xref: /linux/drivers/bluetooth/hci_ldisc.c (revision 9410645520e9b820069761f3450ef6661418e279)
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 
hci_uart_register_proto(const struct hci_uart_proto * p)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 
hci_uart_unregister_proto(const struct hci_uart_proto * p)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 
hci_uart_get_proto(unsigned int id)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 
hci_uart_tx_complete(struct hci_uart * hu,int pkt_type)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 
hci_uart_dequeue(struct hci_uart * hu)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 
hci_uart_tx_wakeup(struct hci_uart * hu)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 	set_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
131 	if (test_and_set_bit(HCI_UART_SENDING, &hu->tx_state))
132 		goto no_schedule;
133 
134 	BT_DBG("");
135 
136 	schedule_work(&hu->write_work);
137 
138 no_schedule:
139 	percpu_up_read(&hu->proto_lock);
140 
141 	return 0;
142 }
143 EXPORT_SYMBOL_GPL(hci_uart_tx_wakeup);
144 
hci_uart_write_work(struct work_struct * work)145 static void hci_uart_write_work(struct work_struct *work)
146 {
147 	struct hci_uart *hu = container_of(work, struct hci_uart, write_work);
148 	struct tty_struct *tty = hu->tty;
149 	struct hci_dev *hdev = hu->hdev;
150 	struct sk_buff *skb;
151 
152 	/* REVISIT: should we cope with bad skbs or ->write() returning
153 	 * and error value ?
154 	 */
155 
156 restart:
157 	clear_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
158 
159 	while ((skb = hci_uart_dequeue(hu))) {
160 		int len;
161 
162 		set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
163 		len = tty->ops->write(tty, skb->data, skb->len);
164 		hdev->stat.byte_tx += len;
165 
166 		skb_pull(skb, len);
167 		if (skb->len) {
168 			hu->tx_skb = skb;
169 			break;
170 		}
171 
172 		hci_uart_tx_complete(hu, hci_skb_pkt_type(skb));
173 		kfree_skb(skb);
174 	}
175 
176 	clear_bit(HCI_UART_SENDING, &hu->tx_state);
177 	if (test_bit(HCI_UART_TX_WAKEUP, &hu->tx_state))
178 		goto restart;
179 
180 	wake_up_bit(&hu->tx_state, HCI_UART_SENDING);
181 }
182 
hci_uart_init_work(struct work_struct * work)183 void hci_uart_init_work(struct work_struct *work)
184 {
185 	struct hci_uart *hu = container_of(work, struct hci_uart, init_ready);
186 	int err;
187 	struct hci_dev *hdev;
188 
189 	if (!test_and_clear_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
190 		return;
191 
192 	err = hci_register_dev(hu->hdev);
193 	if (err < 0) {
194 		BT_ERR("Can't register HCI device");
195 		clear_bit(HCI_UART_PROTO_READY, &hu->flags);
196 		hu->proto->close(hu);
197 		hdev = hu->hdev;
198 		hu->hdev = NULL;
199 		hci_free_dev(hdev);
200 		return;
201 	}
202 
203 	set_bit(HCI_UART_REGISTERED, &hu->flags);
204 }
205 
hci_uart_init_ready(struct hci_uart * hu)206 int hci_uart_init_ready(struct hci_uart *hu)
207 {
208 	if (!test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
209 		return -EALREADY;
210 
211 	schedule_work(&hu->init_ready);
212 
213 	return 0;
214 }
215 
hci_uart_wait_until_sent(struct hci_uart * hu)216 int hci_uart_wait_until_sent(struct hci_uart *hu)
217 {
218 	return wait_on_bit_timeout(&hu->tx_state, HCI_UART_SENDING,
219 				   TASK_INTERRUPTIBLE,
220 				   msecs_to_jiffies(2000));
221 }
222 
223 /* ------- Interface to HCI layer ------ */
224 /* Reset device */
hci_uart_flush(struct hci_dev * hdev)225 static int hci_uart_flush(struct hci_dev *hdev)
226 {
227 	struct hci_uart *hu  = hci_get_drvdata(hdev);
228 	struct tty_struct *tty = hu->tty;
