\n", USBDEVNAME(sc->sc_dev)));

	return (error);
}

static int
ucomclose(dev_t dev, int flag, int mode, usb_proc_ptr p)
{
	struct ucom_softc *sc;
	struct tty *tp;
	int s;

	USB_GET_SC(ucom, UCOMUNIT(dev), sc);

	tp = sc->sc_tty;

	DPRINTF(("%s: ucomclose: unit = %d\n",
		USBDEVNAME(sc->sc_dev), UCOMUNIT(dev)));

	if (tp->t_dev) {
		release_dev(tp->t_dev);
		tp->t_dev = NULL;
	}

	if (!ISSET(tp->t_state, TS_ISOPEN))
		goto quit;

	s = spltty();
	(*linesw[tp->t_line].l_close)(tp, flag);
	disc_optim(tp, &tp->t_termios, sc);
	ttyclose(tp);
	splx(s);

	if (sc->sc_dying)
		goto quit;

	if (!ISSET(tp->t_state, TS_ISOPEN)) {
		/*
		 * Although we got a last close, the device may still be in
		 * use; e.g. if this was the dialout node, and there are still
		 * processes waiting for carrier on the non-dialout node.
		 */
		ucom_cleanup(sc);
	}

	if (sc->sc_callback->ucom_close != NULL)
		sc->sc_callback->ucom_close(sc->sc_parent, sc->sc_portno);

    quit:
	if (--sc->sc_refcnt < 0)
		usb_detach_wakeup(USBDEV(sc->sc_dev));

	return (0);
}

static int
ucomread(dev_t dev, struct uio *uio, int flag)
{
	struct ucom_softc *sc;
	struct tty *tp;
	int error;

	USB_GET_SC(ucom, UCOMUNIT(dev), sc);
	tp = sc->sc_tty;

	DPRINTF(("ucomread: tp = %p, flag = 0x%x\n", tp, flag));

	if (sc->sc_dying)
		return (EIO);

	error = (*linesw[tp->t_line].l_read)(tp, uio, flag);

	DPRINTF(("ucomread: error = %d\n", error));

	return (error);
}

static int
ucomwrite(dev_t dev, struct uio *uio, int flag)
{
	struct ucom_softc *sc;
	struct tty *tp;
	int error;

	USB_GET_SC(ucom, UCOMUNIT(dev), sc);
	tp = sc->sc_tty;

	DPRINTF(("ucomwrite: tp = %p, flag = 0x%x\n", tp, flag));

	if (sc->sc_dying)
		return (EIO);

	error = (*linesw[tp->t_line].l_write)(tp, uio, flag);

	DPRINTF(("ucomwrite: error = %d\n", error));

	return (error);
}

static int
ucomioctl(dev_t dev, u_long cmd, caddr_t data, int flag, usb_proc_ptr p)
{
	struct ucom_softc *sc;
	struct tty *tp;
	int error;
	int s;
	int d;

	USB_GET_SC(ucom, UCOMUNIT(dev), sc);
	tp = sc->sc_tty;

	if (sc->sc_dying)
		return (EIO);

	DPRINTF(("ucomioctl: cmd = 0x%08lx\n", cmd));

	error = (*linesw[tp->t_line].l_ioctl)(tp, cmd, data, flag, p);
	if (error != ENOIOCTL) {
		DPRINTF(("ucomioctl: l_ioctl: error = %d\n", error));
		return (error);
	}

	s = spltty();

	error = ttioctl(tp, cmd, data, flag);
	disc_optim(tp, &tp->t_termios, sc);
	if (error != ENOIOCTL) {
		splx(s);
		DPRINTF(("ucomioctl: ttioctl: error = %d\n", error));
		return (error);
	}

	if (sc->sc_callback->ucom_ioctl != NULL) {
		/* XXX splx(s) ? */
		error = sc->sc_callback->ucom_ioctl(sc->sc_parent,
						    sc->sc_portno,
						    cmd, data, flag, p);
		if (error >= 0)
			return (error);
	}

	error = 0;

