summaryrefslogtreecommitdiffstats
path: root/drivers/bluetooth/hci_ldisc.c
blob: 0d5a05a7c1fd1d46a8b77d71b94f97a9df4190b3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
/*
 *
 *  Bluetooth HCI UART driver
 *
 *  Copyright (C) 2000-2001  Qualcomm Incorporated
 *  Copyright (C) 2002-2003  Maxim Krasnyansky <maxk@qualcomm.com>
 *  Copyright (C) 2004-2005  Marcel Holtmann <marcel@holtmann.org>
 *
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#include <linux/module.h>

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/interrupt.h>
#include <linux/ptrace.h>
#include <linux/poll.h>

#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/signal.h>
#include <linux/ioctl.h>
#include <linux/skbuff.h>
#include <linux/firmware.h>

#include <net/bluetooth/bluetooth.h>
#include <net/bluetooth/hci_core.h>

#include "btintel.h"
#include "btbcm.h"
#include "hci_uart.h"

#define VERSION "2.3"

static const struct hci_uart_proto *hup[HCI_UART_MAX_PROTO];

int hci_uart_register_proto(const struct hci_uart_proto *p)
{
	if (p->id >= HCI_UART_MAX_PROTO)
		return -EINVAL;

	if (hup[p->id])
		return -EEXIST;

	hup[p->id] = p;

	BT_INFO("HCI UART protocol %s registered", p->name);

	return 0;
}

int hci_uart_unregister_proto(const struct hci_uart_proto *p)
{
	if (p->id >= HCI_UART_MAX_PROTO)
		return -EINVAL;

	if (!hup[p->id])
		return -EINVAL;

	hup[p->id] = NULL;

	return 0;
}

static const struct hci_uart_proto *hci_uart_get_proto(unsigned int id)
{
	if (id >= HCI_UART_MAX_PROTO)
		return NULL;

	return hup[id];
}

static inline void hci_uart_tx_complete(struct hci_uart *hu, int pkt_type)
{
	struct hci_dev *hdev = hu->hdev;

	/* Update HCI stat counters */
	switch (pkt_type) {
	case HCI_COMMAND_PKT:
		hdev->stat.cmd_tx++;
		break;

	case HCI_ACLDATA_PKT:
		hdev->stat.acl_tx++;
		break;

	case HCI_SCODATA_PKT:
		hdev->stat.sco_tx++;
		break;
	}
}

static inline struct sk_buff *hci_uart_dequeue(struct hci_uart *hu)
{
	struct sk_buff *skb = hu->tx_skb;

	if (!skb)
		skb = hu->proto->dequeue(hu);
	else
		hu->tx_skb = NULL;

	return skb;
}

int hci_uart_tx_wakeup(struct hci_uart *hu)
{
	if (test_and_set_bit(HCI_UART_SENDING, &hu->tx_state)) {
		set_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
		return 0;
	}

	BT_DBG("");

	schedule_work(&hu->write_work);

	return 0;
}

static void hci_uart_write_work(struct work_struct *work)
{
	struct hci_uart *hu = container_of(work, struct hci_uart, write_work);
	struct tty_struct *tty = hu->tty;
	struct hci_dev *hdev = hu->hdev;
	struct sk_buff *skb;

	/* REVISIT: should we cope with bad skbs or ->write() returning
	 * and error value ?
	 */

restart:
	clear_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);

	while ((skb = hci_uart_dequeue(hu))) {
		int len;

		set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
		len = tty->ops->write(tty, skb->data, skb->len);
		hdev->stat.byte_tx += len;

		skb_pull(skb, len);
		if (skb->len) {
			hu->tx_skb = skb;
			break;
		}

		hci_uart_tx_complete(hu, bt_cb(skb)->pkt_type);
		kfree_skb(skb);
	}

	if (test_bit(HCI_UART_TX_WAKEUP, &hu->tx_state))
		goto restart;

	clear_bit(HCI_UART_SENDING, &hu->tx_state);
}

static void hci_uart_init_work(struct work_struct *work)
{
	struct hci_uart *hu = container_of(work, struct hci_uart, init_ready);
	int err;

