Merge tag 'for-linus-20181019' of git://git.kernel.dk/linux-block
[linux-2.6-block.git] / drivers / bluetooth / hci_ldisc.c
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 #include <linux/firmware.h>
44 #include <linux/serdev.h>
45
46 #include <net/bluetooth/bluetooth.h>
47 #include <net/bluetooth/hci_core.h>
48
49 #include "btintel.h"
50 #include "btbcm.h"
51 #include "hci_uart.h"
52
53 #define VERSION "2.3"
54
55 static const struct hci_uart_proto *hup[HCI_UART_MAX_PROTO];
56
57 int hci_uart_register_proto(const struct hci_uart_proto *p)
58 {
59         if (p->id >= HCI_UART_MAX_PROTO)
60                 return -EINVAL;
61
62         if (hup[p->id])
63                 return -EEXIST;
64
65         hup[p->id] = p;
66
67         BT_INFO("HCI UART protocol %s registered", p->name);
68
69         return 0;
70 }
71
72 int hci_uart_unregister_proto(const struct hci_uart_proto *p)
73 {
74         if (p->id >= HCI_UART_MAX_PROTO)
75                 return -EINVAL;
76
77         if (!hup[p->id])
78                 return -EINVAL;
79
80         hup[p->id] = NULL;
81
82         return 0;
83 }
84
85 static const struct hci_uart_proto *hci_uart_get_proto(unsigned int id)
86 {
87         if (id >= HCI_UART_MAX_PROTO)
88                 return NULL;
89
90         return hup[id];
91 }
92
93 static inline void hci_uart_tx_complete(struct hci_uart *hu, int pkt_type)
94 {
95         struct hci_dev *hdev = hu->hdev;
96
97         /* Update HCI stat counters */
98         switch (pkt_type) {
99         case HCI_COMMAND_PKT:
100                 hdev->stat.cmd_tx++;
101                 break;
102
103         case HCI_ACLDATA_PKT:
104                 hdev->stat.acl_tx++;
105                 break;
106
107         case HCI_SCODATA_PKT:
108                 hdev->stat.sco_tx++;
109                 break;
110         }
111 }
112
113 static inline struct sk_buff *hci_uart_dequeue(struct hci_uart *hu)
114 {
115         struct sk_buff *skb = hu->tx_skb;
116
117         if (!skb) {
118                 percpu_down_read(&hu->proto_lock);
119
120                 if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
121                         skb = hu->proto->dequeue(hu);
122
123                 percpu_up_read(&hu->proto_lock);
124         } else {
125                 hu->tx_skb = NULL;
126         }
127
128         return skb;
129 }
130
131 int hci_uart_tx_wakeup(struct hci_uart *hu)
132 {
133         /* This may be called in an IRQ context, so we can't sleep. Therefore
134          * we try to acquire the lock only, and if that fails we assume the
135          * tty is being closed because that is the only time the write lock is
136          * acquired. If, however, at some point in the future the write lock
137          * is also acquired in other situations, then this must be revisited.
138          */
139         if (!percpu_down_read_trylock(&hu->proto_lock))
140                 return 0;
141
142         if (!test_bit(HCI_UART_PROTO_READY, &hu->flags))
143                 goto no_schedule;
144
145         if (test_and_set_bit(HCI_UART_SENDING, &hu->tx_state)) {
146                 set_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
147                 goto no_schedule;
148         }
149
150         BT_DBG("");
151
152         schedule_work(&hu->write_work);
153
154 no_schedule:
155         percpu_up_read(&hu->proto_lock);
156
157         return 0;
158 }
159 EXPORT_SYMBOL_GPL(hci_uart_tx_wakeup);
160
161 static void hci_uart_write_work(struct work_struct *work)
162 {
163         struct hci_uart *hu = container_of(work, struct hci_uart, write_work);
164         struct tty_struct *tty = hu->tty;
165         struct hci_dev *hdev = hu->hdev;
166         struct sk_buff *skb;
167
168         /* REVISIT: should we cope with bad skbs or ->write() returning
169          * and error value ?