	DPRINTF(("ucomioctl: our cmd = 0x%08lx\n", cmd));

	switch (cmd) {
	case TIOCSBRK:
		DPRINTF(("ucomioctl: TIOCSBRK\n"));
		ucom_break(sc, 1);
		break;
	case TIOCCBRK:
		DPRINTF(("ucomioctl: TIOCCBRK\n"));
		ucom_break(sc, 0);
		break;

	case TIOCSDTR:
		DPRINTF(("ucomioctl: TIOCSDTR\n"));
		(void)ucomctl(sc, TIOCM_DTR, DMBIS);
		break;
	case TIOCCDTR:
		DPRINTF(("ucomioctl: TIOCCDTR\n"));
		(void)ucomctl(sc, TIOCM_DTR, DMBIC);
		break;

	case TIOCMSET:
		d = *(int *)data;
		DPRINTF(("ucomioctl: TIOCMSET, 0x%x\n", d));
		(void)ucomctl(sc, d, DMSET);
		break;
	case TIOCMBIS:
		d = *(int *)data;
		DPRINTF(("ucomioctl: TIOCMBIS, 0x%x\n", d));
		(void)ucomctl(sc, d, DMBIS);
		break;
	case TIOCMBIC:
		d = *(int *)data;
		DPRINTF(("ucomioctl: TIOCMBIC, 0x%x\n", d));
		(void)ucomctl(sc, d, DMBIC);
		break;
	case TIOCMGET:
		d = ucomctl(sc, 0, DMGET);
		DPRINTF(("ucomioctl: TIOCMGET, 0x%x\n", d));
		*(int *)data = d;
		break;

	default:
		DPRINTF(("ucomioctl: error: our cmd = 0x%08lx\n", cmd));
		error = ENOTTY;
		break;
	}

	splx(s);

	return (error);
}

Static int
ucomctl(struct ucom_softc *sc, int bits, int how)
{
	int	mcr;
	int	msr;
	int	onoff;

	DPRINTF(("ucomctl: bits = 0x%x, how = %d\n", bits, how));

	if (how == DMGET) {
		SET(bits, TIOCM_LE);		/* always set TIOCM_LE bit */
		DPRINTF(("ucomctl: DMGET: LE"));

		mcr = sc->sc_mcr;
		if (ISSET(mcr, UMCR_DTR)) {
			SET(bits, TIOCM_DTR);
			DPRINTF((" DTR"));
		}
		if (ISSET(mcr, UMCR_RTS)) {
			SET(bits, TIOCM_RTS);
			DPRINTF((" RTS"));
		}

		msr = sc->sc_msr;
		if (ISSET(msr, UMSR_CTS)) {
			SET(bits, TIOCM_CTS);
			DPRINTF((" CTS"));
		}
		if (ISSET(msr, UMSR_DCD)) {
			SET(bits, TIOCM_CD);
			DPRINTF((" CD"));
		}
		if (ISSET(msr, UMSR_DSR)) {
			SET(bits, TIOCM_DSR);
			DPRINTF((" DSR"));
		}
		if (ISSET(msr, UMSR_RI)) {
			SET(bits, TIOCM_RI);
			DPRINTF((" RI"));
		}

		DPRINTF(("\n"));

		return (bits);
	}

	mcr = 0;
	if (ISSET(bits, TIOCM_DTR))
		SET(mcr, UMCR_DTR);
	if (ISSET(bits, TIOCM_RTS))
		SET(mcr, UMCR_RTS);

	switch (how) {
	case DMSET:
		sc->sc_mcr = mcr;
		break;
	case DMBIS:
		sc->sc_mcr |= mcr;
		break;
	case DMBIC:
		sc->sc_mcr &= ~mcr;
		break;
	}

	onoff = ISSET(sc->sc_mcr, UMCR_DTR) ? 1 : 0;
	ucom_dtr(sc, onoff);

	onoff = ISSET(sc->sc_mcr, UMCR_RTS) ? 1 : 0;
	ucom_rts(sc, onoff);

	return (0);
}

Static void
ucom_break(struct ucom_softc *sc, int onoff)
{
	DPRINTF(("ucom_break: onoff = %d\n", onoff));

	if (sc->sc_callback->ucom_set == NULL)
		return;
	sc->sc_callback->ucom_set(sc->sc_parent, sc->sc_portno,
				  UCOM_SET_BREAK, onoff);
}

