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 <[email protected]>
8  *  Copyright (C) 2004-2005  Marcel Holtmann <[email protected]>
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 		    test_bit(HCI_UART_PROTO_INIT, &hu->flags))
107 			skb = hu->proto->dequeue(hu);
108 
109 		percpu_up_read(&hu->proto_lock);
110 	} else {
111 		hu->tx_skb = NULL;
112 	}
113 
114 	return skb;
115 }
116 
hci_uart_tx_wakeup(struct hci_uart * hu)117 int hci_uart_tx_wakeup(struct hci_uart *hu)
118 {
119 	/* This may be called in an IRQ context, so we can't sleep. Therefore
120 	 * we try to acquire the lock only, and if that fails we assume the
121 	 * tty is being closed because that is the only time the write lock is
122 	 * acquired. If, however, at some point in the future the write lock
123 	 * is also acquired in other situations, then this must be revisited.
124 	 */
125 	if (!percpu_down_read_trylock(&hu->proto_lock))
126 		return 0;
127 
128 	if (!test_bit(HCI_UART_PROTO_READY, &hu->flags) &&
129 	    !test_bit(HCI_UART_PROTO_INIT, &hu->flags))
130 		goto no_schedule;
131 
132 	set_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
133 	if (test_and_set_bit(HCI_UART_SENDING, &hu->tx_state))
134 		goto no_schedule;
135 
136 	BT_DBG("");
137 
138 	schedule_work(&hu->write_work);
139 
140 no_schedule:
141 	percpu_up_read(&hu->proto_lock);
142 
143 	return 0;
144 }
145 EXPORT_SYMBOL_GPL(hci_uart_tx_wakeup);
146 
hci_uart_write_work(struct work_struct * work)147 static void hci_uart_write_work(struct work_struct *work)
148 {
149 	struct hci_uart *hu = container_of(work, struct hci_uart, write_work);
150 	struct tty_struct *tty = hu->tty;
151 	struct hci_dev *hdev = hu->hdev;
152 	struct sk_buff *skb;
153 
154 	/* REVISIT: should we cope with bad skbs or ->write() returning
155 	 * and error value ?
156 	 */
157 
158 restart:
159 	clear_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
160 
161 	while ((skb = hci_uart_dequeue(hu))) {
162 		int len;
163 
164 		set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
165 		len = tty->ops->write(tty, skb->data, skb->len);
166 		hdev->stat.byte_tx += len;
167 
168 		skb_pull(skb, len);
169 		if (skb->len) {
170 			hu->tx_skb = skb;
171 			break;
172 		}
173 
174 		hci_uart_tx_complete(hu, hci_skb_pkt_type(skb));
175 		kfree_skb(skb);
176 	}
177 
178 	clear_bit(HCI_UART_SENDING, &hu->tx_state);
179 	if (test_bit(HCI_UART_TX_WAKEUP, &hu->tx_state))
180 		goto restart;
181 
182 	wake_up_bit(&hu->tx_state, HCI_UART_SENDING);
183 }
184 
hci_uart_init_work(struct work_struct * work)185 void hci_uart_init_work(struct work_struct *work)
186 {
187 	struct hci_uart *hu = container_of(work, struct hci_uart, init_ready);
188 	int err;
189 	struct hci_dev *hdev;
190 
191 	if (!test_and_clear_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
192 		return;
193 
194 	err = hci_register_dev(hu->hdev);
195 	if (err < 0) {
196 		BT_ERR("Can't register HCI device");
197 		clear_bit(HCI_UART_PROTO_READY, &hu->flags);
198 		hu->proto->close(hu);
199 		hdev = hu->hdev;
200 		hu->hdev = NULL;
201 		hci_free_dev(hdev);
202 		return;
203 	}
204 
205 	set_bit(HCI_UART_REGISTERED, &hu->flags);
206 }
207 
hci_uart_init_ready(struct hci_uart * hu)208 int hci_uart_init_ready(struct hci_uart *hu)
209 {
210 	if (!test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
211 		return -EALREADY;
212 
213 	schedule_work(&hu->init_ready);
214 
215 	return 0;
216 }
217 
hci_uart_wait_until_sent(struct hci_uart * hu)218 int hci_uart_wait_until_sent(struct hci_uart *hu)
219 {
220 	return wait_on_bit_timeout(&hu->tx_state, HCI_UART_SENDING,
221 				   TASK_INTERRUPTIBLE,
222 				   msecs_to_jiffies(2000));
223 }
224 
225 /* ------- Interface to HCI layer ------ */