170          */
171
172 restart:
173         clear_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
174
175         while ((skb = hci_uart_dequeue(hu))) {
176                 int len;
177
178                 set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
179                 len = tty->ops->write(tty, skb->data, skb->len);
180                 hdev->stat.byte_tx += len;
181
182                 skb_pull(skb, len);
183                 if (skb->len) {
184                         hu->tx_skb = skb;
185                         break;
186                 }
187
188                 hci_uart_tx_complete(hu, hci_skb_pkt_type(skb));
189                 kfree_skb(skb);
190         }
191
192         if (test_bit(HCI_UART_TX_WAKEUP, &hu->tx_state))
193                 goto restart;
194
195         clear_bit(HCI_UART_SENDING, &hu->tx_state);
196 }
197
198 void hci_uart_init_work(struct work_struct *work)
199 {
200         struct hci_uart *hu = container_of(work, struct hci_uart, init_ready);
201         int err;
202         struct hci_dev *hdev;
203
204         if (!test_and_clear_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
205                 return;
206
207         err = hci_register_dev(hu->hdev);
208         if (err < 0) {
209                 BT_ERR("Can't register HCI device");
210                 hdev = hu->hdev;
211                 hu->hdev = NULL;
212                 hci_free_dev(hdev);
213                 clear_bit(HCI_UART_PROTO_READY, &hu->flags);
214                 hu->proto->close(hu);
215                 return;
216         }
217
218         set_bit(HCI_UART_REGISTERED, &hu->flags);
219 }
220
221 int hci_uart_init_ready(struct hci_uart *hu)
222 {
223         if (!test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
224                 return -EALREADY;
225
226         schedule_work(&hu->init_ready);
227
228         return 0;
229 }
230
231 /* ------- Interface to HCI layer ------ */
232 /* Reset device */
233 static int hci_uart_flush(struct hci_dev *hdev)
234 {
235         struct hci_uart *hu  = hci_get_drvdata(hdev);
236         struct tty_struct *tty = hu->tty;
237
238         BT_DBG("hdev %p tty %p", hdev, tty);
239
240         if (hu->tx_skb) {
241                 kfree_skb(hu->tx_skb); hu->tx_skb = NULL;
242         }
243
244         /* Flush any pending characters in the driver and discipline. */
245         tty_ldisc_flush(tty);
246         tty_driver_flush_buffer(tty);
247
248         percpu_down_read(&hu->proto_lock);
249
250         if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
251                 hu->proto->flush(hu);
252
253         percpu_up_read(&hu->proto_lock);
254
255         return 0;
256 }
257
258 /* Initialize device */
259 static int hci_uart_open(struct hci_dev *hdev)
260 {
261         BT_DBG("%s %p", hdev->name, hdev);
262
263         /* Undo clearing this from hci_uart_close() */
264         hdev->flush = hci_uart_flush;
265
266         return 0;
267 }
268
269 /* Close device */
270 static int hci_uart_close(struct hci_dev *hdev)
271 {
272         BT_DBG("hdev %p", hdev);
273
274         hci_uart_flush(hdev);
275         hdev->flush = NULL;
276         return 0;
277 }
278
279 /* Send frames from HCI layer */
280 static int hci_uart_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
281 {
282         struct hci_uart *hu = hci_get_drvdata(hdev);
283
284         BT_DBG("%s: type %d len %d", hdev->name, hci_skb_pkt_type(skb),
285                skb->len);
286
287         percpu_down_read(&hu->proto_lock);
288
289         if (!test_bit(HCI_UART_PROTO_READY, &hu->flags)) {
290                 percpu_up_read(&hu->proto_lock);
291                 return -EUNATCH;
292         }
293
294         hu->proto->enqueue(hu, skb);
295         percpu_up_read(&hu->proto_lock);
296
297         hci_uart_tx_wakeup(hu);
298
299         return 0;
300 }
301
302 /* Flow control or un-flow control the device */
303 void hci_uart_set_flow_control(struct hci_uart *hu, bool enable)
304 {
305         struct tty_struct *tty = hu->tty;
306         struct ktermios ktermios;
307         int status;
308         unsigned int set = 0;
309         unsigned int clear = 0;
310
311         if (hu->serdev) {
312                 serdev_device_set_flow_control(hu->serdev, !enable);
