xref: /netbsd-src/sys/dev/usb/ucom.c (revision 2e2322c9c07009df921d11b1268f8506affbb8ba)
1 /*	$NetBSD: ucom.c,v 1.118 2016/12/14 15:11:29 skrll Exp $	*/
2 
3 /*
4  * Copyright (c) 1998, 2000 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Lennart Augustsson (lennart@augustsson.net) at
9  * Carlstedt Research & Technology.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30  * POSSIBILITY OF SUCH DAMAGE.
31  */
32 /*
33  * This code is very heavily based on the 16550 driver, com.c.
34  */
35 
36 #include <sys/cdefs.h>
37 __KERNEL_RCSID(0, "$NetBSD: ucom.c,v 1.118 2016/12/14 15:11:29 skrll Exp $");
38 
39 #ifdef _KERNEL_OPT
40 #include "opt_usb.h"
41 #endif
42 
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/kernel.h>
46 #include <sys/ioctl.h>
47 #include <sys/conf.h>
48 #include <sys/tty.h>
49 #include <sys/file.h>
50 #include <sys/select.h>
51 #include <sys/proc.h>
52 #include <sys/vnode.h>
53 #include <sys/device.h>
54 #include <sys/poll.h>
55 #include <sys/queue.h>
56 #include <sys/kauth.h>
57 #include <sys/sysctl.h>
58 #include <sys/timepps.h>
59 #include <sys/rndsource.h>
60 
61 #include <dev/usb/usb.h>
62 
63 #include <dev/usb/usbdi.h>
64 #include <dev/usb/usbdi_util.h>
65 #include <dev/usb/usbdevs.h>
66 #include <dev/usb/usb_quirks.h>
67 #include <dev/usb/usbhist.h>
68 
69 #include <dev/usb/ucomvar.h>
70 
71 #include "ucom.h"
72 
73 #include "locators.h"
74 
75 #if NUCOM > 0
76 
77 #ifdef USB_DEBUG
78 #ifndef UCOM_DEBUG
79 #define ucomdebug 0
80 #else
81 int ucomdebug = 0;
82 
83 SYSCTL_SETUP(sysctl_hw_ucom_setup, "sysctl hw.ucom setup")
84 {
85 	int err;
86 	const struct sysctlnode *rnode;
87 	const struct sysctlnode *cnode;
88 
89 	err = sysctl_createv(clog, 0, NULL, &rnode,
90 	    CTLFLAG_PERMANENT, CTLTYPE_NODE, "ucom",
91 	    SYSCTL_DESCR("ucom global controls"),
92 	    NULL, 0, NULL, 0, CTL_HW, CTL_CREATE, CTL_EOL);
93 
94 	if (err)
95 		goto fail;
96 
97 	/* control debugging printfs */
98 	err = sysctl_createv(clog, 0, &rnode, &cnode,
99 	    CTLFLAG_PERMANENT|CTLFLAG_READWRITE, CTLTYPE_INT,
100 	    "debug", SYSCTL_DESCR("Enable debugging output"),
101 	    NULL, 0, &ucomdebug, sizeof(ucomdebug), CTL_CREATE, CTL_EOL);
102 	if (err)
103 		goto fail;
104 
105 	return;
106 fail:
107 	aprint_error("%s: sysctl_createv failed (err = %d)\n", __func__, err);
108 }
109 
110 #endif /* UCOM_DEBUG */
111 #endif /* USB_DEBUG */
112 
113 #define DPRINTF(FMT,A,B,C,D)    USBHIST_LOGN(ucomdebug,1,FMT,A,B,C,D)
114 #define DPRINTFN(N,FMT,A,B,C,D) USBHIST_LOGN(ucomdebug,N,FMT,A,B,C,D)
115 #define UCOMHIST_FUNC()         USBHIST_FUNC()
116 #define UCOMHIST_CALLED(name)   USBHIST_CALLED(ucomdebug)
117 
118 #define	UCOMCALLUNIT_MASK	TTCALLUNIT_MASK
119 #define	UCOMUNIT_MASK		TTUNIT_MASK
120 #define	UCOMDIALOUT_MASK	TTDIALOUT_MASK
121 
122 #define	UCOMCALLUNIT(x)		TTCALLUNIT(x)
123 #define	UCOMUNIT(x)		TTUNIT(x)
124 #define	UCOMDIALOUT(x)		TTDIALOUT(x)
125 
126 /*
127  * XXX: We can submit multiple input/output buffers to the usb stack
128  * to improve throughput, but the usb stack is too lame to deal with this
129  * in a number of places.
130  */
131 #define	UCOM_IN_BUFFS	1
132 #define	UCOM_OUT_BUFFS	1
133 
134 struct ucom_buffer {
135 	SIMPLEQ_ENTRY(ucom_buffer) ub_link;
136 	struct usbd_xfer *ub_xfer;
137 	u_char *ub_data;
138 	u_int ub_len;
139 	u_int ub_index;
140 };
141 
142 struct ucom_softc {
143 	device_t		sc_dev;		/* base device */
144 
145 	struct usbd_device *	sc_udev;	/* USB device */
146 	struct usbd_interface *	sc_iface;	/* data interface */
147 
148 	int			sc_bulkin_no;	/* bulk in endpoint address */
149 	struct usbd_pipe *	sc_bulkin_pipe;/* bulk in pipe */
150 	u_int			sc_ibufsize;	/* read buffer size */
151 	u_int			sc_ibufsizepad;	/* read buffer size padded */
152 	struct ucom_buffer	sc_ibuff[UCOM_IN_BUFFS];
153 	SIMPLEQ_HEAD(, ucom_buffer) sc_ibuff_empty;
154 	SIMPLEQ_HEAD(, ucom_buffer) sc_ibuff_full;
155 
156 	int			sc_bulkout_no;	/* bulk out endpoint address */
157 	struct usbd_pipe *	sc_bulkout_pipe;/* bulk out pipe */
158 	u_int			sc_obufsize;	/* write buffer size */
159 	u_int			sc_opkthdrlen;	/* header length of */
160 	struct ucom_buffer	sc_obuff[UCOM_OUT_BUFFS];
161 	SIMPLEQ_HEAD(, ucom_buffer) sc_obuff_free;
162 	SIMPLEQ_HEAD(, ucom_buffer) sc_obuff_full;
163 
164 	void			*sc_si;
165 
166 	const struct ucom_methods *sc_methods;
167 	void                    *sc_parent;
168 	int			sc_portno;
169 
170 	struct tty		*sc_tty;	/* our tty */
171 	u_char			sc_lsr;
172 	u_char			sc_msr;
173 	u_char			sc_mcr;
174 	volatile u_char		sc_rx_stopped;
175 	u_char			sc_rx_unblock;
176 	u_char			sc_tx_stopped;
177 	int			sc_swflags;
178 
179 	enum ucom_state {
180 	    UCOM_DEAD,
181 	    UCOM_ATTACHED,
182 	    UCOM_OPENING,
183 	    UCOM_CLOSING,
184 	    UCOM_OPEN
185 	}			sc_state;
186 	int			sc_refcnt;
187 	bool			sc_dying;	/* disconnecting */
188 
189 	struct pps_state	sc_pps_state;	/* pps state */
190 
191 	krndsource_t		sc_rndsource;	/* random source */
192 
193 	kmutex_t		sc_lock;
194 	kcondvar_t		sc_statecv;
195 	kcondvar_t		sc_detachcv;
196 };
197 
198 dev_type_open(ucomopen);
199 dev_type_close(ucomclose);
200 dev_type_read(ucomread);
201 dev_type_write(ucomwrite);
202 dev_type_ioctl(ucomioctl);
203 dev_type_stop(ucomstop);
204 dev_type_tty(ucomtty);
205 dev_type_poll(ucompoll);
206 
207 const struct cdevsw ucom_cdevsw = {
208 	.d_open = ucomopen,
209 	.d_close = ucomclose,
210 	.d_read = ucomread,
211 	.d_write = ucomwrite,
212 	.d_ioctl = ucomioctl,
213 	.d_stop = ucomstop,
214 	.d_tty = ucomtty,
215 	.d_poll = ucompoll,
216 	.d_mmap = nommap,
217 	.d_kqfilter = ttykqfilter,
218 	.d_discard = nodiscard,
219 	.d_flag = D_TTY | D_MPSAFE
220 };
221 
222 static void	ucom_cleanup(struct ucom_softc *);
223 static int	ucomparam(struct tty *, struct termios *);
