xref: /freebsd/sys/dev/usb/serial/usb_serial.c (revision 9a14aa017b21c292740c00ee098195cd46642730)
1 /*	$NetBSD: ucom.c,v 1.40 2001/11/13 06:24:54 lukem Exp $	*/
2 
3 /*-
4  * Copyright (c) 2001-2003, 2005, 2008
5  *	Shunsuke Akiyama <akiyama@jp.FreeBSD.org>.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 /*-
34  * Copyright (c) 1998, 2000 The NetBSD Foundation, Inc.
35  * All rights reserved.
36  *
37  * This code is derived from software contributed to The NetBSD Foundation
38  * by Lennart Augustsson (lennart@augustsson.net) at
39  * Carlstedt Research & Technology.
40  *
41  * Redistribution and use in source and binary forms, with or without
42  * modification, are permitted provided that the following conditions
43  * are met:
44  * 1. Redistributions of source code must retain the above copyright
45  *    notice, this list of conditions and the following disclaimer.
46  * 2. Redistributions in binary form must reproduce the above copyright
47  *    notice, this list of conditions and the following disclaimer in the
48  *    documentation and/or other materials provided with the distribution.
49  * 3. All advertising materials mentioning features or use of this software
50  *    must display the following acknowledgement:
51  *        This product includes software developed by the NetBSD
52  *        Foundation, Inc. and its contributors.
53  * 4. Neither the name of The NetBSD Foundation nor the names of its
54  *    contributors may be used to endorse or promote products derived
55  *    from this software without specific prior written permission.
56  *
57  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
58  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
59  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
60  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
61  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
62  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
63  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
64  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
65  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
66  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
67  * POSSIBILITY OF SUCH DAMAGE.
68  */
69 
70 #include <sys/stdint.h>
71 #include <sys/stddef.h>
72 #include <sys/param.h>
73 #include <sys/queue.h>
74 #include <sys/types.h>
75 #include <sys/systm.h>
76 #include <sys/kernel.h>
77 #include <sys/bus.h>
78 #include <sys/module.h>
79 #include <sys/lock.h>
80 #include <sys/mutex.h>
81 #include <sys/condvar.h>
82 #include <sys/sysctl.h>
83 #include <sys/sx.h>
84 #include <sys/unistd.h>
85 #include <sys/callout.h>
86 #include <sys/malloc.h>
87 #include <sys/priv.h>
88 #include <sys/cons.h>
89 #include <sys/kdb.h>
90 
91 #include <dev/usb/usb.h>
92 #include <dev/usb/usbdi.h>
93 #include <dev/usb/usbdi_util.h>
94 
95 #define	USB_DEBUG_VAR ucom_debug
96 #include <dev/usb/usb_debug.h>
97 #include <dev/usb/usb_busdma.h>
98 #include <dev/usb/usb_process.h>
99 
100 #include <dev/usb/serial/usb_serial.h>
101 
102 #include "opt_gdb.h"
103 
104 static SYSCTL_NODE(_hw_usb, OID_AUTO, ucom, CTLFLAG_RW, 0, "USB ucom");
105 
106 #ifdef USB_DEBUG
107 static int ucom_debug = 0;
108 
109 SYSCTL_INT(_hw_usb_ucom, OID_AUTO, debug, CTLFLAG_RW,
110     &ucom_debug, 0, "ucom debug level");
111 #endif
112 
113 #define	UCOM_CONS_BUFSIZE 1024
114 
115 static uint8_t ucom_cons_rx_buf[UCOM_CONS_BUFSIZE];
116 static uint8_t ucom_cons_tx_buf[UCOM_CONS_BUFSIZE];
117 
118 static unsigned int ucom_cons_rx_low = 0;
119 static unsigned int ucom_cons_rx_high = 0;
120 
121 static unsigned int ucom_cons_tx_low = 0;
122 static unsigned int ucom_cons_tx_high = 0;
123 
124 static int ucom_cons_unit = -1;
125 static int ucom_cons_subunit = 0;
126 static int ucom_cons_baud = 9600;
127 static struct ucom_softc *ucom_cons_softc = NULL;
128 
129 TUNABLE_INT("hw.usb.ucom.cons_unit", &ucom_cons_unit);
130 SYSCTL_INT(_hw_usb_ucom, OID_AUTO, cons_unit, CTLFLAG_RW,
131     &ucom_cons_unit, 0, "console unit number");
132 TUNABLE_INT("hw.usb.ucom.cons_subunit", &ucom_cons_subunit);
133 SYSCTL_INT(_hw_usb_ucom, OID_AUTO, cons_subunit, CTLFLAG_RW,
134     &ucom_cons_subunit, 0, "console subunit number");
135 TUNABLE_INT("hw.usb.ucom.cons_baud", &ucom_cons_baud);
136 SYSCTL_INT(_hw_usb_ucom, OID_AUTO, cons_baud, CTLFLAG_RW,
137     &ucom_cons_baud, 0, "console baud rate");
138 
139 static usb_proc_callback_t ucom_cfg_start_transfers;
140 static usb_proc_callback_t ucom_cfg_open;
141 static usb_proc_callback_t ucom_cfg_close;
142 static usb_proc_callback_t ucom_cfg_line_state;
143 static usb_proc_callback_t ucom_cfg_status_change;
144 static usb_proc_callback_t ucom_cfg_param;
145 
146 static int	ucom_unit_alloc(void);
147 static void	ucom_unit_free(int);
148 static int	ucom_attach_tty(struct ucom_super_softc *, struct ucom_softc *);
149 static void	ucom_detach_tty(struct ucom_softc *);
150 static void	ucom_queue_command(struct ucom_softc *,
151 		    usb_proc_callback_t *, struct termios *pt,
152 		    struct usb_proc_msg *t0, struct usb_proc_msg *t1);
153 static void	ucom_shutdown(struct ucom_softc *);
154 static void	ucom_ring(struct ucom_softc *, uint8_t);
155 static void	ucom_break(struct ucom_softc *, uint8_t);
156 static void	ucom_dtr(struct ucom_softc *, uint8_t);
157 static void	ucom_rts(struct ucom_softc *, uint8_t);
158 
159 static tsw_open_t ucom_open;
160 static tsw_close_t ucom_close;
161 static tsw_ioctl_t ucom_ioctl;
162 static tsw_modem_t ucom_modem;
163 static tsw_param_t ucom_param;
164 static tsw_outwakeup_t ucom_outwakeup;
165 static tsw_free_t ucom_free;
166 
167 static struct ttydevsw ucom_class = {
168 	.tsw_flags = TF_INITLOCK | TF_CALLOUT,
169 	.tsw_open = ucom_open,
170 	.tsw_close = ucom_close,
171 	.tsw_outwakeup = ucom_outwakeup,
172 	.tsw_ioctl = ucom_ioctl,
173 	.tsw_param = ucom_param,
174 	.tsw_modem = ucom_modem,
175 	.tsw_free = ucom_free,
176 };
177 
178 MODULE_DEPEND(ucom, usb, 1, 1, 1);
179 MODULE_VERSION(ucom, 1);
180 
181 #define	UCOM_UNIT_MAX 		128	/* limits size of ucom_bitmap */
182 
183 static uint8_t ucom_bitmap[(UCOM_UNIT_MAX + 7) / 8];
184 static struct mtx ucom_bitmap_mtx;
185 MTX_SYSINIT(ucom_bitmap_mtx, &ucom_bitmap_mtx, "ucom bitmap", MTX_DEF);
186 
187 #define UCOM_TTY_PREFIX		"U"
188 
189 /*
190  * Mark a unit number (the X in cuaUX) as in use.
