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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 dev_kfree_skb_irq(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_skb = NULL;
595 bcsp->rx_state = BCSP_W4_PKT_START;
596 bcsp->rx_count = 0;
597 } else
598 bcsp_unslip_one_byte(bcsp, *ptr);
599
600 ptr++; count--;
601 continue;
602 }
603
604 switch (bcsp->rx_state) {
605 case BCSP_W4_BCSP_HDR:
606 if ((0xff & (u8)~(bcsp->rx_skb->data[0] + bcsp->rx_skb->data[1] +
607 bcsp->rx_skb->data[2])) != bcsp->rx_skb->data[3]) {
608 BT_ERR("Error in BCSP hdr checksum");
609 kfree_skb(bcsp->rx_skb);
610 bcsp->rx_skb = NULL;
611 bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
612 bcsp->rx_count = 0;
613 continue;
614 }
615 bcsp->rx_state = BCSP_W4_DATA;
616 bcsp->rx_count = (bcsp->rx_skb->data[1] >> 4) +
617 (bcsp->rx_skb->data[2] << 4); /* May be 0 */
618 continue;
619
620 case BCSP_W4_DATA:
621 if (bcsp->rx_skb->data[0] & 0x40) { /* pkt with crc */
622 bcsp->rx_state = BCSP_W4_CRC;
623 bcsp->rx_count = 2;
624 } else
625 bcsp_complete_rx_pkt(hu);
626 continue;
627
628 case BCSP_W4_CRC:
629 if (bitrev16(bcsp->message_crc) != bscp_get_crc(bcsp)) {
630 BT_ERR("Checksum failed: computed %04x received %04x",
631 bitrev16(bcsp->message_crc),
632 bscp_get_crc(bcsp));
633
634 kfree_skb(bcsp->rx_skb);
635 bcsp->rx_skb = NULL;
636 bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
637 bcsp->rx_count = 0;
638 continue;
639 }
640 skb_trim(bcsp->rx_skb, bcsp->rx_skb->len - 2);
641 bcsp_complete_rx_pkt(hu);
642 continue;
643
644 case BCSP_W4_PKT_DELIMITER:
645 switch (*ptr) {
646 case 0xc0:
647 bcsp->rx_state = BCSP_W4_PKT_START;
648 break;
649 default:
650 /*BT_ERR("Ignoring byte %02x", *ptr);*/
651 break;
652 }
653 ptr++; count--;
654 break;
655
656 case BCSP_W4_PKT_START:
657 switch (*ptr) {
658 case 0xc0:
659 ptr++; count--;
660 break;
661
662 default:
663 bcsp->rx_state = BCSP_W4_BCSP_HDR;
664 bcsp->rx_count = 4;
665 bcsp->rx_esc_state = BCSP_ESCSTATE_NOESC;
666 BCSP_CRC_INIT(bcsp->message_crc);
667
668 /* Do not increment ptr or decrement count
669 * Allocate packet. Max len of a BCSP pkt=
670 * 0xFFF (payload) +4 (header) +2 (crc)
671 */
672
673 bcsp->rx_skb = bt_skb_alloc(0x1005, GFP_ATOMIC);
674 if (!bcsp->rx_skb) {
675 BT_ERR("Can't allocate mem for new packet");
676 bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
677 bcsp->rx_count = 0;
678 return 0;
679 }
680 break;
681 }
682 break;
683 }
684 }
685 return count;
686}
687
688 /* Arrange to retransmit all messages in the relq. */
689static void bcsp_timed_event(struct timer_list *t)
690{
691 struct bcsp_struct *bcsp = from_timer(bcsp, t, tbcsp);
692 struct hci_uart *hu = bcsp->hu;
693 struct sk_buff *skb;
694 unsigned long flags;
695
696 BT_DBG("hu %p retransmitting %u pkts", hu, bcsp->unack.qlen);
697
698 spin_lock_irqsave_nested(&bcsp->unack.lock, flags, SINGLE_DEPTH_NESTING);
699
700 while ((skb = __skb_dequeue_tail(&bcsp->unack)) != NULL) {
701 bcsp->msgq_txseq = (bcsp->msgq_txseq - 1) & 0x07;
702 skb_queue_head(&bcsp->rel, skb);
703 }
704
705 spin_unlock_irqrestore(&bcsp->unack.lock, flags);
706
707 hci_uart_tx_wakeup(hu);
708}
709
710static int bcsp_open(struct hci_uart *hu)
711{
712 struct bcsp_struct *bcsp;
713
714 BT_DBG("hu %p", hu);
715
716 bcsp = kzalloc(sizeof(*bcsp), GFP_KERNEL);
717 if (!bcsp)
718 return -ENOMEM;
719
720 hu->priv = bcsp;
721 bcsp->hu = hu;
722 skb_queue_head_init(&bcsp->unack);
723 skb_queue_head_init(&bcsp->rel);
724 skb_queue_head_init(&bcsp->unrel);
725
726 timer_setup(&bcsp->tbcsp, bcsp_timed_event, 0);
727
728 bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
729
730 if (txcrc)
731 bcsp->use_crc = 1;
732
733 return 0;
734}
735
736static int bcsp_close(struct hci_uart *hu)
737{
738 struct bcsp_struct *bcsp = hu->priv;
739
740 timer_shutdown_sync(&bcsp->tbcsp);
741
742 hu->priv = NULL;
743
744 BT_DBG("hu %p", hu);
745
746 skb_queue_purge(&bcsp->unack);
747 skb_queue_purge(&bcsp->rel);
748 skb_queue_purge(&bcsp->unrel);
749
750 if (bcsp->rx_skb) {
751 kfree_skb(bcsp->rx_skb);
752 bcsp->rx_skb = NULL;
753 }
754
755 kfree(bcsp);
756 return 0;
757}
758
759static const struct hci_uart_proto bcsp = {
760 .id = HCI_UART_BCSP,
761 .name = "BCSP",
762 .open = bcsp_open,
763 .close = bcsp_close,
764 .enqueue = bcsp_enqueue,
765 .dequeue = bcsp_dequeue,
766 .recv = bcsp_recv,
767 .flush = bcsp_flush
768};
769
770int __init bcsp_init(void)
771{
772 return hci_uart_register_proto(&bcsp);
773}
774
775int __exit bcsp_deinit(void)
776{
777 return hci_uart_unregister_proto(&bcsp);
778}
779
780module_param(txcrc, bool, 0644);
781MODULE_PARM_DESC(txcrc, "Transmit CRC with every BCSP packet");
782
783module_param(hciextn, bool, 0644);
784MODULE_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");