xref: /netbsd-src/sys/dev/usb/ucom.c (revision 2dd295436a0082eb4f8d294f4aa73c223413d0f2)
1 /*	$NetBSD: ucom.c,v 1.138 2023/03/05 23:28:54 riastradh 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 1.138 2023/03/05 23:28:54 riastradh 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 #include "locators.h"
73 #include "ioconf.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 #define	ucom_unit		tty_unit
126 
127 /*
128  * XXX: We can submit multiple input/output buffers to the usb stack
129  * to improve throughput, but the usb stack is too lame to deal with this
130  * in a number of places.
131  */
132 #define	UCOM_IN_BUFFS	1
133 #define	UCOM_OUT_BUFFS	1
134 
135 struct ucom_buffer {
136 	SIMPLEQ_ENTRY(ucom_buffer) ub_link;
137 	struct usbd_xfer *ub_xfer;
138 	u_char *ub_data;
139 	u_int ub_len;
140 	u_int ub_index;
141 };
142 
143 struct ucom_softc {
144 	device_t		sc_dev;		/* base device */
145 
146 	struct usbd_device *	sc_udev;	/* USB device */
147 	struct usbd_interface *	sc_iface;	/* data interface */
148 
149 	int			sc_bulkin_no;	/* bulk in endpoint address */
150 	struct usbd_pipe *	sc_bulkin_pipe;/* bulk in pipe */
151 	u_int			sc_ibufsize;	/* read buffer size */
152 	u_int			sc_ibufsizepad;	/* read buffer size padded */
153 	struct ucom_buffer	sc_ibuff[UCOM_IN_BUFFS];
154 	SIMPLEQ_HEAD(, ucom_buffer) sc_ibuff_empty;
155 	SIMPLEQ_HEAD(, ucom_buffer) sc_ibuff_full;
156 
157 	int			sc_bulkout_no;	/* bulk out endpoint address */
158 	struct usbd_pipe *	sc_bulkout_pipe;/* bulk out pipe */
159 	u_int			sc_obufsize;	/* write buffer size */
160 	u_int			sc_opkthdrlen;	/* header length of */
161 	struct ucom_buffer	sc_obuff[UCOM_OUT_BUFFS];
162 	SIMPLEQ_HEAD(, ucom_buffer) sc_obuff_free;
163 	SIMPLEQ_HEAD(, ucom_buffer) sc_obuff_full;
164 
165 	void			*sc_si;
166 
167 	const struct ucom_methods *sc_methods;
168 	void                    *sc_parent;
169 	int			sc_portno;
170 
171 	struct tty		*sc_tty;	/* our tty */
172 	u_char			sc_lsr;
173 	u_char			sc_msr;
174 	u_char			sc_mcr;
175 	volatile u_char		sc_rx_stopped;
176 	u_char			sc_rx_unblock;
177 	u_char			sc_tx_stopped;
178 	int			sc_swflags;
179 
180 	enum ucom_state {
181 	    UCOM_DEAD,
182 	    UCOM_ATTACHED,
183 	    UCOM_OPENING,
184 	    UCOM_OPEN
185 	}			sc_state;
186 	bool			sc_closing;	/* software is closing */
187 	bool			sc_dying;	/* hardware is gone */
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 
196 	struct timeval		sc_hup_time;
197 };
198 
199 dev_type_open(ucomopen);
200 dev_type_cancel(ucomcancel);
201 dev_type_close(ucomclose);
202 dev_type_read(ucomread);
203 dev_type_write(ucomwrite);
204 dev_type_ioctl(ucomioctl);
205 dev_type_stop(ucomstop);
206 dev_type_tty(ucomtty);
207 dev_type_poll(ucompoll);
208 
209 const struct cdevsw ucom_cdevsw = {
210 	.d_open = ucomopen,
211 	.d_cancel = ucomcancel,
212 	.d_close = ucomclose,
213 	.d_read = ucomread,
214 	.d_write = ucomwrite,
215 	.d_ioctl = ucomioctl,
216 	.d_stop = ucomstop,
217 	.d_tty = ucomtty,
218 	.d_poll = ucompoll,
219 	.d_mmap = nommap,
220 	.d_kqfilter = ttykqfilter,
221 	.d_discard = nodiscard,
222 	.d_cfdriver = &ucom_cd,
223 	.d_devtounit = ucom_unit,
224 	.d_flag = D_TTY | D_MPSAFE
225 };
226 
227 static void	ucom_cleanup(struct ucom_softc *, int);
228 static int	ucomparam(struct tty *, struct termios *);
229 static int	ucomhwiflow(struct tty *, int);
230 static void	ucomstart(struct tty *);
231 static void	ucom_shutdown(struct ucom_softc *);
232 static void	ucom_dtr(struct ucom_softc *, int);
233 static void	ucom_rts(struct ucom_softc *, int);
234 static void	ucom_break(struct ucom_softc *, int);
235 static void	tiocm_to_ucom(struct ucom_softc *, u_long, int);
236 static int	ucom_to_tiocm(struct ucom_softc *);
237 
238 static void	ucomreadcb(struct usbd_xfer *, void *, usbd_status);
239 static void	ucom_submit_write(struct ucom_softc *, struct ucom_buffer *);
240 static void	ucom_write_status(struct ucom_softc *, struct ucom_buffer *,
241 		    usbd_status);
242 
243 static void	ucomwritecb(struct usbd_xfer *, void *, usbd_status);
244 static void	ucom_read_complete(struct ucom_softc *);
245 static int	ucomsubmitread(struct ucom_softc *, struct ucom_buffer *);
246 static void	ucom_softintr(void *);
247 
248 int ucom_match(device_t, cfdata_t, void *);
249 void ucom_attach(device_t, device_t, void *);
250 int ucom_detach(device_t, int);
251 
252 CFATTACH_DECL_NEW(ucom, sizeof(struct ucom_softc), ucom_match, ucom_attach,
253     ucom_detach, NULL);
254 
255 int
256 ucom_match(device_t parent, cfdata_t match, void *aux)
257 {
258 	return 1;
259 }
260 
261 void
262 ucom_attach(device_t parent, device_t self, void *aux)
263 {
264 	struct ucom_softc *sc = device_private(self);
265 	struct ucom_attach_args *ucaa = aux;
266 
267 	UCOMHIST_FUNC(); UCOMHIST_CALLED();
268 
269 	if (ucaa->ucaa_info != NULL)
270 		aprint_normal(": %s", ucaa->ucaa_info);
271 	aprint_normal("\n");
272 
273 	prop_dictionary_set_int32(device_properties(self), "port",
274 	    ucaa->ucaa_portno);
275 
276 	sc->sc_dev = self;
277 	sc->sc_udev = ucaa->ucaa_device;
278 	sc->sc_iface = ucaa->ucaa_iface;
279 	sc->sc_bulkout_no = ucaa->ucaa_bulkout;
280 	sc->sc_bulkin_no = ucaa->ucaa_bulkin;
281 	sc->sc_ibufsize = ucaa->ucaa_ibufsize;
282 	sc->sc_ibufsizepad = ucaa->ucaa_ibufsizepad;
283 	sc->sc_obufsize = ucaa->ucaa_obufsize;
284 	sc->sc_opkthdrlen = ucaa->ucaa_opkthdrlen;
