hci_ldisc.c

  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
 40static const struct hci_uart_proto *hup[HCI_UART_MAX_PROTO];
 41
 42int 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
 57int 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
 70static 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
 78static 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
 98static 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
117int 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
140no_schedule:
141	percpu_up_read(&hu->proto_lock);
142
143	return 0;
144}
145EXPORT_SYMBOL_GPL(hci_uart_tx_wakeup);
146
147static 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
158restart:
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
185void 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
208int 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
218int 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 */
227static 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 */
253static 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 */
264static 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 */
274static 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 */
298bool 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 */
311void 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
369void 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
376void 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
392static 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
464done:
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 */
479static 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 */
530static 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 */
577static 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 */
608static 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
636static 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		hci_set_quirk(hdev, HCI_QUIRK_RAW_DEVICE);
671
672	if (test_bit(HCI_UART_EXT_CONFIG, &hu->hdev_flags))
673		hci_set_quirk(hdev, HCI_QUIRK_EXTERNAL_CONFIG);
674
675	if (!test_bit(HCI_UART_RESET_ON_INIT, &hu->hdev_flags))
676		hci_set_quirk(hdev, HCI_QUIRK_RESET_ON_CLOSE);
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	set_bit(HCI_UART_PROTO_INIT, &hu->flags);
689
690	if (test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
691		return 0;
692
693	if (hci_register_dev(hdev) < 0) {
694		BT_ERR("Can't register HCI device");
695		hu->proto->close(hu);
696		hu->hdev = NULL;
697		hci_free_dev(hdev);
698		return -ENODEV;
699	}
700
701	set_bit(HCI_UART_REGISTERED, &hu->flags);
702
703	return 0;
704}
705
706static int hci_uart_set_proto(struct hci_uart *hu, int id)
707{
708	const struct hci_uart_proto *p;
709	int err;
710
711	p = hci_uart_get_proto(id);
712	if (!p)
713		return -EPROTONOSUPPORT;
714
715	hu->proto = p;
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
728static 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 */
756static 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 */
815static 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
822static 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
828static 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
842static 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
891static 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
929module_init(hci_uart_init);
930module_exit(hci_uart_exit);
931
932MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
933MODULE_DESCRIPTION("Bluetooth HCI UART driver ver " VERSION);
934MODULE_VERSION(VERSION);
935MODULE_LICENSE("GPL");
936MODULE_ALIAS_LDISC(N_HCI);