224 static int	ucomhwiflow(struct tty *, int);
225 static void	ucomstart(struct tty *);
226 static void	ucom_shutdown(struct ucom_softc *);
227 static int	ucom_do_ioctl(struct ucom_softc *, u_long, void *,
228 			      int, struct lwp *);
229 static void	ucom_dtr(struct ucom_softc *, int);
230 static void	ucom_rts(struct ucom_softc *, int);
231 static void	ucom_break(struct ucom_softc *, int);
232 static void	tiocm_to_ucom(struct ucom_softc *, u_long, int);
233 static int	ucom_to_tiocm(struct ucom_softc *);
234 
235 static void	ucomreadcb(struct usbd_xfer *, void *, usbd_status);
236 static void	ucom_submit_write(struct ucom_softc *, struct ucom_buffer *);
237 static void	ucom_write_status(struct ucom_softc *, struct ucom_buffer *,
238 		    usbd_status);
239 
240 static void	ucomwritecb(struct usbd_xfer *, void *, usbd_status);
241 static void	ucom_read_complete(struct ucom_softc *);
242 static int	ucomsubmitread(struct ucom_softc *, struct ucom_buffer *);
243 static void	ucom_softintr(void *);
244 
245 int ucom_match(device_t, cfdata_t, void *);
246 void ucom_attach(device_t, device_t, void *);
247 int ucom_detach(device_t, int);
248 int ucom_activate(device_t, enum devact);
249 extern struct cfdriver ucom_cd;
250 CFATTACH_DECL_NEW(ucom, sizeof(struct ucom_softc), ucom_match, ucom_attach,
251     ucom_detach, ucom_activate);
252 
253 int
254 ucom_match(device_t parent, cfdata_t match, void *aux)
255 {
256 	return 1;
257 }
258 
259 void
260 ucom_attach(device_t parent, device_t self, void *aux)
261 {
262 	struct ucom_softc *sc = device_private(self);
263 	struct ucom_attach_args *ucaa = aux;
264 
265 	UCOMHIST_FUNC(); UCOMHIST_CALLED();
266 
267 	if (ucaa->ucaa_info != NULL)
268 		aprint_normal(": %s", ucaa->ucaa_info);
269 	aprint_normal("\n");
270 
271 	prop_dictionary_set_int32(device_properties(self), "port",
272 	    ucaa->ucaa_portno);
273 
274 	sc->sc_dev = self;
275 	sc->sc_udev = ucaa->ucaa_device;
276 	sc->sc_iface = ucaa->ucaa_iface;
277 	sc->sc_bulkout_no = ucaa->ucaa_bulkout;
278 	sc->sc_bulkin_no = ucaa->ucaa_bulkin;
279 	sc->sc_ibufsize = ucaa->ucaa_ibufsize;
280 	sc->sc_ibufsizepad = ucaa->ucaa_ibufsizepad;
281 	sc->sc_obufsize = ucaa->ucaa_obufsize;
282 	sc->sc_opkthdrlen = ucaa->ucaa_opkthdrlen;
283 	sc->sc_methods = ucaa->ucaa_methods;
284 	sc->sc_parent = ucaa->ucaa_arg;
285 	sc->sc_portno = ucaa->ucaa_portno;
286 
287 	sc->sc_lsr = 0;
288 	sc->sc_msr = 0;
289 	sc->sc_mcr = 0;
290 	sc->sc_tx_stopped = 0;
291 	sc->sc_swflags = 0;
292 	sc->sc_refcnt = 0;
293 	sc->sc_dying = false;
294 	sc->sc_state = UCOM_DEAD;
295 
296 	sc->sc_si = softint_establish(SOFTINT_USB, ucom_softintr, sc);
297 	mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_SOFTUSB);
298 	cv_init(&sc->sc_statecv, "ucomstate");
299 	cv_init(&sc->sc_detachcv, "ucomdtch");
300 
301 	SIMPLEQ_INIT(&sc->sc_ibuff_empty);
302 	SIMPLEQ_INIT(&sc->sc_ibuff_full);
303 	SIMPLEQ_INIT(&sc->sc_obuff_free);
304 	SIMPLEQ_INIT(&sc->sc_obuff_full);
305 
306 	memset(sc->sc_ibuff, 0, sizeof(sc->sc_ibuff));
307 	memset(sc->sc_obuff, 0, sizeof(sc->sc_obuff));
308 
309 	DPRINTF("open pipes in=%d out=%d", sc->sc_bulkin_no, sc->sc_bulkout_no,
310 	    0, 0);
311 
312 	struct ucom_buffer *ub;
313 	usbd_status err;
314 	int error;
315 
316 	/* Open the bulk pipes */
317 	err = usbd_open_pipe(sc->sc_iface, sc->sc_bulkin_no,
318 	    USBD_EXCLUSIVE_USE, &sc->sc_bulkin_pipe);
319 	if (err) {
320 		DPRINTF("open bulk in error (addr %d), err=%d",
321 		    sc->sc_bulkin_no, err, 0, 0);
322 		error = EIO;
323 		goto fail_0;
324 	}
325 	/* Allocate input buffers */
326 	for (ub = &sc->sc_ibuff[0]; ub != &sc->sc_ibuff[UCOM_IN_BUFFS];
327 	    ub++) {
328 		error = usbd_create_xfer(sc->sc_bulkin_pipe,
329 		    sc->sc_ibufsizepad, USBD_SHORT_XFER_OK, 0,
330 		    &ub->ub_xfer);
331 		if (error)
332 			goto fail_1;
333 		ub->ub_data = usbd_get_buffer(ub->ub_xfer);
334 	}
335 
336 	err = usbd_open_pipe(sc->sc_iface, sc->sc_bulkout_no,
337 	    USBD_EXCLUSIVE_USE, &sc->sc_bulkout_pipe);
338 	if (err) {
339 		DPRINTF("open bulk out error (addr %d), err=%d",
340 		    sc->sc_bulkout_no, err, 0, 0);
341 		error = EIO;
342 		goto fail_1;
343 	}
344 	for (ub = &sc->sc_obuff[0]; ub != &sc->sc_obuff[UCOM_OUT_BUFFS];
345 	    ub++) {
346 		error = usbd_create_xfer(sc->sc_bulkout_pipe,
347 		    sc->sc_obufsize, 0, 0, &ub->ub_xfer);
348 		if (error)
349 			goto fail_2;
350 		ub->ub_data = usbd_get_buffer(ub->ub_xfer);
351 		SIMPLEQ_INSERT_TAIL(&sc->sc_obuff_free, ub, ub_link);
352 	}
353 
354 	struct tty *tp = tty_alloc();
355 	tp->t_oproc = ucomstart;
356 	tp->t_param = ucomparam;
357 	tp->t_hwiflow = ucomhwiflow;
358 	sc->sc_tty = tp;
359 
360 	DPRINTF("tty_attach %p", tp, 0, 0, 0);
361 	tty_attach(tp);
362 
363 	rnd_attach_source(&sc->sc_rndsource, device_xname(sc->sc_dev),
364 			  RND_TYPE_TTY, RND_FLAG_DEFAULT);
365 
366 	if (!pmf_device_register(self, NULL, NULL))
367 		aprint_error_dev(self, "couldn't establish power handler\n");
368 
369 	sc->sc_state = UCOM_ATTACHED;
370 
371 	return;
372 
373 fail_2:
374 	for (ub = &sc->sc_obuff[0]; ub != &sc->sc_obuff[UCOM_OUT_BUFFS];
375 	    ub++) {
376 		if (ub->ub_xfer)
377 			usbd_destroy_xfer(ub->ub_xfer);
378 	}
379 
380 	usbd_close_pipe(sc->sc_bulkout_pipe);
381 
382 fail_1:
383 	for (ub = &sc->sc_ibuff[0]; ub != &sc->sc_ibuff[UCOM_IN_BUFFS];
384 	    ub++) {
385 		if (ub->ub_xfer)
386 			usbd_destroy_xfer(ub->ub_xfer);
387 	}
388 	usbd_close_pipe(sc->sc_bulkin_pipe);
389 
390 fail_0:
391 	aprint_error_dev(self, "attach failed, error=%d\n", error);
392 
393 	return;
394 }
395 
396 int
397 ucom_detach(device_t self, int flags)
398 {
399 	struct ucom_softc *sc = device_private(self);
400 	struct tty *tp = sc->sc_tty;
401 	int maj, mn;
402 	int i;
403 
404 	UCOMHIST_FUNC(); UCOMHIST_CALLED();
405 