191  *
192  * Note that devices using a different naming scheme (see ucom_tty_name()
193  * callback) still use this unit allocation.
194  */
195 static int
196 ucom_unit_alloc(void)
197 {
198 	int unit;
199 
200 	mtx_lock(&ucom_bitmap_mtx);
201 
202 	for (unit = 0; unit < UCOM_UNIT_MAX; unit++) {
203 		if ((ucom_bitmap[unit / 8] & (1 << (unit % 8))) == 0) {
204 			ucom_bitmap[unit / 8] |= (1 << (unit % 8));
205 			break;
206 		}
207 	}
208 
209 	mtx_unlock(&ucom_bitmap_mtx);
210 
211 	if (unit == UCOM_UNIT_MAX)
212 		return -1;
213 	else
214 		return unit;
215 }
216 
217 /*
218  * Mark the unit number as not in use.
219  */
220 static void
221 ucom_unit_free(int unit)
222 {
223 	mtx_lock(&ucom_bitmap_mtx);
224 
225 	ucom_bitmap[unit / 8] &= ~(1 << (unit % 8));
226 
227 	mtx_unlock(&ucom_bitmap_mtx);
228 }
229 
230 /*
231  * Setup a group of one or more serial ports.
232  *
233  * The mutex pointed to by "mtx" is applied before all
234  * callbacks are called back. Also "mtx" must be applied
235  * before calling into the ucom-layer!
236  */
237 int
238 ucom_attach(struct ucom_super_softc *ssc, struct ucom_softc *sc,
239     uint32_t subunits, void *parent,
240     const struct ucom_callback *callback, struct mtx *mtx)
241 {
242 	uint32_t subunit;
243 	int error = 0;
244 
245 	if ((sc == NULL) ||
246 	    (subunits == 0) ||
247 	    (callback == NULL)) {
248 		return (EINVAL);
249 	}
250 
251 	ssc->sc_unit = ucom_unit_alloc();
252 	if (ssc->sc_unit == -1)
253 		return (ENOMEM);
254 
255 	error = usb_proc_create(&ssc->sc_tq, mtx, "ucom", USB_PRI_MED);
256 	if (error) {
257 		ucom_unit_free(ssc->sc_unit);
258 		return (error);
259 	}
260 	ssc->sc_subunits = subunits;
261 
262 	for (subunit = 0; subunit < ssc->sc_subunits; subunit++) {
263 		sc[subunit].sc_subunit = subunit;
264 		sc[subunit].sc_super = ssc;
265 		sc[subunit].sc_mtx = mtx;
266 		sc[subunit].sc_parent = parent;
267 		sc[subunit].sc_callback = callback;
268 
269 		error = ucom_attach_tty(ssc, &sc[subunit]);
270 		if (error) {
271 			ucom_detach(ssc, &sc[0]);
272 			return (error);
273 		}
274 		sc[subunit].sc_flag |= UCOM_FLAG_ATTACHED;
275 	}
276 
277 	DPRINTF("tp = %p, unit = %d, subunits = %d\n",
278 		sc->sc_tty, ssc->sc_unit, ssc->sc_subunits);
279 
280 	return (0);
281 }
282 
283 /*
284  * NOTE: the following function will do nothing if
285  * the structure pointed to by "ssc" and "sc" is zero.
286  */
287 void
288 ucom_detach(struct ucom_super_softc *ssc, struct ucom_softc *sc)
289 {
290 	uint32_t subunit;
291 
292 	if (ssc->sc_subunits == 0)
293 		return;		/* not initialized */
294 
295 	usb_proc_drain(&ssc->sc_tq);
296 
297 	for (subunit = 0; subunit < ssc->sc_subunits; subunit++) {
298 		if (sc[subunit].sc_flag & UCOM_FLAG_ATTACHED) {
299 
300 			ucom_detach_tty(&sc[subunit]);
301 
302 			/* avoid duplicate detach */
303 			sc[subunit].sc_flag &= ~UCOM_FLAG_ATTACHED;
304 		}
305 	}
306 	ucom_unit_free(ssc->sc_unit);
307 	usb_proc_free(&ssc->sc_tq);
308 }
309 
310 static int
311 ucom_attach_tty(struct ucom_super_softc *ssc, struct ucom_softc *sc)
312 {
313 	struct tty *tp;
314 	char buf[32];			/* temporary TTY device name buffer */
315 
316 	tp = tty_alloc_mutex(&ucom_class, sc, sc->sc_mtx);
317 	if (tp == NULL)
318 		return (ENOMEM);
319 
320 	/* Check if the client has a custom TTY name */
321 	buf[0] = '\0';
322 	if (sc->sc_callback->ucom_tty_name) {
323 		sc->sc_callback->ucom_tty_name(sc, buf,
324 		    sizeof(buf), ssc->sc_unit, sc->sc_subunit);
325 	}
326 	if (buf[0] == 0) {
327 		/* Use default TTY name */
328 		if (ssc->sc_subunits > 1) {
329 			/* multiple modems in one */
330 			snprintf(buf, sizeof(buf), UCOM_TTY_PREFIX "%u.%u",
331 			    ssc->sc_unit, sc->sc_subunit);
332 		} else {
333 			/* single modem */
334 			snprintf(buf, sizeof(buf), UCOM_TTY_PREFIX "%u",
335 			    ssc->sc_unit);
336 		}
337 	}
338 	tty_makedev(tp, NULL, "%s", buf);
339 
340 	sc->sc_tty = tp;
341 
342 	DPRINTF("ttycreate: %s\n", buf);