	if (!test_and_clear_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
		return;

	err = hci_register_dev(hu->hdev);
	if (err < 0) {
		BT_ERR("Can't register HCI device");
		hci_free_dev(hu->hdev);
		hu->hdev = NULL;
		hu->proto->close(hu);
	}

	set_bit(HCI_UART_REGISTERED, &hu->flags);
}

int hci_uart_init_ready(struct hci_uart *hu)
{
	if (!test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
		return -EALREADY;

	schedule_work(&hu->init_ready);

	return 0;
}

/* ------- Interface to HCI layer ------ */
/* Initialize device */
static int hci_uart_open(struct hci_dev *hdev)
{
	BT_DBG("%s %p", hdev->name, hdev);

	/* Nothing to do for UART driver */

	set_bit(HCI_RUNNING, &hdev->flags);

	return 0;
}

/* Reset device */
static int hci_uart_flush(struct hci_dev *hdev)
{
	struct hci_uart *hu  = hci_get_drvdata(hdev);
	struct tty_struct *tty = hu->tty;

	BT_DBG("hdev %p tty %p", hdev, tty);

	if (hu->tx_skb) {
		kfree_skb(hu->tx_skb); hu->tx_skb = NULL;
	}

	/* Flush any pending characters in the driver and discipline. */
	tty_ldisc_flush(tty);
	tty_driver_flush_buffer(tty);

	if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
		hu->proto->flush(hu);

	return 0;
}

/* Close device */
static int hci_uart_close(struct hci_dev *hdev)
{
	BT_DBG("hdev %p", hdev);

	if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags))
		return 0;

	hci_uart_flush(hdev);
	hdev->flush = NULL;
	return 0;
}

/* Send frames from HCI layer */
static int hci_uart_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
{
	struct hci_uart *hu = hci_get_drvdata(hdev);

	if (!test_bit(HCI_RUNNING, &hdev->flags))
		return -EBUSY;

	BT_DBG("%s: type %d len %d", hdev->name, bt_cb(skb)->pkt_type, skb->len);

	hu->proto->enqueue(hu, skb);

	hci_uart_tx_wakeup(hu);

	return 0;
}

/* Flow control or un-flow control the device */
void hci_uart_set_flow_control(struct hci_uart *hu, bool enable)
{
	struct tty_struct *tty = hu->tty;
	struct ktermios ktermios;
	int status;
	unsigned int set = 0;
	unsigned int clear = 0;

	if (enable) {
		/* Disable hardware flow control */
		ktermios = tty->termios;
		ktermios.c_cflag &= ~CRTSCTS;
		status = tty_set_termios(tty, &ktermios);
		BT_DBG("Disabling hardware flow control: %s",
		       status ? "failed" : "success");

		/* Clear RTS to prevent the device from sending */
		/* Most UARTs need OUT2 to enable interrupts */
		status = tty->driver->ops->tiocmget(tty);
		BT_DBG("Current tiocm 0x%x", status);

		set &= ~(TIOCM_OUT2 | TIOCM_RTS);
		clear = ~set;
		set &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
		       TIOCM_OUT2 | TIOCM_LOOP;
		clear &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
			 TIOCM_OUT2 | TIOCM_LOOP;
		status = tty->driver->ops->tiocmset(tty, set, clear);
		BT_DBG("Clearing RTS: %s", status ? "failed" : "success");
	} else {
		/* Set RTS to allow the device to send again */
		status = tty->driver->ops->tiocmget(tty);
		BT_DBG("Current tiocm 0x%x", status);

		set |= (TIOCM_OUT2 | TIOCM_RTS);
		clear = ~set;
		set &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
		       TIOCM_OUT2 | TIOCM_LOOP;
		clear &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
			 TIOCM_OUT2 | TIOCM_LOOP;
		status = tty->driver->ops->tiocmset(tty, set, clear);
		BT_DBG("Setting RTS: %s", status ? "failed" : "success");

