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
44#include <net/bluetooth/bluetooth.h>
45#include <net/bluetooth/hci_core.h>
46
47#include "btintel.h"
48#include "btbcm.h"
49#include "hci_uart.h"
50
51#define VERSION "2.3"
52
53static const struct hci_uart_proto *hup[HCI_UART_MAX_PROTO];
54
55int hci_uart_register_proto(const struct hci_uart_proto *p)
56{
57	if (p->id >= HCI_UART_MAX_PROTO)
58		return -EINVAL;
59
60	if (hup[p->id])
61		return -EEXIST;
62
63	hup[p->id] = p;
64
65	BT_INFO("HCI UART protocol %s registered", p->name);
66
67	return 0;
68}
69
70int hci_uart_unregister_proto(const struct hci_uart_proto *p)
71{
72	if (p->id >= HCI_UART_MAX_PROTO)
73		return -EINVAL;
74
75	if (!hup[p->id])
76		return -EINVAL;
77
78	hup[p->id] = NULL;
79
80	return 0;
81}
82
83static const struct hci_uart_proto *hci_uart_get_proto(unsigned int id)
84{
85	if (id >= HCI_UART_MAX_PROTO)
86		return NULL;
87
88	return hup[id];
89}
90
91static inline void hci_uart_tx_complete(struct hci_uart *hu, int pkt_type)
92{
93	struct hci_dev *hdev = hu->hdev;
94
95	/* Update HCI stat counters */
96	switch (pkt_type) {
97	case HCI_COMMAND_PKT:
98		hdev->stat.cmd_tx++;
99		break;
100
101	case HCI_ACLDATA_PKT:
102		hdev->stat.acl_tx++;
103		break;
104
105	case HCI_SCODATA_PKT:
106		hdev->stat.sco_tx++;
107		break;
108	}
109}
110
111static inline struct sk_buff *hci_uart_dequeue(struct hci_uart *hu)
112{
113	struct sk_buff *skb = hu->tx_skb;
114
115	if (!skb)
116		skb = hu->proto->dequeue(hu);
117	else
118		hu->tx_skb = NULL;
119
120	return skb;
121}
122
123int hci_uart_tx_wakeup(struct hci_uart *hu)
124{
125	if (test_and_set_bit(HCI_UART_SENDING, &hu->tx_state)) {
126		set_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
127		return 0;
128	}
129
130	BT_DBG("");
131
132	schedule_work(&hu->write_work);
133
134	return 0;
135}
136
137static void hci_uart_write_work(struct work_struct *work)
138{
139	struct hci_uart *hu = container_of(work, struct hci_uart, write_work);
140	struct tty_struct *tty = hu->tty;
141	struct hci_dev *hdev = hu->hdev;
142	struct sk_buff *skb;
143
144	/* REVISIT: should we cope with bad skbs or ->write() returning
145	 * and error value ?
146	 */
147
148restart:
149	clear_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
150
151	while ((skb = hci_uart_dequeue(hu))) {
152		int len;
153
154		set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
155		len = tty->ops->write(tty, skb->data, skb->len);
156		hdev->stat.byte_tx += len;
157
158		skb_pull(skb, len);
159		if (skb->len) {
160			hu->tx_skb = skb;
161			break;
162		}
163
164		hci_uart_tx_complete(hu, bt_cb(skb)->pkt_type);
165		kfree_skb(skb);
166	}
167
168	if (test_bit(HCI_UART_TX_WAKEUP, &hu->tx_state))
169		goto restart;
170
171	clear_bit(HCI_UART_SENDING, &hu->tx_state);
172}
173
174static void hci_uart_init_work(struct work_struct *work)
175{
176	struct hci_uart *hu = container_of(work, struct hci_uart, init_ready);
177	int err;
178
179	if (!test_and_clear_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
180		return;
181
182	err = hci_register_dev(hu->hdev);
183	if (err < 0) {
184		BT_ERR("Can't register HCI device");