343 	cv_init(&sc->sc_cv, "ucom");
344 
345 	/* Check if this device should be a console */
346 	if ((ucom_cons_softc == NULL) &&
347 	    (ssc->sc_unit == ucom_cons_unit) &&
348 	    (sc->sc_subunit == ucom_cons_subunit)) {
349 		struct termios t;
350 
351 		DPRINTF("unit %d subunit %d is console", ssc->sc_unit, sc->sc_subunit);
352 
353 		ucom_cons_softc = sc;
354 
355 		memset(&t, 0, sizeof(t));
356 		t.c_ispeed = ucom_cons_baud;
357 		t.c_ospeed = t.c_ispeed;
358 		t.c_cflag = CS8;
359 
360 		mtx_lock(ucom_cons_softc->sc_mtx);
361 		ucom_cons_rx_low = 0;
362 		ucom_cons_rx_high = 0;
363 		ucom_cons_tx_low = 0;
364 		ucom_cons_tx_high = 0;
365 		sc->sc_flag |= UCOM_FLAG_CONSOLE;
366 		ucom_open(ucom_cons_softc->sc_tty);
367 		ucom_param(ucom_cons_softc->sc_tty, &t);
368 		mtx_unlock(ucom_cons_softc->sc_mtx);
369 	}
370 
371 	return (0);
372 }
373 
374 static void
375 ucom_detach_tty(struct ucom_softc *sc)
376 {
377 	struct tty *tp = sc->sc_tty;
378 
379 	DPRINTF("sc = %p, tp = %p\n", sc, sc->sc_tty);
380 
381 	if (sc->sc_flag & UCOM_FLAG_CONSOLE) {
382 		mtx_lock(ucom_cons_softc->sc_mtx);
383 		ucom_close(ucom_cons_softc->sc_tty);
384 		sc->sc_flag &= ~UCOM_FLAG_CONSOLE;
385 		mtx_unlock(ucom_cons_softc->sc_mtx);
386 		ucom_cons_softc = NULL;
387 	}
388 
389 	/* the config thread has been stopped when we get here */
390 
391 	mtx_lock(sc->sc_mtx);
392 	sc->sc_flag |= UCOM_FLAG_GONE;
393 	sc->sc_flag &= ~(UCOM_FLAG_HL_READY | UCOM_FLAG_LL_READY);
394 	mtx_unlock(sc->sc_mtx);
395 	if (tp) {
396 		tty_lock(tp);
397 
398 		ucom_close(tp);	/* close, if any */
399 
400 		tty_rel_gone(tp);
401 
402 		mtx_lock(sc->sc_mtx);
403 		/* Wait for the callback after the TTY is torn down */
404 		while (sc->sc_ttyfreed == 0)
405 			cv_wait(&sc->sc_cv, sc->sc_mtx);
406 		/*
407 		 * make sure that read and write transfers are stopped
408 		 */
409 		if (sc->sc_callback->ucom_stop_read) {
410 			(sc->sc_callback->ucom_stop_read) (sc);
411 		}
412 		if (sc->sc_callback->ucom_stop_write) {
413 			(sc->sc_callback->ucom_stop_write) (sc);
414 		}
415 		mtx_unlock(sc->sc_mtx);
416 	}
417 	cv_destroy(&sc->sc_cv);
418 }
419 
420 void
421 ucom_set_pnpinfo_usb(struct ucom_super_softc *ssc, device_t dev)
422 {
423     char buf[64];
424     uint8_t iface_index;
425     struct usb_attach_arg *uaa;
426 
427     snprintf(buf, sizeof(buf), "ttyname=%s%d ttyports=%d",
428 	     UCOM_TTY_PREFIX, ssc->sc_unit, ssc->sc_subunits);
429 
430     /* Store the PNP info in the first interface for the dev */
431     uaa = device_get_ivars(dev);
432     iface_index = uaa->info.bIfaceIndex;
433 
434     if (usbd_set_pnpinfo(uaa->device, iface_index, buf) != 0)
435 	device_printf(dev, "Could not set PNP info\n");
436 }
437 
438 static void
439 ucom_queue_command(struct ucom_softc *sc,
440     usb_proc_callback_t *fn, struct termios *pt,
441     struct usb_proc_msg *t0, struct usb_proc_msg *t1)
442 {
443 	struct ucom_super_softc *ssc = sc->sc_super;
444 	struct ucom_param_task *task;
445 
446 	mtx_assert(sc->sc_mtx, MA_OWNED);
447 
448 	if (usb_proc_is_gone(&ssc->sc_tq)) {
449 		DPRINTF("proc is gone\n");
450 		return;         /* nothing to do */
451 	}
452 	/*
453 	 * NOTE: The task cannot get executed before we drop the
454 	 * "sc_mtx" mutex. It is safe to update fields in the message
455 	 * structure after that the message got queued.
456 	 */
457 	task = (struct ucom_param_task *)
458 	  usb_proc_msignal(&ssc->sc_tq, t0, t1);
459 
460 	/* Setup callback and softc pointers */
461 	task->hdr.pm_callback = fn;
462 	task->sc = sc;
463 
464 	/*
465 	 * Make a copy of the termios. This field is only present if
466 	 * the "pt" field is not NULL.
467 	 */
468 	if (pt != NULL)
469 		task->termios_copy = *pt;
470 
471 	/*
472 	 * Closing the device should be synchronous.
473 	 */
474 	if (fn == ucom_cfg_close)
475 		usb_proc_mwait(&ssc->sc_tq, t0, t1);
476 
477 	/*
478 	 * In case of multiple configure requests,
479 	 * keep track of the last one!
