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Merge tag 'mtd/for-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux
[linux-2.6-block.git] / drivers / bluetooth / hci_bcsp.c
CommitLineData
1a59d1b8 1// SPDX-License-Identifier: GPL-2.0-or-later
1da177e4 2/*
0372a662
MH		 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>
1da177e4
LT		 8 */
9
1da177e4
LT		 10#include <linux/module.h>
11
12#include <linux/kernel.h>
13#include <linux/init.h>
1da177e4
LT		 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>
c5ec5140
HH		 27#include <linux/bitrev.h>
28#include <asm/unaligned.h>
1da177e4
LT		 29
30#include <net/bluetooth/bluetooth.h>
31#include <net/bluetooth/hci_core.h>
0372a662 32
1da177e4 33#include "hci_uart.h"
1da177e4 34
bff6b89f
SV		 35static bool txcrc = true;
36static bool hciextn = true;
1da177e4 37
0372a662
MH		 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;
04356052 53 struct hci_uart *hu;
0372a662
MH		 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
1da177e4
LT		 76/* ---- BCSP CRC calculation ---- */
77
78/* Table for calculating CRC for polynomial 0x1021, LSB processed first,
8083ad1c
DJ		 79 * initial value 0xffff, bits shifted in reverse order.
80 */
1da177e4
LT		 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
8805eea2
MZ		 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 */
1da177e4
LT		 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
1da177e4
LT		 108/* ---- BCSP core ---- */
109
110static void bcsp_slip_msgdelim(struct sk_buff *skb)
111{
112 const char pkt_delim = 0xc0;
0372a662 113
59ae1d12 114 skb_put_data(skb, &pkt_delim, 1);
1da177e4
LT		 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:
59ae1d12 124 skb_put_data(skb, &esc_c0, 2);
1da177e4
LT		 125 break;
126 case 0xdb:
59ae1d12 127 skb_put_data(skb, &esc_db, 2);
1da177e4
LT		 128 break;
129 default:
59ae1d12 130 skb_put_data(skb, &c, 1);
1da177e4
LT		 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
618e8bc2 144 switch (hci_skb_pkt_type(skb)) {
1da177e4
LT		 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,
8083ad1c 164 int len, int pkt_type)
1da177e4
LT		 165{
166 struct sk_buff *nskb;
167 u8 hdr[4], chan;
1da177e4 168 u16 BCSP_CRC_INIT(bcsp_txmsg_crc);
20dd6f59 169 int rel, i;
1da177e4
LT		 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) {
c5ec5140 198 __le16 opcode = ((struct hci_command_hdr *)data)->opcode;
1da177e4 199
a9de9248 200 /* Vendor specific commands */
c5ec5140 201 if (hci_opcode_ogf(__le16_to_cpu(opcode)) == 0x3f) {
1da177e4 202 u8 desc = *(data + HCI_COMMAND_HDR_SIZE);
8083ad1c 203
1da177e4
LT		 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
8805eea2
MZ		 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 */
1da177e4
LT		 217
218 nskb = alloc_skb((len + 6) * 2 + 2, GFP_ATOMIC);
219 if (!nskb)
220 return NULL;
221
618e8bc2 222 hci_skb_pkt_type(nskb) = pkt_type;
1da177e4
LT		 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);
dd1589a4 233 bcsp->msgq_txseq = (bcsp->msgq_txseq + 1) & 0x07;
1da177e4 234 }
20dd6f59
MH		 235
236 if (bcsp->use_crc)
237 hdr[0] |= 0x40;
1da177e4
LT		 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]);
20dd6f59
MH		 246
247 if (bcsp->use_crc)
248 bcsp_crc_update(&bcsp_txmsg_crc, hdr[i]);
1da177e4
LT		 249 }