406 	DPRINTF("sc=%p flags=%d tp=%p", sc, flags, tp, 0);
407 	DPRINTF("... pipe=%d,%d", sc->sc_bulkin_no, sc->sc_bulkout_no, 0, 0);
408 
409 	mutex_enter(&sc->sc_lock);
410 	sc->sc_dying = true;
411 	mutex_exit(&sc->sc_lock);
412 
413 	pmf_device_deregister(self);
414 
415 	if (sc->sc_bulkin_pipe != NULL)
416 		usbd_abort_pipe(sc->sc_bulkin_pipe);
417 	if (sc->sc_bulkout_pipe != NULL)
418 		usbd_abort_pipe(sc->sc_bulkout_pipe);
419 
420 	mutex_enter(&sc->sc_lock);
421 
422 	/* wait for open/close to finish */
423 	while (sc->sc_state == UCOM_OPENING || sc->sc_state == UCOM_CLOSING) {
424 		int error = cv_wait_sig(&sc->sc_statecv, &sc->sc_lock);
425 
426 		if (error) {
427 			mutex_exit(&sc->sc_lock);
428 			return error;
429 		}
430 	}
431 
432 	sc->sc_refcnt--;
433 	while (sc->sc_refcnt > 0) {
434 		/* Wake up anyone waiting */
435 		if (tp != NULL) {
436 			mutex_spin_enter(&tty_lock);
437 			CLR(tp->t_state, TS_CARR_ON);
438 			CLR(tp->t_cflag, CLOCAL | MDMBUF);
439 			ttyflush(tp, FREAD|FWRITE);
440 			mutex_spin_exit(&tty_lock);
441 		}
442 		/* Wait for processes to go away. */
443 		if (cv_timedwait(&sc->sc_detachcv, &sc->sc_lock, hz * 60)) {
444 			printf("%s: %s didn't detach\n", __func__,
445 			    device_xname(sc->sc_dev));
446 		}
447 	}
448 
449 	softint_disestablish(sc->sc_si);
450 	mutex_exit(&sc->sc_lock);
451 
452 	/* locate the major number */
453 	maj = cdevsw_lookup_major(&ucom_cdevsw);
454 
455 	/* Nuke the vnodes for any open instances. */
456 	mn = device_unit(self);
457 	DPRINTF("maj=%d mn=%d", maj, mn, 0, 0);
458 	vdevgone(maj, mn, mn, VCHR);
459 	vdevgone(maj, mn | UCOMDIALOUT_MASK, mn | UCOMDIALOUT_MASK, VCHR);
460 	vdevgone(maj, mn | UCOMCALLUNIT_MASK, mn | UCOMCALLUNIT_MASK, VCHR);
461 
462 	/* Detach and free the tty. */
463 	if (tp != NULL) {
464 		tty_detach(tp);
465 		tty_free(tp);
466 		sc->sc_tty = NULL;
467 	}
468 
469 	for (i = 0; i < UCOM_IN_BUFFS; i++) {
470 		if (sc->sc_ibuff[i].ub_xfer != NULL)
471 			usbd_destroy_xfer(sc->sc_ibuff[i].ub_xfer);
472 	}
473 
474 	for (i = 0; i < UCOM_OUT_BUFFS; i++) {
475 		if (sc->sc_obuff[i].ub_xfer != NULL)
476 			usbd_destroy_xfer(sc->sc_obuff[i].ub_xfer);
477 	}
478 
479 	if (sc->sc_bulkin_pipe != NULL) {
480 		usbd_close_pipe(sc->sc_bulkin_pipe);
481 		sc->sc_bulkin_pipe = NULL;
482 	}
483 
484 	if (sc->sc_bulkout_pipe != NULL) {
485 		usbd_close_pipe(sc->sc_bulkout_pipe);
486 		sc->sc_bulkout_pipe = NULL;
487 	}
488 
489 	/* Detach the random source */
490 	rnd_detach_source(&sc->sc_rndsource);
491 
492 	mutex_destroy(&sc->sc_lock);
493 	cv_destroy(&sc->sc_statecv);
494 	cv_destroy(&sc->sc_detachcv);
495 
496 	return 0;
497 }
498 
499 int
500 ucom_activate(device_t self, enum devact act)
501 {
502 	struct ucom_softc *sc = device_private(self);
503 
504 	UCOMHIST_FUNC(); UCOMHIST_CALLED();
505 
506 	DPRINTFN(5, "%d", act, 0, 0, 0);
507 
508 	switch (act) {
509 	case DVACT_DEACTIVATE:
510 		mutex_enter(&sc->sc_lock);
511 		sc->sc_dying = true;
512 		mutex_exit(&sc->sc_lock);
513 		return 0;
514 	default:
515 		return EOPNOTSUPP;
516 	}
517 }
518 
519 void
520 ucom_shutdown(struct ucom_softc *sc)
521 {
522 	struct tty *tp = sc->sc_tty;
523 
524 	UCOMHIST_FUNC(); UCOMHIST_CALLED();
525 
526 	/*
527 	 * Hang up if necessary.  Wait a bit, so the other side has time to
528 	 * notice even if we immediately open the port again.
529 	 */
530 	if (ISSET(tp->t_cflag, HUPCL)) {
531 		ucom_dtr(sc, 0);
532 		/* XXX will only timeout */
533 		(void) kpause(ttclos, false, hz, NULL);
534 	}
535 }
536 
537 int
538 ucomopen(dev_t dev, int flag, int mode, struct lwp *l)
539 {
540 	const int unit = UCOMUNIT(dev);
541 	struct ucom_softc * const sc = device_lookup_private(&ucom_cd, unit);
542 	int error = 0;
543 
544 	UCOMHIST_FUNC(); UCOMHIST_CALLED();
545 
546 	if (sc == NULL)
547 		return ENXIO;
548 
549 	mutex_enter(&sc->sc_lock);
550 	if (sc->sc_dying) {
551 		DPRINTF("... dying", 0, 0, 0, 0);
552 		mutex_exit(&sc->sc_lock);
553 		return EIO;
554 	}
555 
556 	if (!device_is_active(sc->sc_dev)) {
557 		mutex_exit(&sc->sc_lock);
558 		return ENXIO;
559 	}
560 
561 	struct tty *tp = sc->sc_tty;
562 
563 	DPRINTF("unit=%d, tp=%p", unit, tp, 0, 0);
564 
565 	if (kauth_authorize_device_tty(l->l_cred, KAUTH_DEVICE_TTY_OPEN, tp)) {
566 		mutex_exit(&sc->sc_lock);
567 		return EBUSY;
568 	}
569 
570 	/*
571 	 * Wait while the device is initialized by the
572 	 * first opener or cleaned up by the last closer.
573 	 */
574 	while (sc->sc_state == UCOM_OPENING || sc->sc_state == UCOM_CLOSING) {
575 		error = cv_wait_sig(&sc->sc_statecv, &sc->sc_lock);
576 
577 		if (sc->sc_dying)
578 			error = EIO;
579 
580 		if (error) {
581 			mutex_exit(&sc->sc_lock);
582 			return error;
583 		}
584 	}
585 	enum ucom_state state = sc->sc_state;
586 
587 	KASSERTMSG(state == UCOM_OPEN || state == UCOM_ATTACHED,
588 	    "state is %d", state);
589 
590 	bool cleanup = false;
591 	/* If this is the first open then perform the initialisation */
592 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
593 		KASSERT(state == UCOM_ATTACHED);
594 		tp->t_dev = dev;
595 		cleanup = true;
596 		sc->sc_state = UCOM_OPENING;
597 
598 		mutex_exit(&sc->sc_lock);
599 		if (sc->sc_methods->ucom_open != NULL) {
600 			error = sc->sc_methods->ucom_open(sc->sc_parent,
601 			    sc->sc_portno);
602 			if (error) {
603 				goto fail_2;
604 			}
605 		}
606 
607 		ucom_status_change(sc);
608 
609 		/* Clear PPS capture state on first open. */
610 		mutex_spin_enter(&timecounter_lock);
611 		memset(&sc->sc_pps_state, 0, sizeof(sc->sc_pps_state));
612 		sc->sc_pps_state.ppscap = PPS_CAPTUREASSERT | PPS_CAPTURECLEAR;
613 		pps_init(&sc->sc_pps_state);
614 		mutex_spin_exit(&timecounter_lock);
615 
616 		/*
617 		 * Initialize the termios status to the defaults.  Add in the
618 		 * sticky bits from TIOCSFLAGS.
