xref: /netbsd-src/sys/dev/bluetooth/btuart.c (revision 181254a7b1bdde6873432bffef2d2decc4b5c22f)
1 /*	$NetBSD: btuart.c,v 1.29 2019/01/24 09:33:03 knakahara Exp $	*/
2 
3 /*-
4  * Copyright (c) 2006, 2007 KIYOHARA Takashi
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
18  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
19  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
20  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
21  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
22  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
24  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
25  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26  * POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __KERNEL_RCSID(0, "$NetBSD: btuart.c,v 1.29 2019/01/24 09:33:03 knakahara Exp $");
31 
32 #include <sys/param.h>
33 #include <sys/conf.h>
34 #include <sys/device.h>
35 #include <sys/errno.h>
36 #include <sys/fcntl.h>
37 #include <sys/kauth.h>
38 #include <sys/kernel.h>
39 #include <sys/malloc.h>
40 #include <sys/mbuf.h>
41 #include <sys/proc.h>
42 #include <sys/syslimits.h>
43 #include <sys/systm.h>
44 #include <sys/tty.h>
45 
46 #include <sys/bus.h>
47 #include <sys/intr.h>
48 
49 #include <netbt/bluetooth.h>
50 #include <netbt/hci.h>
51 
52 #include "ioconf.h"
53 
54 struct btuart_softc {
55 	device_t	sc_dev;
56 	struct tty *	sc_tp;		/* tty pointer */
57 
58 	bool		sc_enabled;	/* device is enabled */
59 	struct hci_unit *sc_unit;	/* Bluetooth HCI handle */
60 	struct bt_stats	sc_stats;
61 
62 	int		sc_state;	/* receive state */
63 	int		sc_want;	/* how much we want */
64 	struct mbuf *	sc_rxp;		/* incoming packet */
65 
66 	bool		sc_xmit;	/* transmit is active */
67 	struct mbuf *	sc_txp;		/* outgoing packet */
68 
69 	/* transmit queues */
70 	MBUFQ_HEAD()	sc_cmdq;
71 	MBUFQ_HEAD()	sc_aclq;
72 	MBUFQ_HEAD()	sc_scoq;
73 };
74 
75 /* sc_state */
76 #define BTUART_RECV_PKT_TYPE	0	/* packet type */
77 #define BTUART_RECV_ACL_HDR	1	/* acl header */
78 #define BTUART_RECV_SCO_HDR	2	/* sco header */
79 #define BTUART_RECV_EVENT_HDR	3	/* event header */
80 #define BTUART_RECV_ACL_DATA	4	/* acl packet data */
81 #define BTUART_RECV_SCO_DATA	5	/* sco packet data */
82 #define BTUART_RECV_EVENT_DATA	6	/* event packet data */
83 
84 static int btuart_match(device_t, cfdata_t, void *);
85 static void btuart_attach(device_t, device_t, void *);
86 static int btuart_detach(device_t, int);
87 
88 static int btuartopen(dev_t, struct tty *);
89 static int btuartclose(struct tty *, int);
90 static int btuartioctl(struct tty *, u_long, void *, int, struct lwp *);
91 static int btuartinput(int, struct tty *);
92 static int btuartstart(struct tty *);
93 
94 static int btuart_enable(device_t);
95 static void btuart_disable(device_t);
96 static void btuart_output_cmd(device_t, struct mbuf *);
97 static void btuart_output_acl(device_t, struct mbuf *);
98 static void btuart_output_sco(device_t, struct mbuf *);
99 static void btuart_stats(device_t, struct bt_stats *, int);
100 
101 /*
102  * It doesn't need to be exported, as only btuartattach() uses it,
103  * but there's no "official" way to make it static.
104  */
105 CFATTACH_DECL_NEW(btuart, sizeof(struct btuart_softc),
106     btuart_match, btuart_attach, btuart_detach, NULL);
107 
108 static struct linesw btuart_disc = {
109 	.l_name =	"btuart",
110 	.l_open =	btuartopen,
111 	.l_close =	btuartclose,
112 	.l_read =	ttyerrio,
113 	.l_write =	ttyerrio,
114 	.l_ioctl =	btuartioctl,
115 	.l_rint =	btuartinput,
116 	.l_start =	btuartstart,
117 	.l_modem =	ttymodem,
118 	.l_poll =	ttyerrpoll,
119 };
120 
121 static const struct hci_if btuart_hci = {
122 	.enable =	btuart_enable,
123 	.disable =	btuart_disable,
124 	.output_cmd =	btuart_output_cmd,
125 	.output_acl =	btuart_output_acl,
126 	.output_sco =	btuart_output_sco,
127 	.get_stats =	btuart_stats,
128 	.ipl =		IPL_TTY,
129 };
130 
131 /*****************************************************************************
132  *
133  *	autoconf(9) functions
134  */
135 
136 /*
137  * pseudo-device attach routine.
