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1/*
2 *
3 * Bluetooth HCI UART driver
4 *
5 * Copyright (C) 2002-2003 Fabrizio Gennari <fabrizio.gennari@philips.com>
6 * Copyright (C) 2004-2005 Marcel Holtmann <marcel@holtmann.org>
7 *
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 *
23 */
24
25#include <linux/module.h>
26
27#include <linux/kernel.h>
28#include <linux/init.h>
29#include <linux/types.h>
30#include <linux/fcntl.h>
31#include <linux/interrupt.h>
32#include <linux/ptrace.h>
33#include <linux/poll.h>
34
35#include <linux/slab.h>
36#include <linux/tty.h>
37#include <linux/errno.h>
38#include <linux/string.h>
39#include <linux/signal.h>
40#include <linux/ioctl.h>
41#include <linux/skbuff.h>
42#include <linux/bitrev.h>
43#include <asm/unaligned.h>
44
45#include <net/bluetooth/bluetooth.h>
46#include <net/bluetooth/hci_core.h>
47
48#include "hci_uart.h"
49
50#define VERSION "0.3"
51
52static int txcrc = 1;
53static int hciextn = 1;
54
55#define BCSP_TXWINSIZE 4
56
57#define BCSP_ACK_PKT 0x05
58#define BCSP_LE_PKT 0x06
59
60struct bcsp_struct {
61 struct sk_buff_head unack; /* Unack'ed packets queue */
62 struct sk_buff_head rel; /* Reliable packets queue */
63 struct sk_buff_head unrel; /* Unreliable packets queue */
64
65 unsigned long rx_count;
66 struct sk_buff *rx_skb;
67 u8 rxseq_txack; /* rxseq == txack. */
68 u8 rxack; /* Last packet sent by us that the peer ack'ed */
69 struct timer_list tbcsp;
70
71 enum {
72 BCSP_W4_PKT_DELIMITER,
73 BCSP_W4_PKT_START,
74 BCSP_W4_BCSP_HDR,
75 BCSP_W4_DATA,
76 BCSP_W4_CRC
77 } rx_state;
78
79 enum {
80 BCSP_ESCSTATE_NOESC,
81 BCSP_ESCSTATE_ESC
82 } rx_esc_state;
83
84 u8 use_crc;
85 u16 message_crc;
86 u8 txack_req; /* Do we need to send ack's to the peer? */
87
88 /* Reliable packet sequence number - used to assign seq to each rel pkt. */
89 u8 msgq_txseq;
90};
91
92/* ---- BCSP CRC calculation ---- */
93
94/* Table for calculating CRC for polynomial 0x1021, LSB processed first,
95initial value 0xffff, bits shifted in reverse order. */
96
97static const u16 crc_table[] = {
98 0x0000, 0x1081, 0x2102, 0x3183,
99 0x4204, 0x5285, 0x6306, 0x7387,
100 0x8408, 0x9489, 0xa50a, 0xb58b,
101 0xc60c, 0xd68d, 0xe70e, 0xf78f
102};
103
104/* Initialise the crc calculator */
105#define BCSP_CRC_INIT(x) x = 0xffff
106
107/*
108 Update crc with next data byte
109
110 Implementation note
111 The data byte is treated as two nibbles. The crc is generated
112 in reverse, i.e., bits are fed into the register from the top.
113*/
114static void bcsp_crc_update(u16 *crc, u8 d)
115{
116 u16 reg = *crc;
117
118 reg = (reg >> 4) ^ crc_table[(reg ^ d) & 0x000f];
119 reg = (reg >> 4) ^ crc_table[(reg ^ (d >> 4)) & 0x000f];
120
121 *crc = reg;
122}
123
124/* ---- BCSP core ---- */
125
126static void bcsp_slip_msgdelim(struct sk_buff *skb)
127{
128 const char pkt_delim = 0xc0;
129
130 memcpy(skb_put(skb, 1), &pkt_delim, 1);
131}
132
133static void bcsp_slip_one_byte(struct sk_buff *skb, u8 c)
134{
135 const char esc_c0[2] = { 0xdb, 0xdc };
136 const char esc_db[2] = { 0xdb, 0xdd };
137
138 switch (c) {
139 case 0xc0:
140 memcpy(skb_put(skb, 2), &esc_c0, 2);
141 break;
142 case 0xdb:
143 memcpy(skb_put(skb, 2), &esc_db, 2);
144 break;
145 default:
146 memcpy(skb_put(skb, 1), &c, 1);
147 }
148}
149
150static int bcsp_enqueue(struct hci_uart *hu, struct sk_buff *skb)
151{
152 struct bcsp_struct *bcsp = hu->priv;
153
154 if (skb->len > 0xFFF) {
155 BT_ERR("Packet too long");
156 kfree_skb(skb);
157 return 0;
158 }
159
160 switch (bt_cb(skb)->pkt_type) {
161 case HCI_ACLDATA_PKT:
162 case HCI_COMMAND_PKT:
163 skb_queue_tail(&bcsp->rel, skb);
164 break;
165
166 case HCI_SCODATA_PKT:
167 skb_queue_tail(&bcsp->unrel, skb);
168 break;
169
170 default:
171 BT_ERR("Unknown packet type");
172 kfree_skb(skb);
173 break;
174 }
175
176 return 0;
177}
178
179static struct sk_buff *bcsp_prepare_pkt(struct bcsp_struct *bcsp, u8 *data,
180 int len, int pkt_type)
181{
182 struct sk_buff *nskb;
183 u8 hdr[4], chan;
184 u16 BCSP_CRC_INIT(bcsp_txmsg_crc);
185 int rel, i;
186
187 switch (pkt_type) {
188 case HCI_ACLDATA_PKT:
189 chan = 6; /* BCSP ACL channel */
190 rel = 1; /* reliable channel */
191 break;
192 case HCI_COMMAND_PKT:
193 chan = 5; /* BCSP cmd/evt channel */
194 rel = 1; /* reliable channel */
195 break;
196 case HCI_SCODATA_PKT:
197 chan = 7; /* BCSP SCO channel */
198 rel = 0; /* unreliable channel */
199 break;
200 case BCSP_LE_PKT:
201 chan = 1; /* BCSP LE channel */
202 rel = 0; /* unreliable channel */
203 break;
204 case BCSP_ACK_PKT:
205 chan = 0; /* BCSP internal channel */
206 rel = 0; /* unreliable channel */
207 break;
208 default:
209 BT_ERR("Unknown packet type");
210 return NULL;
211 }
212
213 if (hciextn && chan == 5) {
214 __le16 opcode = ((struct hci_command_hdr *)data)->opcode;
215
216 /* Vendor specific commands */
217 if (hci_opcode_ogf(__le16_to_cpu(opcode)) == 0x3f) {
218 u8 desc = *(data + HCI_COMMAND_HDR_SIZE);
219 if ((desc & 0xf0) == 0xc0) {
220 data += HCI_COMMAND_HDR_SIZE + 1;
221 len -= HCI_COMMAND_HDR_SIZE + 1;
222 chan = desc & 0x0f;
223 }
224 }
225 }
226
227 /* Max len of packet: (original len +4(bcsp hdr) +2(crc))*2
228 (because bytes 0xc0 and 0xdb are escaped, worst case is
229 when the packet is all made of 0xc0 and 0xdb :) )
230 + 2 (0xc0 delimiters at start and end). */
231
232 nskb = alloc_skb((len + 6) * 2 + 2, GFP_ATOMIC);
233 if (!nskb)
234 return NULL;
235
236 bt_cb(nskb)->pkt_type = pkt_type;
237
238 bcsp_slip_msgdelim(nskb);
239
240 hdr[0] = bcsp->rxseq_txack << 3;
241 bcsp->txack_req = 0;
242 BT_DBG("We request packet no %u to card", bcsp->rxseq_txack);
243
244 if (rel) {
245 hdr[0] |= 0x80 + bcsp->msgq_txseq;
246 BT_DBG("Sending packet with seqno %u", bcsp->msgq_txseq);
247 bcsp->msgq_txseq = (bcsp->msgq_txseq + 1) & 0x07;
248 }
249
250 if (bcsp->use_crc)
251 hdr[0] |= 0x40;
252
253 hdr[1] = ((len << 4) & 0xff) | chan;
254 hdr[2] = len >> 4;
255 hdr[3] = ~(hdr[0] + hdr[1] + hdr[2]);
256
257 /* Put BCSP header */
258 for (i = 0; i < 4; i++) {
259 bcsp_slip_one_byte(nskb, hdr[i]);
260
261 if (bcsp->use_crc)
262 bcsp_crc_update(&bcsp_txmsg_crc, hdr[i]);
263 }
264
265 /* Put payload */
266 for (i = 0; i < len; i++) {
267 bcsp_slip_one_byte(nskb, data[i]);
268
269 if (bcsp->use_crc)
270 bcsp_crc_update(&bcsp_txmsg_crc, data[i]);
271 }
272
273 /* Put CRC */
274 if (bcsp->use_crc) {
275 bcsp_txmsg_crc = bitrev16(bcsp_txmsg_crc);
276 bcsp_slip_one_byte(nskb, (u8) ((bcsp_txmsg_crc >> 8) & 0x00ff));
277 bcsp_slip_one_byte(nskb, (u8) (bcsp_txmsg_crc & 0x00ff));
278 }
279
280 bcsp_slip_msgdelim(nskb);
281 return nskb;
282}
283
284/* This is a rewrite of pkt_avail in ABCSP */
285static struct sk_buff *bcsp_dequeue(struct hci_uart *hu)
286{
287 struct bcsp_struct *bcsp = hu->priv;
288 unsigned long flags;
289 struct sk_buff *skb;
290
291 /* First of all, check for unreliable messages in the queue,
292 since they have priority */
293
294 if ((skb = skb_dequeue(&bcsp->unrel)) != NULL) {
295 struct sk_buff *nskb = bcsp_prepare_pkt(bcsp, skb->data, skb->len, bt_cb(skb)->pkt_type);
296 if (nskb) {
297 kfree_skb(skb);
298 return nskb;
299 } else {
300 skb_queue_head(&bcsp->unrel, skb);
301 BT_ERR("Could not dequeue pkt because alloc_skb failed");
302 }
303 }
304
305 /* Now, try to send a reliable pkt. We can only send a
306 reliable packet if the number of packets sent but not yet ack'ed
307 is < than the winsize */
308
309 spin_lock_irqsave_nested(&bcsp->unack.lock, flags, SINGLE_DEPTH_NESTING);
310
311 if (bcsp->unack.qlen < BCSP_TXWINSIZE && (skb = skb_dequeue(&bcsp->rel)) != NULL) {
312 struct sk_buff *nskb = bcsp_prepare_pkt(bcsp, skb->data, skb->len, bt_cb(skb)->pkt_type);
313 if (nskb) {
314 __skb_queue_tail(&bcsp->unack, skb);
315 mod_timer(&bcsp->tbcsp, jiffies + HZ / 4);
316 spin_unlock_irqrestore(&bcsp->unack.lock, flags);
317 return nskb;
318 } else {
319 skb_queue_head(&bcsp->rel, skb);
320 BT_ERR("Could not dequeue pkt because alloc_skb failed");
321 }
322 }
323
324 spin_unlock_irqrestore(&bcsp->unack.lock, flags);
325
326 /* We could not send a reliable packet, either because there are
327 none or because there are too many unack'ed pkts. Did we receive
328 any packets we have not acknowledged yet ? */
329
330 if (bcsp->txack_req) {
331 /* if so, craft an empty ACK pkt and send it on BCSP unreliable
332 channel 0 */
333 struct sk_buff *nskb = bcsp_prepare_pkt(bcsp, NULL, 0, BCSP_ACK_PKT);
334 return nskb;
335 }
336
337 /* We have nothing to send */
338 return NULL;
339}
340
341static int bcsp_flush(struct hci_uart *hu)
342{
343 BT_DBG("hu %p", hu);
344 return 0;
345}
346
347/* Remove ack'ed packets */
348static void bcsp_pkt_cull(struct bcsp_struct *bcsp)
349{
350 struct sk_buff *skb, *tmp;
351 unsigned long flags;
352 int i, pkts_to_be_removed;
353 u8 seqno;
354
355 spin_lock_irqsave(&bcsp->unack.lock, flags);
356
357 pkts_to_be_removed = skb_queue_len(&bcsp->unack);
358 seqno = bcsp->msgq_txseq;
359
360 while (pkts_to_be_removed) {
361 if (bcsp->rxack == seqno)
362 break;
363 pkts_to_be_removed--;
364 seqno = (seqno - 1) & 0x07;
365 }
366
367 if (bcsp->rxack != seqno)
368 BT_ERR("Peer acked invalid packet");
369
370 BT_DBG("Removing %u pkts out of %u, up to seqno %u",
371 pkts_to_be_removed, skb_queue_len(&bcsp->unack),
372 (seqno - 1) & 0x07);
373
374 i = 0;