619 		 */
620 		struct termios t;
621 
622 		t.c_ispeed = 0;
623 		t.c_ospeed = TTYDEF_SPEED;
624 		t.c_cflag = TTYDEF_CFLAG;
625 		if (ISSET(sc->sc_swflags, TIOCFLAG_CLOCAL))
626 			SET(t.c_cflag, CLOCAL);
627 		if (ISSET(sc->sc_swflags, TIOCFLAG_CRTSCTS))
628 			SET(t.c_cflag, CRTSCTS);
629 		if (ISSET(sc->sc_swflags, TIOCFLAG_MDMBUF))
630 			SET(t.c_cflag, MDMBUF);
631 		/* Make sure ucomparam() will do something. */
632 		tp->t_ospeed = 0;
633 		(void) ucomparam(tp, &t);
634 		tp->t_iflag = TTYDEF_IFLAG;
635 		tp->t_oflag = TTYDEF_OFLAG;
636 		tp->t_lflag = TTYDEF_LFLAG;
637 		ttychars(tp);
638 		ttsetwater(tp);
639 
640 		/*
641 		 * Turn on DTR.  We must always do this, even if carrier is not
642 		 * present, because otherwise we'd have to use TIOCSDTR
643 		 * immediately after setting CLOCAL, which applications do not
644 		 * expect.  We always assert DTR while the device is open
645 		 * unless explicitly requested to deassert it.  Ditto RTS.
646 		 */
647 		ucom_dtr(sc, 1);
648 		ucom_rts(sc, 1);
649 
650 		mutex_enter(&sc->sc_lock);
651 		if (sc->sc_dying) {
652 			DPRINTF("... dying", 0, 0, 0, 0);
653 			error = EIO;
654 			goto fail_1;
655 		}
656 
657 		sc->sc_rx_unblock = 0;
658 		sc->sc_rx_stopped = 0;
659 		sc->sc_tx_stopped = 0;
660 
661 		for (size_t i = 0; i < UCOM_IN_BUFFS; i++) {
662 			struct ucom_buffer *ub = &sc->sc_ibuff[i];
663 			error = ucomsubmitread(sc, ub);
664 			if (error) {
665 		    		mutex_exit(&sc->sc_lock);
666 				goto fail_2;
667 			}
668 		}
669 	}
670 	sc->sc_state = UCOM_OPEN;
671 	cv_signal(&sc->sc_statecv);
672 	mutex_exit(&sc->sc_lock);
673 
674 	DPRINTF("unit=%d, tp=%p dialout %d nonblock %d", unit, tp,
675 	    !!UCOMDIALOUT(dev), !!ISSET(flag, O_NONBLOCK));
676 	error = ttyopen(tp, UCOMDIALOUT(dev), ISSET(flag, O_NONBLOCK));
677 	if (error)
678 		goto bad;
679 
680 	error = (*tp->t_linesw->l_open)(dev, tp);
681 	if (error)
682 		goto bad;
683 
684 	return 0;
685 
686 bad:
687 	cleanup = !ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0;
688 
689 fail_2:
690 	if (cleanup) {
691 		/*
692 		 * We failed to open the device, and nobody else had
693 		 * it opened.  Clean up the state as appropriate.
694 		 */
695 		ucom_cleanup(sc);
696 	}
697 
698 	mutex_enter(&sc->sc_lock);
699 
700 fail_1:
701 	sc->sc_state = state;
702 	cv_signal(&sc->sc_statecv);
703 	mutex_exit(&sc->sc_lock);
704 
705 	return error;
706 }
707 
708 int
709 ucomclose(dev_t dev, int flag, int mode, struct lwp *l)
710 {
711 	const int unit = UCOMUNIT(dev);
712 	struct ucom_softc *sc = device_lookup_private(&ucom_cd, unit);
713 	int error = 0;
714 
715 	UCOMHIST_FUNC(); UCOMHIST_CALLED();
716 
717 	DPRINTF("unit=%d", UCOMUNIT(dev), 0, 0, 0);
718 
719 	if (sc == NULL)
720 		return 0;
721 
722 	mutex_enter(&sc->sc_lock);
723 	if (sc->sc_dying) {
724 		DPRINTF("... dying", 0, 0, 0, 0);
725 		mutex_exit(&sc->sc_lock);
726 		return ENXIO;
727 	}
728 
729 	/*
730 	 * Wait until any opens/closes have finished
731 	 */
732 	while (sc->sc_state == UCOM_OPENING || sc->sc_state == UCOM_CLOSING) {
733 		error = cv_wait_sig(&sc->sc_statecv, &sc->sc_lock);
734 
735 		if (sc->sc_dying)
736 			error = EIO;
737 
738 		if (error) {
739 			mutex_exit(&sc->sc_lock);
740 			return error;
741 		}
742 	}
743 
744 	struct tty *tp = sc->sc_tty;
745 
746 	if (!ISSET(tp->t_state, TS_ISOPEN)) {
747 		KASSERT(sc->sc_state == UCOM_ATTACHED);
748 		mutex_exit(&sc->sc_lock);
749 		return 0;
750 	}
751 
752 	KASSERT(sc->sc_state == UCOM_OPEN);
753 	sc->sc_state = UCOM_CLOSING;
754 	mutex_exit(&sc->sc_lock);
755 
756 	(*tp->t_linesw->l_close)(tp, flag);
757 	ttyclose(tp);
758 
759 	/* state when we're done - default to open */
760 	enum ucom_state state = UCOM_OPEN;
761 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
762 		/*
763 		 * Although we got a last close, the device may still be in
764 		 * use; e.g. if this was the dialout node, and there are still
765 		 * processes waiting for carrier on the non-dialout node.
766 		 */
767 		ucom_cleanup(sc);
768 		if (sc->sc_methods->ucom_close != NULL)
769 			sc->sc_methods->ucom_close(sc->sc_parent,
770 			    sc->sc_portno);
771 		state = UCOM_ATTACHED;
772 	}
773 
774 	mutex_enter(&sc->sc_lock);
775 	sc->sc_state = state;
776 	cv_signal(&sc->sc_statecv);
777 	mutex_exit(&sc->sc_lock);
778 
779 	return error;
780 }
781 
782 int
783 ucomread(dev_t dev, struct uio *uio, int flag)
784 {
785 	const int unit = UCOMUNIT(dev);
786 	struct ucom_softc * const sc = device_lookup_private(&ucom_cd, unit);
787 	int error;
788 
789 	UCOMHIST_FUNC(); UCOMHIST_CALLED();
790 
791 	if (sc == NULL)
792 		return EIO;
793 
794 	mutex_enter(&sc->sc_lock);
795 	if (sc->sc_dying) {
796 		DPRINTF("... dying", 0, 0, 0, 0);
797 		mutex_exit(&sc->sc_lock);
798 		return EIO;
799 	}
800 
801 	struct tty *tp = sc->sc_tty;
802 
803 	sc->sc_refcnt++;
804 	mutex_exit(&sc->sc_lock);
805 
806 	error = ((*tp->t_linesw->l_read)(tp, uio, flag));
807 
808 	mutex_enter(&sc->sc_lock);
809 	if (--sc->sc_refcnt < 0)
810 		cv_broadcast(&sc->sc_detachcv);
811 	DPRINTF("unit=%d refcnt %d", UCOMUNIT(dev), sc->sc_refcnt, 0, 0);
812 	mutex_exit(&sc->sc_lock);
813 
814 	return error;
815 }
816 
817 int
