xref: /openbmc/linux/drivers/bluetooth/hci_ldisc.c (revision 6aa7de05)
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 
45 #include <net/bluetooth/bluetooth.h>
46 #include <net/bluetooth/hci_core.h>
47 
48 #include "btintel.h"
49 #include "btbcm.h"
50 #include "hci_uart.h"
51 
52 #define VERSION "2.3"
53 
54 static const struct hci_uart_proto *hup[HCI_UART_MAX_PROTO];
55 
56 int hci_uart_register_proto(const struct hci_uart_proto *p)
57 {
58 	if (p->id >= HCI_UART_MAX_PROTO)
59 		return -EINVAL;
60 
61 	if (hup[p->id])
62 		return -EEXIST;
63 
64 	hup[p->id] = p;
65 
66 	BT_INFO("HCI UART protocol %s registered", p->name);
67 
68 	return 0;
69 }
70 
71 int hci_uart_unregister_proto(const struct hci_uart_proto *p)
72 {
73 	if (p->id >= HCI_UART_MAX_PROTO)
74 		return -EINVAL;
75 
76 	if (!hup[p->id])
77 		return -EINVAL;
78 
79 	hup[p->id] = NULL;
80 
81 	return 0;
82 }
83 
84 static const struct hci_uart_proto *hci_uart_get_proto(unsigned int id)
85 {
86 	if (id >= HCI_UART_MAX_PROTO)
87 		return NULL;
88 
89 	return hup[id];
90 }
91 
92 static inline void hci_uart_tx_complete(struct hci_uart *hu, int pkt_type)
93 {
94 	struct hci_dev *hdev = hu->hdev;
95 
96 	/* Update HCI stat counters */
97 	switch (pkt_type) {
98 	case HCI_COMMAND_PKT:
99 		hdev->stat.cmd_tx++;
100 		break;
101 
102 	case HCI_ACLDATA_PKT:
103 		hdev->stat.acl_tx++;
104 		break;
105 
106 	case HCI_SCODATA_PKT:
107 		hdev->stat.sco_tx++;
108 		break;
109 	}
110 }
111 
112 static inline struct sk_buff *hci_uart_dequeue(struct hci_uart *hu)
113 {
114 	struct sk_buff *skb = hu->tx_skb;
115 
116 	if (!skb) {
117 		read_lock(&hu->proto_lock);
118 
119 		if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
120 			skb = hu->proto->dequeue(hu);
121 
122 		read_unlock(&hu->proto_lock);
123 	} else {
124 		hu->tx_skb = NULL;
125 	}
126 
127 	return skb;
128 }
129 
130 int hci_uart_tx_wakeup(struct hci_uart *hu)
131 {
132 	read_lock(&hu->proto_lock);
133 
134 	if (!test_bit(HCI_UART_PROTO_READY, &hu->flags))
135 		goto no_schedule;
136 
137 	if (test_and_set_bit(HCI_UART_SENDING, &hu->tx_state)) {
138 		set_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
139 		goto no_schedule;
140 	}
141 
142 	BT_DBG("");
143 
144 	schedule_work(&hu->write_work);
145 
146 no_schedule:
147 	read_unlock(&hu->proto_lock);
148 
149 	return 0;
150 }
151 EXPORT_SYMBOL_GPL(hci_uart_tx_wakeup);
152 
153 static void hci_uart_write_work(struct work_struct *work)
154 {
155 	struct hci_uart *hu = container_of(work, struct hci_uart, write_work);
156 	struct tty_struct *tty = hu->tty;
157 	struct hci_dev *hdev = hu->hdev;
158 	struct sk_buff *skb;
159 
160 	/* REVISIT: should we cope with bad skbs or ->write() returning
161 	 * and error value ?