229 
230 	BT_DBG("hdev %p tty %p", hdev, tty);
231 
232 	if (hu->tx_skb) {
233 		kfree_skb(hu->tx_skb); hu->tx_skb = NULL;
234 	}
235 
236 	/* Flush any pending characters in the driver and discipline. */
237 	tty_ldisc_flush(tty);
238 	tty_driver_flush_buffer(tty);
239 
240 	percpu_down_read(&hu->proto_lock);
241 
242 	if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
243 		hu->proto->flush(hu);
244 
245 	percpu_up_read(&hu->proto_lock);
246 
247 	return 0;
248 }
249 
250 /* Initialize device */
hci_uart_open(struct hci_dev * hdev)251 static int hci_uart_open(struct hci_dev *hdev)
252 {
253 	BT_DBG("%s %p", hdev->name, hdev);
254 
255 	/* Undo clearing this from hci_uart_close() */
256 	hdev->flush = hci_uart_flush;
257 
258 	return 0;
259 }
260 
261 /* Close device */
hci_uart_close(struct hci_dev * hdev)262 static int hci_uart_close(struct hci_dev *hdev)
263 {
264 	BT_DBG("hdev %p", hdev);
265 
266 	hci_uart_flush(hdev);
267 	hdev->flush = NULL;
268 	return 0;
269 }
270 
271 /* Send frames from HCI layer */
hci_uart_send_frame(struct hci_dev * hdev,struct sk_buff * skb)272 static int hci_uart_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
273 {
274 	struct hci_uart *hu = hci_get_drvdata(hdev);
275 
276 	BT_DBG("%s: type %d len %d", hdev->name, hci_skb_pkt_type(skb),
277 	       skb->len);
278 
279 	percpu_down_read(&hu->proto_lock);
280 
281 	if (!test_bit(HCI_UART_PROTO_READY, &hu->flags)) {
282 		percpu_up_read(&hu->proto_lock);
283 		return -EUNATCH;
284 	}
285 
286 	hu->proto->enqueue(hu, skb);
287 	percpu_up_read(&hu->proto_lock);
288 
289 	hci_uart_tx_wakeup(hu);
290 
291 	return 0;
292 }
293 
294 /* Check the underlying device or tty has flow control support */
hci_uart_has_flow_control(struct hci_uart * hu)295 bool hci_uart_has_flow_control(struct hci_uart *hu)
296 {
297 	/* serdev nodes check if the needed operations are present */
298 	if (hu->serdev)
299 		return true;
300 
301 	if (hu->tty->driver->ops->tiocmget && hu->tty->driver->ops->tiocmset)
302 		return true;
303 
304 	return false;
305 }
306 
307 /* Flow control or un-flow control the device */
hci_uart_set_flow_control(struct hci_uart * hu,bool enable)308 void hci_uart_set_flow_control(struct hci_uart *hu, bool enable)
309 {
310 	struct tty_struct *tty = hu->tty;
311 	struct ktermios ktermios;
312 	int status;
313 	unsigned int set = 0;
314 	unsigned int clear = 0;
315 
316 	if (hu->serdev) {
317 		serdev_device_set_flow_control(hu->serdev, !enable);
318 		serdev_device_set_rts(hu->serdev, !enable);
319 		return;
320 	}
321 
322 	if (enable) {
323 		/* Disable hardware flow control */
324 		ktermios = tty->termios;
325 		ktermios.c_cflag &= ~CRTSCTS;
326 		tty_set_termios(tty, &ktermios);
327 		BT_DBG("Disabling hardware flow control: %s",
328 		       (tty->termios.c_cflag & CRTSCTS) ? "failed" : "success");
329 
330 		/* Clear RTS to prevent the device from sending */
331 		/* Most UARTs need OUT2 to enable interrupts */
332 		status = tty->driver->ops->tiocmget(tty);
333 		BT_DBG("Current tiocm 0x%x", status);
334 
335 		set &= ~(TIOCM_OUT2 | TIOCM_RTS);
336 		clear = ~set;
337 		set &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
338 		       TIOCM_OUT2 | TIOCM_LOOP;
339 		clear &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
340 			 TIOCM_OUT2 | TIOCM_LOOP;
341 		status = tty->driver->ops->tiocmset(tty, set, clear);
342 		BT_DBG("Clearing RTS: %s", status ? "failed" : "success");
343 	} else {
344 		/* Set RTS to allow the device to send again */
345 		status = tty->driver->ops->tiocmget(tty);
346 		BT_DBG("Current tiocm 0x%x", status);
