xref: /openbmc/linux/drivers/bluetooth/hci_ldisc.c (revision bc5aa3a0)
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_READY, &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_READY, &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 	clear_bit(HCI_UART_PROTO_SET, &hu->flags);
504 
505 	kfree(hu);
506 }
507 
508 /* hci_uart_tty_wakeup()
509  *
510  *    Callback for transmit wakeup. Called when low level
511  *    device driver can accept more send data.
512  *
513  * Arguments:        tty    pointer to associated tty instance data
514  * Return Value:    None
515  */
516 static void hci_uart_tty_wakeup(struct tty_struct *tty)
517 {
518 	struct hci_uart *hu = tty->disc_data;
519 
520 	BT_DBG("");
521 
522 	if (!hu)
523 		return;
524 
525 	clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
526 
527 	if (tty != hu->tty)
528 		return;
529 
530 	if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
531 		hci_uart_tx_wakeup(hu);
532 }
533 
534 /* hci_uart_tty_receive()
535  *
536  *     Called by tty low level driver when receive data is
537  *     available.
538  *
539  * Arguments:  tty          pointer to tty isntance data
540  *             data         pointer to received data
541  *             flags        pointer to flags for data
542  *             count        count of received data in bytes
543  *
544  * Return Value:    None
545  */
546 static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data,
547 				 char *flags, int count)
548 {
549 	struct hci_uart *hu = tty->disc_data;
550 
551 	if (!hu || tty != hu->tty)
552 		return;
553 
554 	if (!test_bit(HCI_UART_PROTO_READY, &hu->flags))
555 		return;
556 
557 	/* It does not need a lock here as it is already protected by a mutex in
558 	 * tty caller
559 	 */
560 	hu->proto->recv(hu, data, count);
561 
562 	if (hu->hdev)
563 		hu->hdev->stat.byte_rx += count;
564 
565 	tty_unthrottle(tty);
566 }
567 
568 static int hci_uart_register_dev(struct hci_uart *hu)
569 {
570 	struct hci_dev *hdev;
571 
572 	BT_DBG("");
573 
574 	/* Initialize and register HCI device */
575 	hdev = hci_alloc_dev();
576 	if (!hdev) {
577 		BT_ERR("Can't allocate HCI device");
578 		return -ENOMEM;
579 	}
580 
581 	hu->hdev = hdev;
582 
583 	hdev->bus = HCI_UART;
584 	hci_set_drvdata(hdev, hu);
585 
586 	/* Only when vendor specific setup callback is provided, consider
587 	 * the manufacturer information valid. This avoids filling in the
588 	 * value for Ericsson when nothing is specified.
589 	 */
590 	if (hu->proto->setup)
591 		hdev->manufacturer = hu->proto->manufacturer;
592 
593 	hdev->open  = hci_uart_open;
594 	hdev->close = hci_uart_close;
595 	hdev->flush = hci_uart_flush;
596 	hdev->send  = hci_uart_send_frame;
597 	hdev->setup = hci_uart_setup;
598 	SET_HCIDEV_DEV(hdev, hu->tty->dev);
599 
600 	if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags))
601 		set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
602 
603 	if (test_bit(HCI_UART_EXT_CONFIG, &hu->hdev_flags))
604 		set_bit(HCI_QUIRK_EXTERNAL_CONFIG, &hdev->quirks);
605 
606 	if (!test_bit(HCI_UART_RESET_ON_INIT, &hu->hdev_flags))
607 		set_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks);
