Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 799 insertions, 0 deletions

diff --git a/drivers/bluetooth/hci_bcsp.c b/drivers/bluetooth/hci_bcsp.c
new file mode 100644
index 000000000..27829273f
--- /dev/null
+++ b/drivers/bluetooth/hci_bcsp.c
@@ -0,0 +1,799 @@
+/*
+ *
+ *  Bluetooth HCI UART driver
+ *
+ *  Copyright (C) 2002-2003  Fabrizio Gennari <fabrizio.gennari@philips.com>
+ *  Copyright (C) 2004-2005  Marcel Holtmann <marcel@holtmann.org>
+ *
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ */
+
+#include <linux/module.h>
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/fcntl.h>
+#include <linux/interrupt.h>
+#include <linux/ptrace.h>
+#include <linux/poll.h>
+
+#include <linux/slab.h>
+#include <linux/tty.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/signal.h>
+#include <linux/ioctl.h>
+#include <linux/skbuff.h>
+#include <linux/bitrev.h>
+#include <asm/unaligned.h>
+
+#include <net/bluetooth/bluetooth.h>
+#include <net/bluetooth/hci_core.h>
+
+#include "hci_uart.h"
+
+static bool txcrc = true;
+static bool hciextn = true;
+
+#define BCSP_TXWINSIZE	4
+
+#define BCSP_ACK_PKT	0x05
+#define BCSP_LE_PKT	0x06
+
+struct bcsp_struct {
+	struct sk_buff_head unack;	/* Unack'ed packets queue */
+	struct sk_buff_head rel;	/* Reliable packets queue */
+	struct sk_buff_head unrel;	/* Unreliable packets queue */
+
+	unsigned long rx_count;
+	struct	sk_buff *rx_skb;
+	u8	rxseq_txack;		/* rxseq == txack. */
+	u8	rxack;			/* Last packet sent by us that the peer ack'ed */
+	struct	timer_list tbcsp;
+	struct	hci_uart *hu;
+
+	enum {
+		BCSP_W4_PKT_DELIMITER,
+		BCSP_W4_PKT_START,
+		BCSP_W4_BCSP_HDR,
+		BCSP_W4_DATA,
+		BCSP_W4_CRC
+	} rx_state;
+
+	enum {
+		BCSP_ESCSTATE_NOESC,
+		BCSP_ESCSTATE_ESC
+	} rx_esc_state;
+
+	u8	use_crc;
+	u16	message_crc;
+	u8	txack_req;		/* Do we need to send ack's to the peer? */
+
+	/* Reliable packet sequence number - used to assign seq to each rel pkt. */
+	u8	msgq_txseq;
+};
+
+/* ---- BCSP CRC calculation ---- */
+
+/* Table for calculating CRC for polynomial 0x1021, LSB processed first,
+ * initial value 0xffff, bits shifted in reverse order.
+ */
+
+static const u16 crc_table[] = {
+	0x0000, 0x1081, 0x2102, 0x3183,
+	0x4204, 0x5285, 0x6306, 0x7387,
+	0x8408, 0x9489, 0xa50a, 0xb58b,
+	0xc60c, 0xd68d, 0xe70e, 0xf78f
+};
+
+/* Initialise the crc calculator */
+#define BCSP_CRC_INIT(x) x = 0xffff
+
+/* Update crc with next data byte
+ *
+ * Implementation note
+ *     The data byte is treated as two nibbles.  The crc is generated
+ *     in reverse, i.e., bits are fed into the register from the top.
