xref: /openbmc/linux/drivers/bluetooth/hci_ldisc.c (revision a06c488d)
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, hci_skb_pkt_type(skb));
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 	return 0;
212 }
213 
214 /* Reset device */
215 static int hci_uart_flush(struct hci_dev *hdev)
216 {
217 	struct hci_uart *hu  = hci_get_drvdata(hdev);
218 	struct tty_struct *tty = hu->tty;
219 
220 	BT_DBG("hdev %p tty %p", hdev, tty);
221 
222 	if (hu->tx_skb) {
223 		kfree_skb(hu->tx_skb); hu->tx_skb = NULL;
224 	}
225 
226 	/* Flush any pending characters in the driver and discipline. */
227 	tty_ldisc_flush(tty);
228 	tty_driver_flush_buffer(tty);
229 
230 	if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
231 		hu->proto->flush(hu);
232 
233 	return 0;
234 }
235 
236 /* Close device */
237 static int hci_uart_close(struct hci_dev *hdev)
238 {
239 	BT_DBG("hdev %p", hdev);
240 
241 	hci_uart_flush(hdev);
242 	hdev->flush = NULL;
243 	return 0;
244 }
245 
246 /* Send frames from HCI layer */
247 static int hci_uart_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
248 {
249 	struct hci_uart *hu = hci_get_drvdata(hdev);
250 
251 	BT_DBG("%s: type %d len %d", hdev->name, hci_skb_pkt_type(skb),
252 	       skb->len);
253 
254 	hu->proto->enqueue(hu, skb);
255 
256 	hci_uart_tx_wakeup(hu);
257 
258 	return 0;
259 }
260 
261 /* Flow control or un-flow control the device */
262 void hci_uart_set_flow_control(struct hci_uart *hu, bool enable)
263 {
264 	struct tty_struct *tty = hu->tty;
265 	struct ktermios ktermios;
266 	int status;
267 	unsigned int set = 0;
268 	unsigned int clear = 0;
269 
270 	if (enable) {
271 		/* Disable hardware flow control */
272 		ktermios = tty->termios;
273 		ktermios.c_cflag &= ~CRTSCTS;
274 		status = tty_set_termios(tty, &ktermios);
275 		BT_DBG("Disabling hardware flow control: %s",
276 		       status ? "failed" : "success");
277 
278 		/* Clear RTS to prevent the device from sending */
279 		/* Most UARTs need OUT2 to enable interrupts */
280 		status = tty->driver->ops->tiocmget(tty);
281 		BT_DBG("Current tiocm 0x%x", status);
282 
283 		set &= ~(TIOCM_OUT2 | TIOCM_RTS);
284 		clear = ~set;
285 		set &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
286 		       TIOCM_OUT2 | TIOCM_LOOP;
287 		clear &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
288 			 TIOCM_OUT2 | TIOCM_LOOP;
289 		status = tty->driver->ops->tiocmset(tty, set, clear);
290 		BT_DBG("Clearing RTS: %s", status ? "failed" : "success");
291 	} else {
292 		/* Set RTS to allow the device to send again */
293 		status = tty->driver->ops->tiocmget(tty);
294 		BT_DBG("Current tiocm 0x%x", status);
295 
296 		set |= (TIOCM_OUT2 | TIOCM_RTS);
297 		clear = ~set;
298 		set &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
299 		       TIOCM_OUT2 | TIOCM_LOOP;
300 		clear &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
301 			 TIOCM_OUT2 | TIOCM_LOOP;
302 		status = tty->driver->ops->tiocmset(tty, set, clear);
303 		BT_DBG("Setting RTS: %s", status ? "failed" : "success");
304 
305 		/* Re-enable hardware flow control */
306 		ktermios = tty->termios;
307 		ktermios.c_cflag |= CRTSCTS;
308 		status = tty_set_termios(tty, &ktermios);
309 		BT_DBG("Enabling hardware flow control: %s",
310 		       status ? "failed" : "success");
311 	}
312 }
313 