162 	 */
163 
164 restart:
165 	clear_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
166 
167 	while ((skb = hci_uart_dequeue(hu))) {
168 		int len;
169 
170 		set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
171 		len = tty->ops->write(tty, skb->data, skb->len);
172 		hdev->stat.byte_tx += len;
173 
174 		skb_pull(skb, len);
175 		if (skb->len) {
176 			hu->tx_skb = skb;
177 			break;
178 		}
179 
180 		hci_uart_tx_complete(hu, hci_skb_pkt_type(skb));
181 		kfree_skb(skb);
182 	}
183 
184 	if (test_bit(HCI_UART_TX_WAKEUP, &hu->tx_state))
185 		goto restart;
186 
187 	clear_bit(HCI_UART_SENDING, &hu->tx_state);
188 }
189 
190 static void hci_uart_init_work(struct work_struct *work)
191 {
192 	struct hci_uart *hu = container_of(work, struct hci_uart, init_ready);
193 	int err;
194 	struct hci_dev *hdev;
195 
196 	if (!test_and_clear_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
197 		return;
198 
199 	err = hci_register_dev(hu->hdev);
200 	if (err < 0) {
201 		BT_ERR("Can't register HCI device");
202 		hdev = hu->hdev;
203 		hu->hdev = NULL;
204 		hci_free_dev(hdev);
205 		clear_bit(HCI_UART_PROTO_READY, &hu->flags);
206 		hu->proto->close(hu);
207 		return;
208 	}
209 
210 	set_bit(HCI_UART_REGISTERED, &hu->flags);
211 }
212 
213 int hci_uart_init_ready(struct hci_uart *hu)
214 {
215 	if (!test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
216 		return -EALREADY;
217 
218 	schedule_work(&hu->init_ready);
219 
220 	return 0;
221 }
222 
223 /* ------- Interface to HCI layer ------ */
224 /* Initialize device */
225 static int hci_uart_open(struct hci_dev *hdev)
226 {
227 	BT_DBG("%s %p", hdev->name, hdev);
228 
229 	/* Nothing to do for UART driver */
230 	return 0;
231 }
232 
233 /* Reset device */
234 static int hci_uart_flush(struct hci_dev *hdev)
235 {
236 	struct hci_uart *hu  = hci_get_drvdata(hdev);
237 	struct tty_struct *tty = hu->tty;
238 
239 	BT_DBG("hdev %p tty %p", hdev, tty);
240 
241 	if (hu->tx_skb) {
242 		kfree_skb(hu->tx_skb); hu->tx_skb = NULL;
243 	}
244 
245 	/* Flush any pending characters in the driver and discipline. */
246 	tty_ldisc_flush(tty);
247 	tty_driver_flush_buffer(tty);
248 
249 	read_lock(&hu->proto_lock);
250 
251 	if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
252 		hu->proto->flush(hu);
253 
254 	read_unlock(&hu->proto_lock);
255 
256 	return 0;
257 }
258 
259 /* Close device */
260 static int hci_uart_close(struct hci_dev *hdev)
261 {
262 	BT_DBG("hdev %p", hdev);
263 
264 	hci_uart_flush(hdev);
265 	hdev->flush = NULL;
266 	return 0;
267 }
268 
269 /* Send frames from HCI layer */
270 static int hci_uart_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
271 {
272 	struct hci_uart *hu = hci_get_drvdata(hdev);
273 
274 	BT_DBG("%s: type %d len %d", hdev->name, hci_skb_pkt_type(skb),
275 	       skb->len);
276 
277 	read_lock(&hu->proto_lock);
278 
279 	if (!test_bit(HCI_UART_PROTO_READY, &hu->flags)) {
280 		read_unlock(&hu->proto_lock);
281 		return -EUNATCH;
282 	}
283 
284 	hu->proto->enqueue(hu, skb);
285 	read_unlock(&hu->proto_lock);
286 
287 	hci_uart_tx_wakeup(hu);
288 
289 	return 0;
290 }
291 
292 /* Flow control or un-flow control the device */
293 void hci_uart_set_flow_control(struct hci_uart *hu, bool enable)
294 {
295 	struct tty_struct *tty = hu->tty;
296 	struct ktermios ktermios;
297 	int status;