185		hci_free_dev(hu->hdev);
186		hu->hdev = NULL;
187		hu->proto->close(hu);
188	}
189
190	set_bit(HCI_UART_REGISTERED, &hu->flags);
191}
192
193int hci_uart_init_ready(struct hci_uart *hu)
194{
195	if (!test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
196		return -EALREADY;
197
198	schedule_work(&hu->init_ready);
199
200	return 0;
201}
202
203/* ------- Interface to HCI layer ------ */
204/* Initialize device */
205static int hci_uart_open(struct hci_dev *hdev)
206{
207	BT_DBG("%s %p", hdev->name, hdev);
208
209	/* Nothing to do for UART driver */
210
211	set_bit(HCI_RUNNING, &hdev->flags);
212
213	return 0;
214}
215
216/* Reset device */
217static int hci_uart_flush(struct hci_dev *hdev)
218{
219	struct hci_uart *hu  = hci_get_drvdata(hdev);
220	struct tty_struct *tty = hu->tty;
221
222	BT_DBG("hdev %p tty %p", hdev, tty);
223
224	if (hu->tx_skb) {
225		kfree_skb(hu->tx_skb); hu->tx_skb = NULL;
226	}
227
228	/* Flush any pending characters in the driver and discipline. */
229	tty_ldisc_flush(tty);
230	tty_driver_flush_buffer(tty);
231
232	if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
233		hu->proto->flush(hu);
234
235	return 0;
236}
237
238/* Close device */
239static int hci_uart_close(struct hci_dev *hdev)
240{
241	BT_DBG("hdev %p", hdev);
242
243	if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags))
244		return 0;
245
246	hci_uart_flush(hdev);
247	hdev->flush = NULL;
248	return 0;
249}
250
251/* Send frames from HCI layer */
252static int hci_uart_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
253{
254	struct hci_uart *hu = hci_get_drvdata(hdev);
255
256	if (!test_bit(HCI_RUNNING, &hdev->flags))
257		return -EBUSY;
258
259	BT_DBG("%s: type %d len %d", hdev->name, bt_cb(skb)->pkt_type, skb->len);
260
261	hu->proto->enqueue(hu, skb);
262
263	hci_uart_tx_wakeup(hu);
264
265	return 0;
266}
267
268static int hci_uart_setup(struct hci_dev *hdev)
269{
270	struct hci_uart *hu = hci_get_drvdata(hdev);
271	struct hci_rp_read_local_version *ver;
272	struct sk_buff *skb;
273
274	if (hu->proto->setup)
275		return hu->proto->setup(hu);
276
277	if (!test_bit(HCI_UART_VND_DETECT, &hu->hdev_flags))
278		return 0;
279
280	skb = __hci_cmd_sync(hdev, HCI_OP_READ_LOCAL_VERSION, 0, NULL,
281			     HCI_INIT_TIMEOUT);
282	if (IS_ERR(skb)) {
283		BT_ERR("%s: Reading local version information failed (%ld)",
284		       hdev->name, PTR_ERR(skb));
285		return 0;
286	}
287
288	if (skb->len != sizeof(*ver)) {
289		BT_ERR("%s: Event length mismatch for version information",
290		       hdev->name);
291		goto done;
292	}
293
294	ver = (struct hci_rp_read_local_version *)skb->data;
295
296	switch (le16_to_cpu(ver->manufacturer)) {
297#ifdef CONFIG_BT_HCIUART_INTEL
298	case 2:
299		hdev->set_bdaddr = btintel_set_bdaddr;
300		btintel_check_bdaddr(hdev);
301		break;
302#endif
303#ifdef CONFIG_BT_HCIUART_BCM
304	case 15:
305		hdev->set_bdaddr = btbcm_set_bdaddr;
306		btbcm_check_bdaddr(hdev);
307		break;
308#endif
309	}
310
311done:
312	kfree_skb(skb);
313	return 0;
314}
315
316/* ------ LDISC part ------ */
317/* hci_uart_tty_open
318 *
319 *     Called when line discipline changed to HCI_UART.
