xref: /openbmc/linux/drivers/bluetooth/hci_ldisc.c (revision 0da85d1e)
1 /*
2  *
3  *  Bluetooth HCI UART driver
4  *
5  *  Copyright (C) 2000-2001  Qualcomm Incorporated
6  *  Copyright (C) 2002-2003  Maxim Krasnyansky <maxk@qualcomm.com>
7  *  Copyright (C) 2004-2005  Marcel Holtmann <marcel@holtmann.org>
8  *
9  *
10  *  This program is free software; you can redistribute it and/or modify
11  *  it under the terms of the GNU General Public License as published by
12  *  the Free Software Foundation; either version 2 of the License, or
13  *  (at your option) any later version.
14  *
15  *  This program is distributed in the hope that it will be useful,
16  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
17  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  *  GNU General Public License for more details.
19  *
20  *  You should have received a copy of the GNU General Public License
21  *  along with this program; if not, write to the Free Software
22  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
23  *
24  */
25 
26 #include <linux/module.h>
27 
28 #include <linux/kernel.h>
29 #include <linux/init.h>
30 #include <linux/types.h>
31 #include <linux/fcntl.h>
32 #include <linux/interrupt.h>
33 #include <linux/ptrace.h>
34 #include <linux/poll.h>
35 
36 #include <linux/slab.h>
37 #include <linux/tty.h>
38 #include <linux/errno.h>
39 #include <linux/string.h>
40 #include <linux/signal.h>
41 #include <linux/ioctl.h>
42 #include <linux/skbuff.h>
43 
44 #include <net/bluetooth/bluetooth.h>
45 #include <net/bluetooth/hci_core.h>
46 
47 #include "btintel.h"
48 #include "btbcm.h"
49 #include "hci_uart.h"
50 
51 #define VERSION "2.3"
52 
53 static const struct hci_uart_proto *hup[HCI_UART_MAX_PROTO];
54 
55 int hci_uart_register_proto(const struct hci_uart_proto *p)
56 {
57 	if (p->id >= HCI_UART_MAX_PROTO)
58 		return -EINVAL;
59 
60 	if (hup[p->id])
61 		return -EEXIST;
62 
63 	hup[p->id] = p;
64 
65 	BT_INFO("HCI UART protocol %s registered", p->name);
66 
67 	return 0;
68 }
69 
70 int hci_uart_unregister_proto(const struct hci_uart_proto *p)
71 {
72 	if (p->id >= HCI_UART_MAX_PROTO)
73 		return -EINVAL;
74 
75 	if (!hup[p->id])
76 		return -EINVAL;
77 
78 	hup[p->id] = NULL;
79 
80 	return 0;
81 }
82 
83 static const struct hci_uart_proto *hci_uart_get_proto(unsigned int id)
84 {
85 	if (id >= HCI_UART_MAX_PROTO)
86 		return NULL;
87 
88 	return hup[id];
89 }
90 
91 static inline void hci_uart_tx_complete(struct hci_uart *hu, int pkt_type)
92 {
93 	struct hci_dev *hdev = hu->hdev;
94 
95 	/* Update HCI stat counters */
96 	switch (pkt_type) {
97 	case HCI_COMMAND_PKT:
98 		hdev->stat.cmd_tx++;
99 		break;
100 
101 	case HCI_ACLDATA_PKT:
102 		hdev->stat.acl_tx++;
103 		break;
104 
105 	case HCI_SCODATA_PKT:
106 		hdev->stat.sco_tx++;
107 		break;
108 	}
109 }
110 
111 static inline struct sk_buff *hci_uart_dequeue(struct hci_uart *hu)
112 {
113 	struct sk_buff *skb = hu->tx_skb;
114 
115 	if (!skb)
116 		skb = hu->proto->dequeue(hu);
117 	else
118 		hu->tx_skb = NULL;
119 
120 	return skb;
121 }
122 
123 int hci_uart_tx_wakeup(struct hci_uart *hu)
124 {
125 	if (test_and_set_bit(HCI_UART_SENDING, &hu->tx_state)) {
126 		set_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
127 		return 0;
128 	}
129 
130 	BT_DBG("");
131 
132 	schedule_work(&hu->write_work);
133 
134 	return 0;
135 }
136 
137 static void hci_uart_write_work(struct work_struct *work)
138 {
139 	struct hci_uart *hu = container_of(work, struct hci_uart, write_work);
140 	struct tty_struct *tty = hu->tty;
141 	struct hci_dev *hdev = hu->hdev;
142 	struct sk_buff *skb;
143 
144 	/* REVISIT: should we cope with bad skbs or ->write() returning
145 	 * and error value ?