347 
348 		set |= (TIOCM_OUT2 | TIOCM_RTS);
349 		clear = ~set;
350 		set &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
351 		       TIOCM_OUT2 | TIOCM_LOOP;
352 		clear &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
353 			 TIOCM_OUT2 | TIOCM_LOOP;
354 		status = tty->driver->ops->tiocmset(tty, set, clear);
355 		BT_DBG("Setting RTS: %s", status ? "failed" : "success");
356 
357 		/* Re-enable hardware flow control */
358 		ktermios = tty->termios;
359 		ktermios.c_cflag |= CRTSCTS;
360 		tty_set_termios(tty, &ktermios);
361 		BT_DBG("Enabling hardware flow control: %s",
362 		       !(tty->termios.c_cflag & CRTSCTS) ? "failed" : "success");
363 	}
364 }
365 
hci_uart_set_speeds(struct hci_uart * hu,unsigned int init_speed,unsigned int oper_speed)366 void hci_uart_set_speeds(struct hci_uart *hu, unsigned int init_speed,
367 			 unsigned int oper_speed)
368 {
369 	hu->init_speed = init_speed;
370 	hu->oper_speed = oper_speed;
371 }
372 
hci_uart_set_baudrate(struct hci_uart * hu,unsigned int speed)373 void hci_uart_set_baudrate(struct hci_uart *hu, unsigned int speed)
374 {
375 	struct tty_struct *tty = hu->tty;
376 	struct ktermios ktermios;
377 
378 	ktermios = tty->termios;
379 	ktermios.c_cflag &= ~CBAUD;
380 	tty_termios_encode_baud_rate(&ktermios, speed, speed);
381 
382 	/* tty_set_termios() return not checked as it is always 0 */
383 	tty_set_termios(tty, &ktermios);
384 
385 	BT_DBG("%s: New tty speeds: %d/%d", hu->hdev->name,
386 	       tty->termios.c_ispeed, tty->termios.c_ospeed);
387 }
388 
hci_uart_setup(struct hci_dev * hdev)389 static int hci_uart_setup(struct hci_dev *hdev)
390 {
391 	struct hci_uart *hu = hci_get_drvdata(hdev);
392 	struct hci_rp_read_local_version *ver;
393 	struct sk_buff *skb;
394 	unsigned int speed;
395 	int err;
396 
397 	/* Init speed if any */
398 	if (hu->init_speed)
399 		speed = hu->init_speed;
400 	else if (hu->proto->init_speed)
401 		speed = hu->proto->init_speed;
402 	else
403 		speed = 0;
404 
405 	if (speed)
406 		hci_uart_set_baudrate(hu, speed);
407 
408 	/* Operational speed if any */
409 	if (hu->oper_speed)
410 		speed = hu->oper_speed;
411 	else if (hu->proto->oper_speed)
412 		speed = hu->proto->oper_speed;
413 	else
414 		speed = 0;
415 
416 	if (hu->proto->set_baudrate && speed) {
417 		err = hu->proto->set_baudrate(hu, speed);
418 		if (!err)
419 			hci_uart_set_baudrate(hu, speed);
420 	}
421 
422 	if (hu->proto->setup)
423 		return hu->proto->setup(hu);
424 
425 	if (!test_bit(HCI_UART_VND_DETECT, &hu->hdev_flags))
426 		return 0;
427 
428 	skb = __hci_cmd_sync(hdev, HCI_OP_READ_LOCAL_VERSION, 0, NULL,
429 			     HCI_INIT_TIMEOUT);
430 	if (IS_ERR(skb)) {
431 		BT_ERR("%s: Reading local version information failed (%ld)",
432 		       hdev->name, PTR_ERR(skb));
433 		return 0;
434 	}
435 
436 	if (skb->len != sizeof(*ver)) {
437 		BT_ERR("%s: Event length mismatch for version information",
438 		       hdev->name);
439 		goto done;
440 	}
441 
442 	ver = (struct hci_rp_read_local_version *)skb->data;
443 
444 	switch (le16_to_cpu(ver->manufacturer)) {
445 #ifdef CONFIG_BT_HCIUART_INTEL
446 	case 2:
447 		hdev->set_bdaddr = btintel_set_bdaddr;
448 		btintel_check_bdaddr(hdev);
449 		break;
450 #endif
451 #ifdef CONFIG_BT_HCIUART_BCM
452 	case 15:
453 		hdev->set_bdaddr = btbcm_set_bdaddr;
454 		btbcm_check_bdaddr(hdev);
455 		break;
456 #endif
457 	default:
458 		break;
459 	}
460 
461 done:
462 	kfree_skb(skb);
463 	return 0;
464 }
465 
466 /* ------ LDISC part ------ */
467 /* hci_uart_tty_open
468  *
469  *     Called when line discipline changed to HCI_UART.