320 *
321 * Arguments:
322 *     tty    pointer to tty info structure
323 * Return Value:
324 *     0 if success, otherwise error code
325 */
326static int hci_uart_tty_open(struct tty_struct *tty)
327{
328	struct hci_uart *hu;
329
330	BT_DBG("tty %p", tty);
331
332	/* Error if the tty has no write op instead of leaving an exploitable
333	   hole */
334	if (tty->ops->write == NULL)
335		return -EOPNOTSUPP;
336
337	hu = kzalloc(sizeof(struct hci_uart), GFP_KERNEL);
338	if (!hu) {
339		BT_ERR("Can't allocate control structure");
340		return -ENFILE;
341	}
342
343	tty->disc_data = hu;
344	hu->tty = tty;
345	tty->receive_room = 65536;
346
347	INIT_WORK(&hu->init_ready, hci_uart_init_work);
348	INIT_WORK(&hu->write_work, hci_uart_write_work);
349
350	spin_lock_init(&hu->rx_lock);
351
352	/* Flush any pending characters in the driver and line discipline. */
353
354	/* FIXME: why is this needed. Note don't use ldisc_ref here as the
355	   open path is before the ldisc is referencable */
356
357	if (tty->ldisc->ops->flush_buffer)
358		tty->ldisc->ops->flush_buffer(tty);
359	tty_driver_flush_buffer(tty);
360
361	return 0;
362}
363
364/* hci_uart_tty_close()
365 *
366 *    Called when the line discipline is changed to something
367 *    else, the tty is closed, or the tty detects a hangup.
368 */
369static void hci_uart_tty_close(struct tty_struct *tty)
370{
371	struct hci_uart *hu = tty->disc_data;
372	struct hci_dev *hdev;
373
374	BT_DBG("tty %p", tty);
375
376	/* Detach from the tty */
377	tty->disc_data = NULL;
378
379	if (!hu)
380		return;
381
382	hdev = hu->hdev;
383	if (hdev)
384		hci_uart_close(hdev);
385
386	cancel_work_sync(&hu->write_work);
387
388	if (test_and_clear_bit(HCI_UART_PROTO_SET, &hu->flags)) {
389		if (hdev) {
390			if (test_bit(HCI_UART_REGISTERED, &hu->flags))
391				hci_unregister_dev(hdev);
392			hci_free_dev(hdev);
393		}
394		hu->proto->close(hu);
395	}
396
397	kfree(hu);
398}
399
400/* hci_uart_tty_wakeup()
401 *
402 *    Callback for transmit wakeup. Called when low level
403 *    device driver can accept more send data.
404 *
405 * Arguments:        tty    pointer to associated tty instance data
406 * Return Value:    None
407 */
408static void hci_uart_tty_wakeup(struct tty_struct *tty)
409{
410	struct hci_uart *hu = tty->disc_data;
411
412	BT_DBG("");
413
414	if (!hu)
415		return;
416
417	clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
418
419	if (tty != hu->tty)
420		return;
421
422	if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
423		hci_uart_tx_wakeup(hu);
424}
425
426/* hci_uart_tty_receive()
427 *
428 *     Called by tty low level driver when receive data is
429 *     available.