608 
609 	if (test_bit(HCI_UART_CREATE_AMP, &hu->hdev_flags))
610 		hdev->dev_type = HCI_AMP;
611 	else
612 		hdev->dev_type = HCI_PRIMARY;
613 
614 	if (test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
615 		return 0;
616 
617 	if (hci_register_dev(hdev) < 0) {
618 		BT_ERR("Can't register HCI device");
619 		hci_free_dev(hdev);
620 		return -ENODEV;
621 	}
622 
623 	set_bit(HCI_UART_REGISTERED, &hu->flags);
624 
625 	return 0;
626 }
627 
628 static int hci_uart_set_proto(struct hci_uart *hu, int id)
629 {
630 	const struct hci_uart_proto *p;
631 	int err;
632 
633 	p = hci_uart_get_proto(id);
634 	if (!p)
635 		return -EPROTONOSUPPORT;
636 
637 	err = p->open(hu);
638 	if (err)
639 		return err;
640 
641 	hu->proto = p;
642 	set_bit(HCI_UART_PROTO_READY, &hu->flags);
643 
644 	err = hci_uart_register_dev(hu);
645 	if (err) {
646 		clear_bit(HCI_UART_PROTO_READY, &hu->flags);
647 		p->close(hu);
648 		return err;
649 	}
650 
651 	return 0;
652 }
653 
654 static int hci_uart_set_flags(struct hci_uart *hu, unsigned long flags)
655 {
656 	unsigned long valid_flags = BIT(HCI_UART_RAW_DEVICE) |
657 				    BIT(HCI_UART_RESET_ON_INIT) |
658 				    BIT(HCI_UART_CREATE_AMP) |
659 				    BIT(HCI_UART_INIT_PENDING) |
660 				    BIT(HCI_UART_EXT_CONFIG) |
661 				    BIT(HCI_UART_VND_DETECT);
662 
663 	if (flags & ~valid_flags)
664 		return -EINVAL;
665 
666 	hu->hdev_flags = flags;
667 
668 	return 0;
669 }
670 
671 /* hci_uart_tty_ioctl()
672  *
673  *    Process IOCTL system call for the tty device.
674  *
675  * Arguments:
676  *
677  *    tty        pointer to tty instance data
678  *    file       pointer to open file object for device
679  *    cmd        IOCTL command code
680  *    arg        argument for IOCTL call (cmd dependent)
681  *
682  * Return Value:    Command dependent
683  */
684 static int hci_uart_tty_ioctl(struct tty_struct *tty, struct file *file,
685 			      unsigned int cmd, unsigned long arg)
686 {
687 	struct hci_uart *hu = tty->disc_data;
688 	int err = 0;
689 
690 	BT_DBG("");
691 
692 	/* Verify the status of the device */
693 	if (!hu)
694 		return -EBADF;
695 
696 	switch (cmd) {
697 	case HCIUARTSETPROTO:
698 		if (!test_and_set_bit(HCI_UART_PROTO_SET, &hu->flags)) {
699 			err = hci_uart_set_proto(hu, arg);
700 			if (err) {
701 				clear_bit(HCI_UART_PROTO_SET, &hu->flags);
702 				return err;
703 			}
704 		} else
705 			return -EBUSY;
706 		break;
707 
708 	case HCIUARTGETPROTO:
709 		if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
710 			return hu->proto->id;
711 		return -EUNATCH;
712 
713 	case HCIUARTGETDEVICE:
714 		if (test_bit(HCI_UART_REGISTERED, &hu->flags))
715 			return hu->hdev->id;
716 		return -EUNATCH;
717 
718 	case HCIUARTSETFLAGS:
719 		if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
720 			return -EBUSY;
721 		err = hci_uart_set_flags(hu, arg);
722 		if (err)
723 			return err;
724 		break;
725 
726 	case HCIUARTGETFLAGS:
727 		return hu->hdev_flags;
728 
729 	default:
730 		err = n_tty_ioctl_helper(tty, file, cmd, arg);
731 		break;
732 	}
733 
734 	return err;
735 }
736 
737 /*
738  * We don't provide read/write/poll interface for user space.
