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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// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *
4 * Bluetooth HCI UART driver
5 *
6 * Copyright (C) 2002-2003 Fabrizio Gennari <fabrizio.gennari@philips.com>
7 * Copyright (C) 2004-2005 Marcel Holtmann <marcel@holtmann.org>
8 */
9
10#include <linux/module.h>
11
12#include <linux/kernel.h>
13#include <linux/init.h>
14#include <linux/types.h>
15#include <linux/fcntl.h>
16#include <linux/interrupt.h>
17#include <linux/ptrace.h>
18#include <linux/poll.h>
19
20#include <linux/slab.h>
21#include <linux/tty.h>
22#include <linux/errno.h>
23#include <linux/string.h>
24#include <linux/signal.h>
25#include <linux/ioctl.h>
26#include <linux/skbuff.h>
27#include <linux/bitrev.h>
28#include <asm/unaligned.h>
29
30#include <net/bluetooth/bluetooth.h>
31#include <net/bluetooth/hci_core.h>
32
33#include "hci_uart.h"
34
35static bool txcrc = true;
36static bool hciextn = true;
37
38#define BCSP_TXWINSIZE 4
39
40#define BCSP_ACK_PKT 0x05
41#define BCSP_LE_PKT 0x06
42
43struct bcsp_struct {
44 struct sk_buff_head unack; /* Unack'ed packets queue */
45 struct sk_buff_head rel; /* Reliable packets queue */
46 struct sk_buff_head unrel; /* Unreliable packets queue */
47
48 unsigned long rx_count;
49 struct sk_buff *rx_skb;
50 u8 rxseq_txack; /* rxseq == txack. */
51 u8 rxack; /* Last packet sent by us that the peer ack'ed */
52 struct timer_list tbcsp;
53 struct hci_uart *hu;
54
55 enum {
56 BCSP_W4_PKT_DELIMITER,
57 BCSP_W4_PKT_START,
58 BCSP_W4_BCSP_HDR,
59 BCSP_W4_DATA,
60 BCSP_W4_CRC
61 } rx_state;
62
63 enum {
64 BCSP_ESCSTATE_NOESC,
65 BCSP_ESCSTATE_ESC
66 } rx_esc_state;
67
68 u8 use_crc;
69 u16 message_crc;
70 u8 txack_req; /* Do we need to send ack's to the peer? */
71
72 /* Reliable packet sequence number - used to assign seq to each rel pkt. */
73 u8 msgq_txseq;
74};
75
76/* ---- BCSP CRC calculation ---- */
77
78/* Table for calculating CRC for polynomial 0x1021, LSB processed first,
79 * initial value 0xffff, bits shifted in reverse order.
80 */
81
82static const u16 crc_table[] = {
83 0x0000, 0x1081, 0x2102, 0x3183,
84 0x4204, 0x5285, 0x6306, 0x7387,
85 0x8408, 0x9489, 0xa50a, 0xb58b,
86 0xc60c, 0xd68d, 0xe70e, 0xf78f
87};
88
89/* Initialise the crc calculator */
90#define BCSP_CRC_INIT(x) x = 0xffff
91
92/* Update crc with next data byte
93 *
94 * Implementation note
95 * The data byte is treated as two nibbles. The crc is generated
96 * in reverse, i.e., bits are fed into the register from the top.