226 /* Reset device */
hci_uart_flush(struct hci_dev * hdev)227 static int hci_uart_flush(struct hci_dev *hdev)
228 {
229 	struct hci_uart *hu  = hci_get_drvdata(hdev);
230 	struct tty_struct *tty = hu->tty;
231 
232 	BT_DBG("hdev %p tty %p", hdev, tty);
233 
234 	if (hu->tx_skb) {
235 		kfree_skb(hu->tx_skb); hu->tx_skb = NULL;
236 	}
237 
238 	/* Flush any pending characters in the driver and discipline. */
239 	tty_ldisc_flush(tty);
240 	tty_driver_flush_buffer(tty);
241 
242 	percpu_down_read(&hu->proto_lock);
243 
244 	if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
245 		hu->proto->flush(hu);
246 
247 	percpu_up_read(&hu->proto_lock);
248 
249 	return 0;
250 }
251 
252 /* Initialize device */
hci_uart_open(struct hci_dev * hdev)253 static int hci_uart_open(struct hci_dev *hdev)
254 {
255 	BT_DBG("%s %p", hdev->name, hdev);
256 
257 	/* Undo clearing this from hci_uart_close() */
258 	hdev->flush = hci_uart_flush;
259 
260 	return 0;
261 }
262 
263 /* Close device */
hci_uart_close(struct hci_dev * hdev)264 static int hci_uart_close(struct hci_dev *hdev)
265 {
266 	BT_DBG("hdev %p", hdev);
267 
268 	hci_uart_flush(hdev);
269 	hdev->flush = NULL;
270 	return 0;
271 }
272 
273 /* Send frames from HCI layer */
hci_uart_send_frame(struct hci_dev * hdev,struct sk_buff * skb)274 static int hci_uart_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
275 {
276 	struct hci_uart *hu = hci_get_drvdata(hdev);
277 
278 	BT_DBG("%s: type %d len %d", hdev->name, hci_skb_pkt_type(skb),
279 	       skb->len);
280 
281 	percpu_down_read(&hu->proto_lock);
282 
283 	if (!test_bit(HCI_UART_PROTO_READY, &hu->flags) &&
284 	    !test_bit(HCI_UART_PROTO_INIT, &hu->flags)) {
285 		percpu_up_read(&hu->proto_lock);
286 		return -EUNATCH;
287 	}
288 
289 	hu->proto->enqueue(hu, skb);
290 	percpu_up_read(&hu->proto_lock);
291 
292 	hci_uart_tx_wakeup(hu);
293 
294 	return 0;
295 }
296 
297 /* Check the underlying device or tty has flow control support */
hci_uart_has_flow_control(struct hci_uart * hu)298 bool hci_uart_has_flow_control(struct hci_uart *hu)
299 {
300 	/* serdev nodes check if the needed operations are present */
301 	if (hu->serdev)
302 		return true;
303 
304 	if (hu->tty->driver->ops->tiocmget && hu->tty->driver->ops->tiocmset)
305 		return true;
306 
307 	return false;
308 }
309 
310 /* Flow control or un-flow control the device */
hci_uart_set_flow_control(struct hci_uart * hu,bool enable)311 void hci_uart_set_flow_control(struct hci_uart *hu, bool enable)
312 {
313 	struct tty_struct *tty = hu->tty;
314 	struct ktermios ktermios;
315 	int status;
316 	unsigned int set = 0;
317 	unsigned int clear = 0;
318 
319 	if (hu->serdev) {
320 		serdev_device_set_flow_control(hu->serdev, !enable);
321 		serdev_device_set_rts(hu->serdev, !enable);
322 		return;
323 	}
324 
325 	if (enable) {
326 		/* Disable hardware flow control */
327 		ktermios = tty->termios;
328 		ktermios.c_cflag &= ~CRTSCTS;
329 		tty_set_termios(tty, &ktermios);
330 		BT_DBG("Disabling hardware flow control: %s",
331 		       (tty->termios.c_cflag & CRTSCTS) ? "failed" : "success");
332 
333 		/* Clear RTS to prevent the device from sending */
334 		/* Most UARTs need OUT2 to enable interrupts */
335 		status = tty->driver->ops->tiocmget(tty);
336 		BT_DBG("Current tiocm 0x%x", status);
337 
338 		set &= ~(TIOCM_OUT2 | TIOCM_RTS);
339 		clear = ~set;
340 		set &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
341 		       TIOCM_OUT2 | TIOCM_LOOP;
342 		clear &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
343 			 TIOCM_OUT2 | TIOCM_LOOP;
344 		status = tty->driver->ops->tiocmset(tty, set, clear);
345 		BT_DBG("Clearing RTS: %s", status ? "failed" : "success");
346 	} else {
