xref: /openbmc/linux/drivers/bluetooth/hci_ldisc.c (revision b830f94f)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *
4  *  Bluetooth HCI UART driver
5  *
6  *  Copyright (C) 2000-2001  Qualcomm Incorporated
7  *  Copyright (C) 2002-2003  Maxim Krasnyansky <maxk@qualcomm.com>
8  *  Copyright (C) 2004-2005  Marcel Holtmann <marcel@holtmann.org>
9  */
10 
11 #include <linux/module.h>
12 
13 #include <linux/kernel.h>
14 #include <linux/init.h>
15 #include <linux/types.h>
16 #include <linux/fcntl.h>
17 #include <linux/interrupt.h>
18 #include <linux/ptrace.h>
19 #include <linux/poll.h>
20 
21 #include <linux/slab.h>
22 #include <linux/tty.h>
23 #include <linux/errno.h>
24 #include <linux/string.h>
25 #include <linux/signal.h>
26 #include <linux/ioctl.h>
27 #include <linux/skbuff.h>
28 #include <linux/firmware.h>
29 #include <linux/serdev.h>
30 
31 #include <net/bluetooth/bluetooth.h>
32 #include <net/bluetooth/hci_core.h>
33 
34 #include "btintel.h"
35 #include "btbcm.h"
36 #include "hci_uart.h"
37 
38 #define VERSION "2.3"
39 
40 static const struct hci_uart_proto *hup[HCI_UART_MAX_PROTO];
41 
42 int hci_uart_register_proto(const struct hci_uart_proto *p)
43 {
44 	if (p->id >= HCI_UART_MAX_PROTO)
45 		return -EINVAL;
46 
47 	if (hup[p->id])
48 		return -EEXIST;
49 
50 	hup[p->id] = p;
51 
52 	BT_INFO("HCI UART protocol %s registered", p->name);
53 
54 	return 0;
55 }
56 
57 int hci_uart_unregister_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 -EINVAL;
64 
65 	hup[p->id] = NULL;
66 
67 	return 0;
68 }
69 
70 static const struct hci_uart_proto *hci_uart_get_proto(unsigned int id)
71 {
72 	if (id >= HCI_UART_MAX_PROTO)
73 		return NULL;
74 
75 	return hup[id];
76 }
77 
78 static inline void hci_uart_tx_complete(struct hci_uart *hu, int pkt_type)
79 {
80 	struct hci_dev *hdev = hu->hdev;
81 
82 	/* Update HCI stat counters */
83 	switch (pkt_type) {
84 	case HCI_COMMAND_PKT:
85 		hdev->stat.cmd_tx++;
86 		break;
87 
88 	case HCI_ACLDATA_PKT:
89 		hdev->stat.acl_tx++;
90 		break;
91 
92 	case HCI_SCODATA_PKT:
93 		hdev->stat.sco_tx++;
94 		break;
95 	}
96 }
97 
98 static inline struct sk_buff *hci_uart_dequeue(struct hci_uart *hu)
99 {
100 	struct sk_buff *skb = hu->tx_skb;
101 
102 	if (!skb) {
103 		percpu_down_read(&hu->proto_lock);
104 
105 		if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
106 			skb = hu->proto->dequeue(hu);
107 
108 		percpu_up_read(&hu->proto_lock);
109 	} else {
110 		hu->tx_skb = NULL;
111 	}
112 
113 	return skb;
114 }
115 
116 int hci_uart_tx_wakeup(struct hci_uart *hu)
117 {
118 	/* This may be called in an IRQ context, so we can't sleep. Therefore
119 	 * we try to acquire the lock only, and if that fails we assume the
120 	 * tty is being closed because that is the only time the write lock is
121 	 * acquired. If, however, at some point in the future the write lock
122 	 * is also acquired in other situations, then this must be revisited.