285 	sc->sc_methods = ucaa->ucaa_methods;
286 	sc->sc_parent = ucaa->ucaa_arg;
287 	sc->sc_portno = ucaa->ucaa_portno;
288 
289 	sc->sc_lsr = 0;
290 	sc->sc_msr = 0;
291 	sc->sc_mcr = 0;
292 	sc->sc_tx_stopped = 0;
293 	sc->sc_swflags = 0;
294 	sc->sc_closing = false;
295 	sc->sc_dying = false;
296 	sc->sc_state = UCOM_DEAD;
297 
298 	sc->sc_si = softint_establish(SOFTINT_USB, ucom_softintr, sc);
299 	mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_SOFTUSB);
300 	cv_init(&sc->sc_statecv, "ucomstate");
301 
302 	rnd_attach_source(&sc->sc_rndsource, device_xname(sc->sc_dev),
303 	    RND_TYPE_TTY, RND_FLAG_DEFAULT);
304 
305 	SIMPLEQ_INIT(&sc->sc_ibuff_empty);
306 	SIMPLEQ_INIT(&sc->sc_ibuff_full);
307 	SIMPLEQ_INIT(&sc->sc_obuff_free);
308 	SIMPLEQ_INIT(&sc->sc_obuff_full);
309 
310 	memset(sc->sc_ibuff, 0, sizeof(sc->sc_ibuff));
311 	memset(sc->sc_obuff, 0, sizeof(sc->sc_obuff));
312 
313 	DPRINTF("open pipes in=%jd out=%jd",
314 	    sc->sc_bulkin_no, sc->sc_bulkout_no, 0, 0);
315 
316 	struct ucom_buffer *ub;
317 	usbd_status err;
318 	int error;
319 
320 	/* Open the bulk pipes */
321 	err = usbd_open_pipe(sc->sc_iface, sc->sc_bulkin_no,
322 	    USBD_EXCLUSIVE_USE, &sc->sc_bulkin_pipe);
323 	if (err) {
324 		DPRINTF("open bulk in error (addr %jd), err=%jd",
325 		    sc->sc_bulkin_no, err, 0, 0);
326 		error = EIO;
327 		goto fail_0;
328 	}
329 	/* Allocate input buffers */
330 	for (ub = &sc->sc_ibuff[0]; ub != &sc->sc_ibuff[UCOM_IN_BUFFS];
331 	    ub++) {
332 		error = usbd_create_xfer(sc->sc_bulkin_pipe,
333 		    sc->sc_ibufsizepad, 0, 0,
334 		    &ub->ub_xfer);
335 		if (error)
336 			goto fail_1;
337 		ub->ub_data = usbd_get_buffer(ub->ub_xfer);
338 	}
339 
340 	err = usbd_open_pipe(sc->sc_iface, sc->sc_bulkout_no,
341 	    USBD_EXCLUSIVE_USE, &sc->sc_bulkout_pipe);
342 	if (err) {
343 		DPRINTF("open bulk out error (addr %jd), err=%jd",
344 		    sc->sc_bulkout_no, err, 0, 0);
345 		error = EIO;
346 		goto fail_1;
347 	}
348 	for (ub = &sc->sc_obuff[0]; ub != &sc->sc_obuff[UCOM_OUT_BUFFS];
349 	    ub++) {
350 		error = usbd_create_xfer(sc->sc_bulkout_pipe,
351 		    sc->sc_obufsize, 0, 0, &ub->ub_xfer);
352 		if (error)
353 			goto fail_2;
354 		ub->ub_data = usbd_get_buffer(ub->ub_xfer);
355 		SIMPLEQ_INSERT_TAIL(&sc->sc_obuff_free, ub, ub_link);
356 	}
357 
358 	struct tty *tp = tty_alloc();
359 	tp->t_oproc = ucomstart;
360 	tp->t_param = ucomparam;
361 	tp->t_hwiflow = ucomhwiflow;
362 	sc->sc_tty = tp;
363 
364 	DPRINTF("tty_attach %#jx", (uintptr_t)tp, 0, 0, 0);
365 	tty_attach(tp);
366 
367 	if (!pmf_device_register(self, NULL, NULL))
368 		aprint_error_dev(self, "couldn't establish power handler\n");
369 
370 	sc->sc_state = UCOM_ATTACHED;
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 	usbd_close_pipe(sc->sc_bulkout_pipe);
380 	sc->sc_bulkout_pipe = NULL;
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 	sc->sc_bulkin_pipe = NULL;
390 
391 fail_0:
392 	aprint_error_dev(self, "attach failed, error=%d\n", error);
393 }
394 
395 int
396 ucom_detach(device_t self, int flags)
397 {
398 	struct ucom_softc *sc = device_private(self);
399 	struct tty *tp = sc->sc_tty;
400 	int maj, mn;
401 	int i;
402 
403 	UCOMHIST_FUNC(); UCOMHIST_CALLED();
404 
405 	DPRINTF("sc=%#jx flags=%jd tp=%#jx", (uintptr_t)sc, flags,
406 	    (uintptr_t)tp, 0);
407 	DPRINTF("... pipe=%jd,%jd", sc->sc_bulkin_no, sc->sc_bulkout_no, 0, 0);
408 
409 	/* Prevent new opens from hanging.  */
410 	mutex_enter(&sc->sc_lock);
411 	sc->sc_dying = true;
412 	mutex_exit(&sc->sc_lock);
413 
414 	pmf_device_deregister(self);
415 
416 	/* tty is now off.  */
417 	if (tp != NULL) {
418 		ttylock(tp);
419 		CLR(tp->t_state, TS_CARR_ON);
420 		CLR(tp->t_cflag, CLOCAL | MDMBUF);
421 		ttyunlock(tp);
422 	}
423 
424 	/* locate the major number */
425 	maj = cdevsw_lookup_major(&ucom_cdevsw);
426 
427 	/* Nuke the vnodes for any open instances. */
428 	mn = device_unit(self);
429 	DPRINTF("maj=%jd mn=%jd", maj, mn, 0, 0);
430 	vdevgone(maj, mn, mn, VCHR);
431 	vdevgone(maj, mn | UCOMDIALOUT_MASK, mn | UCOMDIALOUT_MASK, VCHR);
432 	vdevgone(maj, mn | UCOMCALLUNIT_MASK, mn | UCOMCALLUNIT_MASK, VCHR);
433 
434 	softint_disestablish(sc->sc_si);
435 
436 	/* Detach and free the tty. */
437 	if (tp != NULL) {
438 		tty_detach(tp);
439 		tty_free(tp);
440 		sc->sc_tty = NULL;
441 	}
442 
443 	for (i = 0; i < UCOM_IN_BUFFS; i++) {
444 		if (sc->sc_ibuff[i].ub_xfer != NULL)
445 			usbd_destroy_xfer(sc->sc_ibuff[i].ub_xfer);
446 	}
447 
448 	for (i = 0; i < UCOM_OUT_BUFFS; i++) {
449 		if (sc->sc_obuff[i].ub_xfer != NULL)
450 			usbd_destroy_xfer(sc->sc_obuff[i].ub_xfer);
451 	}
452 
453 	if (sc->sc_bulkin_pipe != NULL) {
454 		usbd_close_pipe(sc->sc_bulkin_pipe);
455 		sc->sc_bulkin_pipe = NULL;
456 	}
457 
458 	if (sc->sc_bulkout_pipe != NULL) {
459 		usbd_close_pipe(sc->sc_bulkout_pipe);
460 		sc->sc_bulkout_pipe = NULL;
461 	}
462 
463 	/* Detach the random source */
464 	rnd_detach_source(&sc->sc_rndsource);
465 
466 	mutex_destroy(&sc->sc_lock);
467 	cv_destroy(&sc->sc_statecv);
468 
469 	return 0;
470 }
471 
472 void
473 ucom_shutdown(struct ucom_softc *sc)
474 {
475 	struct tty *tp = sc->sc_tty;
476 
477 	UCOMHIST_FUNC(); UCOMHIST_CALLED();
478 
479 	/*
480 	 * Hang up if necessary.  Wait a bit, so the other side has time to
481 	 * notice even if we immediately open the port again.