480 	 */
481 	if (fn == ucom_cfg_start_transfers)
482 		sc->sc_last_start_xfer = &task->hdr;
483 }
484 
485 static void
486 ucom_shutdown(struct ucom_softc *sc)
487 {
488 	struct tty *tp = sc->sc_tty;
489 
490 	mtx_assert(sc->sc_mtx, MA_OWNED);
491 
492 	DPRINTF("\n");
493 
494 	/*
495 	 * Hang up if necessary:
496 	 */
497 	if (tp->t_termios.c_cflag & HUPCL) {
498 		ucom_modem(tp, 0, SER_DTR);
499 	}
500 }
501 
502 /*
503  * Return values:
504  *    0: normal
505  * else: taskqueue is draining or gone
506  */
507 uint8_t
508 ucom_cfg_is_gone(struct ucom_softc *sc)
509 {
510 	struct ucom_super_softc *ssc = sc->sc_super;
511 
512 	return (usb_proc_is_gone(&ssc->sc_tq));
513 }
514 
515 static void
516 ucom_cfg_start_transfers(struct usb_proc_msg *_task)
517 {
518 	struct ucom_cfg_task *task =
519 	    (struct ucom_cfg_task *)_task;
520 	struct ucom_softc *sc = task->sc;
521 
522 	if (!(sc->sc_flag & UCOM_FLAG_LL_READY)) {
523 		return;
524 	}
525 	if (!(sc->sc_flag & UCOM_FLAG_HL_READY)) {
526 		/* TTY device closed */
527 		return;
528 	}
529 
530 	if (_task == sc->sc_last_start_xfer)
531 		sc->sc_flag |= UCOM_FLAG_GP_DATA;
532 
533 	if (sc->sc_callback->ucom_start_read) {
534 		(sc->sc_callback->ucom_start_read) (sc);
535 	}
536 	if (sc->sc_callback->ucom_start_write) {
537 		(sc->sc_callback->ucom_start_write) (sc);
538 	}
539 }
540 
541 static void
542 ucom_start_transfers(struct ucom_softc *sc)
543 {
544 	if (!(sc->sc_flag & UCOM_FLAG_HL_READY)) {
545 		return;
546 	}
547 	/*
548 	 * Make sure that data transfers are started in both
549 	 * directions:
550 	 */
551 	if (sc->sc_callback->ucom_start_read) {
552 		(sc->sc_callback->ucom_start_read) (sc);
553 	}
554 	if (sc->sc_callback->ucom_start_write) {
555 		(sc->sc_callback->ucom_start_write) (sc);
556 	}
557 }
558 
559 static void
560 ucom_cfg_open(struct usb_proc_msg *_task)
561 {
562 	struct ucom_cfg_task *task =
563 	    (struct ucom_cfg_task *)_task;
564 	struct ucom_softc *sc = task->sc;
565 
566 	DPRINTF("\n");
567 
568 	if (sc->sc_flag & UCOM_FLAG_LL_READY) {
569 
570 		/* already opened */
571 
572 	} else {
573 
574 		sc->sc_flag |= UCOM_FLAG_LL_READY;
575 
576 		if (sc->sc_callback->ucom_cfg_open) {
577 			(sc->sc_callback->ucom_cfg_open) (sc);
578 
579 			/* wait a little */
580 			usb_pause_mtx(sc->sc_mtx, hz / 10);
581 		}
582 	}
583 }
584 
585 static int
586 ucom_open(struct tty *tp)
587 {
588 	struct ucom_softc *sc = tty_softc(tp);
589 	int error;
590 
591 	mtx_assert(sc->sc_mtx, MA_OWNED);
592 
593 	if (sc->sc_flag & UCOM_FLAG_GONE) {
594 		return (ENXIO);
595 	}
596 	if (sc->sc_flag & UCOM_FLAG_HL_READY) {
597 		/* already opened */
598 		return (0);
599 	}
600 	DPRINTF("tp = %p\n", tp);
601 
602 	if (sc->sc_callback->ucom_pre_open) {
603 		/*
604 		 * give the lower layer a chance to disallow TTY open, for
605 		 * example if the device is not present:
606 		 */
607 		error = (sc->sc_callback->ucom_pre_open) (sc);
608 		if (error) {
609 			return (error);
610 		}
611 	}
612 	sc->sc_flag |= UCOM_FLAG_HL_READY;
613 
614 	/* Disable transfers */
615 	sc->sc_flag &= ~UCOM_FLAG_GP_DATA;
616 
617 	sc->sc_lsr = 0;
618 	sc->sc_msr = 0;
619 	sc->sc_mcr = 0;
620 
621 	/* reset programmed line state */
622 	sc->sc_pls_curr = 0;
623 	sc->sc_pls_set = 0;
624 	sc->sc_pls_clr = 0;
625 
626 	ucom_queue_command(sc, ucom_cfg_open, NULL,
627 	    &sc->sc_open_task[0].hdr,
628 	    &sc->sc_open_task[1].hdr);
629 
630 	/* Queue transfer enable command last */
631 	ucom_queue_command(sc, ucom_cfg_start_transfers, NULL,
632 	    &sc->sc_start_task[0].hdr,
633 	    &sc->sc_start_task[1].hdr);
634 
635 	ucom_modem(tp, SER_DTR | SER_RTS, 0);
636 
637 	ucom_ring(sc, 0);
638 
639 	ucom_break(sc, 0);
640 
641 	ucom_status_change(sc);
642 
643 	return (0);
644 }
645 
646 static void
647 ucom_cfg_close(struct usb_proc_msg *_task)
648 {
649 	struct ucom_cfg_task *task =
650 	    (struct ucom_cfg_task *)_task;
651 	struct ucom_softc *sc = task->sc;
652 
653 	DPRINTF("\n");
654 
655 	if (sc->sc_flag & UCOM_FLAG_LL_READY) {
656 		sc->sc_flag &= ~UCOM_FLAG_LL_READY;
657 		if (sc->sc_callback->ucom_cfg_close)
658 			(sc->sc_callback->ucom_cfg_close) (sc);
659 	} else {
660 		/* already closed */
661 	}
662 }
663 
664 static void
665 ucom_close(struct tty *tp)
666 {
667 	struct ucom_softc *sc = tty_softc(tp);
668 
669 	mtx_assert(sc->sc_mtx, MA_OWNED);
670 
671 	DPRINTF("tp=%p\n", tp);
672 
673 	if (!(sc->sc_flag & UCOM_FLAG_HL_READY)) {
674 		DPRINTF("tp=%p already closed\n", tp);
675 		return;
676 	}
677 	ucom_shutdown(sc);
678 
679 	ucom_queue_command(sc, ucom_cfg_close, NULL,
680 	    &sc->sc_close_task[0].hdr,
681 	    &sc->sc_close_task[1].hdr);
