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 "hci_uart.h"
48
49 #define VERSION "2.2"
50
51 static struct hci_uart_proto *hup[HCI_UART_MAX_PROTO];
52
hci_uart_register_proto(struct hci_uart_proto * p)53 int hci_uart_register_proto(struct hci_uart_proto *p)
54 {
55 if (p->id >= HCI_UART_MAX_PROTO)
56 return -EINVAL;
57
58 if (hup[p->id])
59 return -EEXIST;
60
61 hup[p->id] = p;
62
63 return 0;
64 }
65
hci_uart_unregister_proto(struct hci_uart_proto * p)66 int hci_uart_unregister_proto(struct hci_uart_proto *p)
67 {
68 if (p->id >= HCI_UART_MAX_PROTO)
69 return -EINVAL;
70
71 if (!hup[p->id])
72 return -EINVAL;
73
74 hup[p->id] = NULL;
75
76 return 0;
77 }
78
hci_uart_get_proto(unsigned int id)79 static struct hci_uart_proto *hci_uart_get_proto(unsigned int id)
80 {
81 if (id >= HCI_UART_MAX_PROTO)
82 return NULL;
83
84 return hup[id];
85 }
86
hci_uart_tx_complete(struct hci_uart * hu,int pkt_type)87 static inline void hci_uart_tx_complete(struct hci_uart *hu, int pkt_type)
88 {
89 struct hci_dev *hdev = hu->hdev;
90
91 /* Update HCI stat counters */
92 switch (pkt_type) {
93 case HCI_COMMAND_PKT:
94 hdev->stat.cmd_tx++;
95 break;
96
97 case HCI_ACLDATA_PKT:
98 hdev->stat.acl_tx++;
99 break;
100
101 case HCI_SCODATA_PKT:
102 hdev->stat.sco_tx++;
103 break;
104 }
105 }
106
hci_uart_dequeue(struct hci_uart * hu)107 static inline struct sk_buff *hci_uart_dequeue(struct hci_uart *hu)
108 {
109 struct sk_buff *skb = hu->tx_skb;
110
111 if (!skb)
112 skb = hu->proto->dequeue(hu);
113 else
114 hu->tx_skb = NULL;
115
116 return skb;
117 }
118
hci_uart_tx_wakeup(struct hci_uart * hu)119 int hci_uart_tx_wakeup(struct hci_uart *hu)
120 {
121 struct tty_struct *tty = hu->tty;
122 struct hci_dev *hdev = hu->hdev;
123 struct sk_buff *skb;
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 restart:
133 clear_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
134
135 while ((skb = hci_uart_dequeue(hu))) {
136 int len;
137
138 set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
139 len = tty->ops->write(tty, skb->data, skb->len);
140 hdev->stat.byte_tx += len;
141
142 skb_pull(skb, len);
143 if (skb->len) {
144 hu->tx_skb = skb;
145 break;
146 }
147
148 hci_uart_tx_complete(hu, bt_cb(skb)->pkt_type);
149 kfree_skb(skb);
150 }
151
152 if (test_bit(HCI_UART_TX_WAKEUP, &hu->tx_state))
153 goto restart;
154
155 clear_bit(HCI_UART_SENDING, &hu->tx_state);
156 return 0;
157 }
158
159 /* ------- Interface to HCI layer ------ */
160 /* Initialize device */
hci_uart_open(struct hci_dev * hdev)161 static int hci_uart_open(struct hci_dev *hdev)
162 {
163 BT_DBG("%s %p", hdev->name, hdev);
164
165 /* Nothing to do for UART driver */
166
167 set_bit(HCI_RUNNING, &hdev->flags);
168
169 return 0;
170 }
171
172 /* Reset device */
hci_uart_flush(struct hci_dev * hdev)173 static int hci_uart_flush(struct hci_dev *hdev)
174 {
175 struct hci_uart *hu = hci_get_drvdata(hdev);
176 struct tty_struct *tty = hu->tty;
177
178 BT_DBG("hdev %p tty %p", hdev, tty);
179
180 if (hu->tx_skb) {
181 kfree_skb(hu->tx_skb); hu->tx_skb = NULL;
182 }
183
184 /* Flush any pending characters in the driver and discipline. */
185 tty_ldisc_flush(tty);
186 tty_driver_flush_buffer(tty);
187
188 if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
189 hu->proto->flush(hu);
190
191 return 0;
192 }
193
194 /* Close device */
hci_uart_close(struct hci_dev * hdev)195 static int hci_uart_close(struct hci_dev *hdev)
196 {
197 BT_DBG("hdev %p", hdev);
198
199 if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags))