313                 serdev_device_set_rts(hu->serdev, !enable);
314                 return;
315         }
316
317         if (enable) {
318                 /* Disable hardware flow control */
319                 ktermios = tty->termios;
320                 ktermios.c_cflag &= ~CRTSCTS;
321                 status = tty_set_termios(tty, &ktermios);
322                 BT_DBG("Disabling hardware flow control: %s",
323                        status ? "failed" : "success");
324
325                 /* Clear RTS to prevent the device from sending */
326                 /* Most UARTs need OUT2 to enable interrupts */
327                 status = tty->driver->ops->tiocmget(tty);
328                 BT_DBG("Current tiocm 0x%x", status);
329
330                 set &= ~(TIOCM_OUT2 | TIOCM_RTS);
331                 clear = ~set;
332                 set &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
333                        TIOCM_OUT2 | TIOCM_LOOP;
334                 clear &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
335                          TIOCM_OUT2 | TIOCM_LOOP;
336                 status = tty->driver->ops->tiocmset(tty, set, clear);
337                 BT_DBG("Clearing RTS: %s", status ? "failed" : "success");
338         } else {
339                 /* Set RTS to allow the device to send again */
340                 status = tty->driver->ops->tiocmget(tty);
341                 BT_DBG("Current tiocm 0x%x", status);
342
343                 set |= (TIOCM_OUT2 | TIOCM_RTS);
344                 clear = ~set;
345                 set &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
346                        TIOCM_OUT2 | TIOCM_LOOP;
347                 clear &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
348                          TIOCM_OUT2 | TIOCM_LOOP;
349                 status = tty->driver->ops->tiocmset(tty, set, clear);
350                 BT_DBG("Setting RTS: %s", status ? "failed" : "success");
351
352                 /* Re-enable hardware flow control */
353                 ktermios = tty->termios;
354                 ktermios.c_cflag |= CRTSCTS;
355                 status = tty_set_termios(tty, &ktermios);
356                 BT_DBG("Enabling hardware flow control: %s",
357                        status ? "failed" : "success");
358         }
359 }
360
361 void hci_uart_set_speeds(struct hci_uart *hu, unsigned int init_speed,
362                          unsigned int oper_speed)
363 {
364         hu->init_speed = init_speed;
365         hu->oper_speed = oper_speed;
366 }
367
368 void hci_uart_set_baudrate(struct hci_uart *hu, unsigned int speed)
369 {
370         struct tty_struct *tty = hu->tty;
371         struct ktermios ktermios;
372
373         ktermios = tty->termios;
374         ktermios.c_cflag &= ~CBAUD;
375         tty_termios_encode_baud_rate(&ktermios, speed, speed);
376
377         /* tty_set_termios() return not checked as it is always 0 */
378         tty_set_termios(tty, &ktermios);
379
380         BT_DBG("%s: New tty speeds: %d/%d", hu->hdev->name,
381                tty->termios.c_ispeed, tty->termios.c_ospeed);
382 }
383
384 static int hci_uart_setup(struct hci_dev *hdev)
385 {
386         struct hci_uart *hu = hci_get_drvdata(hdev);
387         struct hci_rp_read_local_version *ver;
388         struct sk_buff *skb;
389         unsigned int speed;
390         int err;
391
392         /* Init speed if any */
393         if (hu->init_speed)
394                 speed = hu->init_speed;
395         else if (hu->proto->init_speed)
396                 speed = hu->proto->init_speed;
397         else
398                 speed = 0;
399
400         if (speed)
401                 hci_uart_set_baudrate(hu, speed);
402
403         /* Operational speed if any */
404         if (hu->oper_speed)
405                 speed = hu->oper_speed;
406         else if (hu->proto->oper_speed)
407                 speed = hu->proto->oper_speed;
408         else
409                 speed = 0;
410
411         if (hu->proto->set_baudrate && speed) {
412                 err = hu->proto->set_baudrate(hu, speed);
413                 if (!err)
414                         hci_uart_set_baudrate(hu, speed);