146 	 */
147 
148 restart:
149 	clear_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
150 
151 	while ((skb = hci_uart_dequeue(hu))) {
152 		int len;
153 
154 		set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
155 		len = tty->ops->write(tty, skb->data, skb->len);
156 		hdev->stat.byte_tx += len;
157 
158 		skb_pull(skb, len);
159 		if (skb->len) {
160 			hu->tx_skb = skb;
161 			break;
162 		}
163 
164 		hci_uart_tx_complete(hu, bt_cb(skb)->pkt_type);
165 		kfree_skb(skb);
166 	}
167 
168 	if (test_bit(HCI_UART_TX_WAKEUP, &hu->tx_state))
169 		goto restart;
170 
171 	clear_bit(HCI_UART_SENDING, &hu->tx_state);
172 }
173 
174 static void hci_uart_init_work(struct work_struct *work)
175 {
176 	struct hci_uart *hu = container_of(work, struct hci_uart, init_ready);
177 	int err;
178 
179 	if (!test_and_clear_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
180 		return;
181 
182 	err = hci_register_dev(hu->hdev);
183 	if (err < 0) {
184 		BT_ERR("Can't register HCI device");
185 		hci_free_dev(hu->hdev);
186 		hu->hdev = NULL;
187 		hu->proto->close(hu);
188 	}
189 
190 	set_bit(HCI_UART_REGISTERED, &hu->flags);
191 }
192 
193 int hci_uart_init_ready(struct hci_uart *hu)
194 {
195 	if (!test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
196 		return -EALREADY;
197 
198 	schedule_work(&hu->init_ready);
199 
200 	return 0;
201 }
202 
203 /* ------- Interface to HCI layer ------ */
204 /* Initialize device */
205 static int hci_uart_open(struct hci_dev *hdev)
206 {
207 	BT_DBG("%s %p", hdev->name, hdev);
208 
209 	/* Nothing to do for UART driver */
210 
211 	set_bit(HCI_RUNNING, &hdev->flags);
212 
213 	return 0;
214 }
215 
216 /* Reset device */
217 static int hci_uart_flush(struct hci_dev *hdev)
218 {
219 	struct hci_uart *hu  = hci_get_drvdata(hdev);
220 	struct tty_struct *tty = hu->tty;
221 
222 	BT_DBG("hdev %p tty %p", hdev, tty);
223 
224 	if (hu->tx_skb) {
225 		kfree_skb(hu->tx_skb); hu->tx_skb = NULL;
226 	}
227 
228 	/* Flush any pending characters in the driver and discipline. */
229 	tty_ldisc_flush(tty);
230 	tty_driver_flush_buffer(tty);
231 
232 	if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
233 		hu->proto->flush(hu);
234 
235 	return 0;
236 }
237 
238 /* Close device */
239 static int hci_uart_close(struct hci_dev *hdev)
240 {
241 	BT_DBG("hdev %p", hdev);
242 
243 	if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags))
244 		return 0;
245 
246 	hci_uart_flush(hdev);
247 	hdev->flush = NULL;
248 	return 0;
249 }
250 
251 /* Send frames from HCI layer */
252 static int hci_uart_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
253 {
254 	struct hci_uart *hu = hci_get_drvdata(hdev);
255 
256 	if (!test_bit(HCI_RUNNING, &hdev->flags))
257 		return -EBUSY;
258 
259 	BT_DBG("%s: type %d len %d", hdev->name, bt_cb(skb)->pkt_type, skb->len);