375 skb_queue_walk_safe(&bcsp->unack, skb, tmp) {
376 if (i >= pkts_to_be_removed)
377 break;
378 i++;
379
380 __skb_unlink(skb, &bcsp->unack);
381 kfree_skb(skb);
382 }
383
384 if (skb_queue_empty(&bcsp->unack))
385 del_timer(&bcsp->tbcsp);
386
387 spin_unlock_irqrestore(&bcsp->unack.lock, flags);
388
389 if (i != pkts_to_be_removed)
390 BT_ERR("Removed only %u out of %u pkts", i, pkts_to_be_removed);
391}
392
393/* Handle BCSP link-establishment packets. When we
394 detect a "sync" packet, symptom that the BT module has reset,
395 we do nothing :) (yet) */
396static void bcsp_handle_le_pkt(struct hci_uart *hu)
397{
398 struct bcsp_struct *bcsp = hu->priv;
399 u8 conf_pkt[4] = { 0xad, 0xef, 0xac, 0xed };
400 u8 conf_rsp_pkt[4] = { 0xde, 0xad, 0xd0, 0xd0 };
401 u8 sync_pkt[4] = { 0xda, 0xdc, 0xed, 0xed };
402
403 /* spot "conf" pkts and reply with a "conf rsp" pkt */
404 if (bcsp->rx_skb->data[1] >> 4 == 4 && bcsp->rx_skb->data[2] == 0 &&
405 !memcmp(&bcsp->rx_skb->data[4], conf_pkt, 4)) {
406 struct sk_buff *nskb = alloc_skb(4, GFP_ATOMIC);
407
408 BT_DBG("Found a LE conf pkt");
409 if (!nskb)
410 return;
411 memcpy(skb_put(nskb, 4), conf_rsp_pkt, 4);
412 bt_cb(nskb)->pkt_type = BCSP_LE_PKT;
413
414 skb_queue_head(&bcsp->unrel, nskb);
415 hci_uart_tx_wakeup(hu);
416 }
417 /* Spot "sync" pkts. If we find one...disaster! */
418 else if (bcsp->rx_skb->data[1] >> 4 == 4 && bcsp->rx_skb->data[2] == 0 &&
419 !memcmp(&bcsp->rx_skb->data[4], sync_pkt, 4)) {
420 BT_ERR("Found a LE sync pkt, card has reset");
421 }
422}
423
424static inline void bcsp_unslip_one_byte(struct bcsp_struct *bcsp, unsigned char byte)
425{
426 const u8 c0 = 0xc0, db = 0xdb;
427
428 switch (bcsp->rx_esc_state) {
429 case BCSP_ESCSTATE_NOESC:
430 switch (byte) {
431 case 0xdb:
432 bcsp->rx_esc_state = BCSP_ESCSTATE_ESC;
433 break;
434 default:
435 memcpy(skb_put(bcsp->rx_skb, 1), &byte, 1);
436 if ((bcsp->rx_skb-> data[0] & 0x40) != 0 &&
437 bcsp->rx_state != BCSP_W4_CRC)
438 bcsp_crc_update(&bcsp->message_crc, byte);
439 bcsp->rx_count--;
440 }
441 break;
442
443 case BCSP_ESCSTATE_ESC:
444 switch (byte) {
445 case 0xdc:
446 memcpy(skb_put(bcsp->rx_skb, 1), &c0, 1);
447 if ((bcsp->rx_skb-> data[0] & 0x40) != 0 &&
448 bcsp->rx_state != BCSP_W4_CRC)
449 bcsp_crc_update(&bcsp-> message_crc, 0xc0);
450 bcsp->rx_esc_state = BCSP_ESCSTATE_NOESC;
451 bcsp->rx_count--;
452 break;
453
454 case 0xdd:
455 memcpy(skb_put(bcsp->rx_skb, 1), &db, 1);
456 if ((bcsp->rx_skb-> data[0] & 0x40) != 0 &&
457 bcsp->rx_state != BCSP_W4_CRC)
458 bcsp_crc_update(&bcsp-> message_crc, 0xdb);
459 bcsp->rx_esc_state = BCSP_ESCSTATE_NOESC;
460 bcsp->rx_count--;
461 break;
462
463 default:
464 BT_ERR ("Invalid byte %02x after esc byte", byte);
465 kfree_skb(bcsp->rx_skb);
466 bcsp->rx_skb = NULL;
467 bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
468 bcsp->rx_count = 0;
469 }
470 }
471}
472
473static void bcsp_complete_rx_pkt(struct hci_uart *hu)
474{
475 struct bcsp_struct *bcsp = hu->priv;
476 int pass_up;
477
478 if (bcsp->rx_skb->data[0] & 0x80) { /* reliable pkt */
479 BT_DBG("Received seqno %u from card", bcsp->rxseq_txack);
480 bcsp->rxseq_txack++;
481 bcsp->rxseq_txack %= 0x8;
482 bcsp->txack_req = 1;
483
484 /* If needed, transmit an ack pkt */
485 hci_uart_tx_wakeup(hu);
486 }
487
488 bcsp->rxack = (bcsp->rx_skb->data[0] >> 3) & 0x07;
489 BT_DBG("Request for pkt %u from card", bcsp->rxack);
490
491 bcsp_pkt_cull(bcsp);
492 if ((bcsp->rx_skb->data[1] & 0x0f) == 6 &&
493 bcsp->rx_skb->data[0] & 0x80) {
494 bt_cb(bcsp->rx_skb)->pkt_type = HCI_ACLDATA_PKT;
495 pass_up = 1;
496 } else if ((bcsp->rx_skb->data[1] & 0x0f) == 5 &&
497 bcsp->rx_skb->data[0] & 0x80) {
498 bt_cb(bcsp->rx_skb)->pkt_type = HCI_EVENT_PKT;
499 pass_up = 1;
500 } else if ((bcsp->rx_skb->data[1] & 0x0f) == 7) {
501 bt_cb(bcsp->rx_skb)->pkt_type = HCI_SCODATA_PKT;
502 pass_up = 1;
503 } else if ((bcsp->rx_skb->data[1] & 0x0f) == 1 &&
504 !(bcsp->rx_skb->data[0] & 0x80)) {
505 bcsp_handle_le_pkt(hu);
506 pass_up = 0;
507 } else
508 pass_up = 0;
509
510 if (!pass_up) {
511 struct hci_event_hdr hdr;
512 u8 desc = (bcsp->rx_skb->data[1] & 0x0f);
513
514 if (desc != 0 && desc != 1) {
515 if (hciextn) {
516 desc |= 0xc0;
517 skb_pull(bcsp->rx_skb, 4);
518 memcpy(skb_push(bcsp->rx_skb, 1), &desc, 1);
519
520 hdr.evt = 0xff;
521 hdr.plen = bcsp->rx_skb->len;
522 memcpy(skb_push(bcsp->rx_skb, HCI_EVENT_HDR_SIZE), &hdr, HCI_EVENT_HDR_SIZE);
523 bt_cb(bcsp->rx_skb)->pkt_type = HCI_EVENT_PKT;
524
525 hci_recv_frame(bcsp->rx_skb);
526 } else {
527 BT_ERR ("Packet for unknown channel (%u %s)",
528 bcsp->rx_skb->data[1] & 0x0f,
529 bcsp->rx_skb->data[0] & 0x80 ?
