xref: /openbmc/linux/drivers/bluetooth/hci_ldisc.c (revision addee42a)
1 /*
2  *
3  *  Bluetooth HCI UART driver
4  *
5  *  Copyright (C) 2000-2001  Qualcomm Incorporated
6  *  Copyright (C) 2002-2003  Maxim Krasnyansky <maxk@qualcomm.com>
7  *  Copyright (C) 2004-2005  Marcel Holtmann <marcel@holtmann.org>
8  *
9  *
10  *  This program is free software; you can redistribute it and/or modify
11  *  it under the terms of the GNU General Public License as published by
12  *  the Free Software Foundation; either version 2 of the License, or
13  *  (at your option) any later version.
14  *
15  *  This program is distributed in the hope that it will be useful,
16  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
17  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  *  GNU General Public License for more details.
19  *
20  *  You should have received a copy of the GNU General Public License
21  *  along with this program; if not, write to the Free Software
22  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
23  *
24  */
25 
26 #include <linux/module.h>
27 
28 #include <linux/kernel.h>
29 #include <linux/init.h>
30 #include <linux/types.h>
31 #include <linux/fcntl.h>
32 #include <linux/interrupt.h>
33 #include <linux/ptrace.h>
34 #include <linux/poll.h>
35 
36 #include <linux/slab.h>
37 #include <linux/tty.h>
38 #include <linux/errno.h>
39 #include <linux/string.h>
40 #include <linux/signal.h>
41 #include <linux/ioctl.h>
42 #include <linux/skbuff.h>
43 #include <linux/firmware.h>
44 #include <linux/serdev.h>
45 
46 #include <net/bluetooth/bluetooth.h>
47 #include <net/bluetooth/hci_core.h>
48 
49 #include "btintel.h"
50 #include "btbcm.h"
51 #include "hci_uart.h"
52 
53 #define VERSION "2.3"
54 
55 static const struct hci_uart_proto *hup[HCI_UART_MAX_PROTO];
56 
57 int hci_uart_register_proto(const struct hci_uart_proto *p)
58 {
59 	if (p->id >= HCI_UART_MAX_PROTO)
60 		return -EINVAL;
61 
62 	if (hup[p->id])
63 		return -EEXIST;
64 
65 	hup[p->id] = p;
66 
67 	BT_INFO("HCI UART protocol %s registered", p->name);
68 
69 	return 0;
70 }
71 
72 int hci_uart_unregister_proto(const struct hci_uart_proto *p)
73 {
74 	if (p->id >= HCI_UART_MAX_PROTO)
75 		return -EINVAL;
76 
77 	if (!hup[p->id])
78 		return -EINVAL;
79 
80 	hup[p->id] = NULL;
81 
82 	return 0;
83 }
84 
85 static const struct hci_uart_proto *hci_uart_get_proto(unsigned int id)
86 {
87 	if (id >= HCI_UART_MAX_PROTO)
88 		return NULL;
89 
90 	return hup[id];
91 }
92 
93 static inline void hci_uart_tx_complete(struct hci_uart *hu, int pkt_type)
94 {
95 	struct hci_dev *hdev = hu->hdev;
96 
97 	/* Update HCI stat counters */
98 	switch (pkt_type) {
99 	case HCI_COMMAND_PKT:
100 		hdev->stat.cmd_tx++;
101 		break;
102 
103 	case HCI_ACLDATA_PKT:
104 		hdev->stat.acl_tx++;
105 		break;
106 
107 	case HCI_SCODATA_PKT:
108 		hdev->stat.sco_tx++;
109 		break;
110 	}
111 }
112 
113 static inline struct sk_buff *hci_uart_dequeue(struct hci_uart *hu)
114 {
115 	struct sk_buff *skb = hu->tx_skb;
116 
117 	if (!skb) {
118 		percpu_down_read(&hu->proto_lock);
119 
120 		if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
121 			skb = hu->proto->dequeue(hu);
122 
123 		percpu_up_read(&hu->proto_lock);
124 	} else {
125 		hu->tx_skb = NULL;
126 	}
127 
128 	return skb;
129 }
130 
131 int hci_uart_tx_wakeup(struct hci_uart *hu)
132 {
133 	/* This may be called in an IRQ context, so we can't sleep. Therefore
134 	 * we try to acquire the lock only, and if that fails we assume the
135 	 * tty is being closed because that is the only time the write lock is
136 	 * acquired. If, however, at some point in the future the write lock
137 	 * is also acquired in other situations, then this must be revisited.
