xref: /openbmc/linux/drivers/bluetooth/hci_ldisc.c (revision eb3fcf00)
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 		skb = hu->proto->dequeue(hu);
118 	else
119 		hu->tx_skb = NULL;
120 
121 	return skb;
122 }
123 
124 int hci_uart_tx_wakeup(struct hci_uart *hu)
125 {
126 	if (test_and_set_bit(HCI_UART_SENDING, &hu->tx_state)) {
127 		set_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
128 		return 0;
129 	}
130 
131 	BT_DBG("");
132 
133 	schedule_work(&hu->write_work);
134 
135 	return 0;
136 }
137 
138 static void hci_uart_write_work(struct work_struct *work)
139 {
140 	struct hci_uart *hu = container_of(work, struct hci_uart, write_work);
141 	struct tty_struct *tty = hu->tty;
142 	struct hci_dev *hdev = hu->hdev;
143 	struct sk_buff *skb;
144 
145 	/* REVISIT: should we cope with bad skbs or ->write() returning
146 	 * and error value ?
147 	 */
148 
149 restart:
150 	clear_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
151 
152 	while ((skb = hci_uart_dequeue(hu))) {
153 		int len;
154 
155 		set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
156 		len = tty->ops->write(tty, skb->data, skb->len);
157 		hdev->stat.byte_tx += len;
158 
159 		skb_pull(skb, len);
160 		if (skb->len) {
161 			hu->tx_skb = skb;
162 			break;
163 		}
164 
165 		hci_uart_tx_complete(hu, bt_cb(skb)->pkt_type);
166 		kfree_skb(skb);
167 	}
168 
169 	if (test_bit(HCI_UART_TX_WAKEUP, &hu->tx_state))
170 		goto restart;
171 
172 	clear_bit(HCI_UART_SENDING, &hu->tx_state);
173 }
174 
175 static void hci_uart_init_work(struct work_struct *work)
176 {
177 	struct hci_uart *hu = container_of(work, struct hci_uart, init_ready);
178 	int err;
179 
180 	if (!test_and_clear_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
181 		return;
182 
183 	err = hci_register_dev(hu->hdev);
184 	if (err < 0) {
185 		BT_ERR("Can't register HCI device");
186 		hci_free_dev(hu->hdev);
187 		hu->hdev = NULL;
188 		hu->proto->close(hu);
189 	}
190 
191 	set_bit(HCI_UART_REGISTERED, &hu->flags);
192 }
193 
194 int hci_uart_init_ready(struct hci_uart *hu)
195 {
196 	if (!test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
197 		return -EALREADY;
198 
199 	schedule_work(&hu->init_ready);
200 
201 	return 0;
202 }
203 
204 /* ------- Interface to HCI layer ------ */
205 /* Initialize device */
206 static int hci_uart_open(struct hci_dev *hdev)
207 {
208 	BT_DBG("%s %p", hdev->name, hdev);
209 
210 	/* Nothing to do for UART driver */
211 
212 	set_bit(HCI_RUNNING, &hdev->flags);
213 
214 	return 0;
215 }
216 
217 /* Reset device */
218 static int hci_uart_flush(struct hci_dev *hdev)
219 {
220 	struct hci_uart *hu  = hci_get_drvdata(hdev);
221 	struct tty_struct *tty = hu->tty;
222 
223 	BT_DBG("hdev %p tty %p", hdev, tty);
224 
225 	if (hu->tx_skb) {
226 		kfree_skb(hu->tx_skb); hu->tx_skb = NULL;
227 	}
228 
229 	/* Flush any pending characters in the driver and discipline. */
230 	tty_ldisc_flush(tty);
231 	tty_driver_flush_buffer(tty);
232 
233 	if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
234 		hu->proto->flush(hu);
235 
236 	return 0;
237 }
238 
239 /* Close device */
240 static int hci_uart_close(struct hci_dev *hdev)
241 {
242 	BT_DBG("hdev %p", hdev);
243 
244 	if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags))
245 		return 0;
246 
247 	hci_uart_flush(hdev);
248 	hdev->flush = NULL;
249 	return 0;
250 }
251 
252 /* Send frames from HCI layer */
253 static int hci_uart_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
254 {
