xref: /openbmc/linux/drivers/bluetooth/hci_ldisc.c (revision 5b4cb650)
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 #include <linux/serdev.h>
45 
46 #include <net/bluetooth/bluetooth.h>
47 #include <net/bluetooth/hci_core.h>
48 
49 #include "btintel.h"
50 #include "btbcm.h"
51 #include "hci_uart.h"
52 
53 #define VERSION "2.3"
54 
55 static const struct hci_uart_proto *hup[HCI_UART_MAX_PROTO];
56 
57 int hci_uart_register_proto(const struct hci_uart_proto *p)
58 {
59 	if (p->id >= HCI_UART_MAX_PROTO)
60 		return -EINVAL;
61 
62 	if (hup[p->id])
63 		return -EEXIST;
64 
65 	hup[p->id] = p;
66 
67 	BT_INFO("HCI UART protocol %s registered", p->name);
68 
69 	return 0;
70 }
71 
72 int hci_uart_unregister_proto(const struct hci_uart_proto *p)
73 {
74 	if (p->id >= HCI_UART_MAX_PROTO)
75 		return -EINVAL;
76 
77 	if (!hup[p->id])
78 		return -EINVAL;
79 
80 	hup[p->id] = NULL;
81 
82 	return 0;
83 }
84 
85 static const struct hci_uart_proto *hci_uart_get_proto(unsigned int id)
86 {
87 	if (id >= HCI_UART_MAX_PROTO)
88 		return NULL;
89 
90 	return hup[id];
91 }
92 
93 static inline void hci_uart_tx_complete(struct hci_uart *hu, int pkt_type)
94 {
95 	struct hci_dev *hdev = hu->hdev;
96 
97 	/* Update HCI stat counters */
98 	switch (pkt_type) {
99 	case HCI_COMMAND_PKT:
100 		hdev->stat.cmd_tx++;
101 		break;
102 
103 	case HCI_ACLDATA_PKT:
104 		hdev->stat.acl_tx++;
105 		break;
106 
107 	case HCI_SCODATA_PKT:
108 		hdev->stat.sco_tx++;
109 		break;
110 	}
111 }
112 
113 static inline struct sk_buff *hci_uart_dequeue(struct hci_uart *hu)
114 {
115 	struct sk_buff *skb = hu->tx_skb;
116 
117 	if (!skb) {
118 		percpu_down_read(&hu->proto_lock);
119 
120 		if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
121 			skb = hu->proto->dequeue(hu);
122 
123 		percpu_up_read(&hu->proto_lock);
124 	} else {
125 		hu->tx_skb = NULL;
126 	}
127 
128 	return skb;
129 }
130 
131 int hci_uart_tx_wakeup(struct hci_uart *hu)
132 {
133 	/* This may be called in an IRQ context, so we can't sleep. Therefore
134 	 * we try to acquire the lock only, and if that fails we assume the
135 	 * tty is being closed because that is the only time the write lock is
136 	 * acquired. If, however, at some point in the future the write lock
137 	 * is also acquired in other situations, then this must be revisited.
138 	 */
139 	if (!percpu_down_read_trylock(&hu->proto_lock))
140 		return 0;
141 
142 	if (!test_bit(HCI_UART_PROTO_READY, &hu->flags))
143 		goto no_schedule;
144 
145 	if (test_and_set_bit(HCI_UART_SENDING, &hu->tx_state)) {
146 		set_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
147 		goto no_schedule;
148 	}
149 
150 	BT_DBG("");
151 
152 	schedule_work(&hu->write_work);
153 
154 no_schedule:
155 	percpu_up_read(&hu->proto_lock);
156 
157 	return 0;
158 }
159 EXPORT_SYMBOL_GPL(hci_uart_tx_wakeup);
160 
161 static void hci_uart_write_work(struct work_struct *work)
162 {
163 	struct hci_uart *hu = container_of(work, struct hci_uart, write_work);
164 	struct tty_struct *tty = hu->tty;
165 	struct hci_dev *hdev = hu->hdev;
166 	struct sk_buff *skb;
167 
168 	/* REVISIT: should we cope with bad skbs or ->write() returning
169 	 * and error value ?