97 */
98static void bcsp_crc_update(u16 *crc, u8 d)
99{
100 u16 reg = *crc;
101
102 reg = (reg >> 4) ^ crc_table[(reg ^ d) & 0x000f];
103 reg = (reg >> 4) ^ crc_table[(reg ^ (d >> 4)) & 0x000f];
104
105 *crc = reg;
106}
107
108/* ---- BCSP core ---- */
109
110static void bcsp_slip_msgdelim(struct sk_buff *skb)
111{
112 const char pkt_delim = 0xc0;
113
114 skb_put_data(skb, &pkt_delim, 1);
115}
116
117static void bcsp_slip_one_byte(struct sk_buff *skb, u8 c)
118{
119 const char esc_c0[2] = { 0xdb, 0xdc };
120 const char esc_db[2] = { 0xdb, 0xdd };
121
122 switch (c) {
123 case 0xc0:
124 skb_put_data(skb, &esc_c0, 2);
125 break;
126 case 0xdb:
127 skb_put_data(skb, &esc_db, 2);
128 break;
129 default:
130 skb_put_data(skb, &c, 1);
131 }
132}
133
134static int bcsp_enqueue(struct hci_uart *hu, struct sk_buff *skb)
135{
136 struct bcsp_struct *bcsp = hu->priv;
137
138 if (skb->len > 0xFFF) {
139 BT_ERR("Packet too long");
140 kfree_skb(skb);
141 return 0;
142 }
143
144 switch (hci_skb_pkt_type(skb)) {
145 case HCI_ACLDATA_PKT:
146 case HCI_COMMAND_PKT:
147 skb_queue_tail(&bcsp->rel, skb);
148 break;
149
150 case HCI_SCODATA_PKT:
151 skb_queue_tail(&bcsp->unrel, skb);
152 break;
153
154 default:
155 BT_ERR("Unknown packet type");
156 kfree_skb(skb);
157 break;
158 }
159
160 return 0;
161}
162
163static struct sk_buff *bcsp_prepare_pkt(struct bcsp_struct *bcsp, u8 *data,
164 int len, int pkt_type)
165{
166 struct sk_buff *nskb;
167 u8 hdr[4], chan;
168 u16 BCSP_CRC_INIT(bcsp_txmsg_crc);
169 int rel, i;
170
171 switch (pkt_type) {
172 case HCI_ACLDATA_PKT:
173 chan = 6; /* BCSP ACL channel */
174 rel = 1; /* reliable channel */
175 break;
176 case HCI_COMMAND_PKT:
177 chan = 5; /* BCSP cmd/evt channel */
178 rel = 1; /* reliable channel */
179 break;
180 case HCI_SCODATA_PKT:
181 chan = 7; /* BCSP SCO channel */
182 rel = 0; /* unreliable channel */
183 break;
184 case BCSP_LE_PKT:
185 chan = 1; /* BCSP LE channel */
186 rel = 0; /* unreliable channel */
187 break;
188 case BCSP_ACK_PKT:
189 chan = 0; /* BCSP internal channel */
190 rel = 0; /* unreliable channel */
191 break;
192 default:
193 BT_ERR("Unknown packet type");
194 return NULL;
195 }
196
197 if (hciextn && chan == 5) {
198 __le16 opcode = ((struct hci_command_hdr *)data)->opcode;
199
200 /* Vendor specific commands */
201 if (hci_opcode_ogf(__le16_to_cpu(opcode)) == 0x3f) {
202 u8 desc = *(data + HCI_COMMAND_HDR_SIZE);
203
204 if ((desc & 0xf0) == 0xc0) {
205 data += HCI_COMMAND_HDR_SIZE + 1;
206 len -= HCI_COMMAND_HDR_SIZE + 1;
207 chan = desc & 0x0f;
208 }
209 }
210 }
211
212 /* Max len of packet: (original len +4(bcsp hdr) +2(crc))*2
213 * (because bytes 0xc0 and 0xdb are escaped, worst case is
214 * when the packet is all made of 0xc0 and 0xdb :) )
215 * + 2 (0xc0 delimiters at start and end).