260 
261 	hu->proto->enqueue(hu, skb);
262 
263 	hci_uart_tx_wakeup(hu);
264 
265 	return 0;
266 }
267 
268 static int hci_uart_setup(struct hci_dev *hdev)
269 {
270 	struct hci_uart *hu = hci_get_drvdata(hdev);
271 	struct hci_rp_read_local_version *ver;
272 	struct sk_buff *skb;
273 
274 	if (hu->proto->setup)
275 		return hu->proto->setup(hu);
276 
277 	if (!test_bit(HCI_UART_VND_DETECT, &hu->hdev_flags))
278 		return 0;
279 
280 	skb = __hci_cmd_sync(hdev, HCI_OP_READ_LOCAL_VERSION, 0, NULL,
281 			     HCI_INIT_TIMEOUT);
282 	if (IS_ERR(skb)) {
283 		BT_ERR("%s: Reading local version information failed (%ld)",
284 		       hdev->name, PTR_ERR(skb));
285 		return 0;
286 	}
287 
288 	if (skb->len != sizeof(*ver)) {
289 		BT_ERR("%s: Event length mismatch for version information",
290 		       hdev->name);
291 		goto done;
292 	}
293 
294 	ver = (struct hci_rp_read_local_version *)skb->data;
295 
296 	switch (le16_to_cpu(ver->manufacturer)) {
297 #ifdef CONFIG_BT_HCIUART_INTEL
298 	case 2:
299 		hdev->set_bdaddr = btintel_set_bdaddr;
300 		btintel_check_bdaddr(hdev);
301 		break;
302 #endif
303 #ifdef CONFIG_BT_HCIUART_BCM
304 	case 15:
305 		hdev->set_bdaddr = btbcm_set_bdaddr;
306 		btbcm_check_bdaddr(hdev);
307 		break;
308 #endif
309 	}
310 
311 done:
312 	kfree_skb(skb);
313 	return 0;
314 }
315 
316 /* ------ LDISC part ------ */
317 /* hci_uart_tty_open
318  *
319  *     Called when line discipline changed to HCI_UART.
320  *
321  * Arguments:
322  *     tty    pointer to tty info structure
323  * Return Value:
324  *     0 if success, otherwise error code
325  */
326 static int hci_uart_tty_open(struct tty_struct *tty)
327 {
328 	struct hci_uart *hu;
329 
330 	BT_DBG("tty %p", tty);
331 
332 	/* Error if the tty has no write op instead of leaving an exploitable
333 	   hole */
334 	if (tty->ops->write == NULL)
335 		return -EOPNOTSUPP;
336 
337 	hu = kzalloc(sizeof(struct hci_uart), GFP_KERNEL);
338 	if (!hu) {
339 		BT_ERR("Can't allocate control structure");
340 		return -ENFILE;
341 	}
342 
343 	tty->disc_data = hu;
344 	hu->tty = tty;
345 	tty->receive_room = 65536;
346 
347 	INIT_WORK(&hu->init_ready, hci_uart_init_work);
348 	INIT_WORK(&hu->write_work, hci_uart_write_work);
349 
350 	spin_lock_init(&hu->rx_lock);
351 
352 	/* Flush any pending characters in the driver and line discipline. */
353 
354 	/* FIXME: why is this needed. Note don't use ldisc_ref here as the
355 	   open path is before the ldisc is referencable */
356 
357 	if (tty->ldisc->ops->flush_buffer)
358 		tty->ldisc->ops->flush_buffer(tty);
359 	tty_driver_flush_buffer(tty);
360 
361 	return 0;
362 }
363 
364 /* hci_uart_tty_close()
365  *
366  *    Called when the line discipline is changed to something
367  *    else, the tty is closed, or the tty detects a hangup.