347 		/* Set RTS to allow the device to send again */
348 		status = tty->driver->ops->tiocmget(tty);
349 		BT_DBG("Current tiocm 0x%x", status);
350 
351 		set |= (TIOCM_OUT2 | TIOCM_RTS);
352 		clear = ~set;
353 		set &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
354 		       TIOCM_OUT2 | TIOCM_LOOP;
355 		clear &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
356 			 TIOCM_OUT2 | TIOCM_LOOP;
357 		status = tty->driver->ops->tiocmset(tty, set, clear);
358 		BT_DBG("Setting RTS: %s", status ? "failed" : "success");
359 
360 		/* Re-enable hardware flow control */
361 		ktermios = tty->termios;
362 		ktermios.c_cflag |= CRTSCTS;
363 		tty_set_termios(tty, &ktermios);
364 		BT_DBG("Enabling hardware flow control: %s",
365 		       !(tty->termios.c_cflag & CRTSCTS) ? "failed" : "success");
366 	}
367 }
368 
hci_uart_set_speeds(struct hci_uart * hu,unsigned int init_speed,unsigned int oper_speed)369 void hci_uart_set_speeds(struct hci_uart *hu, unsigned int init_speed,
370 			 unsigned int oper_speed)
371 {
372 	hu->init_speed = init_speed;
373 	hu->oper_speed = oper_speed;
374 }
375 
hci_uart_set_baudrate(struct hci_uart * hu,unsigned int speed)376 void hci_uart_set_baudrate(struct hci_uart *hu, unsigned int speed)
377 {
378 	struct tty_struct *tty = hu->tty;
379 	struct ktermios ktermios;
380 
381 	ktermios = tty->termios;
382 	ktermios.c_cflag &= ~CBAUD;
383 	tty_termios_encode_baud_rate(&ktermios, speed, speed);
384 
385 	/* tty_set_termios() return not checked as it is always 0 */
386 	tty_set_termios(tty, &ktermios);
387 
388 	BT_DBG("%s: New tty speeds: %d/%d", hu->hdev->name,
389 	       tty->termios.c_ispeed, tty->termios.c_ospeed);
390 }
391 
hci_uart_setup(struct hci_dev * hdev)392 static int hci_uart_setup(struct hci_dev *hdev)
393 {
394 	struct hci_uart *hu = hci_get_drvdata(hdev);
395 	struct hci_rp_read_local_version *ver;
396 	struct sk_buff *skb;
397 	unsigned int speed;
398 	int err;
399 
400 	/* Init speed if any */
401 	if (hu->init_speed)
402 		speed = hu->init_speed;
403 	else if (hu->proto->init_speed)
404 		speed = hu->proto->init_speed;
405 	else
406 		speed = 0;
407 
408 	if (speed)
409 		hci_uart_set_baudrate(hu, speed);
410 
411 	/* Operational speed if any */
412 	if (hu->oper_speed)
413 		speed = hu->oper_speed;
414 	else if (hu->proto->oper_speed)
415 		speed = hu->proto->oper_speed;
416 	else
417 		speed = 0;
418 
419 	if (hu->proto->set_baudrate && speed) {
420 		err = hu->proto->set_baudrate(hu, speed);
421 		if (!err)
422 			hci_uart_set_baudrate(hu, speed);
423 	}
424 
425 	if (hu->proto->setup)
426 		return hu->proto->setup(hu);
427 
428 	if (!test_bit(HCI_UART_VND_DETECT, &hu->hdev_flags))
429 		return 0;
430 
431 	skb = __hci_cmd_sync(hdev, HCI_OP_READ_LOCAL_VERSION, 0, NULL,
432 			     HCI_INIT_TIMEOUT);
433 	if (IS_ERR(skb)) {
434 		BT_ERR("%s: Reading local version information failed (%ld)",
435 		       hdev->name, PTR_ERR(skb));
436 		return 0;
437 	}
438 
439 	if (skb->len != sizeof(*ver)) {
440 		BT_ERR("%s: Event length mismatch for version information",
441 		       hdev->name);
442 		goto done;
443 	}
444 
445 	ver = (struct hci_rp_read_local_version *)skb->data;
446 
447 	switch (le16_to_cpu(ver->manufacturer)) {
448 #ifdef CONFIG_BT_HCIUART_INTEL
449 	case 2:
450 		hdev->set_bdaddr = btintel_set_bdaddr;
451 		btintel_check_bdaddr(hdev);
452 		break;
453 #endif
454 #ifdef CONFIG_BT_HCIUART_BCM
455 	case 15:
456 		hdev->set_bdaddr = btbcm_set_bdaddr;
457 		btbcm_check_bdaddr(hdev);
458 		break;
459 #endif
460 	default:
461 		break;
462 	}
463 
464 done:
465 	kfree_skb(skb);
466 	return 0;
467 }
468 
469 /* ------ LDISC part ------ */
470 /* hci_uart_tty_open
471  *
472  *     Called when line discipline changed to HCI_UART.