Static void
ucom_dtr(struct ucom_softc *sc, int onoff)
{
	DPRINTF(("ucom_dtr: onoff = %d\n", onoff));

	if (sc->sc_callback->ucom_set == NULL)
		return;
	sc->sc_callback->ucom_set(sc->sc_parent, sc->sc_portno,
				  UCOM_SET_DTR, onoff);
}

Static void
ucom_rts(struct ucom_softc *sc, int onoff)
{
	DPRINTF(("ucom_rts: onoff = %d\n", onoff));

	if (sc->sc_callback->ucom_set == NULL)
		return;
	sc->sc_callback->ucom_set(sc->sc_parent, sc->sc_portno,
				  UCOM_SET_RTS, onoff);
}

void
ucom_status_change(struct ucom_softc *sc)
{
	struct tty *tp = sc->sc_tty;
	u_char old_msr;
	int onoff;

	if (sc->sc_callback->ucom_get_status == NULL) {
		sc->sc_lsr = 0;
		sc->sc_msr = 0;
		return;
	}

	old_msr = sc->sc_msr;
	sc->sc_callback->ucom_get_status(sc->sc_parent, sc->sc_portno,
					 &sc->sc_lsr, &sc->sc_msr);
	if (ISSET((sc->sc_msr ^ old_msr), UMSR_DCD)) {
		if (sc->sc_poll == 0)
			return;
		onoff = ISSET(sc->sc_msr, UMSR_DCD) ? 1 : 0;
		DPRINTF(("ucom_status_change: DCD changed to %d\n", onoff));
		(*linesw[tp->t_line].l_modem)(tp, onoff);
	}
}

Static int
ucomparam(struct tty *tp, struct termios *t)
{
	struct ucom_softc *sc;
	int error;
	usbd_status uerr;

	USB_GET_SC(ucom, UCOMUNIT(tp->t_dev), sc);

	if (sc->sc_dying)
		return (EIO);

	DPRINTF(("ucomparam: sc = %p\n", sc));

	/* Check requested parameters. */
	if (t->c_ospeed < 0) {
		DPRINTF(("ucomparam: negative ospeed\n"));
		return (EINVAL);
	}
	if (t->c_ispeed && t->c_ispeed != t->c_ospeed) {
		DPRINTF(("ucomparam: mismatch ispeed and ospeed\n"));
		return (EINVAL);
	}

	/*
	 * If there were no changes, don't do anything.  This avoids dropping
	 * input and improves performance when all we did was frob things like
	 * VMIN and VTIME.
	 */
	if (tp->t_ospeed == t->c_ospeed &&
	    tp->t_cflag == t->c_cflag)
		return (0);

	/* And copy to tty. */
	tp->t_ispeed = 0;
	tp->t_ospeed = t->c_ospeed;
	tp->t_cflag = t->c_cflag;

	if (sc->sc_callback->ucom_param == NULL)
		return (0);

	ucomstopread(sc);

	error = sc->sc_callback->ucom_param(sc->sc_parent, sc->sc_portno, t);
	if (error) {
		DPRINTF(("ucomparam: callback: error = %d\n", error));
		return (error);
	}

	ttsetwater(tp);

	if (t->c_cflag & CRTS_IFLOW) {
		sc->sc_state |= UCS_RTS_IFLOW;
	} else if (sc->sc_state & UCS_RTS_IFLOW) {
		sc->sc_state &= ~UCS_RTS_IFLOW;
		(void)ucomctl(sc, UMCR_RTS, DMBIS);
	}

	disc_optim(tp, t, sc);

	uerr = ucomstartread(sc);
	if (uerr != USBD_NORMAL_COMPLETION)
		return (EIO);

	return (0);
}

Static void
ucomstart(struct tty *tp)
{
	struct ucom_softc *sc;
	struct cblock *cbp;
	usbd_status err;
	int s;
	u_char *data;
	int cnt;