216 */
217
218 nskb = alloc_skb((len + 6) * 2 + 2, GFP_ATOMIC);
219 if (!nskb)
220 return NULL;
221
222 hci_skb_pkt_type(nskb) = pkt_type;
223
224 bcsp_slip_msgdelim(nskb);
225
226 hdr[0] = bcsp->rxseq_txack << 3;
227 bcsp->txack_req = 0;
228 BT_DBG("We request packet no %u to card", bcsp->rxseq_txack);
229
230 if (rel) {
231 hdr[0] |= 0x80 + bcsp->msgq_txseq;
232 BT_DBG("Sending packet with seqno %u", bcsp->msgq_txseq);
233 bcsp->msgq_txseq = (bcsp->msgq_txseq + 1) & 0x07;
234 }
235
236 if (bcsp->use_crc)
237 hdr[0] |= 0x40;
238
239 hdr[1] = ((len << 4) & 0xff) | chan;
240 hdr[2] = len >> 4;
241 hdr[3] = ~(hdr[0] + hdr[1] + hdr[2]);
242
243 /* Put BCSP header */
244 for (i = 0; i < 4; i++) {
245 bcsp_slip_one_byte(nskb, hdr[i]);
246
247 if (bcsp->use_crc)
248 bcsp_crc_update(&bcsp_txmsg_crc, hdr[i]);
249 }
250
251 /* Put payload */
252 for (i = 0; i < len; i++) {
253 bcsp_slip_one_byte(nskb, data[i]);
254
255 if (bcsp->use_crc)
256 bcsp_crc_update(&bcsp_txmsg_crc, data[i]);
257 }
258
259 /* Put CRC */
260 if (bcsp->use_crc) {
261 bcsp_txmsg_crc = bitrev16(bcsp_txmsg_crc);
262 bcsp_slip_one_byte(nskb, (u8)((bcsp_txmsg_crc >> 8) & 0x00ff));
263 bcsp_slip_one_byte(nskb, (u8)(bcsp_txmsg_crc & 0x00ff));
264 }
265
266 bcsp_slip_msgdelim(nskb);
267 return nskb;
268}
269
270/* This is a rewrite of pkt_avail in ABCSP */
271static struct sk_buff *bcsp_dequeue(struct hci_uart *hu)
272{
273 struct bcsp_struct *bcsp = hu->priv;
274 unsigned long flags;
275 struct sk_buff *skb;
276
277 /* First of all, check for unreliable messages in the queue,
278 * since they have priority
279 */
280
281 skb = skb_dequeue(&bcsp->unrel);
282 if (skb != NULL) {
283 struct sk_buff *nskb;
284
285 nskb = bcsp_prepare_pkt(bcsp, skb->data, skb->len,
286 hci_skb_pkt_type(skb));
287 if (nskb) {
288 kfree_skb(skb);
289 return nskb;
290 } else {
291 skb_queue_head(&bcsp->unrel, skb);
292 BT_ERR("Could not dequeue pkt because alloc_skb failed");
293 }
294 }
295
296 /* Now, try to send a reliable pkt. We can only send a
297 * reliable packet if the number of packets sent but not yet ack'ed
298 * is < than the winsize
299 */
300
301 spin_lock_irqsave_nested(&bcsp->unack.lock, flags, SINGLE_DEPTH_NESTING);
302
303 if (bcsp->unack.qlen < BCSP_TXWINSIZE) {
304 skb = skb_dequeue(&bcsp->rel);
305 if (skb != NULL) {
306 struct sk_buff *nskb;
307
308 nskb = bcsp_prepare_pkt(bcsp, skb->data, skb->len,
309 hci_skb_pkt_type(skb));
310 if (nskb) {
311 __skb_queue_tail(&bcsp->unack, skb);
312 mod_timer(&bcsp->tbcsp, jiffies + HZ / 4);
313 spin_unlock_irqrestore(&bcsp->unack.lock, flags);
314 return nskb;
315 } else {
316 skb_queue_head(&bcsp->rel, skb);
317 BT_ERR("Could not dequeue pkt because alloc_skb failed");
318 }
319 }
320 }
321
322 spin_unlock_irqrestore(&bcsp->unack.lock, flags);
323
324 /* We could not send a reliable packet, either because there are
325 * none or because there are too many unack'ed pkts. Did we receive
326 * any packets we have not acknowledged yet ?
