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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
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
51static int reset = 0;
52
53static struct hci_uart_proto *hup[HCI_UART_MAX_PROTO];
54
55int hci_uart_register_proto(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 return 0;
66}
67
68int hci_uart_unregister_proto(struct hci_uart_proto *p)
69{
70 if (p->id >= HCI_UART_MAX_PROTO)
71 return -EINVAL;
72
73 if (!hup[p->id])
74 return -EINVAL;
75
76 hup[p->id] = NULL;
77
78 return 0;
79}
80
81static struct hci_uart_proto *hci_uart_get_proto(unsigned int id)
82{
83 if (id >= HCI_UART_MAX_PROTO)
84 return NULL;
85
86 return hup[id];
87}
88
89static inline void hci_uart_tx_complete(struct hci_uart *hu, int pkt_type)
90{
91 struct hci_dev *hdev = hu->hdev;
92
93 /* Update HCI stat counters */
94 switch (pkt_type) {
95 case HCI_COMMAND_PKT:
96 hdev->stat.cmd_tx++;
97 break;
98
99 case HCI_ACLDATA_PKT:
100 hdev->stat.acl_tx++;
101 break;
102
103 case HCI_SCODATA_PKT:
104 hdev->stat.sco_tx++;
105 break;
106 }
107}
108
109static inline struct sk_buff *hci_uart_dequeue(struct hci_uart *hu)
110{
111 struct sk_buff *skb = hu->tx_skb;
112
113 if (!skb)
114 skb = hu->proto->dequeue(hu);
115 else
116 hu->tx_skb = NULL;
117
118 return skb;
119}
120
121int hci_uart_tx_wakeup(struct hci_uart *hu)
122{
123 struct tty_struct *tty = hu->tty;
124 struct hci_dev *hdev = hu->hdev;
125 struct sk_buff *skb;
126
127 if (test_and_set_bit(HCI_UART_SENDING, &hu->tx_state)) {
128 set_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
129 return 0;
130 }
131
132 BT_DBG("");
133
134restart:
135 clear_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
136
137 while ((skb = hci_uart_dequeue(hu))) {
138 int len;
139
140 set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
141 len = tty->ops->write(tty, skb->data, skb->len);
142 hdev->stat.byte_tx += len;
143
144 skb_pull(skb, len);
145 if (skb->len) {
146 hu->tx_skb = skb;
147 break;
148 }
149
150 hci_uart_tx_complete(hu, bt_cb(skb)->pkt_type);
151 kfree_skb(skb);
152 }
153
154 if (test_bit(HCI_UART_TX_WAKEUP, &hu->tx_state))
155 goto restart;
156
157 clear_bit(HCI_UART_SENDING, &hu->tx_state);
158 return 0;
159}
160
161/* ------- Interface to HCI layer ------ */
162/* Initialize device */
163static int hci_uart_open(struct hci_dev *hdev)
164{
165 BT_DBG("%s %p", hdev->name, hdev);
166
167 /* Nothing to do for UART driver */
168
169 set_bit(HCI_RUNNING, &hdev->flags);
170
171 return 0;
172}
173
174/* Reset device */
175static int hci_uart_flush(struct hci_dev *hdev)
176{
177 struct hci_uart *hu = (struct hci_uart *) hdev->driver_data;
178 struct tty_struct *tty = hu->tty;
179
180 BT_DBG("hdev %p tty %p", hdev, tty);
181
182 if (hu->tx_skb) {
183 kfree_skb(hu->tx_skb); hu->tx_skb = NULL;
184 }
185
186 /* Flush any pending characters in the driver and discipline. */
187 tty_ldisc_flush(tty);
188 tty_driver_flush_buffer(tty);
189
190 if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
191 hu->proto->flush(hu);
192
193 return 0;
194}
195
196/* Close device */
197static int hci_uart_close(struct hci_dev *hdev)
198{
199 BT_DBG("hdev %p", hdev);
200
201 if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags))
202 return 0;
203
204 hci_uart_flush(hdev);
205 hdev->flush = NULL;
206 return 0;
207}
208
209/* Send frames from HCI layer */
210static int hci_uart_send_frame(struct sk_buff *skb)
211{
212 struct hci_dev* hdev = (struct hci_dev *) skb->dev;
213 struct hci_uart *hu;
214
215 if (!hdev) {
216 BT_ERR("Frame for unknown device (hdev=NULL)");
217 return -ENODEV;
218 }
219
220 if (!test_bit(HCI_RUNNING, &hdev->flags))
221 return -EBUSY;
222
223 hu = (struct hci_uart *) hdev->driver_data;
224
225 BT_DBG("%s: type %d len %d", hdev->name, bt_cb(skb)->pkt_type, skb->len);
226
227 hu->proto->enqueue(hu, skb);
228
229 hci_uart_tx_wakeup(hu);
230
231 return 0;
232}
233
234static void hci_uart_destruct(struct hci_dev *hdev)
235{
236 if (!hdev)
237 return;
238
239 BT_DBG("%s", hdev->name);
240 kfree(hdev->driver_data);
241}
242
243/* ------ LDISC part ------ */
244/* hci_uart_tty_open
245 *
246 * Called when line discipline changed to HCI_UART.