		/* Re-enable hardware flow control */
		ktermios = tty->termios;
		ktermios.c_cflag |= CRTSCTS;
		status = tty_set_termios(tty, &ktermios);
		BT_DBG("Enabling hardware flow control: %s",
		       status ? "failed" : "success");
	}
}

void hci_uart_set_speeds(struct hci_uart *hu, unsigned int init_speed,
			 unsigned int oper_speed)
{
	hu->init_speed = init_speed;
	hu->oper_speed = oper_speed;
}

void hci_uart_init_tty(struct hci_uart *hu)
{
	struct tty_struct *tty = hu->tty;
	struct ktermios ktermios;

	/* Bring the UART into a known 8 bits no parity hw fc state */
	ktermios = tty->termios;
	ktermios.c_iflag &= ~(IGNBRK | BRKINT | PARMRK | ISTRIP |
			      INLCR | IGNCR | ICRNL | IXON);
	ktermios.c_oflag &= ~OPOST;
	ktermios.c_lflag &= ~(ECHO | ECHONL | ICANON | ISIG | IEXTEN);
	ktermios.c_cflag &= ~(CSIZE | PARENB);
	ktermios.c_cflag |= CS8;
	ktermios.c_cflag |= CRTSCTS;

	/* tty_set_termios() return not checked as it is always 0 */
	tty_set_termios(tty, &ktermios);
}

void hci_uart_set_baudrate(struct hci_uart *hu, unsigned int speed)
{
	struct tty_struct *tty = hu->tty;
	struct ktermios ktermios;

	ktermios = tty->termios;
	ktermios.c_cflag &= ~CBAUD;
	tty_termios_encode_baud_rate(&ktermios, speed, speed);

	/* tty_set_termios() return not checked as it is always 0 */
	tty_set_termios(tty, &ktermios);

	BT_DBG("%s: New tty speeds: %d/%d", hu->hdev->name,
	       tty->termios.c_ispeed, tty->termios.c_ospeed);
}

static int hci_uart_setup(struct hci_dev *hdev)
{
	struct hci_uart *hu = hci_get_drvdata(hdev);
	struct hci_rp_read_local_version *ver;
	struct sk_buff *skb;
	unsigned int speed;
	int err;

	/* Init speed if any */
	if (hu->init_speed)
		speed = hu->init_speed;
	else if (hu->proto->init_speed)
		speed = hu->proto->init_speed;
	else
		speed = 0;

	if (speed)
		hci_uart_set_baudrate(hu, speed);

	/* Operational speed if any */
	if (hu->oper_speed)
		speed = hu->oper_speed;
	else if (hu->proto->oper_speed)
		speed = hu->proto->oper_speed;
	else
		speed = 0;

	if (hu->proto->set_baudrate && speed) {
		err = hu->proto->set_baudrate(hu, speed);
		if (!err)
			hci_uart_set_baudrate(hu, speed);
	}

	if (hu->proto->setup)
		return hu->proto->setup(hu);

	if (!test_bit(HCI_UART_VND_DETECT, &hu->hdev_flags))
		return 0;

	skb = __hci_cmd_sync(hdev, HCI_OP_READ_LOCAL_VERSION, 0, NULL,
			     HCI_INIT_TIMEOUT);
	if (IS_ERR(skb)) {
		BT_ERR("%s: Reading local version information failed (%ld)",
		       hdev->name, PTR_ERR(skb));
		return 0;
	}

	if (skb->len != sizeof(*ver)) {
		BT_ERR("%s: Event length mismatch for version information",
		       hdev->name);
		goto done;
	}

	ver = (struct hci_rp_read_local_version *)skb->data;

	switch (le16_to_cpu(ver->manufacturer)) {
#ifdef CONFIG_BT_HCIUART_INTEL
	case 2:
		hdev->set_bdaddr = btintel_set_bdaddr;
		btintel_check_bdaddr(hdev);
		break;
#endif
#ifdef CONFIG_BT_HCIUART_BCM
	case 15:
		hdev->set_bdaddr = btbcm_set_bdaddr;
		btbcm_check_bdaddr(hdev);
		break;
#endif
	}

done:
	kfree_skb(skb);
	return 0;
}

/* ------ LDISC part ------ */
/* hci_uart_tty_open
 *
 *     Called when line discipline changed to HCI_UART.
 *
 * Arguments:
 *     tty    pointer to tty info structure
 * Return Value:
 *     0 if success, otherwise error code
 */
static int hci_uart_tty_open(struct tty_struct *tty)
{
	struct hci_uart *hu;