327 */
328
329 if (bcsp->txack_req) {
330 /* if so, craft an empty ACK pkt and send it on BCSP unreliable
331 * channel 0
332 */
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)
396 */
397static void bcsp_handle_le_pkt(struct hci_uart *hu)
398{
399 struct bcsp_struct *bcsp = hu->priv;
400 u8 conf_pkt[4] = { 0xad, 0xef, 0xac, 0xed };
401 u8 conf_rsp_pkt[4] = { 0xde, 0xad, 0xd0, 0xd0 };
402 u8 sync_pkt[4] = { 0xda, 0xdc, 0xed, 0xed };
403
404 /* spot "conf" pkts and reply with a "conf rsp" pkt */
405 if (bcsp->rx_skb->data[1] >> 4 == 4 && bcsp->rx_skb->data[2] == 0 &&
406 !memcmp(&bcsp->rx_skb->data[4], conf_pkt, 4)) {
407 struct sk_buff *nskb = alloc_skb(4, GFP_ATOMIC);
408
409 BT_DBG("Found a LE conf pkt");
410 if (!nskb)
411 return;
412 skb_put_data(nskb, conf_rsp_pkt, 4);
413 hci_skb_pkt_type(nskb) = BCSP_LE_PKT;
414
415 skb_queue_head(&bcsp->unrel, nskb);
416 hci_uart_tx_wakeup(hu);
417 }
418 /* Spot "sync" pkts. If we find one...disaster! */
419 else if (bcsp->rx_skb->data[1] >> 4 == 4 && bcsp->rx_skb->data[2] == 0 &&
420 !memcmp(&bcsp->rx_skb->data[4], sync_pkt, 4)) {
421 BT_ERR("Found a LE sync pkt, card has reset");
422 }
423}
424
425static inline void bcsp_unslip_one_byte(struct bcsp_struct *bcsp, unsigned char byte)
426{
427 const u8 c0 = 0xc0, db = 0xdb;
428
429 switch (bcsp->rx_esc_state) {
430 case BCSP_ESCSTATE_NOESC:
431 switch (byte) {
432 case 0xdb:
433 bcsp->rx_esc_state = BCSP_ESCSTATE_ESC;
434 break;
435 default:
436 skb_put_data(bcsp->rx_skb, &byte, 1);
437 if ((bcsp->rx_skb->data[0] & 0x40) != 0 &&
438 bcsp->rx_state != BCSP_W4_CRC)
439 bcsp_crc_update(&bcsp->message_crc, byte);
440 bcsp->rx_count--;
441 }
442 break;
443
444 case BCSP_ESCSTATE_ESC:
445 switch (byte) {
446 case 0xdc:
447 skb_put_data(bcsp->rx_skb, &c0, 1);
448 if ((bcsp->rx_skb->data[0] & 0x40) != 0 &&
449 bcsp->rx_state != BCSP_W4_CRC)
450 bcsp_crc_update(&bcsp->message_crc, 0xc0);
451 bcsp->rx_esc_state = BCSP_ESCSTATE_NOESC;
452 bcsp->rx_count--;
453 break;
454
455 case 0xdd:
456 skb_put_data(bcsp->rx_skb, &db, 1);
457 if ((bcsp->rx_skb->data[0] & 0x40) != 0 &&
458 bcsp->rx_state != BCSP_W4_CRC)
459 bcsp_crc_update(&bcsp->message_crc, 0xdb);
460 bcsp->rx_esc_state = BCSP_ESCSTATE_NOESC;
461 bcsp->rx_count--;
462 break;
463
464 default:
465 BT_ERR("Invalid byte %02x after esc byte", byte);
466 kfree_skb(bcsp->rx_skb);
467 bcsp->rx_skb = NULL;
468 bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
