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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 
hci_uart_register_proto(const struct hci_uart_proto * p)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 
hci_uart_unregister_proto(const struct hci_uart_proto * p)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 
hci_uart_get_proto(unsigned int id)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 
hci_uart_tx_complete(struct hci_uart * hu,int pkt_type)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 
hci_uart_dequeue(struct hci_uart * hu)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 
hci_uart_tx_wakeup(struct hci_uart * hu)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 
hci_uart_write_work(struct work_struct * work)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 
hci_uart_init_work(struct work_struct * work)198 static 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 		clear_bit(HCI_UART_PROTO_READY, &hu->flags);
211 		hu->proto->close(hu);
212 		hdev = hu->hdev;
213 		hu->hdev = NULL;
214 		hci_free_dev(hdev);
215 		return;
216 	}
217 
218 	set_bit(HCI_UART_REGISTERED, &hu->flags);
219 }
220 
hci_uart_init_ready(struct hci_uart * hu)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 /* Initialize device */
hci_uart_open(struct hci_dev * hdev)233 static int hci_uart_open(struct hci_dev *hdev)
234 {
235 	BT_DBG("%s %p", hdev->name, hdev);
236 
237 	/* Nothing to do for UART driver */
238 	return 0;
239 }
240 
241 /* Reset device */
hci_uart_flush(struct hci_dev * hdev)242 static int hci_uart_flush(struct hci_dev *hdev)
243 {
244 	struct hci_uart *hu  = hci_get_drvdata(hdev);
245 	struct tty_struct *tty = hu->tty;
246 
247 	BT_DBG("hdev %p tty %p", hdev, tty);
248 
249 	if (hu->tx_skb) {
250 		kfree_skb(hu->tx_skb); hu->tx_skb = NULL;
251 	}
252 
253 	/* Flush any pending characters in the driver and discipline. */
254 	tty_ldisc_flush(tty);
255 	tty_driver_flush_buffer(tty);
256 
257 	percpu_down_read(&hu->proto_lock);
258 
259 	if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
260 		hu->proto->flush(hu);
261 
262 	percpu_up_read(&hu->proto_lock);
263 
264 	return 0;
265 }
266 
267 /* Close device */
hci_uart_close(struct hci_dev * hdev)268 static int hci_uart_close(struct hci_dev *hdev)
269 {
270 	BT_DBG("hdev %p", hdev);
271 
272 	hci_uart_flush(hdev);
273 	hdev->flush = NULL;
274 	return 0;
275 }
276 
277 /* Send frames from HCI layer */
hci_uart_send_frame(struct hci_dev * hdev,struct sk_buff * skb)278 static int hci_uart_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
279 {
280 	struct hci_uart *hu = hci_get_drvdata(hdev);
281 
282 	BT_DBG("%s: type %d len %d", hdev->name, hci_skb_pkt_type(skb),
283 	       skb->len);
284 
285 	percpu_down_read(&hu->proto_lock);
286 
287 	if (!test_bit(HCI_UART_PROTO_READY, &hu->flags)) {
288 		percpu_up_read(&hu->proto_lock);
289 		return -EUNATCH;
290 	}
291 
292 	hu->proto->enqueue(hu, skb);
293 	percpu_up_read(&hu->proto_lock);
294 
295 	hci_uart_tx_wakeup(hu);
296 
297 	return 0;
298 }
299 
300 /* Check the underlying device or tty has flow control support */
hci_uart_has_flow_control(struct hci_uart * hu)301 bool hci_uart_has_flow_control(struct hci_uart *hu)
302 {
303 	/* serdev nodes check if the needed operations are present */