247 *
248 * Arguments:
249 * tty pointer to tty info structure
250 * Return Value:
251 * 0 if success, otherwise error code
252 */
253static int hci_uart_tty_open(struct tty_struct *tty)
254{
255 struct hci_uart *hu = (void *) tty->disc_data;
256
257 BT_DBG("tty %p", tty);
258
259 /* FIXME: This btw is bogus, nothing requires the old ldisc to clear
260 the pointer */
261 if (hu)
262 return -EEXIST;
263
264 /* Error if the tty has no write op instead of leaving an exploitable
265 hole */
266 if (tty->ops->write == NULL)
267 return -EOPNOTSUPP;
268
269 if (!(hu = kzalloc(sizeof(struct hci_uart), GFP_KERNEL))) {
270 BT_ERR("Can't allocate control structure");
271 return -ENFILE;
272 }
273
274 tty->disc_data = hu;
275 hu->tty = tty;
276 tty->receive_room = 65536;
277
278 spin_lock_init(&hu->rx_lock);
279
280 /* Flush any pending characters in the driver and line discipline. */
281
282 /* FIXME: why is this needed. Note don't use ldisc_ref here as the
283 open path is before the ldisc is referencable */
284
285 if (tty->ldisc->ops->flush_buffer)
286 tty->ldisc->ops->flush_buffer(tty);
287 tty_driver_flush_buffer(tty);
288
289 return 0;
290}
291
292/* hci_uart_tty_close()
293 *
294 * Called when the line discipline is changed to something
295 * else, the tty is closed, or the tty detects a hangup.
296 */
297static void hci_uart_tty_close(struct tty_struct *tty)
298{
299 struct hci_uart *hu = (void *)tty->disc_data;
300
301 BT_DBG("tty %p", tty);
302
303 /* Detach from the tty */
304 tty->disc_data = NULL;
305
306 if (hu) {
307 struct hci_dev *hdev = hu->hdev;
308
309 if (hdev)
310 hci_uart_close(hdev);
311
312 if (test_and_clear_bit(HCI_UART_PROTO_SET, &hu->flags)) {
313 hu->proto->close(hu);
314 if (hdev) {
315 hci_unregister_dev(hdev);
316 hci_free_dev(hdev);
317 }
318 }
319 }
320}
321
322/* hci_uart_tty_wakeup()
323 *
324 * Callback for transmit wakeup. Called when low level
325 * device driver can accept more send data.
326 *
327 * Arguments: tty pointer to associated tty instance data
328 * Return Value: None
329 */
330static void hci_uart_tty_wakeup(struct tty_struct *tty)
331{
332 struct hci_uart *hu = (void *)tty->disc_data;
333
334 BT_DBG("");
335
336 if (!hu)
337 return;
338
339 clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
340
341 if (tty != hu->tty)
342 return;
343
344 if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
345 hci_uart_tx_wakeup(hu);
346}
347
348/* hci_uart_tty_receive()
349 *
350 * Called by tty low level driver when receive data is
351 * available.
352 *
353 * Arguments: tty pointer to tty isntance data
354 * data pointer to received data
355 * flags pointer to flags for data
356 * count count of received data in bytes
357 *
358 * Return Value: None
359 */
360static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data, char *flags, int count)
361{
362 struct hci_uart *hu = (void *)tty->disc_data;
363
364 if (!hu || tty != hu->tty)
365 return;
366
367 if (!test_bit(HCI_UART_PROTO_SET, &hu->flags))
368 return;
369
370 spin_lock(&hu->rx_lock);
371 hu->proto->recv(hu, (void *) data, count);
372 hu->hdev->stat.byte_rx += count;
373 spin_unlock(&hu->rx_lock);
374
375 tty_unthrottle(tty);
376}
377
378static int hci_uart_register_dev(struct hci_uart *hu)
379{
380 struct hci_dev *hdev;
381
382 BT_DBG("");
383
384 /* Initialize and register HCI device */
385 hdev = hci_alloc_dev();
386 if (!hdev) {
387 BT_ERR("Can't allocate HCI device");
388 return -ENOMEM;
389 }
390
391 hu->hdev = hdev;
392
393 hdev->bus = HCI_UART;
394 hdev->driver_data = hu;
395
396 hdev->open = hci_uart_open;
397 hdev->close = hci_uart_close;
398 hdev->flush = hci_uart_flush;
399 hdev->send = hci_uart_send_frame;
400 hdev->destruct = hci_uart_destruct;
401 hdev->parent = hu->tty->dev;
402
403 hdev->owner = THIS_MODULE;
404
405 if (!reset)
406 set_bit(HCI_QUIRK_NO_RESET, &hdev->quirks);
407
408 if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags))
409 set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
410
411 if (hci_register_dev(hdev) < 0) {
412 BT_ERR("Can't register HCI device");
413 hci_free_dev(hdev);
414 return -ENODEV;
415 }
416
417 return 0;
418}
419
420static int hci_uart_set_proto(struct hci_uart *hu, int id)
421{
422 struct hci_uart_proto *p;
423 int err;
424
425 p = hci_uart_get_proto(id);
426 if (!p)
427 return -EPROTONOSUPPORT;
428
429 err = p->open(hu);
430 if (err)
431 return err;
432
433 hu->proto = p;
434
435 err = hci_uart_register_dev(hu);
436 if (err) {
437 p->close(hu);
438 return err;
439 }
440
441 return 0;
442}
443
444/* hci_uart_tty_ioctl()
445 *
446 * Process IOCTL system call for the tty device.
