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Linux 3.12.39
[linux/fpc-iii.git] / drivers / bluetooth / hci_h5.c
blobdb35c542eb20c2bd3433ba83fbcb737d07ae08c9
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 skb_queue_purge(&h5->unack);
210 skb_queue_purge(&h5->rel);
211 skb_queue_purge(&h5->unrel);
212
213 del_timer(&h5->timer);
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(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 struct h5 *h5 = hu->priv;
359
360 h5_complete_rx_pkt(hu);
361 h5_reset_rx(h5);
362
363 return 0;
364 }
365
366 static int h5_rx_payload(struct hci_uart *hu, unsigned char c)
367 {
368 struct h5 *h5 = hu->priv;
369 const unsigned char *hdr = h5->rx_skb->data;
370
371 if (H5_HDR_CRC(hdr)) {
372 h5->rx_func = h5_rx_crc;
373 h5->rx_pending = 2;
374 } else {
375 h5_complete_rx_pkt(hu);
376 h5_reset_rx(h5);
377 }
378
379 return 0;
380 }
381
382 static int h5_rx_3wire_hdr(struct hci_uart *hu, unsigned char c)
383 {
384 struct h5 *h5 = hu->priv;
385 const unsigned char *hdr = h5->rx_skb->data;
386
387 BT_DBG("%s rx: seq %u ack %u crc %u rel %u type %u len %u",
388 hu->hdev->name, H5_HDR_SEQ(hdr), H5_HDR_ACK(hdr),
389 H5_HDR_CRC(hdr), H5_HDR_RELIABLE(hdr), H5_HDR_PKT_TYPE(hdr),
390 H5_HDR_LEN(hdr));
391
392 if (((hdr[0] + hdr[1] + hdr[2] + hdr[3]) & 0xff) != 0xff) {
393 BT_ERR("Invalid header checksum");
394 h5_reset_rx(h5);
395 return 0;
396 }
397
398 if (H5_HDR_RELIABLE(hdr) && H5_HDR_SEQ(hdr) != h5->tx_ack) {
399 BT_ERR("Out-of-order packet arrived (%u != %u)",
400 H5_HDR_SEQ(hdr), h5->tx_ack);
401 h5_reset_rx(h5);
402 return 0;
403 }
404
405 if (h5->state != H5_ACTIVE &&
406 H5_HDR_PKT_TYPE(hdr) != HCI_3WIRE_LINK_PKT) {
407 BT_ERR("Non-link packet received in non-active state");
408 h5_reset_rx(h5);
409 return 0;
410 }
411
412 h5->rx_func = h5_rx_payload;
413 h5->rx_pending = H5_HDR_LEN(hdr);
414
415 return 0;
416 }
417
418 static int h5_rx_pkt_start(struct hci_uart *hu, unsigned char c)
419 {
420 struct h5 *h5 = hu->priv;
421
422 if (c == SLIP_DELIMITER)
423 return 1;
424
425 h5->rx_func = h5_rx_3wire_hdr;
426 h5->rx_pending = 4;
427
428 h5->rx_skb = bt_skb_alloc(H5_MAX_LEN, GFP_ATOMIC);
429 if (!h5->rx_skb) {
430 BT_ERR("Can't allocate mem for new packet");
431 h5_reset_rx(h5);
432 return -ENOMEM;
433 }
434
435 h5->rx_skb->dev = (void *) hu->hdev;
436
437 return 0;
438 }
439
440 static int h5_rx_delimiter(struct hci_uart *hu, unsigned char c)
441 {
442 struct h5 *h5 = hu->priv;
443
444 if (c == SLIP_DELIMITER)
445 h5->rx_func = h5_rx_pkt_start;
446
447 return 1;
448 }
449
450 static void h5_unslip_one_byte(struct h5 *h5, unsigned char c)
451 {
452 const u8 delim = SLIP_DELIMITER, esc = SLIP_ESC;
453 const u8 *byte = &c;
454
455 if (!test_bit(H5_RX_ESC, &h5->flags) && c == SLIP_ESC) {
456 set_bit(H5_RX_ESC, &h5->flags);
457 return;
458 }
459
460 if (test_and_clear_bit(H5_RX_ESC, &h5->flags)) {
461 switch (c) {
462 case SLIP_ESC_DELIM:
463 byte = &delim;
464 break;
465 case SLIP_ESC_ESC:
466 byte = &esc;
467 break;
468 default:
469 BT_ERR("Invalid esc byte 0x%02hhx", c);
470 h5_reset_rx(h5);
471 return;
472 }
473 }
474
475 memcpy(skb_put(h5->rx_skb, 1), byte, 1);