469 bcsp->rx_count = 0;
470 }
471 }
472}
473
474static void bcsp_complete_rx_pkt(struct hci_uart *hu)
475{
476 struct bcsp_struct *bcsp = hu->priv;
477 int pass_up = 0;
478
479 if (bcsp->rx_skb->data[0] & 0x80) { /* reliable pkt */
480 BT_DBG("Received seqno %u from card", bcsp->rxseq_txack);
481
482 /* check the rx sequence number is as expected */
483 if ((bcsp->rx_skb->data[0] & 0x07) == bcsp->rxseq_txack) {
484 bcsp->rxseq_txack++;
485 bcsp->rxseq_txack %= 0x8;
486 } else {
487 /* handle re-transmitted packet or
488 * when packet was missed
489 */
490 BT_ERR("Out-of-order packet arrived, got %u expected %u",
491 bcsp->rx_skb->data[0] & 0x07, bcsp->rxseq_txack);
492
493 /* do not process out-of-order packet payload */
494 pass_up = 2;
495 }
496
497 /* send current txack value to all received reliable packets */
498 bcsp->txack_req = 1;
499
500 /* If needed, transmit an ack pkt */
501 hci_uart_tx_wakeup(hu);
502 }
503
504 bcsp->rxack = (bcsp->rx_skb->data[0] >> 3) & 0x07;
505 BT_DBG("Request for pkt %u from card", bcsp->rxack);
506
507 /* handle received ACK indications,
508 * including those from out-of-order packets
509 */
510 bcsp_pkt_cull(bcsp);
511
512 if (pass_up != 2) {
513 if ((bcsp->rx_skb->data[1] & 0x0f) == 6 &&
514 (bcsp->rx_skb->data[0] & 0x80)) {
515 hci_skb_pkt_type(bcsp->rx_skb) = HCI_ACLDATA_PKT;
516 pass_up = 1;
517 } else if ((bcsp->rx_skb->data[1] & 0x0f) == 5 &&
518 (bcsp->rx_skb->data[0] & 0x80)) {
519 hci_skb_pkt_type(bcsp->rx_skb) = HCI_EVENT_PKT;
520 pass_up = 1;
521 } else if ((bcsp->rx_skb->data[1] & 0x0f) == 7) {
522 hci_skb_pkt_type(bcsp->rx_skb) = HCI_SCODATA_PKT;
523 pass_up = 1;
524 } else if ((bcsp->rx_skb->data[1] & 0x0f) == 1 &&
525 !(bcsp->rx_skb->data[0] & 0x80)) {
526 bcsp_handle_le_pkt(hu);
527 pass_up = 0;
528 } else {
529 pass_up = 0;
530 }
531 }
532
533 if (pass_up == 0) {
534 struct hci_event_hdr hdr;
535 u8 desc = (bcsp->rx_skb->data[1] & 0x0f);
536
537 if (desc != 0 && desc != 1) {
538 if (hciextn) {
539 desc |= 0xc0;
540 skb_pull(bcsp->rx_skb, 4);
541 memcpy(skb_push(bcsp->rx_skb, 1), &desc, 1);
542
543 hdr.evt = 0xff;
544 hdr.plen = bcsp->rx_skb->len;
545 memcpy(skb_push(bcsp->rx_skb, HCI_EVENT_HDR_SIZE), &hdr, HCI_EVENT_HDR_SIZE);
546 hci_skb_pkt_type(bcsp->rx_skb) = HCI_EVENT_PKT;
547
548 hci_recv_frame(hu->hdev, bcsp->rx_skb);
549 } else {
550 BT_ERR("Packet for unknown channel (%u %s)",
551 bcsp->rx_skb->data[1] & 0x0f,
552 bcsp->rx_skb->data[0] & 0x80 ?
