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Merge tag 'fbdev-3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/tomba/linux
[deliverable/linux.git] / drivers / bluetooth / hci_h5.c
1 /*
2 *
3 * Bluetooth HCI Three-wire UART driver
4 *
5 * Copyright (C) 2012 Intel Corporation
6 *
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 *
22 */
23
24 #include <linux/kernel.h>
25 #include <linux/errno.h>
26 #include <linux/skbuff.h>
27
28 #include <net/bluetooth/bluetooth.h>
29 #include <net/bluetooth/hci_core.h>
30
31 #include "hci_uart.h"
32
33 #define HCI_3WIRE_ACK_PKT 0
34 #define HCI_3WIRE_LINK_PKT 15
35
36 /* Sliding window size */
37 #define H5_TX_WIN_MAX 4
38
39 #define H5_ACK_TIMEOUT msecs_to_jiffies(250)
40 #define H5_SYNC_TIMEOUT msecs_to_jiffies(100)
41
42 /*
43 * Maximum Three-wire packet:
44 * 4 byte header + max value for 12-bit length + 2 bytes for CRC
45 */
46 #define H5_MAX_LEN (4 + 0xfff + 2)
47
48 /* Convenience macros for reading Three-wire header values */
49 #define H5_HDR_SEQ(hdr) ((hdr)[0] & 0x07)
50 #define H5_HDR_ACK(hdr) (((hdr)[0] >> 3) & 0x07)
51 #define H5_HDR_CRC(hdr) (((hdr)[0] >> 6) & 0x01)
52 #define H5_HDR_RELIABLE(hdr) (((hdr)[0] >> 7) & 0x01)
53 #define H5_HDR_PKT_TYPE(hdr) ((hdr)[1] & 0x0f)
54 #define H5_HDR_LEN(hdr) ((((hdr)[1] >> 4) & 0xff) + ((hdr)[2] << 4))
55
56 #define SLIP_DELIMITER 0xc0
57 #define SLIP_ESC 0xdb
58 #define SLIP_ESC_DELIM 0xdc
59 #define SLIP_ESC_ESC 0xdd
60
61 /* H5 state flags */
62 enum {
63 H5_RX_ESC, /* SLIP escape mode */
64 H5_TX_ACK_REQ, /* Pending ack to send */
65 };
66
67 struct h5 {
68 struct sk_buff_head unack; /* Unack'ed packets queue */
69 struct sk_buff_head rel; /* Reliable packets queue */
70 struct sk_buff_head unrel; /* Unreliable packets queue */
71
72 unsigned long flags;
73
74 struct sk_buff *rx_skb; /* Receive buffer */
75 size_t rx_pending; /* Expecting more bytes */
76 u8 rx_ack; /* Last ack number received */
77
78 int (*rx_func) (struct hci_uart *hu, u8 c);
79
80 struct timer_list timer; /* Retransmission timer */
81
82 u8 tx_seq; /* Next seq number to send */
83 u8 tx_ack; /* Next ack number to send */
84 u8 tx_win; /* Sliding window size */
85
86 enum {
87 H5_UNINITIALIZED,
88 H5_INITIALIZED,
89 H5_ACTIVE,
90 } state;
91
92 enum {
93 H5_AWAKE,
94 H5_SLEEPING,
95 H5_WAKING_UP,
96 } sleep;
97 };
98
99 static void h5_reset_rx(struct h5 *h5);
100
101 static void h5_link_control(struct hci_uart *hu, const void *data, size_t len)
102 {
103 struct h5 *h5 = hu->priv;
104 struct sk_buff *nskb;
105
106 nskb = alloc_skb(3, GFP_ATOMIC);
107 if (!nskb)
108 return;
109
110 bt_cb(nskb)->pkt_type = HCI_3WIRE_LINK_PKT;
111
112 memcpy(skb_put(nskb, len), data, len);
113
114 skb_queue_tail(&h5->unrel, nskb);
115 }
116
117 static u8 h5_cfg_field(struct h5 *h5)
118 {
119 u8 field = 0;
120
121 /* Sliding window size (first 3 bits) */
122 field |= (h5->tx_win & 7);