170 	 */
171 
172 restart:
173 	clear_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
174 
175 	while ((skb = hci_uart_dequeue(hu))) {
176 		int len;
177 
178 		set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
179 		len = tty->ops->write(tty, skb->data, skb->len);
180 		hdev->stat.byte_tx += len;
181 
182 		skb_pull(skb, len);
183 		if (skb->len) {
184 			hu->tx_skb = skb;
185 			break;
186 		}
187 
188 		hci_uart_tx_complete(hu, hci_skb_pkt_type(skb));
189 		kfree_skb(skb);
190 	}
191 
192 	if (test_bit(HCI_UART_TX_WAKEUP, &hu->tx_state))
193 		goto restart;
194 
195 	clear_bit(HCI_UART_SENDING, &hu->tx_state);
196 }
197 
198 void hci_uart_init_work(struct work_struct *work)
199 {
200 	struct hci_uart *hu = container_of(work, struct hci_uart, init_ready);
201 	int err;
202 	struct hci_dev *hdev;
203 
204 	if (!test_and_clear_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
205 		return;
206 
207 	err = hci_register_dev(hu->hdev);
208 	if (err < 0) {
209 		BT_ERR("Can't register HCI device");
210 		hdev = hu->hdev;
211 		hu->hdev = NULL;
212 		hci_free_dev(hdev);
213 		clear_bit(HCI_UART_PROTO_READY, &hu->flags);
214 		hu->proto->close(hu);
215 		return;
216 	}
217 
218 	set_bit(HCI_UART_REGISTERED, &hu->flags);
219 }
220 
221 int hci_uart_init_ready(struct hci_uart *hu)
222 {
223 	if (!test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
224 		return -EALREADY;
225 
226 	schedule_work(&hu->init_ready);
227 
228 	return 0;
229 }
230 
231 /* ------- Interface to HCI layer ------ */
232 /* Reset device */
233 static int hci_uart_flush(struct hci_dev *hdev)
234 {
235 	struct hci_uart *hu  = hci_get_drvdata(hdev);
236 	struct tty_struct *tty = hu->tty;
237 
238 	BT_DBG("hdev %p tty %p", hdev, tty);
239 
240 	if (hu->tx_skb) {
241 		kfree_skb(hu->tx_skb); hu->tx_skb = NULL;
242 	}
243 
244 	/* Flush any pending characters in the driver and discipline. */
245 	tty_ldisc_flush(tty);
246 	tty_driver_flush_buffer(tty);
247 
248 	percpu_down_read(&hu->proto_lock);
249 
250 	if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
251 		hu->proto->flush(hu);
252 
253 	percpu_up_read(&hu->proto_lock);
254 
255 	return 0;
256 }
257 
258 /* Initialize device */
259 static int hci_uart_open(struct hci_dev *hdev)
260 {
261 	BT_DBG("%s %p", hdev->name, hdev);
262 
263 	/* Undo clearing this from hci_uart_close() */
264 	hdev->flush = hci_uart_flush;
265 
266 	return 0;
267 }
268 
269 /* Close device */
270 static int hci_uart_close(struct hci_dev *hdev)
271 {
272 	BT_DBG("hdev %p", hdev);
273 
274 	hci_uart_flush(hdev);
275 	hdev->flush = NULL;
276 	return 0;
277 }
278 
279 /* Send frames from HCI layer */
280 static int hci_uart_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
281 {
282 	struct hci_uart *hu = hci_get_drvdata(hdev);
283 
284 	BT_DBG("%s: type %d len %d", hdev->name, hci_skb_pkt_type(skb),
285 	       skb->len);
286 
287 	percpu_down_read(&hu->proto_lock);
288 
289 	if (!test_bit(HCI_UART_PROTO_READY, &hu->flags)) {
290 		percpu_up_read(&hu->proto_lock);
291 		return -EUNATCH;
292 	}
293 
294 	hu->proto->enqueue(hu, skb);
295 	percpu_up_read(&hu->proto_lock);
296 
297 	hci_uart_tx_wakeup(hu);
298 
299 	return 0;
300 }
301 
302 /* Flow control or un-flow control the device */
303 void hci_uart_set_flow_control(struct hci_uart *hu, bool enable)
304 {
305 	struct tty_struct *tty = hu->tty;
306 	struct ktermios ktermios;
307 	int status;
308 	unsigned int set = 0;