255 	struct hci_uart *hu = hci_get_drvdata(hdev);
256 
257 	if (!test_bit(HCI_RUNNING, &hdev->flags))
258 		return -EBUSY;
259 
260 	BT_DBG("%s: type %d len %d", hdev->name, bt_cb(skb)->pkt_type, skb->len);
261 
262 	hu->proto->enqueue(hu, skb);
263 
264 	hci_uart_tx_wakeup(hu);
265 
266 	return 0;
267 }
268 
269 /* Flow control or un-flow control the device */
270 void hci_uart_set_flow_control(struct hci_uart *hu, bool enable)
271 {
272 	struct tty_struct *tty = hu->tty;
273 	struct ktermios ktermios;
274 	int status;
275 	unsigned int set = 0;
276 	unsigned int clear = 0;
277 
278 	if (enable) {
279 		/* Disable hardware flow control */
280 		ktermios = tty->termios;
281 		ktermios.c_cflag &= ~CRTSCTS;
282 		status = tty_set_termios(tty, &ktermios);
283 		BT_DBG("Disabling hardware flow control: %s",
284 		       status ? "failed" : "success");
285 
286 		/* Clear RTS to prevent the device from sending */
287 		/* Most UARTs need OUT2 to enable interrupts */
288 		status = tty->driver->ops->tiocmget(tty);
289 		BT_DBG("Current tiocm 0x%x", status);
290 
291 		set &= ~(TIOCM_OUT2 | TIOCM_RTS);
292 		clear = ~set;
293 		set &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
294 		       TIOCM_OUT2 | TIOCM_LOOP;
295 		clear &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
296 			 TIOCM_OUT2 | TIOCM_LOOP;
297 		status = tty->driver->ops->tiocmset(tty, set, clear);
298 		BT_DBG("Clearing RTS: %s", status ? "failed" : "success");
299 	} else {
300 		/* Set RTS to allow the device to send again */
301 		status = tty->driver->ops->tiocmget(tty);
302 		BT_DBG("Current tiocm 0x%x", status);
303 
304 		set |= (TIOCM_OUT2 | TIOCM_RTS);
305 		clear = ~set;
306 		set &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
307 		       TIOCM_OUT2 | TIOCM_LOOP;
308 		clear &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
309 			 TIOCM_OUT2 | TIOCM_LOOP;
310 		status = tty->driver->ops->tiocmset(tty, set, clear);
311 		BT_DBG("Setting RTS: %s", status ? "failed" : "success");
312 
313 		/* Re-enable hardware flow control */
314 		ktermios = tty->termios;
315 		ktermios.c_cflag |= CRTSCTS;
316 		status = tty_set_termios(tty, &ktermios);
317 		BT_DBG("Enabling hardware flow control: %s",
318 		       status ? "failed" : "success");
319 	}
320 }
321 
322 void hci_uart_set_speeds(struct hci_uart *hu, unsigned int init_speed,
323 			 unsigned int oper_speed)
324 {
325 	hu->init_speed = init_speed;
326 	hu->oper_speed = oper_speed;
327 }
328 
329 void hci_uart_init_tty(struct hci_uart *hu)
330 {
331 	struct tty_struct *tty = hu->tty;
332 	struct ktermios ktermios;
333 
334 	/* Bring the UART into a known 8 bits no parity hw fc state */
335 	ktermios = tty->termios;
336 	ktermios.c_iflag &= ~(IGNBRK | BRKINT | PARMRK | ISTRIP |
337 			      INLCR | IGNCR | ICRNL | IXON);
338 	ktermios.c_oflag &= ~OPOST;
339 	ktermios.c_lflag &= ~(ECHO | ECHONL | ICANON | ISIG | IEXTEN);
340 	ktermios.c_cflag &= ~(CSIZE | PARENB);
341 	ktermios.c_cflag |= CS8;
342 	ktermios.c_cflag |= CRTSCTS;
343 
344 	/* tty_set_termios() return not checked as it is always 0 */
345 	tty_set_termios(tty, &ktermios);
346 }
347 
348 void hci_uart_set_baudrate(struct hci_uart *hu, unsigned int speed)
349 {
350 	struct tty_struct *tty = hu->tty;
351 	struct ktermios ktermios;
352 
353 	ktermios = tty->termios;
354 	ktermios.c_cflag &= ~CBAUD;
355 	tty_termios_encode_baud_rate(&ktermios, speed, speed);
356 
357 	/* tty_set_termios() return not checked as it is always 0 */