123
124 return field;
125 }
126
127 static void h5_timed_event(unsigned long arg)
128 {
129 const unsigned char sync_req[] = { 0x01, 0x7e };
130 unsigned char conf_req[] = { 0x03, 0xfc, 0x01 };
131 struct hci_uart *hu = (struct hci_uart *) arg;
132 struct h5 *h5 = hu->priv;
133 struct sk_buff *skb;
134 unsigned long flags;
135
136 BT_DBG("%s", hu->hdev->name);
137
138 if (h5->state == H5_UNINITIALIZED)
139 h5_link_control(hu, sync_req, sizeof(sync_req));
140
141 if (h5->state == H5_INITIALIZED) {
142 conf_req[2] = h5_cfg_field(h5);
143 h5_link_control(hu, conf_req, sizeof(conf_req));
144 }
145
146 if (h5->state != H5_ACTIVE) {
147 mod_timer(&h5->timer, jiffies + H5_SYNC_TIMEOUT);
148 goto wakeup;
149 }
150
151 if (h5->sleep != H5_AWAKE) {
152 h5->sleep = H5_SLEEPING;
153 goto wakeup;
154 }
155
156 BT_DBG("hu %p retransmitting %u pkts", hu, h5->unack.qlen);
157
158 spin_lock_irqsave_nested(&h5->unack.lock, flags, SINGLE_DEPTH_NESTING);
159
160 while ((skb = __skb_dequeue_tail(&h5->unack)) != NULL) {
161 h5->tx_seq = (h5->tx_seq - 1) & 0x07;
162 skb_queue_head(&h5->rel, skb);
163 }
164
165 spin_unlock_irqrestore(&h5->unack.lock, flags);
166
167 wakeup:
168 hci_uart_tx_wakeup(hu);
169 }
170
171 static int h5_open(struct hci_uart *hu)
172 {
173 struct h5 *h5;
174 const unsigned char sync[] = { 0x01, 0x7e };
175
176 BT_DBG("hu %p", hu);
177
178 h5 = kzalloc(sizeof(*h5), GFP_KERNEL);
179 if (!h5)
180 return -ENOMEM;
181
182 hu->priv = h5;
183
184 skb_queue_head_init(&h5->unack);
185 skb_queue_head_init(&h5->rel);
186 skb_queue_head_init(&h5->unrel);
187
188 h5_reset_rx(h5);
189
190 init_timer(&h5->timer);
191 h5->timer.function = h5_timed_event;
192 h5->timer.data = (unsigned long) hu;
193
194 h5->tx_win = H5_TX_WIN_MAX;
195
196 set_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags);
197
198 /* Send initial sync request */
199 h5_link_control(hu, sync, sizeof(sync));
200 mod_timer(&h5->timer, jiffies + H5_SYNC_TIMEOUT);
201
202 return 0;
203 }
204
205 static int h5_close(struct hci_uart *hu)
206 {
207 struct h5 *h5 = hu->priv;
208
209 del_timer_sync(&h5->timer);
210
211 skb_queue_purge(&h5->unack);
212 skb_queue_purge(&h5->rel);
213 skb_queue_purge(&h5->unrel);
214
215 kfree(h5);
216
217 return 0;
218 }
219
220 static void h5_pkt_cull(struct h5 *h5)
221 {
222 struct sk_buff *skb, *tmp;
223 unsigned long flags;
224 int i, to_remove;
225 u8 seq;
226
227 spin_lock_irqsave(&h5->unack.lock, flags);
228
229 to_remove = skb_queue_len(&h5->unack);
230 if (to_remove == 0)
231 goto unlock;
232
233 seq = h5->tx_seq;
234
235 while (to_remove > 0) {
236 if (h5->rx_ack == seq)
237 break;
238
239 to_remove--;
240 seq = (seq - 1) & 0x07;
241 }
242
243 if (seq != h5->rx_ack)
244 BT_ERR("Controller acked invalid packet");
245
246 i = 0;
247 skb_queue_walk_safe(&h5->unack, skb, tmp) {
248 if (i++ >= to_remove)
249 break;
250