123 	 */
124 	if (!percpu_down_read_trylock(&hu->proto_lock))
125 		return 0;
126 
127 	if (!test_bit(HCI_UART_PROTO_READY, &hu->flags))
128 		goto no_schedule;
129 
130 	if (test_and_set_bit(HCI_UART_SENDING, &hu->tx_state)) {
131 		set_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
132 		goto no_schedule;
133 	}
134 
135 	BT_DBG("");
136 
137 	schedule_work(&hu->write_work);
138 
139 no_schedule:
140 	percpu_up_read(&hu->proto_lock);
141 
142 	return 0;
143 }
144 EXPORT_SYMBOL_GPL(hci_uart_tx_wakeup);
145 
146 static void hci_uart_write_work(struct work_struct *work)
147 {
148 	struct hci_uart *hu = container_of(work, struct hci_uart, write_work);
149 	struct tty_struct *tty = hu->tty;
150 	struct hci_dev *hdev = hu->hdev;
151 	struct sk_buff *skb;
152 
153 	/* REVISIT: should we cope with bad skbs or ->write() returning
154 	 * and error value ?
155 	 */
156 
157 restart:
158 	clear_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
159 
160 	while ((skb = hci_uart_dequeue(hu))) {
161 		int len;
162 
163 		set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
164 		len = tty->ops->write(tty, skb->data, skb->len);
165 		hdev->stat.byte_tx += len;
166 
167 		skb_pull(skb, len);
168 		if (skb->len) {
169 			hu->tx_skb = skb;
170 			break;
171 		}
172 
173 		hci_uart_tx_complete(hu, hci_skb_pkt_type(skb));
174 		kfree_skb(skb);
175 	}
176 
177 	if (test_bit(HCI_UART_TX_WAKEUP, &hu->tx_state))
178 		goto restart;
179 
180 	clear_bit(HCI_UART_SENDING, &hu->tx_state);
181 	wake_up_bit(&hu->tx_state, HCI_UART_SENDING);
182 }
183 
184 void hci_uart_init_work(struct work_struct *work)
185 {
186 	struct hci_uart *hu = container_of(work, struct hci_uart, init_ready);
187 	int err;
188 	struct hci_dev *hdev;
189 
190 	if (!test_and_clear_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
191 		return;
192 
193 	err = hci_register_dev(hu->hdev);
194 	if (err < 0) {
195 		BT_ERR("Can't register HCI device");
196 		clear_bit(HCI_UART_PROTO_READY, &hu->flags);
197 		hu->proto->close(hu);
198 		hdev = hu->hdev;
199 		hu->hdev = NULL;
200 		hci_free_dev(hdev);
201 		return;
202 	}
203 
204 	set_bit(HCI_UART_REGISTERED, &hu->flags);
205 }
206 
207 int hci_uart_init_ready(struct hci_uart *hu)
208 {
209 	if (!test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
210 		return -EALREADY;
211 
212 	schedule_work(&hu->init_ready);
213 
214 	return 0;
215 }
216 
217 int hci_uart_wait_until_sent(struct hci_uart *hu)
218 {
219 	return wait_on_bit_timeout(&hu->tx_state, HCI_UART_SENDING,
220 				   TASK_INTERRUPTIBLE,
221 				   msecs_to_jiffies(2000));
222 }
223 
224 /* ------- Interface to HCI layer ------ */
225 /* Reset device */
226 static int hci_uart_flush(struct hci_dev *hdev)
227 {
228 	struct hci_uart *hu  = hci_get_drvdata(hdev);
229 	struct tty_struct *tty = hu->tty;
230 
231 	BT_DBG("hdev %p tty %p", hdev, tty);
232 
233 	if (hu->tx_skb) {
234 		kfree_skb(hu->tx_skb); hu->tx_skb = NULL;
235 	}
236 
237 	/* Flush any pending characters in the driver and discipline. */
238 	tty_ldisc_flush(tty);