	USB_GET_SC(ucom, UCOMUNIT(tp->t_dev), sc);
	DPRINTF(("ucomstart: sc = %p\n", sc));

	if (sc->sc_dying)
		return;

	s = spltty();

	if (tp->t_state & TS_TBLOCK) {
		if (ISSET(sc->sc_mcr, UMCR_RTS) &&
		    ISSET(sc->sc_state, UCS_RTS_IFLOW)) {
			DPRINTF(("ucomstart: clear RTS\n"));
			(void)ucomctl(sc, UMCR_RTS, DMBIC);
		}
	} else {
		if (!ISSET(sc->sc_mcr, UMCR_RTS) &&
		    tp->t_rawq.c_cc <= tp->t_ilowat &&
		    ISSET(sc->sc_state, UCS_RTS_IFLOW)) {
			DPRINTF(("ucomstart: set RTS\n"));
			(void)ucomctl(sc, UMCR_RTS, DMBIS);
		}
	}

	if (ISSET(tp->t_state, TS_BUSY | TS_TIMEOUT | TS_TTSTOP)) {
		ttwwakeup(tp);
		DPRINTF(("ucomstart: stopped\n"));
		goto out;
	}

	if (tp->t_outq.c_cc <= tp->t_olowat) {
		if (ISSET(tp->t_state, TS_SO_OLOWAT)) {
			CLR(tp->t_state, TS_SO_OLOWAT);
			wakeup(TSA_OLOWAT(tp));
		}
		selwakeuppri(&tp->t_wsel, TTIPRI);
		if (tp->t_outq.c_cc == 0) {
			if (ISSET(tp->t_state, TS_BUSY | TS_SO_OCOMPLETE) ==
			    TS_SO_OCOMPLETE && tp->t_outq.c_cc == 0) {
				CLR(tp->t_state, TS_SO_OCOMPLETE);
				wakeup(TSA_OCOMPLETE(tp));
			}
			goto out;
		}
	}

	/* Grab the first contiguous region of buffer space. */
	data = tp->t_outq.c_cf;
	cbp = (struct cblock *) ((intptr_t) tp->t_outq.c_cf & ~CROUND);
	cnt = min((char *) (cbp+1) - tp->t_outq.c_cf, tp->t_outq.c_cc);

	if (cnt == 0) {
		DPRINTF(("ucomstart: cnt == 0\n"));
		goto out;
	}

	SET(tp->t_state, TS_BUSY);

	if (cnt > sc->sc_obufsize) {
		DPRINTF(("ucomstart: big buffer %d chars\n", cnt));
		cnt = sc->sc_obufsize;
	}
	if (sc->sc_callback->ucom_write != NULL)
		sc->sc_callback->ucom_write(sc->sc_parent, sc->sc_portno,
					    sc->sc_obuf, data, &cnt);
	else
		memcpy(sc->sc_obuf, data, cnt);

	DPRINTF(("ucomstart: %d chars\n", cnt));
	usbd_setup_xfer(sc->sc_oxfer, sc->sc_bulkout_pipe,
			(usbd_private_handle)sc, sc->sc_obuf, cnt,
			USBD_NO_COPY, USBD_NO_TIMEOUT, ucomwritecb);
	/* What can we do on error? */
	err = usbd_transfer(sc->sc_oxfer);
	if (err != USBD_IN_PROGRESS)
		printf("ucomstart: err=%s\n", usbd_errstr(err));

	ttwwakeup(tp);

    out:
	splx(s);
}

Static void
ucomstop(struct tty *tp, int flag)
{
	struct ucom_softc *sc;
	int s;

	USB_GET_SC(ucom, UCOMUNIT(tp->t_dev), sc);

	DPRINTF(("ucomstop: %d\n", flag));

	if (flag & FREAD) {
		DPRINTF(("ucomstop: read\n"));
		ucomstopread(sc);
	}

	if (flag & FWRITE) {
		DPRINTF(("ucomstop: write\n"));
		s = spltty();
		if (ISSET(tp->t_state, TS_BUSY)) {
			/* XXX do what? */
			if (!ISSET(tp->t_state, TS_TTSTOP))
				SET(tp->t_state, TS_FLUSH);
		}
		splx(s);
	}

	DPRINTF(("ucomstop: done\n"));
}

Static void
ucomwritecb(usbd_xfer_handle xfer, usbd_private_handle p, usbd_status status)
{
	struct ucom_softc *sc = (struct ucom_softc *)p;
	struct tty *tp = sc->sc_tty;
	u_int32_t cc;
	int s;