818 ucomwrite(dev_t dev, struct uio *uio, int flag)
819 {
820 	const int unit = UCOMUNIT(dev);
821 	struct ucom_softc * const sc = device_lookup_private(&ucom_cd, unit);
822 	int error;
823 
824 	UCOMHIST_FUNC(); UCOMHIST_CALLED();
825 
826 	if (sc == NULL)
827 		return EIO;
828 
829 	mutex_enter(&sc->sc_lock);
830 	if (sc->sc_dying) {
831 		DPRINTF("... dying", 0, 0, 0, 0);
832 		mutex_exit(&sc->sc_lock);
833 		return EIO;
834 	}
835 
836 	struct tty *tp = sc->sc_tty;
837 
838 	sc->sc_refcnt++;
839 	mutex_exit(&sc->sc_lock);
840 
841 	error = ((*tp->t_linesw->l_write)(tp, uio, flag));
842 
843 	mutex_enter(&sc->sc_lock);
844 	if (--sc->sc_refcnt < 0)
845 		cv_broadcast(&sc->sc_detachcv);
846 	DPRINTF("unit=%d refcnt %d", UCOMUNIT(dev), sc->sc_refcnt, 0, 0);
847 	mutex_exit(&sc->sc_lock);
848 
849 	return error;
850 }
851 
852 int
853 ucompoll(dev_t dev, int events, struct lwp *l)
854 {
855 	const int unit = UCOMUNIT(dev);
856 	struct ucom_softc * const sc = device_lookup_private(&ucom_cd, unit);
857 
858 	UCOMHIST_FUNC(); UCOMHIST_CALLED();
859 
860 	if (sc == NULL)
861 		return POLLHUP;
862 
863 	mutex_enter(&sc->sc_lock);
864 	if (sc->sc_dying) {
865 		DPRINTF("... dying", 0, 0, 0, 0);
866 		mutex_exit(&sc->sc_lock);
867 		return POLLHUP;
868 	}
869 	struct tty *tp = sc->sc_tty;
870 
871 	sc->sc_refcnt++;
872 	mutex_exit(&sc->sc_lock);
873 
874 	int revents = ((*tp->t_linesw->l_poll)(tp, events, l));
875 
876 	mutex_enter(&sc->sc_lock);
877 	if (--sc->sc_refcnt < 0)
878 		cv_broadcast(&sc->sc_detachcv);
879 	DPRINTF("unit=%d refcnt %d", UCOMUNIT(dev), sc->sc_refcnt, 0, 0);
880 	mutex_exit(&sc->sc_lock);
881 
882 	return revents;
883 }
884 
885 struct tty *
886 ucomtty(dev_t dev)
887 {
888 	const int unit = UCOMUNIT(dev);
889 	struct ucom_softc * const sc = device_lookup_private(&ucom_cd, unit);
890 
891 	return sc != NULL ? sc->sc_tty : NULL;
892 }
893 
894 int
895 ucomioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
896 {
897 	const int unit = UCOMUNIT(dev);
898 	struct ucom_softc * const sc = device_lookup_private(&ucom_cd, unit);
899 	int error;
900 
901 	UCOMHIST_FUNC(); UCOMHIST_CALLED();
902 
903 	if (sc == NULL)
904 		return EIO;
905 
906 	mutex_enter(&sc->sc_lock);
907 	if (sc->sc_dying) {
908 		DPRINTF("... dying", 0, 0, 0, 0);
909 		mutex_exit(&sc->sc_lock);
910 		return EIO;
911 	}
912 
913 	sc->sc_refcnt++;
914 	mutex_exit(&sc->sc_lock);
915 
916 	error = ucom_do_ioctl(sc, cmd, data, flag, l);
917 
918 	mutex_enter(&sc->sc_lock);
919 	if (--sc->sc_refcnt < 0)
920 		cv_broadcast(&sc->sc_detachcv);
921 	DPRINTF("unit=%d refcnt %d", UCOMUNIT(dev), sc->sc_refcnt, 0, 0);
922 	mutex_exit(&sc->sc_lock);
923 
924 	return error;
925 }
926 
927 static int
928 ucom_do_ioctl(struct ucom_softc *sc, u_long cmd, void *data, int flag,
929     struct lwp *l)
930 {
931 	struct tty *tp = sc->sc_tty;
932 	int error;
933 
934 	UCOMHIST_FUNC(); UCOMHIST_CALLED();
935 
936 	DPRINTF("cmd=0x%08lx", cmd, 0, 0, 0);
937 
938 	error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, l);
939 	if (error != EPASSTHROUGH)
940 		return error;
941 
942 	error = ttioctl(tp, cmd, data, flag, l);
943 	if (error != EPASSTHROUGH)
944 		return error;
945 
946 	if (sc->sc_methods->ucom_ioctl != NULL) {
947 		error = sc->sc_methods->ucom_ioctl(sc->sc_parent,
948 		    sc->sc_portno, cmd, data, flag, l->l_proc);
949 		if (error != EPASSTHROUGH)
950 			return error;
951 	}
952 
953 	error = 0;
954 
955 	DPRINTF("our cmd=0x%08lx", cmd, 0, 0, 0);
956 
957 	switch (cmd) {
958 	case TIOCSBRK:
959 		ucom_break(sc, 1);
960 		break;
961 
962 	case TIOCCBRK:
963 		ucom_break(sc, 0);
964 		break;
965 
966 	case TIOCSDTR:
967 		ucom_dtr(sc, 1);
968 		break;
969 
970 	case TIOCCDTR:
971 		ucom_dtr(sc, 0);
972 		break;
973 
974 	case TIOCGFLAGS:
975 		mutex_enter(&sc->sc_lock);
976 		*(int *)data = sc->sc_swflags;
977 		mutex_exit(&sc->sc_lock);
978 		break;
979 
980 	case TIOCSFLAGS:
981 		error = kauth_authorize_device_tty(l->l_cred,
982 		    KAUTH_DEVICE_TTY_PRIVSET, tp);
983 		if (error)
984 			break;
985 		mutex_enter(&sc->sc_lock);
986 		sc->sc_swflags = *(int *)data;
987 		mutex_exit(&sc->sc_lock);
988 		break;
989 
990 	case TIOCMSET:
991 	case TIOCMBIS:
992 	case TIOCMBIC:
993 		tiocm_to_ucom(sc, cmd, *(int *)data);
994 		break;
995 
996 	case TIOCMGET:
997 		*(int *)data = ucom_to_tiocm(sc);
998 		break;
999 
1000 	case PPS_IOC_CREATE:
1001 	case PPS_IOC_DESTROY:
1002 	case PPS_IOC_GETPARAMS:
1003 	case PPS_IOC_SETPARAMS:
1004 	case PPS_IOC_GETCAP:
1005 	case PPS_IOC_FETCH:
1006 #ifdef PPS_SYNC
1007 	case PPS_IOC_KCBIND:
1008 #endif
1009 		mutex_spin_enter(&timecounter_lock);
1010 		error = pps_ioctl(cmd, data, &sc->sc_pps_state);
1011 		mutex_spin_exit(&timecounter_lock);
1012 		break;
1013 
1014 	default:
1015 		error = EPASSTHROUGH;
1016 		break;
1017 	}
1018 
1019 	return error;
1020 }
1021 
1022 static void
1023 tiocm_to_ucom(struct ucom_softc *sc, u_long how, int ttybits)
1024 {
1025 	u_char combits;
1026 
1027 	combits = 0;
1028 	if (ISSET(ttybits, TIOCM_DTR))
1029 		SET(combits, UMCR_DTR);
1030 	if (ISSET(ttybits, TIOCM_RTS))
1031 		SET(combits, UMCR_RTS);
1032 
1033 	mutex_enter(&sc->sc_lock);
1034 	switch (how) {
1035 	case TIOCMBIC:
1036 		CLR(sc->sc_mcr, combits);
1037 		break;
1038 
1039 	case TIOCMBIS:
1040 		SET(sc->sc_mcr, combits);
1041 		break;
1042 
1043 	case TIOCMSET:
1044 		CLR(sc->sc_mcr, UMCR_DTR | UMCR_RTS);
1045 		SET(sc->sc_mcr, combits);
1046 		break;
1047 	}
1048 	u_char mcr = sc->sc_mcr;
1049 	mutex_exit(&sc->sc_lock);
1050 
1051 	if (how == TIOCMSET || ISSET(combits, UMCR_DTR))
1052 		ucom_dtr(sc, (mcr & UMCR_DTR) != 0);
1053 	if (how == TIOCMSET || ISSET(combits, UMCR_RTS))
1054 		ucom_rts(sc, (mcr & UMCR_RTS) != 0);
1055 }
1056 
1057 static int
1058 ucom_to_tiocm(struct ucom_softc *sc)
1059 {
1060 	u_char combits;
1061 	int ttybits = 0;
1062 
1063 	mutex_enter(&sc->sc_lock);
1064 	combits = sc->sc_mcr;
1065 	if (ISSET(combits, UMCR_DTR))
1066 		SET(ttybits, TIOCM_DTR);
1067 	if (ISSET(combits, UMCR_RTS))
1068 		SET(ttybits, TIOCM_RTS);
1069 
1070 	combits = sc->sc_msr;
1071 	if (ISSET(combits, UMSR_DCD))
1072 		SET(ttybits, TIOCM_CD);
1073 	if (ISSET(combits, UMSR_CTS))
1074 		SET(ttybits, TIOCM_CTS);
1075 	if (ISSET(combits, UMSR_DSR))
1076 		SET(ttybits, TIOCM_DSR);
1077 	if (ISSET(combits, UMSR_RI | UMSR_TERI))
1078 		SET(ttybits, TIOCM_RI);
1079 
1080 #if 0
1081 XXX;
1082 	if (sc->sc_ier != 0)
1083 		SET(ttybits, TIOCM_LE);
1084 #endif
1085 	mutex_exit(&sc->sc_lock);
1086 
1087 	return ttybits;
1088 }
1089 
1090 static void
1091 ucom_break(struct ucom_softc *sc, int onoff)
1092 {
1093 	UCOMHIST_FUNC(); UCOMHIST_CALLED();
1094 
1095 	DPRINTF("onoff=%d", onoff, 0, 0, 0);
1096 
1097 	if (sc->sc_methods->ucom_set != NULL)
1098 		sc->sc_methods->ucom_set(sc->sc_parent, sc->sc_portno,
1099 		    UCOM_SET_BREAK, onoff);
1100 }
1101 
1102 static void
1103 ucom_dtr(struct ucom_softc *sc, int onoff)
1104 {
1105 	UCOMHIST_FUNC(); UCOMHIST_CALLED();
1106 
1107 	DPRINTF("onoff=%d", onoff, 0, 0, 0);
1108 
1109 	if (sc->sc_methods->ucom_set != NULL)
1110 		sc->sc_methods->ucom_set(sc->sc_parent, sc->sc_portno,
1111 		    UCOM_SET_DTR, onoff);
1112 }
1113 
1114 static void
1115 ucom_rts(struct ucom_softc *sc, int onoff)
1116 {
1117 	UCOMHIST_FUNC(); UCOMHIST_CALLED();
1118 
1119 	DPRINTF("onoff=%d", onoff, 0, 0, 0);
1120 
1121 	if (sc->sc_methods->ucom_set != NULL)
1122 		sc->sc_methods->ucom_set(sc->sc_parent, sc->sc_portno,
1123 		    UCOM_SET_RTS, onoff);
1124 }
1125 
1126 void
1127 ucom_status_change(struct ucom_softc *sc)
1128 {
1129 	struct tty *tp = sc->sc_tty;
1130 
1131 	if (sc->sc_methods->ucom_get_status != NULL) {
1132 		u_char msr, lsr;
1133 
1134 		sc->sc_methods->ucom_get_status(sc->sc_parent, sc->sc_portno,
1135 		    &lsr, &msr);
1136 		mutex_enter(&sc->sc_lock);
1137 		u_char old_msr = sc->sc_msr;
1138 
1139 		sc->sc_lsr = lsr;
1140 		sc->sc_msr = msr;
1141 		mutex_exit(&sc->sc_lock);
1142 
1143 		if (ISSET((msr ^ old_msr), UMSR_DCD)) {
1144 			mutex_spin_enter(&timecounter_lock);
1145 			pps_capture(&sc->sc_pps_state);
1146 			pps_event(&sc->sc_pps_state,
1147 			    (sc->sc_msr & UMSR_DCD) ?
1148 			    PPS_CAPTUREASSERT :
1149 			    PPS_CAPTURECLEAR);
1150 			mutex_spin_exit(&timecounter_lock);
1151 
1152 			(*tp->t_linesw->l_modem)(tp, ISSET(msr, UMSR_DCD));
1153 		}
1154 	} else {
1155 		mutex_enter(&sc->sc_lock);
1156 		sc->sc_lsr = 0;
1157 		/* Assume DCD is present, if we have no chance to check it. */
1158 		sc->sc_msr = UMSR_DCD;
1159 		mutex_exit(&sc->sc_lock);
1160 	}
1161 }
1162 
1163 static int
1164 ucomparam(struct tty *tp, struct termios *t)
1165 {
1166 	const int unit = UCOMUNIT(tp->t_dev);
1167 	struct ucom_softc * const sc = device_lookup_private(&ucom_cd, unit);
1168 	int error = 0;
1169 
1170 	UCOMHIST_FUNC(); UCOMHIST_CALLED();
1171 
1172 	if (sc == NULL)
1173 		return EIO;
1174 
1175 	mutex_enter(&sc->sc_lock);
1176 	if (sc->sc_dying) {
1177 		DPRINTF("... dying", 0, 0, 0, 0);
1178 		mutex_exit(&sc->sc_lock);
1179 		return EIO;
1180 	}
1181 
1182 	sc->sc_refcnt++;
1183 	mutex_exit(&sc->sc_lock);
1184 
1185 	/* Check requested parameters. */
1186 	if (t->c_ispeed && t->c_ispeed != t->c_ospeed) {
1187 		error = EINVAL;
1188 		goto out;
1189 	}
1190 
1191 	/*
1192 	 * For the console, always force CLOCAL and !HUPCL, so that the port
1193 	 * is always active.
1194 	 */
1195 	if (ISSET(sc->sc_swflags, TIOCFLAG_SOFTCAR)) {
1196 		SET(t->c_cflag, CLOCAL);
1197 		CLR(t->c_cflag, HUPCL);
1198 	}
1199 
1200 	/*
1201 	 * If there were no changes, don't do anything.  This avoids dropping
1202 	 * input and improves performance when all we did was frob things like
1203 	 * VMIN and VTIME.
1204 	 */
1205 	if (tp->t_ospeed == t->c_ospeed &&
1206 	    tp->t_cflag == t->c_cflag) {
1207 		goto out;
1208 	}
1209 
1210 	/* XXX lcr = ISSET(sc->sc_lcr, LCR_SBREAK) | cflag2lcr(t->c_cflag); */
1211 
1212 	/* And copy to tty. */
1213 	tp->t_ispeed = 0;
1214 	tp->t_ospeed = t->c_ospeed;
1215 	tp->t_cflag = t->c_cflag;
1216 
1217 	if (sc->sc_methods->ucom_param != NULL) {
1218 		error = sc->sc_methods->ucom_param(sc->sc_parent, sc->sc_portno,
1219 		    t);
1220 		if (error)
1221 			goto out;
1222 	}
1223 
1224 	/* XXX worry about CHWFLOW */
1225 
1226 	/*
1227 	 * Update the tty layer's idea of the carrier bit, in case we changed
1228 	 * CLOCAL or MDMBUF.  We don't hang up here; we only do that by
1229 	 * explicit request.