473  *
474  * Arguments:
475  *     tty    pointer to tty info structure
476  * Return Value:
477  *     0 if success, otherwise error code
478  */
hci_uart_tty_open(struct tty_struct * tty)479 static int hci_uart_tty_open(struct tty_struct *tty)
480 {
481 	struct hci_uart *hu;
482 
483 	BT_DBG("tty %p", tty);
484 
485 	if (!capable(CAP_NET_ADMIN))
486 		return -EPERM;
487 
488 	/* Error if the tty has no write op instead of leaving an exploitable
489 	 * hole
490 	 */
491 	if (tty->ops->write == NULL)
492 		return -EOPNOTSUPP;
493 
494 	hu = kzalloc(sizeof(*hu), GFP_KERNEL);
495 	if (!hu) {
496 		BT_ERR("Can't allocate control structure");
497 		return -ENFILE;
498 	}
499 	if (percpu_init_rwsem(&hu->proto_lock)) {
500 		BT_ERR("Can't allocate semaphore structure");
501 		kfree(hu);
502 		return -ENOMEM;
503 	}
504 
505 	tty->disc_data = hu;
506 	hu->tty = tty;
507 	tty->receive_room = 65536;
508 
509 	/* disable alignment support by default */
510 	hu->alignment = 1;
511 	hu->padding = 0;
512 
513 	/* Use serial port speed as oper_speed */
514 	hu->oper_speed = tty->termios.c_ospeed;
515 
516 	INIT_WORK(&hu->init_ready, hci_uart_init_work);
517 	INIT_WORK(&hu->write_work, hci_uart_write_work);
518 
519 	/* Flush any pending characters in the driver */
520 	tty_driver_flush_buffer(tty);
521 
522 	return 0;
523 }
524 
525 /* hci_uart_tty_close()
526  *
527  *    Called when the line discipline is changed to something
528  *    else, the tty is closed, or the tty detects a hangup.
529  */
hci_uart_tty_close(struct tty_struct * tty)530 static void hci_uart_tty_close(struct tty_struct *tty)
531 {
532 	struct hci_uart *hu = tty->disc_data;
533 	struct hci_dev *hdev;
534 
535 	BT_DBG("tty %p", tty);
536 
537 	/* Detach from the tty */
538 	tty->disc_data = NULL;
539 
540 	if (!hu)
541 		return;
542 
543 	hdev = hu->hdev;
544 	if (hdev)
545 		hci_uart_close(hdev);
546 
547 	if (test_bit(HCI_UART_PROTO_READY, &hu->flags)) {
548 		percpu_down_write(&hu->proto_lock);
549 		clear_bit(HCI_UART_PROTO_READY, &hu->flags);
550 		percpu_up_write(&hu->proto_lock);
551 
552 		cancel_work_sync(&hu->init_ready);
553 		cancel_work_sync(&hu->write_work);
554 
555 		if (hdev) {
556 			if (test_bit(HCI_UART_REGISTERED, &hu->flags))
557 				hci_unregister_dev(hdev);
558 			hci_free_dev(hdev);
559 		}
560 		hu->proto->close(hu);
561 	}
562 	clear_bit(HCI_UART_PROTO_SET, &hu->flags);
563 
564 	percpu_free_rwsem(&hu->proto_lock);
565 
566 	kfree(hu);
567 }
568 
569 /* hci_uart_tty_wakeup()
570  *
571  *    Callback for transmit wakeup. Called when low level
572  *    device driver can accept more send data.