298 	unsigned int set = 0;
299 	unsigned int clear = 0;
300 
301 	if (enable) {
302 		/* Disable hardware flow control */
303 		ktermios = tty->termios;
304 		ktermios.c_cflag &= ~CRTSCTS;
305 		status = tty_set_termios(tty, &ktermios);
306 		BT_DBG("Disabling hardware flow control: %s",
307 		       status ? "failed" : "success");
308 
309 		/* Clear RTS to prevent the device from sending */
310 		/* Most UARTs need OUT2 to enable interrupts */
311 		status = tty->driver->ops->tiocmget(tty);
312 		BT_DBG("Current tiocm 0x%x", status);
313 
314 		set &= ~(TIOCM_OUT2 | TIOCM_RTS);
315 		clear = ~set;
316 		set &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
317 		       TIOCM_OUT2 | TIOCM_LOOP;
318 		clear &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
319 			 TIOCM_OUT2 | TIOCM_LOOP;
320 		status = tty->driver->ops->tiocmset(tty, set, clear);
321 		BT_DBG("Clearing RTS: %s", status ? "failed" : "success");
322 	} else {
323 		/* Set RTS to allow the device to send again */
324 		status = tty->driver->ops->tiocmget(tty);
325 		BT_DBG("Current tiocm 0x%x", status);
326 
327 		set |= (TIOCM_OUT2 | TIOCM_RTS);
328 		clear = ~set;
329 		set &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
330 		       TIOCM_OUT2 | TIOCM_LOOP;
331 		clear &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
332 			 TIOCM_OUT2 | TIOCM_LOOP;
333 		status = tty->driver->ops->tiocmset(tty, set, clear);
334 		BT_DBG("Setting RTS: %s", status ? "failed" : "success");
335 
336 		/* Re-enable hardware flow control */
337 		ktermios = tty->termios;
338 		ktermios.c_cflag |= CRTSCTS;
339 		status = tty_set_termios(tty, &ktermios);
340 		BT_DBG("Enabling hardware flow control: %s",
341 		       status ? "failed" : "success");
342 	}
343 }
344 
345 void hci_uart_set_speeds(struct hci_uart *hu, unsigned int init_speed,
346 			 unsigned int oper_speed)
347 {
348 	hu->init_speed = init_speed;
349 	hu->oper_speed = oper_speed;
350 }
351 
352 void hci_uart_set_baudrate(struct hci_uart *hu, unsigned int speed)
353 {
354 	struct tty_struct *tty = hu->tty;
355 	struct ktermios ktermios;
356 
357 	ktermios = tty->termios;
358 	ktermios.c_cflag &= ~CBAUD;
359 	tty_termios_encode_baud_rate(&ktermios, speed, speed);
360 
361 	/* tty_set_termios() return not checked as it is always 0 */
362 	tty_set_termios(tty, &ktermios);
363 
364 	BT_DBG("%s: New tty speeds: %d/%d", hu->hdev->name,
365 	       tty->termios.c_ispeed, tty->termios.c_ospeed);
366 }
367 
368 static int hci_uart_setup(struct hci_dev *hdev)
369 {
370 	struct hci_uart *hu = hci_get_drvdata(hdev);
371 	struct hci_rp_read_local_version *ver;
372 	struct sk_buff *skb;
373 	unsigned int speed;
374 	int err;
375 
376 	/* Init speed if any */
377 	if (hu->init_speed)
378 		speed = hu->init_speed;
379 	else if (hu->proto->init_speed)
380 		speed = hu->proto->init_speed;
381 	else
382 		speed = 0;
383 
384 	if (speed)
385 		hci_uart_set_baudrate(hu, speed);
386 
387 	/* Operational speed if any */
388 	if (hu->oper_speed)
389 		speed = hu->oper_speed;
390 	else if (hu->proto->oper_speed)
391 		speed = hu->proto->oper_speed;
392 	else
393 		speed = 0;
394 
395 	if (hu->proto->set_baudrate && speed) {
396 		err = hu->proto->set_baudrate(hu, speed);
397 		if (!err)
398 			hci_uart_set_baudrate(hu, speed);
399 	}
400 
401 	if (hu->proto->setup)
402 		return hu->proto->setup(hu);