304 	if (hu->serdev)
305 		return true;
306 
307 	if (hu->tty->driver->ops->tiocmget && hu->tty->driver->ops->tiocmset)
308 		return true;
309 
310 	return false;
311 }
312 
313 /* Flow control or un-flow control the device */
hci_uart_set_flow_control(struct hci_uart * hu,bool enable)314 void hci_uart_set_flow_control(struct hci_uart *hu, bool enable)
315 {
316 	struct tty_struct *tty = hu->tty;
317 	struct ktermios ktermios;
318 	int status;
319 	unsigned int set = 0;
320 	unsigned int clear = 0;
321 
322 	if (hu->serdev) {
323 		serdev_device_set_flow_control(hu->serdev, !enable);
324 		serdev_device_set_rts(hu->serdev, !enable);
325 		return;
326 	}
327 
328 	if (enable) {
329 		/* Disable hardware flow control */
330 		ktermios = tty->termios;
331 		ktermios.c_cflag &= ~CRTSCTS;
332 		status = tty_set_termios(tty, &ktermios);
333 		BT_DBG("Disabling hardware flow control: %s",
334 		       status ? "failed" : "success");
335 
336 		/* Clear RTS to prevent the device from sending */
337 		/* Most UARTs need OUT2 to enable interrupts */
338 		status = tty->driver->ops->tiocmget(tty);
339 		BT_DBG("Current tiocm 0x%x", status);
340 
341 		set &= ~(TIOCM_OUT2 | TIOCM_RTS);
342 		clear = ~set;
343 		set &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
344 		       TIOCM_OUT2 | TIOCM_LOOP;
345 		clear &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
346 			 TIOCM_OUT2 | TIOCM_LOOP;
347 		status = tty->driver->ops->tiocmset(tty, set, clear);
348 		BT_DBG("Clearing RTS: %s", status ? "failed" : "success");
349 	} else {
350 		/* Set RTS to allow the device to send again */
351 		status = tty->driver->ops->tiocmget(tty);
352 		BT_DBG("Current tiocm 0x%x", status);
353 
354 		set |= (TIOCM_OUT2 | TIOCM_RTS);
355 		clear = ~set;
356 		set &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
357 		       TIOCM_OUT2 | TIOCM_LOOP;
358 		clear &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
359 			 TIOCM_OUT2 | TIOCM_LOOP;
360 		status = tty->driver->ops->tiocmset(tty, set, clear);
361 		BT_DBG("Setting RTS: %s", status ? "failed" : "success");
362 
363 		/* Re-enable hardware flow control */
364 		ktermios = tty->termios;
365 		ktermios.c_cflag |= CRTSCTS;
366 		status = tty_set_termios(tty, &ktermios);
367 		BT_DBG("Enabling hardware flow control: %s",
368 		       status ? "failed" : "success");
369 	}
370 }
371 
hci_uart_set_speeds(struct hci_uart * hu,unsigned int init_speed,unsigned int oper_speed)372 void hci_uart_set_speeds(struct hci_uart *hu, unsigned int init_speed,
373 			 unsigned int oper_speed)
374 {
375 	hu->init_speed = init_speed;
376 	hu->oper_speed = oper_speed;
377 }
378 
hci_uart_set_baudrate(struct hci_uart * hu,unsigned int speed)379 void hci_uart_set_baudrate(struct hci_uart *hu, unsigned int speed)
380 {
381 	struct tty_struct *tty = hu->tty;
382 	struct ktermios ktermios;
383 
384 	ktermios = tty->termios;
385 	ktermios.c_cflag &= ~CBAUD;
386 	tty_termios_encode_baud_rate(&ktermios, speed, speed);
387 
388 	/* tty_set_termios() return not checked as it is always 0 */
389 	tty_set_termios(tty, &ktermios);
390 
391 	BT_DBG("%s: New tty speeds: %d/%d", hu->hdev->name,
392 	       tty->termios.c_ispeed, tty->termios.c_ospeed);
393 }
394 