447 *
448 * Arguments:
449 *
450 * tty pointer to tty instance data
451 * file pointer to open file object for device
452 * cmd IOCTL command code
453 * arg argument for IOCTL call (cmd dependent)
454 *
455 * Return Value: Command dependent
456 */
457static int hci_uart_tty_ioctl(struct tty_struct *tty, struct file * file,
458 unsigned int cmd, unsigned long arg)
459{
460 struct hci_uart *hu = (void *)tty->disc_data;
461 int err = 0;
462
463 BT_DBG("");
464
465 /* Verify the status of the device */
466 if (!hu)
467 return -EBADF;
468
469 switch (cmd) {
470 case HCIUARTSETPROTO:
471 if (!test_and_set_bit(HCI_UART_PROTO_SET, &hu->flags)) {
472 err = hci_uart_set_proto(hu, arg);
473 if (err) {
474 clear_bit(HCI_UART_PROTO_SET, &hu->flags);
475 return err;
476 }
477 } else
478 return -EBUSY;
479 break;
480
481 case HCIUARTGETPROTO:
482 if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
483 return hu->proto->id;
484 return -EUNATCH;
485
486 case HCIUARTGETDEVICE:
487 if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
488 return hu->hdev->id;
489 return -EUNATCH;
490
491 case HCIUARTSETFLAGS:
492 if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
493 return -EBUSY;
494 hu->hdev_flags = arg;
495 break;
496
497 case HCIUARTGETFLAGS:
498 return hu->hdev_flags;
499
500 default:
501 err = n_tty_ioctl_helper(tty, file, cmd, arg);
502 break;
503 };
504
505 return err;
506}
507
508/*
509 * We don't provide read/write/poll interface for user space.
510 */
511static ssize_t hci_uart_tty_read(struct tty_struct *tty, struct file *file,
512 unsigned char __user *buf, size_t nr)
513{
514 return 0;
515}
516
517static ssize_t hci_uart_tty_write(struct tty_struct *tty, struct file *file,
518 const unsigned char *data, size_t count)
519{
520 return 0;
521}
522
523static unsigned int hci_uart_tty_poll(struct tty_struct *tty,
524 struct file *filp, poll_table *wait)
525{
526 return 0;
527}
528
529static int __init hci_uart_init(void)
530{
531 static struct tty_ldisc_ops hci_uart_ldisc;
532 int err;
533
534 BT_INFO("HCI UART driver ver %s", VERSION);
535
536 /* Register the tty discipline */
537
538 memset(&hci_uart_ldisc, 0, sizeof (hci_uart_ldisc));
539 hci_uart_ldisc.magic = TTY_LDISC_MAGIC;
540 hci_uart_ldisc.name = "n_hci";
541 hci_uart_ldisc.open = hci_uart_tty_open;
542 hci_uart_ldisc.close = hci_uart_tty_close;
543 hci_uart_ldisc.read = hci_uart_tty_read;
544 hci_uart_ldisc.write = hci_uart_tty_write;
545 hci_uart_ldisc.ioctl = hci_uart_tty_ioctl;
546 hci_uart_ldisc.poll = hci_uart_tty_poll;
547 hci_uart_ldisc.receive_buf = hci_uart_tty_receive;
548 hci_uart_ldisc.write_wakeup = hci_uart_tty_wakeup;
549 hci_uart_ldisc.owner = THIS_MODULE;
550
551 if ((err = tty_register_ldisc(N_HCI, &hci_uart_ldisc))) {
552 BT_ERR("HCI line discipline registration failed. (%d)", err);
553 return err;
554 }
555
556#ifdef CONFIG_BT_HCIUART_H4
557 h4_init();
558#endif
559#ifdef CONFIG_BT_HCIUART_BCSP
560 bcsp_init();
561#endif
562#ifdef CONFIG_BT_HCIUART_LL
563 ll_init();
564#endif
565#ifdef CONFIG_BT_HCIUART_ATH3K
566 ath_init();
567#endif
568
569 return 0;
570}
571
572static void __exit hci_uart_exit(void)
573{
574 int err;
575
576#ifdef CONFIG_BT_HCIUART_H4
577 h4_deinit();
578#endif
579#ifdef CONFIG_BT_HCIUART_BCSP
580 bcsp_deinit();
581#endif
582#ifdef CONFIG_BT_HCIUART_LL
583 ll_deinit();
584#endif
585#ifdef CONFIG_BT_HCIUART_ATH3K
586 ath_deinit();
587#endif
588
589 /* Release tty registration of line discipline */
590 if ((err = tty_unregister_ldisc(N_HCI)))
591 BT_ERR("Can't unregister HCI line discipline (%d)", err);
592}
593
594module_init(hci_uart_init);
595module_exit(hci_uart_exit);
596
597module_param(reset, bool, 0644);
598MODULE_PARM_DESC(reset, "Send HCI reset command on initialization");
599
600MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
601MODULE_DESCRIPTION("Bluetooth HCI UART driver ver " VERSION);
602MODULE_VERSION(VERSION);
603MODULE_LICENSE("GPL");
604MODULE_ALIAS_LDISC(N_HCI);
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 skb = hu->proto->dequeue(hu);
107
108 percpu_up_read(&hu->proto_lock);
109 } else {
110 hu->tx_skb = NULL;
111 }
112
113 return skb;
114}
115
116int hci_uart_tx_wakeup(struct hci_uart *hu)
117{
118 /* This may be called in an IRQ context, so we can't sleep. Therefore
119 * we try to acquire the lock only, and if that fails we assume the
120 * tty is being closed because that is the only time the write lock is
121 * acquired. If, however, at some point in the future the write lock
122 * is also acquired in other situations, then this must be revisited.