200 return 0;
201
202 hci_uart_flush(hdev);
203 hdev->flush = NULL;
204 return 0;
205 }
206
207 /* Send frames from HCI layer */
hci_uart_send_frame(struct sk_buff * skb)208 static int hci_uart_send_frame(struct sk_buff *skb)
209 {
210 struct hci_dev* hdev = (struct hci_dev *) skb->dev;
211 struct hci_uart *hu;
212
213 if (!hdev) {
214 BT_ERR("Frame for unknown device (hdev=NULL)");
215 return -ENODEV;
216 }
217
218 if (!test_bit(HCI_RUNNING, &hdev->flags))
219 return -EBUSY;
220
221 hu = hci_get_drvdata(hdev);
222
223 BT_DBG("%s: type %d len %d", hdev->name, bt_cb(skb)->pkt_type, skb->len);
224
225 hu->proto->enqueue(hu, skb);
226
227 hci_uart_tx_wakeup(hu);
228
229 return 0;
230 }
231
232 /* ------ LDISC part ------ */
233 /* hci_uart_tty_open
234 *
235 * Called when line discipline changed to HCI_UART.
236 *
237 * Arguments:
238 * tty pointer to tty info structure
239 * Return Value:
240 * 0 if success, otherwise error code
241 */
hci_uart_tty_open(struct tty_struct * tty)242 static int hci_uart_tty_open(struct tty_struct *tty)
243 {
244 struct hci_uart *hu = (void *) tty->disc_data;
245
246 BT_DBG("tty %p", tty);
247
248 /* FIXME: This btw is bogus, nothing requires the old ldisc to clear
249 the pointer */
250 if (hu)
251 return -EEXIST;
252
253 /* Error if the tty has no write op instead of leaving an exploitable
254 hole */
255 if (tty->ops->write == NULL)
256 return -EOPNOTSUPP;
257
258 if (!(hu = kzalloc(sizeof(struct hci_uart), GFP_KERNEL))) {
259 BT_ERR("Can't allocate control structure");
260 return -ENFILE;
261 }
262
263 tty->disc_data = hu;
264 hu->tty = tty;
265 tty->receive_room = 65536;
266
267 spin_lock_init(&hu->rx_lock);
268
269 /* Flush any pending characters in the driver and line discipline. */
270
271 /* FIXME: why is this needed. Note don't use ldisc_ref here as the
272 open path is before the ldisc is referencable */
273
274 if (tty->ldisc->ops->flush_buffer)
275 tty->ldisc->ops->flush_buffer(tty);
276 tty_driver_flush_buffer(tty);
277
278 return 0;
279 }
280
281 /* hci_uart_tty_close()
282 *
283 * Called when the line discipline is changed to something
284 * else, the tty is closed, or the tty detects a hangup.
285 */
hci_uart_tty_close(struct tty_struct * tty)286 static void hci_uart_tty_close(struct tty_struct *tty)
287 {
288 struct hci_uart *hu = (void *)tty->disc_data;
289
290 BT_DBG("tty %p", tty);
291
292 /* Detach from the tty */
293 tty->disc_data = NULL;
294
295 if (hu) {
296 struct hci_dev *hdev = hu->hdev;
297
298 if (hdev)
299 hci_uart_close(hdev);
300
301 if (test_and_clear_bit(HCI_UART_PROTO_SET, &hu->flags)) {
302 if (hdev) {
303 hci_unregister_dev(hdev);
304 hci_free_dev(hdev);
305 }
306 hu->proto->close(hu);
307 }
308
309 kfree(hu);
310 }
311 }
312
313 /* hci_uart_tty_wakeup()
314 *
315 * Callback for transmit wakeup. Called when low level
316 * device driver can accept more send data.
317 *
318 * Arguments: tty pointer to associated tty instance data
319 * Return Value: None
320 */
hci_uart_tty_wakeup(struct tty_struct * tty)321 static void hci_uart_tty_wakeup(struct tty_struct *tty)
322 {
323 struct hci_uart *hu = (void *)tty->disc_data;
324
325 BT_DBG("");
326
327 if (!hu)
328 return;
329
330 clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
331
332 if (tty != hu->tty)
333 return;
334
335 if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
336 hci_uart_tx_wakeup(hu);
337 }
338
339 /* hci_uart_tty_receive()
340 *
341 * Called by tty low level driver when receive data is
342 * available.