314 void hci_uart_set_speeds(struct hci_uart *hu, unsigned int init_speed,
315 			 unsigned int oper_speed)
316 {
317 	hu->init_speed = init_speed;
318 	hu->oper_speed = oper_speed;
319 }
320 
321 void hci_uart_init_tty(struct hci_uart *hu)
322 {
323 	struct tty_struct *tty = hu->tty;
324 	struct ktermios ktermios;
325 
326 	/* Bring the UART into a known 8 bits no parity hw fc state */
327 	ktermios = tty->termios;
328 	ktermios.c_iflag &= ~(IGNBRK | BRKINT | PARMRK | ISTRIP |
329 			      INLCR | IGNCR | ICRNL | IXON);
330 	ktermios.c_oflag &= ~OPOST;
331 	ktermios.c_lflag &= ~(ECHO | ECHONL | ICANON | ISIG | IEXTEN);
332 	ktermios.c_cflag &= ~(CSIZE | PARENB);
333 	ktermios.c_cflag |= CS8;
334 	ktermios.c_cflag |= CRTSCTS;
335 
336 	/* tty_set_termios() return not checked as it is always 0 */
337 	tty_set_termios(tty, &ktermios);
338 }
339 
340 void hci_uart_set_baudrate(struct hci_uart *hu, unsigned int speed)
341 {
342 	struct tty_struct *tty = hu->tty;
343 	struct ktermios ktermios;
344 
345 	ktermios = tty->termios;
346 	ktermios.c_cflag &= ~CBAUD;
347 	tty_termios_encode_baud_rate(&ktermios, speed, speed);
348 
349 	/* tty_set_termios() return not checked as it is always 0 */
350 	tty_set_termios(tty, &ktermios);
351 
352 	BT_DBG("%s: New tty speeds: %d/%d", hu->hdev->name,
353 	       tty->termios.c_ispeed, tty->termios.c_ospeed);
354 }
355 
356 static int hci_uart_setup(struct hci_dev *hdev)
357 {
358 	struct hci_uart *hu = hci_get_drvdata(hdev);
359 	struct hci_rp_read_local_version *ver;
360 	struct sk_buff *skb;
361 	unsigned int speed;
362 	int err;
363 
364 	/* Init speed if any */
365 	if (hu->init_speed)
366 		speed = hu->init_speed;
367 	else if (hu->proto->init_speed)
368 		speed = hu->proto->init_speed;
369 	else
370 		speed = 0;
371 
372 	if (speed)
373 		hci_uart_set_baudrate(hu, speed);
374 
375 	/* Operational speed if any */
376 	if (hu->oper_speed)
377 		speed = hu->oper_speed;
378 	else if (hu->proto->oper_speed)
379 		speed = hu->proto->oper_speed;
380 	else
381 		speed = 0;
382 
383 	if (hu->proto->set_baudrate && speed) {
384 		err = hu->proto->set_baudrate(hu, speed);
385 		if (!err)
386 			hci_uart_set_baudrate(hu, speed);
387 	}
388 
389 	if (hu->proto->setup)
390 		return hu->proto->setup(hu);
391 
392 	if (!test_bit(HCI_UART_VND_DETECT, &hu->hdev_flags))
393 		return 0;
394 
395 	skb = __hci_cmd_sync(hdev, HCI_OP_READ_LOCAL_VERSION, 0, NULL,
396 			     HCI_INIT_TIMEOUT);
397 	if (IS_ERR(skb)) {
398 		BT_ERR("%s: Reading local version information failed (%ld)",
399 		       hdev->name, PTR_ERR(skb));
400 		return 0;
401 	}
402 
403 	if (skb->len != sizeof(*ver)) {
404 		BT_ERR("%s: Event length mismatch for version information",
405 		       hdev->name);
406 		goto done;
407 	}
408 
409 	ver = (struct hci_rp_read_local_version *)skb->data;
410 
411 	switch (le16_to_cpu(ver->manufacturer)) {
412 #ifdef CONFIG_BT_HCIUART_INTEL
413 	case 2:
414 		hdev->set_bdaddr = btintel_set_bdaddr;
415 		btintel_check_bdaddr(hdev);
416 		break;
417 #endif
418 #ifdef CONFIG_BT_HCIUART_BCM
419 	case 15:
420 		hdev->set_bdaddr = btbcm_set_bdaddr;
421 		btbcm_check_bdaddr(hdev);
422 		break;
423 #endif
424 	}
425 
426 done:
427 	kfree_skb(skb);
428 	return 0;
429 }
430 
431 /* ------ LDISC part ------ */
432 /* hci_uart_tty_open
433  *
434  *     Called when line discipline changed to HCI_UART.