470  *
471  * Arguments:
472  *     tty    pointer to tty info structure
473  * Return Value:
474  *     0 if success, otherwise error code
475  */
hci_uart_tty_open(struct tty_struct * tty)476 static int hci_uart_tty_open(struct tty_struct *tty)
477 {
478 	struct hci_uart *hu;
479 
480 	BT_DBG("tty %p", tty);
481 
482 	if (!capable(CAP_NET_ADMIN))
483 		return -EPERM;
484 
485 	/* Error if the tty has no write op instead of leaving an exploitable
486 	 * hole
487 	 */
488 	if (tty->ops->write == NULL)
489 		return -EOPNOTSUPP;
490 
491 	hu = kzalloc(sizeof(*hu), GFP_KERNEL);
492 	if (!hu) {
493 		BT_ERR("Can't allocate control structure");
494 		return -ENFILE;
495 	}
496 	if (percpu_init_rwsem(&hu->proto_lock)) {
497 		BT_ERR("Can't allocate semaphore structure");
498 		kfree(hu);
499 		return -ENOMEM;
500 	}
501 
502 	tty->disc_data = hu;
503 	hu->tty = tty;
504 	tty->receive_room = 65536;
505 
506 	/* disable alignment support by default */
507 	hu->alignment = 1;
508 	hu->padding = 0;
509 
510 	/* Use serial port speed as oper_speed */
511 	hu->oper_speed = tty->termios.c_ospeed;
512 
513 	INIT_WORK(&hu->init_ready, hci_uart_init_work);
514 	INIT_WORK(&hu->write_work, hci_uart_write_work);
515 
516 	/* Flush any pending characters in the driver */
517 	tty_driver_flush_buffer(tty);
518 
519 	return 0;
520 }
521 
522 /* hci_uart_tty_close()
523  *
524  *    Called when the line discipline is changed to something
525  *    else, the tty is closed, or the tty detects a hangup.
526  */
hci_uart_tty_close(struct tty_struct * tty)527 static void hci_uart_tty_close(struct tty_struct *tty)
528 {
529 	struct hci_uart *hu = tty->disc_data;
530 	struct hci_dev *hdev;
531 
532 	BT_DBG("tty %p", tty);
533 
534 	/* Detach from the tty */
535 	tty->disc_data = NULL;
536 
537 	if (!hu)
538 		return;
539 
540 	hdev = hu->hdev;
541 	if (hdev)
542 		hci_uart_close(hdev);
543 
544 	if (test_bit(HCI_UART_PROTO_READY, &hu->flags)) {
545 		percpu_down_write(&hu->proto_lock);
546 		clear_bit(HCI_UART_PROTO_READY, &hu->flags);
547 		percpu_up_write(&hu->proto_lock);
548 
549 		cancel_work_sync(&hu->init_ready);
550 		cancel_work_sync(&hu->write_work);
551 
552 		if (hdev) {
553 			if (test_bit(HCI_UART_REGISTERED, &hu->flags))
554 				hci_unregister_dev(hdev);
555 			hci_free_dev(hdev);
556 		}
557 		hu->proto->close(hu);
558 	}
559 	clear_bit(HCI_UART_PROTO_SET, &hu->flags);
560 
561 	percpu_free_rwsem(&hu->proto_lock);
562 
563 	kfree(hu);
564 }
565 
566 /* hci_uart_tty_wakeup()
567  *
568  *    Callback for transmit wakeup. Called when low level
569  *    device driver can accept more send data.