343 *
344 * Arguments: tty pointer to tty isntance data
345 * data pointer to received data
346 * flags pointer to flags for data
347 * count count of received data in bytes
348 *
349 * Return Value: None
350 */
hci_uart_tty_receive(struct tty_struct * tty,const u8 * data,char * flags,int count)351 static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data, char *flags, int count)
352 {
353 struct hci_uart *hu = (void *)tty->disc_data;
354
355 if (!hu || tty != hu->tty)
356 return;
357
358 if (!test_bit(HCI_UART_PROTO_SET, &hu->flags))
359 return;
360
361 spin_lock(&hu->rx_lock);
362 hu->proto->recv(hu, (void *) data, count);
363 hu->hdev->stat.byte_rx += count;
364 spin_unlock(&hu->rx_lock);
365
366 tty_unthrottle(tty);
367 }
368
hci_uart_register_dev(struct hci_uart * hu)369 static int hci_uart_register_dev(struct hci_uart *hu)
370 {
371 struct hci_dev *hdev;
372
373 BT_DBG("");
374
375 /* Initialize and register HCI device */
376 hdev = hci_alloc_dev();
377 if (!hdev) {
378 BT_ERR("Can't allocate HCI device");
379 return -ENOMEM;
380 }
381
382 hu->hdev = hdev;
383
384 hdev->bus = HCI_UART;
385 hci_set_drvdata(hdev, hu);
386
387 hdev->open = hci_uart_open;
388 hdev->close = hci_uart_close;
389 hdev->flush = hci_uart_flush;
390 hdev->send = hci_uart_send_frame;
391 hdev->parent = hu->tty->dev;
392
393 if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags))
394 set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
395
396 if (!test_bit(HCI_UART_RESET_ON_INIT, &hu->hdev_flags))
397 set_bit(HCI_QUIRK_NO_RESET, &hdev->quirks);
398
399 if (test_bit(HCI_UART_CREATE_AMP, &hu->hdev_flags))
400 hdev->dev_type = HCI_AMP;
401 else
402 hdev->dev_type = HCI_BREDR;
403
404 if (hci_register_dev(hdev) < 0) {
405 BT_ERR("Can't register HCI device");
406 hci_free_dev(hdev);
407 return -ENODEV;
408 }
409
410 return 0;
411 }
412
hci_uart_set_proto(struct hci_uart * hu,int id)413 static int hci_uart_set_proto(struct hci_uart *hu, int id)
414 {
415 struct hci_uart_proto *p;
416 int err;
417
418 p = hci_uart_get_proto(id);
419 if (!p)
420 return -EPROTONOSUPPORT;
421
422 err = p->open(hu);
423 if (err)
424 return err;
425
426 hu->proto = p;
427
428 err = hci_uart_register_dev(hu);
429 if (err) {
430 p->close(hu);
431 return err;
432 }
433
434 return 0;
435 }
436
437 /* hci_uart_tty_ioctl()
438 *
439 * Process IOCTL system call for the tty device.
440 *
441 * Arguments:
442 *
443 * tty pointer to tty instance data
444 * file pointer to open file object for device
445 * cmd IOCTL command code
446 * arg argument for IOCTL call (cmd dependent)
447 *
448 * Return Value: Command dependent
449 */
hci_uart_tty_ioctl(struct tty_struct * tty,struct file * file,unsigned int cmd,unsigned long arg)450 static int hci_uart_tty_ioctl(struct tty_struct *tty, struct file * file,
451 unsigned int cmd, unsigned long arg)
452 {
453 struct hci_uart *hu = (void *)tty->disc_data;
454 int err = 0;
455
456 BT_DBG("");
457
458 /* Verify the status of the device */
459 if (!hu)
460 return -EBADF;
461
462 switch (cmd) {
463 case HCIUARTSETPROTO:
464 if (!test_and_set_bit(HCI_UART_PROTO_SET, &hu->flags)) {
465 err = hci_uart_set_proto(hu, arg);
466 if (err) {
467 clear_bit(HCI_UART_PROTO_SET, &hu->flags);
468 return err;
469 }
470 } else
471 return -EBUSY;
472 break;
473
474 case HCIUARTGETPROTO:
475 if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
476 return hu->proto->id;
477 return -EUNATCH;
478
479 case HCIUARTGETDEVICE:
480 if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
481 return hu->hdev->id;
482 return -EUNATCH;
483
484 case HCIUARTSETFLAGS:
485 if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
486 return -EBUSY;
487 hu->hdev_flags = arg;
488 break;
489
490 case HCIUARTGETFLAGS:
491 return hu->hdev_flags;
492
493 default:
494 err = n_tty_ioctl_helper(tty, file, cmd, arg);
495 break;
496 };
497
498 return err;
499 }
500
501 /*
502 * We don't provide read/write/poll interface for user space.