415         }
416
417         if (hu->proto->setup)
418                 return hu->proto->setup(hu);
419
420         if (!test_bit(HCI_UART_VND_DETECT, &hu->hdev_flags))
421                 return 0;
422
423         skb = __hci_cmd_sync(hdev, HCI_OP_READ_LOCAL_VERSION, 0, NULL,
424                              HCI_INIT_TIMEOUT);
425         if (IS_ERR(skb)) {
426                 BT_ERR("%s: Reading local version information failed (%ld)",
427                        hdev->name, PTR_ERR(skb));
428                 return 0;
429         }
430
431         if (skb->len != sizeof(*ver)) {
432                 BT_ERR("%s: Event length mismatch for version information",
433                        hdev->name);
434                 goto done;
435         }
436
437         ver = (struct hci_rp_read_local_version *)skb->data;
438
439         switch (le16_to_cpu(ver->manufacturer)) {
440 #ifdef CONFIG_BT_HCIUART_INTEL
441         case 2:
442                 hdev->set_bdaddr = btintel_set_bdaddr;
443                 btintel_check_bdaddr(hdev);
444                 break;
445 #endif
446 #ifdef CONFIG_BT_HCIUART_BCM
447         case 15:
448                 hdev->set_bdaddr = btbcm_set_bdaddr;
449                 btbcm_check_bdaddr(hdev);
450                 break;
451 #endif
452         default:
453                 break;
454         }
455
456 done:
457         kfree_skb(skb);
458         return 0;
459 }
460
461 /* ------ LDISC part ------ */
462 /* hci_uart_tty_open
463  *
464  *     Called when line discipline changed to HCI_UART.
465  *
466  * Arguments:
467  *     tty    pointer to tty info structure
468  * Return Value:
469  *     0 if success, otherwise error code
470  */
471 static int hci_uart_tty_open(struct tty_struct *tty)
472 {
473         struct hci_uart *hu;
474
475         BT_DBG("tty %p", tty);
476
477         /* Error if the tty has no write op instead of leaving an exploitable
478          * hole
479          */
480         if (tty->ops->write == NULL)
481                 return -EOPNOTSUPP;
482
483         hu = kzalloc(sizeof(struct hci_uart), GFP_KERNEL);
484         if (!hu) {
485                 BT_ERR("Can't allocate control structure");
486                 return -ENFILE;
487         }
488
489         tty->disc_data = hu;
490         hu->tty = tty;
491         tty->receive_room = 65536;
492
493         /* disable alignment support by default */
494         hu->alignment = 1;
495         hu->padding = 0;
496
497         INIT_WORK(&hu->init_ready, hci_uart_init_work);
498         INIT_WORK(&hu->write_work, hci_uart_write_work);
499
500         percpu_init_rwsem(&hu->proto_lock);
501
502         /* Flush any pending characters in the driver */
503         tty_driver_flush_buffer(tty);
504
505         return 0;
506 }
507
508 /* hci_uart_tty_close()
509  *
510  *    Called when the line discipline is changed to something
511  *    else, the tty is closed, or the tty detects a hangup.
512  */
513 static void hci_uart_tty_close(struct tty_struct *tty)
514 {
515         struct hci_uart *hu = tty->disc_data;
516         struct hci_dev *hdev;
517
518         BT_DBG("tty %p", tty);
519
520         /* Detach from the tty */
521         tty->disc_data = NULL;
522
523         if (!hu)
524                 return;
525
526         hdev = hu->hdev;
527         if (hdev)
528                 hci_uart_close(hdev);
529
530         if (test_bit(HCI_UART_PROTO_READY, &hu->flags)) {
531                 percpu_down_write(&hu->proto_lock);
532                 clear_bit(HCI_UART_PROTO_READY, &hu->flags);
533                 percpu_up_write(&hu->proto_lock);
534
535                 cancel_work_sync(&hu->write_work);
536
537                 if (hdev) {
538                         if (test_bit(HCI_UART_REGISTERED, &hu->flags))
539                                 hci_unregister_dev(hdev);
540                         hci_free_dev(hdev);
541                 }
542                 hu->proto->close(hu);
543         }
544         clear_bit(HCI_UART_PROTO_SET, &hu->flags);
545
546         percpu_free_rwsem(&hu->proto_lock);
547
548         kfree(hu);
549 }
550
551 /* hci_uart_tty_wakeup()
552  *
553  *    Callback for transmit wakeup. Called when low level
554  *    device driver can accept more send data.