682 
683 	sc->sc_flag &= ~(UCOM_FLAG_HL_READY | UCOM_FLAG_RTS_IFLOW);
684 
685 	if (sc->sc_callback->ucom_stop_read) {
686 		(sc->sc_callback->ucom_stop_read) (sc);
687 	}
688 }
689 
690 static int
691 ucom_ioctl(struct tty *tp, u_long cmd, caddr_t data, struct thread *td)
692 {
693 	struct ucom_softc *sc = tty_softc(tp);
694 	int error;
695 
696 	mtx_assert(sc->sc_mtx, MA_OWNED);
697 
698 	if (!(sc->sc_flag & UCOM_FLAG_HL_READY)) {
699 		return (EIO);
700 	}
701 	DPRINTF("cmd = 0x%08lx\n", cmd);
702 
703 	switch (cmd) {
704 #if 0
705 	case TIOCSRING:
706 		ucom_ring(sc, 1);
707 		error = 0;
708 		break;
709 	case TIOCCRING:
710 		ucom_ring(sc, 0);
711 		error = 0;
712 		break;
713 #endif
714 	case TIOCSBRK:
715 		ucom_break(sc, 1);
716 		error = 0;
717 		break;
718 	case TIOCCBRK:
719 		ucom_break(sc, 0);
720 		error = 0;
721 		break;
722 	default:
723 		if (sc->sc_callback->ucom_ioctl) {
724 			error = (sc->sc_callback->ucom_ioctl)
725 			    (sc, cmd, data, 0, td);
726 		} else {
727 			error = ENOIOCTL;
728 		}
729 		break;
730 	}
731 	return (error);
732 }
733 
734 static int
735 ucom_modem(struct tty *tp, int sigon, int sigoff)
736 {
737 	struct ucom_softc *sc = tty_softc(tp);
738 	uint8_t onoff;
739 
740 	mtx_assert(sc->sc_mtx, MA_OWNED);
741 
742 	if (!(sc->sc_flag & UCOM_FLAG_HL_READY)) {
743 		return (0);
744 	}
745 	if ((sigon == 0) && (sigoff == 0)) {
746 
747 		if (sc->sc_mcr & SER_DTR) {
748 			sigon |= SER_DTR;
749 		}
750 		if (sc->sc_mcr & SER_RTS) {
751 			sigon |= SER_RTS;
752 		}
753 		if (sc->sc_msr & SER_CTS) {
754 			sigon |= SER_CTS;
755 		}
756 		if (sc->sc_msr & SER_DCD) {
757 			sigon |= SER_DCD;
758 		}
759 		if (sc->sc_msr & SER_DSR) {
760 			sigon |= SER_DSR;
761 		}
762 		if (sc->sc_msr & SER_RI) {
763 			sigon |= SER_RI;
764 		}
765 		return (sigon);
766 	}
767 	if (sigon & SER_DTR) {
768 		sc->sc_mcr |= SER_DTR;
769 	}
770 	if (sigoff & SER_DTR) {
771 		sc->sc_mcr &= ~SER_DTR;
772 	}
773 	if (sigon & SER_RTS) {
774 		sc->sc_mcr |= SER_RTS;
775 	}
776 	if (sigoff & SER_RTS) {
777 		sc->sc_mcr &= ~SER_RTS;
778 	}
779 	onoff = (sc->sc_mcr & SER_DTR) ? 1 : 0;
780 	ucom_dtr(sc, onoff);
781 
782 	onoff = (sc->sc_mcr & SER_RTS) ? 1 : 0;
783 	ucom_rts(sc, onoff);
784 
785 	return (0);
786 }
787 
788 static void
789 ucom_cfg_line_state(struct usb_proc_msg *_task)
790 {
791 	struct ucom_cfg_task *task =
792 	    (struct ucom_cfg_task *)_task;
793 	struct ucom_softc *sc = task->sc;
794 	uint8_t notch_bits;
795 	uint8_t any_bits;
796 	uint8_t prev_value;
797 	uint8_t last_value;
798 	uint8_t mask;
799 
800 	if (!(sc->sc_flag & UCOM_FLAG_LL_READY)) {
801 		return;
802 	}
803 
804 	mask = 0;
805 	/* compute callback mask */
806 	if (sc->sc_callback->ucom_cfg_set_dtr)
807 		mask |= UCOM_LS_DTR;
808 	if (sc->sc_callback->ucom_cfg_set_rts)
809 		mask |= UCOM_LS_RTS;
810 	if (sc->sc_callback->ucom_cfg_set_break)
811 		mask |= UCOM_LS_BREAK;
812 	if (sc->sc_callback->ucom_cfg_set_ring)
813 		mask |= UCOM_LS_RING;
814 
815 	/* compute the bits we are to program */
816 	notch_bits = (sc->sc_pls_set & sc->sc_pls_clr) & mask;
817 	any_bits = (sc->sc_pls_set | sc->sc_pls_clr) & mask;
818 	prev_value = sc->sc_pls_curr ^ notch_bits;
819 	last_value = sc->sc_pls_curr;
820 
821 	/* reset programmed line state */
822 	sc->sc_pls_curr = 0;
823 	sc->sc_pls_set = 0;
824 	sc->sc_pls_clr = 0;
825 
826 	/* ensure that we don't loose any levels */
827 	if (notch_bits & UCOM_LS_DTR)
828 		sc->sc_callback->ucom_cfg_set_dtr(sc,
829 		    (prev_value & UCOM_LS_DTR) ? 1 : 0);
830 	if (notch_bits & UCOM_LS_RTS)
831 		sc->sc_callback->ucom_cfg_set_rts(sc,
832 		    (prev_value & UCOM_LS_RTS) ? 1 : 0);
833 	if (notch_bits & UCOM_LS_BREAK)
834 		sc->sc_callback->ucom_cfg_set_break(sc,
835 		    (prev_value & UCOM_LS_BREAK) ? 1 : 0);
836 	if (notch_bits & UCOM_LS_RING)
837 		sc->sc_callback->ucom_cfg_set_ring(sc,
838 		    (prev_value & UCOM_LS_RING) ? 1 : 0);
839 
840 	/* set last value */
841 	if (any_bits & UCOM_LS_DTR)
842 		sc->sc_callback->ucom_cfg_set_dtr(sc,
843 		    (last_value & UCOM_LS_DTR) ? 1 : 0);
844 	if (any_bits & UCOM_LS_RTS)
845 		sc->sc_callback->ucom_cfg_set_rts(sc,
846 		    (last_value & UCOM_LS_RTS) ? 1 : 0);
847 	if (any_bits & UCOM_LS_BREAK)
848 		sc->sc_callback->ucom_cfg_set_break(sc,
849 		    (last_value & UCOM_LS_BREAK) ? 1 : 0);
850 	if (any_bits & UCOM_LS_RING)
851 		sc->sc_callback->ucom_cfg_set_ring(sc,
852 		    (last_value & UCOM_LS_RING) ? 1 : 0);
853 }
854 
855 static void
856 ucom_line_state(struct ucom_softc *sc,
857     uint8_t set_bits, uint8_t clear_bits)
858 {
859 	mtx_assert(sc->sc_mtx, MA_OWNED);
860 
