xref: /openbmc/linux/drivers/bluetooth/hci_ldisc.c (revision 7aacf86b)
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 	if (tty->ops->write == NULL)
462 		return -EOPNOTSUPP;
463 
464 	hu = kzalloc(sizeof(struct hci_uart), GFP_KERNEL);
465 	if (!hu) {
466 		BT_ERR("Can't allocate control structure");
467 		return -ENFILE;
468 	}
469 
470 	tty->disc_data = hu;
471 	hu->tty = tty;
472 	tty->receive_room = 65536;
473 
474 	/* disable alignment support by default */
475 	hu->alignment = 1;
476 	hu->padding = 0;
477 
478 	INIT_WORK(&hu->init_ready, hci_uart_init_work);
479 	INIT_WORK(&hu->write_work, hci_uart_write_work);
480 
481 	rwlock_init(&hu->proto_lock);
482 
483 	/* Flush any pending characters in the driver */
484 	tty_driver_flush_buffer(tty);
485 
486 	return 0;
487 }
488 
489 /* hci_uart_tty_close()
490  *
491  *    Called when the line discipline is changed to something
492  *    else, the tty is closed, or the tty detects a hangup.
493  */
494 static void hci_uart_tty_close(struct tty_struct *tty)
495 {
496 	struct hci_uart *hu = tty->disc_data;
497 	struct hci_dev *hdev;
498 	unsigned long flags;
499 
500 	BT_DBG("tty %p", tty);
501 
502 	/* Detach from the tty */
503 	tty->disc_data = NULL;
504 
505 	if (!hu)
506 		return;
507 
508 	hdev = hu->hdev;
509 	if (hdev)
510 		hci_uart_close(hdev);
511 
512 	cancel_work_sync(&hu->write_work);
513 
514 	if (test_bit(HCI_UART_PROTO_READY, &hu->flags)) {
515 		write_lock_irqsave(&hu->proto_lock, flags);
516 		clear_bit(HCI_UART_PROTO_READY, &hu->flags);
517 		write_unlock_irqrestore(&hu->proto_lock, flags);
518 
519 		if (hdev) {
520 			if (test_bit(HCI_UART_REGISTERED, &hu->flags))
521 				hci_unregister_dev(hdev);
522 			hci_free_dev(hdev);
523 		}
524 		hu->proto->close(hu);
525 	}
526 	clear_bit(HCI_UART_PROTO_SET, &hu->flags);
527 
528 	kfree(hu);
529 }
530 
531 /* hci_uart_tty_wakeup()
532  *
533  *    Callback for transmit wakeup. Called when low level
534  *    device driver can accept more send data.
535  *
536  * Arguments:        tty    pointer to associated tty instance data
537  * Return Value:    None
538  */
539 static void hci_uart_tty_wakeup(struct tty_struct *tty)
540 {
541 	struct hci_uart *hu = tty->disc_data;
542 
543 	BT_DBG("");
544 
545 	if (!hu)
546 		return;
547 
548 	clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
549 
550 	if (tty != hu->tty)
551 		return;
552 
553 	if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
554 		hci_uart_tx_wakeup(hu);
555 }
556 
557 /* hci_uart_tty_receive()
558  *
559  *     Called by tty low level driver when receive data is
560  *     available.
561  *
562  * Arguments:  tty          pointer to tty isntance data
563  *             data         pointer to received data
564  *             flags        pointer to flags for data
565  *             count        count of received data in bytes
566  *
567  * Return Value:    None
568  */
569 static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data,
570 				 char *flags, int count)
571 {
572 	struct hci_uart *hu = tty->disc_data;
573 
574 	if (!hu || tty != hu->tty)
575 		return;
576 
577 	read_lock(&hu->proto_lock);
578 
579 	if (!test_bit(HCI_UART_PROTO_READY, &hu->flags)) {
580 		read_unlock(&hu->proto_lock);
581 		return;
582 	}
583 
584 	/* It does not need a lock here as it is already protected by a mutex in
585 	 * tty caller
586 	 */
587 	hu->proto->recv(hu, data, count);
588 	read_unlock(&hu->proto_lock);
589 
590 	if (hu->hdev)
591 		hu->hdev->stat.byte_rx += count;
592 
593 	tty_unthrottle(tty);
594 }
595 
596 static int hci_uart_register_dev(struct hci_uart *hu)
597 {
598 	struct hci_dev *hdev;
599 
600 	BT_DBG("");
601 
602 	/* Initialize and register HCI device */
603 	hdev = hci_alloc_dev();
604 	if (!hdev) {
605 		BT_ERR("Can't allocate HCI device");
606 		return -ENOMEM;
607 	}
608 
609 	hu->hdev = hdev;
610 
611 	hdev->bus = HCI_UART;
612 	hci_set_drvdata(hdev, hu);
613 
614 	/* Only when vendor specific setup callback is provided, consider
615 	 * the manufacturer information valid. This avoids filling in the
616 	 * value for Ericsson when nothing is specified.