530 "reliable" : "unreliable");
531 kfree_skb(bcsp->rx_skb);
532 }
533 } else
534 kfree_skb(bcsp->rx_skb);
535 } else {
536 /* Pull out BCSP hdr */
537 skb_pull(bcsp->rx_skb, 4);
538
539 hci_recv_frame(bcsp->rx_skb);
540 }
541
542 bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
543 bcsp->rx_skb = NULL;
544}
545
546static u16 bscp_get_crc(struct bcsp_struct *bcsp)
547{
548 return get_unaligned_be16(&bcsp->rx_skb->data[bcsp->rx_skb->len - 2]);
549}
550
551/* Recv data */
552static int bcsp_recv(struct hci_uart *hu, void *data, int count)
553{
554 struct bcsp_struct *bcsp = hu->priv;
555 register unsigned char *ptr;
556
557 BT_DBG("hu %p count %d rx_state %d rx_count %ld",
558 hu, count, bcsp->rx_state, bcsp->rx_count);
559
560 ptr = data;
561 while (count) {
562 if (bcsp->rx_count) {
563 if (*ptr == 0xc0) {
564 BT_ERR("Short BCSP packet");
565 kfree_skb(bcsp->rx_skb);
566 bcsp->rx_state = BCSP_W4_PKT_START;
567 bcsp->rx_count = 0;
568 } else
569 bcsp_unslip_one_byte(bcsp, *ptr);
570
571 ptr++; count--;
572 continue;
573 }
574
575 switch (bcsp->rx_state) {
576 case BCSP_W4_BCSP_HDR:
577 if ((0xff & (u8) ~ (bcsp->rx_skb->data[0] + bcsp->rx_skb->data[1] +
578 bcsp->rx_skb->data[2])) != bcsp->rx_skb->data[3]) {
579 BT_ERR("Error in BCSP hdr checksum");
580 kfree_skb(bcsp->rx_skb);
581 bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
582 bcsp->rx_count = 0;
583 continue;
584 }
585 if (bcsp->rx_skb->data[0] & 0x80 /* reliable pkt */
586 && (bcsp->rx_skb->data[0] & 0x07) != bcsp->rxseq_txack) {
587 BT_ERR ("Out-of-order packet arrived, got %u expected %u",
588 bcsp->rx_skb->data[0] & 0x07, bcsp->rxseq_txack);
589
590 kfree_skb(bcsp->rx_skb);
591 bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
592 bcsp->rx_count = 0;
593 continue;
594 }
595 bcsp->rx_state = BCSP_W4_DATA;
596 bcsp->rx_count = (bcsp->rx_skb->data[1] >> 4) +
597 (bcsp->rx_skb->data[2] << 4); /* May be 0 */
598 continue;
599
600 case BCSP_W4_DATA:
601 if (bcsp->rx_skb->data[0] & 0x40) { /* pkt with crc */
602 bcsp->rx_state = BCSP_W4_CRC;
603 bcsp->rx_count = 2;
604 } else
605 bcsp_complete_rx_pkt(hu);
606 continue;
607
608 case BCSP_W4_CRC:
609 if (bitrev16(bcsp->message_crc) != bscp_get_crc(bcsp)) {
610 BT_ERR ("Checksum failed: computed %04x received %04x",
611 bitrev16(bcsp->message_crc),
612 bscp_get_crc(bcsp));
613
614 kfree_skb(bcsp->rx_skb);
615 bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
616 bcsp->rx_count = 0;
617 continue;
618 }
619 skb_trim(bcsp->rx_skb, bcsp->rx_skb->len - 2);
620 bcsp_complete_rx_pkt(hu);
621 continue;
622
623 case BCSP_W4_PKT_DELIMITER:
624 switch (*ptr) {
625 case 0xc0:
626 bcsp->rx_state = BCSP_W4_PKT_START;
627 break;
628 default:
629 /*BT_ERR("Ignoring byte %02x", *ptr);*/
630 break;
631 }
632 ptr++; count--;
633 break;
634
635 case BCSP_W4_PKT_START:
636 switch (*ptr) {
637 case 0xc0:
638 ptr++; count--;
639 break;
640
641 default:
642 bcsp->rx_state = BCSP_W4_BCSP_HDR;
643 bcsp->rx_count = 4;
644 bcsp->rx_esc_state = BCSP_ESCSTATE_NOESC;
645 BCSP_CRC_INIT(bcsp->message_crc);
646
647 /* Do not increment ptr or decrement count
648 * Allocate packet. Max len of a BCSP pkt=
649 * 0xFFF (payload) +4 (header) +2 (crc) */
650
651 bcsp->rx_skb = bt_skb_alloc(0x1005, GFP_ATOMIC);
652 if (!bcsp->rx_skb) {
653 BT_ERR("Can't allocate mem for new packet");
654 bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
655 bcsp->rx_count = 0;
656 return 0;
657 }
658 bcsp->rx_skb->dev = (void *) hu->hdev;
659 break;
660 }
661 break;
662 }
663 }
664 return count;
665}
666
667 /* Arrange to retransmit all messages in the relq. */
668static void bcsp_timed_event(unsigned long arg)
669{
670 struct hci_uart *hu = (struct hci_uart *) arg;
671 struct bcsp_struct *bcsp = hu->priv;
672 struct sk_buff *skb;
673 unsigned long flags;
674
675 BT_DBG("hu %p retransmitting %u pkts", hu, bcsp->unack.qlen);
676
677 spin_lock_irqsave_nested(&bcsp->unack.lock, flags, SINGLE_DEPTH_NESTING);
678
679 while ((skb = __skb_dequeue_tail(&bcsp->unack)) != NULL) {
680 bcsp->msgq_txseq = (bcsp->msgq_txseq - 1) & 0x07;
681 skb_queue_head(&bcsp->rel, skb);
682 }
683
684 spin_unlock_irqrestore(&bcsp->unack.lock, flags);
685
686 hci_uart_tx_wakeup(hu);
687}
688
689static int bcsp_open(struct hci_uart *hu)
690{
691 struct bcsp_struct *bcsp;
692
693 BT_DBG("hu %p", hu);
694
695 bcsp = kzalloc(sizeof(*bcsp), GFP_ATOMIC);
696 if (!bcsp)
697 return -ENOMEM;
698
699 hu->priv = bcsp;
700 skb_queue_head_init(&bcsp->unack);
701 skb_queue_head_init(&bcsp->rel);
702 skb_queue_head_init(&bcsp->unrel);
703
704 init_timer(&bcsp->tbcsp);
705 bcsp->tbcsp.function = bcsp_timed_event;
706 bcsp->tbcsp.data = (u_long) hu;
707
708 bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
709
710 if (txcrc)
711 bcsp->use_crc = 1;
712
713 return 0;
714}
715
716static int bcsp_close(struct hci_uart *hu)
717{
718 struct bcsp_struct *bcsp = hu->priv;
719 hu->priv = NULL;
720
721 BT_DBG("hu %p", hu);
722
723 skb_queue_purge(&bcsp->unack);
