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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,
93 * initial value 0xffff, bits shifted in reverse order.
94 */
95
96static const u16 crc_table[] = {
97 0x0000, 0x1081, 0x2102, 0x3183,
98 0x4204, 0x5285, 0x6306, 0x7387,
99 0x8408, 0x9489, 0xa50a, 0xb58b,
100 0xc60c, 0xd68d, 0xe70e, 0xf78f
101};
102
103/* Initialise the crc calculator */
104#define BCSP_CRC_INIT(x) x = 0xffff
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
218 if ((desc & 0xf0) == 0xc0) {
219 data += HCI_COMMAND_HDR_SIZE + 1;
220 len -= HCI_COMMAND_HDR_SIZE + 1;
221 chan = desc & 0x0f;
222 }
223 }
224 }
225
226 /* Max len of packet: (original len +4(bcsp hdr) +2(crc))*2
227 * (because bytes 0xc0 and 0xdb are escaped, worst case is
228 * when the packet is all made of 0xc0 and 0xdb :) )
229 * + 2 (0xc0 delimiters at start and end).
230 */
231
232 nskb = alloc_skb((len + 6) * 2 + 2, GFP_ATOMIC);
233 if (!nskb)
234 return NULL;
235
236 hci_skb_pkt_type(nskb) = 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
295 skb = skb_dequeue(&bcsp->unrel);
296 if (skb != NULL) {
297 struct sk_buff *nskb;
298
299 nskb = bcsp_prepare_pkt(bcsp, skb->data, skb->len,
300 hci_skb_pkt_type(skb));
301 if (nskb) {
302 kfree_skb(skb);
303 return nskb;
304 } else {
305 skb_queue_head(&bcsp->unrel, skb);
306 BT_ERR("Could not dequeue pkt because alloc_skb failed");
307 }
308 }
309
310 /* Now, try to send a reliable pkt. We can only send a
311 * reliable packet if the number of packets sent but not yet ack'ed
312 * is < than the winsize
313 */
314
315 spin_lock_irqsave_nested(&bcsp->unack.lock, flags, SINGLE_DEPTH_NESTING);
316
317 if (bcsp->unack.qlen < BCSP_TXWINSIZE) {
318 skb = skb_dequeue(&bcsp->rel);
319 if (skb != NULL) {
320 struct sk_buff *nskb;
321
322 nskb = bcsp_prepare_pkt(bcsp, skb->data, skb->len,
323 hci_skb_pkt_type(skb));
324 if (nskb) {
325 __skb_queue_tail(&bcsp->unack, skb);
326 mod_timer(&bcsp->tbcsp, jiffies + HZ / 4);
327 spin_unlock_irqrestore(&bcsp->unack.lock, flags);
328 return nskb;
329 } else {
330 skb_queue_head(&bcsp->rel, skb);
331 BT_ERR("Could not dequeue pkt because alloc_skb failed");
332 }
333 }
334 }
335
336 spin_unlock_irqrestore(&bcsp->unack.lock, flags);
337
338 /* We could not send a reliable packet, either because there are
339 * none or because there are too many unack'ed pkts. Did we receive
340 * any packets we have not acknowledged yet ?