251 __skb_unlink(skb, &h5->unack);
252 kfree_skb(skb);
253 }
254
255 if (skb_queue_empty(&h5->unack))
256 del_timer(&h5->timer);
257
258 unlock:
259 spin_unlock_irqrestore(&h5->unack.lock, flags);
260 }
261
262 static void h5_handle_internal_rx(struct hci_uart *hu)
263 {
264 struct h5 *h5 = hu->priv;
265 const unsigned char sync_req[] = { 0x01, 0x7e };
266 const unsigned char sync_rsp[] = { 0x02, 0x7d };
267 unsigned char conf_req[] = { 0x03, 0xfc, 0x01 };
268 const unsigned char conf_rsp[] = { 0x04, 0x7b };
269 const unsigned char wakeup_req[] = { 0x05, 0xfa };
270 const unsigned char woken_req[] = { 0x06, 0xf9 };
271 const unsigned char sleep_req[] = { 0x07, 0x78 };
272 const unsigned char *hdr = h5->rx_skb->data;
273 const unsigned char *data = &h5->rx_skb->data[4];
274
275 BT_DBG("%s", hu->hdev->name);
276
277 if (H5_HDR_PKT_TYPE(hdr) != HCI_3WIRE_LINK_PKT)
278 return;
279
280 if (H5_HDR_LEN(hdr) < 2)
281 return;
282
283 conf_req[2] = h5_cfg_field(h5);
284
285 if (memcmp(data, sync_req, 2) == 0) {
286 h5_link_control(hu, sync_rsp, 2);
287 } else if (memcmp(data, sync_rsp, 2) == 0) {
288 h5->state = H5_INITIALIZED;
289 h5_link_control(hu, conf_req, 3);
290 } else if (memcmp(data, conf_req, 2) == 0) {
291 h5_link_control(hu, conf_rsp, 2);
292 h5_link_control(hu, conf_req, 3);
293 } else if (memcmp(data, conf_rsp, 2) == 0) {
294 if (H5_HDR_LEN(hdr) > 2)
295 h5->tx_win = (data[2] & 7);
296 BT_DBG("Three-wire init complete. tx_win %u", h5->tx_win);
297 h5->state = H5_ACTIVE;
298 hci_uart_init_ready(hu);
299 return;
300 } else if (memcmp(data, sleep_req, 2) == 0) {
301 BT_DBG("Peer went to sleep");
302 h5->sleep = H5_SLEEPING;
303 return;
304 } else if (memcmp(data, woken_req, 2) == 0) {
305 BT_DBG("Peer woke up");
306 h5->sleep = H5_AWAKE;
307 } else if (memcmp(data, wakeup_req, 2) == 0) {
308 BT_DBG("Peer requested wakeup");
309 h5_link_control(hu, woken_req, 2);
310 h5->sleep = H5_AWAKE;
311 } else {
312 BT_DBG("Link Control: 0x%02hhx 0x%02hhx", data[0], data[1]);
313 return;
314 }
315
316 hci_uart_tx_wakeup(hu);
317 }
318
319 static void h5_complete_rx_pkt(struct hci_uart *hu)
320 {
321 struct h5 *h5 = hu->priv;
322 const unsigned char *hdr = h5->rx_skb->data;
323
324 if (H5_HDR_RELIABLE(hdr)) {
325 h5->tx_ack = (h5->tx_ack + 1) % 8;
326 set_bit(H5_TX_ACK_REQ, &h5->flags);
327 hci_uart_tx_wakeup(hu);
328 }
329
330 h5->rx_ack = H5_HDR_ACK(hdr);
331
332 h5_pkt_cull(h5);
333
334 switch (H5_HDR_PKT_TYPE(hdr)) {
335 case HCI_EVENT_PKT:
336 case HCI_ACLDATA_PKT:
337 case HCI_SCODATA_PKT:
338 bt_cb(h5->rx_skb)->pkt_type = H5_HDR_PKT_TYPE(hdr);
339
340 /* Remove Three-wire header */
341 skb_pull(h5->rx_skb, 4);
342
343 hci_recv_frame(hu->hdev, h5->rx_skb);
344 h5->rx_skb = NULL;
345
346 break;
347
348 default:
349 h5_handle_internal_rx(hu);
350 break;
351 }
352
353 h5_reset_rx(h5);
354 }
355
356 static int h5_rx_crc(struct hci_uart *hu, unsigned char c)