555  *
556  * Arguments:        tty    pointer to associated tty instance data
557  * Return Value:    None
558  */
559 static void hci_uart_tty_wakeup(struct tty_struct *tty)
560 {
561         struct hci_uart *hu = tty->disc_data;
562
563         BT_DBG("");
564
565         if (!hu)
566                 return;
567
568         clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
569
570         if (tty != hu->tty)
571                 return;
572
573         if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
574                 hci_uart_tx_wakeup(hu);
575 }
576
577 /* hci_uart_tty_receive()
578  *
579  *     Called by tty low level driver when receive data is
580  *     available.
581  *
582  * Arguments:  tty          pointer to tty isntance data
583  *             data         pointer to received data
584  *             flags        pointer to flags for data
585  *             count        count of received data in bytes
586  *
587  * Return Value:    None
588  */
589 static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data,
590                                  char *flags, int count)
591 {
592         struct hci_uart *hu = tty->disc_data;
593
594         if (!hu || tty != hu->tty)
595                 return;
596
597         percpu_down_read(&hu->proto_lock);
598
599         if (!test_bit(HCI_UART_PROTO_READY, &hu->flags)) {
600                 percpu_up_read(&hu->proto_lock);
601                 return;
602         }
603
604         /* It does not need a lock here as it is already protected by a mutex in
605          * tty caller
606          */
607         hu->proto->recv(hu, data, count);
608         percpu_up_read(&hu->proto_lock);
609
610         if (hu->hdev)
611                 hu->hdev->stat.byte_rx += count;
612
613         tty_unthrottle(tty);
614 }
615
616 static int hci_uart_register_dev(struct hci_uart *hu)
617 {
618         struct hci_dev *hdev;
619
620         BT_DBG("");
621
622         /* Initialize and register HCI device */
623         hdev = hci_alloc_dev();
624         if (!hdev) {
625                 BT_ERR("Can't allocate HCI device");
626                 return -ENOMEM;
627         }
628
629         hu->hdev = hdev;
630
631         hdev->bus = HCI_UART;
632         hci_set_drvdata(hdev, hu);
633
634         /* Only when vendor specific setup callback is provided, consider
635          * the manufacturer information valid. This avoids filling in the
636          * value for Ericsson when nothing is specified.
637          */
638         if (hu->proto->setup)
639                 hdev->manufacturer = hu->proto->manufacturer;
640
641         hdev->open  = hci_uart_open;
642         hdev->close = hci_uart_close;
643         hdev->flush = hci_uart_flush;
644         hdev->send  = hci_uart_send_frame;
645         hdev->setup = hci_uart_setup;
646         SET_HCIDEV_DEV(hdev, hu->tty->dev);
647
648         if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags))
649                 set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
650
651         if (test_bit(HCI_UART_EXT_CONFIG, &hu->hdev_flags))
652                 set_bit(HCI_QUIRK_EXTERNAL_CONFIG, &hdev->quirks);
653
654         if (!test_bit(HCI_UART_RESET_ON_INIT, &hu->hdev_flags))
655                 set_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks);
656
657         if (test_bit(HCI_UART_CREATE_AMP, &hu->hdev_flags))
658                 hdev->dev_type = HCI_AMP;
659         else
660                 hdev->dev_type = HCI_PRIMARY;
661
662         if (test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
663                 return 0;
664
665         if (hci_register_dev(hdev) < 0) {
666                 BT_ERR("Can't register HCI device");
667                 hu->hdev = NULL;
668                 hci_free_dev(hdev);