430 *
431 * Arguments:  tty          pointer to tty isntance data
432 *             data         pointer to received data
433 *             flags        pointer to flags for data
434 *             count        count of received data in bytes
435 *
436 * Return Value:    None
437 */
438static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data,
439				 char *flags, int count)
440{
441	struct hci_uart *hu = tty->disc_data;
442
443	if (!hu || tty != hu->tty)
444		return;
445
446	if (!test_bit(HCI_UART_PROTO_SET, &hu->flags))
447		return;
448
449	spin_lock(&hu->rx_lock);
450	hu->proto->recv(hu, data, count);
451
452	if (hu->hdev)
453		hu->hdev->stat.byte_rx += count;
454
455	spin_unlock(&hu->rx_lock);
456
457	tty_unthrottle(tty);
458}
459
460static int hci_uart_register_dev(struct hci_uart *hu)
461{
462	struct hci_dev *hdev;
463
464	BT_DBG("");
465
466	/* Initialize and register HCI device */
467	hdev = hci_alloc_dev();
468	if (!hdev) {
469		BT_ERR("Can't allocate HCI device");
470		return -ENOMEM;
471	}
472
473	hu->hdev = hdev;
474
475	hdev->bus = HCI_UART;
476	hci_set_drvdata(hdev, hu);
477
478	hdev->open  = hci_uart_open;
479	hdev->close = hci_uart_close;
480	hdev->flush = hci_uart_flush;
481	hdev->send  = hci_uart_send_frame;
482	hdev->setup = hci_uart_setup;
483	SET_HCIDEV_DEV(hdev, hu->tty->dev);
484
485	if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags))
486		set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
487
488	if (test_bit(HCI_UART_EXT_CONFIG, &hu->hdev_flags))
489		set_bit(HCI_QUIRK_EXTERNAL_CONFIG, &hdev->quirks);
490
491	if (!test_bit(HCI_UART_RESET_ON_INIT, &hu->hdev_flags))
492		set_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks);
493
494	if (test_bit(HCI_UART_CREATE_AMP, &hu->hdev_flags))
495		hdev->dev_type = HCI_AMP;
496	else
497		hdev->dev_type = HCI_BREDR;
498
499	if (test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
500		return 0;
501
502	if (hci_register_dev(hdev) < 0) {
503		BT_ERR("Can't register HCI device");
504		hci_free_dev(hdev);
505		return -ENODEV;
506	}
507
508	set_bit(HCI_UART_REGISTERED, &hu->flags);
509
510	return 0;
511}
512
513static int hci_uart_set_proto(struct hci_uart *hu, int id)
514{
515	const struct hci_uart_proto *p;
516	int err;
517
518	p = hci_uart_get_proto(id);
519	if (!p)
520		return -EPROTONOSUPPORT;
521
522	err = p->open(hu);
523	if (err)
524		return err;
525
526	hu->proto = p;
527
528	err = hci_uart_register_dev(hu);
529	if (err) {
530		p->close(hu);
531		return err;
532	}
533
534	return 0;
535}
536
537static int hci_uart_set_flags(struct hci_uart *hu, unsigned long flags)
538{
539	unsigned long valid_flags = BIT(HCI_UART_RAW_DEVICE) |
540				    BIT(HCI_UART_RESET_ON_INIT) |
541				    BIT(HCI_UART_CREATE_AMP) |
542				    BIT(HCI_UART_INIT_PENDING) |
543				    BIT(HCI_UART_EXT_CONFIG) |
544				    BIT(HCI_UART_VND_DETECT);
545
546	if (flags & ~valid_flags)
547		return -EINVAL;
548
549	hu->hdev_flags = flags;
550
551	return 0;
552}
553
554/* hci_uart_tty_ioctl()
555 *
556 *    Process IOCTL system call for the tty device.
557 *
558 * Arguments:
559 *
560 *    tty        pointer to tty instance data
561 *    file       pointer to open file object for device
562 *    cmd        IOCTL command code
563 *    arg        argument for IOCTL call (cmd dependent)
564 *
565 * Return Value:    Command dependent
566 */
567static int hci_uart_tty_ioctl(struct tty_struct *tty, struct file *file,
568			      unsigned int cmd, unsigned long arg)
569{
570	struct hci_uart *hu = tty->disc_data;
571	int err = 0;
572
573	BT_DBG("");
574
575	/* Verify the status of the device */
576	if (!hu)
577		return -EBADF;
578
579	switch (cmd) {
580	case HCIUARTSETPROTO:
581		if (!test_and_set_bit(HCI_UART_PROTO_SET, &hu->flags)) {
582			err = hci_uart_set_proto(hu, arg);
583			if (err) {
584				clear_bit(HCI_UART_PROTO_SET, &hu->flags);
585				return err;
586			}
587		} else
588			return -EBUSY;
589		break;
590
591	case HCIUARTGETPROTO:
592		if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
593			return hu->proto->id;
594		return -EUNATCH;
595
596	case HCIUARTGETDEVICE:
597		if (test_bit(HCI_UART_REGISTERED, &hu->flags))
598			return hu->hdev->id;
599		return -EUNATCH;
600
601	case HCIUARTSETFLAGS:
602		if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
603			return -EBUSY;
604		err = hci_uart_set_flags(hu, arg);
605		if (err)
606			return err;
607		break;
608
609	case HCIUARTGETFLAGS:
610		return hu->hdev_flags;
611
612	default:
613		err = n_tty_ioctl_helper(tty, file, cmd, arg);
614		break;
615	}
616
617	return err;
618}
619
620/*
621 * We don't provide read/write/poll interface for user space.