	BT_DBG("tty %p", tty);

	/* Error if the tty has no write op instead of leaving an exploitable
	   hole */
	if (tty->ops->write == NULL)
		return -EOPNOTSUPP;

	hu = kzalloc(sizeof(struct hci_uart), GFP_KERNEL);
	if (!hu) {
		BT_ERR("Can't allocate control structure");
		return -ENFILE;
	}

	tty->disc_data = hu;
	hu->tty = tty;
	tty->receive_room = 65536;

	INIT_WORK(&hu->init_ready, hci_uart_init_work);
	INIT_WORK(&hu->write_work, hci_uart_write_work);

	spin_lock_init(&hu->rx_lock);

	/* Flush any pending characters in the driver and line discipline. */

	/* FIXME: why is this needed. Note don't use ldisc_ref here as the
	   open path is before the ldisc is referencable */

	if (tty->ldisc->ops->flush_buffer)
		tty->ldisc->ops->flush_buffer(tty);
	tty_driver_flush_buffer(tty);

	return 0;
}

/* hci_uart_tty_close()
 *
 *    Called when the line discipline is changed to something
 *    else, the tty is closed, or the tty detects a hangup.
 */
static void hci_uart_tty_close(struct tty_struct *tty)
{
	struct hci_uart *hu = tty->disc_data;
	struct hci_dev *hdev;

	BT_DBG("tty %p", tty);

	/* Detach from the tty */
	tty->disc_data = NULL;

	if (!hu)
		return;

	hdev = hu->hdev;
	if (hdev)
		hci_uart_close(hdev);

	cancel_work_sync(&hu->write_work);

	if (test_and_clear_bit(HCI_UART_PROTO_SET, &hu->flags)) {
		if (hdev) {
			if (test_bit(HCI_UART_REGISTERED, &hu->flags))
				hci_unregister_dev(hdev);
			hci_free_dev(hdev);
		}
		hu->proto->close(hu);
	}

	kfree(hu);
}

/* hci_uart_tty_wakeup()
 *
 *    Callback for transmit wakeup. Called when low level
 *    device driver can accept more send data.
 *
 * Arguments:        tty    pointer to associated tty instance data
 * Return Value:    None
 */
static void hci_uart_tty_wakeup(struct tty_struct *tty)
{
	struct hci_uart *hu = tty->disc_data;

	BT_DBG("");

	if (!hu)
		return;

	clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);

	if (tty != hu->tty)
		return;

	if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
		hci_uart_tx_wakeup(hu);
}

/* hci_uart_tty_receive()
 *
 *     Called by tty low level driver when receive data is
 *     available.
 *
 * Arguments:  tty          pointer to tty isntance data
 *             data         pointer to received data
 *             flags        pointer to flags for data
 *             count        count of received data in bytes
 *
 * Return Value:    None
 */
static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data,
				 char *flags, int count)
{
	struct hci_uart *hu = tty->disc_data;

	if (!hu || tty != hu->tty)
		return;

	if (!test_bit(HCI_UART_PROTO_SET, &hu->flags))
		return;

	spin_lock(&hu->rx_lock);
	hu->proto->recv(hu, data, count);

	if (hu->hdev)
		hu->hdev->stat.byte_rx += count;

	spin_unlock(&hu->rx_lock);

	tty_unthrottle(tty);
}

static int hci_uart_register_dev(struct hci_uart *hu)
{
	struct hci_dev *hdev;

	BT_DBG("");