669                 return -ENODEV;
670         }
671
672         set_bit(HCI_UART_REGISTERED, &hu->flags);
673
674         return 0;
675 }
676
677 static int hci_uart_set_proto(struct hci_uart *hu, int id)
678 {
679         const struct hci_uart_proto *p;
680         int err;
681
682         p = hci_uart_get_proto(id);
683         if (!p)
684                 return -EPROTONOSUPPORT;
685
686         err = p->open(hu);
687         if (err)
688                 return err;
689
690         hu->proto = p;
691         set_bit(HCI_UART_PROTO_READY, &hu->flags);
692
693         err = hci_uart_register_dev(hu);
694         if (err) {
695                 clear_bit(HCI_UART_PROTO_READY, &hu->flags);
696                 p->close(hu);
697                 return err;
698         }
699
700         return 0;
701 }
702
703 static int hci_uart_set_flags(struct hci_uart *hu, unsigned long flags)
704 {
705         unsigned long valid_flags = BIT(HCI_UART_RAW_DEVICE) |
706                                     BIT(HCI_UART_RESET_ON_INIT) |
707                                     BIT(HCI_UART_CREATE_AMP) |
708                                     BIT(HCI_UART_INIT_PENDING) |
709                                     BIT(HCI_UART_EXT_CONFIG) |
710                                     BIT(HCI_UART_VND_DETECT);
711
712         if (flags & ~valid_flags)
713                 return -EINVAL;
714
715         hu->hdev_flags = flags;
716
717         return 0;
718 }
719
720 /* hci_uart_tty_ioctl()
721  *
722  *    Process IOCTL system call for the tty device.
723  *
724  * Arguments:
725  *
726  *    tty        pointer to tty instance data
727  *    file       pointer to open file object for device
728  *    cmd        IOCTL command code
729  *    arg        argument for IOCTL call (cmd dependent)
730  *
731  * Return Value:    Command dependent
732  */
733 static int hci_uart_tty_ioctl(struct tty_struct *tty, struct file *file,
734                               unsigned int cmd, unsigned long arg)
735 {
736         struct hci_uart *hu = tty->disc_data;
737         int err = 0;
738
739         BT_DBG("");
740
741         /* Verify the status of the device */
742         if (!hu)
743                 return -EBADF;
744
745         switch (cmd) {
746         case HCIUARTSETPROTO:
747                 if (!test_and_set_bit(HCI_UART_PROTO_SET, &hu->flags)) {
748                         err = hci_uart_set_proto(hu, arg);
749                         if (err)
750                                 clear_bit(HCI_UART_PROTO_SET, &hu->flags);
751                 } else
752                         err = -EBUSY;
753                 break;
754
755         case HCIUARTGETPROTO:
756                 if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
757                         err = hu->proto->id;
758                 else
759                         err = -EUNATCH;
760                 break;
761
762         case HCIUARTGETDEVICE:
763                 if (test_bit(HCI_UART_REGISTERED, &hu->flags))
764                         err = hu->hdev->id;
765                 else
766                         err = -EUNATCH;
767                 break;
768
769         case HCIUARTSETFLAGS:
770                 if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
771                         err = -EBUSY;
772                 else
773                         err = hci_uart_set_flags(hu, arg);
774                 break;
775
776         case HCIUARTGETFLAGS:
777                 err = hu->hdev_flags;
778                 break;
779
780         default:
781                 err = n_tty_ioctl_helper(tty, file, cmd, arg);
782                 break;
783         }
784
785         return err;
786 }
787
788 /*
789  * We don't provide read/write/poll interface for user space.