622 */
623static ssize_t hci_uart_tty_read(struct tty_struct *tty, struct file *file,
624				 unsigned char __user *buf, size_t nr)
625{
626	return 0;
627}
628
629static ssize_t hci_uart_tty_write(struct tty_struct *tty, struct file *file,
630				  const unsigned char *data, size_t count)
631{
632	return 0;
633}
634
635static unsigned int hci_uart_tty_poll(struct tty_struct *tty,
636				      struct file *filp, poll_table *wait)
637{
638	return 0;
639}
640
641static int __init hci_uart_init(void)
642{
643	static struct tty_ldisc_ops hci_uart_ldisc;
644	int err;
645
646	BT_INFO("HCI UART driver ver %s", VERSION);
647
648	/* Register the tty discipline */
649
650	memset(&hci_uart_ldisc, 0, sizeof (hci_uart_ldisc));
651	hci_uart_ldisc.magic		= TTY_LDISC_MAGIC;
652	hci_uart_ldisc.name		= "n_hci";
653	hci_uart_ldisc.open		= hci_uart_tty_open;
654	hci_uart_ldisc.close		= hci_uart_tty_close;
655	hci_uart_ldisc.read		= hci_uart_tty_read;
656	hci_uart_ldisc.write		= hci_uart_tty_write;
657	hci_uart_ldisc.ioctl		= hci_uart_tty_ioctl;
658	hci_uart_ldisc.poll		= hci_uart_tty_poll;
659	hci_uart_ldisc.receive_buf	= hci_uart_tty_receive;
660	hci_uart_ldisc.write_wakeup	= hci_uart_tty_wakeup;
661	hci_uart_ldisc.owner		= THIS_MODULE;
662
663	err = tty_register_ldisc(N_HCI, &hci_uart_ldisc);
664	if (err) {
665		BT_ERR("HCI line discipline registration failed. (%d)", err);
666		return err;
667	}
668
669#ifdef CONFIG_BT_HCIUART_H4
670	h4_init();
671#endif
672#ifdef CONFIG_BT_HCIUART_BCSP
673	bcsp_init();
674#endif
675#ifdef CONFIG_BT_HCIUART_LL
676	ll_init();
677#endif
678#ifdef CONFIG_BT_HCIUART_ATH3K
679	ath_init();
680#endif
681#ifdef CONFIG_BT_HCIUART_3WIRE
682	h5_init();
683#endif
684#ifdef CONFIG_BT_HCIUART_BCM
685	bcm_init();
686#endif
687
688	return 0;
689}
690
691static void __exit hci_uart_exit(void)
692{
693	int err;
694
695#ifdef CONFIG_BT_HCIUART_H4
696	h4_deinit();
697#endif
698#ifdef CONFIG_BT_HCIUART_BCSP
699	bcsp_deinit();
700#endif
701#ifdef CONFIG_BT_HCIUART_LL
702	ll_deinit();
703#endif
704#ifdef CONFIG_BT_HCIUART_ATH3K
705	ath_deinit();
706#endif
707#ifdef CONFIG_BT_HCIUART_3WIRE
708	h5_deinit();
709#endif
710#ifdef CONFIG_BT_HCIUART_BCM
711	bcm_deinit();
712#endif
713
714	/* Release tty registration of line discipline */
715	err = tty_unregister_ldisc(N_HCI);
716	if (err)
717		BT_ERR("Can't unregister HCI line discipline (%d)", err);
718}
719
720module_init(hci_uart_init);
721module_exit(hci_uart_exit);
722
723MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
724MODULE_DESCRIPTION("Bluetooth HCI UART driver ver " VERSION);
725MODULE_VERSION(VERSION);
726MODULE_LICENSE("GPL");
727MODULE_ALIAS_LDISC(N_HCI);
728