hci_uart_setup(struct hci_dev * hdev)395 static int hci_uart_setup(struct hci_dev *hdev)
396 {
397 	struct hci_uart *hu = hci_get_drvdata(hdev);
398 	struct hci_rp_read_local_version *ver;
399 	struct sk_buff *skb;
400 	unsigned int speed;
401 	int err;
402 
403 	/* Init speed if any */
404 	if (hu->init_speed)
405 		speed = hu->init_speed;
406 	else if (hu->proto->init_speed)
407 		speed = hu->proto->init_speed;
408 	else
409 		speed = 0;
410 
411 	if (speed)
412 		hci_uart_set_baudrate(hu, speed);
413 
414 	/* Operational speed if any */
415 	if (hu->oper_speed)
416 		speed = hu->oper_speed;
417 	else if (hu->proto->oper_speed)
418 		speed = hu->proto->oper_speed;
419 	else
420 		speed = 0;
421 
422 	if (hu->proto->set_baudrate && speed) {
423 		err = hu->proto->set_baudrate(hu, speed);
424 		if (!err)
425 			hci_uart_set_baudrate(hu, speed);
426 	}
427 
428 	if (hu->proto->setup)
429 		return hu->proto->setup(hu);
430 
431 	if (!test_bit(HCI_UART_VND_DETECT, &hu->hdev_flags))
432 		return 0;
433 
434 	skb = __hci_cmd_sync(hdev, HCI_OP_READ_LOCAL_VERSION, 0, NULL,
435 			     HCI_INIT_TIMEOUT);
436 	if (IS_ERR(skb)) {
437 		BT_ERR("%s: Reading local version information failed (%ld)",
438 		       hdev->name, PTR_ERR(skb));
439 		return 0;
440 	}
441 
442 	if (skb->len != sizeof(*ver)) {
443 		BT_ERR("%s: Event length mismatch for version information",
444 		       hdev->name);
445 		goto done;
446 	}
447 
448 	ver = (struct hci_rp_read_local_version *)skb->data;
449 
450 	switch (le16_to_cpu(ver->manufacturer)) {
451 #ifdef CONFIG_BT_HCIUART_INTEL
452 	case 2:
453 		hdev->set_bdaddr = btintel_set_bdaddr;
454 		btintel_check_bdaddr(hdev);
455 		break;
456 #endif
457 #ifdef CONFIG_BT_HCIUART_BCM
458 	case 15:
459 		hdev->set_bdaddr = btbcm_set_bdaddr;
460 		btbcm_check_bdaddr(hdev);
461 		break;
462 #endif
463 	}
464 
465 done:
466 	kfree_skb(skb);
467 	return 0;
468 }
469 
470 /* ------ LDISC part ------ */
471 /* hci_uart_tty_open
472  *
473  *     Called when line discipline changed to HCI_UART.
474  *
475  * Arguments:
476  *     tty    pointer to tty info structure
477  * Return Value:
478  *     0 if success, otherwise error code
479  */
hci_uart_tty_open(struct tty_struct * tty)480 static int hci_uart_tty_open(struct tty_struct *tty)
481 {
482 	struct hci_uart *hu;
483 
484 	BT_DBG("tty %p", tty);
485 
486 	/* Error if the tty has no write op instead of leaving an exploitable
487 	 * hole
488 	 */
489 	if (tty->ops->write == NULL)
490 		return -EOPNOTSUPP;
491 
492 	hu = kzalloc(sizeof(struct hci_uart), GFP_KERNEL);
493 	if (!hu) {
494 		BT_ERR("Can't allocate control structure");
495 		return -ENFILE;
496 	}
497 
498 	tty->disc_data = hu;
499 	hu->tty = tty;
500 	tty->receive_room = 65536;
501 
502 	/* disable alignment support by default */
503 	hu->alignment = 1;
504 	hu->padding = 0;
505 
506 	INIT_WORK(&hu->init_ready, hci_uart_init_work);
507 	INIT_WORK(&hu->write_work, hci_uart_write_work);
508 
509 	percpu_init_rwsem(&hu->proto_lock);
510 
511 	/* Flush any pending characters in the driver */
512 	tty_driver_flush_buffer(tty);
513 
514 	return 0;
515 }
516 
517 /* hci_uart_tty_close()
518  *
519  *    Called when the line discipline is changed to something
520  *    else, the tty is closed, or the tty detects a hangup.