250
251 /* Put payload */
252 for (i = 0; i < len; i++) {
253 bcsp_slip_one_byte(nskb, data[i]);
20dd6f59
MH		 254
255 if (bcsp->use_crc)
256 bcsp_crc_update(&bcsp_txmsg_crc, data[i]);
1da177e4
LT		 257 }
258
1da177e4 259 /* Put CRC */
20dd6f59 260 if (bcsp->use_crc) {
c5ec5140 261 bcsp_txmsg_crc = bitrev16(bcsp_txmsg_crc);
8083ad1c
DJ		 262 bcsp_slip_one_byte(nskb, (u8)((bcsp_txmsg_crc >> 8) & 0x00ff));
263 bcsp_slip_one_byte(nskb, (u8)(bcsp_txmsg_crc & 0x00ff));
20dd6f59 264 }
1da177e4
LT		 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;
8805eea2 276
1da177e4 277 /* First of all, check for unreliable messages in the queue,
8083ad1c
DJ		 278 * since they have priority
279 */
1da177e4 280
a08b15e6
VI		 281 skb = skb_dequeue(&bcsp->unrel);
282 if (skb != NULL) {
618e8bc2
MH		 283 struct sk_buff *nskb;
284
285 nskb = bcsp_prepare_pkt(bcsp, skb->data, skb->len,
286 hci_skb_pkt_type(skb));
1da177e4
LT		 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
8805eea2
MZ		 297 * reliable packet if the number of packets sent but not yet ack'ed
298 * is < than the winsize
299 */
1da177e4 300
f89d75f2 301 spin_lock_irqsave_nested(&bcsp->unack.lock, flags, SINGLE_DEPTH_NESTING);
1da177e4 302
a08b15e6
VI		 303 if (bcsp->unack.qlen < BCSP_TXWINSIZE) {
304 skb = skb_dequeue(&bcsp->rel);
305 if (skb != NULL) {
618e8bc2
MH		 306 struct sk_buff *nskb;
307
308 nskb = bcsp_prepare_pkt(bcsp, skb->data, skb->len,
309 hci_skb_pkt_type(skb));
a08b15e6
VI		 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 }
1da177e4
LT		 319 }
320 }
321
322 spin_unlock_irqrestore(&bcsp->unack.lock, flags);
323
1da177e4 324 /* We could not send a reliable packet, either because there are
8805eea2
MZ		 325 * none or because there are too many unack'ed pkts. Did we receive
326 * any packets we have not acknowledged yet ?
327 */
1da177e4
LT		 328
329 if (bcsp->txack_req) {
330 /* if so, craft an empty ACK pkt and send it on BCSP unreliable
8805eea2
MZ		 331 * channel 0
332 */
1da177e4
LT		 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{
8fc5387c 350 struct sk_buff *skb, *tmp;
1da177e4 351 unsigned long flags;
1da177e4
LT		 352 int i, pkts_to_be_removed;
353 u8 seqno;
354
355 spin_lock_irqsave(&bcsp->unack.lock, flags);
356
8fc5387c 357 pkts_to_be_removed = skb_queue_len(&bcsp->unack);
1da177e4
LT		 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",
8fc5387c
DM		 371 pkts_to_be_removed, skb_queue_len(&bcsp->unack),
372 (seqno - 1) & 0x07);
1da177e4 373
8fc5387c
DM		 374 i = 0;
375 skb_queue_walk_safe(&bcsp->unack, skb, tmp) {
d2e353f7 376 if (i >= pkts_to_be_removed)
8fc5387c 377 break;
d2e353f7 378 i++;
1da177e4 379
1da177e4
LT		 380 __skb_unlink(skb, &bcsp->unack);
381 kfree_skb(skb);
1da177e4 382 }
0372a662 383
8fc5387c 384 if (skb_queue_empty(&bcsp->unack))
1da177e4 385 del_timer(&bcsp->tbcsp);
0372a662 386
1da177e4
LT		 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
8805eea2
MZ		 394 * detect a "sync" packet, symptom that the BT module has reset,
395 * we do nothing :) (yet)
396 */
1da177e4
LT		 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 &&
8083ad1c 406 !memcmp(&bcsp->rx_skb->data[4], conf_pkt, 4)) {
1da177e4
LT		 407 struct sk_buff *nskb = alloc_skb(4, GFP_ATOMIC);
408
409 BT_DBG("Found a LE conf pkt");