239 	tty_driver_flush_buffer(tty);
240 
241 	percpu_down_read(&hu->proto_lock);
242 
243 	if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
244 		hu->proto->flush(hu);
245 
246 	percpu_up_read(&hu->proto_lock);
247 
248 	return 0;
249 }
250 
251 /* Initialize device */
252 static int hci_uart_open(struct hci_dev *hdev)
253 {
254 	BT_DBG("%s %p", hdev->name, hdev);
255 
256 	/* Undo clearing this from hci_uart_close() */
257 	hdev->flush = hci_uart_flush;
258 
259 	return 0;
260 }
261 
262 /* Close device */
263 static int hci_uart_close(struct hci_dev *hdev)
264 {
265 	BT_DBG("hdev %p", hdev);
266 
267 	hci_uart_flush(hdev);
268 	hdev->flush = NULL;
269 	return 0;
270 }
271 
272 /* Send frames from HCI layer */
273 static int hci_uart_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
274 {
275 	struct hci_uart *hu = hci_get_drvdata(hdev);
276 
277 	BT_DBG("%s: type %d len %d", hdev->name, hci_skb_pkt_type(skb),
278 	       skb->len);
279 
280 	percpu_down_read(&hu->proto_lock);
281 
282 	if (!test_bit(HCI_UART_PROTO_READY, &hu->flags)) {
283 		percpu_up_read(&hu->proto_lock);
284 		return -EUNATCH;
285 	}
286 
287 	hu->proto->enqueue(hu, skb);
288 	percpu_up_read(&hu->proto_lock);
289 
290 	hci_uart_tx_wakeup(hu);
291 
292 	return 0;
293 }
294 
295 /* Flow control or un-flow control the device */
296 void hci_uart_set_flow_control(struct hci_uart *hu, bool enable)
297 {
298 	struct tty_struct *tty = hu->tty;
299 	struct ktermios ktermios;
300 	int status;
301 	unsigned int set = 0;
302 	unsigned int clear = 0;
303 
304 	if (hu->serdev) {
305 		serdev_device_set_flow_control(hu->serdev, !enable);
306 		serdev_device_set_rts(hu->serdev, !enable);
307 		return;
308 	}
309 
310 	if (enable) {
311 		/* Disable hardware flow control */
312 		ktermios = tty->termios;
313 		ktermios.c_cflag &= ~CRTSCTS;
314 		status = tty_set_termios(tty, &ktermios);
315 		BT_DBG("Disabling hardware flow control: %s",
316 		       status ? "failed" : "success");
317 
318 		/* Clear RTS to prevent the device from sending */
319 		/* Most UARTs need OUT2 to enable interrupts */
320 		status = tty->driver->ops->tiocmget(tty);
321 		BT_DBG("Current tiocm 0x%x", status);
322 
323 		set &= ~(TIOCM_OUT2 | TIOCM_RTS);
324 		clear = ~set;
325 		set &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
326 		       TIOCM_OUT2 | TIOCM_LOOP;
327 		clear &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
328 			 TIOCM_OUT2 | TIOCM_LOOP;
329 		status = tty->driver->ops->tiocmset(tty, set, clear);
330 		BT_DBG("Clearing RTS: %s", status ? "failed" : "success");
331 	} else {
332 		/* Set RTS to allow the device to send again */
333 		status = tty->driver->ops->tiocmget(tty);
334 		BT_DBG("Current tiocm 0x%x", status);
335 
336 		set |= (TIOCM_OUT2 | TIOCM_RTS);
337 		clear = ~set;
338 		set &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
339 		       TIOCM_OUT2 | TIOCM_LOOP;
340 		clear &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
341 			 TIOCM_OUT2 | TIOCM_LOOP;
342 		status = tty->driver->ops->tiocmset(tty, set, clear);