482 	 */
483 	if (ISSET(tp->t_cflag, HUPCL)) {
484 		ucom_dtr(sc, 0);
485 		mutex_enter(&sc->sc_lock);
486 		microuptime(&sc->sc_hup_time);
487 		sc->sc_hup_time.tv_sec++;
488 		mutex_exit(&sc->sc_lock);
489 	}
490 }
491 
492 /*
493  * ucomopen(dev, flag, mode, l)
494  *
495  *	Called when anyone tries to open /dev/ttyU? for an existing
496  *	ucom? instance that has completed attach.  The attach may have
497  *	failed, though, or there may be concurrent detach or close in
498  *	progress, so fail if attach failed (no sc_tty) or detach has
499  *	begun (sc_dying), or wait if there's a concurrent close in
500  *	progress before reopening.
501  */
502 int
503 ucomopen(dev_t dev, int flag, int mode, struct lwp *l)
504 {
505 	const int unit = UCOMUNIT(dev);
506 	struct ucom_softc * const sc = device_lookup_private(&ucom_cd, unit);
507 	int error = 0;
508 
509 	UCOMHIST_FUNC(); UCOMHIST_CALLED();
510 
511 	mutex_enter(&sc->sc_lock);
512 	if (sc->sc_dying) {
513 		DPRINTF("... dying", 0, 0, 0, 0);
514 		mutex_exit(&sc->sc_lock);
515 		return ENXIO;
516 	}
517 
518 	if (!device_is_active(sc->sc_dev)) {
519 		mutex_exit(&sc->sc_lock);
520 		return ENXIO;
521 	}
522 
523 	struct tty *tp = sc->sc_tty;
524 	if (tp == NULL) {
525 		DPRINTF("... not attached", 0, 0, 0, 0);
526 		mutex_exit(&sc->sc_lock);
527 		return ENXIO;
528 	}
529 
530 	DPRINTF("unit=%jd, tp=%#jx", unit, (uintptr_t)tp, 0, 0);
531 
532 	if (kauth_authorize_device_tty(l->l_cred, KAUTH_DEVICE_TTY_OPEN, tp)) {
533 		mutex_exit(&sc->sc_lock);
534 		return EBUSY;
535 	}
536 
537 	/*
538 	 * If the previous use had set DTR on close, wait up to one
539 	 * second for the other side to notice we hung up.  After
540 	 * sleeping, the tty may have been revoked, so restart the
541 	 * whole operation.
542 	 *
543 	 * XXX The wchan is not ttclose but maybe should be.
544 	 */
545 	if (timerisset(&sc->sc_hup_time)) {
546 		struct timeval now, delta;
547 		int ms, ticks;
548 
549 		microuptime(&now);
550 		if (timercmp(&now, &sc->sc_hup_time, <)) {
551 			timersub(&sc->sc_hup_time, &now, &delta);
552 			ms = MIN(INT_MAX - 1000, delta.tv_sec*1000);
553 			ms += howmany(delta.tv_usec, 1000);
554 			ticks = MAX(1, MIN(INT_MAX, mstohz(ms)));
555 			(void)cv_timedwait(&sc->sc_statecv, &sc->sc_lock,
556 			    ticks);
557 			mutex_exit(&sc->sc_lock);
558 			return ERESTART;
559 		}
560 		timerclear(&sc->sc_hup_time);
561 	}
562 
563 	/*
564 	 * Wait while the device is initialized by the
565 	 * first opener or cleaned up by the last closer.
566 	 */
567 	enum ucom_state state = sc->sc_state;
568 	if (state == UCOM_OPENING || sc->sc_closing) {
569 		if (flag & FNONBLOCK)
570 			error = EWOULDBLOCK;
571 		else
572 			error = cv_wait_sig(&sc->sc_statecv, &sc->sc_lock);
573 		mutex_exit(&sc->sc_lock);
574 		return error ? error : ERESTART;
575 	}
576 	KASSERTMSG(state == UCOM_OPEN || state == UCOM_ATTACHED,
577 	    "state is %d", state);
578 
579 	/*
580 	 * If this is the first open, then make sure the pipes are
581 	 * running and perform any initialization needed.
582 	 */
583 	bool firstopen = (state == UCOM_ATTACHED);
584 	if (firstopen) {
585 		KASSERT(!ISSET(tp->t_state, TS_ISOPEN));
586 		KASSERT(tp->t_wopen == 0);
587 
588 		tp->t_dev = dev;
589 		sc->sc_state = UCOM_OPENING;
590 		mutex_exit(&sc->sc_lock);
591 
592 		if (sc->sc_methods->ucom_open != NULL) {
593 			error = sc->sc_methods->ucom_open(sc->sc_parent,
594 			    sc->sc_portno);
595 			if (error)
596 				goto bad;
597 		}
598 
599 		ucom_status_change(sc);
600 
601 		/* Clear PPS capture state on first open. */
602 		mutex_spin_enter(&timecounter_lock);
603 		memset(&sc->sc_pps_state, 0, sizeof(sc->sc_pps_state));
604 		sc->sc_pps_state.ppscap = PPS_CAPTUREASSERT | PPS_CAPTURECLEAR;
605 		pps_init(&sc->sc_pps_state);
606 		mutex_spin_exit(&timecounter_lock);
607 
608 		/*
609 		 * Initialize the termios status to the defaults.  Add in the
610 		 * sticky bits from TIOCSFLAGS.
611 		 */
612 		struct termios t;
613 
614 		t.c_ispeed = 0;
615 		t.c_ospeed = TTYDEF_SPEED;
616 		t.c_cflag = TTYDEF_CFLAG;
617 		if (ISSET(sc->sc_swflags, TIOCFLAG_CLOCAL))
618 			SET(t.c_cflag, CLOCAL);
619 		if (ISSET(sc->sc_swflags, TIOCFLAG_CRTSCTS))
620 			SET(t.c_cflag, CRTSCTS);
621 		if (ISSET(sc->sc_swflags, TIOCFLAG_MDMBUF))
622 			SET(t.c_cflag, MDMBUF);
623 		/* Make sure ucomparam() will do something. */
624 		tp->t_ospeed = 0;
625 		(void) ucomparam(tp, &t);
626 		tp->t_iflag = TTYDEF_IFLAG;
627 		tp->t_oflag = TTYDEF_OFLAG;
628 		tp->t_lflag = TTYDEF_LFLAG;
629 		ttychars(tp);
630 		ttsetwater(tp);
631 
632 		/*
633 		 * Turn on DTR.  We must always do this, even if carrier is not
634 		 * present, because otherwise we'd have to use TIOCSDTR
635 		 * immediately after setting CLOCAL, which applications do not
636 		 * expect.  We always assert DTR while the device is open
637 		 * unless explicitly requested to deassert it.  Ditto RTS.
