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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");
764