368  */
369 static void hci_uart_tty_close(struct tty_struct *tty)
370 {
371 	struct hci_uart *hu = tty->disc_data;
372 	struct hci_dev *hdev;
373 
374 	BT_DBG("tty %p", tty);
375 
376 	/* Detach from the tty */
377 	tty->disc_data = NULL;
378 
379 	if (!hu)
380 		return;
381 
382 	hdev = hu->hdev;
383 	if (hdev)
384 		hci_uart_close(hdev);
385 
386 	cancel_work_sync(&hu->write_work);
387 
388 	if (test_and_clear_bit(HCI_UART_PROTO_SET, &hu->flags)) {
389 		if (hdev) {
390 			if (test_bit(HCI_UART_REGISTERED, &hu->flags))
391 				hci_unregister_dev(hdev);
392 			hci_free_dev(hdev);
393 		}
394 		hu->proto->close(hu);
395 	}
396 
397 	kfree(hu);
398 }
399 
400 /* hci_uart_tty_wakeup()
401  *
402  *    Callback for transmit wakeup. Called when low level
403  *    device driver can accept more send data.
404  *
405  * Arguments:        tty    pointer to associated tty instance data
406  * Return Value:    None
407  */
408 static void hci_uart_tty_wakeup(struct tty_struct *tty)
409 {
410 	struct hci_uart *hu = tty->disc_data;
411 
412 	BT_DBG("");
413 
414 	if (!hu)
415 		return;
416 
417 	clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
418 
419 	if (tty != hu->tty)
420 		return;
421 
422 	if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
423 		hci_uart_tx_wakeup(hu);
424 }
425 
426 /* hci_uart_tty_receive()
427  *
428  *     Called by tty low level driver when receive data is
429  *     available.
430  *
431  * Arguments:  tty          pointer to tty isntance data
432  *             data         pointer to received data
433  *             flags        pointer to flags for data
434  *             count        count of received data in bytes
435  *
436  * Return Value:    None
437  */
438 static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data,
439 				 char *flags, int count)
440 {
441 	struct hci_uart *hu = tty->disc_data;
442 
443 	if (!hu || tty != hu->tty)
444 		return;
445 
446 	if (!test_bit(HCI_UART_PROTO_SET, &hu->flags))
447 		return;
448 
449 	spin_lock(&hu->rx_lock);
450 	hu->proto->recv(hu, data, count);
451 
452 	if (hu->hdev)
453 		hu->hdev->stat.byte_rx += count;
454 
455 	spin_unlock(&hu->rx_lock);
456 
457 	tty_unthrottle(tty);
458 }
459 
460 static int hci_uart_register_dev(struct hci_uart *hu)
461 {
462 	struct hci_dev *hdev;
463 
464 	BT_DBG("");
465 
466 	/* Initialize and register HCI device */
467 	hdev = hci_alloc_dev();
468 	if (!hdev) {
469 		BT_ERR("Can't allocate HCI device");
470 		return -ENOMEM;
471 	}
472 
473 	hu->hdev = hdev;
474 
475 	hdev->bus = HCI_UART;
476 	hci_set_drvdata(hdev, hu);
477 
478 	hdev->open  = hci_uart_open;
479 	hdev->close = hci_uart_close;
480 	hdev->flush = hci_uart_flush;
481 	hdev->send  = hci_uart_send_frame;
482 	hdev->setup = hci_uart_setup;
483 	SET_HCIDEV_DEV(hdev, hu->tty->dev);
484 
485 	if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags))
486 		set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
487 
488 	if (test_bit(HCI_UART_EXT_CONFIG, &hu->hdev_flags))
489 		set_bit(HCI_QUIRK_EXTERNAL_CONFIG, &hdev->quirks);
490 
491 	if (!test_bit(HCI_UART_RESET_ON_INIT, &hu->hdev_flags))