435  *
436  * Arguments:
437  *     tty    pointer to tty info structure
438  * Return Value:
439  *     0 if success, otherwise error code
440  */
441 static int hci_uart_tty_open(struct tty_struct *tty)
442 {
443 	struct hci_uart *hu;
444 
445 	BT_DBG("tty %p", tty);
446 
447 	/* Error if the tty has no write op instead of leaving an exploitable
448 	   hole */
449 	if (tty->ops->write == NULL)
450 		return -EOPNOTSUPP;
451 
452 	hu = kzalloc(sizeof(struct hci_uart), GFP_KERNEL);
453 	if (!hu) {
454 		BT_ERR("Can't allocate control structure");
455 		return -ENFILE;
456 	}
457 
458 	tty->disc_data = hu;
459 	hu->tty = tty;
460 	tty->receive_room = 65536;
461 
462 	INIT_WORK(&hu->init_ready, hci_uart_init_work);
463 	INIT_WORK(&hu->write_work, hci_uart_write_work);
464 
465 	/* Flush any pending characters in the driver */
466 	tty_driver_flush_buffer(tty);
467 
468 	return 0;
469 }
470 
471 /* hci_uart_tty_close()
472  *
473  *    Called when the line discipline is changed to something
474  *    else, the tty is closed, or the tty detects a hangup.
475  */
476 static void hci_uart_tty_close(struct tty_struct *tty)
477 {
478 	struct hci_uart *hu = tty->disc_data;
479 	struct hci_dev *hdev;
480 
481 	BT_DBG("tty %p", tty);
482 
483 	/* Detach from the tty */
484 	tty->disc_data = NULL;
485 
486 	if (!hu)
487 		return;
488 
489 	hdev = hu->hdev;
490 	if (hdev)
491 		hci_uart_close(hdev);
492 
493 	cancel_work_sync(&hu->write_work);
494 
495 	if (test_and_clear_bit(HCI_UART_PROTO_SET, &hu->flags)) {
496 		if (hdev) {
497 			if (test_bit(HCI_UART_REGISTERED, &hu->flags))
498 				hci_unregister_dev(hdev);
499 			hci_free_dev(hdev);
500 		}
501 		hu->proto->close(hu);
502 	}
503 
504 	kfree(hu);
505 }
506 
507 /* hci_uart_tty_wakeup()
508  *
509  *    Callback for transmit wakeup. Called when low level
510  *    device driver can accept more send data.
511  *
512  * Arguments:        tty    pointer to associated tty instance data
513  * Return Value:    None
514  */
515 static void hci_uart_tty_wakeup(struct tty_struct *tty)
516 {
517 	struct hci_uart *hu = tty->disc_data;
518 
519 	BT_DBG("");
520 
521 	if (!hu)
522 		return;
523 
524 	clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
525 
526 	if (tty != hu->tty)
527 		return;
528 
529 	if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
530 		hci_uart_tx_wakeup(hu);
531 }
532 
533 /* hci_uart_tty_receive()
534  *
535  *     Called by tty low level driver when receive data is
536  *     available.
537  *
538  * Arguments:  tty          pointer to tty isntance data
539  *             data         pointer to received data
540  *             flags        pointer to flags for data
541  *             count        count of received data in bytes
542  *
543  * Return Value:    None
544  */
545 static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data,
546 				 char *flags, int count)
547 {
548 	struct hci_uart *hu = tty->disc_data;
549 
550 	if (!hu || tty != hu->tty)
551 		return;
552 
553 	if (!test_bit(HCI_UART_PROTO_SET, &hu->flags))
554 		return;
555 
556 	/* It does not need a lock here as it is already protected by a mutex in
557 	 * tty caller
558 	 */
559 	hu->proto->recv(hu, data, count);
560 
561 	if (hu->hdev)
562 		hu->hdev->stat.byte_rx += count;
563 
564 	tty_unthrottle(tty);
565 }
566 
567 static int hci_uart_register_dev(struct hci_uart *hu)
568 {
569 	struct hci_dev *hdev;
570 
571 	BT_DBG("");
572 
573 	/* Initialize and register HCI device */
574 	hdev = hci_alloc_dev();
575 	if (!hdev) {
576 		BT_ERR("Can't allocate HCI device");
577 		return -ENOMEM;
578 	}
579 
580 	hu->hdev = hdev;
581 
582 	hdev->bus = HCI_UART;
583 	hci_set_drvdata(hdev, hu);
584 
585 	/* Only when vendor specific setup callback is provided, consider
586 	 * the manufacturer information valid. This avoids filling in the
587 	 * value for Ericsson when nothing is specified.