138  */
139 void
140 btuartattach(int num __unused)
141 {
142 	int error;
143 
144 	error = ttyldisc_attach(&btuart_disc);
145 	if (error) {
146 		aprint_error("%s: unable to register line discipline, "
147 		    "error = %d\n", btuart_cd.cd_name, error);
148 
149 		return;
150 	}
151 
152 	error = config_cfattach_attach(btuart_cd.cd_name, &btuart_ca);
153 	if (error) {
154 		aprint_error("%s: unable to register cfattach, error = %d\n",
155 		    btuart_cd.cd_name, error);
156 
157 		config_cfdriver_detach(&btuart_cd);
158 		(void) ttyldisc_detach(&btuart_disc);
159 	}
160 }
161 
162 /*
163  * Autoconf match routine.
164  */
165 static int
166 btuart_match(device_t self __unused, cfdata_t cfdata __unused,
167 	     void *arg __unused)
168 {
169 
170 	/* pseudo-device; always present */
171 	return 1;
172 }
173 
174 /*
175  * Autoconf attach routine.
176  * Called by config_attach_pseudo(9) when we open the line discipline.
177  */
178 static void
179 btuart_attach(device_t parent __unused, device_t self, void *aux __unused)
180 {
181 	struct btuart_softc *sc = device_private(self);
182 
183 	sc->sc_dev = self;
184 
185 	MBUFQ_INIT(&sc->sc_cmdq);
186 	MBUFQ_INIT(&sc->sc_aclq);
187 	MBUFQ_INIT(&sc->sc_scoq);
188 
189 	/* Attach Bluetooth unit */
190 	sc->sc_unit = hci_attach_pcb(&btuart_hci, self, 0);
191 	if (sc->sc_unit == NULL)
192 		aprint_error_dev(self, "HCI attach failed\n");
193 }
194 
195 /*
196  * Autoconf detach routine.
197  * Called when we close the line discipline.
198  */
199 static int
200 btuart_detach(device_t self, int flags __unused)
201 {
202 	struct btuart_softc *sc = device_private(self);
203 
204 	btuart_disable(self);
205 
206 	if (sc->sc_unit) {
207 		hci_detach_pcb(sc->sc_unit);
208 		sc->sc_unit = NULL;
209 	}
210 
211 	return 0;
212 }
213 
214 /*****************************************************************************
215  *
216  *	Line discipline functions.
217  */
218 
219 static int
220 btuartopen(dev_t devno __unused, struct tty *tp)
221 {
222 	struct btuart_softc *sc;
223 	device_t dev;
224 	cfdata_t cfdata;
225 	struct lwp *l = curlwp;		/* XXX */
226 	int error, unit, s;
227 
228 	error = kauth_authorize_device(l->l_cred, KAUTH_DEVICE_BLUETOOTH_BTUART,
229 	    KAUTH_ARG(KAUTH_REQ_DEVICE_BLUETOOTH_BTUART_ADD), NULL, NULL, NULL);
230 	if (error)
231 		return (error);
232 
233 	s = spltty();
234 
235 	if (tp->t_linesw == &btuart_disc) {
236 		sc = tp->t_sc;
237 		if (sc != NULL) {
238 			splx(s);
239 			return EBUSY;
240 		}
241 	}
242 
243 	KASSERT(tp->t_oproc != NULL);
244 
245 	cfdata = malloc(sizeof(struct cfdata), M_DEVBUF, M_WAITOK);
246 	for (unit = 0; unit < btuart_cd.cd_ndevs; unit++)
247 		if (device_lookup(&btuart_cd, unit) == NULL)
248 			break;
249 
250 	cfdata->cf_name = btuart_cd.cd_name;
251 	cfdata->cf_atname = btuart_cd.cd_name;
252 	cfdata->cf_unit = unit;
253 	cfdata->cf_fstate = FSTATE_STAR;
254 
255 	dev = config_attach_pseudo(cfdata);
256 	if (dev == NULL) {
257 		free(cfdata, M_DEVBUF);
258 		splx(s);
259 		return EIO;
260 	}