343 		BT_DBG("Setting RTS: %s", status ? "failed" : "success");
344 
345 		/* Re-enable hardware flow control */
346 		ktermios = tty->termios;
347 		ktermios.c_cflag |= CRTSCTS;
348 		status = tty_set_termios(tty, &ktermios);
349 		BT_DBG("Enabling hardware flow control: %s",
350 		       status ? "failed" : "success");
351 	}
352 }
353 
354 void hci_uart_set_speeds(struct hci_uart *hu, unsigned int init_speed,
355 			 unsigned int oper_speed)
356 {
357 	hu->init_speed = init_speed;
358 	hu->oper_speed = oper_speed;
359 }
360 
361 void hci_uart_set_baudrate(struct hci_uart *hu, unsigned int speed)
362 {
363 	struct tty_struct *tty = hu->tty;
364 	struct ktermios ktermios;
365 
366 	ktermios = tty->termios;
367 	ktermios.c_cflag &= ~CBAUD;
368 	tty_termios_encode_baud_rate(&ktermios, speed, speed);
369 
370 	/* tty_set_termios() return not checked as it is always 0 */
371 	tty_set_termios(tty, &ktermios);
372 
373 	BT_DBG("%s: New tty speeds: %d/%d", hu->hdev->name,
374 	       tty->termios.c_ispeed, tty->termios.c_ospeed);
375 }
376 
377 static int hci_uart_setup(struct hci_dev *hdev)
378 {
379 	struct hci_uart *hu = hci_get_drvdata(hdev);
380 	struct hci_rp_read_local_version *ver;
381 	struct sk_buff *skb;
382 	unsigned int speed;
383 	int err;
384 
385 	/* Init speed if any */
386 	if (hu->init_speed)
387 		speed = hu->init_speed;
388 	else if (hu->proto->init_speed)
389 		speed = hu->proto->init_speed;
390 	else
391 		speed = 0;
392 
393 	if (speed)
394 		hci_uart_set_baudrate(hu, speed);
395 
396 	/* Operational speed if any */
397 	if (hu->oper_speed)
398 		speed = hu->oper_speed;
399 	else if (hu->proto->oper_speed)
400 		speed = hu->proto->oper_speed;
401 	else
402 		speed = 0;
403 
404 	if (hu->proto->set_baudrate && speed) {
405 		err = hu->proto->set_baudrate(hu, speed);
406 		if (!err)
407 			hci_uart_set_baudrate(hu, speed);
408 	}
409 
410 	if (hu->proto->setup)
411 		return hu->proto->setup(hu);
412 
413 	if (!test_bit(HCI_UART_VND_DETECT, &hu->hdev_flags))
414 		return 0;
415 
416 	skb = __hci_cmd_sync(hdev, HCI_OP_READ_LOCAL_VERSION, 0, NULL,
417 			     HCI_INIT_TIMEOUT);
418 	if (IS_ERR(skb)) {
419 		BT_ERR("%s: Reading local version information failed (%ld)",
420 		       hdev->name, PTR_ERR(skb));
421 		return 0;
422 	}
423 
424 	if (skb->len != sizeof(*ver)) {
425 		BT_ERR("%s: Event length mismatch for version information",
426 		       hdev->name);
427 		goto done;
428 	}
429 
430 	ver = (struct hci_rp_read_local_version *)skb->data;
431 
432 	switch (le16_to_cpu(ver->manufacturer)) {
433 #ifdef CONFIG_BT_HCIUART_INTEL
434 	case 2:
435 		hdev->set_bdaddr = btintel_set_bdaddr;
436 		btintel_check_bdaddr(hdev);
437 		break;
438 #endif
439 #ifdef CONFIG_BT_HCIUART_BCM
440 	case 15:
441 		hdev->set_bdaddr = btbcm_set_bdaddr;
442 		btbcm_check_bdaddr(hdev);
443 		break;
444 #endif
445 	default:
446 		break;
447 	}
448 
449 done:
450 	kfree_skb(skb);
451 	return 0;
452 }
453 
454 /* ------ LDISC part ------ */
455 /* hci_uart_tty_open
456  *
457  *     Called when line discipline changed to HCI_UART.