138 	 */
139 	if (!percpu_down_read_trylock(&hu->proto_lock))
140 		return 0;
141 
142 	if (!test_bit(HCI_UART_PROTO_READY, &hu->flags))
143 		goto no_schedule;
144 
145 	if (test_and_set_bit(HCI_UART_SENDING, &hu->tx_state)) {
146 		set_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
147 		goto no_schedule;
148 	}
149 
150 	BT_DBG("");
151 
152 	schedule_work(&hu->write_work);
153 
154 no_schedule:
155 	percpu_up_read(&hu->proto_lock);
156 
157 	return 0;
158 }
159 EXPORT_SYMBOL_GPL(hci_uart_tx_wakeup);
160 
161 static void hci_uart_write_work(struct work_struct *work)
162 {
163 	struct hci_uart *hu = container_of(work, struct hci_uart, write_work);
164 	struct tty_struct *tty = hu->tty;
165 	struct hci_dev *hdev = hu->hdev;
166 	struct sk_buff *skb;
167 
168 	/* REVISIT: should we cope with bad skbs or ->write() returning
169 	 * and error value ?
170 	 */
171 
172 restart:
173 	clear_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
174 
175 	while ((skb = hci_uart_dequeue(hu))) {
176 		int len;
177 
178 		set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
179 		len = tty->ops->write(tty, skb->data, skb->len);
180 		hdev->stat.byte_tx += len;
181 
182 		skb_pull(skb, len);
183 		if (skb->len) {
184 			hu->tx_skb = skb;
185 			break;
186 		}
187 
188 		hci_uart_tx_complete(hu, hci_skb_pkt_type(skb));
189 		kfree_skb(skb);
190 	}
191 
192 	if (test_bit(HCI_UART_TX_WAKEUP, &hu->tx_state))
193 		goto restart;
194 
195 	clear_bit(HCI_UART_SENDING, &hu->tx_state);
196 }
197 
198 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 		hdev = hu->hdev;
211 		hu->hdev = NULL;
212 		hci_free_dev(hdev);
213 		clear_bit(HCI_UART_PROTO_READY, &hu->flags);
214 		hu->proto->close(hu);
215 		return;
216 	}
217 
218 	set_bit(HCI_UART_REGISTERED, &hu->flags);
219 }
220 
221 int hci_uart_init_ready(struct hci_uart *hu)
222 {
223 	if (!test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
224 		return -EALREADY;
225 
226 	schedule_work(&hu->init_ready);
227 
228 	return 0;
229 }
230 
231 /* ------- Interface to HCI layer ------ */
232 /* Initialize device */
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 */
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 */
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 */
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 /* Flow control or un-flow control the device */
301 void hci_uart_set_flow_control(struct hci_uart *hu, bool enable)
302 {
303 	struct tty_struct *tty = hu->tty;
304 	struct ktermios ktermios;
305 	int status;
306 	unsigned int set = 0;
307 	unsigned int clear = 0;
308 
309 	if (hu->serdev) {
310 		serdev_device_set_flow_control(hu->serdev, !enable);
311 		serdev_device_set_rts(hu->serdev, !enable);
312 		return;
313 	}
314 
315 	if (enable) {
316 		/* Disable hardware flow control */
317 		ktermios = tty->termios;
318 		ktermios.c_cflag &= ~CRTSCTS;
319 		status = tty_set_termios(tty, &ktermios);
320 		BT_DBG("Disabling hardware flow control: %s",
321 		       status ? "failed" : "success");
322 
323 		/* Clear RTS to prevent the device from sending */
324 		/* Most UARTs need OUT2 to enable interrupts */
325 		status = tty->driver->ops->tiocmget(tty);
326 		BT_DBG("Current tiocm 0x%x", status);
327 
328 		set &= ~(TIOCM_OUT2 | TIOCM_RTS);
329 		clear = ~set;
330 		set &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
331 		       TIOCM_OUT2 | TIOCM_LOOP;