403 
404 	if (!test_bit(HCI_UART_VND_DETECT, &hu->hdev_flags))
405 		return 0;
406 
407 	skb = __hci_cmd_sync(hdev, HCI_OP_READ_LOCAL_VERSION, 0, NULL,
408 			     HCI_INIT_TIMEOUT);
409 	if (IS_ERR(skb)) {
410 		BT_ERR("%s: Reading local version information failed (%ld)",
411 		       hdev->name, PTR_ERR(skb));
412 		return 0;
413 	}
414 
415 	if (skb->len != sizeof(*ver)) {
416 		BT_ERR("%s: Event length mismatch for version information",
417 		       hdev->name);
418 		goto done;
419 	}
420 
421 	ver = (struct hci_rp_read_local_version *)skb->data;
422 
423 	switch (le16_to_cpu(ver->manufacturer)) {
424 #ifdef CONFIG_BT_HCIUART_INTEL
425 	case 2:
426 		hdev->set_bdaddr = btintel_set_bdaddr;
427 		btintel_check_bdaddr(hdev);
428 		break;
429 #endif
430 #ifdef CONFIG_BT_HCIUART_BCM
431 	case 15:
432 		hdev->set_bdaddr = btbcm_set_bdaddr;
433 		btbcm_check_bdaddr(hdev);
434 		break;
435 #endif
436 	}
437 
438 done:
439 	kfree_skb(skb);
440 	return 0;
441 }
442 
443 /* ------ LDISC part ------ */
444 /* hci_uart_tty_open
445  *
446  *     Called when line discipline changed to HCI_UART.
447  *
448  * Arguments:
449  *     tty    pointer to tty info structure
450  * Return Value:
451  *     0 if success, otherwise error code
452  */
453 static int hci_uart_tty_open(struct tty_struct *tty)
454 {
455 	struct hci_uart *hu;
456 
457 	BT_DBG("tty %p", tty);
458 
459 	/* Error if the tty has no write op instead of leaving an exploitable
460 	 * hole
461 	 */
462 	if (tty->ops->write == NULL)
463 		return -EOPNOTSUPP;
464 
465 	hu = kzalloc(sizeof(struct hci_uart), GFP_KERNEL);
466 	if (!hu) {
467 		BT_ERR("Can't allocate control structure");
468 		return -ENFILE;
469 	}
470 
471 	tty->disc_data = hu;
472 	hu->tty = tty;
473 	tty->receive_room = 65536;
474 
475 	/* disable alignment support by default */
476 	hu->alignment = 1;
477 	hu->padding = 0;
478 
479 	INIT_WORK(&hu->init_ready, hci_uart_init_work);
480 	INIT_WORK(&hu->write_work, hci_uart_write_work);
481 
482 	rwlock_init(&hu->proto_lock);
483 
484 	/* Flush any pending characters in the driver */
485 	tty_driver_flush_buffer(tty);
486 
487 	return 0;
488 }
489 
490 /* hci_uart_tty_close()
491  *
492  *    Called when the line discipline is changed to something
493  *    else, the tty is closed, or the tty detects a hangup.
494  */
495 static void hci_uart_tty_close(struct tty_struct *tty)
496 {
497 	struct hci_uart *hu = tty->disc_data;
498 	struct hci_dev *hdev;
499 	unsigned long flags;
500 
501 	BT_DBG("tty %p", tty);
502 
503 	/* Detach from the tty */
504 	tty->disc_data = NULL;
505 
506 	if (!hu)
507 		return;
508 
509 	hdev = hu->hdev;
510 	if (hdev)
511 		hci_uart_close(hdev);
512 
513 	cancel_work_sync(&hu->write_work);
514 
515 	if (test_bit(HCI_UART_PROTO_READY, &hu->flags)) {
516 		write_lock_irqsave(&hu->proto_lock, flags);
517 		clear_bit(HCI_UART_PROTO_READY, &hu->flags);
518 		write_unlock_irqrestore(&hu->proto_lock, flags);
519 
520 		if (hdev) {
521 			if (test_bit(HCI_UART_REGISTERED, &hu->flags))
522 				hci_unregister_dev(hdev);
523 			hci_free_dev(hdev);
524 		}
525 		hu->proto->close(hu);
526 	}
527 	clear_bit(HCI_UART_PROTO_SET, &hu->flags);
528 
529 	kfree(hu);
530 }
531 
532 /* hci_uart_tty_wakeup()
533  *
534  *    Callback for transmit wakeup. Called when low level
535  *    device driver can accept more send data.