476 h5->rx_pending--;
477
478 BT_DBG("unsliped 0x%02hhx, rx_pending %zu", *byte, h5->rx_pending);
479 }
480
481 static void h5_reset_rx(struct h5 *h5)
482 {
483 if (h5->rx_skb) {
484 kfree_skb(h5->rx_skb);
485 h5->rx_skb = NULL;
486 }
487
488 h5->rx_func = h5_rx_delimiter;
489 h5->rx_pending = 0;
490 clear_bit(H5_RX_ESC, &h5->flags);
491 }
492
493 static int h5_recv(struct hci_uart *hu, void *data, int count)
494 {
495 struct h5 *h5 = hu->priv;
496 unsigned char *ptr = data;
497
498 BT_DBG("%s pending %zu count %d", hu->hdev->name, h5->rx_pending,
499 count);
500
501 while (count > 0) {
502 int processed;
503
504 if (h5->rx_pending > 0) {
505 if (*ptr == SLIP_DELIMITER) {
506 BT_ERR("Too short H5 packet");
507 h5_reset_rx(h5);
508 continue;
509 }
510
511 h5_unslip_one_byte(h5, *ptr);
512
513 ptr++; count--;
514 continue;
515 }
516
517 processed = h5->rx_func(hu, *ptr);
518 if (processed < 0)
519 return processed;
520
521 ptr += processed;
522 count -= processed;
523 }
524
525 return 0;
526 }
527
528 static int h5_enqueue(struct hci_uart *hu, struct sk_buff *skb)
529 {
530 struct h5 *h5 = hu->priv;
531
532 if (skb->len > 0xfff) {
533 BT_ERR("Packet too long (%u bytes)", skb->len);
534 kfree_skb(skb);
535 return 0;
536 }
537
538 if (h5->state != H5_ACTIVE) {
539 BT_ERR("Ignoring HCI data in non-active state");
540 kfree_skb(skb);
541 return 0;
542 }
543
544 switch (bt_cb(skb)->pkt_type) {
545 case HCI_ACLDATA_PKT:
546 case HCI_COMMAND_PKT:
547 skb_queue_tail(&h5->rel, skb);
548 break;
549
550 case HCI_SCODATA_PKT:
551 skb_queue_tail(&h5->unrel, skb);
552 break;
553
554 default:
555 BT_ERR("Unknown packet type %u", bt_cb(skb)->pkt_type);
556 kfree_skb(skb);
557 break;
558 }
559
560 return 0;
561 }
562
563 static void h5_slip_delim(struct sk_buff *skb)
564 {
565 const char delim = SLIP_DELIMITER;
566
567 memcpy(skb_put(skb, 1), &delim, 1);
568 }
569
570 static void h5_slip_one_byte(struct sk_buff *skb, u8 c)
571 {
572 const char esc_delim[2] = { SLIP_ESC, SLIP_ESC_DELIM };
573 const char esc_esc[2] = { SLIP_ESC, SLIP_ESC_ESC };
574
575 switch (c) {
576 case SLIP_DELIMITER:
577 memcpy(skb_put(skb, 2), &esc_delim, 2);
578 break;
579 case SLIP_ESC:
580 memcpy(skb_put(skb, 2), &esc_esc, 2);
581 break;
582 default:
583 memcpy(skb_put(skb, 1), &c, 1);
584 }
585 }
586
587 static bool valid_packet_type(u8 type)
588 {
589 switch (type) {
590 case HCI_ACLDATA_PKT:
591 case HCI_COMMAND_PKT:
592 case HCI_SCODATA_PKT:
593 case HCI_3WIRE_LINK_PKT:
594 case HCI_3WIRE_ACK_PKT:
595 return true;
596 default:
597 return false;
598 }
599 }
600
601 static struct sk_buff *h5_prepare_pkt(struct hci_uart *hu, u8 pkt_type,
602 const u8 *data, size_t len)
603 {
604 struct h5 *h5 = hu->priv;
605 struct sk_buff *nskb;
606 u8 hdr[4];
607 int i;
608
609 if (!valid_packet_type(pkt_type)) {
610 BT_ERR("Unknown packet type %u", pkt_type);
611 return NULL;
612 }
613
614 /*
615 * Max len of packet: (original len + 4 (H5 hdr) + 2 (crc)) * 2
616 * (because bytes 0xc0 and 0xdb are escaped, worst case is when
617 * the packet is all made of 0xc0 and 0xdb) + 2 (0xc0
618 * delimiters at start and end).