617 	 */
618 	if (hu->proto->setup)
619 		hdev->manufacturer = hu->proto->manufacturer;
620 
621 	hdev->open  = hci_uart_open;
622 	hdev->close = hci_uart_close;
623 	hdev->flush = hci_uart_flush;
624 	hdev->send  = hci_uart_send_frame;
625 	hdev->setup = hci_uart_setup;
626 	SET_HCIDEV_DEV(hdev, hu->tty->dev);
627 
628 	if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags))
629 		set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
630 
631 	if (test_bit(HCI_UART_EXT_CONFIG, &hu->hdev_flags))
632 		set_bit(HCI_QUIRK_EXTERNAL_CONFIG, &hdev->quirks);
633 
634 	if (!test_bit(HCI_UART_RESET_ON_INIT, &hu->hdev_flags))
635 		set_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks);
636 
637 	if (test_bit(HCI_UART_CREATE_AMP, &hu->hdev_flags))
638 		hdev->dev_type = HCI_AMP;
639 	else
640 		hdev->dev_type = HCI_PRIMARY;
641 
642 	if (test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
643 		return 0;
644 
645 	if (hci_register_dev(hdev) < 0) {
646 		BT_ERR("Can't register HCI device");
647 		hu->hdev = NULL;
648 		hci_free_dev(hdev);
649 		return -ENODEV;
650 	}
651 
652 	set_bit(HCI_UART_REGISTERED, &hu->flags);
653 
654 	return 0;
655 }
656 
657 static int hci_uart_set_proto(struct hci_uart *hu, int id)
658 {
659 	const struct hci_uart_proto *p;
660 	int err;
661 
662 	p = hci_uart_get_proto(id);
663 	if (!p)
664 		return -EPROTONOSUPPORT;
665 
666 	err = p->open(hu);
667 	if (err)
668 		return err;
669 
670 	hu->proto = p;
671 	set_bit(HCI_UART_PROTO_READY, &hu->flags);
672 
673 	err = hci_uart_register_dev(hu);
674 	if (err) {
675 		clear_bit(HCI_UART_PROTO_READY, &hu->flags);
676 		p->close(hu);
677 		return err;
678 	}
679 
680 	return 0;
681 }
682 
683 static int hci_uart_set_flags(struct hci_uart *hu, unsigned long flags)
684 {
685 	unsigned long valid_flags = BIT(HCI_UART_RAW_DEVICE) |
686 				    BIT(HCI_UART_RESET_ON_INIT) |
687 				    BIT(HCI_UART_CREATE_AMP) |
688 				    BIT(HCI_UART_INIT_PENDING) |
689 				    BIT(HCI_UART_EXT_CONFIG) |
690 				    BIT(HCI_UART_VND_DETECT);
691 
692 	if (flags & ~valid_flags)
693 		return -EINVAL;
694 
695 	hu->hdev_flags = flags;
696 
697 	return 0;
698 }
699 
700 /* hci_uart_tty_ioctl()
701  *
702  *    Process IOCTL system call for the tty device.
703  *
704  * Arguments:
705  *
706  *    tty        pointer to tty instance data
707  *    file       pointer to open file object for device
708  *    cmd        IOCTL command code
709  *    arg        argument for IOCTL call (cmd dependent)
710  *
711  * Return Value:    Command dependent
712  */
713 static int hci_uart_tty_ioctl(struct tty_struct *tty, struct file *file,
714 			      unsigned int cmd, unsigned long arg)
715 {
716 	struct hci_uart *hu = tty->disc_data;
717 	int err = 0;
718 
719 	BT_DBG("");
720 
721 	/* Verify the status of the device */
722 	if (!hu)
723 		return -EBADF;
724 
725 	switch (cmd) {
726 	case HCIUARTSETPROTO:
727 		if (!test_and_set_bit(HCI_UART_PROTO_SET, &hu->flags)) {
728 			err = hci_uart_set_proto(hu, arg);
729 			if (err)
730 				clear_bit(HCI_UART_PROTO_SET, &hu->flags);
731 		} else
732 			err = -EBUSY;
733 		break;
734 
735 	case HCIUARTGETPROTO:
736 		if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
737 			err = hu->proto->id;
738 		else
739 			err = -EUNATCH;
740 		break;
741 
742 	case HCIUARTGETDEVICE:
743 		if (test_bit(HCI_UART_REGISTERED, &hu->flags))
744 			err = hu->hdev->id;
745 		else
746 			err = -EUNATCH;
747 		break;
748 
749 	case HCIUARTSETFLAGS:
750 		if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
751 			err = -EBUSY;
752 		else
753 			err = hci_uart_set_flags(hu, arg);
754 		break;
755 
756 	case HCIUARTGETFLAGS:
757 		err = hu->hdev_flags;
758 		break;
759 
760 	default:
761 		err = n_tty_ioctl_helper(tty, file, cmd, arg);
762 		break;
763 	}
764 
765 	return err;
766 }
767 
768 /*
769  * We don't provide read/write/poll interface for user space.