358 	tty_set_termios(tty, &ktermios);
359 
360 	BT_DBG("%s: New tty speeds: %d/%d", hu->hdev->name,
361 	       tty->termios.c_ispeed, tty->termios.c_ospeed);
362 }
363 
364 static int hci_uart_setup(struct hci_dev *hdev)
365 {
366 	struct hci_uart *hu = hci_get_drvdata(hdev);
367 	struct hci_rp_read_local_version *ver;
368 	struct sk_buff *skb;
369 	unsigned int speed;
370 	int err;
371 
372 	/* Init speed if any */
373 	if (hu->init_speed)
374 		speed = hu->init_speed;
375 	else if (hu->proto->init_speed)
376 		speed = hu->proto->init_speed;
377 	else
378 		speed = 0;
379 
380 	if (speed)
381 		hci_uart_set_baudrate(hu, speed);
382 
383 	/* Operational speed if any */
384 	if (hu->oper_speed)
385 		speed = hu->oper_speed;
386 	else if (hu->proto->oper_speed)
387 		speed = hu->proto->oper_speed;
388 	else
389 		speed = 0;
390 
391 	if (hu->proto->set_baudrate && speed) {
392 		err = hu->proto->set_baudrate(hu, speed);
393 		if (!err)
394 			hci_uart_set_baudrate(hu, speed);
395 	}
396 
397 	if (hu->proto->setup)
398 		return hu->proto->setup(hu);
399 
400 	if (!test_bit(HCI_UART_VND_DETECT, &hu->hdev_flags))
401 		return 0;
402 
403 	skb = __hci_cmd_sync(hdev, HCI_OP_READ_LOCAL_VERSION, 0, NULL,
404 			     HCI_INIT_TIMEOUT);
405 	if (IS_ERR(skb)) {
406 		BT_ERR("%s: Reading local version information failed (%ld)",
407 		       hdev->name, PTR_ERR(skb));
408 		return 0;
409 	}
410 
411 	if (skb->len != sizeof(*ver)) {
412 		BT_ERR("%s: Event length mismatch for version information",
413 		       hdev->name);
414 		goto done;
415 	}
416 
417 	ver = (struct hci_rp_read_local_version *)skb->data;
418 
419 	switch (le16_to_cpu(ver->manufacturer)) {
420 #ifdef CONFIG_BT_HCIUART_INTEL
421 	case 2:
422 		hdev->set_bdaddr = btintel_set_bdaddr;
423 		btintel_check_bdaddr(hdev);
424 		break;
425 #endif
426 #ifdef CONFIG_BT_HCIUART_BCM
427 	case 15:
428 		hdev->set_bdaddr = btbcm_set_bdaddr;
429 		btbcm_check_bdaddr(hdev);
430 		break;
431 #endif
432 	}
433 
434 done:
435 	kfree_skb(skb);
436 	return 0;
437 }
438 
439 /* ------ LDISC part ------ */
440 /* hci_uart_tty_open
441  *
442  *     Called when line discipline changed to HCI_UART.
443  *
444  * Arguments:
445  *     tty    pointer to tty info structure
446  * Return Value:
447  *     0 if success, otherwise error code
448  */
449 static int hci_uart_tty_open(struct tty_struct *tty)
450 {
451 	struct hci_uart *hu;
452 
453 	BT_DBG("tty %p", tty);
454 
455 	/* Error if the tty has no write op instead of leaving an exploitable
456 	   hole */
457 	if (tty->ops->write == NULL)
458 		return -EOPNOTSUPP;
459 
460 	hu = kzalloc(sizeof(struct hci_uart), GFP_KERNEL);
461 	if (!hu) {
462 		BT_ERR("Can't allocate control structure");
463 		return -ENFILE;
464 	}
465 
466 	tty->disc_data = hu;
467 	hu->tty = tty;
468 	tty->receive_room = 65536;
469 
470 	INIT_WORK(&hu->init_ready, hci_uart_init_work);
471 	INIT_WORK(&hu->write_work, hci_uart_write_work);
472 
473 	spin_lock_init(&hu->rx_lock);
474 
475 	/* Flush any pending characters in the driver and line discipline. */
476 
477 	/* FIXME: why is this needed. Note don't use ldisc_ref here as the
478 	   open path is before the ldisc is referencable */
479 
480 	if (tty->ldisc->ops->flush_buffer)
481 		tty->ldisc->ops->flush_buffer(tty);
482 	tty_driver_flush_buffer(tty);
483 
484 	return 0;
485 }
486 
487 /* hci_uart_tty_close()
488  *
489  *    Called when the line discipline is changed to something
490  *    else, the tty is closed, or the tty detects a hangup.