521  */
hci_uart_tty_close(struct tty_struct * tty)522 static void hci_uart_tty_close(struct tty_struct *tty)
523 {
524 	struct hci_uart *hu = tty->disc_data;
525 	struct hci_dev *hdev;
526 
527 	BT_DBG("tty %p", tty);
528 
529 	/* Detach from the tty */
530 	tty->disc_data = NULL;
531 
532 	if (!hu)
533 		return;
534 
535 	hdev = hu->hdev;
536 	if (hdev)
537 		hci_uart_close(hdev);
538 
539 	if (test_bit(HCI_UART_PROTO_READY, &hu->flags)) {
540 		percpu_down_write(&hu->proto_lock);
541 		clear_bit(HCI_UART_PROTO_READY, &hu->flags);
542 		percpu_up_write(&hu->proto_lock);
543 
544 		cancel_work_sync(&hu->write_work);
545 
546 		if (hdev) {
547 			if (test_bit(HCI_UART_REGISTERED, &hu->flags))
548 				hci_unregister_dev(hdev);
549 			hci_free_dev(hdev);
550 		}
551 		hu->proto->close(hu);
552 	}
553 	clear_bit(HCI_UART_PROTO_SET, &hu->flags);
554 
555 	percpu_free_rwsem(&hu->proto_lock);
556 
557 	kfree(hu);
558 }
559 
560 /* hci_uart_tty_wakeup()
561  *
562  *    Callback for transmit wakeup. Called when low level
563  *    device driver can accept more send data.
564  *
565  * Arguments:        tty    pointer to associated tty instance data
566  * Return Value:    None
567  */
hci_uart_tty_wakeup(struct tty_struct * tty)568 static void hci_uart_tty_wakeup(struct tty_struct *tty)
569 {
570 	struct hci_uart *hu = tty->disc_data;
571 
572 	BT_DBG("");
573 
574 	if (!hu)
575 		return;
576 
577 	clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
578 
579 	if (tty != hu->tty)
580 		return;
581 
582 	if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
583 		hci_uart_tx_wakeup(hu);
584 }
585 
586 /* hci_uart_tty_receive()
587  *
588  *     Called by tty low level driver when receive data is
589  *     available.
590  *
591  * Arguments:  tty          pointer to tty isntance data
592  *             data         pointer to received data
593  *             flags        pointer to flags for data
594  *             count        count of received data in bytes
595  *
596  * Return Value:    None
597  */
hci_uart_tty_receive(struct tty_struct * tty,const u8 * data,char * flags,int count)598 static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data,
599 				 char *flags, int count)
600 {
601 	struct hci_uart *hu = tty->disc_data;
602 
603 	if (!hu || tty != hu->tty)
604 		return;
605 
606 	percpu_down_read(&hu->proto_lock);
607 
608 	if (!test_bit(HCI_UART_PROTO_READY, &hu->flags)) {
609 		percpu_up_read(&hu->proto_lock);
610 		return;
611 	}
612 
613 	/* It does not need a lock here as it is already protected by a mutex in
614 	 * tty caller
615 	 */
616 	hu->proto->recv(hu, data, count);
617 	percpu_up_read(&hu->proto_lock);
618 
619 	if (hu->hdev)
620 		hu->hdev->stat.byte_rx += count;
621 
622 	tty_unthrottle(tty);
623 }
624 
hci_uart_register_dev(struct hci_uart * hu)625 static int hci_uart_register_dev(struct hci_uart *hu)
626 {
627 	struct hci_dev *hdev;
628 	int err;
629 
630 	BT_DBG("");
631 
632 	/* Initialize and register HCI device */
633 	hdev = hci_alloc_dev();
634 	if (!hdev) {
635 		BT_ERR("Can't allocate HCI device");
636 		return -ENOMEM;
637 	}
638 
639 	hu->hdev = hdev;
640 
641 	hdev->bus = HCI_UART;
642 	hci_set_drvdata(hdev, hu);
643 
644 	/* Only when vendor specific setup callback is provided, consider
645 	 * the manufacturer information valid. This avoids filling in the
646 	 * value for Ericsson when nothing is specified.
647 	 */
648 	if (hu->proto->setup)
649 		hdev->manufacturer = hu->proto->manufacturer;
650 
651 	hdev->open  = hci_uart_open;
652 	hdev->close = hci_uart_close;
653 	hdev->flush = hci_uart_flush;
654 	hdev->send  = hci_uart_send_frame;
655 	hdev->setup = hci_uart_setup;
656 	SET_HCIDEV_DEV(hdev, hu->tty->dev);
657 
658 	if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags))
659 		set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
660 
661 	if (test_bit(HCI_UART_EXT_CONFIG, &hu->hdev_flags))
662 		set_bit(HCI_QUIRK_EXTERNAL_CONFIG, &hdev->quirks);
663 
664 	if (!test_bit(HCI_UART_RESET_ON_INIT, &hu->hdev_flags))
665 		set_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks);
666 
667 	if (test_bit(HCI_UART_CREATE_AMP, &hu->hdev_flags))
668 		hdev->dev_type = HCI_AMP;
669 	else
670 		hdev->dev_type = HCI_PRIMARY;
671 
672 	/* Only call open() for the protocol after hdev is fully initialized as
673 	 * open() (or a timer/workqueue it starts) may attempt to reference it.