861 	if (!(sc->sc_flag & UCOM_FLAG_HL_READY)) {
862 		return;
863 	}
864 
865 	DPRINTF("on=0x%02x, off=0x%02x\n", set_bits, clear_bits);
866 
867 	/* update current programmed line state */
868 	sc->sc_pls_curr |= set_bits;
869 	sc->sc_pls_curr &= ~clear_bits;
870 	sc->sc_pls_set |= set_bits;
871 	sc->sc_pls_clr |= clear_bits;
872 
873 	/* defer driver programming */
874 	ucom_queue_command(sc, ucom_cfg_line_state, NULL,
875 	    &sc->sc_line_state_task[0].hdr,
876 	    &sc->sc_line_state_task[1].hdr);
877 }
878 
879 static void
880 ucom_ring(struct ucom_softc *sc, uint8_t onoff)
881 {
882 	DPRINTF("onoff = %d\n", onoff);
883 
884 	if (onoff)
885 		ucom_line_state(sc, UCOM_LS_RING, 0);
886 	else
887 		ucom_line_state(sc, 0, UCOM_LS_RING);
888 }
889 
890 static void
891 ucom_break(struct ucom_softc *sc, uint8_t onoff)
892 {
893 	DPRINTF("onoff = %d\n", onoff);
894 
895 	if (onoff)
896 		ucom_line_state(sc, UCOM_LS_BREAK, 0);
897 	else
898 		ucom_line_state(sc, 0, UCOM_LS_BREAK);
899 }
900 
901 static void
902 ucom_dtr(struct ucom_softc *sc, uint8_t onoff)
903 {
904 	DPRINTF("onoff = %d\n", onoff);
905 
906 	if (onoff)
907 		ucom_line_state(sc, UCOM_LS_DTR, 0);
908 	else
909 		ucom_line_state(sc, 0, UCOM_LS_DTR);
910 }
911 
912 static void
913 ucom_rts(struct ucom_softc *sc, uint8_t onoff)
914 {
915 	DPRINTF("onoff = %d\n", onoff);
916 
917 	if (onoff)
918 		ucom_line_state(sc, UCOM_LS_RTS, 0);
919 	else
920 		ucom_line_state(sc, 0, UCOM_LS_RTS);
921 }
922 
923 static void
924 ucom_cfg_status_change(struct usb_proc_msg *_task)
925 {
926 	struct ucom_cfg_task *task =
927 	    (struct ucom_cfg_task *)_task;
928 	struct ucom_softc *sc = task->sc;
929 	struct tty *tp;
930 	uint8_t new_msr;
931 	uint8_t new_lsr;
932 	uint8_t onoff;
933 	uint8_t lsr_delta;
934 
935 	tp = sc->sc_tty;
936 
937 	mtx_assert(sc->sc_mtx, MA_OWNED);
938 
939 	if (!(sc->sc_flag & UCOM_FLAG_LL_READY)) {
940 		return;
941 	}
942 	if (sc->sc_callback->ucom_cfg_get_status == NULL) {
943 		return;
944 	}
945 	/* get status */
946 
947 	new_msr = 0;
948 	new_lsr = 0;
949 
950 	(sc->sc_callback->ucom_cfg_get_status) (sc, &new_lsr, &new_msr);
951 
952 	if (!(sc->sc_flag & UCOM_FLAG_HL_READY)) {
953 		/* TTY device closed */
954 		return;
955 	}
956 	onoff = ((sc->sc_msr ^ new_msr) & SER_DCD);
957 	lsr_delta = (sc->sc_lsr ^ new_lsr);
958 
959 	sc->sc_msr = new_msr;
960 	sc->sc_lsr = new_lsr;
961 
962 	if (onoff) {
963 
964 		onoff = (sc->sc_msr & SER_DCD) ? 1 : 0;
965 
966 		DPRINTF("DCD changed to %d\n", onoff);
967 
968 		ttydisc_modem(tp, onoff);
969 	}
970 
971 	if ((lsr_delta & ULSR_BI) && (sc->sc_lsr & ULSR_BI)) {
972 
973 		DPRINTF("BREAK detected\n");
974 
975 		ttydisc_rint(tp, 0, TRE_BREAK);
976 		ttydisc_rint_done(tp);
977 	}
978 
979 	if ((lsr_delta & ULSR_FE) && (sc->sc_lsr & ULSR_FE)) {
980 
981 		DPRINTF("Frame error detected\n");
982 
983 		ttydisc_rint(tp, 0, TRE_FRAMING);
984 		ttydisc_rint_done(tp);
985 	}
986 
987 	if ((lsr_delta & ULSR_PE) && (sc->sc_lsr & ULSR_PE)) {
988 
989 		DPRINTF("Parity error detected\n");
990 
991 		ttydisc_rint(tp, 0, TRE_PARITY);
992 		ttydisc_rint_done(tp);
993 	}
994 }
995 
996 void
997 ucom_status_change(struct ucom_softc *sc)
998 {
999 	mtx_assert(sc->sc_mtx, MA_OWNED);
1000 
1001 	if (sc->sc_flag & UCOM_FLAG_CONSOLE)
1002 		return;		/* not supported */
1003 
1004 	if (!(sc->sc_flag & UCOM_FLAG_HL_READY)) {
1005 		return;
1006 	}
1007 	DPRINTF("\n");
1008 
1009 	ucom_queue_command(sc, ucom_cfg_status_change, NULL,
1010 	    &sc->sc_status_task[0].hdr,
1011 	    &sc->sc_status_task[1].hdr);
1012 }
1013 
1014 static void
1015 ucom_cfg_param(struct usb_proc_msg *_task)
1016 {
1017 	struct ucom_param_task *task =
1018 	    (struct ucom_param_task *)_task;
1019 	struct ucom_softc *sc = task->sc;
1020 
1021 	if (!(sc->sc_flag & UCOM_FLAG_LL_READY)) {
1022 		return;
1023 	}
1024 	if (sc->sc_callback->ucom_cfg_param == NULL) {
1025 		return;
1026 	}
1027 
1028 	(sc->sc_callback->ucom_cfg_param) (sc, &task->termios_copy);
1029 
1030 	/* wait a little */
1031 	usb_pause_mtx(sc->sc_mtx, hz / 10);
1032 }
1033 
1034 static int
1035 ucom_param(struct tty *tp, struct termios *t)
1036 {
1037 	struct ucom_softc *sc = tty_softc(tp);
1038 	uint8_t opened;
1039 	int error;
1040 
1041 	mtx_assert(sc->sc_mtx, MA_OWNED);
1042 
1043 	opened = 0;
1044 	error = 0;
1045 
1046 	if (!(sc->sc_flag & UCOM_FLAG_HL_READY)) {
1047 
1048 		/* XXX the TTY layer should call "open()" first! */
1049 
1050 		error = ucom_open(tp);
1051 		if (error) {
1052 			goto done;
1053 		}
1054 		opened = 1;
1055 	}
1056 	DPRINTF("sc = %p\n", sc);
1057 
1058 	/* Check requested parameters. */
1059 	if (t->c_ospeed < 0) {