770  */
771 static ssize_t hci_uart_tty_read(struct tty_struct *tty, struct file *file,
772 				 unsigned char __user *buf, size_t nr)
773 {
774 	return 0;
775 }
776 
777 static ssize_t hci_uart_tty_write(struct tty_struct *tty, struct file *file,
778 				  const unsigned char *data, size_t count)
779 {
780 	return 0;
781 }
782 
783 static unsigned int hci_uart_tty_poll(struct tty_struct *tty,
784 				      struct file *filp, poll_table *wait)
785 {
786 	return 0;
787 }
788 
789 static int __init hci_uart_init(void)
790 {
791 	static struct tty_ldisc_ops hci_uart_ldisc;
792 	int err;
793 
794 	BT_INFO("HCI UART driver ver %s", VERSION);
795 
796 	/* Register the tty discipline */
797 
798 	memset(&hci_uart_ldisc, 0, sizeof(hci_uart_ldisc));
799 	hci_uart_ldisc.magic		= TTY_LDISC_MAGIC;
800 	hci_uart_ldisc.name		= "n_hci";
801 	hci_uart_ldisc.open		= hci_uart_tty_open;
802 	hci_uart_ldisc.close		= hci_uart_tty_close;
803 	hci_uart_ldisc.read		= hci_uart_tty_read;
804 	hci_uart_ldisc.write		= hci_uart_tty_write;
805 	hci_uart_ldisc.ioctl		= hci_uart_tty_ioctl;
806 	hci_uart_ldisc.poll		= hci_uart_tty_poll;
807 	hci_uart_ldisc.receive_buf	= hci_uart_tty_receive;
808 	hci_uart_ldisc.write_wakeup	= hci_uart_tty_wakeup;
809 	hci_uart_ldisc.owner		= THIS_MODULE;
810 
811 	err = tty_register_ldisc(N_HCI, &hci_uart_ldisc);
812 	if (err) {
813 		BT_ERR("HCI line discipline registration failed. (%d)", err);
814 		return err;
815 	}
816 
817 #ifdef CONFIG_BT_HCIUART_H4
818 	h4_init();
819 #endif
820 #ifdef CONFIG_BT_HCIUART_BCSP
821 	bcsp_init();
822 #endif
823 #ifdef CONFIG_BT_HCIUART_LL
824 	ll_init();
825 #endif
826 #ifdef CONFIG_BT_HCIUART_ATH3K
827 	ath_init();
828 #endif
829 #ifdef CONFIG_BT_HCIUART_3WIRE
830 	h5_init();
831 #endif
832 #ifdef CONFIG_BT_HCIUART_INTEL
833 	intel_init();
834 #endif
835 #ifdef CONFIG_BT_HCIUART_BCM
836 	bcm_init();
837 #endif
838 #ifdef CONFIG_BT_HCIUART_QCA
839 	qca_init();
840 #endif
841 #ifdef CONFIG_BT_HCIUART_AG6XX
842 	ag6xx_init();
843 #endif
844 #ifdef CONFIG_BT_HCIUART_MRVL
845 	mrvl_init();
846 #endif
847 
848 	return 0;
849 }
850 
851 static void __exit hci_uart_exit(void)
852 {
853 	int err;
854 
855 #ifdef CONFIG_BT_HCIUART_H4
856 	h4_deinit();
857 #endif
858 #ifdef CONFIG_BT_HCIUART_BCSP
859 	bcsp_deinit();
860 #endif
861 #ifdef CONFIG_BT_HCIUART_LL
862 	ll_deinit();
863 #endif
864 #ifdef CONFIG_BT_HCIUART_ATH3K
865 	ath_deinit();
866 #endif
867 #ifdef CONFIG_BT_HCIUART_3WIRE
868 	h5_deinit();
869 #endif
870 #ifdef CONFIG_BT_HCIUART_INTEL
871 	intel_deinit();
872 #endif
873 #ifdef CONFIG_BT_HCIUART_BCM
874 	bcm_deinit();
875 #endif
876 #ifdef CONFIG_BT_HCIUART_QCA
877 	qca_deinit();
878 #endif
879 #ifdef CONFIG_BT_HCIUART_AG6XX
880 	ag6xx_deinit();
881 #endif
882 #ifdef CONFIG_BT_HCIUART_MRVL
883 	mrvl_deinit();
884 #endif
885 
886 	/* Release tty registration of line discipline */
887 	err = tty_unregister_ldisc(N_HCI);
888 	if (err)
889 		BT_ERR("Can't unregister HCI line discipline (%d)", err);
890 }
891 
892 module_init(hci_uart_init);
893 module_exit(hci_uart_exit);
894 
895 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
896 MODULE_DESCRIPTION("Bluetooth HCI UART driver ver " VERSION);
897 MODULE_VERSION(VERSION);
898 MODULE_LICENSE("GPL");
899 MODULE_ALIAS_LDISC(N_HCI);
900