332 		clear &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
333 			 TIOCM_OUT2 | TIOCM_LOOP;
334 		status = tty->driver->ops->tiocmset(tty, set, clear);
335 		BT_DBG("Clearing RTS: %s", status ? "failed" : "success");
336 	} else {
337 		/* Set RTS to allow the device to send again */
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("Setting RTS: %s", status ? "failed" : "success");
349 
350 		/* Re-enable hardware flow control */
351 		ktermios = tty->termios;
352 		ktermios.c_cflag |= CRTSCTS;
353 		status = tty_set_termios(tty, &ktermios);
354 		BT_DBG("Enabling hardware flow control: %s",
355 		       status ? "failed" : "success");
356 	}
357 }
358 
359 void hci_uart_set_speeds(struct hci_uart *hu, unsigned int init_speed,
360 			 unsigned int oper_speed)
361 {
362 	hu->init_speed = init_speed;
363 	hu->oper_speed = oper_speed;
364 }
365 
366 void hci_uart_set_baudrate(struct hci_uart *hu, unsigned int speed)
367 {
368 	struct tty_struct *tty = hu->tty;
369 	struct ktermios ktermios;
370 
371 	ktermios = tty->termios;
372 	ktermios.c_cflag &= ~CBAUD;
373 	tty_termios_encode_baud_rate(&ktermios, speed, speed);
374 
375 	/* tty_set_termios() return not checked as it is always 0 */
376 	tty_set_termios(tty, &ktermios);
377 
378 	BT_DBG("%s: New tty speeds: %d/%d", hu->hdev->name,
379 	       tty->termios.c_ispeed, tty->termios.c_ospeed);
380 }
381 
382 static int hci_uart_setup(struct hci_dev *hdev)
383 {
384 	struct hci_uart *hu = hci_get_drvdata(hdev);
385 	struct hci_rp_read_local_version *ver;
386 	struct sk_buff *skb;
387 	unsigned int speed;
388 	int err;
389 
390 	/* Init speed if any */
391 	if (hu->init_speed)
392 		speed = hu->init_speed;
393 	else if (hu->proto->init_speed)
394 		speed = hu->proto->init_speed;
395 	else
396 		speed = 0;
397 
398 	if (speed)
399 		hci_uart_set_baudrate(hu, speed);
400 
401 	/* Operational speed if any */
402 	if (hu->oper_speed)
403 		speed = hu->oper_speed;
404 	else if (hu->proto->oper_speed)
405 		speed = hu->proto->oper_speed;
406 	else
407 		speed = 0;
408 
409 	if (hu->proto->set_baudrate && speed) {
410 		err = hu->proto->set_baudrate(hu, speed);
411 		if (!err)
412 			hci_uart_set_baudrate(hu, speed);
413 	}
414 
415 	if (hu->proto->setup)
416 		return hu->proto->setup(hu);
417 
418 	if (!test_bit(HCI_UART_VND_DETECT, &hu->hdev_flags))
419 		return 0;
420 
421 	skb = __hci_cmd_sync(hdev, HCI_OP_READ_LOCAL_VERSION, 0, NULL,
422 			     HCI_INIT_TIMEOUT);
423 	if (IS_ERR(skb)) {
424 		BT_ERR("%s: Reading local version information failed (%ld)",
425 		       hdev->name, PTR_ERR(skb));
426 		return 0;
427 	}
428 
429 	if (skb->len != sizeof(*ver)) {
430 		BT_ERR("%s: Event length mismatch for version information",
431 		       hdev->name);
432 		goto done;
433 	}
434 
435 	ver = (struct hci_rp_read_local_version *)skb->data;
436 
437 	switch (le16_to_cpu(ver->manufacturer)) {
438 #ifdef CONFIG_BT_HCIUART_INTEL
439 	case 2:
440 		hdev->set_bdaddr = btintel_set_bdaddr;
441 		btintel_check_bdaddr(hdev);
442 		break;
443 #endif
444 #ifdef CONFIG_BT_HCIUART_BCM
445 	case 15:
446 		hdev->set_bdaddr = btbcm_set_bdaddr;
447 		btbcm_check_bdaddr(hdev);
448 		break;
449 #endif
450 	}
451 
452 done:
453 	kfree_skb(skb);
454 	return 0;
455 }
456 
457 /* ------ LDISC part ------ */
458 /* hci_uart_tty_open
459  *
460  *     Called when line discipline changed to HCI_UART.