	DPRINTF(("ucomwritecb: status = %d\n", status));

	if (status == USBD_CANCELLED || sc->sc_dying)
		goto error;

	if (status != USBD_NORMAL_COMPLETION) {
		printf("%s: ucomwritecb: %s\n",
		       USBDEVNAME(sc->sc_dev), usbd_errstr(status));
		if (status == USBD_STALLED)
			usbd_clear_endpoint_stall_async(sc->sc_bulkin_pipe);
		/* XXX we should restart after some delay. */
		goto error;
	}

	usbd_get_xfer_status(xfer, NULL, NULL, &cc, NULL);
	DPRINTF(("ucomwritecb: cc = %d\n", cc));
	if (cc <= sc->sc_opkthdrlen) {
		printf("%s: sent size too small, cc = %d\n",
			USBDEVNAME(sc->sc_dev), cc);
		goto error;
	}

	/* convert from USB bytes to tty bytes */
	cc -= sc->sc_opkthdrlen;

	s = spltty();
	CLR(tp->t_state, TS_BUSY);
	if (ISSET(tp->t_state, TS_FLUSH))
		CLR(tp->t_state, TS_FLUSH);
	else
		ndflush(&tp->t_outq, cc);
	(*linesw[tp->t_line].l_start)(tp);
	splx(s);

	return;

  error:
	s = spltty();
	CLR(tp->t_state, TS_BUSY);
	splx(s);
	return;
}

Static usbd_status
ucomstartread(struct ucom_softc *sc)
{
	usbd_status err;

	DPRINTF(("ucomstartread: start\n"));

	sc->sc_state &= ~UCS_RXSTOP;

	if (sc->sc_bulkin_pipe == NULL)
		return (USBD_NORMAL_COMPLETION);

	usbd_setup_xfer(sc->sc_ixfer, sc->sc_bulkin_pipe,
			(usbd_private_handle)sc,
			sc->sc_ibuf, sc->sc_ibufsize,
			USBD_SHORT_XFER_OK | USBD_NO_COPY,
			USBD_NO_TIMEOUT, ucomreadcb);

	err = usbd_transfer(sc->sc_ixfer);
	if (err != USBD_IN_PROGRESS) {
		DPRINTF(("ucomstartread: err = %s\n", usbd_errstr(err)));
		return (err);
	}

	return (USBD_NORMAL_COMPLETION);
}

Static void
ucomreadcb(usbd_xfer_handle xfer, usbd_private_handle p, usbd_status status)
{
	struct ucom_softc *sc = (struct ucom_softc *)p;
	struct tty *tp = sc->sc_tty;
	int (*rint) (int c, struct tty *tp) = linesw[tp->t_line].l_rint;
	usbd_status err;
	u_int32_t cc;
	u_char *cp;
	int lostcc;
	int s;

	DPRINTF(("ucomreadcb: status = %d\n", status));

	if (status != USBD_NORMAL_COMPLETION) {
		if (!(sc->sc_state & UCS_RXSTOP))
			printf("%s: ucomreadcb: %s\n",
			       USBDEVNAME(sc->sc_dev), usbd_errstr(status));
		if (status == USBD_STALLED)
			usbd_clear_endpoint_stall_async(sc->sc_bulkin_pipe);
		/* XXX we should restart after some delay. */
		return;
	}

	usbd_get_xfer_status(xfer, NULL, (void **)&cp, &cc, NULL);
	DPRINTF(("ucomreadcb: got %d chars, tp = %p\n", cc, tp));
	if (cc == 0)
		goto resubmit;

	if (sc->sc_callback->ucom_read != NULL) {
		sc->sc_callback->ucom_read(sc->sc_parent, sc->sc_portno,
					   &cp, &cc);
	}

	if (cc > sc->sc_ibufsize) {
		printf("%s: invalid receive data size, %d chars\n",
			USBDEVNAME(sc->sc_dev), cc);
		goto resubmit;
	}
	if (cc < 1)
		goto resubmit;