357 {
358 h5_complete_rx_pkt(hu);
359
360 return 0;
361 }
362
363 static int h5_rx_payload(struct hci_uart *hu, unsigned char c)
364 {
365 struct h5 *h5 = hu->priv;
366 const unsigned char *hdr = h5->rx_skb->data;
367
368 if (H5_HDR_CRC(hdr)) {
369 h5->rx_func = h5_rx_crc;
370 h5->rx_pending = 2;
371 } else {
372 h5_complete_rx_pkt(hu);
373 }
374
375 return 0;
376 }
377
378 static int h5_rx_3wire_hdr(struct hci_uart *hu, unsigned char c)
379 {
380 struct h5 *h5 = hu->priv;
381 const unsigned char *hdr = h5->rx_skb->data;
382
383 BT_DBG("%s rx: seq %u ack %u crc %u rel %u type %u len %u",
384 hu->hdev->name, H5_HDR_SEQ(hdr), H5_HDR_ACK(hdr),
385 H5_HDR_CRC(hdr), H5_HDR_RELIABLE(hdr), H5_HDR_PKT_TYPE(hdr),
386 H5_HDR_LEN(hdr));
387
388 if (((hdr[0] + hdr[1] + hdr[2] + hdr[3]) & 0xff) != 0xff) {
389 BT_ERR("Invalid header checksum");
390 h5_reset_rx(h5);
391 return 0;
392 }
393
394 if (H5_HDR_RELIABLE(hdr) && H5_HDR_SEQ(hdr) != h5->tx_ack) {
395 BT_ERR("Out-of-order packet arrived (%u != %u)",
396 H5_HDR_SEQ(hdr), h5->tx_ack);
397 h5_reset_rx(h5);
398 return 0;
399 }
400
401 if (h5->state != H5_ACTIVE &&
402 H5_HDR_PKT_TYPE(hdr) != HCI_3WIRE_LINK_PKT) {
403 BT_ERR("Non-link packet received in non-active state");
404 h5_reset_rx(h5);
405 return 0;
406 }
407
408 h5->rx_func = h5_rx_payload;
409 h5->rx_pending = H5_HDR_LEN(hdr);
410
411 return 0;
412 }
413
414 static int h5_rx_pkt_start(struct hci_uart *hu, unsigned char c)
415 {
416 struct h5 *h5 = hu->priv;
417
418 if (c == SLIP_DELIMITER)
419 return 1;
420
421 h5->rx_func = h5_rx_3wire_hdr;
422 h5->rx_pending = 4;
423
424 h5->rx_skb = bt_skb_alloc(H5_MAX_LEN, GFP_ATOMIC);
425 if (!h5->rx_skb) {
426 BT_ERR("Can't allocate mem for new packet");
427 h5_reset_rx(h5);
428 return -ENOMEM;
429 }
430
431 h5->rx_skb->dev = (void *) hu->hdev;
432
433 return 0;
434 }
435
436 static int h5_rx_delimiter(struct hci_uart *hu, unsigned char c)
437 {
438 struct h5 *h5 = hu->priv;
439
440 if (c == SLIP_DELIMITER)
441 h5->rx_func = h5_rx_pkt_start;
442
443 return 1;
444 }
445
446 static void h5_unslip_one_byte(struct h5 *h5, unsigned char c)
447 {
448 const u8 delim = SLIP_DELIMITER, esc = SLIP_ESC;
449 const u8 *byte = &c;
450
451 if (!test_bit(H5_RX_ESC, &h5->flags) && c == SLIP_ESC) {
452 set_bit(H5_RX_ESC, &h5->flags);
453 return;
454 }
455
456 if (test_and_clear_bit(H5_RX_ESC, &h5->flags)) {
457 switch (c) {
458 case SLIP_ESC_DELIM:
459 byte = &delim;
460 break;
461 case SLIP_ESC_ESC:
462 byte = &esc;
463 break;
464 default:
465 BT_ERR("Invalid esc byte 0x%02hhx", c);
466 h5_reset_rx(h5);
467 return;
468 }
469 }
470
471 memcpy(skb_put(h5->rx_skb, 1), byte, 1);
472 h5->rx_pending--;
473
474 BT_DBG("unsliped 0x%02hhx, rx_pending %zu", *byte, h5->rx_pending);
475 }
476
477 static void h5_reset_rx(struct h5 *h5)
478 {
479 if (h5->rx_skb) {
480 kfree_skb(h5->rx_skb);
481 h5->rx_skb = NULL;
482 }