261 	sc = device_private(dev);
262 
263 	aprint_normal_dev(dev, "major %llu minor %llu\n",
264 	    (unsigned long long)major(tp->t_dev),
265 	    (unsigned long long)minor(tp->t_dev));
266 
267 	sc->sc_tp = tp;
268 	tp->t_sc = sc;
269 
270 	mutex_spin_enter(&tty_lock);
271 	ttyflush(tp, FREAD | FWRITE);
272 	mutex_spin_exit(&tty_lock);
273 
274 	splx(s);
275 
276 	return 0;
277 }
278 
279 static int
280 btuartclose(struct tty *tp, int flag __unused)
281 {
282 	struct btuart_softc *sc = tp->t_sc;
283 	cfdata_t cfdata;
284 	int s;
285 
286 	s = spltty();
287 
288 	mutex_spin_enter(&tty_lock);
289 	ttyflush(tp, FREAD | FWRITE);
290 	mutex_spin_exit(&tty_lock);	/* XXX */
291 
292 	ttyldisc_release(tp->t_linesw);
293 	tp->t_linesw = ttyldisc_default();
294 
295 	if (sc != NULL) {
296 		tp->t_sc = NULL;
297 		if (sc->sc_tp == tp) {
298 			cfdata = device_cfdata(sc->sc_dev);
299 			config_detach(sc->sc_dev, 0);
300 			free(cfdata, M_DEVBUF);
301 		}
302 	}
303 
304 	splx(s);
305 
306 	return 0;
307 }
308 
309 static int
310 btuartioctl(struct tty *tp, u_long cmd, void *data __unused,
311     int flag __unused, struct lwp *l __unused)
312 {
313 	struct btuart_softc *sc = tp->t_sc;
314 	int error;
315 
316 	/*
317 	 * XXX
318 	 * This function can be called without KERNEL_LOCK when caller's
319 	 * struct cdevsw is set D_MPSAFE. Is KERNEL_LOCK required?
320 	 */
321 
322 	if (sc == NULL || tp != sc->sc_tp)
323 		return EPASSTHROUGH;
324 
325 	switch(cmd) {
326 	default:
327 		error = EPASSTHROUGH;
328 		break;
329 	}
330 
331 	return error;
332 }
333 
334 static int
335 btuartinput(int c, struct tty *tp)
336 {
337 	struct btuart_softc *sc = tp->t_sc;
338 	struct mbuf *m = sc->sc_rxp;
339 	int space = 0;
340 
341 	if (!sc->sc_enabled)
342 		return 0;
343 
344 	c &= TTY_CHARMASK;
345 
346 	/* If we already started a packet, find the trailing end of it. */
347 	if (m) {
348 		while (m->m_next)
349 			m = m->m_next;
350 
351 		space = M_TRAILINGSPACE(m);
352 	}
353 
354 	if (space == 0) {
355 		if (m == NULL) {
356 			/* new packet */
357 			MGETHDR(m, M_DONTWAIT, MT_DATA);
358 			if (m == NULL) {
359 				aprint_error_dev(sc->sc_dev, "out of memory\n");
360 				sc->sc_stats.err_rx++;
361 				return 0;	/* (lost sync) */
362 			}
363 
364 			sc->sc_rxp = m;
365 			m->m_pkthdr.len = m->m_len = 0;
366 			space = MHLEN;
367 
368 			sc->sc_state = BTUART_RECV_PKT_TYPE;
369 			sc->sc_want = 1;
370 		} else {
371 			/* extend mbuf */
372 			MGET(m->m_next, M_DONTWAIT, MT_DATA);
373 			if (m->m_next == NULL) {
374 				aprint_error_dev(sc->sc_dev, "out of memory\n");
375 				sc->sc_stats.err_rx++;
376 				return 0;	/* (lost sync) */
377 			}
378 
379 			m = m->m_next;
380 			m->m_len = 0;
381 			space = MLEN;
382 
383 			if (sc->sc_want > MINCLSIZE) {
384 				MCLGET(m, M_DONTWAIT);
385 				if (m->m_flags & M_EXT)
386 					space = MCLBYTES;
387 			}
388 		}
389 	}
390 
391 	mtod(m, uint8_t *)[m->m_len++] = c;
392 	sc->sc_rxp->m_pkthdr.len++;
393 	sc->sc_stats.byte_rx++;
394 
395 	sc->sc_want--;
396 	if (sc->sc_want > 0)