309 	unsigned int clear = 0;
310 
311 	if (hu->serdev) {
312 		serdev_device_set_flow_control(hu->serdev, !enable);
313 		serdev_device_set_rts(hu->serdev, !enable);
314 		return;
315 	}
316 
317 	if (enable) {
318 		/* Disable hardware flow control */
319 		ktermios = tty->termios;
320 		ktermios.c_cflag &= ~CRTSCTS;
321 		status = tty_set_termios(tty, &ktermios);
322 		BT_DBG("Disabling hardware flow control: %s",
323 		       status ? "failed" : "success");
324 
325 		/* Clear RTS to prevent the device from sending */
326 		/* Most UARTs need OUT2 to enable interrupts */
327 		status = tty->driver->ops->tiocmget(tty);
328 		BT_DBG("Current tiocm 0x%x", status);
329 
330 		set &= ~(TIOCM_OUT2 | TIOCM_RTS);
331 		clear = ~set;
332 		set &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
333 		       TIOCM_OUT2 | TIOCM_LOOP;
334 		clear &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
335 			 TIOCM_OUT2 | TIOCM_LOOP;
336 		status = tty->driver->ops->tiocmset(tty, set, clear);
337 		BT_DBG("Clearing RTS: %s", status ? "failed" : "success");
338 	} else {
339 		/* Set RTS to allow the device to send again */
340 		status = tty->driver->ops->tiocmget(tty);
341 		BT_DBG("Current tiocm 0x%x", status);
342 
343 		set |= (TIOCM_OUT2 | TIOCM_RTS);
344 		clear = ~set;
345 		set &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
346 		       TIOCM_OUT2 | TIOCM_LOOP;
347 		clear &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
348 			 TIOCM_OUT2 | TIOCM_LOOP;
349 		status = tty->driver->ops->tiocmset(tty, set, clear);
350 		BT_DBG("Setting RTS: %s", status ? "failed" : "success");
351 
352 		/* Re-enable hardware flow control */
353 		ktermios = tty->termios;
354 		ktermios.c_cflag |= CRTSCTS;
355 		status = tty_set_termios(tty, &ktermios);
356 		BT_DBG("Enabling hardware flow control: %s",
357 		       status ? "failed" : "success");
358 	}
359 }
360 
361 void hci_uart_set_speeds(struct hci_uart *hu, unsigned int init_speed,
362 			 unsigned int oper_speed)
363 {
364 	hu->init_speed = init_speed;
365 	hu->oper_speed = oper_speed;
366 }
367 
368 void hci_uart_set_baudrate(struct hci_uart *hu, unsigned int speed)
369 {
370 	struct tty_struct *tty = hu->tty;
371 	struct ktermios ktermios;
372 
373 	ktermios = tty->termios;
374 	ktermios.c_cflag &= ~CBAUD;
375 	tty_termios_encode_baud_rate(&ktermios, speed, speed);
376 
377 	/* tty_set_termios() return not checked as it is always 0 */
378 	tty_set_termios(tty, &ktermios);
379 
380 	BT_DBG("%s: New tty speeds: %d/%d", hu->hdev->name,
381 	       tty->termios.c_ispeed, tty->termios.c_ospeed);
382 }
383 
384 static int hci_uart_setup(struct hci_dev *hdev)
385 {
386 	struct hci_uart *hu = hci_get_drvdata(hdev);
387 	struct hci_rp_read_local_version *ver;
388 	struct sk_buff *skb;
389 	unsigned int speed;
390 	int err;
391 
392 	/* Init speed if any */
393 	if (hu->init_speed)
394 		speed = hu->init_speed;
395 	else if (hu->proto->init_speed)
396 		speed = hu->proto->init_speed;
397 	else
398 		speed = 0;
399 
400 	if (speed)
401 		hci_uart_set_baudrate(hu, speed);
402 
403 	/* Operational speed if any */
404 	if (hu->oper_speed)
405 		speed = hu->oper_speed;
406 	else if (hu->proto->oper_speed)
407 		speed = hu->proto->oper_speed;
408 	else
409 		speed = 0;
410 
411 	if (hu->proto->set_baudrate && speed) {
412 		err = hu->proto->set_baudrate(hu, speed);
413 		if (!err)
414 			hci_uart_set_baudrate(hu, speed);
415 	}
416 