790  */
791 static ssize_t hci_uart_tty_read(struct tty_struct *tty, struct file *file,
792                                  unsigned char __user *buf, size_t nr)
793 {
794         return 0;
795 }
796
797 static ssize_t hci_uart_tty_write(struct tty_struct *tty, struct file *file,
798                                   const unsigned char *data, size_t count)
799 {
800         return 0;
801 }
802
803 static __poll_t hci_uart_tty_poll(struct tty_struct *tty,
804                                       struct file *filp, poll_table *wait)
805 {
806         return 0;
807 }
808
809 static int __init hci_uart_init(void)
810 {
811         static struct tty_ldisc_ops hci_uart_ldisc;
812         int err;
813
814         BT_INFO("HCI UART driver ver %s", VERSION);
815
816         /* Register the tty discipline */
817
818         memset(&hci_uart_ldisc, 0, sizeof(hci_uart_ldisc));
819         hci_uart_ldisc.magic            = TTY_LDISC_MAGIC;
820         hci_uart_ldisc.name             = "n_hci";
821         hci_uart_ldisc.open             = hci_uart_tty_open;
822         hci_uart_ldisc.close            = hci_uart_tty_close;
823         hci_uart_ldisc.read             = hci_uart_tty_read;
824         hci_uart_ldisc.write            = hci_uart_tty_write;
825         hci_uart_ldisc.ioctl            = hci_uart_tty_ioctl;
826         hci_uart_ldisc.poll             = hci_uart_tty_poll;
827         hci_uart_ldisc.receive_buf      = hci_uart_tty_receive;
828         hci_uart_ldisc.write_wakeup     = hci_uart_tty_wakeup;
829         hci_uart_ldisc.owner            = THIS_MODULE;
830
831         err = tty_register_ldisc(N_HCI, &hci_uart_ldisc);
832         if (err) {
833                 BT_ERR("HCI line discipline registration failed. (%d)", err);
834                 return err;
835         }
836
837 #ifdef CONFIG_BT_HCIUART_H4
838         h4_init();
839 #endif
840 #ifdef CONFIG_BT_HCIUART_BCSP
841         bcsp_init();
842 #endif
843 #ifdef CONFIG_BT_HCIUART_LL
844         ll_init();
845 #endif
846 #ifdef CONFIG_BT_HCIUART_ATH3K
847         ath_init();
848 #endif
849 #ifdef CONFIG_BT_HCIUART_3WIRE
850         h5_init();
851 #endif
852 #ifdef CONFIG_BT_HCIUART_INTEL
853         intel_init();
854 #endif
855 #ifdef CONFIG_BT_HCIUART_BCM
856         bcm_init();
857 #endif
858 #ifdef CONFIG_BT_HCIUART_QCA
859         qca_init();
860 #endif
861 #ifdef CONFIG_BT_HCIUART_AG6XX
862         ag6xx_init();
863 #endif
864 #ifdef CONFIG_BT_HCIUART_MRVL
865         mrvl_init();
866 #endif
867
868         return 0;
869 }
870
871 static void __exit hci_uart_exit(void)
872 {
873         int err;
874
875 #ifdef CONFIG_BT_HCIUART_H4
876         h4_deinit();
877 #endif
878 #ifdef CONFIG_BT_HCIUART_BCSP
879         bcsp_deinit();
880 #endif
881 #ifdef CONFIG_BT_HCIUART_LL
882         ll_deinit();
883 #endif
884 #ifdef CONFIG_BT_HCIUART_ATH3K
885         ath_deinit();
886 #endif
887 #ifdef CONFIG_BT_HCIUART_3WIRE
888         h5_deinit();
889 #endif
890 #ifdef CONFIG_BT_HCIUART_INTEL
891         intel_deinit();
892 #endif
893 #ifdef CONFIG_BT_HCIUART_BCM
894         bcm_deinit();
895 #endif
896 #ifdef CONFIG_BT_HCIUART_QCA
897         qca_deinit();
898 #endif
899 #ifdef CONFIG_BT_HCIUART_AG6XX
900         ag6xx_deinit();
901 #endif
902 #ifdef CONFIG_BT_HCIUART_MRVL
903         mrvl_deinit();
904 #endif
905
906         /* Release tty registration of line discipline */
907         err = tty_unregister_ldisc(N_HCI);
908         if (err)
909                 BT_ERR("Can't unregister HCI line discipline (%d)", err);
910 }
911
912 module_init(hci_uart_init);
913 module_exit(hci_uart_exit);
914
915 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
916 MODULE_DESCRIPTION("Bluetooth HCI UART driver ver " VERSION);
917 MODULE_VERSION(VERSION);
918 MODULE_LICENSE("GPL");
919 MODULE_ALIAS_LDISC(N_HCI);