588 	 */
589 	if (hu->proto->setup)
590 		hdev->manufacturer = hu->proto->manufacturer;
591 
592 	hdev->open  = hci_uart_open;
593 	hdev->close = hci_uart_close;
594 	hdev->flush = hci_uart_flush;
595 	hdev->send  = hci_uart_send_frame;
596 	hdev->setup = hci_uart_setup;
597 	SET_HCIDEV_DEV(hdev, hu->tty->dev);
598 
599 	if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags))
600 		set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
601 
602 	if (test_bit(HCI_UART_EXT_CONFIG, &hu->hdev_flags))
603 		set_bit(HCI_QUIRK_EXTERNAL_CONFIG, &hdev->quirks);
604 
605 	if (!test_bit(HCI_UART_RESET_ON_INIT, &hu->hdev_flags))
606 		set_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks);
607 
608 	if (test_bit(HCI_UART_CREATE_AMP, &hu->hdev_flags))
609 		hdev->dev_type = HCI_AMP;
610 	else
611 		hdev->dev_type = HCI_BREDR;
612 
613 	if (test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
614 		return 0;
615 
616 	if (hci_register_dev(hdev) < 0) {
617 		BT_ERR("Can't register HCI device");
618 		hci_free_dev(hdev);
619 		return -ENODEV;
620 	}
621 
622 	set_bit(HCI_UART_REGISTERED, &hu->flags);
623 
624 	return 0;
625 }
626 
627 static int hci_uart_set_proto(struct hci_uart *hu, int id)
628 {
629 	const struct hci_uart_proto *p;
630 	int err;
631 
632 	p = hci_uart_get_proto(id);
633 	if (!p)
634 		return -EPROTONOSUPPORT;
635 
636 	err = p->open(hu);
637 	if (err)
638 		return err;
639 
640 	hu->proto = p;
641 
642 	err = hci_uart_register_dev(hu);
643 	if (err) {
644 		p->close(hu);
645 		return err;
646 	}
647 
648 	return 0;
649 }
650 
651 static int hci_uart_set_flags(struct hci_uart *hu, unsigned long flags)
652 {
653 	unsigned long valid_flags = BIT(HCI_UART_RAW_DEVICE) |
654 				    BIT(HCI_UART_RESET_ON_INIT) |
655 				    BIT(HCI_UART_CREATE_AMP) |
656 				    BIT(HCI_UART_INIT_PENDING) |
657 				    BIT(HCI_UART_EXT_CONFIG) |
658 				    BIT(HCI_UART_VND_DETECT);
659 
660 	if (flags & ~valid_flags)
661 		return -EINVAL;
662 
663 	hu->hdev_flags = flags;
664 
665 	return 0;
666 }
667 
668 /* hci_uart_tty_ioctl()
669  *
670  *    Process IOCTL system call for the tty device.
671  *
672  * Arguments:
673  *
674  *    tty        pointer to tty instance data
675  *    file       pointer to open file object for device
676  *    cmd        IOCTL command code
677  *    arg        argument for IOCTL call (cmd dependent)
678  *
679  * Return Value:    Command dependent
680  */
681 static int hci_uart_tty_ioctl(struct tty_struct *tty, struct file *file,
682 			      unsigned int cmd, unsigned long arg)
683 {
684 	struct hci_uart *hu = tty->disc_data;
685 	int err = 0;
686 
687 	BT_DBG("");
688 
689 	/* Verify the status of the device */
690 	if (!hu)
691 		return -EBADF;
692 
693 	switch (cmd) {
694 	case HCIUARTSETPROTO:
695 		if (!test_and_set_bit(HCI_UART_PROTO_SET, &hu->flags)) {
696 			err = hci_uart_set_proto(hu, arg);
697 			if (err) {
698 				clear_bit(HCI_UART_PROTO_SET, &hu->flags);
699 				return err;
700 			}
701 		} else
702 			return -EBUSY;
703 		break;
704 
705 	case HCIUARTGETPROTO:
706 		if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
707 			return hu->proto->id;
708 		return -EUNATCH;
709 
710 	case HCIUARTGETDEVICE:
711 		if (test_bit(HCI_UART_REGISTERED, &hu->flags))
712 			return hu->hdev->id;
713 		return -EUNATCH;
714 
715 	case HCIUARTSETFLAGS:
716 		if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
717 			return -EBUSY;
718 		err = hci_uart_set_flags(hu, arg);
719 		if (err)
720 			return err;
721 		break;
722 
723 	case HCIUARTGETFLAGS:
724 		return hu->hdev_flags;
725 
726 	default:
727 		err = n_tty_ioctl_helper(tty, file, cmd, arg);
728 		break;
729 	}
730 
731 	return err;
732 }
733 
734 /*
735  * We don't provide read/write/poll interface for user space.