123 */
124 if (!percpu_down_read_trylock(&hu->proto_lock))
125 return 0;
126
127 if (!test_bit(HCI_UART_PROTO_READY, &hu->flags))
128 goto no_schedule;
129
130 if (test_and_set_bit(HCI_UART_SENDING, &hu->tx_state)) {
131 set_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
132 goto no_schedule;
133 }
134
135 BT_DBG("");
136
137 schedule_work(&hu->write_work);
138
139no_schedule:
140 percpu_up_read(&hu->proto_lock);
141
142 return 0;
143}
144EXPORT_SYMBOL_GPL(hci_uart_tx_wakeup);
145
146static void hci_uart_write_work(struct work_struct *work)
147{
148 struct hci_uart *hu = container_of(work, struct hci_uart, write_work);
149 struct tty_struct *tty = hu->tty;
150 struct hci_dev *hdev = hu->hdev;
151 struct sk_buff *skb;
152
153 /* REVISIT: should we cope with bad skbs or ->write() returning
154 * and error value ?
155 */
156
157restart:
158 clear_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
159
160 while ((skb = hci_uart_dequeue(hu))) {
161 int len;
162
163 set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
164 len = tty->ops->write(tty, skb->data, skb->len);
165 hdev->stat.byte_tx += len;
166
167 skb_pull(skb, len);
168 if (skb->len) {
169 hu->tx_skb = skb;
170 break;
171 }
172
173 hci_uart_tx_complete(hu, hci_skb_pkt_type(skb));
174 kfree_skb(skb);
175 }
176
177 if (test_bit(HCI_UART_TX_WAKEUP, &hu->tx_state))
178 goto restart;
179
180 clear_bit(HCI_UART_SENDING, &hu->tx_state);
181 wake_up_bit(&hu->tx_state, HCI_UART_SENDING);
182}
183
184void hci_uart_init_work(struct work_struct *work)
185{
186 struct hci_uart *hu = container_of(work, struct hci_uart, init_ready);
187 int err;
188 struct hci_dev *hdev;
189
190 if (!test_and_clear_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
191 return;
192
193 err = hci_register_dev(hu->hdev);
194 if (err < 0) {
195 BT_ERR("Can't register HCI device");
196 clear_bit(HCI_UART_PROTO_READY, &hu->flags);
197 hu->proto->close(hu);
198 hdev = hu->hdev;
199 hu->hdev = NULL;
200 hci_free_dev(hdev);
201 return;
202 }
203
204 set_bit(HCI_UART_REGISTERED, &hu->flags);
205}
206
207int hci_uart_init_ready(struct hci_uart *hu)
208{
209 if (!test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
210 return -EALREADY;
211
212 schedule_work(&hu->init_ready);
213
214 return 0;
215}
216
217int hci_uart_wait_until_sent(struct hci_uart *hu)
218{
219 return wait_on_bit_timeout(&hu->tx_state, HCI_UART_SENDING,
220 TASK_INTERRUPTIBLE,
221 msecs_to_jiffies(2000));
222}
223
224/* ------- Interface to HCI layer ------ */
225/* Reset device */
226static int hci_uart_flush(struct hci_dev *hdev)
227{
228 struct hci_uart *hu = hci_get_drvdata(hdev);
229 struct tty_struct *tty = hu->tty;
230
231 BT_DBG("hdev %p tty %p", hdev, tty);
232
233 if (hu->tx_skb) {
234 kfree_skb(hu->tx_skb); hu->tx_skb = NULL;
235 }
236
237 /* Flush any pending characters in the driver and discipline. */
238 tty_ldisc_flush(tty);
239 tty_driver_flush_buffer(tty);
240
241 percpu_down_read(&hu->proto_lock);
242
243 if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
244 hu->proto->flush(hu);
245
246 percpu_up_read(&hu->proto_lock);
247
248 return 0;
249}
250
251/* Initialize device */
252static int hci_uart_open(struct hci_dev *hdev)
253{
254 BT_DBG("%s %p", hdev->name, hdev);
255
256 /* Undo clearing this from hci_uart_close() */
257 hdev->flush = hci_uart_flush;
258
259 return 0;
260}
261
262/* Close device */
263static int hci_uart_close(struct hci_dev *hdev)
264{
265 BT_DBG("hdev %p", hdev);
266
267 hci_uart_flush(hdev);
268 hdev->flush = NULL;
269 return 0;
270}
271
272/* Send frames from HCI layer */
273static int hci_uart_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
274{
275 struct hci_uart *hu = hci_get_drvdata(hdev);
276
277 BT_DBG("%s: type %d len %d", hdev->name, hci_skb_pkt_type(skb),
278 skb->len);
279
280 percpu_down_read(&hu->proto_lock);
281
282 if (!test_bit(HCI_UART_PROTO_READY, &hu->flags)) {
283 percpu_up_read(&hu->proto_lock);
284 return -EUNATCH;
285 }
286
287 hu->proto->enqueue(hu, skb);
288 percpu_up_read(&hu->proto_lock);
289
290 hci_uart_tx_wakeup(hu);
291
292 return 0;
293}
294
295/* Check the underlying device or tty has flow control support */
296bool hci_uart_has_flow_control(struct hci_uart *hu)
297{
298 /* serdev nodes check if the needed operations are present */
299 if (hu->serdev)
300 return true;
301
302 if (hu->tty->driver->ops->tiocmget && hu->tty->driver->ops->tiocmset)
303 return true;
304
305 return false;
306}
307
308/* Flow control or un-flow control the device */