417 	if (hu->proto->setup)
418 		return hu->proto->setup(hu);
419 
420 	if (!test_bit(HCI_UART_VND_DETECT, &hu->hdev_flags))
421 		return 0;
422 
423 	skb = __hci_cmd_sync(hdev, HCI_OP_READ_LOCAL_VERSION, 0, NULL,
424 			     HCI_INIT_TIMEOUT);
425 	if (IS_ERR(skb)) {
426 		BT_ERR("%s: Reading local version information failed (%ld)",
427 		       hdev->name, PTR_ERR(skb));
428 		return 0;
429 	}
430 
431 	if (skb->len != sizeof(*ver)) {
432 		BT_ERR("%s: Event length mismatch for version information",
433 		       hdev->name);
434 		goto done;
435 	}
436 
437 	ver = (struct hci_rp_read_local_version *)skb->data;
438 
439 	switch (le16_to_cpu(ver->manufacturer)) {
440 #ifdef CONFIG_BT_HCIUART_INTEL
441 	case 2:
442 		hdev->set_bdaddr = btintel_set_bdaddr;
443 		btintel_check_bdaddr(hdev);
444 		break;
445 #endif
446 #ifdef CONFIG_BT_HCIUART_BCM
447 	case 15:
448 		hdev->set_bdaddr = btbcm_set_bdaddr;
449 		btbcm_check_bdaddr(hdev);
450 		break;
451 #endif
452 	default:
453 		break;
454 	}
455 
456 done:
457 	kfree_skb(skb);
458 	return 0;
459 }
460 
461 /* ------ LDISC part ------ */
462 /* hci_uart_tty_open
463  *
464  *     Called when line discipline changed to HCI_UART.
465  *
466  * Arguments:
467  *     tty    pointer to tty info structure
468  * Return Value:
469  *     0 if success, otherwise error code
470  */
471 static int hci_uart_tty_open(struct tty_struct *tty)
472 {
473 	struct hci_uart *hu;
474 
475 	BT_DBG("tty %p", tty);
476 
477 	/* Error if the tty has no write op instead of leaving an exploitable
478 	 * hole
479 	 */
480 	if (tty->ops->write == NULL)
481 		return -EOPNOTSUPP;
482 
483 	hu = kzalloc(sizeof(struct hci_uart), GFP_KERNEL);
484 	if (!hu) {
485 		BT_ERR("Can't allocate control structure");
486 		return -ENFILE;
487 	}
488 
489 	tty->disc_data = hu;
490 	hu->tty = tty;
491 	tty->receive_room = 65536;
492 
493 	/* disable alignment support by default */
494 	hu->alignment = 1;
495 	hu->padding = 0;
496 
497 	INIT_WORK(&hu->init_ready, hci_uart_init_work);
498 	INIT_WORK(&hu->write_work, hci_uart_write_work);
499 
500 	percpu_init_rwsem(&hu->proto_lock);
501 
502 	/* Flush any pending characters in the driver */
503 	tty_driver_flush_buffer(tty);
504 
505 	return 0;
506 }
507 
508 /* hci_uart_tty_close()
509  *
510  *    Called when the line discipline is changed to something
511  *    else, the tty is closed, or the tty detects a hangup.
512  */
513 static void hci_uart_tty_close(struct tty_struct *tty)
514 {
515 	struct hci_uart *hu = tty->disc_data;
516 	struct hci_dev *hdev;
517 
518 	BT_DBG("tty %p", tty);
519 
520 	/* Detach from the tty */
521 	tty->disc_data = NULL;
522 
523 	if (!hu)
524 		return;
525 
526 	hdev = hu->hdev;
527 	if (hdev)
528 		hci_uart_close(hdev);
529 
530 	if (test_bit(HCI_UART_PROTO_READY, &hu->flags)) {
531 		percpu_down_write(&hu->proto_lock);
532 		clear_bit(HCI_UART_PROTO_READY, &hu->flags);
533 		percpu_up_write(&hu->proto_lock);
534 
535 		cancel_work_sync(&hu->write_work);
536 
537 		if (hdev) {
538 			if (test_bit(HCI_UART_REGISTERED, &hu->flags))
539 				hci_unregister_dev(hdev);
540 			hci_free_dev(hdev);
541 		}
542 		hu->proto->close(hu);
543 	}
544 	clear_bit(HCI_UART_PROTO_SET, &hu->flags);
545 
546 	percpu_free_rwsem(&hu->proto_lock);
547 
548 	kfree(hu);
549 }
550 
551 /* hci_uart_tty_wakeup()
552  *
553  *    Callback for transmit wakeup. Called when low level
554  *    device driver can accept more send data.