341 */
342
343 if (bcsp->txack_req) {
344 /* if so, craft an empty ACK pkt and send it on BCSP unreliable
345 * channel 0
346 */
347 struct sk_buff *nskb = bcsp_prepare_pkt(bcsp, NULL, 0, BCSP_ACK_PKT);
348 return nskb;
349 }
350
351 /* We have nothing to send */
352 return NULL;
353}
354
355static int bcsp_flush(struct hci_uart *hu)
356{
357 BT_DBG("hu %p", hu);
358 return 0;
359}
360
361/* Remove ack'ed packets */
362static void bcsp_pkt_cull(struct bcsp_struct *bcsp)
363{
364 struct sk_buff *skb, *tmp;
365 unsigned long flags;
366 int i, pkts_to_be_removed;
367 u8 seqno;
368
369 spin_lock_irqsave(&bcsp->unack.lock, flags);
370
371 pkts_to_be_removed = skb_queue_len(&bcsp->unack);
372 seqno = bcsp->msgq_txseq;
373
374 while (pkts_to_be_removed) {
375 if (bcsp->rxack == seqno)
376 break;
377 pkts_to_be_removed--;
378 seqno = (seqno - 1) & 0x07;
379 }
380
381 if (bcsp->rxack != seqno)
382 BT_ERR("Peer acked invalid packet");
383
384 BT_DBG("Removing %u pkts out of %u, up to seqno %u",
385 pkts_to_be_removed, skb_queue_len(&bcsp->unack),
386 (seqno - 1) & 0x07);
387
388 i = 0;
389 skb_queue_walk_safe(&bcsp->unack, skb, tmp) {
390 if (i >= pkts_to_be_removed)
391 break;
392 i++;
393
394 __skb_unlink(skb, &bcsp->unack);
395 kfree_skb(skb);
396 }
397
398 if (skb_queue_empty(&bcsp->unack))
399 del_timer(&bcsp->tbcsp);
400
401 spin_unlock_irqrestore(&bcsp->unack.lock, flags);
402
403 if (i != pkts_to_be_removed)
404 BT_ERR("Removed only %u out of %u pkts", i, pkts_to_be_removed);
405}
406
407/* Handle BCSP link-establishment packets. When we
408 * detect a "sync" packet, symptom that the BT module has reset,
409 * we do nothing :) (yet)
410 */
411static void bcsp_handle_le_pkt(struct hci_uart *hu)
412{
413 struct bcsp_struct *bcsp = hu->priv;
414 u8 conf_pkt[4] = { 0xad, 0xef, 0xac, 0xed };
415 u8 conf_rsp_pkt[4] = { 0xde, 0xad, 0xd0, 0xd0 };
416 u8 sync_pkt[4] = { 0xda, 0xdc, 0xed, 0xed };
417
418 /* spot "conf" pkts and reply with a "conf rsp" pkt */
419 if (bcsp->rx_skb->data[1] >> 4 == 4 && bcsp->rx_skb->data[2] == 0 &&
420 !memcmp(&bcsp->rx_skb->data[4], conf_pkt, 4)) {
421 struct sk_buff *nskb = alloc_skb(4, GFP_ATOMIC);
422
423 BT_DBG("Found a LE conf pkt");
424 if (!nskb)
425 return;
426 memcpy(skb_put(nskb, 4), conf_rsp_pkt, 4);
427 hci_skb_pkt_type(nskb) = BCSP_LE_PKT;
428
429 skb_queue_head(&bcsp->unrel, nskb);
430 hci_uart_tx_wakeup(hu);
431 }
432 /* Spot "sync" pkts. If we find one...disaster! */
433 else if (bcsp->rx_skb->data[1] >> 4 == 4 && bcsp->rx_skb->data[2] == 0 &&
434 !memcmp(&bcsp->rx_skb->data[4], sync_pkt, 4)) {
435 BT_ERR("Found a LE sync pkt, card has reset");
436 }
437}
438
439static inline void bcsp_unslip_one_byte(struct bcsp_struct *bcsp, unsigned char byte)
440{
441 const u8 c0 = 0xc0, db = 0xdb;
442
443 switch (bcsp->rx_esc_state) {
444 case BCSP_ESCSTATE_NOESC:
445 switch (byte) {
446 case 0xdb:
447 bcsp->rx_esc_state = BCSP_ESCSTATE_ESC;
448 break;
449 default:
450 memcpy(skb_put(bcsp->rx_skb, 1), &byte, 1);
451 if ((bcsp->rx_skb->data[0] & 0x40) != 0 &&
452 bcsp->rx_state != BCSP_W4_CRC)
453 bcsp_crc_update(&bcsp->message_crc, byte);
454 bcsp->rx_count--;
455 }
456 break;
457
458 case BCSP_ESCSTATE_ESC:
459 switch (byte) {
460 case 0xdc:
461 memcpy(skb_put(bcsp->rx_skb, 1), &c0, 1);
462 if ((bcsp->rx_skb->data[0] & 0x40) != 0 &&
463 bcsp->rx_state != BCSP_W4_CRC)
464 bcsp_crc_update(&bcsp->message_crc, 0xc0);
465 bcsp->rx_esc_state = BCSP_ESCSTATE_NOESC;
466 bcsp->rx_count--;
467 break;
468
469 case 0xdd:
470 memcpy(skb_put(bcsp->rx_skb, 1), &db, 1);
471 if ((bcsp->rx_skb->data[0] & 0x40) != 0 &&
472 bcsp->rx_state != BCSP_W4_CRC)
473 bcsp_crc_update(&bcsp->message_crc, 0xdb);
474 bcsp->rx_esc_state = BCSP_ESCSTATE_NOESC;
475 bcsp->rx_count--;
476 break;
477
478 default:
479 BT_ERR("Invalid byte %02x after esc byte", byte);
480 kfree_skb(bcsp->rx_skb);
481 bcsp->rx_skb = NULL;
482 bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
483 bcsp->rx_count = 0;
484 }
485 }
486}
487
488static void bcsp_complete_rx_pkt(struct hci_uart *hu)
489{
490 struct bcsp_struct *bcsp = hu->priv;
491 int pass_up = 0;
492
493 if (bcsp->rx_skb->data[0] & 0x80) { /* reliable pkt */
494 BT_DBG("Received seqno %u from card", bcsp->rxseq_txack);
495
496 /* check the rx sequence number is as expected */
497 if ((bcsp->rx_skb->data[0] & 0x07) == bcsp->rxseq_txack) {
498 bcsp->rxseq_txack++;
499 bcsp->rxseq_txack %= 0x8;
500 } else {
501 /* handle re-transmitted packet or
502 * when packet was missed
503 */
504 BT_ERR("Out-of-order packet arrived, got %u expected %u",
505 bcsp->rx_skb->data[0] & 0x07, bcsp->rxseq_txack);
506
507 /* do not process out-of-order packet payload */
508 pass_up = 2;
509 }
510
511 /* send current txack value to all received reliable packets */
512 bcsp->txack_req = 1;
513
514 /* If needed, transmit an ack pkt */
515 hci_uart_tx_wakeup(hu);
516 }
517
518 bcsp->rxack = (bcsp->rx_skb->data[0] >> 3) & 0x07;
519 BT_DBG("Request for pkt %u from card", bcsp->rxack);
520
521 /* handle received ACK indications,
522 * including those from out-of-order packets
523 */
524 bcsp_pkt_cull(bcsp);
525
526 if (pass_up != 2) {
527 if ((bcsp->rx_skb->data[1] & 0x0f) == 6 &&
528 (bcsp->rx_skb->data[0] & 0x80)) {
529 hci_skb_pkt_type(bcsp->rx_skb) = HCI_ACLDATA_PKT;
530 pass_up = 1;
531 } else if ((bcsp->rx_skb->data[1] & 0x0f) == 5 &&
532 (bcsp->rx_skb->data[0] & 0x80)) {
533 hci_skb_pkt_type(bcsp->rx_skb) = HCI_EVENT_PKT;
534 pass_up = 1;
535 } else if ((bcsp->rx_skb->data[1] & 0x0f) == 7) {
536 hci_skb_pkt_type(bcsp->rx_skb) = HCI_SCODATA_PKT;
537 pass_up = 1;
538 } else if ((bcsp->rx_skb->data[1] & 0x0f) == 1 &&
539 !(bcsp->rx_skb->data[0] & 0x80)) {
540 bcsp_handle_le_pkt(hu);
541 pass_up = 0;
542 } else {
543 pass_up = 0;
544 }
545 }
546
547 if (pass_up == 0) {
548 struct hci_event_hdr hdr;
549 u8 desc = (bcsp->rx_skb->data[1] & 0x0f);
550
551 if (desc != 0 && desc != 1) {
552 if (hciextn) {
553 desc |= 0xc0;
554 skb_pull(bcsp->rx_skb, 4);
555 memcpy(skb_push(bcsp->rx_skb, 1), &desc, 1);
556
557 hdr.evt = 0xff;
558 hdr.plen = bcsp->rx_skb->len;
559 memcpy(skb_push(bcsp->rx_skb, HCI_EVENT_HDR_SIZE), &hdr, HCI_EVENT_HDR_SIZE);
560 hci_skb_pkt_type(bcsp->rx_skb) = HCI_EVENT_PKT;
561
562 hci_recv_frame(hu->hdev, bcsp->rx_skb);
563 } else {
564 BT_ERR("Packet for unknown channel (%u %s)",
565 bcsp->rx_skb->data[1] & 0x0f,
566 bcsp->rx_skb->data[0] & 0x80 ?