	/* Initialize and register HCI device */
	hdev = hci_alloc_dev();
	if (!hdev) {
		BT_ERR("Can't allocate HCI device");
		return -ENOMEM;
	}

	hu->hdev = hdev;

	hdev->bus = HCI_UART;
	hci_set_drvdata(hdev, hu);

	hdev->open  = hci_uart_open;
	hdev->close = hci_uart_close;
	hdev->flush = hci_uart_flush;
	hdev->send  = hci_uart_send_frame;
	hdev->setup = hci_uart_setup;
	SET_HCIDEV_DEV(hdev, hu->tty->dev);

	if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags))
		set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);

	if (test_bit(HCI_UART_EXT_CONFIG, &hu->hdev_flags))
		set_bit(HCI_QUIRK_EXTERNAL_CONFIG, &hdev->quirks);

	if (!test_bit(HCI_UART_RESET_ON_INIT, &hu->hdev_flags))
		set_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks);

	if (test_bit(HCI_UART_CREATE_AMP, &hu->hdev_flags))
		hdev->dev_type = HCI_AMP;
	else
		hdev->dev_type = HCI_BREDR;

	if (test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
		return 0;

	if (hci_register_dev(hdev) < 0) {
		BT_ERR("Can't register HCI device");
		hci_free_dev(hdev);
		return -ENODEV;
	}

	set_bit(HCI_UART_REGISTERED, &hu->flags);

	return 0;
}

static int hci_uart_set_proto(struct hci_uart *hu, int id)
{
	const struct hci_uart_proto *p;
	int err;

	p = hci_uart_get_proto(id);
	if (!p)
		return -EPROTONOSUPPORT;

	err = p->open(hu);
	if (err)
		return err;

	hu->proto = p;

	err = hci_uart_register_dev(hu);
	if (err) {
		p->close(hu);
		return err;
	}

	return 0;
}

static int hci_uart_set_flags(struct hci_uart *hu, unsigned long flags)
{
	unsigned long valid_flags = BIT(HCI_UART_RAW_DEVICE) |
				    BIT(HCI_UART_RESET_ON_INIT) |
				    BIT(HCI_UART_CREATE_AMP) |
				    BIT(HCI_UART_INIT_PENDING) |
				    BIT(HCI_UART_EXT_CONFIG) |
				    BIT(HCI_UART_VND_DETECT);

	if (flags & ~valid_flags)
		return -EINVAL;

	hu->hdev_flags = flags;

	return 0;
}

/* hci_uart_tty_ioctl()
 *
 *    Process IOCTL system call for the tty device.
 *
 * Arguments:
 *
 *    tty        pointer to tty instance data
 *    file       pointer to open file object for device
 *    cmd        IOCTL command code
 *    arg        argument for IOCTL call (cmd dependent)
 *
 * Return Value:    Command dependent
 */
static int hci_uart_tty_ioctl(struct tty_struct *tty, struct file *file,
			      unsigned int cmd, unsigned long arg)
{
	struct hci_uart *hu = tty->disc_data;
	int err = 0;

	BT_DBG("");

	/* Verify the status of the device */
	if (!hu)
		return -EBADF;

	switch (cmd) {
	case HCIUARTSETPROTO:
		if (!test_and_set_bit(HCI_UART_PROTO_SET, &hu->flags)) {
			err = hci_uart_set_proto(hu, arg);
			if (err) {
				clear_bit(HCI_UART_PROTO_SET, &hu->flags);
				return err;
			}
		} else
			return -EBUSY;
		break;

	case HCIUARTGETPROTO:
		if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
			return hu->proto->id;
		return -EUNATCH;

	case HCIUARTGETDEVICE:
		if (test_bit(HCI_UART_REGISTERED, &hu->flags))
			return hu->hdev->id;
		return -EUNATCH;

	case HCIUARTSETFLAGS:
		if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
			return -EBUSY;
		err = hci_uart_set_flags(hu, arg);
		if (err)
			return err;
		break;

	case HCIUARTGETFLAGS:
		return hu->hdev_flags;