491  */
492 static void hci_uart_tty_close(struct tty_struct *tty)
493 {
494 	struct hci_uart *hu = tty->disc_data;
495 	struct hci_dev *hdev;
496 
497 	BT_DBG("tty %p", tty);
498 
499 	/* Detach from the tty */
500 	tty->disc_data = NULL;
501 
502 	if (!hu)
503 		return;
504 
505 	hdev = hu->hdev;
506 	if (hdev)
507 		hci_uart_close(hdev);
508 
509 	cancel_work_sync(&hu->write_work);
510 
511 	if (test_and_clear_bit(HCI_UART_PROTO_SET, &hu->flags)) {
512 		if (hdev) {
513 			if (test_bit(HCI_UART_REGISTERED, &hu->flags))
514 				hci_unregister_dev(hdev);
515 			hci_free_dev(hdev);
516 		}
517 		hu->proto->close(hu);
518 	}
519 
520 	kfree(hu);
521 }
522 
523 /* hci_uart_tty_wakeup()
524  *
525  *    Callback for transmit wakeup. Called when low level
526  *    device driver can accept more send data.
527  *
528  * Arguments:        tty    pointer to associated tty instance data
529  * Return Value:    None
530  */
531 static void hci_uart_tty_wakeup(struct tty_struct *tty)
532 {
533 	struct hci_uart *hu = tty->disc_data;
534 
535 	BT_DBG("");
536 
537 	if (!hu)
538 		return;
539 
540 	clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
541 
542 	if (tty != hu->tty)
543 		return;
544 
545 	if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
546 		hci_uart_tx_wakeup(hu);
547 }
548 
549 /* hci_uart_tty_receive()
550  *
551  *     Called by tty low level driver when receive data is
552  *     available.
553  *
554  * Arguments:  tty          pointer to tty isntance data
555  *             data         pointer to received data
556  *             flags        pointer to flags for data
557  *             count        count of received data in bytes
558  *
559  * Return Value:    None
560  */
561 static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data,
562 				 char *flags, int count)
563 {
564 	struct hci_uart *hu = tty->disc_data;
565 
566 	if (!hu || tty != hu->tty)
567 		return;
568 
569 	if (!test_bit(HCI_UART_PROTO_SET, &hu->flags))
570 		return;
571 
572 	spin_lock(&hu->rx_lock);
573 	hu->proto->recv(hu, data, count);
574 
575 	if (hu->hdev)
576 		hu->hdev->stat.byte_rx += count;
577 
578 	spin_unlock(&hu->rx_lock);
579 
580 	tty_unthrottle(tty);
581 }
582 
583 static int hci_uart_register_dev(struct hci_uart *hu)
584 {
585 	struct hci_dev *hdev;
586 
587 	BT_DBG("");
588 
589 	/* Initialize and register HCI device */
590 	hdev = hci_alloc_dev();
591 	if (!hdev) {
592 		BT_ERR("Can't allocate HCI device");
593 		return -ENOMEM;
594 	}
595 
596 	hu->hdev = hdev;
597 
598 	hdev->bus = HCI_UART;
599 	hci_set_drvdata(hdev, hu);
600 
601 	hdev->open  = hci_uart_open;
602 	hdev->close = hci_uart_close;
603 	hdev->flush = hci_uart_flush;
604 	hdev->send  = hci_uart_send_frame;
605 	hdev->setup = hci_uart_setup;
606 	SET_HCIDEV_DEV(hdev, hu->tty->dev);
607 
608 	if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags))
609 		set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
610 
611 	if (test_bit(HCI_UART_EXT_CONFIG, &hu->hdev_flags))
612 		set_bit(HCI_QUIRK_EXTERNAL_CONFIG, &hdev->quirks);
613 
614 	if (!test_bit(HCI_UART_RESET_ON_INIT, &hu->hdev_flags))