567 "reliable" : "unreliable");
568 kfree_skb(bcsp->rx_skb);
569 }
570 } else
571 kfree_skb(bcsp->rx_skb);
572 } else if (pass_up == 1) {
573 /* Pull out BCSP hdr */
574 skb_pull(bcsp->rx_skb, 4);
575
576 hci_recv_frame(hu->hdev, bcsp->rx_skb);
577 } else {
578 /* ignore packet payload of already ACKed re-transmitted
579 * packets or when a packet was missed in the BCSP window
580 */
581 kfree_skb(bcsp->rx_skb);
582 }
583
584 bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
585 bcsp->rx_skb = NULL;
586}
587
588static u16 bscp_get_crc(struct bcsp_struct *bcsp)
589{
590 return get_unaligned_be16(&bcsp->rx_skb->data[bcsp->rx_skb->len - 2]);
591}
592
593/* Recv data */
594static int bcsp_recv(struct hci_uart *hu, const void *data, int count)
595{
596 struct bcsp_struct *bcsp = hu->priv;
597 const unsigned char *ptr;
598
599 BT_DBG("hu %p count %d rx_state %d rx_count %ld",
600 hu, count, bcsp->rx_state, bcsp->rx_count);
601
602 ptr = data;
603 while (count) {
604 if (bcsp->rx_count) {
605 if (*ptr == 0xc0) {
606 BT_ERR("Short BCSP packet");
607 kfree_skb(bcsp->rx_skb);
608 bcsp->rx_state = BCSP_W4_PKT_START;
609 bcsp->rx_count = 0;
610 } else
611 bcsp_unslip_one_byte(bcsp, *ptr);
612
613 ptr++; count--;
614 continue;
615 }
616
617 switch (bcsp->rx_state) {
618 case BCSP_W4_BCSP_HDR:
619 if ((0xff & (u8)~(bcsp->rx_skb->data[0] + bcsp->rx_skb->data[1] +
620 bcsp->rx_skb->data[2])) != bcsp->rx_skb->data[3]) {
621 BT_ERR("Error in BCSP hdr checksum");
622 kfree_skb(bcsp->rx_skb);
623 bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
624 bcsp->rx_count = 0;
625 continue;
626 }
627 bcsp->rx_state = BCSP_W4_DATA;
628 bcsp->rx_count = (bcsp->rx_skb->data[1] >> 4) +
629 (bcsp->rx_skb->data[2] << 4); /* May be 0 */
630 continue;
631
632 case BCSP_W4_DATA:
633 if (bcsp->rx_skb->data[0] & 0x40) { /* pkt with crc */
634 bcsp->rx_state = BCSP_W4_CRC;
635 bcsp->rx_count = 2;
636 } else
637 bcsp_complete_rx_pkt(hu);
638 continue;
639
640 case BCSP_W4_CRC:
641 if (bitrev16(bcsp->message_crc) != bscp_get_crc(bcsp)) {
642 BT_ERR("Checksum failed: computed %04x received %04x",
643 bitrev16(bcsp->message_crc),
644 bscp_get_crc(bcsp));
645
646 kfree_skb(bcsp->rx_skb);
647 bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
648 bcsp->rx_count = 0;
649 continue;
650 }
651 skb_trim(bcsp->rx_skb, bcsp->rx_skb->len - 2);
652 bcsp_complete_rx_pkt(hu);
653 continue;
654
655 case BCSP_W4_PKT_DELIMITER:
656 switch (*ptr) {
657 case 0xc0:
658 bcsp->rx_state = BCSP_W4_PKT_START;
659 break;
660 default:
661 /*BT_ERR("Ignoring byte %02x", *ptr);*/
662 break;
663 }
664 ptr++; count--;
665 break;
666
667 case BCSP_W4_PKT_START:
668 switch (*ptr) {
669 case 0xc0:
670 ptr++; count--;
671 break;
672
673 default:
674 bcsp->rx_state = BCSP_W4_BCSP_HDR;