674 	 */
675 	err = hu->proto->open(hu);
676 	if (err) {
677 		hu->hdev = NULL;
678 		hci_free_dev(hdev);
679 		return err;
680 	}
681 
682 	if (test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
683 		return 0;
684 
685 	if (hci_register_dev(hdev) < 0) {
686 		BT_ERR("Can't register HCI device");
687 		hu->proto->close(hu);
688 		hu->hdev = NULL;
689 		hci_free_dev(hdev);
690 		return -ENODEV;
691 	}
692 
693 	set_bit(HCI_UART_REGISTERED, &hu->flags);
694 
695 	return 0;
696 }
697 
hci_uart_set_proto(struct hci_uart * hu,int id)698 static int hci_uart_set_proto(struct hci_uart *hu, int id)
699 {
700 	const struct hci_uart_proto *p;
701 	int err;
702 
703 	p = hci_uart_get_proto(id);
704 	if (!p)
705 		return -EPROTONOSUPPORT;
706 
707 	hu->proto = p;
708 
709 	err = hci_uart_register_dev(hu);
710 	if (err) {
711 		return err;
712 	}
713 
714 	set_bit(HCI_UART_PROTO_READY, &hu->flags);
715 	return 0;
716 }
717 
hci_uart_set_flags(struct hci_uart * hu,unsigned long flags)718 static int hci_uart_set_flags(struct hci_uart *hu, unsigned long flags)
719 {
720 	unsigned long valid_flags = BIT(HCI_UART_RAW_DEVICE) |
721 				    BIT(HCI_UART_RESET_ON_INIT) |
722 				    BIT(HCI_UART_CREATE_AMP) |
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  *    file       pointer to open file object for device
743  *    cmd        IOCTL command code
744  *    arg        argument for IOCTL call (cmd dependent)
745  *
746  * Return Value:    Command dependent
747  */
hci_uart_tty_ioctl(struct tty_struct * tty,struct file * file,unsigned int cmd,unsigned long arg)748 static int hci_uart_tty_ioctl(struct tty_struct *tty, struct file *file,
749 			      unsigned int cmd, unsigned long arg)
750 {
751 	struct hci_uart *hu = tty->disc_data;
752 	int err = 0;
753 
754 	BT_DBG("");
755 
756 	/* Verify the status of the device */
757 	if (!hu)
758 		return -EBADF;
759 
760 	switch (cmd) {
761 	case HCIUARTSETPROTO:
762 		if (!test_and_set_bit(HCI_UART_PROTO_SET, &hu->flags)) {
763 			err = hci_uart_set_proto(hu, arg);
764 			if (err)
765 				clear_bit(HCI_UART_PROTO_SET, &hu->flags);
766 		} else
767 			err = -EBUSY;
768 		break;
769 
770 	case HCIUARTGETPROTO:
771 		if (test_bit(HCI_UART_PROTO_SET, &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, file, 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,unsigned char __user * buf,size_t nr)806 static ssize_t hci_uart_tty_read(struct tty_struct *tty, struct file *file,
807 				 unsigned char __user *buf, size_t nr)
808 {
809 	return 0;
810 }
811 
hci_uart_tty_write(struct tty_struct * tty,struct file * file,const unsigned char * data,size_t count)812 static ssize_t hci_uart_tty_write(struct tty_struct *tty, struct file *file,
813 				  const unsigned char *data, size_t count)
814 {
815 	return 0;
816 }
817 
hci_uart_tty_poll(struct tty_struct * tty,struct file * filp,poll_table * wait)818 static unsigned int hci_uart_tty_poll(struct tty_struct *tty,