1230 	 */
1231 	DPRINTF("l_modem", 0, 0, 0, 0);
1232 	(void) (*tp->t_linesw->l_modem)(tp, ISSET(sc->sc_msr, UMSR_DCD));
1233 
1234 #if 0
1235 XXX what if the hardware is not open
1236 	if (!ISSET(t->c_cflag, CHWFLOW)) {
1237 		if (sc->sc_tx_stopped) {
1238 			sc->sc_tx_stopped = 0;
1239 			ucomstart(tp);
1240 		}
1241 	}
1242 #endif
1243 out:
1244 	mutex_enter(&sc->sc_lock);
1245 	if (--sc->sc_refcnt < 0)
1246 		cv_broadcast(&sc->sc_detachcv);
1247 	DPRINTF("unit=%d refcnt %d", UCOMUNIT(tp->t_dev), sc->sc_refcnt, 0, 0);
1248 
1249 	mutex_exit(&sc->sc_lock);
1250 
1251 	return 0;
1252 }
1253 
1254 static int
1255 ucomhwiflow(struct tty *tp, int block)
1256 {
1257 	const int unit = UCOMUNIT(tp->t_dev);
1258 	struct ucom_softc * const sc = device_lookup_private(&ucom_cd, unit);
1259 	int old;
1260 
1261 	UCOMHIST_FUNC(); UCOMHIST_CALLED();
1262 
1263 	if (sc == NULL)
1264 		return 0;
1265 
1266 	mutex_enter(&sc->sc_lock);
1267 	old = sc->sc_rx_stopped;
1268 	sc->sc_rx_stopped = (u_char)block;
1269 
1270 	if (old && !block) {
1271 		sc->sc_rx_unblock = 1;
1272 		softint_schedule(sc->sc_si);
1273 	}
1274 	mutex_exit(&sc->sc_lock);
1275 
1276 	return 1;
1277 }
1278 
1279 static void
1280 ucomstart(struct tty *tp)
1281 {
1282 	const int unit = UCOMUNIT(tp->t_dev);
1283 	struct ucom_softc * const sc = device_lookup_private(&ucom_cd, unit);
1284 	struct ucom_buffer *ub;
1285 	u_char *data;
1286 	int cnt;
1287 
1288 	UCOMHIST_FUNC(); UCOMHIST_CALLED();
1289 
1290 	if (sc == NULL)
1291 		return;
1292 
1293 	KASSERT(&sc->sc_lock);
1294 	KASSERT(mutex_owned(&tty_lock));
1295 	if (sc->sc_dying) {
1296 		DPRINTF("... dying", 0, 0, 0, 0);
1297 		return;
1298 	}
1299 
1300 	if (ISSET(tp->t_state, TS_BUSY | TS_TIMEOUT | TS_TTSTOP))
1301 		goto out;
1302 	if (sc->sc_tx_stopped)
1303 		goto out;
1304 
1305 	if (!ttypull(tp))
1306 		goto out;
1307 
1308 	/* Grab the first contiguous region of buffer space. */
1309 	data = tp->t_outq.c_cf;
1310 	cnt = ndqb(&tp->t_outq, 0);
1311 
1312 	if (cnt == 0)
1313 		goto out;
1314 
1315 	ub = SIMPLEQ_FIRST(&sc->sc_obuff_free);
1316 	if (ub == NULL) {
1317 		SET(tp->t_state, TS_BUSY);
1318 		goto out;
1319 	}
1320 
1321 	SIMPLEQ_REMOVE_HEAD(&sc->sc_obuff_free, ub_link);
1322 
1323 	if (SIMPLEQ_FIRST(&sc->sc_obuff_free) == NULL)
1324 		SET(tp->t_state, TS_BUSY);
1325 
1326 	if (cnt > sc->sc_obufsize)
1327 		cnt = sc->sc_obufsize;
1328 
1329 	if (sc->sc_methods->ucom_write != NULL)
1330 		sc->sc_methods->ucom_write(sc->sc_parent, sc->sc_portno,
1331 		    ub->ub_data, data, &cnt);
1332 	else
1333 		memcpy(ub->ub_data, data, cnt);
1334 
1335 	ub->ub_len = cnt;
1336 	ub->ub_index = 0;
1337 
1338 	SIMPLEQ_INSERT_TAIL(&sc->sc_obuff_full, ub, ub_link);
1339 
1340 	softint_schedule(sc->sc_si);
1341 
1342  out:
1343 	DPRINTF("... done", 0, 0, 0, 0);
1344 	return;
1345 }
1346 
1347 void
1348 ucomstop(struct tty *tp, int flag)
1349 {
1350 #if 0
1351 	const int unit = UCOMUNIT(tp->t_dev);
1352 	struct ucom_softc * const sc = device_lookup_private(&ucom_cd, unit);
1353 
1354 	mutex_enter(&sc->sc_lock);
1355 	mutex_spin_enter(&tty_lock);
1356 	if (ISSET(tp->t_state, TS_BUSY)) {
1357 		/* obuff_full -> obuff_free? */
1358 		/* sc->sc_tx_stopped = 1; */
1359 		if (!ISSET(tp->t_state, TS_TTSTOP))
1360 			SET(tp->t_state, TS_FLUSH);
1361 	}
1362 	mutex_spin_exit(&tty_lock);
1363 	mutex_exit(&sc->sc_lock);
1364 #endif
1365 }
1366 
1367 static void
1368 ucom_write_status(struct ucom_softc *sc, struct ucom_buffer *ub,
1369     usbd_status err)
1370 {
1371 	struct tty *tp = sc->sc_tty;
1372 	uint32_t cc = ub->ub_len;
1373 
1374 	KASSERT(mutex_owned(&sc->sc_lock));
1375 
1376 	switch (err) {
1377 	case USBD_IN_PROGRESS:
1378 		ub->ub_index = ub->ub_len;
1379 		break;
1380 	case USBD_STALLED:
1381 		ub->ub_index = 0;
1382 		softint_schedule(sc->sc_si);
1383 		break;
1384 	case USBD_NORMAL_COMPLETION:
1385 		usbd_get_xfer_status(ub->ub_xfer, NULL, NULL, &cc, NULL);
1386 		rnd_add_uint32(&sc->sc_rndsource, cc);
1387 		/*FALLTHROUGH*/
1388 	default:
1389 		SIMPLEQ_REMOVE_HEAD(&sc->sc_obuff_full, ub_link);
1390 		SIMPLEQ_INSERT_TAIL(&sc->sc_obuff_free, ub, ub_link);
1391 		cc -= sc->sc_opkthdrlen;
1392 
1393 		mutex_spin_enter(&tty_lock);
1394 		CLR(tp->t_state, TS_BUSY);
1395 		if (ISSET(tp->t_state, TS_FLUSH))
1396 			CLR(tp->t_state, TS_FLUSH);
1397 		else
1398 			ndflush(&tp->t_outq, cc);
1399 		mutex_spin_exit(&tty_lock);
1400 
1401 		if (err != USBD_CANCELLED && err != USBD_IOERROR &&
1402 		    !sc->sc_dying) {
1403 			if ((ub = SIMPLEQ_FIRST(&sc->sc_obuff_full)) != NULL)
1404 				ucom_submit_write(sc, ub);
1405 
1406 			mutex_spin_enter(&tty_lock);
1407 			(*tp->t_linesw->l_start)(tp);
1408 			mutex_spin_exit(&tty_lock);
1409 		}
1410 		break;
1411 	}
1412 }
1413 
1414 static void
1415 ucom_submit_write(struct ucom_softc *sc, struct ucom_buffer *ub)
1416 {
1417 
1418 	KASSERT(mutex_owned(&sc->sc_lock));
1419 
1420 	usbd_setup_xfer(ub->ub_xfer, sc, ub->ub_data, ub->ub_len,
1421 	    0, USBD_NO_TIMEOUT, ucomwritecb);
1422 
1423 	ucom_write_status(sc, ub, usbd_transfer(ub->ub_xfer));
1424 }
1425 
1426 static void
1427 ucomwritecb(struct usbd_xfer *xfer, void *p, usbd_status status)
1428 {
1429 	struct ucom_softc *sc = (struct ucom_softc *)p;
1430 
1431 	mutex_enter(&sc->sc_lock);
1432 	ucom_write_status(sc, SIMPLEQ_FIRST(&sc->sc_obuff_full), status);
1433 	mutex_exit(&sc->sc_lock);
1434 
1435 }
1436 
1437 static void
1438 ucom_softintr(void *arg)
1439 {
1440 	UCOMHIST_FUNC(); UCOMHIST_CALLED();
1441 
1442 	struct ucom_softc *sc = arg;
1443 
1444 	mutex_enter(&sc->sc_lock);
1445 	if (sc->sc_dying) {
1446 		DPRINTF("... dying", 0, 0, 0, 0);
1447 		mutex_exit(&sc->sc_lock);
1448 		return;
1449 	}
1450 
1451 	struct tty *tp = sc->sc_tty;
1452 	mutex_enter(&tty_lock);
1453 	if (!ISSET(tp->t_state, TS_ISOPEN)) {
1454 		mutex_exit(&tty_lock);
1455 		mutex_exit(&sc->sc_lock);
1456 		return;
1457 	}
1458 	mutex_exit(&tty_lock);
1459 
1460 	struct ucom_buffer *ub = SIMPLEQ_FIRST(&sc->sc_obuff_full);
1461 
1462 	if (ub != NULL && ub->ub_index == 0)
1463 		ucom_submit_write(sc, ub);
1464 
1465 	if (sc->sc_rx_unblock)
1466 		ucom_read_complete(sc);
1467 
1468 	mutex_exit(&sc->sc_lock);