638 		 */
639 		ucom_dtr(sc, 1);
640 		ucom_rts(sc, 1);
641 
642 		mutex_enter(&sc->sc_lock);
643 		sc->sc_rx_unblock = 0;
644 		sc->sc_rx_stopped = 0;
645 		sc->sc_tx_stopped = 0;
646 
647 		for (size_t i = 0; i < UCOM_IN_BUFFS; i++) {
648 			struct ucom_buffer *ub = &sc->sc_ibuff[i];
649 			error = ucomsubmitread(sc, ub);
650 			if (error) {
651 		    		mutex_exit(&sc->sc_lock);
652 				goto bad;
653 			}
654 		}
655 	}
656 	mutex_exit(&sc->sc_lock);
657 
658 	DPRINTF("unit=%jd, tp=%#jx dialout %jd nonblock %jd", unit,
659 	    (uintptr_t)tp, !!UCOMDIALOUT(dev), !!ISSET(flag, O_NONBLOCK));
660 	error = ttyopen(tp, UCOMDIALOUT(dev), ISSET(flag, O_NONBLOCK));
661 	if (error)
662 		goto bad;
663 
664 	error = (*tp->t_linesw->l_open)(dev, tp);
665 	if (error)
666 		goto bad;
667 
668 	/*
669 	 * Success!  If this was the first open, notify waiters that
670 	 * the tty is open for business.
671 	 */
672 	if (firstopen) {
673 		mutex_enter(&sc->sc_lock);
674 		KASSERT(sc->sc_state == UCOM_OPENING);
675 		sc->sc_state = UCOM_OPEN;
676 		cv_broadcast(&sc->sc_statecv);
677 		mutex_exit(&sc->sc_lock);
678 	}
679 	return 0;
680 
681 bad:
682 	/*
683 	 * Failure!  If this was the first open, hang up, abort pipes,
684 	 * and notify waiters that we're not opening after all.
685 	 */
686 	if (firstopen) {
687 		ucom_cleanup(sc, flag);
688 
689 		mutex_enter(&sc->sc_lock);
690 		KASSERT(sc->sc_state == UCOM_OPENING);
691 		sc->sc_state = UCOM_ATTACHED;
692 		cv_broadcast(&sc->sc_statecv);
693 		mutex_exit(&sc->sc_lock);
694 	}
695 	return error;
696 }
697 
698 /*
699  * ucomcancel(dev, flag, mode, l)
700  *
701  *	Called on revoke or last close.  Must interrupt any pending I/O
702  *	operations and make them fail promptly; once they have all
703  *	finished (except possibly new opens), ucomclose will be called.
704  *	We set sc_closing to block new opens until ucomclose runs.
705  */
706 int
707 ucomcancel(dev_t dev, int flag, int mode, struct lwp *l)
708 {
709 	const int unit = UCOMUNIT(dev);
710 	struct ucom_softc *sc = device_lookup_private(&ucom_cd, unit);
711 
712 	UCOMHIST_FUNC(); UCOMHIST_CALLED();
713 
714 	DPRINTF("unit=%jd", UCOMUNIT(dev), 0, 0, 0);
715 
716 	/*
717 	 * This can run at any time before ucomclose on any device
718 	 * node, even if never attached or if attach failed, so we may
719 	 * not have a softc or a tty.
720 	 */
721 	if (sc == NULL)
722 		return 0;
723 	struct tty *tp = sc->sc_tty;
724 	if (tp == NULL)
725 		return 0;
726 
727 	/*
728 	 * Mark the device closing so opens block until we're done
729 	 * closing.  Wake them up so they start over at the top -- if
730 	 * we're closing because we're detaching, they need to wake up
731 	 * and notice it's time to fail.
732 	 */
733 	mutex_enter(&sc->sc_lock);
734 	sc->sc_closing = true;
735 	cv_broadcast(&sc->sc_statecv);
736 	mutex_exit(&sc->sc_lock);
737 
738 	/*
739 	 * Cancel any pending tty I/O operations, causing them to wake
740 	 * up and fail promptly, and preventing any new ones from
741 	 * starting to wait until we have finished closing.
742 	 */
743 	ttycancel(tp);
744 
745 	return 0;
746 }
747 
748 /*
749  * ucomclose(dev, flag, mode, l)
750  *
751  *	Called after ucomcancel, when all prior operations on the /dev
752  *	node have completed.  Only new opens may be in progress at this
753  *	point, but they will block until sc_closing is set to false.
754  */
755 int
756 ucomclose(dev_t dev, int flag, int mode, struct lwp *l)
757 {
758 	const int unit = UCOMUNIT(dev);
759 	struct ucom_softc *sc = device_lookup_private(&ucom_cd, unit);
760 	int error = 0;
761 
762 	UCOMHIST_FUNC(); UCOMHIST_CALLED();
763 
764 	DPRINTF("unit=%jd", UCOMUNIT(dev), 0, 0, 0);
765 
766 	/*
767 	 * This can run at any time after ucomcancel on any device
768 	 * node, even if never attached or if attach failed, so we may
769 	 * not have a softc or a tty.
770 	 */
771 	if (sc == NULL)
772 		return 0;
773 	struct tty *tp = sc->sc_tty;
774 	if (tp == NULL)
775 		return 0;
776 
777 	/*
778 	 * Close the tty, causing anyone waiting for it to wake, and
779 	 * hang up the phone.
780 	 */
781 	ucom_cleanup(sc, flag);
782 
783 	/*
784 	 * ttyclose should have cleared TS_ISOPEN and interrupted all
785 	 * pending opens, which should have completed by now.
786 	 */
787 	ttylock(tp);
788 	KASSERT(!ISSET(tp->t_state, TS_ISOPEN));
789 	KASSERT(tp->t_wopen == 0);
790 	ttyunlock(tp);
791 
792 	/*
793 	 * Close any device-specific state.
794 	 */
795 	if (sc->sc_methods->ucom_close != NULL) {
796 		sc->sc_methods->ucom_close(sc->sc_parent,
797 		    sc->sc_portno);
798 	}
799 
800 	/*
801 	 * We're now closed.  Can reopen after this point, so resume
802 	 * transfers, mark us no longer closing, and notify anyone
803 	 * waiting in open.  The state may be OPEN or ATTACHED at this
804 	 * point -- OPEN if the device was already open when we closed
805 	 * it, ATTACHED if we interrupted it in the process of opening.