461  *
462  * Arguments:
463  *     tty    pointer to tty info structure
464  * Return Value:
465  *     0 if success, otherwise error code
466  */
467 static int hci_uart_tty_open(struct tty_struct *tty)
468 {
469 	struct hci_uart *hu;
470 
471 	BT_DBG("tty %p", tty);
472 
473 	/* Error if the tty has no write op instead of leaving an exploitable
474 	 * hole
475 	 */
476 	if (tty->ops->write == NULL)
477 		return -EOPNOTSUPP;
478 
479 	hu = kzalloc(sizeof(struct hci_uart), GFP_KERNEL);
480 	if (!hu) {
481 		BT_ERR("Can't allocate control structure");
482 		return -ENFILE;
483 	}
484 
485 	tty->disc_data = hu;
486 	hu->tty = tty;
487 	tty->receive_room = 65536;
488 
489 	/* disable alignment support by default */
490 	hu->alignment = 1;
491 	hu->padding = 0;
492 
493 	INIT_WORK(&hu->init_ready, hci_uart_init_work);
494 	INIT_WORK(&hu->write_work, hci_uart_write_work);
495 
496 	percpu_init_rwsem(&hu->proto_lock);
497 
498 	/* Flush any pending characters in the driver */
499 	tty_driver_flush_buffer(tty);
500 
501 	return 0;
502 }
503 
504 /* hci_uart_tty_close()
505  *
506  *    Called when the line discipline is changed to something
507  *    else, the tty is closed, or the tty detects a hangup.
508  */
509 static void hci_uart_tty_close(struct tty_struct *tty)
510 {
511 	struct hci_uart *hu = tty->disc_data;
512 	struct hci_dev *hdev;
513 
514 	BT_DBG("tty %p", tty);
515 
516 	/* Detach from the tty */
517 	tty->disc_data = NULL;
518 
519 	if (!hu)
520 		return;
521 
522 	hdev = hu->hdev;
523 	if (hdev)
524 		hci_uart_close(hdev);
525 
526 	if (test_bit(HCI_UART_PROTO_READY, &hu->flags)) {
527 		percpu_down_write(&hu->proto_lock);
528 		clear_bit(HCI_UART_PROTO_READY, &hu->flags);
529 		percpu_up_write(&hu->proto_lock);
530 
531 		cancel_work_sync(&hu->write_work);
532 
533 		if (hdev) {
534 			if (test_bit(HCI_UART_REGISTERED, &hu->flags))
535 				hci_unregister_dev(hdev);
536 			hci_free_dev(hdev);
537 		}
538 		hu->proto->close(hu);
539 	}
540 	clear_bit(HCI_UART_PROTO_SET, &hu->flags);
541 
542 	kfree(hu);
543 }
544 
545 /* hci_uart_tty_wakeup()
546  *
547  *    Callback for transmit wakeup. Called when low level
548  *    device driver can accept more send data.
549  *
550  * Arguments:        tty    pointer to associated tty instance data
551  * Return Value:    None
552  */
553 static void hci_uart_tty_wakeup(struct tty_struct *tty)
554 {
555 	struct hci_uart *hu = tty->disc_data;
556 
557 	BT_DBG("");
558 
559 	if (!hu)
560 		return;
561 
562 	clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
563 
564 	if (tty != hu->tty)
565 		return;
566 
567 	if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
568 		hci_uart_tx_wakeup(hu);
569 }
570 
571 /* hci_uart_tty_receive()
572  *
573  *     Called by tty low level driver when receive data is
574  *     available.