458  *
459  * Arguments:
460  *     tty    pointer to tty info structure
461  * Return Value:
462  *     0 if success, otherwise error code
463  */
464 static int hci_uart_tty_open(struct tty_struct *tty)
465 {
466 	struct hci_uart *hu;
467 
468 	BT_DBG("tty %p", tty);
469 
470 	/* Error if the tty has no write op instead of leaving an exploitable
471 	 * hole
472 	 */
473 	if (tty->ops->write == NULL)
474 		return -EOPNOTSUPP;
475 
476 	hu = kzalloc(sizeof(struct hci_uart), GFP_KERNEL);
477 	if (!hu) {
478 		BT_ERR("Can't allocate control structure");
479 		return -ENFILE;
480 	}
481 
482 	tty->disc_data = hu;
483 	hu->tty = tty;
484 	tty->receive_room = 65536;
485 
486 	/* disable alignment support by default */
487 	hu->alignment = 1;
488 	hu->padding = 0;
489 
490 	INIT_WORK(&hu->init_ready, hci_uart_init_work);
491 	INIT_WORK(&hu->write_work, hci_uart_write_work);
492 
493 	percpu_init_rwsem(&hu->proto_lock);
494 
495 	/* Flush any pending characters in the driver */
496 	tty_driver_flush_buffer(tty);
497 
498 	return 0;
499 }
500 
501 /* hci_uart_tty_close()
502  *
503  *    Called when the line discipline is changed to something
504  *    else, the tty is closed, or the tty detects a hangup.
505  */
506 static void hci_uart_tty_close(struct tty_struct *tty)
507 {
508 	struct hci_uart *hu = tty->disc_data;
509 	struct hci_dev *hdev;
510 
511 	BT_DBG("tty %p", tty);
512 
513 	/* Detach from the tty */
514 	tty->disc_data = NULL;
515 
516 	if (!hu)
517 		return;
518 
519 	hdev = hu->hdev;
520 	if (hdev)
521 		hci_uart_close(hdev);
522 
523 	if (test_bit(HCI_UART_PROTO_READY, &hu->flags)) {
524 		percpu_down_write(&hu->proto_lock);
525 		clear_bit(HCI_UART_PROTO_READY, &hu->flags);
526 		percpu_up_write(&hu->proto_lock);
527 
528 		cancel_work_sync(&hu->write_work);
529 
530 		if (hdev) {
531 			if (test_bit(HCI_UART_REGISTERED, &hu->flags))
532 				hci_unregister_dev(hdev);
533 			hci_free_dev(hdev);
534 		}
535 		hu->proto->close(hu);
536 	}
537 	clear_bit(HCI_UART_PROTO_SET, &hu->flags);
538 
539 	percpu_free_rwsem(&hu->proto_lock);
540 
541 	kfree(hu);
542 }
543 
544 /* hci_uart_tty_wakeup()
545  *
546  *    Callback for transmit wakeup. Called when low level
547  *    device driver can accept more send data.
548  *
549  * Arguments:        tty    pointer to associated tty instance data
550  * Return Value:    None
551  */
552 static void hci_uart_tty_wakeup(struct tty_struct *tty)
553 {
554 	struct hci_uart *hu = tty->disc_data;
555 
556 	BT_DBG("");
557 
558 	if (!hu)
559 		return;
560 
561 	clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
562 
563 	if (tty != hu->tty)
564 		return;
565 
566 	if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
567 		hci_uart_tx_wakeup(hu);
568 }
569 
570 /* hci_uart_tty_receive()
571  *
572  *     Called by tty low level driver when receive data is
573  *     available.