492 		set_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks);
493 
494 	if (test_bit(HCI_UART_CREATE_AMP, &hu->hdev_flags))
495 		hdev->dev_type = HCI_AMP;
496 	else
497 		hdev->dev_type = HCI_BREDR;
498 
499 	if (test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
500 		return 0;
501 
502 	if (hci_register_dev(hdev) < 0) {
503 		BT_ERR("Can't register HCI device");
504 		hci_free_dev(hdev);
505 		return -ENODEV;
506 	}
507 
508 	set_bit(HCI_UART_REGISTERED, &hu->flags);
509 
510 	return 0;
511 }
512 
513 static int hci_uart_set_proto(struct hci_uart *hu, int id)
514 {
515 	const struct hci_uart_proto *p;
516 	int err;
517 
518 	p = hci_uart_get_proto(id);
519 	if (!p)
520 		return -EPROTONOSUPPORT;
521 
522 	err = p->open(hu);
523 	if (err)
524 		return err;
525 
526 	hu->proto = p;
527 
528 	err = hci_uart_register_dev(hu);
529 	if (err) {
530 		p->close(hu);
531 		return err;
532 	}
533 
534 	return 0;
535 }
536 
537 static int hci_uart_set_flags(struct hci_uart *hu, unsigned long flags)
538 {
539 	unsigned long valid_flags = BIT(HCI_UART_RAW_DEVICE) |
540 				    BIT(HCI_UART_RESET_ON_INIT) |
541 				    BIT(HCI_UART_CREATE_AMP) |
542 				    BIT(HCI_UART_INIT_PENDING) |
543 				    BIT(HCI_UART_EXT_CONFIG) |
544 				    BIT(HCI_UART_VND_DETECT);
545 
546 	if (flags & ~valid_flags)
547 		return -EINVAL;
548 
549 	hu->hdev_flags = flags;
550 
551 	return 0;
552 }
553 
554 /* hci_uart_tty_ioctl()
555  *
556  *    Process IOCTL system call for the tty device.
557  *
558  * Arguments:
559  *
560  *    tty        pointer to tty instance data
561  *    file       pointer to open file object for device
562  *    cmd        IOCTL command code
563  *    arg        argument for IOCTL call (cmd dependent)
564  *
565  * Return Value:    Command dependent
566  */
567 static int hci_uart_tty_ioctl(struct tty_struct *tty, struct file *file,
568 			      unsigned int cmd, unsigned long arg)
569 {
570 	struct hci_uart *hu = tty->disc_data;
571 	int err = 0;
572 
573 	BT_DBG("");
574 
575 	/* Verify the status of the device */
576 	if (!hu)
577 		return -EBADF;
578 
579 	switch (cmd) {
580 	case HCIUARTSETPROTO:
581 		if (!test_and_set_bit(HCI_UART_PROTO_SET, &hu->flags)) {
582 			err = hci_uart_set_proto(hu, arg);
583 			if (err) {
584 				clear_bit(HCI_UART_PROTO_SET, &hu->flags);
585 				return err;
586 			}
587 		} else
588 			return -EBUSY;
589 		break;
590 
591 	case HCIUARTGETPROTO:
592 		if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
593 			return hu->proto->id;
594 		return -EUNATCH;
595 
596 	case HCIUARTGETDEVICE:
597 		if (test_bit(HCI_UART_REGISTERED, &hu->flags))
598 			return hu->hdev->id;
599 		return -EUNATCH;
600 
601 	case HCIUARTSETFLAGS:
602 		if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
603 			return -EBUSY;
604 		err = hci_uart_set_flags(hu, arg);
605 		if (err)
606 			return err;
607 		break;
608 
609 	case HCIUARTGETFLAGS:
610 		return hu->hdev_flags;
611 
612 	default:
613 		err = n_tty_ioctl_helper(tty, file, cmd, arg);
614 		break;
615 	}
616 
617 	return err;
618 }
619 
620 /*
621  * We don't provide read/write/poll interface for user space.