553 "reliable" : "unreliable");
554 kfree_skb(bcsp->rx_skb);
555 }
556 } else
557 kfree_skb(bcsp->rx_skb);
558 } else if (pass_up == 1) {
559 /* Pull out BCSP hdr */
560 skb_pull(bcsp->rx_skb, 4);
561
562 hci_recv_frame(hu->hdev, bcsp->rx_skb);
563 } else {
564 /* ignore packet payload of already ACKed re-transmitted
565 * packets or when a packet was missed in the BCSP window
566 */
567 kfree_skb(bcsp->rx_skb);
568 }
569
570 bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
571 bcsp->rx_skb = NULL;
572}
573
574static u16 bscp_get_crc(struct bcsp_struct *bcsp)
575{
576 return get_unaligned_be16(&bcsp->rx_skb->data[bcsp->rx_skb->len - 2]);
577}
578
579/* Recv data */
580static int bcsp_recv(struct hci_uart *hu, const void *data, int count)
581{
582 struct bcsp_struct *bcsp = hu->priv;
583 const unsigned char *ptr;
584
585 BT_DBG("hu %p count %d rx_state %d rx_count %ld",
586 hu, count, bcsp->rx_state, bcsp->rx_count);
587
588 ptr = data;
589 while (count) {
590 if (bcsp->rx_count) {
591 if (*ptr == 0xc0) {
592 BT_ERR("Short BCSP packet");
593 kfree_skb(bcsp->rx_skb);
594 bcsp->rx_state = BCSP_W4_PKT_START;
595 bcsp->rx_count = 0;
596 } else
597 bcsp_unslip_one_byte(bcsp, *ptr);
598
599 ptr++; count--;
600 continue;
601 }
602
603 switch (bcsp->rx_state) {
604 case BCSP_W4_BCSP_HDR:
605 if ((0xff & (u8)~(bcsp->rx_skb->data[0] + bcsp->rx_skb->data[1] +
606 bcsp->rx_skb->data[2])) != bcsp->rx_skb->data[3]) {
607 BT_ERR("Error in BCSP hdr checksum");
608 kfree_skb(bcsp->rx_skb);
609 bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
610 bcsp->rx_count = 0;
611 continue;
612 }
613 bcsp->rx_state = BCSP_W4_DATA;
614 bcsp->rx_count = (bcsp->rx_skb->data[1] >> 4) +
615 (bcsp->rx_skb->data[2] << 4); /* May be 0 */
616 continue;
617
618 case BCSP_W4_DATA:
619 if (bcsp->rx_skb->data[0] & 0x40) { /* pkt with crc */
620 bcsp->rx_state = BCSP_W4_CRC;
621 bcsp->rx_count = 2;
622 } else
623 bcsp_complete_rx_pkt(hu);
624 continue;
625
626 case BCSP_W4_CRC:
627 if (bitrev16(bcsp->message_crc) != bscp_get_crc(bcsp)) {
628 BT_ERR("Checksum failed: computed %04x received %04x",
629 bitrev16(bcsp->message_crc),
630 bscp_get_crc(bcsp));
631
632 kfree_skb(bcsp->rx_skb);
633 bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
634 bcsp->rx_count = 0;
635 continue;
636 }
637 skb_trim(bcsp->rx_skb, bcsp->rx_skb->len - 2);
638 bcsp_complete_rx_pkt(hu);
639 continue;
640
641 case BCSP_W4_PKT_DELIMITER:
642 switch (*ptr) {
643 case 0xc0:
644 bcsp->rx_state = BCSP_W4_PKT_START;
645 break;
646 default:
647 /*BT_ERR("Ignoring byte %02x", *ptr);*/
648 break;
649 }
650 ptr++; count--;
651 break;
652
653 case BCSP_W4_PKT_START:
654 switch (*ptr) {
655 case 0xc0:
656 ptr++; count--;
657 break;
658
659 default:
660 bcsp->rx_state = BCSP_W4_BCSP_HDR;
661 bcsp->rx_count = 4;