806 	 */
807 	mutex_enter(&sc->sc_lock);
808 	KASSERTMSG(sc->sc_state == UCOM_ATTACHED || sc->sc_state == UCOM_OPEN,
809 	    "%s sc=%p state=%d", device_xname(sc->sc_dev), sc, sc->sc_state);
810 	KASSERT(sc->sc_closing);
811 	sc->sc_state = UCOM_ATTACHED;
812 	sc->sc_closing = false;
813 	cv_broadcast(&sc->sc_statecv);
814 	mutex_exit(&sc->sc_lock);
815 
816 	return error;
817 }
818 
819 int
820 ucomread(dev_t dev, struct uio *uio, int flag)
821 {
822 	const int unit = UCOMUNIT(dev);
823 	struct ucom_softc * const sc = device_lookup_private(&ucom_cd, unit);
824 	struct tty *tp = sc->sc_tty;
825 
826 	UCOMHIST_FUNC(); UCOMHIST_CALLED();
827 
828 	return (*tp->t_linesw->l_read)(tp, uio, flag);
829 }
830 
831 int
832 ucomwrite(dev_t dev, struct uio *uio, int flag)
833 {
834 	const int unit = UCOMUNIT(dev);
835 	struct ucom_softc * const sc = device_lookup_private(&ucom_cd, unit);
836 	struct tty *tp = sc->sc_tty;
837 
838 	UCOMHIST_FUNC(); UCOMHIST_CALLED();
839 
840 	return (*tp->t_linesw->l_write)(tp, uio, flag);
841 }
842 
843 int
844 ucompoll(dev_t dev, int events, struct lwp *l)
845 {
846 	const int unit = UCOMUNIT(dev);
847 	struct ucom_softc * const sc = device_lookup_private(&ucom_cd, unit);
848 	struct tty *tp = sc->sc_tty;
849 
850 	UCOMHIST_FUNC(); UCOMHIST_CALLED();
851 
852 	return (*tp->t_linesw->l_poll)(tp, events, l);
853 }
854 
855 struct tty *
856 ucomtty(dev_t dev)
857 {
858 	const int unit = UCOMUNIT(dev);
859 	struct ucom_softc * const sc = device_lookup_private(&ucom_cd, unit);
860 
861 	return sc->sc_tty;
862 }
863 
864 int
865 ucomioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
866 {
867 	const int unit = UCOMUNIT(dev);
868 	struct ucom_softc * const sc = device_lookup_private(&ucom_cd, unit);
869 	struct tty *tp = sc->sc_tty;
870 	int error;
871 
872 	UCOMHIST_FUNC(); UCOMHIST_CALLED();
873 
874 	DPRINTF("cmd=0x%08jx", cmd, 0, 0, 0);
875 
876 	error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, l);
877 	if (error != EPASSTHROUGH)
878 		return error;
879 
880 	error = ttioctl(tp, cmd, data, flag, l);
881 	if (error != EPASSTHROUGH)
882 		return error;
883 
884 	if (sc->sc_methods->ucom_ioctl != NULL) {
885 		error = sc->sc_methods->ucom_ioctl(sc->sc_parent,
886 		    sc->sc_portno, cmd, data, flag, l->l_proc);
887 		if (error != EPASSTHROUGH)
888 			return error;
889 	}
890 
891 	error = 0;
892 
893 	DPRINTF("our cmd=0x%08jx", cmd, 0, 0, 0);
894 
895 	switch (cmd) {
896 	case TIOCSBRK:
897 		ucom_break(sc, 1);
898 		break;
899 
900 	case TIOCCBRK:
901 		ucom_break(sc, 0);
902 		break;
903 
904 	case TIOCSDTR:
905 		ucom_dtr(sc, 1);
906 		break;
907 
908 	case TIOCCDTR:
909 		ucom_dtr(sc, 0);
910 		break;
911 
912 	case TIOCGFLAGS:
913 		mutex_enter(&sc->sc_lock);
914 		*(int *)data = sc->sc_swflags;
915 		mutex_exit(&sc->sc_lock);
916 		break;
917 
918 	case TIOCSFLAGS:
919 		error = kauth_authorize_device_tty(l->l_cred,
920 		    KAUTH_DEVICE_TTY_PRIVSET, tp);
921 		if (error)
922 			break;
923 		mutex_enter(&sc->sc_lock);
924 		sc->sc_swflags = *(int *)data;
925 		mutex_exit(&sc->sc_lock);
926 		break;
927 
928 	case TIOCMSET:
929 	case TIOCMBIS:
930 	case TIOCMBIC:
931 		tiocm_to_ucom(sc, cmd, *(int *)data);
932 		break;
933 
934 	case TIOCMGET:
935 		*(int *)data = ucom_to_tiocm(sc);
936 		break;
937 
938 	case PPS_IOC_CREATE:
939 	case PPS_IOC_DESTROY:
940 	case PPS_IOC_GETPARAMS:
941 	case PPS_IOC_SETPARAMS:
942 	case PPS_IOC_GETCAP:
943 	case PPS_IOC_FETCH:
944 #ifdef PPS_SYNC
945 	case PPS_IOC_KCBIND:
946 #endif
947 		mutex_spin_enter(&timecounter_lock);
948 		error = pps_ioctl(cmd, data, &sc->sc_pps_state);
949 		mutex_spin_exit(&timecounter_lock);
950 		break;
951 
952 	default:
953 		error = EPASSTHROUGH;
954 		break;
955 	}
956 
957 	return error;
958 }
959 
960 static void
961 tiocm_to_ucom(struct ucom_softc *sc, u_long how, int ttybits)
962 {
963 	u_char combits;
964 
965 	combits = 0;
966 	if (ISSET(ttybits, TIOCM_DTR))
967 		SET(combits, UMCR_DTR);
968 	if (ISSET(ttybits, TIOCM_RTS))
969 		SET(combits, UMCR_RTS);
970 
971 	mutex_enter(&sc->sc_lock);
972 	switch (how) {
973 	case TIOCMBIC:
974 		CLR(sc->sc_mcr, combits);
975 		break;
976 
977 	case TIOCMBIS:
978 		SET(sc->sc_mcr, combits);
979 		break;
980 
981 	case TIOCMSET:
982 		CLR(sc->sc_mcr, UMCR_DTR | UMCR_RTS);
983 		SET(sc->sc_mcr, combits);
984 		break;
985 	}
986 	u_char mcr = sc->sc_mcr;
987 	mutex_exit(&sc->sc_lock);
988 
989 	if (how == TIOCMSET || ISSET(combits, UMCR_DTR))
990 		ucom_dtr(sc, (mcr & UMCR_DTR) != 0);
991 	if (how == TIOCMSET || ISSET(combits, UMCR_RTS))