619 */
620 nskb = alloc_skb((len + 6) * 2 + 2, GFP_ATOMIC);
621 if (!nskb)
622 return NULL;
623
624 bt_cb(nskb)->pkt_type = pkt_type;
625
626 h5_slip_delim(nskb);
627
628 hdr[0] = h5->tx_ack << 3;
629 clear_bit(H5_TX_ACK_REQ, &h5->flags);
630
631 /* Reliable packet? */
632 if (pkt_type == HCI_ACLDATA_PKT || pkt_type == HCI_COMMAND_PKT) {
633 hdr[0] |= 1 << 7;
634 hdr[0] |= h5->tx_seq;
635 h5->tx_seq = (h5->tx_seq + 1) % 8;
636 }
637
638 hdr[1] = pkt_type | ((len & 0x0f) << 4);
639 hdr[2] = len >> 4;
640 hdr[3] = ~((hdr[0] + hdr[1] + hdr[2]) & 0xff);
641
642 BT_DBG("%s tx: seq %u ack %u crc %u rel %u type %u len %u",
643 hu->hdev->name, H5_HDR_SEQ(hdr), H5_HDR_ACK(hdr),
644 H5_HDR_CRC(hdr), H5_HDR_RELIABLE(hdr), H5_HDR_PKT_TYPE(hdr),
645 H5_HDR_LEN(hdr));
646
647 for (i = 0; i < 4; i++)
648 h5_slip_one_byte(nskb, hdr[i]);
649
650 for (i = 0; i < len; i++)
651 h5_slip_one_byte(nskb, data[i]);
652
653 h5_slip_delim(nskb);
654
655 return nskb;
656 }
657
658 static struct sk_buff *h5_dequeue(struct hci_uart *hu)
659 {
660 struct h5 *h5 = hu->priv;
661 unsigned long flags;
662 struct sk_buff *skb, *nskb;
663
664 if (h5->sleep != H5_AWAKE) {
665 const unsigned char wakeup_req[] = { 0x05, 0xfa };
666
667 if (h5->sleep == H5_WAKING_UP)
668 return NULL;
669
670 h5->sleep = H5_WAKING_UP;
671 BT_DBG("Sending wakeup request");
672
673 mod_timer(&h5->timer, jiffies + HZ / 100);
674 return h5_prepare_pkt(hu, HCI_3WIRE_LINK_PKT, wakeup_req, 2);
675 }
676
677 if ((skb = skb_dequeue(&h5->unrel)) != NULL) {
678 nskb = h5_prepare_pkt(hu, bt_cb(skb)->pkt_type,
679 skb->data, skb->len);
680 if (nskb) {
681 kfree_skb(skb);
682 return nskb;
683 }
684
685 skb_queue_head(&h5->unrel, skb);
686 BT_ERR("Could not dequeue pkt because alloc_skb failed");
687 }
688
689 spin_lock_irqsave_nested(&h5->unack.lock, flags, SINGLE_DEPTH_NESTING);
690
691 if (h5->unack.qlen >= h5->tx_win)
692 goto unlock;
693
694 if ((skb = skb_dequeue(&h5->rel)) != NULL) {
695 nskb = h5_prepare_pkt(hu, bt_cb(skb)->pkt_type,
696 skb->data, skb->len);
697 if (nskb) {
698 __skb_queue_tail(&h5->unack, skb);
699 mod_timer(&h5->timer, jiffies + H5_ACK_TIMEOUT);
700 spin_unlock_irqrestore(&h5->unack.lock, flags);
701 return nskb;
702 }
703
704 skb_queue_head(&h5->rel, skb);
705 BT_ERR("Could not dequeue pkt because alloc_skb failed");
706 }
707
708 unlock:
709 spin_unlock_irqrestore(&h5->unack.lock, flags);
710
711 if (test_bit(H5_TX_ACK_REQ, &h5->flags))
712 return h5_prepare_pkt(hu, HCI_3WIRE_ACK_PKT, NULL, 0);
713
714 return NULL;
715 }
716
717 static int h5_flush(struct hci_uart *hu)
718 {
719 BT_DBG("hu %p", hu);
720 return 0;
721 }
722
723 static struct hci_uart_proto h5p = {
724 .id = HCI_UART_3WIRE,
725 .open = h5_open,
726 .close = h5_close,
727 .recv = h5_recv,
728 .enqueue = h5_enqueue,
729 .dequeue = h5_dequeue,
730 .flush = h5_flush,
731 };
732
733 int __init h5_init(void)
734 {
735 int err = hci_uart_register_proto(&h5p);
736
737 if (!err)
738 BT_INFO("HCI Three-wire UART (H5) protocol initialized");
739 else
740 BT_ERR("HCI Three-wire UART (H5) protocol init failed");
741
742 return err;
743 }
744
745 int __exit h5_deinit(void)
746 {
747 return hci_uart_unregister_proto(&h5p);
748 }
Linux with added FPC-III support