503 */
hci_uart_tty_read(struct tty_struct * tty,struct file * file,unsigned char __user * buf,size_t nr)504 static ssize_t hci_uart_tty_read(struct tty_struct *tty, struct file *file,
505 unsigned char __user *buf, size_t nr)
506 {
507 return 0;
508 }
509
hci_uart_tty_write(struct tty_struct * tty,struct file * file,const unsigned char * data,size_t count)510 static ssize_t hci_uart_tty_write(struct tty_struct *tty, struct file *file,
511 const unsigned char *data, size_t count)
512 {
513 return 0;
514 }
515
hci_uart_tty_poll(struct tty_struct * tty,struct file * filp,poll_table * wait)516 static unsigned int hci_uart_tty_poll(struct tty_struct *tty,
517 struct file *filp, poll_table *wait)
518 {
519 return 0;
520 }
521
hci_uart_init(void)522 static int __init hci_uart_init(void)
523 {
524 static struct tty_ldisc_ops hci_uart_ldisc;
525 int err;
526
527 BT_INFO("HCI UART driver ver %s", VERSION);
528
529 /* Register the tty discipline */
530
531 memset(&hci_uart_ldisc, 0, sizeof (hci_uart_ldisc));
532 hci_uart_ldisc.magic = TTY_LDISC_MAGIC;
533 hci_uart_ldisc.name = "n_hci";
534 hci_uart_ldisc.open = hci_uart_tty_open;
535 hci_uart_ldisc.close = hci_uart_tty_close;
536 hci_uart_ldisc.read = hci_uart_tty_read;
537 hci_uart_ldisc.write = hci_uart_tty_write;
538 hci_uart_ldisc.ioctl = hci_uart_tty_ioctl;
539 hci_uart_ldisc.poll = hci_uart_tty_poll;
540 hci_uart_ldisc.receive_buf = hci_uart_tty_receive;
541 hci_uart_ldisc.write_wakeup = hci_uart_tty_wakeup;
542 hci_uart_ldisc.owner = THIS_MODULE;
543
544 if ((err = tty_register_ldisc(N_HCI, &hci_uart_ldisc))) {
545 BT_ERR("HCI line discipline registration failed. (%d)", err);
546 return err;
547 }
548
549 #ifdef CONFIG_BT_HCIUART_H4
550 h4_init();
551 #endif
552 #ifdef CONFIG_BT_HCIUART_BCSP
553 bcsp_init();
554 #endif
555 #ifdef CONFIG_BT_HCIUART_LL
556 ll_init();
557 #endif
558 #ifdef CONFIG_BT_HCIUART_ATH3K
559 ath_init();
560 #endif
561
562 return 0;
563 }
564
hci_uart_exit(void)565 static void __exit hci_uart_exit(void)
566 {
567 int err;
568
569 #ifdef CONFIG_BT_HCIUART_H4
570 h4_deinit();
571 #endif
572 #ifdef CONFIG_BT_HCIUART_BCSP
573 bcsp_deinit();
574 #endif
575 #ifdef CONFIG_BT_HCIUART_LL
576 ll_deinit();
577 #endif
578 #ifdef CONFIG_BT_HCIUART_ATH3K
579 ath_deinit();
580 #endif
581
582 /* Release tty registration of line discipline */
583 if ((err = tty_unregister_ldisc(N_HCI)))
584 BT_ERR("Can't unregister HCI line discipline (%d)", err);
585 }
586
587 module_init(hci_uart_init);
588 module_exit(hci_uart_exit);
589
590 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
591 MODULE_DESCRIPTION("Bluetooth HCI UART driver ver " VERSION);
592 MODULE_VERSION(VERSION);
593 MODULE_LICENSE("GPL");
594 MODULE_ALIAS_LDISC(N_HCI);
595