309void hci_uart_set_flow_control(struct hci_uart *hu, bool enable)
310{
311 struct tty_struct *tty = hu->tty;
312 struct ktermios ktermios;
313 int status;
314 unsigned int set = 0;
315 unsigned int clear = 0;
316
317 if (hu->serdev) {
318 serdev_device_set_flow_control(hu->serdev, !enable);
319 serdev_device_set_rts(hu->serdev, !enable);
320 return;
321 }
322
323 if (enable) {
324 /* Disable hardware flow control */
325 ktermios = tty->termios;
326 ktermios.c_cflag &= ~CRTSCTS;
327 status = tty_set_termios(tty, &ktermios);
328 BT_DBG("Disabling hardware flow control: %s",
329 status ? "failed" : "success");
330
331 /* Clear RTS to prevent the device from sending */
332 /* Most UARTs need OUT2 to enable interrupts */
333 status = tty->driver->ops->tiocmget(tty);
334 BT_DBG("Current tiocm 0x%x", status);
335
336 set &= ~(TIOCM_OUT2 | TIOCM_RTS);
337 clear = ~set;
338 set &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
339 TIOCM_OUT2 | TIOCM_LOOP;
340 clear &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
341 TIOCM_OUT2 | TIOCM_LOOP;
342 status = tty->driver->ops->tiocmset(tty, set, clear);
343 BT_DBG("Clearing RTS: %s", status ? "failed" : "success");
344 } else {
345 /* Set RTS to allow the device to send again */
346 status = tty->driver->ops->tiocmget(tty);
347 BT_DBG("Current tiocm 0x%x", status);
348
349 set |= (TIOCM_OUT2 | TIOCM_RTS);
350 clear = ~set;
351 set &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
352 TIOCM_OUT2 | TIOCM_LOOP;
353 clear &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
354 TIOCM_OUT2 | TIOCM_LOOP;
355 status = tty->driver->ops->tiocmset(tty, set, clear);
356 BT_DBG("Setting RTS: %s", status ? "failed" : "success");
357
358 /* Re-enable hardware flow control */
359 ktermios = tty->termios;
360 ktermios.c_cflag |= CRTSCTS;
361 status = tty_set_termios(tty, &ktermios);
362 BT_DBG("Enabling hardware flow control: %s",
363 status ? "failed" : "success");
364 }
365}
366
367void hci_uart_set_speeds(struct hci_uart *hu, unsigned int init_speed,
368 unsigned int oper_speed)
369{
370 hu->init_speed = init_speed;
371 hu->oper_speed = oper_speed;
372}
373
374void hci_uart_set_baudrate(struct hci_uart *hu, unsigned int speed)
375{
376 struct tty_struct *tty = hu->tty;
377 struct ktermios ktermios;
378
379 ktermios = tty->termios;
380 ktermios.c_cflag &= ~CBAUD;
381 tty_termios_encode_baud_rate(&ktermios, speed, speed);
382
383 /* tty_set_termios() return not checked as it is always 0 */
384 tty_set_termios(tty, &ktermios);
385
386 BT_DBG("%s: New tty speeds: %d/%d", hu->hdev->name,
387 tty->termios.c_ispeed, tty->termios.c_ospeed);
388}
389
390static int hci_uart_setup(struct hci_dev *hdev)
391{
392 struct hci_uart *hu = hci_get_drvdata(hdev);
393 struct hci_rp_read_local_version *ver;
394 struct sk_buff *skb;
395 unsigned int speed;
396 int err;
397
398 /* Init speed if any */
399 if (hu->init_speed)
400 speed = hu->init_speed;
401 else if (hu->proto->init_speed)
402 speed = hu->proto->init_speed;
403 else
404 speed = 0;
405
406 if (speed)
407 hci_uart_set_baudrate(hu, speed);
408
409 /* Operational speed if any */
410 if (hu->oper_speed)
411 speed = hu->oper_speed;
412 else if (hu->proto->oper_speed)
413 speed = hu->proto->oper_speed;
414 else
415 speed = 0;
416
417 if (hu->proto->set_baudrate && speed) {
418 err = hu->proto->set_baudrate(hu, speed);
419 if (!err)
420 hci_uart_set_baudrate(hu, speed);
421 }
422
423 if (hu->proto->setup)
424 return hu->proto->setup(hu);
425
426 if (!test_bit(HCI_UART_VND_DETECT, &hu->hdev_flags))
427 return 0;
428
429 skb = __hci_cmd_sync(hdev, HCI_OP_READ_LOCAL_VERSION, 0, NULL,
430 HCI_INIT_TIMEOUT);
431 if (IS_ERR(skb)) {
432 BT_ERR("%s: Reading local version information failed (%ld)",
433 hdev->name, PTR_ERR(skb));
434 return 0;
435 }
436
437 if (skb->len != sizeof(*ver)) {
438 BT_ERR("%s: Event length mismatch for version information",
439 hdev->name);
440 goto done;
441 }
442
443 ver = (struct hci_rp_read_local_version *)skb->data;
444
445 switch (le16_to_cpu(ver->manufacturer)) {
446#ifdef CONFIG_BT_HCIUART_INTEL
447 case 2:
448 hdev->set_bdaddr = btintel_set_bdaddr;
449 btintel_check_bdaddr(hdev);
450 break;
451#endif
452#ifdef CONFIG_BT_HCIUART_BCM
453 case 15:
454 hdev->set_bdaddr = btbcm_set_bdaddr;
455 btbcm_check_bdaddr(hdev);
456 break;
457#endif
458 default:
459 break;
460 }
461
462done:
463 kfree_skb(skb);
464 return 0;
465}
466
467/* ------ LDISC part ------ */
468/* hci_uart_tty_open
469 *
470 * Called when line discipline changed to HCI_UART.