555  *
556  * Arguments:        tty    pointer to associated tty instance data
557  * Return Value:    None
558  */
559 static void hci_uart_tty_wakeup(struct tty_struct *tty)
560 {
561 	struct hci_uart *hu = tty->disc_data;
562 
563 	BT_DBG("");
564 
565 	if (!hu)
566 		return;
567 
568 	clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
569 
570 	if (tty != hu->tty)
571 		return;
572 
573 	if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
574 		hci_uart_tx_wakeup(hu);
575 }
576 
577 /* hci_uart_tty_receive()
578  *
579  *     Called by tty low level driver when receive data is
580  *     available.
581  *
582  * Arguments:  tty          pointer to tty isntance data
583  *             data         pointer to received data
584  *             flags        pointer to flags for data
585  *             count        count of received data in bytes
586  *
587  * Return Value:    None
588  */
589 static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data,
590 				 char *flags, int count)
591 {
592 	struct hci_uart *hu = tty->disc_data;
593 
594 	if (!hu || tty != hu->tty)
595 		return;
596 
597 	percpu_down_read(&hu->proto_lock);
598 
599 	if (!test_bit(HCI_UART_PROTO_READY, &hu->flags)) {
600 		percpu_up_read(&hu->proto_lock);
601 		return;
602 	}
603 
604 	/* It does not need a lock here as it is already protected by a mutex in
605 	 * tty caller
606 	 */
607 	hu->proto->recv(hu, data, count);
608 	percpu_up_read(&hu->proto_lock);
609 
610 	if (hu->hdev)
611 		hu->hdev->stat.byte_rx += count;
612 
613 	tty_unthrottle(tty);
614 }
615 
616 static int hci_uart_register_dev(struct hci_uart *hu)
617 {
618 	struct hci_dev *hdev;
619 
620 	BT_DBG("");
621 
622 	/* Initialize and register HCI device */
623 	hdev = hci_alloc_dev();
624 	if (!hdev) {
625 		BT_ERR("Can't allocate HCI device");
626 		return -ENOMEM;
627 	}
628 
629 	hu->hdev = hdev;
630 
631 	hdev->bus = HCI_UART;
632 	hci_set_drvdata(hdev, hu);
633 
634 	/* Only when vendor specific setup callback is provided, consider
635 	 * the manufacturer information valid. This avoids filling in the
636 	 * value for Ericsson when nothing is specified.
637 	 */
638 	if (hu->proto->setup)
639 		hdev->manufacturer = hu->proto->manufacturer;
640 
641 	hdev->open  = hci_uart_open;
642 	hdev->close = hci_uart_close;
643 	hdev->flush = hci_uart_flush;
644 	hdev->send  = hci_uart_send_frame;
645 	hdev->setup = hci_uart_setup;
646 	SET_HCIDEV_DEV(hdev, hu->tty->dev);
647 
648 	if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags))
649 		set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
650 
651 	if (test_bit(HCI_UART_EXT_CONFIG, &hu->hdev_flags))
652 		set_bit(HCI_QUIRK_EXTERNAL_CONFIG, &hdev->quirks);
653 
654 	if (!test_bit(HCI_UART_RESET_ON_INIT, &hu->hdev_flags))
655 		set_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks);
656 
657 	if (test_bit(HCI_UART_CREATE_AMP, &hu->hdev_flags))
658 		hdev->dev_type = HCI_AMP;
659 	else
660 		hdev->dev_type = HCI_PRIMARY;
661 
662 	if (test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