992 		ucom_rts(sc, (mcr & UMCR_RTS) != 0);
993 }
994 
995 static int
996 ucom_to_tiocm(struct ucom_softc *sc)
997 {
998 	u_char combits;
999 	int ttybits = 0;
1000 
1001 	mutex_enter(&sc->sc_lock);
1002 	combits = sc->sc_mcr;
1003 	if (ISSET(combits, UMCR_DTR))
1004 		SET(ttybits, TIOCM_DTR);
1005 	if (ISSET(combits, UMCR_RTS))
1006 		SET(ttybits, TIOCM_RTS);
1007 
1008 	combits = sc->sc_msr;
1009 	if (ISSET(combits, UMSR_DCD))
1010 		SET(ttybits, TIOCM_CD);
1011 	if (ISSET(combits, UMSR_CTS))
1012 		SET(ttybits, TIOCM_CTS);
1013 	if (ISSET(combits, UMSR_DSR))
1014 		SET(ttybits, TIOCM_DSR);
1015 	if (ISSET(combits, UMSR_RI | UMSR_TERI))
1016 		SET(ttybits, TIOCM_RI);
1017 
1018 #if 0
1019 XXX;
1020 	if (sc->sc_ier != 0)
1021 		SET(ttybits, TIOCM_LE);
1022 #endif
1023 	mutex_exit(&sc->sc_lock);
1024 
1025 	return ttybits;
1026 }
1027 
1028 static void
1029 ucom_break(struct ucom_softc *sc, int onoff)
1030 {
1031 	UCOMHIST_FUNC(); UCOMHIST_CALLED();
1032 
1033 	DPRINTF("onoff=%jd", onoff, 0, 0, 0);
1034 
1035 	if (sc->sc_methods->ucom_set != NULL)
1036 		sc->sc_methods->ucom_set(sc->sc_parent, sc->sc_portno,
1037 		    UCOM_SET_BREAK, onoff);
1038 }
1039 
1040 static void
1041 ucom_dtr(struct ucom_softc *sc, int onoff)
1042 {
1043 	UCOMHIST_FUNC(); UCOMHIST_CALLED();
1044 
1045 	DPRINTF("onoff=%jd", onoff, 0, 0, 0);
1046 
1047 	if (sc->sc_methods->ucom_set != NULL)
1048 		sc->sc_methods->ucom_set(sc->sc_parent, sc->sc_portno,
1049 		    UCOM_SET_DTR, onoff);
1050 }
1051 
1052 static void
1053 ucom_rts(struct ucom_softc *sc, int onoff)
1054 {
1055 	UCOMHIST_FUNC(); UCOMHIST_CALLED();
1056 
1057 	DPRINTF("onoff=%jd", onoff, 0, 0, 0);
1058 
1059 	if (sc->sc_methods->ucom_set != NULL)
1060 		sc->sc_methods->ucom_set(sc->sc_parent, sc->sc_portno,
1061 		    UCOM_SET_RTS, onoff);
1062 }
1063 
1064 void
1065 ucom_status_change(struct ucom_softc *sc)
1066 {
1067 	struct tty *tp = sc->sc_tty;
1068 
1069 	if (sc->sc_methods->ucom_get_status != NULL) {
1070 		u_char msr, lsr;
1071 
1072 		sc->sc_methods->ucom_get_status(sc->sc_parent, sc->sc_portno,
1073 		    &lsr, &msr);
1074 		mutex_enter(&sc->sc_lock);
1075 		u_char old_msr = sc->sc_msr;
1076 
1077 		sc->sc_lsr = lsr;
1078 		sc->sc_msr = msr;
1079 		mutex_exit(&sc->sc_lock);
1080 
1081 		if (ISSET((msr ^ old_msr), UMSR_DCD)) {
1082 			mutex_spin_enter(&timecounter_lock);
1083 			pps_capture(&sc->sc_pps_state);
1084 			pps_event(&sc->sc_pps_state,
1085 			    (sc->sc_msr & UMSR_DCD) ?
1086 			    PPS_CAPTUREASSERT :
1087 			    PPS_CAPTURECLEAR);
1088 			mutex_spin_exit(&timecounter_lock);
1089 
1090 			(*tp->t_linesw->l_modem)(tp, ISSET(msr, UMSR_DCD));
1091 		}
1092 	} else {
1093 		mutex_enter(&sc->sc_lock);
1094 		sc->sc_lsr = 0;
1095 		/* Assume DCD is present, if we have no chance to check it. */
1096 		sc->sc_msr = UMSR_DCD;
1097 		mutex_exit(&sc->sc_lock);
1098 	}
1099 }
1100 
1101 static int
1102 ucomparam(struct tty *tp, struct termios *t)
1103 {
1104 	const int unit = UCOMUNIT(tp->t_dev);
1105 	struct ucom_softc * const sc = device_lookup_private(&ucom_cd, unit);
1106 	int error = 0;
1107 
1108 	/* XXX should take tty lock around touching tp */
1109 
1110 	UCOMHIST_FUNC(); UCOMHIST_CALLED();
1111 
1112 	/* Check requested parameters. */
1113 	if (t->c_ispeed && t->c_ispeed != t->c_ospeed) {
1114 		error = EINVAL;
1115 		goto out;
1116 	}
1117 
1118 	/*
1119 	 * For the console, always force CLOCAL and !HUPCL, so that the port
1120 	 * is always active.
1121 	 */
1122 	if (ISSET(sc->sc_swflags, TIOCFLAG_SOFTCAR)) {
1123 		SET(t->c_cflag, CLOCAL);
1124 		CLR(t->c_cflag, HUPCL);
1125 	}
1126 
1127 	/*
1128 	 * If there were no changes, don't do anything.  This avoids dropping
1129 	 * input and improves performance when all we did was frob things like
1130 	 * VMIN and VTIME.
1131 	 */
1132 	if (tp->t_ospeed == t->c_ospeed &&
1133 	    tp->t_cflag == t->c_cflag) {
1134 		goto out;
1135 	}
1136 
1137 	/* XXX lcr = ISSET(sc->sc_lcr, LCR_SBREAK) | cflag2lcr(t->c_cflag); */
1138 
1139 	/* And copy to tty. */
1140 	tp->t_ispeed = 0;
1141 	tp->t_ospeed = t->c_ospeed;
1142 	tp->t_cflag = t->c_cflag;
1143 
1144 	if (sc->sc_methods->ucom_param != NULL) {
1145 		error = sc->sc_methods->ucom_param(sc->sc_parent, sc->sc_portno,
1146 		    t);
1147 		if (error)
1148 			goto out;
1149 	}
1150 
1151 	/* XXX worry about CHWFLOW */
1152 
1153 	/*
1154 	 * Update the tty layer's idea of the carrier bit, in case we changed
1155 	 * CLOCAL or MDMBUF.  We don't hang up here; we only do that by
1156 	 * explicit request.