615 		set_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks);
616 
617 	if (test_bit(HCI_UART_CREATE_AMP, &hu->hdev_flags))
618 		hdev->dev_type = HCI_AMP;
619 	else
620 		hdev->dev_type = HCI_BREDR;
621 
622 	if (test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
623 		return 0;
624 
625 	if (hci_register_dev(hdev) < 0) {
626 		BT_ERR("Can't register HCI device");
627 		hci_free_dev(hdev);
628 		return -ENODEV;
629 	}
630 
631 	set_bit(HCI_UART_REGISTERED, &hu->flags);
632 
633 	return 0;
634 }
635 
636 static int hci_uart_set_proto(struct hci_uart *hu, int id)
637 {
638 	const struct hci_uart_proto *p;
639 	int err;
640 
641 	p = hci_uart_get_proto(id);
642 	if (!p)
643 		return -EPROTONOSUPPORT;
644 
645 	err = p->open(hu);
646 	if (err)
647 		return err;
648 
649 	hu->proto = p;
650 
651 	err = hci_uart_register_dev(hu);
652 	if (err) {
653 		p->close(hu);
654 		return err;
655 	}
656 
657 	return 0;
658 }
659 
660 static int hci_uart_set_flags(struct hci_uart *hu, unsigned long flags)
661 {
662 	unsigned long valid_flags = BIT(HCI_UART_RAW_DEVICE) |
663 				    BIT(HCI_UART_RESET_ON_INIT) |
664 				    BIT(HCI_UART_CREATE_AMP) |
665 				    BIT(HCI_UART_INIT_PENDING) |
666 				    BIT(HCI_UART_EXT_CONFIG) |
667 				    BIT(HCI_UART_VND_DETECT);
668 
669 	if (flags & ~valid_flags)
670 		return -EINVAL;
671 
672 	hu->hdev_flags = flags;
673 
674 	return 0;
675 }
676 
677 /* hci_uart_tty_ioctl()
678  *
679  *    Process IOCTL system call for the tty device.
680  *
681  * Arguments:
682  *
683  *    tty        pointer to tty instance data
684  *    file       pointer to open file object for device
685  *    cmd        IOCTL command code
686  *    arg        argument for IOCTL call (cmd dependent)
687  *
688  * Return Value:    Command dependent
689  */
690 static int hci_uart_tty_ioctl(struct tty_struct *tty, struct file *file,
691 			      unsigned int cmd, unsigned long arg)
692 {
693 	struct hci_uart *hu = tty->disc_data;
694 	int err = 0;
695 
696 	BT_DBG("");
697 
698 	/* Verify the status of the device */
699 	if (!hu)
700 		return -EBADF;
701 
702 	switch (cmd) {
703 	case HCIUARTSETPROTO:
704 		if (!test_and_set_bit(HCI_UART_PROTO_SET, &hu->flags)) {
705 			err = hci_uart_set_proto(hu, arg);
706 			if (err) {
707 				clear_bit(HCI_UART_PROTO_SET, &hu->flags);
708 				return err;
709 			}
710 		} else
711 			return -EBUSY;
712 		break;
713 
714 	case HCIUARTGETPROTO:
715 		if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
716 			return hu->proto->id;
717 		return -EUNATCH;
718 
719 	case HCIUARTGETDEVICE:
720 		if (test_bit(HCI_UART_REGISTERED, &hu->flags))
721 			return hu->hdev->id;
722 		return -EUNATCH;
723 
724 	case HCIUARTSETFLAGS:
725 		if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
726 			return -EBUSY;
727 		err = hci_uart_set_flags(hu, arg);
728 		if (err)
729 			return err;
730 		break;
731 
732 	case HCIUARTGETFLAGS:
733 		return hu->hdev_flags;
734 
735 	default:
736 		err = n_tty_ioctl_helper(tty, file, cmd, arg);
737 		break;
738 	}
739 
740 	return err;
741 }
742 
743 /*
744  * We don't provide read/write/poll interface for user space.