575  *
576  * Arguments:  tty          pointer to tty isntance data
577  *             data         pointer to received data
578  *             flags        pointer to flags for data
579  *             count        count of received data in bytes
580  *
581  * Return Value:    None
582  */
583 static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data,
584 				 char *flags, int count)
585 {
586 	struct hci_uart *hu = tty->disc_data;
587 
588 	if (!hu || tty != hu->tty)
589 		return;
590 
591 	percpu_down_read(&hu->proto_lock);
592 
593 	if (!test_bit(HCI_UART_PROTO_READY, &hu->flags)) {
594 		percpu_up_read(&hu->proto_lock);
595 		return;
596 	}
597 
598 	/* It does not need a lock here as it is already protected by a mutex in
599 	 * tty caller
600 	 */
601 	hu->proto->recv(hu, data, count);
602 	percpu_up_read(&hu->proto_lock);
603 
604 	if (hu->hdev)
605 		hu->hdev->stat.byte_rx += count;
606 
607 	tty_unthrottle(tty);
608 }
609 
610 static int hci_uart_register_dev(struct hci_uart *hu)
611 {
612 	struct hci_dev *hdev;
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 	if (test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
657 		return 0;
658 
659 	if (hci_register_dev(hdev) < 0) {
660 		BT_ERR("Can't register HCI device");
661 		hu->hdev = NULL;
662 		hci_free_dev(hdev);
663 		return -ENODEV;
664 	}
665 
666 	set_bit(HCI_UART_REGISTERED, &hu->flags);
667 
668 	return 0;
669 }
670 
671 static int hci_uart_set_proto(struct hci_uart *hu, int id)
672 {
673 	const struct hci_uart_proto *p;
674 	int err;
675 
676 	p = hci_uart_get_proto(id);
677 	if (!p)
678 		return -EPROTONOSUPPORT;
679 
680 	err = p->open(hu);
681 	if (err)
682 		return err;
683 
684 	hu->proto = p;
685 	set_bit(HCI_UART_PROTO_READY, &hu->flags);
686 
687 	err = hci_uart_register_dev(hu);
688 	if (err) {
689 		clear_bit(HCI_UART_PROTO_READY, &hu->flags);
690 		p->close(hu);
691 		return err;
692 	}
693 
694 	return 0;
695 }
696 
697 static int hci_uart_set_flags(struct hci_uart *hu, unsigned long flags)
698 {
699 	unsigned long valid_flags = BIT(HCI_UART_RAW_DEVICE) |
700 				    BIT(HCI_UART_RESET_ON_INIT) |
701 				    BIT(HCI_UART_CREATE_AMP) |
702 				    BIT(HCI_UART_INIT_PENDING) |
703 				    BIT(HCI_UART_EXT_CONFIG) |
704 				    BIT(HCI_UART_VND_DETECT);
705 
706 	if (flags & ~valid_flags)
707 		return -EINVAL;
708 
709 	hu->hdev_flags = flags;
710 
711 	return 0;
712 }
713 
714 /* hci_uart_tty_ioctl()
715  *
716  *    Process IOCTL system call for the tty device.
717  *
718  * Arguments:
719  *
720  *    tty        pointer to tty instance data
721  *    file       pointer to open file object for device
722  *    cmd        IOCTL command code
723  *    arg        argument for IOCTL call (cmd dependent)
724  *
725  * Return Value:    Command dependent
726  */
727 static int hci_uart_tty_ioctl(struct tty_struct *tty, struct file *file,
728 			      unsigned int cmd, unsigned long arg)
729 {
730 	struct hci_uart *hu = tty->disc_data;
731 	int err = 0;
732 
733 	BT_DBG("");
734 
735 	/* Verify the status of the device */
736 	if (!hu)
737 		return -EBADF;
738 
739 	switch (cmd) {
740 	case HCIUARTSETPROTO:
741 		if (!test_and_set_bit(HCI_UART_PROTO_SET, &hu->flags)) {
742 			err = hci_uart_set_proto(hu, arg);
743 			if (err)
744 				clear_bit(HCI_UART_PROTO_SET, &hu->flags);
745 		} else
746 			err = -EBUSY;
747 		break;
748 
749 	case HCIUARTGETPROTO:
750 		if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
751 			err = hu->proto->id;
752 		else
753 			err = -EUNATCH;
754 		break;
755 
756 	case HCIUARTGETDEVICE:
757 		if (test_bit(HCI_UART_REGISTERED, &hu->flags))
758 			err = hu->hdev->id;
759 		else
760 			err = -EUNATCH;
761 		break;
762 
763 	case HCIUARTSETFLAGS:
764 		if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
765 			err = -EBUSY;
766 		else
767 			err = hci_uart_set_flags(hu, arg);
768 		break;
769 
770 	case HCIUARTGETFLAGS:
771 		err = hu->hdev_flags;
772 		break;
773 
774 	default:
775 		err = n_tty_ioctl_helper(tty, file, cmd, arg);
776 		break;
777 	}
778 
779 	return err;
780 }
781 
782 /*
783  * We don't provide read/write/poll interface for user space.