483
484 h5->rx_func = h5_rx_delimiter;
485 h5->rx_pending = 0;
486 clear_bit(H5_RX_ESC, &h5->flags);
487 }
488
489 static int h5_recv(struct hci_uart *hu, void *data, int count)
490 {
491 struct h5 *h5 = hu->priv;
492 unsigned char *ptr = data;
493
494 BT_DBG("%s pending %zu count %d", hu->hdev->name, h5->rx_pending,
495 count);
496
497 while (count > 0) {
498 int processed;
499
500 if (h5->rx_pending > 0) {
501 if (*ptr == SLIP_DELIMITER) {
502 BT_ERR("Too short H5 packet");
503 h5_reset_rx(h5);
504 continue;
505 }
506
507 h5_unslip_one_byte(h5, *ptr);
508
509 ptr++; count--;
510 continue;
511 }
512
513 processed = h5->rx_func(hu, *ptr);
514 if (processed < 0)
515 return processed;
516
517 ptr += processed;
518 count -= processed;
519 }
520
521 return 0;
522 }
523
524 static int h5_enqueue(struct hci_uart *hu, struct sk_buff *skb)
525 {
526 struct h5 *h5 = hu->priv;
527
528 if (skb->len > 0xfff) {
529 BT_ERR("Packet too long (%u bytes)", skb->len);
530 kfree_skb(skb);
531 return 0;
532 }
533
534 if (h5->state != H5_ACTIVE) {
535 BT_ERR("Ignoring HCI data in non-active state");
536 kfree_skb(skb);
537 return 0;
538 }
539
540 switch (bt_cb(skb)->pkt_type) {
541 case HCI_ACLDATA_PKT:
542 case HCI_COMMAND_PKT:
543 skb_queue_tail(&h5->rel, skb);
544 break;
545
546 case HCI_SCODATA_PKT:
547 skb_queue_tail(&h5->unrel, skb);
548 break;
549
550 default:
551 BT_ERR("Unknown packet type %u", bt_cb(skb)->pkt_type);
552 kfree_skb(skb);
553 break;
554 }
555
556 return 0;
557 }
558
559 static void h5_slip_delim(struct sk_buff *skb)
560 {
561 const char delim = SLIP_DELIMITER;
562
563 memcpy(skb_put(skb, 1), &delim, 1);
564 }
565
566 static void h5_slip_one_byte(struct sk_buff *skb, u8 c)
567 {
568 const char esc_delim[2] = { SLIP_ESC, SLIP_ESC_DELIM };
569 const char esc_esc[2] = { SLIP_ESC, SLIP_ESC_ESC };
570
571 switch (c) {
572 case SLIP_DELIMITER:
573 memcpy(skb_put(skb, 2), &esc_delim, 2);
574 break;
575 case SLIP_ESC:
576 memcpy(skb_put(skb, 2), &esc_esc, 2);
577 break;
578 default:
579 memcpy(skb_put(skb, 1), &c, 1);
580 }
581 }
582
583 static bool valid_packet_type(u8 type)
584 {
585 switch (type) {
586 case HCI_ACLDATA_PKT:
587 case HCI_COMMAND_PKT:
588 case HCI_SCODATA_PKT:
589 case HCI_3WIRE_LINK_PKT:
590 case HCI_3WIRE_ACK_PKT:
591 return true;
592 default:
593 return false;
594 }
595 }
596
597 static struct sk_buff *h5_prepare_pkt(struct hci_uart *hu, u8 pkt_type,
598 const u8 *data, size_t len)
599 {
600 struct h5 *h5 = hu->priv;
601 struct sk_buff *nskb;
602 u8 hdr[4];
603 int i;
604
605 if (!valid_packet_type(pkt_type)) {
606 BT_ERR("Unknown packet type %u", pkt_type);
607 return NULL;
608 }
609
610 /*
611 * Max len of packet: (original len + 4 (H5 hdr) + 2 (crc)) * 2
612 * (because bytes 0xc0 and 0xdb are escaped, worst case is when
613 * the packet is all made of 0xc0 and 0xdb) + 2 (0xc0
614 * delimiters at start and end).