1060 		DPRINTF("negative ospeed\n");
1061 		error = EINVAL;
1062 		goto done;
1063 	}
1064 	if (t->c_ispeed && (t->c_ispeed != t->c_ospeed)) {
1065 		DPRINTF("mismatch ispeed and ospeed\n");
1066 		error = EINVAL;
1067 		goto done;
1068 	}
1069 	t->c_ispeed = t->c_ospeed;
1070 
1071 	if (sc->sc_callback->ucom_pre_param) {
1072 		/* Let the lower layer verify the parameters */
1073 		error = (sc->sc_callback->ucom_pre_param) (sc, t);
1074 		if (error) {
1075 			DPRINTF("callback error = %d\n", error);
1076 			goto done;
1077 		}
1078 	}
1079 
1080 	/* Disable transfers */
1081 	sc->sc_flag &= ~UCOM_FLAG_GP_DATA;
1082 
1083 	/* Queue baud rate programming command first */
1084 	ucom_queue_command(sc, ucom_cfg_param, t,
1085 	    &sc->sc_param_task[0].hdr,
1086 	    &sc->sc_param_task[1].hdr);
1087 
1088 	/* Queue transfer enable command last */
1089 	ucom_queue_command(sc, ucom_cfg_start_transfers, NULL,
1090 	    &sc->sc_start_task[0].hdr,
1091 	    &sc->sc_start_task[1].hdr);
1092 
1093 	if (t->c_cflag & CRTS_IFLOW) {
1094 		sc->sc_flag |= UCOM_FLAG_RTS_IFLOW;
1095 	} else if (sc->sc_flag & UCOM_FLAG_RTS_IFLOW) {
1096 		sc->sc_flag &= ~UCOM_FLAG_RTS_IFLOW;
1097 		ucom_modem(tp, SER_RTS, 0);
1098 	}
1099 done:
1100 	if (error) {
1101 		if (opened) {
1102 			ucom_close(tp);
1103 		}
1104 	}
1105 	return (error);
1106 }
1107 
1108 static void
1109 ucom_outwakeup(struct tty *tp)
1110 {
1111 	struct ucom_softc *sc = tty_softc(tp);
1112 
1113 	mtx_assert(sc->sc_mtx, MA_OWNED);
1114 
1115 	DPRINTF("sc = %p\n", sc);
1116 
1117 	if (!(sc->sc_flag & UCOM_FLAG_HL_READY)) {
1118 		/* The higher layer is not ready */
1119 		return;
1120 	}
1121 	ucom_start_transfers(sc);
1122 }
1123 
1124 /*------------------------------------------------------------------------*
1125  *	ucom_get_data
1126  *
1127  * Return values:
1128  * 0: No data is available.
1129  * Else: Data is available.
1130  *------------------------------------------------------------------------*/
1131 uint8_t
1132 ucom_get_data(struct ucom_softc *sc, struct usb_page_cache *pc,
1133     uint32_t offset, uint32_t len, uint32_t *actlen)
1134 {
1135 	struct usb_page_search res;
1136 	struct tty *tp = sc->sc_tty;
1137 	uint32_t cnt;
1138 	uint32_t offset_orig;
1139 
1140 	mtx_assert(sc->sc_mtx, MA_OWNED);
1141 
1142 	if (sc->sc_flag & UCOM_FLAG_CONSOLE) {
1143 		unsigned int temp;
1144 
1145 		/* get total TX length */
1146 
1147 		temp = ucom_cons_tx_high - ucom_cons_tx_low;
1148 		temp %= UCOM_CONS_BUFSIZE;
1149 
1150 		/* limit TX length */
1151 
1152 		if (temp > (UCOM_CONS_BUFSIZE - ucom_cons_tx_low))
1153 			temp = (UCOM_CONS_BUFSIZE - ucom_cons_tx_low);
1154 
1155 		if (temp > len)
1156 			temp = len;
1157 
1158 		/* copy in data */
1159 
1160 		usbd_copy_in(pc, offset, ucom_cons_tx_buf + ucom_cons_tx_low, temp);
1161 
1162 		/* update counters */
1163 
1164 		ucom_cons_tx_low += temp;
1165 		ucom_cons_tx_low %= UCOM_CONS_BUFSIZE;
1166 
1167 		/* store actual length */
1168 
1169 		*actlen = temp;
1170 
1171 		return (temp ? 1 : 0);
1172 	}
1173 
1174 	if (tty_gone(tp) ||
1175 	    !(sc->sc_flag & UCOM_FLAG_GP_DATA)) {
1176 		actlen[0] = 0;
1177 		return (0);		/* multiport device polling */
1178 	}
1179 	offset_orig = offset;
1180 
1181 	while (len != 0) {
1182 
1183 		usbd_get_page(pc, offset, &res);
1184 
1185 		if (res.length > len) {
1186 			res.length = len;
1187 		}
1188 		/* copy data directly into USB buffer */
1189 		cnt = ttydisc_getc(tp, res.buffer, res.length);
1190 
1191 		offset += cnt;
1192 		len -= cnt;
1193 
1194 		if (cnt < res.length) {
1195 			/* end of buffer */
1196 			break;
1197 		}
1198 	}
1199 
1200 	actlen[0] = offset - offset_orig;
1201 
1202 	DPRINTF("cnt=%d\n", actlen[0]);
1203 
1204 	if (actlen[0] == 0) {
1205 		return (0);
1206 	}
1207 	return (1);
1208 }
1209 
1210 void
1211 ucom_put_data(struct ucom_softc *sc, struct usb_page_cache *pc,
1212     uint32_t offset, uint32_t len)
1213 {
1214 	struct usb_page_search res;
1215 	struct tty *tp = sc->sc_tty;
1216 	char *buf;
1217 	uint32_t cnt;
1218 
1219 	mtx_assert(sc->sc_mtx, MA_OWNED);
1220 
1221 	if (sc->sc_flag & UCOM_FLAG_CONSOLE) {
1222 		unsigned int temp;
1223 
1224 		/* get maximum RX length */
1225 
1226 		temp = (UCOM_CONS_BUFSIZE - 1) - ucom_cons_rx_high + ucom_cons_rx_low;
1227 		temp %= UCOM_CONS_BUFSIZE;
1228 
1229 		/* limit RX length */
1230 
1231 		if (temp > (UCOM_CONS_BUFSIZE - ucom_cons_rx_high))
1232 			temp = (UCOM_CONS_BUFSIZE - ucom_cons_rx_high);
1233 
1234 		if (temp > len)
1235 			temp = len;
1236 
1237 		/* copy out data */
1238 
1239 		usbd_copy_out(pc, offset, ucom_cons_rx_buf + ucom_cons_rx_high, temp);
1240 