784  */
785 static ssize_t hci_uart_tty_read(struct tty_struct *tty, struct file *file,
786 				 unsigned char __user *buf, size_t nr)
787 {
788 	return 0;
789 }
790 
791 static ssize_t hci_uart_tty_write(struct tty_struct *tty, struct file *file,
792 				  const unsigned char *data, size_t count)
793 {
794 	return 0;
795 }
796 
797 static __poll_t hci_uart_tty_poll(struct tty_struct *tty,
798 				      struct file *filp, poll_table *wait)
799 {
800 	return 0;
801 }
802 
803 static int __init hci_uart_init(void)
804 {
805 	static struct tty_ldisc_ops hci_uart_ldisc;
806 	int err;
807 
808 	BT_INFO("HCI UART driver ver %s", VERSION);
809 
810 	/* Register the tty discipline */
811 
812 	memset(&hci_uart_ldisc, 0, sizeof(hci_uart_ldisc));
813 	hci_uart_ldisc.magic		= TTY_LDISC_MAGIC;
814 	hci_uart_ldisc.name		= "n_hci";
815 	hci_uart_ldisc.open		= hci_uart_tty_open;
816 	hci_uart_ldisc.close		= hci_uart_tty_close;
817 	hci_uart_ldisc.read		= hci_uart_tty_read;
818 	hci_uart_ldisc.write		= hci_uart_tty_write;
819 	hci_uart_ldisc.ioctl		= hci_uart_tty_ioctl;
820 	hci_uart_ldisc.poll		= hci_uart_tty_poll;
821 	hci_uart_ldisc.receive_buf	= hci_uart_tty_receive;
822 	hci_uart_ldisc.write_wakeup	= hci_uart_tty_wakeup;
823 	hci_uart_ldisc.owner		= THIS_MODULE;
824 
825 	err = tty_register_ldisc(N_HCI, &hci_uart_ldisc);
826 	if (err) {
827 		BT_ERR("HCI line discipline registration failed. (%d)", err);
828 		return err;
829 	}
830 
831 #ifdef CONFIG_BT_HCIUART_H4
832 	h4_init();
833 #endif
834 #ifdef CONFIG_BT_HCIUART_BCSP
835 	bcsp_init();
836 #endif
837 #ifdef CONFIG_BT_HCIUART_LL
838 	ll_init();
839 #endif
840 #ifdef CONFIG_BT_HCIUART_ATH3K
841 	ath_init();
842 #endif
843 #ifdef CONFIG_BT_HCIUART_3WIRE
844 	h5_init();
845 #endif
846 #ifdef CONFIG_BT_HCIUART_INTEL
847 	intel_init();
848 #endif
849 #ifdef CONFIG_BT_HCIUART_BCM
850 	bcm_init();
851 #endif
852 #ifdef CONFIG_BT_HCIUART_QCA
853 	qca_init();
854 #endif
855 #ifdef CONFIG_BT_HCIUART_AG6XX
856 	ag6xx_init();
857 #endif
858 #ifdef CONFIG_BT_HCIUART_MRVL
859 	mrvl_init();
860 #endif
861 
862 	return 0;
863 }
864 
865 static void __exit hci_uart_exit(void)
866 {
867 	int err;
868 
869 #ifdef CONFIG_BT_HCIUART_H4
870 	h4_deinit();
871 #endif
872 #ifdef CONFIG_BT_HCIUART_BCSP
873 	bcsp_deinit();
874 #endif
875 #ifdef CONFIG_BT_HCIUART_LL
876 	ll_deinit();
877 #endif
878 #ifdef CONFIG_BT_HCIUART_ATH3K
879 	ath_deinit();
880 #endif
881 #ifdef CONFIG_BT_HCIUART_3WIRE
882 	h5_deinit();
883 #endif
884 #ifdef CONFIG_BT_HCIUART_INTEL
885 	intel_deinit();
886 #endif
887 #ifdef CONFIG_BT_HCIUART_BCM
888 	bcm_deinit();
889 #endif
890 #ifdef CONFIG_BT_HCIUART_QCA
891 	qca_deinit();
892 #endif
893 #ifdef CONFIG_BT_HCIUART_AG6XX
894 	ag6xx_deinit();
895 #endif
896 #ifdef CONFIG_BT_HCIUART_MRVL
897 	mrvl_deinit();
898 #endif
899 
900 	/* Release tty registration of line discipline */
901 	err = tty_unregister_ldisc(N_HCI);
902 	if (err)
903 		BT_ERR("Can't unregister HCI line discipline (%d)", err);
904 }
905 
906 module_init(hci_uart_init);
907 module_exit(hci_uart_exit);
908 
909 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
910 MODULE_DESCRIPTION("Bluetooth HCI UART driver ver " VERSION);
911 MODULE_VERSION(VERSION);
912 MODULE_LICENSE("GPL");
913 MODULE_ALIAS_LDISC(N_HCI);
914