397 		return 0;	/* want more */
398 
399 	switch (sc->sc_state) {
400 	case BTUART_RECV_PKT_TYPE:	/* Got packet type */
401 
402 		switch (c) {
403 		case HCI_ACL_DATA_PKT:
404 			sc->sc_state = BTUART_RECV_ACL_HDR;
405 			sc->sc_want = sizeof(hci_acldata_hdr_t) - 1;
406 			break;
407 
408 		case HCI_SCO_DATA_PKT:
409 			sc->sc_state = BTUART_RECV_SCO_HDR;
410 			sc->sc_want = sizeof(hci_scodata_hdr_t) - 1;
411 			break;
412 
413 		case HCI_EVENT_PKT:
414 			sc->sc_state = BTUART_RECV_EVENT_HDR;
415 			sc->sc_want = sizeof(hci_event_hdr_t) - 1;
416 			break;
417 
418 		default:
419 			aprint_error_dev(sc->sc_dev,
420 			    "Unknown packet type=%#x!\n", c);
421 			sc->sc_stats.err_rx++;
422 			m_freem(sc->sc_rxp);
423 			sc->sc_rxp = NULL;
424 			return 0;	/* (lost sync) */
425 		}
426 
427 		break;
428 
429 	/*
430 	 * we assume (correctly of course :) that the packet headers all fit
431 	 * into a single pkthdr mbuf
432 	 */
433 	case BTUART_RECV_ACL_HDR:	/* Got ACL Header */
434 		sc->sc_state = BTUART_RECV_ACL_DATA;
435 		sc->sc_want = mtod(m, hci_acldata_hdr_t *)->length;
436 		sc->sc_want = le16toh(sc->sc_want);
437 		break;
438 
439 	case BTUART_RECV_SCO_HDR:	/* Got SCO Header */
440 		sc->sc_state = BTUART_RECV_SCO_DATA;
441 		sc->sc_want =  mtod(m, hci_scodata_hdr_t *)->length;
442 		break;
443 
444 	case BTUART_RECV_EVENT_HDR:	/* Got Event Header */
445 		sc->sc_state = BTUART_RECV_EVENT_DATA;
446 		sc->sc_want =  mtod(m, hci_event_hdr_t *)->length;
447 		break;
448 
449 	case BTUART_RECV_ACL_DATA:	/* ACL Packet Complete */
450 		if (!hci_input_acl(sc->sc_unit, sc->sc_rxp))
451 			sc->sc_stats.err_rx++;
452 
453 		sc->sc_stats.acl_rx++;
454 		sc->sc_rxp = m = NULL;
455 		break;
456 
457 	case BTUART_RECV_SCO_DATA:	/* SCO Packet Complete */
458 		if (!hci_input_sco(sc->sc_unit, sc->sc_rxp))
459 			sc->sc_stats.err_rx++;
460 
461 		sc->sc_stats.sco_rx++;
462 		sc->sc_rxp = m = NULL;
463 		break;
464 
465 	case BTUART_RECV_EVENT_DATA:	/* Event Packet Complete */
466 		if (!hci_input_event(sc->sc_unit, sc->sc_rxp))
467 			sc->sc_stats.err_rx++;
468 
469 		sc->sc_stats.evt_rx++;
470 		sc->sc_rxp = m = NULL;
471 		break;
472 
473 	default:
474 		panic("%s: invalid state %d!\n",
475 		    device_xname(sc->sc_dev), sc->sc_state);
476 	}
477 
478 	return 0;
479 }
480 
481 static int
482 btuartstart(struct tty *tp)
483 {
484 	struct btuart_softc *sc = tp->t_sc;
485 	struct mbuf *m;
486 	int count, rlen;
487 	uint8_t *rptr;
488 
489 	if (!sc->sc_enabled)
490 		return 0;
491 
492 	m = sc->sc_txp;
493 	if (m == NULL) {
494 		if (MBUFQ_FIRST(&sc->sc_cmdq)) {
495 			MBUFQ_DEQUEUE(&sc->sc_cmdq, m);
496 			sc->sc_stats.cmd_tx++;
497 		} else if (MBUFQ_FIRST(&sc->sc_scoq)) {
498 			MBUFQ_DEQUEUE(&sc->sc_scoq, m);
499 			sc->sc_stats.sco_tx++;
500 		} else if (MBUFQ_FIRST(&sc->sc_aclq)) {
501 			MBUFQ_DEQUEUE(&sc->sc_aclq, m);
502 			sc->sc_stats.acl_tx++;
503 		} else {
504 			sc->sc_xmit = false;
505 			return 0; /* no more to send */
506 		}
507 
508 		sc->sc_txp = m;
509 		sc->sc_xmit = true;
510 	}
511 