745  */
746 static ssize_t hci_uart_tty_read(struct tty_struct *tty, struct file *file,
747 				 unsigned char __user *buf, size_t nr)
748 {
749 	return 0;
750 }
751 
752 static ssize_t hci_uart_tty_write(struct tty_struct *tty, struct file *file,
753 				  const unsigned char *data, size_t count)
754 {
755 	return 0;
756 }
757 
758 static unsigned int hci_uart_tty_poll(struct tty_struct *tty,
759 				      struct file *filp, poll_table *wait)
760 {
761 	return 0;
762 }
763 
764 static int __init hci_uart_init(void)
765 {
766 	static struct tty_ldisc_ops hci_uart_ldisc;
767 	int err;
768 
769 	BT_INFO("HCI UART driver ver %s", VERSION);
770 
771 	/* Register the tty discipline */
772 
773 	memset(&hci_uart_ldisc, 0, sizeof(hci_uart_ldisc));
774 	hci_uart_ldisc.magic		= TTY_LDISC_MAGIC;
775 	hci_uart_ldisc.name		= "n_hci";
776 	hci_uart_ldisc.open		= hci_uart_tty_open;
777 	hci_uart_ldisc.close		= hci_uart_tty_close;
778 	hci_uart_ldisc.read		= hci_uart_tty_read;
779 	hci_uart_ldisc.write		= hci_uart_tty_write;
780 	hci_uart_ldisc.ioctl		= hci_uart_tty_ioctl;
781 	hci_uart_ldisc.poll		= hci_uart_tty_poll;
782 	hci_uart_ldisc.receive_buf	= hci_uart_tty_receive;
783 	hci_uart_ldisc.write_wakeup	= hci_uart_tty_wakeup;
784 	hci_uart_ldisc.owner		= THIS_MODULE;
785 
786 	err = tty_register_ldisc(N_HCI, &hci_uart_ldisc);
787 	if (err) {
788 		BT_ERR("HCI line discipline registration failed. (%d)", err);
789 		return err;
790 	}
791 
792 #ifdef CONFIG_BT_HCIUART_H4
793 	h4_init();
794 #endif
795 #ifdef CONFIG_BT_HCIUART_BCSP
796 	bcsp_init();
797 #endif
798 #ifdef CONFIG_BT_HCIUART_LL
799 	ll_init();
800 #endif
801 #ifdef CONFIG_BT_HCIUART_ATH3K
802 	ath_init();
803 #endif
804 #ifdef CONFIG_BT_HCIUART_3WIRE
805 	h5_init();
806 #endif
807 #ifdef CONFIG_BT_HCIUART_INTEL
808 	intel_init();
809 #endif
810 #ifdef CONFIG_BT_HCIUART_BCM
811 	bcm_init();
812 #endif
813 #ifdef CONFIG_BT_HCIUART_QCA
814 	qca_init();
815 #endif
816 
817 	return 0;
818 }
819 
820 static void __exit hci_uart_exit(void)
821 {
822 	int err;
823 
824 #ifdef CONFIG_BT_HCIUART_H4
825 	h4_deinit();
826 #endif
827 #ifdef CONFIG_BT_HCIUART_BCSP
828 	bcsp_deinit();
829 #endif
830 #ifdef CONFIG_BT_HCIUART_LL
831 	ll_deinit();
832 #endif
833 #ifdef CONFIG_BT_HCIUART_ATH3K
834 	ath_deinit();
835 #endif
836 #ifdef CONFIG_BT_HCIUART_3WIRE
837 	h5_deinit();
838 #endif
839 #ifdef CONFIG_BT_HCIUART_INTEL
840 	intel_deinit();
841 #endif
842 #ifdef CONFIG_BT_HCIUART_BCM
843 	bcm_deinit();
844 #endif
845 #ifdef CONFIG_BT_HCIUART_QCA
846 	qca_deinit();
847 #endif
848 
849 	/* Release tty registration of line discipline */
850 	err = tty_unregister_ldisc(N_HCI);
851 	if (err)
852 		BT_ERR("Can't unregister HCI line discipline (%d)", err);
853 }
854 
855 module_init(hci_uart_init);
856 module_exit(hci_uart_exit);
857 
858 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
859 MODULE_DESCRIPTION("Bluetooth HCI UART driver ver " VERSION);
860 MODULE_VERSION(VERSION);
861 MODULE_LICENSE("GPL");
862 MODULE_ALIAS_LDISC(N_HCI);
863