	s = spltty();
	if (tp->t_state & TS_CAN_BYPASS_L_RINT) {
		if (tp->t_rawq.c_cc + cc > tp->t_ihiwat
		    && (sc->sc_state & UCS_RTS_IFLOW
			|| tp->t_iflag & IXOFF)
		    && !(tp->t_state & TS_TBLOCK))
			ttyblock(tp);
		lostcc = b_to_q((char *)cp, cc, &tp->t_rawq);
		tp->t_rawcc += cc;
		ttwakeup(tp);
		if (tp->t_state & TS_TTSTOP
		    && (tp->t_iflag & IXANY
			|| tp->t_cc[VSTART] == tp->t_cc[VSTOP])) {
			tp->t_state &= ~TS_TTSTOP;
			tp->t_lflag &= ~FLUSHO;
			ucomstart(tp);
		}
		if (lostcc > 0)
			printf("%s: lost %d chars\n", USBDEVNAME(sc->sc_dev),
			       lostcc);
	} else {
		/* Give characters to tty layer. */
		while (cc > 0) {
			DPRINTFN(7, ("ucomreadcb: char = 0x%02x\n", *cp));
			if ((*rint)(*cp, tp) == -1) {
				/* XXX what should we do? */
				printf("%s: lost %d chars\n",
				       USBDEVNAME(sc->sc_dev), cc);
				break;
			}
			cc--;
			cp++;
		}
	}
	splx(s);

resubmit:
	err = ucomstartread(sc);
	if (err) {
		printf("%s: read start failed\n", USBDEVNAME(sc->sc_dev));
		/* XXX what should we dow now? */
	}

	if ((sc->sc_state & UCS_RTS_IFLOW) && !ISSET(sc->sc_mcr, UMCR_RTS)
	    && !(tp->t_state & TS_TBLOCK))
		ucomctl(sc, UMCR_RTS, DMBIS);
}

Static void
ucom_cleanup(struct ucom_softc *sc)
{
	DPRINTF(("ucom_cleanup: closing pipes\n"));

	ucom_shutdown(sc);
	if (sc->sc_bulkin_pipe != NULL) {
		usbd_abort_pipe(sc->sc_bulkin_pipe);
		usbd_close_pipe(sc->sc_bulkin_pipe);
		sc->sc_bulkin_pipe = NULL;
	}
	if (sc->sc_bulkout_pipe != NULL) {
		usbd_abort_pipe(sc->sc_bulkout_pipe);
		usbd_close_pipe(sc->sc_bulkout_pipe);
		sc->sc_bulkout_pipe = NULL;
	}
	if (sc->sc_ixfer != NULL) {
		usbd_free_xfer(sc->sc_ixfer);
		sc->sc_ixfer = NULL;
	}
	if (sc->sc_oxfer != NULL) {
		usbd_free_xfer(sc->sc_oxfer);
		sc->sc_oxfer = NULL;
	}
}

Static void
ucomstopread(struct ucom_softc *sc)
{
	usbd_status err;

	DPRINTF(("ucomstopread: enter\n"));

	if (!(sc->sc_state & UCS_RXSTOP)) {
		sc->sc_state |= UCS_RXSTOP;
		if (sc->sc_bulkin_pipe == NULL) {
			DPRINTF(("ucomstopread: bulkin pipe NULL\n"));
			return;
		}
		err = usbd_abort_pipe(sc->sc_bulkin_pipe);
		if (err) {
			DPRINTF(("ucomstopread: err = %s\n",
				 usbd_errstr(err)));
		}
	}

	DPRINTF(("ucomstopread: leave\n"));
}

static void
disc_optim(struct tty *tp, struct termios *t, struct ucom_softc *sc)
{
	if (!(t->c_iflag & (ICRNL | IGNCR | IMAXBEL | INLCR | ISTRIP | IXON))
	    && (!(t->c_iflag & BRKINT) || (t->c_iflag & IGNBRK))
	    && (!(t->c_iflag & PARMRK)
		|| (t->c_iflag & (IGNPAR | IGNBRK)) == (IGNPAR | IGNBRK))
	    && !(t->c_lflag & (ECHO | ICANON | IEXTEN | ISIG | PENDIN))
	    && linesw[tp->t_line].l_rint == ttyinput) {
		DPRINTF(("disc_optim: bypass l_rint\n"));
		tp->t_state |= TS_CAN_BYPASS_L_RINT;
	} else {
		DPRINTF(("disc_optim: can't bypass l_rint\n"));
		tp->t_state &= ~TS_CAN_BYPASS_L_RINT;
	}
	sc->hotchar = linesw[tp->t_line].l_hotchar;
}