724 skb_queue_purge(&bcsp->rel);
725 skb_queue_purge(&bcsp->unrel);
726 del_timer(&bcsp->tbcsp);
727
728 kfree(bcsp);
729 return 0;
730}
731
732static struct hci_uart_proto bcsp = {
733 .id = HCI_UART_BCSP,
734 .open = bcsp_open,
735 .close = bcsp_close,
736 .enqueue = bcsp_enqueue,
737 .dequeue = bcsp_dequeue,
738 .recv = bcsp_recv,
739 .flush = bcsp_flush
740};
741
742int __init bcsp_init(void)
743{
744 int err = hci_uart_register_proto(&bcsp);
745
746 if (!err)
747 BT_INFO("HCI BCSP protocol initialized");
748 else
749 BT_ERR("HCI BCSP protocol registration failed");
750
751 return err;
752}
753
754int __exit bcsp_deinit(void)
755{
756 return hci_uart_unregister_proto(&bcsp);
757}
758
759module_param(txcrc, bool, 0644);
760MODULE_PARM_DESC(txcrc, "Transmit CRC with every BCSP packet");
761
762module_param(hciextn, bool, 0644);
763MODULE_PARM_DESC(hciextn, "Convert HCI Extensions into BCSP packets");
1/*
2 *
3 * Bluetooth HCI UART driver
4 *
5 * Copyright (C) 2002-2003 Fabrizio Gennari <fabrizio.gennari@philips.com>
6 * Copyright (C) 2004-2005 Marcel Holtmann <marcel@holtmann.org>
7 *
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 *
23 */
24
25#include <linux/module.h>
26
27#include <linux/kernel.h>
28#include <linux/init.h>
29#include <linux/types.h>
30#include <linux/fcntl.h>
31#include <linux/interrupt.h>
32#include <linux/ptrace.h>
33#include <linux/poll.h>
34
35#include <linux/slab.h>
36#include <linux/tty.h>
37#include <linux/errno.h>
38#include <linux/string.h>
39#include <linux/signal.h>
40#include <linux/ioctl.h>
41#include <linux/skbuff.h>
42#include <linux/bitrev.h>
43#include <asm/unaligned.h>
44
45#include <net/bluetooth/bluetooth.h>
46#include <net/bluetooth/hci_core.h>
47
48#include "hci_uart.h"
49
50static bool txcrc = true;
51static bool hciextn = true;
52
53#define BCSP_TXWINSIZE 4
54
55#define BCSP_ACK_PKT 0x05
56#define BCSP_LE_PKT 0x06
57
58struct bcsp_struct {
59 struct sk_buff_head unack; /* Unack'ed packets queue */
60 struct sk_buff_head rel; /* Reliable packets queue */
61 struct sk_buff_head unrel; /* Unreliable packets queue */
62
63 unsigned long rx_count;
64 struct sk_buff *rx_skb;
65 u8 rxseq_txack; /* rxseq == txack. */
66 u8 rxack; /* Last packet sent by us that the peer ack'ed */
67 struct timer_list tbcsp;
68
69 enum {
70 BCSP_W4_PKT_DELIMITER,
71 BCSP_W4_PKT_START,
72 BCSP_W4_BCSP_HDR,
73 BCSP_W4_DATA,
74 BCSP_W4_CRC
75 } rx_state;
76
77 enum {
78 BCSP_ESCSTATE_NOESC,
79 BCSP_ESCSTATE_ESC
80 } rx_esc_state;
81
82 u8 use_crc;
83 u16 message_crc;
84 u8 txack_req; /* Do we need to send ack's to the peer? */
85
86 /* Reliable packet sequence number - used to assign seq to each rel pkt. */
87 u8 msgq_txseq;
88};
89
90/* ---- BCSP CRC calculation ---- */
91
92/* Table for calculating CRC for polynomial 0x1021, LSB processed first,
93initial value 0xffff, bits shifted in reverse order. */
94
95static const u16 crc_table[] = {
96 0x0000, 0x1081, 0x2102, 0x3183,
97 0x4204, 0x5285, 0x6306, 0x7387,
98 0x8408, 0x9489, 0xa50a, 0xb58b,
99 0xc60c, 0xd68d, 0xe70e, 0xf78f
100};
101
102/* Initialise the crc calculator */
103#define BCSP_CRC_INIT(x) x = 0xffff
104
105/*
106 Update crc with next data byte
107
108 Implementation note
109 The data byte is treated as two nibbles. The crc is generated
110 in reverse, i.e., bits are fed into the register from the top.
111*/
112static void bcsp_crc_update(u16 *crc, u8 d)
113{
114 u16 reg = *crc;
115
116 reg = (reg >> 4) ^ crc_table[(reg ^ d) & 0x000f];
117 reg = (reg >> 4) ^ crc_table[(reg ^ (d >> 4)) & 0x000f];
118
119 *crc = reg;
120}
121
122/* ---- BCSP core ---- */
123
124static void bcsp_slip_msgdelim(struct sk_buff *skb)
125{
126 const char pkt_delim = 0xc0;
127
128 memcpy(skb_put(skb, 1), &pkt_delim, 1);
129}
130
131static void bcsp_slip_one_byte(struct sk_buff *skb, u8 c)
132{
133 const char esc_c0[2] = { 0xdb, 0xdc };
134 const char esc_db[2] = { 0xdb, 0xdd };
135
136 switch (c) {
137 case 0xc0:
138 memcpy(skb_put(skb, 2), &esc_c0, 2);
139 break;
140 case 0xdb:
141 memcpy(skb_put(skb, 2), &esc_db, 2);
142 break;
143 default:
144 memcpy(skb_put(skb, 1), &c, 1);
145 }
146}
147
148static int bcsp_enqueue(struct hci_uart *hu, struct sk_buff *skb)
149{
150 struct bcsp_struct *bcsp = hu->priv;
151
152 if (skb->len > 0xFFF) {
153 BT_ERR("Packet too long");
154 kfree_skb(skb);
155 return 0;
156 }
157
158 switch (hci_skb_pkt_type(skb)) {
159 case HCI_ACLDATA_PKT:
160 case HCI_COMMAND_PKT:
161 skb_queue_tail(&bcsp->rel, skb);
162 break;
163
164 case HCI_SCODATA_PKT:
165 skb_queue_tail(&bcsp->unrel, skb);
166 break;
167
168 default:
169 BT_ERR("Unknown packet type");
170 kfree_skb(skb);
171 break;
172 }
173
174 return 0;
175}
176
177static struct sk_buff *bcsp_prepare_pkt(struct bcsp_struct *bcsp, u8 *data,
178 int len, int pkt_type)
179{
180 struct sk_buff *nskb;
181 u8 hdr[4], chan;
182 u16 BCSP_CRC_INIT(bcsp_txmsg_crc);
183 int rel, i;
184
185 switch (pkt_type) {
186 case HCI_ACLDATA_PKT:
187 chan = 6; /* BCSP ACL channel */
188 rel = 1; /* reliable channel */
189 break;
190 case HCI_COMMAND_PKT:
191 chan = 5; /* BCSP cmd/evt channel */
192 rel = 1; /* reliable channel */
193 break;
194 case HCI_SCODATA_PKT:
195 chan = 7; /* BCSP SCO channel */
196 rel = 0; /* unreliable channel */
197 break;
198 case BCSP_LE_PKT:
199 chan = 1; /* BCSP LE channel */
200 rel = 0; /* unreliable channel */
201 break;
202 case BCSP_ACK_PKT:
203 chan = 0; /* BCSP internal channel */
204 rel = 0; /* unreliable channel */
205 break;
206 default:
207 BT_ERR("Unknown packet type");
208 return NULL;
209 }
210
211 if (hciextn && chan == 5) {
212 __le16 opcode = ((struct hci_command_hdr *)data)->opcode;
213
214 /* Vendor specific commands */
215 if (hci_opcode_ogf(__le16_to_cpu(opcode)) == 0x3f) {
216 u8 desc = *(data + HCI_COMMAND_HDR_SIZE);
217 if ((desc & 0xf0) == 0xc0) {
218 data += HCI_COMMAND_HDR_SIZE + 1;
219 len -= HCI_COMMAND_HDR_SIZE + 1;
220 chan = desc & 0x0f;
221 }
222 }
223 }
224
225 /* Max len of packet: (original len +4(bcsp hdr) +2(crc))*2
226 (because bytes 0xc0 and 0xdb are escaped, worst case is
227 when the packet is all made of 0xc0 and 0xdb :) )
228 + 2 (0xc0 delimiters at start and end). */
229
230 nskb = alloc_skb((len + 6) * 2 + 2, GFP_ATOMIC);
231 if (!nskb)
232 return NULL;
233
234 hci_skb_pkt_type(nskb) = pkt_type;
235
236 bcsp_slip_msgdelim(nskb);
237
238 hdr[0] = bcsp->rxseq_txack << 3;
239 bcsp->txack_req = 0;
240 BT_DBG("We request packet no %u to card", bcsp->rxseq_txack);
241
242 if (rel) {
243 hdr[0] |= 0x80 + bcsp->msgq_txseq;
244 BT_DBG("Sending packet with seqno %u", bcsp->msgq_txseq);
245 bcsp->msgq_txseq = (bcsp->msgq_txseq + 1) & 0x07;
246 }
247
248 if (bcsp->use_crc)
249 hdr[0] |= 0x40;
250
251 hdr[1] = ((len << 4) & 0xff) | chan;
252 hdr[2] = len >> 4;
253 hdr[3] = ~(hdr[0] + hdr[1] + hdr[2]);
254
255 /* Put BCSP header */
256 for (i = 0; i < 4; i++) {
257 bcsp_slip_one_byte(nskb, hdr[i]);
258
259 if (bcsp->use_crc)
260 bcsp_crc_update(&bcsp_txmsg_crc, hdr[i]);
261 }
262
263 /* Put payload */
264 for (i = 0; i < len; i++) {
265 bcsp_slip_one_byte(nskb, data[i]);
266
267 if (bcsp->use_crc)
268 bcsp_crc_update(&bcsp_txmsg_crc, data[i]);
269 }
270
271 /* Put CRC */
272 if (bcsp->use_crc) {
273 bcsp_txmsg_crc = bitrev16(bcsp_txmsg_crc);
274 bcsp_slip_one_byte(nskb, (u8) ((bcsp_txmsg_crc >> 8) & 0x00ff));
275 bcsp_slip_one_byte(nskb, (u8) (bcsp_txmsg_crc & 0x00ff));
276 }
277
278 bcsp_slip_msgdelim(nskb);
279 return nskb;
280}
281
282/* This is a rewrite of pkt_avail in ABCSP */
283static struct sk_buff *bcsp_dequeue(struct hci_uart *hu)
284{
285 struct bcsp_struct *bcsp = hu->priv;
286 unsigned long flags;
287 struct sk_buff *skb;
288
289 /* First of all, check for unreliable messages in the queue,
290 since they have priority */
291
292 skb = skb_dequeue(&bcsp->unrel);
293 if (skb != NULL) {
294 struct sk_buff *nskb;
295
296 nskb = bcsp_prepare_pkt(bcsp, skb->data, skb->len,
297 hci_skb_pkt_type(skb));
298 if (nskb) {
299 kfree_skb(skb);
300 return nskb;
301 } else {
302 skb_queue_head(&bcsp->unrel, skb);
303 BT_ERR("Could not dequeue pkt because alloc_skb failed");
304 }
305 }
306
307 /* Now, try to send a reliable pkt. We can only send a
308 reliable packet if the number of packets sent but not yet ack'ed
309 is < than the winsize */
310
311 spin_lock_irqsave_nested(&bcsp->unack.lock, flags, SINGLE_DEPTH_NESTING);
312
313 if (bcsp->unack.qlen < BCSP_TXWINSIZE) {
314 skb = skb_dequeue(&bcsp->rel);
315 if (skb != NULL) {
316 struct sk_buff *nskb;
317
318 nskb = bcsp_prepare_pkt(bcsp, skb->data, skb->len,
319 hci_skb_pkt_type(skb));
320 if (nskb) {
321 __skb_queue_tail(&bcsp->unack, skb);
322 mod_timer(&bcsp->tbcsp, jiffies + HZ / 4);
323 spin_unlock_irqrestore(&bcsp->unack.lock, flags);
324 return nskb;
325 } else {
326 skb_queue_head(&bcsp->rel, skb);
327 BT_ERR("Could not dequeue pkt because alloc_skb failed");
328 }
329 }
330 }
331
332 spin_unlock_irqrestore(&bcsp->unack.lock, flags);
333
334 /* We could not send a reliable packet, either because there are
335 none or because there are too many unack'ed pkts. Did we receive
336 any packets we have not acknowledged yet ? */
337
338 if (bcsp->txack_req) {
339 /* if so, craft an empty ACK pkt and send it on BCSP unreliable
340 channel 0 */
341 struct sk_buff *nskb = bcsp_prepare_pkt(bcsp, NULL, 0, BCSP_ACK_PKT);
342 return nskb;
343 }
344
345 /* We have nothing to send */
346 return NULL;
347}
348
349static int bcsp_flush(struct hci_uart *hu)
350{
351 BT_DBG("hu %p", hu);
352 return 0;
353}
354
355/* Remove ack'ed packets */
356static void bcsp_pkt_cull(struct bcsp_struct *bcsp)
357{
358 struct sk_buff *skb, *tmp;
359 unsigned long flags;
360 int i, pkts_to_be_removed;
361 u8 seqno;
362
363 spin_lock_irqsave(&bcsp->unack.lock, flags);
364
365 pkts_to_be_removed = skb_queue_len(&bcsp->unack);
366 seqno = bcsp->msgq_txseq;
367
368 while (pkts_to_be_removed) {
369 if (bcsp->rxack == seqno)