574  *
575  * Arguments:  tty          pointer to tty isntance data
576  *             data         pointer to received data
577  *             flags        pointer to flags for data
578  *             count        count of received data in bytes
579  *
580  * Return Value:    None
581  */
582 static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data,
583 				 char *flags, int count)
584 {
585 	struct hci_uart *hu = tty->disc_data;
586 
587 	if (!hu || tty != hu->tty)
588 		return;
589 
590 	percpu_down_read(&hu->proto_lock);
591 
592 	if (!test_bit(HCI_UART_PROTO_READY, &hu->flags)) {
593 		percpu_up_read(&hu->proto_lock);
594 		return;
595 	}
596 
597 	/* It does not need a lock here as it is already protected by a mutex in
598 	 * tty caller
599 	 */
600 	hu->proto->recv(hu, data, count);
601 	percpu_up_read(&hu->proto_lock);
602 
603 	if (hu->hdev)
604 		hu->hdev->stat.byte_rx += count;
605 
606 	tty_unthrottle(tty);
607 }
608 
609 static int hci_uart_register_dev(struct hci_uart *hu)
610 {
611 	struct hci_dev *hdev;
612 	int err;
613 
614 	BT_DBG("");
615 
616 	/* Initialize and register HCI device */
617 	hdev = hci_alloc_dev();
618 	if (!hdev) {
619 		BT_ERR("Can't allocate HCI device");
620 		return -ENOMEM;
621 	}
622 
623 	hu->hdev = hdev;
624 
625 	hdev->bus = HCI_UART;
626 	hci_set_drvdata(hdev, hu);
627 
628 	/* Only when vendor specific setup callback is provided, consider
629 	 * the manufacturer information valid. This avoids filling in the
630 	 * value for Ericsson when nothing is specified.
631 	 */
632 	if (hu->proto->setup)
633 		hdev->manufacturer = hu->proto->manufacturer;
634 
635 	hdev->open  = hci_uart_open;
636 	hdev->close = hci_uart_close;
637 	hdev->flush = hci_uart_flush;
638 	hdev->send  = hci_uart_send_frame;
639 	hdev->setup = hci_uart_setup;
640 	SET_HCIDEV_DEV(hdev, hu->tty->dev);
641 
642 	if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags))
643 		set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
644 
645 	if (test_bit(HCI_UART_EXT_CONFIG, &hu->hdev_flags))
646 		set_bit(HCI_QUIRK_EXTERNAL_CONFIG, &hdev->quirks);
647 
648 	if (!test_bit(HCI_UART_RESET_ON_INIT, &hu->hdev_flags))
649 		set_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks);
650 
651 	if (test_bit(HCI_UART_CREATE_AMP, &hu->hdev_flags))
652 		hdev->dev_type = HCI_AMP;
653 	else
654 		hdev->dev_type = HCI_PRIMARY;
655 
656 	/* Only call open() for the protocol after hdev is fully initialized as
657 	 * open() (or a timer/workqueue it starts) may attempt to reference it.
658 	 */
659 	err = hu->proto->open(hu);
660 	if (err) {
661 		hu->hdev = NULL;
662 		hci_free_dev(hdev);
663 		return err;
664 	}
665 
666 	if (test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
667 		return 0;
668 
669 	if (hci_register_dev(hdev) < 0) {
670 		BT_ERR("Can't register HCI device");
671 		hu->proto->close(hu);
672 		hu->hdev = NULL;
673 		hci_free_dev(hdev);
674 		return -ENODEV;
675 	}
676 
677 	set_bit(HCI_UART_REGISTERED, &hu->flags);
678 
679 	return 0;
680 }
681 
682 static int hci_uart_set_proto(struct hci_uart *hu, int id)
683 {
684 	const struct hci_uart_proto *p;
685 	int err;
686 
687 	p = hci_uart_get_proto(id);
688 	if (!p)
689 		return -EPROTONOSUPPORT;
690 
691 	hu->proto = p;
692 
693 	err = hci_uart_register_dev(hu);
694 	if (err) {
695 		return err;
696 	}
697 
698 	set_bit(HCI_UART_PROTO_READY, &hu->flags);
699 	return 0;
700 }
701 
702 static int hci_uart_set_flags(struct hci_uart *hu, unsigned long flags)
703 {
704 	unsigned long valid_flags = BIT(HCI_UART_RAW_DEVICE) |
705 				    BIT(HCI_UART_RESET_ON_INIT) |
706 				    BIT(HCI_UART_CREATE_AMP) |
707 				    BIT(HCI_UART_INIT_PENDING) |
708 				    BIT(HCI_UART_EXT_CONFIG) |
709 				    BIT(HCI_UART_VND_DETECT);
710 
711 	if (flags & ~valid_flags)
712 		return -EINVAL;
713 
714 	hu->hdev_flags = flags;
715 
716 	return 0;
717 }
718 
719 /* hci_uart_tty_ioctl()
720  *
721  *    Process IOCTL system call for the tty device.