573  *
574  * Arguments:        tty    pointer to associated tty instance data
575  * Return Value:    None
576  */
hci_uart_tty_wakeup(struct tty_struct * tty)577 static void hci_uart_tty_wakeup(struct tty_struct *tty)
578 {
579 	struct hci_uart *hu = tty->disc_data;
580 
581 	BT_DBG("");
582 
583 	if (!hu)
584 		return;
585 
586 	clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
587 
588 	if (tty != hu->tty)
589 		return;
590 
591 	if (test_bit(HCI_UART_PROTO_READY, &hu->flags) ||
592 	    test_bit(HCI_UART_PROTO_INIT, &hu->flags))
593 		hci_uart_tx_wakeup(hu);
594 }
595 
596 /* hci_uart_tty_receive()
597  *
598  *     Called by tty low level driver when receive data is
599  *     available.
600  *
601  * Arguments:  tty          pointer to tty instance data
602  *             data         pointer to received data
603  *             flags        pointer to flags for data
604  *             count        count of received data in bytes
605  *
606  * Return Value:    None
607  */
hci_uart_tty_receive(struct tty_struct * tty,const u8 * data,const u8 * flags,size_t count)608 static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data,
609 				 const u8 *flags, size_t count)
610 {
611 	struct hci_uart *hu = tty->disc_data;
612 
613 	if (!hu || tty != hu->tty)
614 		return;
615 
616 	percpu_down_read(&hu->proto_lock);
617 
618 	if (!test_bit(HCI_UART_PROTO_READY, &hu->flags) &&
619 	    !test_bit(HCI_UART_PROTO_INIT, &hu->flags)) {
620 		percpu_up_read(&hu->proto_lock);
621 		return;
622 	}
623 
624 	/* It does not need a lock here as it is already protected by a mutex in
625 	 * tty caller
626 	 */
627 	hu->proto->recv(hu, data, count);
628 	percpu_up_read(&hu->proto_lock);
629 
630 	if (hu->hdev)
631 		hu->hdev->stat.byte_rx += count;
632 
633 	tty_unthrottle(tty);
634 }
635 
hci_uart_register_dev(struct hci_uart * hu)636 static int hci_uart_register_dev(struct hci_uart *hu)
637 {
638 	struct hci_dev *hdev;
639 	int err;
640 
641 	BT_DBG("");
642 
643 	/* Initialize and register HCI device */
644 	hdev = hci_alloc_dev();
645 	if (!hdev) {
646 		BT_ERR("Can't allocate HCI device");
647 		return -ENOMEM;
648 	}
649 
650 	hu->hdev = hdev;
651 
652 	hdev->bus = HCI_UART;
653 	hci_set_drvdata(hdev, hu);
654 
655 	/* Only when vendor specific setup callback is provided, consider
656 	 * the manufacturer information valid. This avoids filling in the
657 	 * value for Ericsson when nothing is specified.
658 	 */
659 	if (hu->proto->setup)
660 		hdev->manufacturer = hu->proto->manufacturer;
661 
662 	hdev->open  = hci_uart_open;
663 	hdev->close = hci_uart_close;
664 	hdev->flush = hci_uart_flush;
665 	hdev->send  = hci_uart_send_frame;
666 	hdev->setup = hci_uart_setup;
667 	SET_HCIDEV_DEV(hdev, hu->tty->dev);
668 
669 	if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags))
670 		set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
671 
672 	if (test_bit(HCI_UART_EXT_CONFIG, &hu->hdev_flags))
673 		set_bit(HCI_QUIRK_EXTERNAL_CONFIG, &hdev->quirks);
674 
675 	if (!test_bit(HCI_UART_RESET_ON_INIT, &hu->hdev_flags))
676 		set_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks);
677 
678 	/* Only call open() for the protocol after hdev is fully initialized as
679 	 * open() (or a timer/workqueue it starts) may attempt to reference it.