	default:
		err = n_tty_ioctl_helper(tty, file, cmd, arg);
		break;
	}

	return err;
}

/*
 * We don't provide read/write/poll interface for user space.
 */
static ssize_t hci_uart_tty_read(struct tty_struct *tty, struct file *file,
				 unsigned char __user *buf, size_t nr)
{
	return 0;
}

static ssize_t hci_uart_tty_write(struct tty_struct *tty, struct file *file,
				  const unsigned char *data, size_t count)
{
	return 0;
}

static unsigned int hci_uart_tty_poll(struct tty_struct *tty,
				      struct file *filp, poll_table *wait)
{
	return 0;
}

static int __init hci_uart_init(void)
{
	static struct tty_ldisc_ops hci_uart_ldisc;
	int err;

	BT_INFO("HCI UART driver ver %s", VERSION);

	/* Register the tty discipline */

	memset(&hci_uart_ldisc, 0, sizeof(hci_uart_ldisc));
	hci_uart_ldisc.magic		= TTY_LDISC_MAGIC;
	hci_uart_ldisc.name		= "n_hci";
	hci_uart_ldisc.open		= hci_uart_tty_open;
	hci_uart_ldisc.close		= hci_uart_tty_close;
	hci_uart_ldisc.read		= hci_uart_tty_read;
	hci_uart_ldisc.write		= hci_uart_tty_write;
	hci_uart_ldisc.ioctl		= hci_uart_tty_ioctl;
	hci_uart_ldisc.poll		= hci_uart_tty_poll;
	hci_uart_ldisc.receive_buf	= hci_uart_tty_receive;
	hci_uart_ldisc.write_wakeup	= hci_uart_tty_wakeup;
	hci_uart_ldisc.owner		= THIS_MODULE;

	err = tty_register_ldisc(N_HCI, &hci_uart_ldisc);
	if (err) {
		BT_ERR("HCI line discipline registration failed. (%d)", err);
		return err;
	}

#ifdef CONFIG_BT_HCIUART_H4
	h4_init();
#endif
#ifdef CONFIG_BT_HCIUART_BCSP
	bcsp_init();
#endif
#ifdef CONFIG_BT_HCIUART_LL
	ll_init();
#endif
#ifdef CONFIG_BT_HCIUART_ATH3K
	ath_init();
#endif
#ifdef CONFIG_BT_HCIUART_3WIRE
	h5_init();
#endif
#ifdef CONFIG_BT_HCIUART_INTEL
	intel_init();
#endif
#ifdef CONFIG_BT_HCIUART_BCM
	bcm_init();
#endif
#ifdef CONFIG_BT_HCIUART_QCA
	qca_init();
#endif

	return 0;
}

static void __exit hci_uart_exit(void)
{
	int err;

#ifdef CONFIG_BT_HCIUART_H4
	h4_deinit();
#endif
#ifdef CONFIG_BT_HCIUART_BCSP
	bcsp_deinit();
#endif
#ifdef CONFIG_BT_HCIUART_LL
	ll_deinit();
#endif
#ifdef CONFIG_BT_HCIUART_ATH3K
	ath_deinit();
#endif
#ifdef CONFIG_BT_HCIUART_3WIRE
	h5_deinit();
#endif
#ifdef CONFIG_BT_HCIUART_INTEL
	intel_deinit();
#endif
#ifdef CONFIG_BT_HCIUART_BCM
	bcm_deinit();
#endif
#ifdef CONFIG_BT_HCIUART_QCA
	qca_deinit();
#endif

	/* Release tty registration of line discipline */
	err = tty_unregister_ldisc(N_HCI);
	if (err)
		BT_ERR("Can't unregister HCI line discipline (%d)", err);
}

module_init(hci_uart_init);
module_exit(hci_uart_exit);

MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
MODULE_DESCRIPTION("Bluetooth HCI UART driver ver " VERSION);
MODULE_VERSION(VERSION);
MODULE_LICENSE("GPL");
MODULE_ALIAS_LDISC(N_HCI);