570  *
571  * Arguments:        tty    pointer to associated tty instance data
572  * Return Value:    None
573  */
hci_uart_tty_wakeup(struct tty_struct * tty)574 static void hci_uart_tty_wakeup(struct tty_struct *tty)
575 {
576 	struct hci_uart *hu = tty->disc_data;
577 
578 	BT_DBG("");
579 
580 	if (!hu)
581 		return;
582 
583 	clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
584 
585 	if (tty != hu->tty)
586 		return;
587 
588 	if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
589 		hci_uart_tx_wakeup(hu);
590 }
591 
592 /* hci_uart_tty_receive()
593  *
594  *     Called by tty low level driver when receive data is
595  *     available.
596  *
597  * Arguments:  tty          pointer to tty isntance data
598  *             data         pointer to received data
599  *             flags        pointer to flags for data
600  *             count        count of received data in bytes
601  *
602  * Return Value:    None
603  */
hci_uart_tty_receive(struct tty_struct * tty,const u8 * data,const u8 * flags,size_t count)604 static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data,
605 				 const u8 *flags, size_t count)
606 {
607 	struct hci_uart *hu = tty->disc_data;
608 
609 	if (!hu || tty != hu->tty)
610 		return;
611 
612 	percpu_down_read(&hu->proto_lock);
613 
614 	if (!test_bit(HCI_UART_PROTO_READY, &hu->flags)) {
615 		percpu_up_read(&hu->proto_lock);
616 		return;
617 	}
618 
619 	/* It does not need a lock here as it is already protected by a mutex in
620 	 * tty caller
621 	 */
622 	hu->proto->recv(hu, data, count);
623 	percpu_up_read(&hu->proto_lock);
624 
625 	if (hu->hdev)
626 		hu->hdev->stat.byte_rx += count;
627 
628 	tty_unthrottle(tty);
629 }
630 
hci_uart_register_dev(struct hci_uart * hu)631 static int hci_uart_register_dev(struct hci_uart *hu)
632 {
633 	struct hci_dev *hdev;
634 	int err;
635 
636 	BT_DBG("");
637 
638 	/* Initialize and register HCI device */
639 	hdev = hci_alloc_dev();
640 	if (!hdev) {
641 		BT_ERR("Can't allocate HCI device");
642 		return -ENOMEM;
643 	}
644 
645 	hu->hdev = hdev;
646 
647 	hdev->bus = HCI_UART;
648 	hci_set_drvdata(hdev, hu);
649 
650 	/* Only when vendor specific setup callback is provided, consider
651 	 * the manufacturer information valid. This avoids filling in the
652 	 * value for Ericsson when nothing is specified.
653 	 */
654 	if (hu->proto->setup)
655 		hdev->manufacturer = hu->proto->manufacturer;
656 
657 	hdev->open  = hci_uart_open;
658 	hdev->close = hci_uart_close;
659 	hdev->flush = hci_uart_flush;
660 	hdev->send  = hci_uart_send_frame;
661 	hdev->setup = hci_uart_setup;
662 	SET_HCIDEV_DEV(hdev, hu->tty->dev);
663 
664 	if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags))
665 		set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
666 
667 	if (test_bit(HCI_UART_EXT_CONFIG, &hu->hdev_flags))
668 		set_bit(HCI_QUIRK_EXTERNAL_CONFIG, &hdev->quirks);
669 
670 	if (!test_bit(HCI_UART_RESET_ON_INIT, &hu->hdev_flags))
671 		set_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks);
672 
673 	/* Only call open() for the protocol after hdev is fully initialized as
674 	 * open() (or a timer/workqueue it starts) may attempt to reference it.