410 if (!nskb)
411 return;
59ae1d12 412 skb_put_data(nskb, conf_rsp_pkt, 4);
618e8bc2 413 hci_skb_pkt_type(nskb) = BCSP_LE_PKT;
1da177e4
LT		 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 &&
8083ad1c 420 !memcmp(&bcsp->rx_skb->data[4], sync_pkt, 4)) {
1da177e4
LT		 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:
59ae1d12 436 skb_put_data(bcsp->rx_skb, &byte, 1);
fe8de008 437 if ((bcsp->rx_skb->data[0] & 0x40) != 0 &&
8083ad1c 438 bcsp->rx_state != BCSP_W4_CRC)
1da177e4
LT		 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:
59ae1d12 447 skb_put_data(bcsp->rx_skb, &c0, 1);
fe8de008 448 if ((bcsp->rx_skb->data[0] & 0x40) != 0 &&
8083ad1c 449 bcsp->rx_state != BCSP_W4_CRC)
fe8de008 450 bcsp_crc_update(&bcsp->message_crc, 0xc0);
1da177e4
LT		 451 bcsp->rx_esc_state = BCSP_ESCSTATE_NOESC;
452 bcsp->rx_count--;
453 break;
454
455 case 0xdd:
59ae1d12 456 skb_put_data(bcsp->rx_skb, &db, 1);
fe8de008 457 if ((bcsp->rx_skb->data[0] & 0x40) != 0 &&
8083ad1c 458 bcsp->rx_state != BCSP_W4_CRC)
fe8de008 459 bcsp_crc_update(&bcsp->message_crc, 0xdb);
1da177e4
LT		 460 bcsp->rx_esc_state = BCSP_ESCSTATE_NOESC;
461 bcsp->rx_count--;
462 break;
463
464 default:
fe8de008 465 BT_ERR("Invalid byte %02x after esc byte", byte);
1da177e4
LT		 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
858119e1 474static void bcsp_complete_rx_pkt(struct hci_uart *hu)
1da177e4
LT		 475{
476 struct bcsp_struct *bcsp = hu->priv;
37332ddc 477 int pass_up = 0;
1da177e4
LT		 478
479 if (bcsp->rx_skb->data[0] & 0x80) { /* reliable pkt */
480 BT_DBG("Received seqno %u from card", bcsp->rxseq_txack);
37332ddc
DJ		 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;
1da177e4
LT		 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
37332ddc
DJ		 507 /* handle received ACK indications,
508 * including those from out-of-order packets
509 */
1da177e4 510 bcsp_pkt_cull(bcsp);
37332ddc
DJ		 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) {
1da177e4
LT		 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);
618e8bc2 546 hci_skb_pkt_type(bcsp->rx_skb) = HCI_EVENT_PKT;
1da177e4 547
e1a26170 548 hci_recv_frame(hu->hdev, bcsp->rx_skb);
1da177e4 549 } else {
fe8de008 550 BT_ERR("Packet for unknown channel (%u %s)",
8083ad1c
DJ		 551 bcsp->rx_skb->data[1] & 0x0f,
552 bcsp->rx_skb->data[0] & 0x80 ?
553 "reliable" : "unreliable");
1da177e4
LT		 554 kfree_skb(bcsp->rx_skb);
555 }
556 } else
557 kfree_skb(bcsp->rx_skb);
37332ddc 558 } else if (pass_up == 1) {
1da177e4
LT		 559 /* Pull out BCSP hdr */
560 skb_pull(bcsp->rx_skb, 4);
561
e1a26170 562 hci_recv_frame(hu->hdev, bcsp->rx_skb);
37332ddc
DJ		 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);
1da177e4 568 }
0372a662 569
1da177e4
LT		 570 bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
571 bcsp->rx_skb = NULL;
572}
573
c5ec5140
HH		 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
1da177e4 579/* Recv data */
9d1c40eb 580static int bcsp_recv(struct hci_uart *hu, const void *data, int count)
1da177e4
LT		 581{
582 struct bcsp_struct *bcsp = hu->priv;
9d1c40eb 583 const unsigned char *ptr;
1da177e4 584
8805eea2 585 BT_DBG("hu %p count %d rx_state %d rx_count %ld",
8083ad1c 586 hu, count, bcsp->rx_state, bcsp->rx_count);
1da177e4