471 *
472 * Arguments:
473 * tty pointer to tty info structure
474 * Return Value:
475 * 0 if success, otherwise error code
476 */
477static int hci_uart_tty_open(struct tty_struct *tty)
478{
479 struct hci_uart *hu;
480
481 BT_DBG("tty %p", tty);
482
483 /* Error if the tty has no write op instead of leaving an exploitable
484 * hole
485 */
486 if (tty->ops->write == NULL)
487 return -EOPNOTSUPP;
488
489 hu = kzalloc(sizeof(struct hci_uart), GFP_KERNEL);
490 if (!hu) {
491 BT_ERR("Can't allocate control structure");
492 return -ENFILE;
493 }
494
495 tty->disc_data = hu;
496 hu->tty = tty;
497 tty->receive_room = 65536;
498
499 /* disable alignment support by default */
500 hu->alignment = 1;
501 hu->padding = 0;
502
503 INIT_WORK(&hu->init_ready, hci_uart_init_work);
504 INIT_WORK(&hu->write_work, hci_uart_write_work);
505
506 percpu_init_rwsem(&hu->proto_lock);
507
508 /* Flush any pending characters in the driver */
509 tty_driver_flush_buffer(tty);
510
511 return 0;
512}
513
514/* hci_uart_tty_close()
515 *
516 * Called when the line discipline is changed to something
517 * else, the tty is closed, or the tty detects a hangup.
518 */
519static void hci_uart_tty_close(struct tty_struct *tty)
520{
521 struct hci_uart *hu = tty->disc_data;
522 struct hci_dev *hdev;
523
524 BT_DBG("tty %p", tty);
525
526 /* Detach from the tty */
527 tty->disc_data = NULL;
528
529 if (!hu)
530 return;
531
532 hdev = hu->hdev;
533 if (hdev)
534 hci_uart_close(hdev);
535
536 if (test_bit(HCI_UART_PROTO_READY, &hu->flags)) {
537 percpu_down_write(&hu->proto_lock);
538 clear_bit(HCI_UART_PROTO_READY, &hu->flags);
539 percpu_up_write(&hu->proto_lock);
540
541 cancel_work_sync(&hu->write_work);
542
543 if (hdev) {
544 if (test_bit(HCI_UART_REGISTERED, &hu->flags))
545 hci_unregister_dev(hdev);
546 hci_free_dev(hdev);
547 }
548 hu->proto->close(hu);
549 }
550 clear_bit(HCI_UART_PROTO_SET, &hu->flags);
551
552 percpu_free_rwsem(&hu->proto_lock);
553
554 kfree(hu);
555}
556
557/* hci_uart_tty_wakeup()
558 *
559 * Callback for transmit wakeup. Called when low level
560 * device driver can accept more send data.
561 *
562 * Arguments: tty pointer to associated tty instance data
563 * Return Value: None
564 */
565static void hci_uart_tty_wakeup(struct tty_struct *tty)
566{
567 struct hci_uart *hu = tty->disc_data;
568
569 BT_DBG("");
570
571 if (!hu)
572 return;
573
574 clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
575
576 if (tty != hu->tty)
577 return;
578
579 if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
580 hci_uart_tx_wakeup(hu);
581}
582
583/* hci_uart_tty_receive()
584 *
585 * Called by tty low level driver when receive data is
586 * available.