675 	 */
676 	err = hu->proto->open(hu);
677 	if (err) {
678 		hu->hdev = NULL;
679 		hci_free_dev(hdev);
680 		return err;
681 	}
682 
683 	if (test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
684 		return 0;
685 
686 	if (hci_register_dev(hdev) < 0) {
687 		BT_ERR("Can't register HCI device");
688 		hu->proto->close(hu);
689 		hu->hdev = NULL;
690 		hci_free_dev(hdev);
691 		return -ENODEV;
692 	}
693 
694 	set_bit(HCI_UART_REGISTERED, &hu->flags);
695 
696 	return 0;
697 }
698 
hci_uart_set_proto(struct hci_uart * hu,int id)699 static int hci_uart_set_proto(struct hci_uart *hu, int id)
700 {
701 	const struct hci_uart_proto *p;
702 	int err;
703 
704 	p = hci_uart_get_proto(id);
705 	if (!p)
706 		return -EPROTONOSUPPORT;
707 
708 	hu->proto = p;
709 
710 	err = hci_uart_register_dev(hu);
711 	if (err) {
712 		return err;
713 	}
714 
715 	set_bit(HCI_UART_PROTO_READY, &hu->flags);
716 	return 0;
717 }
718 
hci_uart_set_flags(struct hci_uart * hu,unsigned long flags)719 static int hci_uart_set_flags(struct hci_uart *hu, unsigned long flags)
720 {
721 	unsigned long valid_flags = BIT(HCI_UART_RAW_DEVICE) |
722 				    BIT(HCI_UART_RESET_ON_INIT) |
723 				    BIT(HCI_UART_INIT_PENDING) |
724 				    BIT(HCI_UART_EXT_CONFIG) |
725 				    BIT(HCI_UART_VND_DETECT);
726 
727 	if (flags & ~valid_flags)
728 		return -EINVAL;
729 
730 	hu->hdev_flags = flags;
731 
732 	return 0;
733 }
734 
735 /* hci_uart_tty_ioctl()
736  *
737  *    Process IOCTL system call for the tty device.
738  *
739  * Arguments:
740  *
741  *    tty        pointer to tty instance data
742  *    cmd        IOCTL command code
743  *    arg        argument for IOCTL call (cmd dependent)
744  *
745  * Return Value:    Command dependent
746  */
hci_uart_tty_ioctl(struct tty_struct * tty,unsigned int cmd,unsigned long arg)747 static int hci_uart_tty_ioctl(struct tty_struct *tty, unsigned int cmd,
748 			      unsigned long arg)
749 {
750 	struct hci_uart *hu = tty->disc_data;
751 	int err = 0;
752 
753 	BT_DBG("");
754 
755 	/* Verify the status of the device */
756 	if (!hu)
757 		return -EBADF;
758 
759 	switch (cmd) {
760 	case HCIUARTSETPROTO:
761 		if (!test_and_set_bit(HCI_UART_PROTO_SET, &hu->flags)) {
762 			err = hci_uart_set_proto(hu, arg);
763 			if (err)
764 				clear_bit(HCI_UART_PROTO_SET, &hu->flags);
765 		} else
766 			err = -EBUSY;
767 		break;
768 
769 	case HCIUARTGETPROTO:
770 		if (test_bit(HCI_UART_PROTO_SET, &hu->flags) &&
771 		    test_bit(HCI_UART_PROTO_READY, &hu->flags))
772 			err = hu->proto->id;
773 		else
774 			err = -EUNATCH;
775 		break;
776 
777 	case HCIUARTGETDEVICE:
778 		if (test_bit(HCI_UART_REGISTERED, &hu->flags))
779 			err = hu->hdev->id;
780 		else
781 			err = -EUNATCH;
782 		break;
783 
784 	case HCIUARTSETFLAGS:
785 		if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
786 			err = -EBUSY;
787 		else
788 			err = hci_uart_set_flags(hu, arg);
789 		break;
790 
791 	case HCIUARTGETFLAGS:
792 		err = hu->hdev_flags;
793 		break;
794 
795 	default:
796 		err = n_tty_ioctl_helper(tty, cmd, arg);
797 		break;
798 	}
799 
800 	return err;
801 }
802 
803 /*
804  * We don't provide read/write/poll interface for user space.