675 bcsp->rx_count = 4;
676 bcsp->rx_esc_state = BCSP_ESCSTATE_NOESC;
677 BCSP_CRC_INIT(bcsp->message_crc);
678
679 /* Do not increment ptr or decrement count
680 * Allocate packet. Max len of a BCSP pkt=
681 * 0xFFF (payload) +4 (header) +2 (crc)
682 */
683
684 bcsp->rx_skb = bt_skb_alloc(0x1005, GFP_ATOMIC);
685 if (!bcsp->rx_skb) {
686 BT_ERR("Can't allocate mem for new packet");
687 bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
688 bcsp->rx_count = 0;
689 return 0;
690 }
691 break;
692 }
693 break;
694 }
695 }
696 return count;
697}
698
699 /* Arrange to retransmit all messages in the relq. */
700static void bcsp_timed_event(unsigned long arg)
701{
702 struct hci_uart *hu = (struct hci_uart *)arg;
703 struct bcsp_struct *bcsp = hu->priv;
704 struct sk_buff *skb;
705 unsigned long flags;
706
707 BT_DBG("hu %p retransmitting %u pkts", hu, bcsp->unack.qlen);
708
709 spin_lock_irqsave_nested(&bcsp->unack.lock, flags, SINGLE_DEPTH_NESTING);
710
711 while ((skb = __skb_dequeue_tail(&bcsp->unack)) != NULL) {
712 bcsp->msgq_txseq = (bcsp->msgq_txseq - 1) & 0x07;
713 skb_queue_head(&bcsp->rel, skb);
714 }
715
716 spin_unlock_irqrestore(&bcsp->unack.lock, flags);
717
718 hci_uart_tx_wakeup(hu);
719}
720
721static int bcsp_open(struct hci_uart *hu)
722{
723 struct bcsp_struct *bcsp;
724
725 BT_DBG("hu %p", hu);
726
727 bcsp = kzalloc(sizeof(*bcsp), GFP_KERNEL);
728 if (!bcsp)
729 return -ENOMEM;
730
731 hu->priv = bcsp;
732 skb_queue_head_init(&bcsp->unack);
733 skb_queue_head_init(&bcsp->rel);
734 skb_queue_head_init(&bcsp->unrel);
735
736 setup_timer(&bcsp->tbcsp, bcsp_timed_event, (u_long)hu);
737
738 bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
739
740 if (txcrc)
741 bcsp->use_crc = 1;
742
743 return 0;
744}
745
746static int bcsp_close(struct hci_uart *hu)
747{
748 struct bcsp_struct *bcsp = hu->priv;
749
750 del_timer_sync(&bcsp->tbcsp);
751
752 hu->priv = NULL;
753
754 BT_DBG("hu %p", hu);
755
756 skb_queue_purge(&bcsp->unack);
757 skb_queue_purge(&bcsp->rel);
758 skb_queue_purge(&bcsp->unrel);
759
760 kfree(bcsp);
761 return 0;
762}
763
764static const struct hci_uart_proto bcsp = {
765 .id = HCI_UART_BCSP,
766 .name = "BCSP",
767 .open = bcsp_open,
768 .close = bcsp_close,
769 .enqueue = bcsp_enqueue,
770 .dequeue = bcsp_dequeue,
771 .recv = bcsp_recv,
772 .flush = bcsp_flush
773};
774
775int __init bcsp_init(void)
776{
777 return hci_uart_register_proto(&bcsp);
778}
779
780int __exit bcsp_deinit(void)
781{
782 return hci_uart_unregister_proto(&bcsp);
783}
784
785module_param(txcrc, bool, 0644);
786MODULE_PARM_DESC(txcrc, "Transmit CRC with every BCSP packet");
787
788module_param(hciextn, bool, 0644);
789MODULE_PARM_DESC(hciextn, "Convert HCI Extensions into BCSP packets");