536  *
537  * Arguments:        tty    pointer to associated tty instance data
538  * Return Value:    None
539  */
540 static void hci_uart_tty_wakeup(struct tty_struct *tty)
541 {
542 	struct hci_uart *hu = tty->disc_data;
543 
544 	BT_DBG("");
545 
546 	if (!hu)
547 		return;
548 
549 	clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
550 
551 	if (tty != hu->tty)
552 		return;
553 
554 	if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
555 		hci_uart_tx_wakeup(hu);
556 }
557 
558 /* hci_uart_tty_receive()
559  *
560  *     Called by tty low level driver when receive data is
561  *     available.
562  *
563  * Arguments:  tty          pointer to tty isntance data
564  *             data         pointer to received data
565  *             flags        pointer to flags for data
566  *             count        count of received data in bytes
567  *
568  * Return Value:    None
569  */
570 static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data,
571 				 char *flags, int count)
572 {
573 	struct hci_uart *hu = tty->disc_data;
574 
575 	if (!hu || tty != hu->tty)
576 		return;
577 
578 	read_lock(&hu->proto_lock);
579 
580 	if (!test_bit(HCI_UART_PROTO_READY, &hu->flags)) {
581 		read_unlock(&hu->proto_lock);
582 		return;
583 	}
584 
585 	/* It does not need a lock here as it is already protected by a mutex in
586 	 * tty caller
587 	 */
588 	hu->proto->recv(hu, data, count);
589 	read_unlock(&hu->proto_lock);
590 
591 	if (hu->hdev)
592 		hu->hdev->stat.byte_rx += count;
593 
594 	tty_unthrottle(tty);
595 }
596 
597 static int hci_uart_register_dev(struct hci_uart *hu)
598 {
599 	struct hci_dev *hdev;
600 
601 	BT_DBG("");
602 
603 	/* Initialize and register HCI device */
604 	hdev = hci_alloc_dev();
605 	if (!hdev) {
606 		BT_ERR("Can't allocate HCI device");
607 		return -ENOMEM;
608 	}
609 
610 	hu->hdev = hdev;
611 
612 	hdev->bus = HCI_UART;
613 	hci_set_drvdata(hdev, hu);
614 
615 	/* Only when vendor specific setup callback is provided, consider
616 	 * the manufacturer information valid. This avoids filling in the
617 	 * value for Ericsson when nothing is specified.
618 	 */
619 	if (hu->proto->setup)
620 		hdev->manufacturer = hu->proto->manufacturer;
621 
622 	hdev->open  = hci_uart_open;
623 	hdev->close = hci_uart_close;
624 	hdev->flush = hci_uart_flush;
625 	hdev->send  = hci_uart_send_frame;
626 	hdev->setup = hci_uart_setup;
627 	SET_HCIDEV_DEV(hdev, hu->tty->dev);
628 
629 	if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags))
630 		set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
631 
632 	if (test_bit(HCI_UART_EXT_CONFIG, &hu->hdev_flags))
633 		set_bit(HCI_QUIRK_EXTERNAL_CONFIG, &hdev->quirks);
634 
635 	if (!test_bit(HCI_UART_RESET_ON_INIT, &hu->hdev_flags))
636 		set_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks);
637 
638 	if (test_bit(HCI_UART_CREATE_AMP, &hu->hdev_flags))
639 		hdev->dev_type = HCI_AMP;
640 	else
641 		hdev->dev_type = HCI_PRIMARY;
642 
643 	if (test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