662 bcsp->rx_esc_state = BCSP_ESCSTATE_NOESC;
663 BCSP_CRC_INIT(bcsp->message_crc);
664
665 /* Do not increment ptr or decrement count
666 * Allocate packet. Max len of a BCSP pkt=
667 * 0xFFF (payload) +4 (header) +2 (crc)
668 */
669
670 bcsp->rx_skb = bt_skb_alloc(0x1005, GFP_ATOMIC);
671 if (!bcsp->rx_skb) {
672 BT_ERR("Can't allocate mem for new packet");
673 bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
674 bcsp->rx_count = 0;
675 return 0;
676 }
677 break;
678 }
679 break;
680 }
681 }
682 return count;
683}
684
685 /* Arrange to retransmit all messages in the relq. */
686static void bcsp_timed_event(struct timer_list *t)
687{
688 struct bcsp_struct *bcsp = from_timer(bcsp, t, tbcsp);
689 struct hci_uart *hu = bcsp->hu;
690 struct sk_buff *skb;
691 unsigned long flags;
692
693 BT_DBG("hu %p retransmitting %u pkts", hu, bcsp->unack.qlen);
694
695 spin_lock_irqsave_nested(&bcsp->unack.lock, flags, SINGLE_DEPTH_NESTING);
696
697 while ((skb = __skb_dequeue_tail(&bcsp->unack)) != NULL) {
698 bcsp->msgq_txseq = (bcsp->msgq_txseq - 1) & 0x07;
699 skb_queue_head(&bcsp->rel, skb);
700 }
701
702 spin_unlock_irqrestore(&bcsp->unack.lock, flags);
703
704 hci_uart_tx_wakeup(hu);
705}
706
707static int bcsp_open(struct hci_uart *hu)
708{
709 struct bcsp_struct *bcsp;
710
711 BT_DBG("hu %p", hu);
712
713 bcsp = kzalloc(sizeof(*bcsp), GFP_KERNEL);
714 if (!bcsp)
715 return -ENOMEM;
716
717 hu->priv = bcsp;
718 bcsp->hu = hu;
719 skb_queue_head_init(&bcsp->unack);
720 skb_queue_head_init(&bcsp->rel);
721 skb_queue_head_init(&bcsp->unrel);
722
723 timer_setup(&bcsp->tbcsp, bcsp_timed_event, 0);
724
725 bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
726
727 if (txcrc)
728 bcsp->use_crc = 1;
729
730 return 0;
731}
732
733static int bcsp_close(struct hci_uart *hu)
734{
735 struct bcsp_struct *bcsp = hu->priv;
736
737 del_timer_sync(&bcsp->tbcsp);
738
739 hu->priv = NULL;
740
741 BT_DBG("hu %p", hu);
742
743 skb_queue_purge(&bcsp->unack);
744 skb_queue_purge(&bcsp->rel);
745 skb_queue_purge(&bcsp->unrel);
746
747 if (bcsp->rx_skb) {
748 kfree_skb(bcsp->rx_skb);
749 bcsp->rx_skb = NULL;
750 }
751
752 kfree(bcsp);
753 return 0;
754}
755
756static const struct hci_uart_proto bcsp = {
757 .id = HCI_UART_BCSP,
758 .name = "BCSP",
759 .open = bcsp_open,
760 .close = bcsp_close,
761 .enqueue = bcsp_enqueue,
762 .dequeue = bcsp_dequeue,
763 .recv = bcsp_recv,
764 .flush = bcsp_flush
765};
766
767int __init bcsp_init(void)
768{
769 return hci_uart_register_proto(&bcsp);
770}
771
772int __exit bcsp_deinit(void)
773{
774 return hci_uart_unregister_proto(&bcsp);
775}
776
777module_param(txcrc, bool, 0644);
778MODULE_PARM_DESC(txcrc, "Transmit CRC with every BCSP packet");
779
780module_param(hciextn, bool, 0644);
781MODULE_PARM_DESC(hciextn, "Convert HCI Extensions into BCSP packets");