370 break;
371 pkts_to_be_removed--;
372 seqno = (seqno - 1) & 0x07;
373 }
374
375 if (bcsp->rxack != seqno)
376 BT_ERR("Peer acked invalid packet");
377
378 BT_DBG("Removing %u pkts out of %u, up to seqno %u",
379 pkts_to_be_removed, skb_queue_len(&bcsp->unack),
380 (seqno - 1) & 0x07);
381
382 i = 0;
383 skb_queue_walk_safe(&bcsp->unack, skb, tmp) {
384 if (i >= pkts_to_be_removed)
385 break;
386 i++;
387
388 __skb_unlink(skb, &bcsp->unack);
389 kfree_skb(skb);
390 }
391
392 if (skb_queue_empty(&bcsp->unack))
393 del_timer(&bcsp->tbcsp);
394
395 spin_unlock_irqrestore(&bcsp->unack.lock, flags);
396
397 if (i != pkts_to_be_removed)
398 BT_ERR("Removed only %u out of %u pkts", i, pkts_to_be_removed);
399}
400
401/* Handle BCSP link-establishment packets. When we
402 detect a "sync" packet, symptom that the BT module has reset,
403 we do nothing :) (yet) */
404static void bcsp_handle_le_pkt(struct hci_uart *hu)
405{
406 struct bcsp_struct *bcsp = hu->priv;
407 u8 conf_pkt[4] = { 0xad, 0xef, 0xac, 0xed };
408 u8 conf_rsp_pkt[4] = { 0xde, 0xad, 0xd0, 0xd0 };
409 u8 sync_pkt[4] = { 0xda, 0xdc, 0xed, 0xed };
410
411 /* spot "conf" pkts and reply with a "conf rsp" pkt */
412 if (bcsp->rx_skb->data[1] >> 4 == 4 && bcsp->rx_skb->data[2] == 0 &&
413 !memcmp(&bcsp->rx_skb->data[4], conf_pkt, 4)) {
414 struct sk_buff *nskb = alloc_skb(4, GFP_ATOMIC);
415
416 BT_DBG("Found a LE conf pkt");
417 if (!nskb)
418 return;
419 memcpy(skb_put(nskb, 4), conf_rsp_pkt, 4);
420 hci_skb_pkt_type(nskb) = BCSP_LE_PKT;
421
422 skb_queue_head(&bcsp->unrel, nskb);
423 hci_uart_tx_wakeup(hu);
424 }
425 /* Spot "sync" pkts. If we find one...disaster! */
426 else if (bcsp->rx_skb->data[1] >> 4 == 4 && bcsp->rx_skb->data[2] == 0 &&
427 !memcmp(&bcsp->rx_skb->data[4], sync_pkt, 4)) {
428 BT_ERR("Found a LE sync pkt, card has reset");
429 }
430}
431
432static inline void bcsp_unslip_one_byte(struct bcsp_struct *bcsp, unsigned char byte)
433{
434 const u8 c0 = 0xc0, db = 0xdb;
435
436 switch (bcsp->rx_esc_state) {
437 case BCSP_ESCSTATE_NOESC:
438 switch (byte) {
439 case 0xdb:
440 bcsp->rx_esc_state = BCSP_ESCSTATE_ESC;
441 break;
442 default:
443 memcpy(skb_put(bcsp->rx_skb, 1), &byte, 1);
444 if ((bcsp->rx_skb->data[0] & 0x40) != 0 &&
445 bcsp->rx_state != BCSP_W4_CRC)
446 bcsp_crc_update(&bcsp->message_crc, byte);
447 bcsp->rx_count--;
448 }
449 break;
450
451 case BCSP_ESCSTATE_ESC:
452 switch (byte) {
453 case 0xdc:
454 memcpy(skb_put(bcsp->rx_skb, 1), &c0, 1);
455 if ((bcsp->rx_skb->data[0] & 0x40) != 0 &&
456 bcsp->rx_state != BCSP_W4_CRC)
457 bcsp_crc_update(&bcsp->message_crc, 0xc0);
458 bcsp->rx_esc_state = BCSP_ESCSTATE_NOESC;
459 bcsp->rx_count--;
460 break;
461
462 case 0xdd:
463 memcpy(skb_put(bcsp->rx_skb, 1), &db, 1);
464 if ((bcsp->rx_skb->data[0] & 0x40) != 0 &&
465 bcsp->rx_state != BCSP_W4_CRC)
466 bcsp_crc_update(&bcsp->message_crc, 0xdb);
467 bcsp->rx_esc_state = BCSP_ESCSTATE_NOESC;
468 bcsp->rx_count--;
469 break;
470
471 default:
472 BT_ERR("Invalid byte %02x after esc byte", byte);
473 kfree_skb(bcsp->rx_skb);
474 bcsp->rx_skb = NULL;
475 bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
476 bcsp->rx_count = 0;
477 }
478 }
479}
480
481static void bcsp_complete_rx_pkt(struct hci_uart *hu)
482{
483 struct bcsp_struct *bcsp = hu->priv;
484 int pass_up;
485
486 if (bcsp->rx_skb->data[0] & 0x80) { /* reliable pkt */
487 BT_DBG("Received seqno %u from card", bcsp->rxseq_txack);
488 bcsp->rxseq_txack++;
489 bcsp->rxseq_txack %= 0x8;
490 bcsp->txack_req = 1;
491
492 /* If needed, transmit an ack pkt */
493 hci_uart_tx_wakeup(hu);
494 }
495
496 bcsp->rxack = (bcsp->rx_skb->data[0] >> 3) & 0x07;
497 BT_DBG("Request for pkt %u from card", bcsp->rxack);
498
499 bcsp_pkt_cull(bcsp);
500 if ((bcsp->rx_skb->data[1] & 0x0f) == 6 &&
501 bcsp->rx_skb->data[0] & 0x80) {
502 hci_skb_pkt_type(bcsp->rx_skb) = HCI_ACLDATA_PKT;
503 pass_up = 1;
504 } else if ((bcsp->rx_skb->data[1] & 0x0f) == 5 &&
505 bcsp->rx_skb->data[0] & 0x80) {
506 hci_skb_pkt_type(bcsp->rx_skb) = HCI_EVENT_PKT;
507 pass_up = 1;
508 } else if ((bcsp->rx_skb->data[1] & 0x0f) == 7) {
509 hci_skb_pkt_type(bcsp->rx_skb) = HCI_SCODATA_PKT;
510 pass_up = 1;
511 } else if ((bcsp->rx_skb->data[1] & 0x0f) == 1 &&
512 !(bcsp->rx_skb->data[0] & 0x80)) {
513 bcsp_handle_le_pkt(hu);
514 pass_up = 0;
515 } else
516 pass_up = 0;
517
518 if (!pass_up) {
519 struct hci_event_hdr hdr;
520 u8 desc = (bcsp->rx_skb->data[1] & 0x0f);
521
522 if (desc != 0 && desc != 1) {
523 if (hciextn) {
524 desc |= 0xc0;
525 skb_pull(bcsp->rx_skb, 4);
526 memcpy(skb_push(bcsp->rx_skb, 1), &desc, 1);
527
528 hdr.evt = 0xff;
529 hdr.plen = bcsp->rx_skb->len;
530 memcpy(skb_push(bcsp->rx_skb, HCI_EVENT_HDR_SIZE), &hdr, HCI_EVENT_HDR_SIZE);
531 hci_skb_pkt_type(bcsp->rx_skb) = HCI_EVENT_PKT;
532
533 hci_recv_frame(hu->hdev, bcsp->rx_skb);
534 } else {
535 BT_ERR("Packet for unknown channel (%u %s)",
536 bcsp->rx_skb->data[1] & 0x0f,
537 bcsp->rx_skb->data[0] & 0x80 ?