1241 		/* update counters */
1242 
1243 		ucom_cons_rx_high += temp;
1244 		ucom_cons_rx_high %= UCOM_CONS_BUFSIZE;
1245 
1246 		return;
1247 	}
1248 
1249 	if (tty_gone(tp))
1250 		return;			/* multiport device polling */
1251 
1252 	if (len == 0)
1253 		return;			/* no data */
1254 
1255 	/* set a flag to prevent recursation ? */
1256 
1257 	while (len > 0) {
1258 
1259 		usbd_get_page(pc, offset, &res);
1260 
1261 		if (res.length > len) {
1262 			res.length = len;
1263 		}
1264 		len -= res.length;
1265 		offset += res.length;
1266 
1267 		/* pass characters to tty layer */
1268 
1269 		buf = res.buffer;
1270 		cnt = res.length;
1271 
1272 		/* first check if we can pass the buffer directly */
1273 
1274 		if (ttydisc_can_bypass(tp)) {
1275 			if (ttydisc_rint_bypass(tp, buf, cnt) != cnt) {
1276 				DPRINTF("tp=%p, data lost\n", tp);
1277 			}
1278 			continue;
1279 		}
1280 		/* need to loop */
1281 
1282 		for (cnt = 0; cnt != res.length; cnt++) {
1283 			if (ttydisc_rint(tp, buf[cnt], 0) == -1) {
1284 				/* XXX what should we do? */
1285 
1286 				DPRINTF("tp=%p, lost %d "
1287 				    "chars\n", tp, res.length - cnt);
1288 				break;
1289 			}
1290 		}
1291 	}
1292 	ttydisc_rint_done(tp);
1293 }
1294 
1295 static void
1296 ucom_free(void *xsc)
1297 {
1298 	struct ucom_softc *sc = xsc;
1299 
1300 	mtx_lock(sc->sc_mtx);
1301 	sc->sc_ttyfreed = 1;
1302 	cv_signal(&sc->sc_cv);
1303 	mtx_unlock(sc->sc_mtx);
1304 }
1305 
1306 static cn_probe_t ucom_cnprobe;
1307 static cn_init_t ucom_cninit;
1308 static cn_term_t ucom_cnterm;
1309 static cn_getc_t ucom_cngetc;
1310 static cn_putc_t ucom_cnputc;
1311 static cn_grab_t ucom_cngrab;
1312 static cn_ungrab_t ucom_cnungrab;
1313 
1314 CONSOLE_DRIVER(ucom);
1315 
1316 static void
1317 ucom_cnprobe(struct consdev  *cp)
1318 {
1319 	if (ucom_cons_unit != -1)
1320 		cp->cn_pri = CN_NORMAL;
1321 	else
1322 		cp->cn_pri = CN_DEAD;
1323 
1324 	strlcpy(cp->cn_name, "ucom", sizeof(cp->cn_name));
1325 }
1326 
1327 static void
1328 ucom_cninit(struct consdev  *cp)
1329 {
1330 }
1331 
1332 static void
1333 ucom_cnterm(struct consdev  *cp)
1334 {
1335 }
1336 
1337 static void
1338 ucom_cngrab(struct consdev *cp)
1339 {
1340 }
1341 
1342 static void
1343 ucom_cnungrab(struct consdev *cp)
1344 {
1345 }
1346 
1347 static int
1348 ucom_cngetc(struct consdev *cd)
1349 {
1350 	struct ucom_softc *sc = ucom_cons_softc;
1351 	int c;
1352 
1353 	if (sc == NULL)
1354 		return (-1);
1355 
1356 	mtx_lock(sc->sc_mtx);
1357 
1358 	if (ucom_cons_rx_low != ucom_cons_rx_high) {
1359 		c = ucom_cons_rx_buf[ucom_cons_rx_low];
1360 		ucom_cons_rx_low ++;
1361 		ucom_cons_rx_low %= UCOM_CONS_BUFSIZE;
1362 	} else {
1363 		c = -1;
1364 	}
1365 
1366 	/* start USB transfers */
1367 	ucom_outwakeup(sc->sc_tty);
1368 
1369 	mtx_unlock(sc->sc_mtx);
1370 
1371 	/* poll if necessary */
1372 	if (kdb_active && sc->sc_callback->ucom_poll)
1373 		(sc->sc_callback->ucom_poll) (sc);
1374 
1375 	return (c);
1376 }
1377 
1378 static void
1379 ucom_cnputc(struct consdev *cd, int c)
1380 {
1381 	struct ucom_softc *sc = ucom_cons_softc;
1382 	unsigned int temp;
1383 
1384 	if (sc == NULL)
1385 		return;
1386 
1387  repeat:
1388 
1389 	mtx_lock(sc->sc_mtx);
1390 
1391 	/* compute maximum TX length */
1392 
1393 	temp = (UCOM_CONS_BUFSIZE - 1) - ucom_cons_tx_high + ucom_cons_tx_low;
1394 	temp %= UCOM_CONS_BUFSIZE;
1395 
1396 	if (temp) {
1397 		ucom_cons_tx_buf[ucom_cons_tx_high] = c;
1398 		ucom_cons_tx_high ++;
1399 		ucom_cons_tx_high %= UCOM_CONS_BUFSIZE;
1400 	}
1401 
1402 	/* start USB transfers */
1403 	ucom_outwakeup(sc->sc_tty);
1404 
1405 	mtx_unlock(sc->sc_mtx);
1406 
1407 	/* poll if necessary */
1408 	if (kdb_active && sc->sc_callback->ucom_poll) {
1409 		(sc->sc_callback->ucom_poll) (sc);
1410 		/* simple flow control */
1411 		if (temp == 0)
1412 			goto repeat;
1413 	}
1414 }
1415 
1416 #if defined(GDB)
1417 
1418 #include <gdb/gdb.h>
1419 
1420 static gdb_probe_f ucom_gdbprobe;
1421 static gdb_init_f ucom_gdbinit;
1422 static gdb_term_f ucom_gdbterm;
1423 static gdb_getc_f ucom_gdbgetc;
1424 static gdb_putc_f ucom_gdbputc;
1425 
1426 GDB_DBGPORT(sio, ucom_gdbprobe, ucom_gdbinit, ucom_gdbterm, ucom_gdbgetc, ucom_gdbputc);
1427 
1428 static int
1429 ucom_gdbprobe(void)
1430 {
1431 	return ((ucom_cons_softc != NULL) ? 0 : -1);
1432 }
1433 
1434 static void
1435 ucom_gdbinit(void)
1436 {
1437 }
1438 
1439 static void
1440 ucom_gdbterm(void)
1441 {
1442 }
1443 
1444 static void
1445 ucom_gdbputc(int c)
1446 {
1447         ucom_cnputc(NULL, c);
1448 }
1449 
1450 static int
1451 ucom_gdbgetc(void)
1452 {
1453         return (ucom_cngetc(NULL));
1454 }
1455 
1456 #endif
1457