680 	 */
681 	err = hu->proto->open(hu);
682 	if (err) {
683 		hu->hdev = NULL;
684 		hci_free_dev(hdev);
685 		return err;
686 	}
687 
688 	if (test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
689 		return 0;
690 
691 	if (hci_register_dev(hdev) < 0) {
692 		BT_ERR("Can't register HCI device");
693 		hu->proto->close(hu);
694 		hu->hdev = NULL;
695 		hci_free_dev(hdev);
696 		return -ENODEV;
697 	}
698 
699 	set_bit(HCI_UART_REGISTERED, &hu->flags);
700 
701 	return 0;
702 }
703 
hci_uart_set_proto(struct hci_uart * hu,int id)704 static int hci_uart_set_proto(struct hci_uart *hu, int id)
705 {
706 	const struct hci_uart_proto *p;
707 	int err;
708 
709 	p = hci_uart_get_proto(id);
710 	if (!p)
711 		return -EPROTONOSUPPORT;
712 
713 	hu->proto = p;
714 
715 	set_bit(HCI_UART_PROTO_INIT, &hu->flags);
716 
717 	err = hci_uart_register_dev(hu);
718 	if (err) {
719 		return err;
720 	}
721 
722 	set_bit(HCI_UART_PROTO_READY, &hu->flags);
723 	clear_bit(HCI_UART_PROTO_INIT, &hu->flags);
724 
725 	return 0;
726 }
727 
hci_uart_set_flags(struct hci_uart * hu,unsigned long flags)728 static int hci_uart_set_flags(struct hci_uart *hu, unsigned long flags)
729 {
730 	unsigned long valid_flags = BIT(HCI_UART_RAW_DEVICE) |
731 				    BIT(HCI_UART_RESET_ON_INIT) |
732 				    BIT(HCI_UART_INIT_PENDING) |
733 				    BIT(HCI_UART_EXT_CONFIG) |
734 				    BIT(HCI_UART_VND_DETECT);
735 
736 	if (flags & ~valid_flags)
737 		return -EINVAL;
738 
739 	hu->hdev_flags = flags;
740 
741 	return 0;
742 }
743 
744 /* hci_uart_tty_ioctl()
745  *
746  *    Process IOCTL system call for the tty device.
747  *
748  * Arguments:
749  *
750  *    tty        pointer to tty instance data
751  *    cmd        IOCTL command code
752  *    arg        argument for IOCTL call (cmd dependent)
753  *
754  * Return Value:    Command dependent
755  */
hci_uart_tty_ioctl(struct tty_struct * tty,unsigned int cmd,unsigned long arg)756 static int hci_uart_tty_ioctl(struct tty_struct *tty, unsigned int cmd,
757 			      unsigned long arg)
758 {
759 	struct hci_uart *hu = tty->disc_data;
760 	int err = 0;
761 
762 	BT_DBG("");
763 
764 	/* Verify the status of the device */
765 	if (!hu)
766 		return -EBADF;
767 
768 	switch (cmd) {
769 	case HCIUARTSETPROTO:
770 		if (!test_and_set_bit(HCI_UART_PROTO_SET, &hu->flags)) {
771 			err = hci_uart_set_proto(hu, arg);
772 			if (err)
773 				clear_bit(HCI_UART_PROTO_SET, &hu->flags);
774 		} else
775 			err = -EBUSY;
776 		break;
777 
778 	case HCIUARTGETPROTO:
779 		if (test_bit(HCI_UART_PROTO_SET, &hu->flags) &&
780 		    test_bit(HCI_UART_PROTO_READY, &hu->flags))
781 			err = hu->proto->id;
782 		else
783 			err = -EUNATCH;
784 		break;
785 
786 	case HCIUARTGETDEVICE:
787 		if (test_bit(HCI_UART_REGISTERED, &hu->flags))
788 			err = hu->hdev->id;
789 		else
790 			err = -EUNATCH;
791 		break;
792 
793 	case HCIUARTSETFLAGS:
794 		if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
795 			err = -EBUSY;
796 		else
797 			err = hci_uart_set_flags(hu, arg);
798 		break;
799 
800 	case HCIUARTGETFLAGS:
801 		err = hu->hdev_flags;
802 		break;
803 
804 	default:
805 		err = n_tty_ioctl_helper(tty, cmd, arg);
806 		break;
807 	}
808 
809 	return err;
810 }
811 
812 /*
813  * We don't provide read/write/poll interface for user space.