663 		return 0;
664 
665 	if (hci_register_dev(hdev) < 0) {
666 		BT_ERR("Can't register HCI device");
667 		hu->hdev = NULL;
668 		hci_free_dev(hdev);
669 		return -ENODEV;
670 	}
671 
672 	set_bit(HCI_UART_REGISTERED, &hu->flags);
673 
674 	return 0;
675 }
676 
677 static int hci_uart_set_proto(struct hci_uart *hu, int id)
678 {
679 	const struct hci_uart_proto *p;
680 	int err;
681 
682 	p = hci_uart_get_proto(id);
683 	if (!p)
684 		return -EPROTONOSUPPORT;
685 
686 	err = p->open(hu);
687 	if (err)
688 		return err;
689 
690 	hu->proto = p;
691 	set_bit(HCI_UART_PROTO_READY, &hu->flags);
692 
693 	err = hci_uart_register_dev(hu);
694 	if (err) {
695 		clear_bit(HCI_UART_PROTO_READY, &hu->flags);
696 		p->close(hu);
697 		return err;
698 	}
699 
700 	return 0;
701 }
702 
703 static int hci_uart_set_flags(struct hci_uart *hu, unsigned long flags)
704 {
705 	unsigned long valid_flags = BIT(HCI_UART_RAW_DEVICE) |
706 				    BIT(HCI_UART_RESET_ON_INIT) |
707 				    BIT(HCI_UART_CREATE_AMP) |
708 				    BIT(HCI_UART_INIT_PENDING) |
709 				    BIT(HCI_UART_EXT_CONFIG) |
710 				    BIT(HCI_UART_VND_DETECT);
711 
712 	if (flags & ~valid_flags)
713 		return -EINVAL;
714 
715 	hu->hdev_flags = flags;
716 
717 	return 0;
718 }
719 
720 /* hci_uart_tty_ioctl()
721  *
722  *    Process IOCTL system call for the tty device.
723  *
724  * Arguments:
725  *
726  *    tty        pointer to tty instance data
727  *    file       pointer to open file object for device
728  *    cmd        IOCTL command code
729  *    arg        argument for IOCTL call (cmd dependent)
730  *
731  * Return Value:    Command dependent
732  */
733 static int hci_uart_tty_ioctl(struct tty_struct *tty, struct file *file,
734 			      unsigned int cmd, unsigned long arg)
735 {
736 	struct hci_uart *hu = tty->disc_data;
737 	int err = 0;
738 
739 	BT_DBG("");
740 
741 	/* Verify the status of the device */
742 	if (!hu)
743 		return -EBADF;
744 
745 	switch (cmd) {
746 	case HCIUARTSETPROTO:
747 		if (!test_and_set_bit(HCI_UART_PROTO_SET, &hu->flags)) {
748 			err = hci_uart_set_proto(hu, arg);
749 			if (err)
750 				clear_bit(HCI_UART_PROTO_SET, &hu->flags);
751 		} else
752 			err = -EBUSY;
753 		break;
754 
755 	case HCIUARTGETPROTO:
756 		if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
757 			err = hu->proto->id;
758 		else
759 			err = -EUNATCH;
760 		break;
761 
762 	case HCIUARTGETDEVICE:
763 		if (test_bit(HCI_UART_REGISTERED, &hu->flags))
764 			err = hu->hdev->id;
765 		else
766 			err = -EUNATCH;
767 		break;
768 
769 	case HCIUARTSETFLAGS:
770 		if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
771 			err = -EBUSY;
772 		else
773 			err = hci_uart_set_flags(hu, arg);
774 		break;
775 
776 	case HCIUARTGETFLAGS:
777 		err = hu->hdev_flags;
778 		break;
779 
780 	default:
781 		err = n_tty_ioctl_helper(tty, file, cmd, arg);
782 		break;
783 	}
784 
785 	return err;
786 }
787 
788 /*
789  * We don't provide read/write/poll interface for user space.