739  */
740 static ssize_t hci_uart_tty_read(struct tty_struct *tty, struct file *file,
741 				 unsigned char __user *buf, size_t nr)
742 {
743 	return 0;
744 }
745 
746 static ssize_t hci_uart_tty_write(struct tty_struct *tty, struct file *file,
747 				  const unsigned char *data, size_t count)
748 {
749 	return 0;
750 }
751 
752 static unsigned int hci_uart_tty_poll(struct tty_struct *tty,
753 				      struct file *filp, poll_table *wait)
754 {
755 	return 0;
756 }
757 
758 static int __init hci_uart_init(void)
759 {
760 	static struct tty_ldisc_ops hci_uart_ldisc;
761 	int err;
762 
763 	BT_INFO("HCI UART driver ver %s", VERSION);
764 
765 	/* Register the tty discipline */
766 
767 	memset(&hci_uart_ldisc, 0, sizeof(hci_uart_ldisc));
768 	hci_uart_ldisc.magic		= TTY_LDISC_MAGIC;
769 	hci_uart_ldisc.name		= "n_hci";
770 	hci_uart_ldisc.open		= hci_uart_tty_open;
771 	hci_uart_ldisc.close		= hci_uart_tty_close;
772 	hci_uart_ldisc.read		= hci_uart_tty_read;
773 	hci_uart_ldisc.write		= hci_uart_tty_write;
774 	hci_uart_ldisc.ioctl		= hci_uart_tty_ioctl;
775 	hci_uart_ldisc.poll		= hci_uart_tty_poll;
776 	hci_uart_ldisc.receive_buf	= hci_uart_tty_receive;
777 	hci_uart_ldisc.write_wakeup	= hci_uart_tty_wakeup;
778 	hci_uart_ldisc.owner		= THIS_MODULE;
779 
780 	err = tty_register_ldisc(N_HCI, &hci_uart_ldisc);
781 	if (err) {
782 		BT_ERR("HCI line discipline registration failed. (%d)", err);
783 		return err;
784 	}
785 
786 #ifdef CONFIG_BT_HCIUART_H4
787 	h4_init();
788 #endif
789 #ifdef CONFIG_BT_HCIUART_BCSP
790 	bcsp_init();
791 #endif
792 #ifdef CONFIG_BT_HCIUART_LL
793 	ll_init();
794 #endif
795 #ifdef CONFIG_BT_HCIUART_ATH3K
796 	ath_init();
797 #endif
798 #ifdef CONFIG_BT_HCIUART_3WIRE
799 	h5_init();
800 #endif
801 #ifdef CONFIG_BT_HCIUART_INTEL
802 	intel_init();
803 #endif
804 #ifdef CONFIG_BT_HCIUART_BCM
805 	bcm_init();
806 #endif
807 #ifdef CONFIG_BT_HCIUART_QCA
808 	qca_init();
809 #endif
810 #ifdef CONFIG_BT_HCIUART_AG6XX
811 	ag6xx_init();
812 #endif
813 
814 	return 0;
815 }
816 
817 static void __exit hci_uart_exit(void)
818 {
819 	int err;
820 
821 #ifdef CONFIG_BT_HCIUART_H4
822 	h4_deinit();
823 #endif
824 #ifdef CONFIG_BT_HCIUART_BCSP
825 	bcsp_deinit();
826 #endif
827 #ifdef CONFIG_BT_HCIUART_LL
828 	ll_deinit();
829 #endif
830 #ifdef CONFIG_BT_HCIUART_ATH3K
831 	ath_deinit();
832 #endif
833 #ifdef CONFIG_BT_HCIUART_3WIRE
834 	h5_deinit();
835 #endif
836 #ifdef CONFIG_BT_HCIUART_INTEL
837 	intel_deinit();
838 #endif
839 #ifdef CONFIG_BT_HCIUART_BCM
840 	bcm_deinit();
841 #endif
842 #ifdef CONFIG_BT_HCIUART_QCA
843 	qca_deinit();
844 #endif
845 #ifdef CONFIG_BT_HCIUART_AG6XX
846 	ag6xx_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