736  */
737 static ssize_t hci_uart_tty_read(struct tty_struct *tty, struct file *file,
738 				 unsigned char __user *buf, size_t nr)
739 {
740 	return 0;
741 }
742 
743 static ssize_t hci_uart_tty_write(struct tty_struct *tty, struct file *file,
744 				  const unsigned char *data, size_t count)
745 {
746 	return 0;
747 }
748 
749 static unsigned int hci_uart_tty_poll(struct tty_struct *tty,
750 				      struct file *filp, poll_table *wait)
751 {
752 	return 0;
753 }
754 
755 static int __init hci_uart_init(void)
756 {
757 	static struct tty_ldisc_ops hci_uart_ldisc;
758 	int err;
759 
760 	BT_INFO("HCI UART driver ver %s", VERSION);
761 
762 	/* Register the tty discipline */
763 
764 	memset(&hci_uart_ldisc, 0, sizeof(hci_uart_ldisc));
765 	hci_uart_ldisc.magic		= TTY_LDISC_MAGIC;
766 	hci_uart_ldisc.name		= "n_hci";
767 	hci_uart_ldisc.open		= hci_uart_tty_open;
768 	hci_uart_ldisc.close		= hci_uart_tty_close;
769 	hci_uart_ldisc.read		= hci_uart_tty_read;
770 	hci_uart_ldisc.write		= hci_uart_tty_write;
771 	hci_uart_ldisc.ioctl		= hci_uart_tty_ioctl;
772 	hci_uart_ldisc.poll		= hci_uart_tty_poll;
773 	hci_uart_ldisc.receive_buf	= hci_uart_tty_receive;
774 	hci_uart_ldisc.write_wakeup	= hci_uart_tty_wakeup;
775 	hci_uart_ldisc.owner		= THIS_MODULE;
776 
777 	err = tty_register_ldisc(N_HCI, &hci_uart_ldisc);
778 	if (err) {
779 		BT_ERR("HCI line discipline registration failed. (%d)", err);
780 		return err;
781 	}
782 
783 #ifdef CONFIG_BT_HCIUART_H4
784 	h4_init();
785 #endif
786 #ifdef CONFIG_BT_HCIUART_BCSP
787 	bcsp_init();
788 #endif
789 #ifdef CONFIG_BT_HCIUART_LL
790 	ll_init();
791 #endif
792 #ifdef CONFIG_BT_HCIUART_ATH3K
793 	ath_init();
794 #endif
795 #ifdef CONFIG_BT_HCIUART_3WIRE
796 	h5_init();
797 #endif
798 #ifdef CONFIG_BT_HCIUART_INTEL
799 	intel_init();
800 #endif
801 #ifdef CONFIG_BT_HCIUART_BCM
802 	bcm_init();
803 #endif
804 #ifdef CONFIG_BT_HCIUART_QCA
805 	qca_init();
806 #endif
807 
808 	return 0;
809 }
810 
811 static void __exit hci_uart_exit(void)
812 {
813 	int err;
814 
815 #ifdef CONFIG_BT_HCIUART_H4
816 	h4_deinit();
817 #endif
818 #ifdef CONFIG_BT_HCIUART_BCSP
819 	bcsp_deinit();
820 #endif
821 #ifdef CONFIG_BT_HCIUART_LL
822 	ll_deinit();
823 #endif
824 #ifdef CONFIG_BT_HCIUART_ATH3K
825 	ath_deinit();
826 #endif
827 #ifdef CONFIG_BT_HCIUART_3WIRE
828 	h5_deinit();
829 #endif
830 #ifdef CONFIG_BT_HCIUART_INTEL
831 	intel_deinit();
832 #endif
833 #ifdef CONFIG_BT_HCIUART_BCM
834 	bcm_deinit();
835 #endif
836 #ifdef CONFIG_BT_HCIUART_QCA
837 	qca_deinit();
838 #endif
839 
840 	/* Release tty registration of line discipline */
841 	err = tty_unregister_ldisc(N_HCI);
842 	if (err)
843 		BT_ERR("Can't unregister HCI line discipline (%d)", err);
844 }
845 
846 module_init(hci_uart_init);
847 module_exit(hci_uart_exit);
848 
849 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
850 MODULE_DESCRIPTION("Bluetooth HCI UART driver ver " VERSION);
851 MODULE_VERSION(VERSION);
852 MODULE_LICENSE("GPL");
853 MODULE_ALIAS_LDISC(N_HCI);
854