1157 	 */
1158 	DPRINTF("l_modem", 0, 0, 0, 0);
1159 	(void) (*tp->t_linesw->l_modem)(tp, ISSET(sc->sc_msr, UMSR_DCD));
1160 
1161 #if 0
1162 XXX what if the hardware is not open
1163 	if (!ISSET(t->c_cflag, CHWFLOW)) {
1164 		if (sc->sc_tx_stopped) {
1165 			sc->sc_tx_stopped = 0;
1166 			ucomstart(tp);
1167 		}
1168 	}
1169 #endif
1170 out:
1171 	return error;
1172 }
1173 
1174 static int
1175 ucomhwiflow(struct tty *tp, int block)
1176 {
1177 	const int unit = UCOMUNIT(tp->t_dev);
1178 	struct ucom_softc * const sc = device_lookup_private(&ucom_cd, unit);
1179 	int old;
1180 
1181 	UCOMHIST_FUNC(); UCOMHIST_CALLED();
1182 
1183 	KASSERT(&sc->sc_lock);
1184 	KASSERT(ttylocked(tp));
1185 
1186 	old = sc->sc_rx_stopped;
1187 	sc->sc_rx_stopped = (u_char)block;
1188 
1189 	if (old && !block) {
1190 		sc->sc_rx_unblock = 1;
1191 		kpreempt_disable();
1192 		softint_schedule(sc->sc_si);
1193 		kpreempt_enable();
1194 	}
1195 
1196 	return 1;
1197 }
1198 
1199 static void
1200 ucomstart(struct tty *tp)
1201 {
1202 	const int unit = UCOMUNIT(tp->t_dev);
1203 	struct ucom_softc * const sc = device_lookup_private(&ucom_cd, unit);
1204 	struct ucom_buffer *ub;
1205 	u_char *data;
1206 	int cnt;
1207 
1208 	UCOMHIST_FUNC(); UCOMHIST_CALLED();
1209 
1210 	if (ISSET(tp->t_state, TS_BUSY | TS_TIMEOUT | TS_TTSTOP))
1211 		goto out;
1212 	if (sc->sc_tx_stopped)
1213 		goto out;
1214 
1215 	if (!ttypull(tp))
1216 		goto out;
1217 
1218 	/* Grab the first contiguous region of buffer space. */
1219 	data = tp->t_outq.c_cf;
1220 	cnt = ndqb(&tp->t_outq, 0);
1221 
1222 	if (cnt == 0)
1223 		goto out;
1224 
1225 	ub = SIMPLEQ_FIRST(&sc->sc_obuff_free);
1226 	if (ub == NULL) {
1227 		SET(tp->t_state, TS_BUSY);
1228 		goto out;
1229 	}
1230 
1231 	SIMPLEQ_REMOVE_HEAD(&sc->sc_obuff_free, ub_link);
1232 
1233 	if (SIMPLEQ_FIRST(&sc->sc_obuff_free) == NULL)
1234 		SET(tp->t_state, TS_BUSY);
1235 
1236 	if (cnt > sc->sc_obufsize)
1237 		cnt = sc->sc_obufsize;
1238 
1239 	if (sc->sc_methods->ucom_write != NULL)
1240 		sc->sc_methods->ucom_write(sc->sc_parent, sc->sc_portno,
1241 		    ub->ub_data, data, &cnt);
1242 	else
1243 		memcpy(ub->ub_data, data, cnt);
1244 
1245 	ub->ub_len = cnt;
1246 	ub->ub_index = 0;
1247 
1248 	SIMPLEQ_INSERT_TAIL(&sc->sc_obuff_full, ub, ub_link);
1249 
1250 	kpreempt_disable();
1251 	softint_schedule(sc->sc_si);
1252 	kpreempt_enable();
1253 
1254  out:
1255 	DPRINTF("... done", 0, 0, 0, 0);
1256 	return;
1257 }
1258 
1259 void
1260 ucomstop(struct tty *tp, int flag)
1261 {
1262 #if 0
1263 	const int unit = UCOMUNIT(tp->t_dev);
1264 	struct ucom_softc * const sc = device_lookup_private(&ucom_cd, unit);
1265 
1266 	mutex_enter(&sc->sc_lock);
1267 	ttylock(tp);
1268 	if (ISSET(tp->t_state, TS_BUSY)) {
1269 		/* obuff_full -> obuff_free? */
1270 		/* sc->sc_tx_stopped = 1; */
1271 		if (!ISSET(tp->t_state, TS_TTSTOP))
1272 			SET(tp->t_state, TS_FLUSH);
1273 	}
1274 	ttyunlock(tp);
1275 	mutex_exit(&sc->sc_lock);
1276 #endif
1277 }
1278 
1279 static void
1280 ucom_write_status(struct ucom_softc *sc, struct ucom_buffer *ub,
1281     usbd_status err)
1282 {
1283 	struct tty *tp = sc->sc_tty;
1284 	uint32_t cc = ub->ub_len;
1285 
1286 	KASSERT(mutex_owned(&sc->sc_lock));
1287 
1288 	switch (err) {
1289 	case USBD_IN_PROGRESS:
1290 		ub->ub_index = ub->ub_len;
1291 		break;
1292 	case USBD_STALLED:
1293 		ub->ub_index = 0;
1294 		kpreempt_disable();
1295 		softint_schedule(sc->sc_si);
1296 		kpreempt_enable();
1297 		break;
1298 	case USBD_NORMAL_COMPLETION:
1299 		usbd_get_xfer_status(ub->ub_xfer, NULL, NULL, &cc, NULL);
1300 		rnd_add_uint32(&sc->sc_rndsource, cc);
1301 		/*FALLTHROUGH*/
1302 	default:
1303 		SIMPLEQ_REMOVE_HEAD(&sc->sc_obuff_full, ub_link);
1304 		SIMPLEQ_INSERT_TAIL(&sc->sc_obuff_free, ub, ub_link);
1305 		cc -= sc->sc_opkthdrlen;
1306 
1307 		ttylock(tp);
1308 		CLR(tp->t_state, TS_BUSY);
1309 		if (ISSET(tp->t_state, TS_FLUSH))
1310 			CLR(tp->t_state, TS_FLUSH);
1311 		else
1312 			ndflush(&tp->t_outq, cc);
1313 		ttyunlock(tp);
1314 
1315 		if (err != USBD_CANCELLED && err != USBD_IOERROR &&
1316 		    !sc->sc_closing) {
1317 			if ((ub = SIMPLEQ_FIRST(&sc->sc_obuff_full)) != NULL)
1318 				ucom_submit_write(sc, ub);
1319 
1320 			ttylock(tp);
1321 			(*tp->t_linesw->l_start)(tp);
1322 			ttyunlock(tp);
1323 		}
1324 		break;
1325 	}
1326 }
1327 
1328 static void
1329 ucom_submit_write(struct ucom_softc *sc, struct ucom_buffer *ub)
1330 {
1331 
1332 	KASSERT(mutex_owned(&sc->sc_lock));
1333 
1334 	usbd_setup_xfer(ub->ub_xfer, sc, ub->ub_data, ub->ub_len,
1335 	    0, USBD_NO_TIMEOUT, ucomwritecb);
1336 
1337 	ucom_write_status(sc, ub, usbd_transfer(ub->ub_xfer));
1338 }
1339 
1340 static void
1341 ucomwritecb(struct usbd_xfer *xfer, void *p, usbd_status status)
1342 {
1343 	struct ucom_softc *sc = (struct ucom_softc *)p;
1344 
1345 	mutex_enter(&sc->sc_lock);
1346 	ucom_write_status(sc, SIMPLEQ_FIRST(&sc->sc_obuff_full), status);
1347 	mutex_exit(&sc->sc_lock);
1348 
1349 }
1350 
1351 static void
1352 ucom_softintr(void *arg)
1353 {
1354 	UCOMHIST_FUNC(); UCOMHIST_CALLED();
1355 
1356 	struct ucom_softc *sc = arg;
1357 	struct tty *tp = sc->sc_tty;
1358 
1359 	mutex_enter(&sc->sc_lock);
1360 	ttylock(tp);
1361 	if (!ISSET(tp->t_state, TS_ISOPEN)) {
1362 		ttyunlock(tp);
1363 		mutex_exit(&sc->sc_lock);
1364 		return;
1365 	}
1366 	ttyunlock(tp);
1367 
1368 	struct ucom_buffer *ub = SIMPLEQ_FIRST(&sc->sc_obuff_full);
1369 
1370 	if (ub != NULL && ub->ub_index == 0)
1371 		ucom_submit_write(sc, ub);
1372 
1373 	if (sc->sc_rx_unblock)