615 */
616 nskb = alloc_skb((len + 6) * 2 + 2, GFP_ATOMIC);
617 if (!nskb)
618 return NULL;
619
620 bt_cb(nskb)->pkt_type = pkt_type;
621
622 h5_slip_delim(nskb);
623
624 hdr[0] = h5->tx_ack << 3;
625 clear_bit(H5_TX_ACK_REQ, &h5->flags);
626
627 /* Reliable packet? */
628 if (pkt_type == HCI_ACLDATA_PKT || pkt_type == HCI_COMMAND_PKT) {
629 hdr[0] |= 1 << 7;
630 hdr[0] |= h5->tx_seq;
631 h5->tx_seq = (h5->tx_seq + 1) % 8;
632 }
633
634 hdr[1] = pkt_type | ((len & 0x0f) << 4);
635 hdr[2] = len >> 4;
636 hdr[3] = ~((hdr[0] + hdr[1] + hdr[2]) & 0xff);
637
638 BT_DBG("%s tx: seq %u ack %u crc %u rel %u type %u len %u",
639 hu->hdev->name, H5_HDR_SEQ(hdr), H5_HDR_ACK(hdr),
640 H5_HDR_CRC(hdr), H5_HDR_RELIABLE(hdr), H5_HDR_PKT_TYPE(hdr),
641 H5_HDR_LEN(hdr));
642
643 for (i = 0; i < 4; i++)
644 h5_slip_one_byte(nskb, hdr[i]);
645
646 for (i = 0; i < len; i++)
647 h5_slip_one_byte(nskb, data[i]);
648
649 h5_slip_delim(nskb);
650
651 return nskb;
652 }
653
654 static struct sk_buff *h5_dequeue(struct hci_uart *hu)
655 {
656 struct h5 *h5 = hu->priv;
657 unsigned long flags;
658 struct sk_buff *skb, *nskb;
659
660 if (h5->sleep != H5_AWAKE) {
661 const unsigned char wakeup_req[] = { 0x05, 0xfa };
662
663 if (h5->sleep == H5_WAKING_UP)
664 return NULL;
665
666 h5->sleep = H5_WAKING_UP;
667 BT_DBG("Sending wakeup request");
668
669 mod_timer(&h5->timer, jiffies + HZ / 100);
670 return h5_prepare_pkt(hu, HCI_3WIRE_LINK_PKT, wakeup_req, 2);
671 }
672
673 skb = skb_dequeue(&h5->unrel);
674 if (skb != NULL) {
675 nskb = h5_prepare_pkt(hu, bt_cb(skb)->pkt_type,
676 skb->data, skb->len);
677 if (nskb) {
678 kfree_skb(skb);
679 return nskb;
680 }
681
682 skb_queue_head(&h5->unrel, skb);
683 BT_ERR("Could not dequeue pkt because alloc_skb failed");
684 }
685
686 spin_lock_irqsave_nested(&h5->unack.lock, flags, SINGLE_DEPTH_NESTING);
687
688 if (h5->unack.qlen >= h5->tx_win)
689 goto unlock;
690
691 skb = skb_dequeue(&h5->rel);
692 if (skb != NULL) {
693 nskb = h5_prepare_pkt(hu, bt_cb(skb)->pkt_type,
694 skb->data, skb->len);
695 if (nskb) {
696 __skb_queue_tail(&h5->unack, skb);
697 mod_timer(&h5->timer, jiffies + H5_ACK_TIMEOUT);
698 spin_unlock_irqrestore(&h5->unack.lock, flags);
699 return nskb;
700 }
701
702 skb_queue_head(&h5->rel, skb);
703 BT_ERR("Could not dequeue pkt because alloc_skb failed");
704 }
705
706 unlock:
707 spin_unlock_irqrestore(&h5->unack.lock, flags);
708
709 if (test_bit(H5_TX_ACK_REQ, &h5->flags))
710 return h5_prepare_pkt(hu, HCI_3WIRE_ACK_PKT, NULL, 0);
711
712 return NULL;
713 }
714
715 static int h5_flush(struct hci_uart *hu)
716 {
717 BT_DBG("hu %p", hu);
718 return 0;
719 }
720
721 static struct hci_uart_proto h5p = {
722 .id = HCI_UART_3WIRE,
723 .open = h5_open,
724 .close = h5_close,
725 .recv = h5_recv,
726 .enqueue = h5_enqueue,
727 .dequeue = h5_dequeue,
728 .flush = h5_flush,
729 };
730
731 int __init h5_init(void)
732 {
733 int err = hci_uart_register_proto(&h5p);
734
735 if (!err)
736 BT_INFO("HCI Three-wire UART (H5) protocol initialized");
737 else
738 BT_ERR("HCI Three-wire UART (H5) protocol init failed");
739
740 return err;
741 }
742
743 int __exit h5_deinit(void)
744 {
745 return hci_uart_unregister_proto(&h5p);
746 }
Linux kernel - Deliverables
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