790  */
791 static ssize_t hci_uart_tty_read(struct tty_struct *tty, struct file *file,
792 				 unsigned char __user *buf, size_t nr)
793 {
794 	return 0;
795 }
796 
797 static ssize_t hci_uart_tty_write(struct tty_struct *tty, struct file *file,
798 				  const unsigned char *data, size_t count)
799 {
800 	return 0;
801 }
802 
803 static __poll_t hci_uart_tty_poll(struct tty_struct *tty,
804 				      struct file *filp, poll_table *wait)
805 {
806 	return 0;
807 }
808 
809 static int __init hci_uart_init(void)
810 {
811 	static struct tty_ldisc_ops hci_uart_ldisc;
812 	int err;
813 
814 	BT_INFO("HCI UART driver ver %s", VERSION);
815 
816 	/* Register the tty discipline */
817 
818 	memset(&hci_uart_ldisc, 0, sizeof(hci_uart_ldisc));
819 	hci_uart_ldisc.magic		= TTY_LDISC_MAGIC;
820 	hci_uart_ldisc.name		= "n_hci";
821 	hci_uart_ldisc.open		= hci_uart_tty_open;
822 	hci_uart_ldisc.close		= hci_uart_tty_close;
823 	hci_uart_ldisc.read		= hci_uart_tty_read;
824 	hci_uart_ldisc.write		= hci_uart_tty_write;
825 	hci_uart_ldisc.ioctl		= hci_uart_tty_ioctl;
826 	hci_uart_ldisc.compat_ioctl	= hci_uart_tty_ioctl;
827 	hci_uart_ldisc.poll		= hci_uart_tty_poll;
828 	hci_uart_ldisc.receive_buf	= hci_uart_tty_receive;
829 	hci_uart_ldisc.write_wakeup	= hci_uart_tty_wakeup;
830 	hci_uart_ldisc.owner		= THIS_MODULE;
831 
832 	err = tty_register_ldisc(N_HCI, &hci_uart_ldisc);
833 	if (err) {
834 		BT_ERR("HCI line discipline registration failed. (%d)", err);
835 		return err;
836 	}
837 
838 #ifdef CONFIG_BT_HCIUART_H4
839 	h4_init();
840 #endif
841 #ifdef CONFIG_BT_HCIUART_BCSP
842 	bcsp_init();
843 #endif
844 #ifdef CONFIG_BT_HCIUART_LL
845 	ll_init();
846 #endif
847 #ifdef CONFIG_BT_HCIUART_ATH3K
848 	ath_init();
849 #endif
850 #ifdef CONFIG_BT_HCIUART_3WIRE
851 	h5_init();
852 #endif
853 #ifdef CONFIG_BT_HCIUART_INTEL
854 	intel_init();
855 #endif
856 #ifdef CONFIG_BT_HCIUART_BCM
857 	bcm_init();
858 #endif
859 #ifdef CONFIG_BT_HCIUART_QCA
860 	qca_init();
861 #endif
862 #ifdef CONFIG_BT_HCIUART_AG6XX
863 	ag6xx_init();
864 #endif
865 #ifdef CONFIG_BT_HCIUART_MRVL
866 	mrvl_init();
867 #endif
868 
869 	return 0;
870 }
871 
872 static void __exit hci_uart_exit(void)
873 {
874 	int err;
875 
876 #ifdef CONFIG_BT_HCIUART_H4
877 	h4_deinit();
878 #endif
879 #ifdef CONFIG_BT_HCIUART_BCSP
880 	bcsp_deinit();
881 #endif
882 #ifdef CONFIG_BT_HCIUART_LL
883 	ll_deinit();
884 #endif
885 #ifdef CONFIG_BT_HCIUART_ATH3K
886 	ath_deinit();
887 #endif
888 #ifdef CONFIG_BT_HCIUART_3WIRE
889 	h5_deinit();
890 #endif
891 #ifdef CONFIG_BT_HCIUART_INTEL
892 	intel_deinit();
893 #endif
894 #ifdef CONFIG_BT_HCIUART_BCM
895 	bcm_deinit();
896 #endif
897 #ifdef CONFIG_BT_HCIUART_QCA
898 	qca_deinit();
899 #endif
900 #ifdef CONFIG_BT_HCIUART_AG6XX
901 	ag6xx_deinit();
902 #endif
903 #ifdef CONFIG_BT_HCIUART_MRVL
904 	mrvl_deinit();
905 #endif
906 
907 	/* Release tty registration of line discipline */
908 	err = tty_unregister_ldisc(N_HCI);
909 	if (err)
910 		BT_ERR("Can't unregister HCI line discipline (%d)", err);
911 }
912 
913 module_init(hci_uart_init);
914 module_exit(hci_uart_exit);
915 
916 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
917 MODULE_DESCRIPTION("Bluetooth HCI UART driver ver " VERSION);
918 MODULE_VERSION(VERSION);
919 MODULE_LICENSE("GPL");
920 MODULE_ALIAS_LDISC(N_HCI);
921