LT		 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:
8083ad1c
DJ		 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]) {
1da177e4
LT		 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 }
1da177e4 613 bcsp->rx_state = BCSP_W4_DATA;
8805eea2 614 bcsp->rx_count = (bcsp->rx_skb->data[1] >> 4) +
1da177e4
LT		 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:
c5ec5140 627 if (bitrev16(bcsp->message_crc) != bscp_get_crc(bcsp)) {
8805eea2 628 BT_ERR("Checksum failed: computed %04x received %04x",
8083ad1c
DJ		 629 bitrev16(bcsp->message_crc),
630 bscp_get_crc(bcsp));
1da177e4
LT		 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);
0372a662 664
1da177e4 665 /* Do not increment ptr or decrement count
8805eea2
MZ		 666 * Allocate packet. Max len of a BCSP pkt=
667 * 0xFFF (payload) +4 (header) +2 (crc)
668 */
1da177e4
LT		 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 }
1da177e4
LT		 677 break;
678 }
679 break;
680 }
681 }
682 return count;
683}
684
685 /* Arrange to retransmit all messages in the relq. */
04356052 686static void bcsp_timed_event(struct timer_list *t)
1da177e4 687{
04356052
KC		 688 struct bcsp_struct *bcsp = from_timer(bcsp, t, tbcsp);
689 struct hci_uart *hu = bcsp->hu;
1da177e4
LT		 690 struct sk_buff *skb;
691 unsigned long flags;
692
693 BT_DBG("hu %p retransmitting %u pkts", hu, bcsp->unack.qlen);
694
f89d75f2 695 spin_lock_irqsave_nested(&bcsp->unack.lock, flags, SINGLE_DEPTH_NESTING);
1da177e4
LT		 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
c063af34 713 bcsp = kzalloc(sizeof(*bcsp), GFP_KERNEL);
1da177e4
LT		 714 if (!bcsp)
715 return -ENOMEM;
1da177e4
LT		 716
717 hu->priv = bcsp;
04356052 718 bcsp->hu = hu;
1da177e4
LT		 719 skb_queue_head_init(&bcsp->unack);
720 skb_queue_head_init(&bcsp->rel);
721 skb_queue_head_init(&bcsp->unrel);
722
04356052 723 timer_setup(&bcsp->tbcsp, bcsp_timed_event, 0);
1da177e4
LT		 724
725 bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
726
20dd6f59
MH		 727 if (txcrc)
728 bcsp->use_crc = 1;
729
1da177e4
LT		 730 return 0;
731}
732
733static int bcsp_close(struct hci_uart *hu)
734{
735 struct bcsp_struct *bcsp = hu->priv;
c327cddd
MK		 736
737 del_timer_sync(&bcsp->tbcsp);
738
1da177e4
LT		 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);
1da177e4 746
4ce9146e
TB		 747 if (bcsp->rx_skb) {
748 kfree_skb(bcsp->rx_skb);
749 bcsp->rx_skb = NULL;
750 }
751
1da177e4
LT		 752 kfree(bcsp);
753 return 0;
754}
755
4ee7ef19 756static const struct hci_uart_proto bcsp = {
0372a662 757 .id = HCI_UART_BCSP,
7c40fb8d 758 .name = "BCSP",
0372a662
MH		 759 .open = bcsp_open,
760 .close = bcsp_close,
761 .enqueue = bcsp_enqueue,
762 .dequeue = bcsp_dequeue,
763 .recv = bcsp_recv,
764 .flush = bcsp_flush
1da177e4
LT		 765};
766
f2b94bb9 767int __init bcsp_init(void)
1da177e4 768{
01009eec 769 return hci_uart_register_proto(&bcsp);
1da177e4
LT		 770}
771
f2b94bb9 772int __exit bcsp_deinit(void)
1da177e4
LT		 773{
774 return hci_uart_unregister_proto(&bcsp);
775}
776
20dd6f59
MH		 777module_param(txcrc, bool, 0644);
778MODULE_PARM_DESC(txcrc, "Transmit CRC with every BCSP packet");
779
1da177e4
LT		 780module_param(hciextn, bool, 0644);
781MODULE_PARM_DESC(hciextn, "Convert HCI Extensions into BCSP packets");
Linux 6.x block layer and io_uring tree(s)