805  */
hci_uart_tty_read(struct tty_struct * tty,struct file * file,u8 * buf,size_t nr,void ** cookie,unsigned long offset)806 static ssize_t hci_uart_tty_read(struct tty_struct *tty, struct file *file,
807 				 u8 *buf, size_t nr, void **cookie,
808 				 unsigned long offset)
809 {
810 	return 0;
811 }
812 
hci_uart_tty_write(struct tty_struct * tty,struct file * file,const u8 * data,size_t count)813 static ssize_t hci_uart_tty_write(struct tty_struct *tty, struct file *file,
814 				  const u8 *data, size_t count)
815 {
816 	return 0;
817 }
818 
819 static struct tty_ldisc_ops hci_uart_ldisc = {
820 	.owner		= THIS_MODULE,
821 	.num		= N_HCI,
822 	.name		= "n_hci",
823 	.open		= hci_uart_tty_open,
824 	.close		= hci_uart_tty_close,
825 	.read		= hci_uart_tty_read,
826 	.write		= hci_uart_tty_write,
827 	.ioctl		= hci_uart_tty_ioctl,
828 	.compat_ioctl	= hci_uart_tty_ioctl,
829 	.receive_buf	= hci_uart_tty_receive,
830 	.write_wakeup	= hci_uart_tty_wakeup,
831 };
832 
hci_uart_init(void)833 static int __init hci_uart_init(void)
834 {
835 	int err;
836 
837 	BT_INFO("HCI UART driver ver %s", VERSION);
838 
839 	/* Register the tty discipline */
840 	err = tty_register_ldisc(&hci_uart_ldisc);
841 	if (err) {
842 		BT_ERR("HCI line discipline registration failed. (%d)", err);
843 		return err;
844 	}
845 
846 #ifdef CONFIG_BT_HCIUART_H4
847 	h4_init();
848 #endif
849 #ifdef CONFIG_BT_HCIUART_BCSP
850 	bcsp_init();
851 #endif
852 #ifdef CONFIG_BT_HCIUART_LL
853 	ll_init();
854 #endif
855 #ifdef CONFIG_BT_HCIUART_ATH3K
856 	ath_init();
857 #endif
858 #ifdef CONFIG_BT_HCIUART_3WIRE
859 	h5_init();
860 #endif
861 #ifdef CONFIG_BT_HCIUART_INTEL
862 	intel_init();
863 #endif
864 #ifdef CONFIG_BT_HCIUART_BCM
865 	bcm_init();
866 #endif
867 #ifdef CONFIG_BT_HCIUART_QCA
868 	qca_init();
869 #endif
870 #ifdef CONFIG_BT_HCIUART_AG6XX
871 	ag6xx_init();
872 #endif
873 #ifdef CONFIG_BT_HCIUART_MRVL
874 	mrvl_init();
875 #endif
876 #ifdef CONFIG_BT_HCIUART_AML
877 	aml_init();
878 #endif
879 	return 0;
880 }
881 
hci_uart_exit(void)882 static void __exit hci_uart_exit(void)
883 {
884 #ifdef CONFIG_BT_HCIUART_H4
885 	h4_deinit();
886 #endif
887 #ifdef CONFIG_BT_HCIUART_BCSP
888 	bcsp_deinit();
889 #endif
890 #ifdef CONFIG_BT_HCIUART_LL
891 	ll_deinit();
892 #endif
893 #ifdef CONFIG_BT_HCIUART_ATH3K
894 	ath_deinit();
895 #endif
896 #ifdef CONFIG_BT_HCIUART_3WIRE
897 	h5_deinit();
898 #endif
899 #ifdef CONFIG_BT_HCIUART_INTEL
900 	intel_deinit();
901 #endif
902 #ifdef CONFIG_BT_HCIUART_BCM
903 	bcm_deinit();
904 #endif
905 #ifdef CONFIG_BT_HCIUART_QCA
906 	qca_deinit();
907 #endif
908 #ifdef CONFIG_BT_HCIUART_AG6XX
909 	ag6xx_deinit();
910 #endif
911 #ifdef CONFIG_BT_HCIUART_MRVL
912 	mrvl_deinit();
913 #endif
914 #ifdef CONFIG_BT_HCIUART_AML
915 	aml_deinit();
916 #endif
917 	tty_unregister_ldisc(&hci_uart_ldisc);
918 }
919 
920 module_init(hci_uart_init);
921 module_exit(hci_uart_exit);
922 
923 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
924 MODULE_DESCRIPTION("Bluetooth HCI UART driver ver " VERSION);
925 MODULE_VERSION(VERSION);
926 MODULE_LICENSE("GPL");
927 MODULE_ALIAS_LDISC(N_HCI);
928