722  *
723  * Arguments:
724  *
725  *    tty        pointer to tty instance data
726  *    file       pointer to open file object for device
727  *    cmd        IOCTL command code
728  *    arg        argument for IOCTL call (cmd dependent)
729  *
730  * Return Value:    Command dependent
731  */
732 static int hci_uart_tty_ioctl(struct tty_struct *tty, struct file *file,
733 			      unsigned int cmd, unsigned long arg)
734 {
735 	struct hci_uart *hu = tty->disc_data;
736 	int err = 0;
737 
738 	BT_DBG("");
739 
740 	/* Verify the status of the device */
741 	if (!hu)
742 		return -EBADF;
743 
744 	switch (cmd) {
745 	case HCIUARTSETPROTO:
746 		if (!test_and_set_bit(HCI_UART_PROTO_SET, &hu->flags)) {
747 			err = hci_uart_set_proto(hu, arg);
748 			if (err)
749 				clear_bit(HCI_UART_PROTO_SET, &hu->flags);
750 		} else
751 			err = -EBUSY;
752 		break;
753 
754 	case HCIUARTGETPROTO:
755 		if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
756 			err = hu->proto->id;
757 		else
758 			err = -EUNATCH;
759 		break;
760 
761 	case HCIUARTGETDEVICE:
762 		if (test_bit(HCI_UART_REGISTERED, &hu->flags))
763 			err = hu->hdev->id;
764 		else
765 			err = -EUNATCH;
766 		break;
767 
768 	case HCIUARTSETFLAGS:
769 		if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
770 			err = -EBUSY;
771 		else
772 			err = hci_uart_set_flags(hu, arg);
773 		break;
774 
775 	case HCIUARTGETFLAGS:
776 		err = hu->hdev_flags;
777 		break;
778 
779 	default:
780 		err = n_tty_ioctl_helper(tty, file, cmd, arg);
781 		break;
782 	}
783 
784 	return err;
785 }
786 
787 /*
788  * We don't provide read/write/poll interface for user space.