587 *
588 * Arguments: tty pointer to tty isntance data
589 * data pointer to received data
590 * flags pointer to flags for data
591 * count count of received data in bytes
592 *
593 * Return Value: None
594 */
595static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data,
596 char *flags, int count)
597{
598 struct hci_uart *hu = tty->disc_data;
599
600 if (!hu || tty != hu->tty)
601 return;
602
603 percpu_down_read(&hu->proto_lock);
604
605 if (!test_bit(HCI_UART_PROTO_READY, &hu->flags)) {
606 percpu_up_read(&hu->proto_lock);
607 return;
608 }
609
610 /* It does not need a lock here as it is already protected by a mutex in
611 * tty caller
612 */
613 hu->proto->recv(hu, data, count);
614 percpu_up_read(&hu->proto_lock);
615
616 if (hu->hdev)
617 hu->hdev->stat.byte_rx += count;
618
619 tty_unthrottle(tty);
620}
621
622static int hci_uart_register_dev(struct hci_uart *hu)
623{
624 struct hci_dev *hdev;
625 int err;
626
627 BT_DBG("");
628
629 /* Initialize and register HCI device */
630 hdev = hci_alloc_dev();
631 if (!hdev) {
632 BT_ERR("Can't allocate HCI device");
633 return -ENOMEM;
634 }
635
636 hu->hdev = hdev;
637
638 hdev->bus = HCI_UART;
639 hci_set_drvdata(hdev, hu);
640
641 /* Only when vendor specific setup callback is provided, consider
642 * the manufacturer information valid. This avoids filling in the
643 * value for Ericsson when nothing is specified.
644 */
645 if (hu->proto->setup)
646 hdev->manufacturer = hu->proto->manufacturer;
647
648 hdev->open = hci_uart_open;
649 hdev->close = hci_uart_close;
650 hdev->flush = hci_uart_flush;
651 hdev->send = hci_uart_send_frame;
652 hdev->setup = hci_uart_setup;
653 SET_HCIDEV_DEV(hdev, hu->tty->dev);
654
655 if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags))
656 set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
657
658 if (test_bit(HCI_UART_EXT_CONFIG, &hu->hdev_flags))
659 set_bit(HCI_QUIRK_EXTERNAL_CONFIG, &hdev->quirks);
660
661 if (!test_bit(HCI_UART_RESET_ON_INIT, &hu->hdev_flags))
662 set_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks);
663
664 if (test_bit(HCI_UART_CREATE_AMP, &hu->hdev_flags))
665 hdev->dev_type = HCI_AMP;
666 else
667 hdev->dev_type = HCI_PRIMARY;
668
669 /* Only call open() for the protocol after hdev is fully initialized as
670 * open() (or a timer/workqueue it starts) may attempt to reference it.
671 */
672 err = hu->proto->open(hu);
673 if (err) {
674 hu->hdev = NULL;
675 hci_free_dev(hdev);
676 return err;
677 }
678
679 if (test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
680 return 0;
681
682 if (hci_register_dev(hdev) < 0) {
683 BT_ERR("Can't register HCI device");
684 hu->proto->close(hu);
685 hu->hdev = NULL;
686 hci_free_dev(hdev);
687 return -ENODEV;
688 }
689
690 set_bit(HCI_UART_REGISTERED, &hu->flags);
691
692 return 0;
693}
694
695static int hci_uart_set_proto(struct hci_uart *hu, int id)
696{
697 const struct hci_uart_proto *p;
698 int err;
699
700 p = hci_uart_get_proto(id);
701 if (!p)
702 return -EPROTONOSUPPORT;
703
704 hu->proto = p;
705
706 err = hci_uart_register_dev(hu);
707 if (err) {
708 return err;
709 }
710
711 set_bit(HCI_UART_PROTO_READY, &hu->flags);
712 return 0;
713}
714
715static int hci_uart_set_flags(struct hci_uart *hu, unsigned long flags)
716{
717 unsigned long valid_flags = BIT(HCI_UART_RAW_DEVICE) |
718 BIT(HCI_UART_RESET_ON_INIT) |
719 BIT(HCI_UART_CREATE_AMP) |
720 BIT(HCI_UART_INIT_PENDING) |
721 BIT(HCI_UART_EXT_CONFIG) |
722 BIT(HCI_UART_VND_DETECT);
723
724 if (flags & ~valid_flags)
725 return -EINVAL;
726
727 hu->hdev_flags = flags;
728
729 return 0;
730}
731
732/* hci_uart_tty_ioctl()
733 *
734 * Process IOCTL system call for the tty device.
735 *
736 * Arguments:
737 *
738 * tty pointer to tty instance data
739 * file pointer to open file object for device
740 * cmd IOCTL command code
741 * arg argument for IOCTL call (cmd dependent)
742 *
743 * Return Value: Command dependent
744 */
745static int hci_uart_tty_ioctl(struct tty_struct *tty, struct file *file,
746 unsigned int cmd, unsigned long arg)
747{
748 struct hci_uart *hu = tty->disc_data;
749 int err = 0;
750
751 BT_DBG("");
752
753 /* Verify the status of the device */
754 if (!hu)
755 return -EBADF;
756
757 switch (cmd) {
758 case HCIUARTSETPROTO:
759 if (!test_and_set_bit(HCI_UART_PROTO_SET, &hu->flags)) {
760 err = hci_uart_set_proto(hu, arg);
761 if (err)
762 clear_bit(HCI_UART_PROTO_SET, &hu->flags);
763 } else
764 err = -EBUSY;
765 break;
766
767 case HCIUARTGETPROTO:
768 if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
769 err = hu->proto->id;
770 else
771 err = -EUNATCH;
772 break;
773
774 case HCIUARTGETDEVICE:
775 if (test_bit(HCI_UART_REGISTERED, &hu->flags))
776 err = hu->hdev->id;
777 else
778 err = -EUNATCH;
779 break;
780
781 case HCIUARTSETFLAGS:
782 if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
783 err = -EBUSY;
784 else
785 err = hci_uart_set_flags(hu, arg);
786 break;
787
788 case HCIUARTGETFLAGS:
789 err = hu->hdev_flags;
790 break;
791
792 default:
793 err = n_tty_ioctl_helper(tty, file, cmd, arg);
794 break;
795 }
796
797 return err;
798}
799
800/*
801 * We don't provide read/write/poll interface for user space.