644 		return 0;
645 
646 	if (hci_register_dev(hdev) < 0) {
647 		BT_ERR("Can't register HCI device");
648 		hu->hdev = NULL;
649 		hci_free_dev(hdev);
650 		return -ENODEV;
651 	}
652 
653 	set_bit(HCI_UART_REGISTERED, &hu->flags);
654 
655 	return 0;
656 }
657 
658 static int hci_uart_set_proto(struct hci_uart *hu, int id)
659 {
660 	const struct hci_uart_proto *p;
661 	int err;
662 
663 	p = hci_uart_get_proto(id);
664 	if (!p)
665 		return -EPROTONOSUPPORT;
666 
667 	err = p->open(hu);
668 	if (err)
669 		return err;
670 
671 	hu->proto = p;
672 	set_bit(HCI_UART_PROTO_READY, &hu->flags);
673 
674 	err = hci_uart_register_dev(hu);
675 	if (err) {
676 		clear_bit(HCI_UART_PROTO_READY, &hu->flags);
677 		p->close(hu);
678 		return err;
679 	}
680 
681 	return 0;
682 }
683 
684 static int hci_uart_set_flags(struct hci_uart *hu, unsigned long flags)
685 {
686 	unsigned long valid_flags = BIT(HCI_UART_RAW_DEVICE) |
687 				    BIT(HCI_UART_RESET_ON_INIT) |
688 				    BIT(HCI_UART_CREATE_AMP) |
689 				    BIT(HCI_UART_INIT_PENDING) |
690 				    BIT(HCI_UART_EXT_CONFIG) |
691 				    BIT(HCI_UART_VND_DETECT);
692 
693 	if (flags & ~valid_flags)
694 		return -EINVAL;
695 
696 	hu->hdev_flags = flags;
697 
698 	return 0;
699 }
700 
701 /* hci_uart_tty_ioctl()
702  *
703  *    Process IOCTL system call for the tty device.
704  *
705  * Arguments:
706  *
707  *    tty        pointer to tty instance data
708  *    file       pointer to open file object for device
709  *    cmd        IOCTL command code
710  *    arg        argument for IOCTL call (cmd dependent)
711  *
712  * Return Value:    Command dependent
713  */
714 static int hci_uart_tty_ioctl(struct tty_struct *tty, struct file *file,
715 			      unsigned int cmd, unsigned long arg)
716 {
717 	struct hci_uart *hu = tty->disc_data;
718 	int err = 0;
719 
720 	BT_DBG("");
721 
722 	/* Verify the status of the device */
723 	if (!hu)
724 		return -EBADF;
725 
726 	switch (cmd) {
727 	case HCIUARTSETPROTO:
728 		if (!test_and_set_bit(HCI_UART_PROTO_SET, &hu->flags)) {
729 			err = hci_uart_set_proto(hu, arg);
730 			if (err)
731 				clear_bit(HCI_UART_PROTO_SET, &hu->flags);
732 		} else
733 			err = -EBUSY;
734 		break;
735 
736 	case HCIUARTGETPROTO:
737 		if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
738 			err = hu->proto->id;
739 		else
740 			err = -EUNATCH;
741 		break;
742 
743 	case HCIUARTGETDEVICE:
744 		if (test_bit(HCI_UART_REGISTERED, &hu->flags))
745 			err = hu->hdev->id;
746 		else
747 			err = -EUNATCH;
748 		break;
749 
750 	case HCIUARTSETFLAGS:
751 		if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
752 			err = -EBUSY;
753 		else
754 			err = hci_uart_set_flags(hu, arg);
755 		break;
756 
757 	case HCIUARTGETFLAGS:
758 		err = hu->hdev_flags;
759 		break;
760 
761 	default:
762 		err = n_tty_ioctl_helper(tty, file, cmd, arg);
763 		break;
764 	}
765 
766 	return err;
767 }
768 
769 /*
770  * We don't provide read/write/poll interface for user space.