622  */
623 static ssize_t hci_uart_tty_read(struct tty_struct *tty, struct file *file,
624 				 unsigned char __user *buf, size_t nr)
625 {
626 	return 0;
627 }
628 
629 static ssize_t hci_uart_tty_write(struct tty_struct *tty, struct file *file,
630 				  const unsigned char *data, size_t count)
631 {
632 	return 0;
633 }
634 
635 static unsigned int hci_uart_tty_poll(struct tty_struct *tty,
636 				      struct file *filp, poll_table *wait)
637 {
638 	return 0;
639 }
640 
641 static int __init hci_uart_init(void)
642 {
643 	static struct tty_ldisc_ops hci_uart_ldisc;
644 	int err;
645 
646 	BT_INFO("HCI UART driver ver %s", VERSION);
647 
648 	/* Register the tty discipline */
649 
650 	memset(&hci_uart_ldisc, 0, sizeof (hci_uart_ldisc));
651 	hci_uart_ldisc.magic		= TTY_LDISC_MAGIC;
652 	hci_uart_ldisc.name		= "n_hci";
653 	hci_uart_ldisc.open		= hci_uart_tty_open;
654 	hci_uart_ldisc.close		= hci_uart_tty_close;
655 	hci_uart_ldisc.read		= hci_uart_tty_read;
656 	hci_uart_ldisc.write		= hci_uart_tty_write;
657 	hci_uart_ldisc.ioctl		= hci_uart_tty_ioctl;
658 	hci_uart_ldisc.poll		= hci_uart_tty_poll;
659 	hci_uart_ldisc.receive_buf	= hci_uart_tty_receive;
660 	hci_uart_ldisc.write_wakeup	= hci_uart_tty_wakeup;
661 	hci_uart_ldisc.owner		= THIS_MODULE;
662 
663 	err = tty_register_ldisc(N_HCI, &hci_uart_ldisc);
664 	if (err) {
665 		BT_ERR("HCI line discipline registration failed. (%d)", err);
666 		return err;
667 	}
668 
669 #ifdef CONFIG_BT_HCIUART_H4
670 	h4_init();
671 #endif
672 #ifdef CONFIG_BT_HCIUART_BCSP
673 	bcsp_init();
674 #endif
675 #ifdef CONFIG_BT_HCIUART_LL
676 	ll_init();
677 #endif
678 #ifdef CONFIG_BT_HCIUART_ATH3K
679 	ath_init();
680 #endif
681 #ifdef CONFIG_BT_HCIUART_3WIRE
682 	h5_init();
683 #endif
684 #ifdef CONFIG_BT_HCIUART_BCM
685 	bcm_init();
686 #endif
687 
688 	return 0;
689 }
690 
691 static void __exit hci_uart_exit(void)
692 {
693 	int err;
694 
695 #ifdef CONFIG_BT_HCIUART_H4
696 	h4_deinit();
697 #endif
698 #ifdef CONFIG_BT_HCIUART_BCSP
699 	bcsp_deinit();
700 #endif
701 #ifdef CONFIG_BT_HCIUART_LL
702 	ll_deinit();
703 #endif
704 #ifdef CONFIG_BT_HCIUART_ATH3K
705 	ath_deinit();
706 #endif
707 #ifdef CONFIG_BT_HCIUART_3WIRE
708 	h5_deinit();
709 #endif
710 #ifdef CONFIG_BT_HCIUART_BCM
711 	bcm_deinit();
712 #endif
713 
714 	/* Release tty registration of line discipline */
715 	err = tty_unregister_ldisc(N_HCI);
716 	if (err)
717 		BT_ERR("Can't unregister HCI line discipline (%d)", err);
718 }
719 
720 module_init(hci_uart_init);
721 module_exit(hci_uart_exit);
722 
723 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
724 MODULE_DESCRIPTION("Bluetooth HCI UART driver ver " VERSION);
725 MODULE_VERSION(VERSION);
726 MODULE_LICENSE("GPL");
727 MODULE_ALIAS_LDISC(N_HCI);
728