1469 }
1470 
1471 static void
1472 ucom_read_complete(struct ucom_softc *sc)
1473 {
1474 	int (*rint)(int, struct tty *);
1475 	struct ucom_buffer *ub;
1476 	struct tty *tp;
1477 
1478 	KASSERT(mutex_owned(&sc->sc_lock));
1479 
1480 	tp = sc->sc_tty;
1481 	rint = tp->t_linesw->l_rint;
1482 	ub = SIMPLEQ_FIRST(&sc->sc_ibuff_full);
1483 
1484 	while (ub != NULL && !sc->sc_rx_stopped) {
1485 
1486 		/* XXX ttyinput takes tty_lock */
1487 		while (ub->ub_index < ub->ub_len && !sc->sc_rx_stopped) {
1488 			/* Give characters to tty layer. */
1489 			if ((*rint)(ub->ub_data[ub->ub_index], tp) == -1) {
1490 				/* Overflow: drop remainder */
1491 				ub->ub_index = ub->ub_len;
1492 			} else
1493 				ub->ub_index++;
1494 		}
1495 
1496 		if (ub->ub_index == ub->ub_len) {
1497 			SIMPLEQ_REMOVE_HEAD(&sc->sc_ibuff_full, ub_link);
1498 
1499 			sc->sc_refcnt--;
1500 			/* increments sc_refcnt */
1501 			ucomsubmitread(sc, ub);
1502 
1503 			ub = SIMPLEQ_FIRST(&sc->sc_ibuff_full);
1504 		}
1505 	}
1506 
1507 	sc->sc_rx_unblock = (ub != NULL);
1508 }
1509 
1510 static int
1511 ucomsubmitread(struct ucom_softc *sc, struct ucom_buffer *ub)
1512 {
1513 	usbd_status err;
1514 
1515 	KASSERT(mutex_owned(&sc->sc_lock));
1516 
1517 	usbd_setup_xfer(ub->ub_xfer, sc, ub->ub_data, sc->sc_ibufsize,
1518 	    USBD_SHORT_XFER_OK, USBD_NO_TIMEOUT, ucomreadcb);
1519 
1520 	if ((err = usbd_transfer(ub->ub_xfer)) != USBD_IN_PROGRESS) {
1521 		/* XXX: Recover from this, please! */
1522 		printf("%s: err=%s\n", __func__, usbd_errstr(err));
1523 		return EIO;
1524 	}
1525 
1526 	sc->sc_refcnt++;
1527 
1528 	SIMPLEQ_INSERT_TAIL(&sc->sc_ibuff_empty, ub, ub_link);
1529 
1530 	return 0;
1531 }
1532 
1533 static void
1534 ucomreadcb(struct usbd_xfer *xfer, void *p, usbd_status status)
1535 {
1536 	struct ucom_softc *sc = (struct ucom_softc *)p;
1537 	struct ucom_buffer *ub;
1538 	uint32_t cc;
1539 	u_char *cp;
1540 
1541 	UCOMHIST_FUNC(); UCOMHIST_CALLED();
1542 
1543 	mutex_enter(&sc->sc_lock);
1544 
1545 	struct tty *tp = sc->sc_tty;
1546 
1547 	if (status == USBD_CANCELLED || status == USBD_IOERROR ||
1548 	    sc->sc_dying) {
1549 
1550 		DPRINTF("... done (status %d dying %d)", status, sc->sc_dying,
1551 		    0, 0);
1552 
1553 		if (status == USBD_IOERROR || sc->sc_dying) {
1554 			/* Send something to wake upper layer */
1555 			(tp->t_linesw->l_rint)('\n', tp);
1556 			mutex_spin_enter(&tty_lock);	/* XXX */
1557 			ttwakeup(tp);
1558 			mutex_spin_exit(&tty_lock);	/* XXX */
1559 		}
1560 
1561 		if (--sc->sc_refcnt < 0)
1562 			cv_broadcast(&sc->sc_detachcv);
1563 		DPRINTF("unit=%d refcnt %d", UCOMUNIT(tp->t_dev), sc->sc_refcnt,
1564 		    0, 0);
1565 		mutex_exit(&sc->sc_lock);
1566 
1567 		return;
1568 	}
1569 
1570 	ub = SIMPLEQ_FIRST(&sc->sc_ibuff_empty);
1571 	SIMPLEQ_REMOVE_HEAD(&sc->sc_ibuff_empty, ub_link);
1572 
1573 	if (status != USBD_NORMAL_COMPLETION) {
1574 		if (status == USBD_STALLED) {
1575 			usbd_clear_endpoint_stall_async(sc->sc_bulkin_pipe);
1576 		} else {
1577 			printf("ucomreadcb: wonky status=%s\n",
1578 			    usbd_errstr(status));
1579 		}
1580 
1581 		DPRINTF("... done (status %d)", status, 0, 0, 0);
1582 		sc->sc_refcnt--;
1583 		/* re-adds ub to sc_ibuff_empty and increments sc_refcnt */
1584 		ucomsubmitread(sc, ub);
1585 		mutex_exit(&sc->sc_lock);
1586 		return;
1587 	}
1588 
1589 	usbd_get_xfer_status(xfer, NULL, (void *)&cp, &cc, NULL);
1590 
1591 #ifdef UCOM_DEBUG
1592 	/* This is triggered by uslsa(4) occasionally. */
1593 	if ((ucomdebug > 0) && (cc == 0)) {
1594 		device_printf(sc->sc_dev, "ucomreadcb: zero length xfer!\n");
1595 	}
1596 #endif
1597 	KDASSERT(cp == ub->ub_data);
1598 
1599 	rnd_add_uint32(&sc->sc_rndsource, cc);
1600 
1601 	if (sc->sc_state != UCOM_OPEN) {
1602 		/* Go around again - we're not quite ready */
1603 		sc->sc_refcnt--;
1604 		/* re-adds ub to sc_ibuff_empty and increments sc_refcnt */
1605 		ucomsubmitread(sc, ub);
1606 		mutex_exit(&sc->sc_lock);
1607 		DPRINTF("... done (not open)", 0, 0, 0, 0);
1608 		return;
1609 	}
1610 
1611 	mutex_exit(&sc->sc_lock);
1612 	if (sc->sc_methods->ucom_read != NULL) {
1613 		sc->sc_methods->ucom_read(sc->sc_parent, sc->sc_portno,
1614 		    &cp, &cc);
1615 		ub->ub_index = (u_int)(cp - ub->ub_data);
1616 	} else
1617 		ub->ub_index = 0;
1618 
1619 	ub->ub_len = cc;
1620 
1621 	mutex_enter(&sc->sc_lock);
1622 	if (sc->sc_dying) {
1623 		if (--sc->sc_refcnt < 0)
1624 			cv_broadcast(&sc->sc_detachcv);
1625 		mutex_exit(&sc->sc_lock);
1626 		DPRINTF("... dying", 0, 0, 0, 0);
1627 		return;
1628 	}
1629 
1630 	SIMPLEQ_INSERT_TAIL(&sc->sc_ibuff_full, ub, ub_link);
1631 
1632 	ucom_read_complete(sc);
1633 	mutex_exit(&sc->sc_lock);
1634 
1635 	DPRINTF("... done", 0, 0, 0, 0);
1636 }
1637 
1638 static void
1639 ucom_cleanup(struct ucom_softc *sc)
1640 {
1641 
1642 	UCOMHIST_FUNC(); UCOMHIST_CALLED();
1643 
1644 	DPRINTF("aborting pipes", 0, 0, 0, 0);
1645 
1646 	mutex_enter(&sc->sc_lock);
1647 
1648 	/* If we're dying then the detach routine will abort our pipes, etc */
1649 	if (sc->sc_dying) {
1650 		DPRINTF("... dying", 0, 0, 0, 0);
1651 
1652 		mutex_exit(&sc->sc_lock);
1653 		return;
1654 	}
1655 
1656 	mutex_exit(&sc->sc_lock);
1657 
1658 	ucom_shutdown(sc);
1659 
1660 	if (sc->sc_bulkin_pipe != NULL) {
1661 		usbd_abort_pipe(sc->sc_bulkin_pipe);
1662 	}
1663 	if (sc->sc_bulkout_pipe != NULL) {
1664 		usbd_abort_pipe(sc->sc_bulkout_pipe);
1665 	}
1666 }
1667 
1668 #endif /* NUCOM > 0 */
1669 
1670 int
1671 ucomprint(void *aux, const char *pnp)
1672 {
1673 	struct ucom_attach_args *ucaa = aux;
1674 
1675 	if (pnp)
1676 		aprint_normal("ucom at %s", pnp);
1677 	if (ucaa->ucaa_portno != UCOM_UNK_PORTNO)
1678 		aprint_normal(" portno %d", ucaa->ucaa_portno);
1679 	return UNCONF;
1680 }
1681 
1682 int
1683 ucomsubmatch(device_t parent, cfdata_t cf,
1684 	     const int *ldesc, void *aux)
1685 {
1686 	struct ucom_attach_args *ucaa = aux;
1687 
1688 	if (ucaa->ucaa_portno != UCOM_UNK_PORTNO &&
1689 	    cf->cf_loc[UCOMBUSCF_PORTNO] != UCOMBUSCF_PORTNO_DEFAULT &&
1690 	    cf->cf_loc[UCOMBUSCF_PORTNO] != ucaa->ucaa_portno)
1691 		return 0;
1692 	return config_match(parent, cf, aux);
1693 }
1694