538 "reliable" : "unreliable");
539 kfree_skb(bcsp->rx_skb);
540 }
541 } else
542 kfree_skb(bcsp->rx_skb);
543 } else {
544 /* Pull out BCSP hdr */
545 skb_pull(bcsp->rx_skb, 4);
546
547 hci_recv_frame(hu->hdev, bcsp->rx_skb);
548 }
549
550 bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
551 bcsp->rx_skb = NULL;
552}
553
554static u16 bscp_get_crc(struct bcsp_struct *bcsp)
555{
556 return get_unaligned_be16(&bcsp->rx_skb->data[bcsp->rx_skb->len - 2]);
557}
558
559/* Recv data */
560static int bcsp_recv(struct hci_uart *hu, const void *data, int count)
561{
562 struct bcsp_struct *bcsp = hu->priv;
563 const unsigned char *ptr;
564
565 BT_DBG("hu %p count %d rx_state %d rx_count %ld",
566 hu, count, bcsp->rx_state, bcsp->rx_count);
567
568 ptr = data;
569 while (count) {
570 if (bcsp->rx_count) {
571 if (*ptr == 0xc0) {
572 BT_ERR("Short BCSP packet");
573 kfree_skb(bcsp->rx_skb);
574 bcsp->rx_state = BCSP_W4_PKT_START;
575 bcsp->rx_count = 0;
576 } else
577 bcsp_unslip_one_byte(bcsp, *ptr);
578
579 ptr++; count--;
580 continue;
581 }
582
583 switch (bcsp->rx_state) {
584 case BCSP_W4_BCSP_HDR:
585 if ((0xff & (u8) ~ (bcsp->rx_skb->data[0] + bcsp->rx_skb->data[1] +
586 bcsp->rx_skb->data[2])) != bcsp->rx_skb->data[3]) {
587 BT_ERR("Error in BCSP hdr checksum");
588 kfree_skb(bcsp->rx_skb);
589 bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
590 bcsp->rx_count = 0;
591 continue;
592 }
593 if (bcsp->rx_skb->data[0] & 0x80 /* reliable pkt */
594 && (bcsp->rx_skb->data[0] & 0x07) != bcsp->rxseq_txack) {
595 BT_ERR("Out-of-order packet arrived, got %u expected %u",
596 bcsp->rx_skb->data[0] & 0x07, bcsp->rxseq_txack);
597
598 kfree_skb(bcsp->rx_skb);
599 bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
600 bcsp->rx_count = 0;
601 continue;
602 }
603 bcsp->rx_state = BCSP_W4_DATA;
604 bcsp->rx_count = (bcsp->rx_skb->data[1] >> 4) +
605 (bcsp->rx_skb->data[2] << 4); /* May be 0 */
606 continue;
607
608 case BCSP_W4_DATA:
609 if (bcsp->rx_skb->data[0] & 0x40) { /* pkt with crc */
610 bcsp->rx_state = BCSP_W4_CRC;
611 bcsp->rx_count = 2;
612 } else
613 bcsp_complete_rx_pkt(hu);
614 continue;
615
616 case BCSP_W4_CRC:
617 if (bitrev16(bcsp->message_crc) != bscp_get_crc(bcsp)) {
618 BT_ERR ("Checksum failed: computed %04x received %04x",
619 bitrev16(bcsp->message_crc),
620 bscp_get_crc(bcsp));
621
622 kfree_skb(bcsp->rx_skb);
623 bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
624 bcsp->rx_count = 0;
625 continue;
626 }
627 skb_trim(bcsp->rx_skb, bcsp->rx_skb->len - 2);
628 bcsp_complete_rx_pkt(hu);
629 continue;
630
631 case BCSP_W4_PKT_DELIMITER:
632 switch (*ptr) {
633 case 0xc0:
634 bcsp->rx_state = BCSP_W4_PKT_START;
635 break;
636 default:
637 /*BT_ERR("Ignoring byte %02x", *ptr);*/
638 break;
639 }
640 ptr++; count--;
641 break;
642
643 case BCSP_W4_PKT_START:
644 switch (*ptr) {
645 case 0xc0:
646 ptr++; count--;
647 break;
648
649 default:
650 bcsp->rx_state = BCSP_W4_BCSP_HDR;
651 bcsp->rx_count = 4;
652 bcsp->rx_esc_state = BCSP_ESCSTATE_NOESC;
653 BCSP_CRC_INIT(bcsp->message_crc);
654
655 /* Do not increment ptr or decrement count
656 * Allocate packet. Max len of a BCSP pkt=
657 * 0xFFF (payload) +4 (header) +2 (crc) */
658
659 bcsp->rx_skb = bt_skb_alloc(0x1005, GFP_ATOMIC);
660 if (!bcsp->rx_skb) {
661 BT_ERR("Can't allocate mem for new packet");
662 bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
663 bcsp->rx_count = 0;
664 return 0;
665 }
666 break;
667 }
668 break;
669 }
670 }
671 return count;
672}
673
674 /* Arrange to retransmit all messages in the relq. */
675static void bcsp_timed_event(unsigned long arg)
676{
677 struct hci_uart *hu = (struct hci_uart *) arg;
678 struct bcsp_struct *bcsp = hu->priv;
679 struct sk_buff *skb;
680 unsigned long flags;
681
682 BT_DBG("hu %p retransmitting %u pkts", hu, bcsp->unack.qlen);
683
684 spin_lock_irqsave_nested(&bcsp->unack.lock, flags, SINGLE_DEPTH_NESTING);
685
686 while ((skb = __skb_dequeue_tail(&bcsp->unack)) != NULL) {
687 bcsp->msgq_txseq = (bcsp->msgq_txseq - 1) & 0x07;
688 skb_queue_head(&bcsp->rel, skb);
689 }
690
691 spin_unlock_irqrestore(&bcsp->unack.lock, flags);
692
693 hci_uart_tx_wakeup(hu);
694}
695
696static int bcsp_open(struct hci_uart *hu)
697{
698 struct bcsp_struct *bcsp;
699
700 BT_DBG("hu %p", hu);
701
702 bcsp = kzalloc(sizeof(*bcsp), GFP_KERNEL);
703 if (!bcsp)
704 return -ENOMEM;
705
706 hu->priv = bcsp;
707 skb_queue_head_init(&bcsp->unack);
708 skb_queue_head_init(&bcsp->rel);
709 skb_queue_head_init(&bcsp->unrel);
710
711 init_timer(&bcsp->tbcsp);
712 bcsp->tbcsp.function = bcsp_timed_event;
713 bcsp->tbcsp.data = (u_long) hu;
714
715 bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
716
717 if (txcrc)
718 bcsp->use_crc = 1;
719
720 return 0;
721}
722
723static int bcsp_close(struct hci_uart *hu)
724{
725 struct bcsp_struct *bcsp = hu->priv;
726
727 del_timer_sync(&bcsp->tbcsp);
728
729 hu->priv = NULL;
730
731 BT_DBG("hu %p", hu);
732
733 skb_queue_purge(&bcsp->unack);
734 skb_queue_purge(&bcsp->rel);
735 skb_queue_purge(&bcsp->unrel);
736
737 kfree(bcsp);
738 return 0;
739}
740
741static const struct hci_uart_proto bcsp = {
742 .id = HCI_UART_BCSP,
743 .name = "BCSP",
744 .open = bcsp_open,
745 .close = bcsp_close,
746 .enqueue = bcsp_enqueue,
747 .dequeue = bcsp_dequeue,
748 .recv = bcsp_recv,
749 .flush = bcsp_flush
750};
751
752int __init bcsp_init(void)
753{
754 return hci_uart_register_proto(&bcsp);
755}
756
757int __exit bcsp_deinit(void)
758{
759 return hci_uart_unregister_proto(&bcsp);
760}
761
762module_param(txcrc, bool, 0644);
763MODULE_PARM_DESC(txcrc, "Transmit CRC with every BCSP packet");
764
765module_param(hciextn, bool, 0644);
766MODULE_PARM_DESC(hciextn, "Convert HCI Extensions into BCSP packets");