802 */
803static ssize_t hci_uart_tty_read(struct tty_struct *tty, struct file *file,
804 unsigned char __user *buf, size_t nr)
805{
806 return 0;
807}
808
809static ssize_t hci_uart_tty_write(struct tty_struct *tty, struct file *file,
810 const unsigned char *data, size_t count)
811{
812 return 0;
813}
814
815static __poll_t hci_uart_tty_poll(struct tty_struct *tty,
816 struct file *filp, poll_table *wait)
817{
818 return 0;
819}
820
821static int __init hci_uart_init(void)
822{
823 static struct tty_ldisc_ops hci_uart_ldisc;
824 int err;
825
826 BT_INFO("HCI UART driver ver %s", VERSION);
827
828 /* Register the tty discipline */
829
830 memset(&hci_uart_ldisc, 0, sizeof(hci_uart_ldisc));
831 hci_uart_ldisc.magic = TTY_LDISC_MAGIC;
832 hci_uart_ldisc.name = "n_hci";
833 hci_uart_ldisc.open = hci_uart_tty_open;
834 hci_uart_ldisc.close = hci_uart_tty_close;
835 hci_uart_ldisc.read = hci_uart_tty_read;
836 hci_uart_ldisc.write = hci_uart_tty_write;
837 hci_uart_ldisc.ioctl = hci_uart_tty_ioctl;
838 hci_uart_ldisc.compat_ioctl = hci_uart_tty_ioctl;
839 hci_uart_ldisc.poll = hci_uart_tty_poll;
840 hci_uart_ldisc.receive_buf = hci_uart_tty_receive;
841 hci_uart_ldisc.write_wakeup = hci_uart_tty_wakeup;
842 hci_uart_ldisc.owner = THIS_MODULE;
843
844 err = tty_register_ldisc(N_HCI, &hci_uart_ldisc);
845 if (err) {
846 BT_ERR("HCI line discipline registration failed. (%d)", err);
847 return err;
848 }
849
850#ifdef CONFIG_BT_HCIUART_H4
851 h4_init();
852#endif
853#ifdef CONFIG_BT_HCIUART_BCSP
854 bcsp_init();
855#endif
856#ifdef CONFIG_BT_HCIUART_LL
857 ll_init();
858#endif
859#ifdef CONFIG_BT_HCIUART_ATH3K
860 ath_init();
861#endif
862#ifdef CONFIG_BT_HCIUART_3WIRE
863 h5_init();
864#endif
865#ifdef CONFIG_BT_HCIUART_INTEL
866 intel_init();
867#endif
868#ifdef CONFIG_BT_HCIUART_BCM
869 bcm_init();
870#endif
871#ifdef CONFIG_BT_HCIUART_QCA
872 qca_init();
873#endif
874#ifdef CONFIG_BT_HCIUART_AG6XX
875 ag6xx_init();
876#endif
877#ifdef CONFIG_BT_HCIUART_MRVL
878 mrvl_init();
879#endif
880
881 return 0;
882}
883
884static void __exit hci_uart_exit(void)
885{
886 int err;
887
888#ifdef CONFIG_BT_HCIUART_H4
889 h4_deinit();
890#endif
891#ifdef CONFIG_BT_HCIUART_BCSP
892 bcsp_deinit();
893#endif
894#ifdef CONFIG_BT_HCIUART_LL
895 ll_deinit();
896#endif
897#ifdef CONFIG_BT_HCIUART_ATH3K
898 ath_deinit();
899#endif
900#ifdef CONFIG_BT_HCIUART_3WIRE
901 h5_deinit();
902#endif
903#ifdef CONFIG_BT_HCIUART_INTEL
904 intel_deinit();
905#endif
906#ifdef CONFIG_BT_HCIUART_BCM
907 bcm_deinit();
908#endif
909#ifdef CONFIG_BT_HCIUART_QCA
910 qca_deinit();
911#endif
912#ifdef CONFIG_BT_HCIUART_AG6XX
913 ag6xx_deinit();
914#endif
915#ifdef CONFIG_BT_HCIUART_MRVL
916 mrvl_deinit();
917#endif
918
919 /* Release tty registration of line discipline */
920 err = tty_unregister_ldisc(N_HCI);
921 if (err)
922 BT_ERR("Can't unregister HCI line discipline (%d)", err);
923}
924
925module_init(hci_uart_init);
926module_exit(hci_uart_exit);
927
928MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
929MODULE_DESCRIPTION("Bluetooth HCI UART driver ver " VERSION);
930MODULE_VERSION(VERSION);
931MODULE_LICENSE("GPL");
932MODULE_ALIAS_LDISC(N_HCI);