814  */
hci_uart_tty_read(struct tty_struct * tty,struct file * file,u8 * buf,size_t nr,void ** cookie,unsigned long offset)815 static ssize_t hci_uart_tty_read(struct tty_struct *tty, struct file *file,
816 				 u8 *buf, size_t nr, void **cookie,
817 				 unsigned long offset)
818 {
819 	return 0;
820 }
821 
hci_uart_tty_write(struct tty_struct * tty,struct file * file,const u8 * data,size_t count)822 static ssize_t hci_uart_tty_write(struct tty_struct *tty, struct file *file,
823 				  const u8 *data, size_t count)
824 {
825 	return 0;
826 }
827 
828 static struct tty_ldisc_ops hci_uart_ldisc = {
829 	.owner		= THIS_MODULE,
830 	.num		= N_HCI,
831 	.name		= "n_hci",
832 	.open		= hci_uart_tty_open,
833 	.close		= hci_uart_tty_close,
834 	.read		= hci_uart_tty_read,
835 	.write		= hci_uart_tty_write,
836 	.ioctl		= hci_uart_tty_ioctl,
837 	.compat_ioctl	= hci_uart_tty_ioctl,
838 	.receive_buf	= hci_uart_tty_receive,
839 	.write_wakeup	= hci_uart_tty_wakeup,
840 };
841 
hci_uart_init(void)842 static int __init hci_uart_init(void)
843 {
844 	int err;
845 
846 	BT_INFO("HCI UART driver ver %s", VERSION);
847 
848 	/* Register the tty discipline */
849 	err = tty_register_ldisc(&hci_uart_ldisc);
850 	if (err) {
851 		BT_ERR("HCI line discipline registration failed. (%d)", err);
852 		return err;
853 	}
854 
855 #ifdef CONFIG_BT_HCIUART_H4
856 	h4_init();
857 #endif
858 #ifdef CONFIG_BT_HCIUART_BCSP
859 	bcsp_init();
860 #endif
861 #ifdef CONFIG_BT_HCIUART_LL
862 	ll_init();
863 #endif
864 #ifdef CONFIG_BT_HCIUART_ATH3K
865 	ath_init();
866 #endif
867 #ifdef CONFIG_BT_HCIUART_3WIRE
868 	h5_init();
869 #endif
870 #ifdef CONFIG_BT_HCIUART_INTEL
871 	intel_init();
872 #endif
873 #ifdef CONFIG_BT_HCIUART_BCM
874 	bcm_init();
875 #endif
876 #ifdef CONFIG_BT_HCIUART_QCA
877 	qca_init();
878 #endif
879 #ifdef CONFIG_BT_HCIUART_AG6XX
880 	ag6xx_init();
881 #endif
882 #ifdef CONFIG_BT_HCIUART_MRVL
883 	mrvl_init();
884 #endif
885 #ifdef CONFIG_BT_HCIUART_AML
886 	aml_init();
887 #endif
888 	return 0;
889 }
890 
hci_uart_exit(void)891 static void __exit hci_uart_exit(void)
892 {
893 #ifdef CONFIG_BT_HCIUART_H4
894 	h4_deinit();
895 #endif
896 #ifdef CONFIG_BT_HCIUART_BCSP
897 	bcsp_deinit();
898 #endif
899 #ifdef CONFIG_BT_HCIUART_LL
900 	ll_deinit();
901 #endif
902 #ifdef CONFIG_BT_HCIUART_ATH3K
903 	ath_deinit();
904 #endif
905 #ifdef CONFIG_BT_HCIUART_3WIRE
906 	h5_deinit();
907 #endif
908 #ifdef CONFIG_BT_HCIUART_INTEL
909 	intel_deinit();
910 #endif
911 #ifdef CONFIG_BT_HCIUART_BCM
912 	bcm_deinit();
913 #endif
914 #ifdef CONFIG_BT_HCIUART_QCA
915 	qca_deinit();
916 #endif
917 #ifdef CONFIG_BT_HCIUART_AG6XX
918 	ag6xx_deinit();
919 #endif
920 #ifdef CONFIG_BT_HCIUART_MRVL
921 	mrvl_deinit();
922 #endif
923 #ifdef CONFIG_BT_HCIUART_AML
924 	aml_deinit();
925 #endif
926 	tty_unregister_ldisc(&hci_uart_ldisc);
927 }
928 
929 module_init(hci_uart_init);
930 module_exit(hci_uart_exit);
931 
932 MODULE_AUTHOR("Marcel Holtmann <[email protected]>");
933 MODULE_DESCRIPTION("Bluetooth HCI UART driver ver " VERSION);
934 MODULE_VERSION(VERSION);
935 MODULE_LICENSE("GPL");
936 MODULE_ALIAS_LDISC(N_HCI);
937