819 				      struct file *filp, poll_table *wait)
820 {
821 	return 0;
822 }
823 
hci_uart_init(void)824 static int __init hci_uart_init(void)
825 {
826 	static struct tty_ldisc_ops hci_uart_ldisc;
827 	int err;
828 
829 	BT_INFO("HCI UART driver ver %s", VERSION);
830 
831 	/* Register the tty discipline */
832 
833 	memset(&hci_uart_ldisc, 0, sizeof(hci_uart_ldisc));
834 	hci_uart_ldisc.magic		= TTY_LDISC_MAGIC;
835 	hci_uart_ldisc.name		= "n_hci";
836 	hci_uart_ldisc.open		= hci_uart_tty_open;
837 	hci_uart_ldisc.close		= hci_uart_tty_close;
838 	hci_uart_ldisc.read		= hci_uart_tty_read;
839 	hci_uart_ldisc.write		= hci_uart_tty_write;
840 	hci_uart_ldisc.ioctl		= hci_uart_tty_ioctl;
841 	hci_uart_ldisc.poll		= hci_uart_tty_poll;
842 	hci_uart_ldisc.receive_buf	= hci_uart_tty_receive;
843 	hci_uart_ldisc.write_wakeup	= hci_uart_tty_wakeup;
844 	hci_uart_ldisc.owner		= THIS_MODULE;
845 
846 	err = tty_register_ldisc(N_HCI, &hci_uart_ldisc);
847 	if (err) {
848 		BT_ERR("HCI line discipline registration failed. (%d)", err);
849 		return err;
850 	}
851 
852 #ifdef CONFIG_BT_HCIUART_H4
853 	h4_init();
854 #endif
855 #ifdef CONFIG_BT_HCIUART_BCSP
856 	bcsp_init();
857 #endif
858 #ifdef CONFIG_BT_HCIUART_LL
859 	ll_init();
860 #endif
861 #ifdef CONFIG_BT_HCIUART_ATH3K
862 	ath_init();
863 #endif
864 #ifdef CONFIG_BT_HCIUART_3WIRE
865 	h5_init();
866 #endif
867 #ifdef CONFIG_BT_HCIUART_INTEL
868 	intel_init();
869 #endif
870 #ifdef CONFIG_BT_HCIUART_BCM
871 	bcm_init();
872 #endif
873 #ifdef CONFIG_BT_HCIUART_QCA
874 	qca_init();
875 #endif
876 #ifdef CONFIG_BT_HCIUART_AG6XX
877 	ag6xx_init();
878 #endif
879 #ifdef CONFIG_BT_HCIUART_MRVL
880 	mrvl_init();
881 #endif
882 
883 	return 0;
884 }
885 
hci_uart_exit(void)886 static void __exit hci_uart_exit(void)
887 {
888 	int err;
889 
890 #ifdef CONFIG_BT_HCIUART_H4
891 	h4_deinit();
892 #endif
893 #ifdef CONFIG_BT_HCIUART_BCSP
894 	bcsp_deinit();
895 #endif
896 #ifdef CONFIG_BT_HCIUART_LL
897 	ll_deinit();
898 #endif
899 #ifdef CONFIG_BT_HCIUART_ATH3K
900 	ath_deinit();
901 #endif
902 #ifdef CONFIG_BT_HCIUART_3WIRE
903 	h5_deinit();
904 #endif
905 #ifdef CONFIG_BT_HCIUART_INTEL
906 	intel_deinit();
907 #endif
908 #ifdef CONFIG_BT_HCIUART_BCM
909 	bcm_deinit();
910 #endif
911 #ifdef CONFIG_BT_HCIUART_QCA
912 	qca_deinit();
913 #endif
914 #ifdef CONFIG_BT_HCIUART_AG6XX
915 	ag6xx_deinit();
916 #endif
917 #ifdef CONFIG_BT_HCIUART_MRVL
918 	mrvl_deinit();
919 #endif
920 
921 	/* Release tty registration of line discipline */
922 	err = tty_unregister_ldisc(N_HCI);
923 	if (err)
924 		BT_ERR("Can't unregister HCI line discipline (%d)", err);
925 }
926 
927 module_init(hci_uart_init);
928 module_exit(hci_uart_exit);
929 
930 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
931 MODULE_DESCRIPTION("Bluetooth HCI UART driver ver " VERSION);
932 MODULE_VERSION(VERSION);
933 MODULE_LICENSE("GPL");
934 MODULE_ALIAS_LDISC(N_HCI);
935