771  */
772 static ssize_t hci_uart_tty_read(struct tty_struct *tty, struct file *file,
773 				 unsigned char __user *buf, size_t nr)
774 {
775 	return 0;
776 }
777 
778 static ssize_t hci_uart_tty_write(struct tty_struct *tty, struct file *file,
779 				  const unsigned char *data, size_t count)
780 {
781 	return 0;
782 }
783 
784 static unsigned int hci_uart_tty_poll(struct tty_struct *tty,
785 				      struct file *filp, poll_table *wait)
786 {
787 	return 0;
788 }
789 
790 static int __init hci_uart_init(void)
791 {
792 	static struct tty_ldisc_ops hci_uart_ldisc;
793 	int err;
794 
795 	BT_INFO("HCI UART driver ver %s", VERSION);
796 
797 	/* Register the tty discipline */
798 
799 	memset(&hci_uart_ldisc, 0, sizeof(hci_uart_ldisc));
800 	hci_uart_ldisc.magic		= TTY_LDISC_MAGIC;
801 	hci_uart_ldisc.name		= "n_hci";
802 	hci_uart_ldisc.open		= hci_uart_tty_open;
803 	hci_uart_ldisc.close		= hci_uart_tty_close;
804 	hci_uart_ldisc.read		= hci_uart_tty_read;
805 	hci_uart_ldisc.write		= hci_uart_tty_write;
806 	hci_uart_ldisc.ioctl		= hci_uart_tty_ioctl;
807 	hci_uart_ldisc.poll		= hci_uart_tty_poll;
808 	hci_uart_ldisc.receive_buf	= hci_uart_tty_receive;
809 	hci_uart_ldisc.write_wakeup	= hci_uart_tty_wakeup;
810 	hci_uart_ldisc.owner		= THIS_MODULE;
811 
812 	err = tty_register_ldisc(N_HCI, &hci_uart_ldisc);
813 	if (err) {
814 		BT_ERR("HCI line discipline registration failed. (%d)", err);
815 		return err;
816 	}
817 
818 #ifdef CONFIG_BT_HCIUART_H4
819 	h4_init();
820 #endif
821 #ifdef CONFIG_BT_HCIUART_BCSP
822 	bcsp_init();
823 #endif
824 #ifdef CONFIG_BT_HCIUART_LL
825 	ll_init();
826 #endif
827 #ifdef CONFIG_BT_HCIUART_ATH3K
828 	ath_init();
829 #endif
830 #ifdef CONFIG_BT_HCIUART_3WIRE
831 	h5_init();
832 #endif
833 #ifdef CONFIG_BT_HCIUART_INTEL
834 	intel_init();
835 #endif
836 #ifdef CONFIG_BT_HCIUART_BCM
837 	bcm_init();
838 #endif
839 #ifdef CONFIG_BT_HCIUART_QCA
840 	qca_init();
841 #endif
842 #ifdef CONFIG_BT_HCIUART_AG6XX
843 	ag6xx_init();
844 #endif
845 #ifdef CONFIG_BT_HCIUART_MRVL
846 	mrvl_init();
847 #endif
848 
849 	return 0;
850 }
851 
852 static void __exit hci_uart_exit(void)
853 {
854 	int err;
855 
856 #ifdef CONFIG_BT_HCIUART_H4
857 	h4_deinit();
858 #endif
859 #ifdef CONFIG_BT_HCIUART_BCSP
860 	bcsp_deinit();
861 #endif
862 #ifdef CONFIG_BT_HCIUART_LL
863 	ll_deinit();
864 #endif
865 #ifdef CONFIG_BT_HCIUART_ATH3K
866 	ath_deinit();
867 #endif
868 #ifdef CONFIG_BT_HCIUART_3WIRE
869 	h5_deinit();
870 #endif
871 #ifdef CONFIG_BT_HCIUART_INTEL
872 	intel_deinit();
873 #endif
874 #ifdef CONFIG_BT_HCIUART_BCM
875 	bcm_deinit();
876 #endif
877 #ifdef CONFIG_BT_HCIUART_QCA
878 	qca_deinit();
879 #endif
880 #ifdef CONFIG_BT_HCIUART_AG6XX
881 	ag6xx_deinit();
882 #endif
883 #ifdef CONFIG_BT_HCIUART_MRVL
884 	mrvl_deinit();
885 #endif
886 
887 	/* Release tty registration of line discipline */
888 	err = tty_unregister_ldisc(N_HCI);
889 	if (err)
890 		BT_ERR("Can't unregister HCI line discipline (%d)", err);
891 }
892 
893 module_init(hci_uart_init);
894 module_exit(hci_uart_exit);
895 
896 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
897 MODULE_DESCRIPTION("Bluetooth HCI UART driver ver " VERSION);
898 MODULE_VERSION(VERSION);
899 MODULE_LICENSE("GPL");
900 MODULE_ALIAS_LDISC(N_HCI);
901