1374 		ucom_read_complete(sc);
1375 
1376 	mutex_exit(&sc->sc_lock);
1377 }
1378 
1379 static void
1380 ucom_read_complete(struct ucom_softc *sc)
1381 {
1382 	int (*rint)(int, struct tty *);
1383 	struct ucom_buffer *ub;
1384 	struct tty *tp;
1385 
1386 	KASSERT(mutex_owned(&sc->sc_lock));
1387 
1388 	tp = sc->sc_tty;
1389 	rint = tp->t_linesw->l_rint;
1390 	ub = SIMPLEQ_FIRST(&sc->sc_ibuff_full);
1391 
1392 	while (ub != NULL && !sc->sc_rx_stopped) {
1393 
1394 		/* XXX ttyinput takes ttylock */
1395 		while (ub->ub_index < ub->ub_len && !sc->sc_rx_stopped) {
1396 			/* Give characters to tty layer. */
1397 			if ((*rint)(ub->ub_data[ub->ub_index], tp) == -1) {
1398 				/* Overflow: drop remainder */
1399 				ub->ub_index = ub->ub_len;
1400 			} else
1401 				ub->ub_index++;
1402 		}
1403 
1404 		if (ub->ub_index == ub->ub_len) {
1405 			SIMPLEQ_REMOVE_HEAD(&sc->sc_ibuff_full, ub_link);
1406 			ucomsubmitread(sc, ub);
1407 			ub = SIMPLEQ_FIRST(&sc->sc_ibuff_full);
1408 		}
1409 	}
1410 
1411 	sc->sc_rx_unblock = (ub != NULL);
1412 }
1413 
1414 static int
1415 ucomsubmitread(struct ucom_softc *sc, struct ucom_buffer *ub)
1416 {
1417 	usbd_status err;
1418 
1419 	KASSERT(mutex_owned(&sc->sc_lock));
1420 
1421 	usbd_setup_xfer(ub->ub_xfer, sc, ub->ub_data, sc->sc_ibufsize,
1422 	    USBD_SHORT_XFER_OK, USBD_NO_TIMEOUT, ucomreadcb);
1423 
1424 	if ((err = usbd_transfer(ub->ub_xfer)) != USBD_IN_PROGRESS) {
1425 		/* XXX: Recover from this, please! */
1426 		printf("%s: err=%s\n", __func__, usbd_errstr(err));
1427 		return EIO;
1428 	}
1429 
1430 	SIMPLEQ_INSERT_TAIL(&sc->sc_ibuff_empty, ub, ub_link);
1431 
1432 	return 0;
1433 }
1434 
1435 static void
1436 ucomreadcb(struct usbd_xfer *xfer, void *p, usbd_status status)
1437 {
1438 	struct ucom_softc *sc = (struct ucom_softc *)p;
1439 	struct ucom_buffer *ub;
1440 	uint32_t cc;
1441 	u_char *cp;
1442 
1443 	UCOMHIST_FUNC(); UCOMHIST_CALLED();
1444 
1445 	mutex_enter(&sc->sc_lock);
1446 
1447 	if (status == USBD_CANCELLED || status == USBD_IOERROR ||
1448 	    sc->sc_closing) {
1449 		DPRINTF("... done (status %jd closing %jd)",
1450 		    status, sc->sc_closing, 0, 0);
1451 		mutex_exit(&sc->sc_lock);
1452 		return;
1453 	}
1454 
1455 	ub = SIMPLEQ_FIRST(&sc->sc_ibuff_empty);
1456 	SIMPLEQ_REMOVE_HEAD(&sc->sc_ibuff_empty, ub_link);
1457 
1458 	if (status != USBD_NORMAL_COMPLETION) {
1459 		if (status == USBD_STALLED) {
1460 			usbd_clear_endpoint_stall_async(sc->sc_bulkin_pipe);
1461 		} else {
1462 			printf("ucomreadcb: wonky status=%s\n",
1463 			    usbd_errstr(status));
1464 		}
1465 
1466 		DPRINTF("... done (status %jd)", status, 0, 0, 0);
1467 		/* re-adds ub to sc_ibuff_empty */
1468 		ucomsubmitread(sc, ub);
1469 		mutex_exit(&sc->sc_lock);
1470 		return;
1471 	}
1472 
1473 	usbd_get_xfer_status(xfer, NULL, (void *)&cp, &cc, NULL);
1474 
1475 #ifdef UCOM_DEBUG
1476 	/* This is triggered by uslsa(4) occasionally. */
1477 	if ((ucomdebug > 0) && (cc == 0)) {
1478 		device_printf(sc->sc_dev, "ucomreadcb: zero length xfer!\n");
1479 	}
1480 #endif
1481 	KDASSERT(cp == ub->ub_data);
1482 
1483 	rnd_add_uint32(&sc->sc_rndsource, cc);
1484 
1485 	if (sc->sc_state != UCOM_OPEN) {
1486 		/* Go around again - we're not quite ready */
1487 		/* re-adds ub to sc_ibuff_empty */
1488 		ucomsubmitread(sc, ub);
1489 		mutex_exit(&sc->sc_lock);
1490 		DPRINTF("... done (not open)", 0, 0, 0, 0);
1491 		return;
1492 	}
1493 
1494 	mutex_exit(&sc->sc_lock);
1495 	if (sc->sc_methods->ucom_read != NULL) {
1496 		sc->sc_methods->ucom_read(sc->sc_parent, sc->sc_portno,
1497 		    &cp, &cc);
1498 		ub->ub_index = (u_int)(cp - ub->ub_data);
1499 	} else
1500 		ub->ub_index = 0;
1501 
1502 	ub->ub_len = cc;
1503 
1504 	mutex_enter(&sc->sc_lock);
1505 	SIMPLEQ_INSERT_TAIL(&sc->sc_ibuff_full, ub, ub_link);
1506 	ucom_read_complete(sc);
1507 	mutex_exit(&sc->sc_lock);
1508 
1509 	DPRINTF("... done", 0, 0, 0, 0);
1510 }
1511 
1512 static void
1513 ucom_cleanup(struct ucom_softc *sc, int flag)
1514 {
1515 	struct tty *tp = sc->sc_tty;
1516 
1517 	UCOMHIST_FUNC(); UCOMHIST_CALLED();
1518 
1519 	DPRINTF("closing pipes", 0, 0, 0, 0);
1520 
1521 	/*
1522 	 * Close the tty and interrupt any pending opens waiting for
1523 	 * carrier so they restart or give up.  This may flush data.
1524 	 */
1525 	(*tp->t_linesw->l_close)(tp, flag);
1526 	ttyclose(tp);
1527 
1528 	/*
1529 	 * Interrupt any pending xfers and cause them to fail promptly.
1530 	 * New xfers will only be submitted under the lock after
1531 	 * sc_closing is cleared.
1532 	 */
1533 	usbd_abort_pipe(sc->sc_bulkin_pipe);
1534 	usbd_abort_pipe(sc->sc_bulkout_pipe);
1535 
1536 	/*
1537 	 * Hang up the phone and start the timer before we can make a
1538 	 * call again, if necessary.
1539 	 */
1540 	ucom_shutdown(sc);
1541 }
1542 
1543 #endif /* NUCOM > 0 */
1544 
1545 int
1546 ucomprint(void *aux, const char *pnp)
1547 {
1548 	struct ucom_attach_args *ucaa = aux;
1549 
1550 	if (pnp)
1551 		aprint_normal("ucom at %s", pnp);
1552 	if (ucaa->ucaa_portno != UCOM_UNK_PORTNO)
1553 		aprint_normal(" portno %d", ucaa->ucaa_portno);
1554 	return UNCONF;
1555 }
1556 
1557 int
1558 ucomsubmatch(device_t parent, cfdata_t cf,
1559 	     const int *ldesc, void *aux)
1560 {
1561 	struct ucom_attach_args *ucaa = aux;
1562 
1563 	if (ucaa->ucaa_portno != UCOM_UNK_PORTNO &&
1564 	    cf->cf_loc[UCOMBUSCF_PORTNO] != UCOMBUSCF_PORTNO_DEFAULT &&
1565 	    cf->cf_loc[UCOMBUSCF_PORTNO] != ucaa->ucaa_portno)
1566 		return 0;
1567 	return config_match(parent, cf, aux);
1568 }
1569