789  */
790 static ssize_t hci_uart_tty_read(struct tty_struct *tty, struct file *file,
791 				 unsigned char __user *buf, size_t nr)
792 {
793 	return 0;
794 }
795 
796 static ssize_t hci_uart_tty_write(struct tty_struct *tty, struct file *file,
797 				  const unsigned char *data, size_t count)
798 {
799 	return 0;
800 }
801 
802 static __poll_t hci_uart_tty_poll(struct tty_struct *tty,
803 				      struct file *filp, poll_table *wait)
804 {
805 	return 0;
806 }
807 
808 static int __init hci_uart_init(void)
809 {
810 	static struct tty_ldisc_ops hci_uart_ldisc;
811 	int err;
812 
813 	BT_INFO("HCI UART driver ver %s", VERSION);
814 
815 	/* Register the tty discipline */
816 
817 	memset(&hci_uart_ldisc, 0, sizeof(hci_uart_ldisc));
818 	hci_uart_ldisc.magic		= TTY_LDISC_MAGIC;
819 	hci_uart_ldisc.name		= "n_hci";
820 	hci_uart_ldisc.open		= hci_uart_tty_open;
821 	hci_uart_ldisc.close		= hci_uart_tty_close;
822 	hci_uart_ldisc.read		= hci_uart_tty_read;
823 	hci_uart_ldisc.write		= hci_uart_tty_write;
824 	hci_uart_ldisc.ioctl		= hci_uart_tty_ioctl;
825 	hci_uart_ldisc.compat_ioctl	= hci_uart_tty_ioctl;
826 	hci_uart_ldisc.poll		= hci_uart_tty_poll;
827 	hci_uart_ldisc.receive_buf	= hci_uart_tty_receive;
828 	hci_uart_ldisc.write_wakeup	= hci_uart_tty_wakeup;
829 	hci_uart_ldisc.owner		= THIS_MODULE;
830 
831 	err = tty_register_ldisc(N_HCI, &hci_uart_ldisc);
832 	if (err) {
833 		BT_ERR("HCI line discipline registration failed. (%d)", err);
834 		return err;
835 	}
836 
837 #ifdef CONFIG_BT_HCIUART_H4
838 	h4_init();
839 #endif
840 #ifdef CONFIG_BT_HCIUART_BCSP
841 	bcsp_init();
842 #endif
843 #ifdef CONFIG_BT_HCIUART_LL
844 	ll_init();
845 #endif
846 #ifdef CONFIG_BT_HCIUART_ATH3K
847 	ath_init();
848 #endif
849 #ifdef CONFIG_BT_HCIUART_3WIRE
850 	h5_init();
851 #endif
852 #ifdef CONFIG_BT_HCIUART_INTEL
853 	intel_init();
854 #endif
855 #ifdef CONFIG_BT_HCIUART_BCM
856 	bcm_init();
857 #endif
858 #ifdef CONFIG_BT_HCIUART_QCA
859 	qca_init();
860 #endif
861 #ifdef CONFIG_BT_HCIUART_AG6XX
862 	ag6xx_init();
863 #endif
864 #ifdef CONFIG_BT_HCIUART_MRVL
865 	mrvl_init();
866 #endif
867 
868 	return 0;
869 }
870 
871 static void __exit hci_uart_exit(void)
872 {
873 	int err;
874 
875 #ifdef CONFIG_BT_HCIUART_H4
876 	h4_deinit();
877 #endif
878 #ifdef CONFIG_BT_HCIUART_BCSP
879 	bcsp_deinit();
880 #endif
881 #ifdef CONFIG_BT_HCIUART_LL
882 	ll_deinit();
883 #endif
884 #ifdef CONFIG_BT_HCIUART_ATH3K
885 	ath_deinit();
886 #endif
887 #ifdef CONFIG_BT_HCIUART_3WIRE
888 	h5_deinit();
889 #endif
890 #ifdef CONFIG_BT_HCIUART_INTEL
891 	intel_deinit();
892 #endif
893 #ifdef CONFIG_BT_HCIUART_BCM
894 	bcm_deinit();
895 #endif
896 #ifdef CONFIG_BT_HCIUART_QCA
897 	qca_deinit();
898 #endif
899 #ifdef CONFIG_BT_HCIUART_AG6XX
900 	ag6xx_deinit();
901 #endif
902 #ifdef CONFIG_BT_HCIUART_MRVL
903 	mrvl_deinit();
904 #endif
905 
906 	/* Release tty registration of line discipline */
907 	err = tty_unregister_ldisc(N_HCI);
908 	if (err)
909 		BT_ERR("Can't unregister HCI line discipline (%d)", err);
910 }
911 
912 module_init(hci_uart_init);
913 module_exit(hci_uart_exit);
914 
915 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
916 MODULE_DESCRIPTION("Bluetooth HCI UART driver ver " VERSION);
917 MODULE_VERSION(VERSION);
918 MODULE_LICENSE("GPL");
919 MODULE_ALIAS_LDISC(N_HCI);
920