512 	count = 0;
513 	rlen = 0;
514 	rptr = mtod(m, uint8_t *);
515 
516 	for(;;) {
517 		if (rlen >= m->m_len) {
518 			m = m->m_next;
519 			if (m == NULL) {
520 				m = sc->sc_txp;
521 				sc->sc_txp = NULL;
522 
523 				if (M_GETCTX(m, void *) == NULL)
524 					m_freem(m);
525 				else if (!hci_complete_sco(sc->sc_unit, m))
526 					sc->sc_stats.err_tx++;
527 
528 				break;
529 			}
530 
531 			rlen = 0;
532 			rptr = mtod(m, uint8_t *);
533 			continue;
534 		}
535 
536 		if (putc(*rptr++, &tp->t_outq) < 0) {
537 			m_adj(m, rlen);
538 			break;
539 		}
540 		rlen++;
541 		count++;
542 	}
543 
544 	sc->sc_stats.byte_tx += count;
545 
546 	if (tp->t_outq.c_cc != 0)
547 		(*tp->t_oproc)(tp);
548 
549 	return 0;
550 }
551 
552 /*****************************************************************************
553  *
554  *	bluetooth(9) functions
555  */
556 
557 static int
558 btuart_enable(device_t self)
559 {
560 	struct btuart_softc *sc = device_private(self);
561 	int s;
562 
563 	if (sc->sc_enabled)
564 		return 0;
565 
566 	s = spltty();
567 
568 	sc->sc_enabled = true;
569 	sc->sc_xmit = false;
570 
571 	splx(s);
572 
573 	return 0;
574 }
575 
576 static void
577 btuart_disable(device_t self)
578 {
579 	struct btuart_softc *sc = device_private(self);
580 	int s;
581 
582 	if (!sc->sc_enabled)
583 		return;
584 
585 	s = spltty();
586 
587 	if (sc->sc_rxp) {
588 		m_freem(sc->sc_rxp);
589 		sc->sc_rxp = NULL;
590 	}
591 
592 	if (sc->sc_txp) {
593 		m_freem(sc->sc_txp);
594 		sc->sc_txp = NULL;
595 	}
596 
597 	MBUFQ_DRAIN(&sc->sc_cmdq);
598 	MBUFQ_DRAIN(&sc->sc_aclq);
599 	MBUFQ_DRAIN(&sc->sc_scoq);
600 
601 	sc->sc_enabled = false;
602 
603 	splx(s);
604 }
605 
606 static void
607 btuart_output_cmd(device_t self, struct mbuf *m)
608 {
609 	struct btuart_softc *sc = device_private(self);
610 	int s;
611 
612 	KASSERT(sc->sc_enabled);
613 
614 	M_SETCTX(m, NULL);
615 
616 	s = spltty();
617 	MBUFQ_ENQUEUE(&sc->sc_cmdq, m);
618 	if (!sc->sc_xmit)
619 		btuartstart(sc->sc_tp);
620 
621 	splx(s);
622 }
623 
624 static void
625 btuart_output_acl(device_t self, struct mbuf *m)
626 {
627 	struct btuart_softc *sc = device_private(self);
628 	int s;
629 
630 	KASSERT(sc->sc_enabled);
631 
632 	M_SETCTX(m, NULL);
633 
634 	s = spltty();
635 	MBUFQ_ENQUEUE(&sc->sc_aclq, m);
636 	if (!sc->sc_xmit)
637 		btuartstart(sc->sc_tp);
638 
639 	splx(s);
640 }
641 
642 static void
643 btuart_output_sco(device_t self, struct mbuf *m)
644 {
645 	struct btuart_softc *sc = device_private(self);
646 	int s;
647 
648 	KASSERT(sc->sc_enabled);
649 
650 	s = spltty();
651 	MBUFQ_ENQUEUE(&sc->sc_scoq, m);
652 	if (!sc->sc_xmit)
653 		btuartstart(sc->sc_tp);
654 
655 	splx(s);
656 }
657 
658 static void
659 btuart_stats(device_t self, struct bt_stats *dest, int flush)
660 {
661 	struct btuart_softc *sc = device_private(self);
662 	int s;
663 
664 	s = spltty();
665 
666 	memcpy(dest, &sc->sc_stats, sizeof(struct bt_stats));
667 
668 	if (flush)
669 		memset(&sc->sc_stats, 0, sizeof(struct bt_stats));
670 
671 	splx(s);
672 }
673