+ */
+static void bcsp_crc_update(u16 *crc, u8 d)
+{
+	u16 reg = *crc;
+
+	reg = (reg >> 4) ^ crc_table[(reg ^ d) & 0x000f];
+	reg = (reg >> 4) ^ crc_table[(reg ^ (d >> 4)) & 0x000f];
+
+	*crc = reg;
+}
+
+/* ---- BCSP core ---- */
+
+static void bcsp_slip_msgdelim(struct sk_buff *skb)
+{
+	const char pkt_delim = 0xc0;
+
+	skb_put_data(skb, &pkt_delim, 1);
+}
+
+static void bcsp_slip_one_byte(struct sk_buff *skb, u8 c)
+{
+	const char esc_c0[2] = { 0xdb, 0xdc };
+	const char esc_db[2] = { 0xdb, 0xdd };
+
+	switch (c) {
+	case 0xc0:
+		skb_put_data(skb, &esc_c0, 2);
+		break;
+	case 0xdb:
+		skb_put_data(skb, &esc_db, 2);
+		break;
+	default:
+		skb_put_data(skb, &c, 1);
+	}
+}
+
+static int bcsp_enqueue(struct hci_uart *hu, struct sk_buff *skb)
+{
+	struct bcsp_struct *bcsp = hu->priv;
+
+	if (skb->len > 0xFFF) {
+		BT_ERR("Packet too long");
+		kfree_skb(skb);
+		return 0;
+	}
+
+	switch (hci_skb_pkt_type(skb)) {
+	case HCI_ACLDATA_PKT:
+	case HCI_COMMAND_PKT:
+		skb_queue_tail(&bcsp->rel, skb);
+		break;
+
+	case HCI_SCODATA_PKT:
+		skb_queue_tail(&bcsp->unrel, skb);
+		break;
+
+	default:
+		BT_ERR("Unknown packet type");
+		kfree_skb(skb);
+		break;
+	}
+
+	return 0;
+}
+
+static struct sk_buff *bcsp_prepare_pkt(struct bcsp_struct *bcsp, u8 *data,
+					int len, int pkt_type)
+{
+	struct sk_buff *nskb;
+	u8 hdr[4], chan;
+	u16 BCSP_CRC_INIT(bcsp_txmsg_crc);
+	int rel, i;
+
+	switch (pkt_type) {
+	case HCI_ACLDATA_PKT:
+		chan = 6;	/* BCSP ACL channel */
+		rel = 1;	/* reliable channel */
+		break;
+	case HCI_COMMAND_PKT:
+		chan = 5;	/* BCSP cmd/evt channel */
+		rel = 1;	/* reliable channel */
+		break;
+	case HCI_SCODATA_PKT:
+		chan = 7;	/* BCSP SCO channel */
+		rel = 0;	/* unreliable channel */
+		break;
+	case BCSP_LE_PKT:
+		chan = 1;	/* BCSP LE channel */
+		rel = 0;	/* unreliable channel */
+		break;
+	case BCSP_ACK_PKT:
+		chan = 0;	/* BCSP internal channel */
+		rel = 0;	/* unreliable channel */
+		break;
+	default:
+		BT_ERR("Unknown packet type");
+		return NULL;
+	}
+
+	if (hciextn && chan == 5) {
+		__le16 opcode = ((struct hci_command_hdr *)data)->opcode;
+
+		/* Vendor specific commands */
+		if (hci_opcode_ogf(__le16_to_cpu(opcode)) == 0x3f) {
+			u8 desc = *(data + HCI_COMMAND_HDR_SIZE);
+
+			if ((desc & 0xf0) == 0xc0) {
+				data += HCI_COMMAND_HDR_SIZE + 1;
+				len  -= HCI_COMMAND_HDR_SIZE + 1;
+				chan = desc & 0x0f;
+			}
+		}
+	}
+
+	/* Max len of packet: (original len +4(bcsp hdr) +2(crc))*2
+	 * (because bytes 0xc0 and 0xdb are escaped, worst case is
+	 * when the packet is all made of 0xc0 and 0xdb :) )
+	 * + 2 (0xc0 delimiters at start and end).
+	 */
+
+	nskb = alloc_skb((len + 6) * 2 + 2, GFP_ATOMIC);
+	if (!nskb)
+		return NULL;
+
+	hci_skb_pkt_type(nskb) = pkt_type;
+
+	bcsp_slip_msgdelim(nskb);
+
+	hdr[0] = bcsp->rxseq_txack << 3;
+	bcsp->txack_req = 0;
+	BT_DBG("We request packet no %u to card", bcsp->rxseq_txack);
+
+	if (rel) {
+		hdr[0] |= 0x80 + bcsp->msgq_txseq;
+		BT_DBG("Sending packet with seqno %u", bcsp->msgq_txseq);
+		bcsp->msgq_txseq = (bcsp->msgq_txseq + 1) & 0x07;
+	}
+
+	if (bcsp->use_crc)
+		hdr[0] |= 0x40;
+
+	hdr[1] = ((len << 4) & 0xff) | chan;
+	hdr[2] = len >> 4;
+	hdr[3] = ~(hdr[0] + hdr[1] + hdr[2]);
+
+	/* Put BCSP header */
+	for (i = 0; i < 4; i++) {
+		bcsp_slip_one_byte(nskb, hdr[i]);
+
+		if (bcsp->use_crc)
+			bcsp_crc_update(&bcsp_txmsg_crc, hdr[i]);
+	}
+
+	/* Put payload */
+	for (i = 0; i < len; i++) {
+		bcsp_slip_one_byte(nskb, data[i]);
+
+		if (bcsp->use_crc)
+			bcsp_crc_update(&bcsp_txmsg_crc, data[i]);
+	}
+
+	/* Put CRC */
+	if (bcsp->use_crc) {
+		bcsp_txmsg_crc = bitrev16(bcsp_txmsg_crc);
+		bcsp_slip_one_byte(nskb, (u8)((bcsp_txmsg_crc >> 8) & 0x00ff));
+		bcsp_slip_one_byte(nskb, (u8)(bcsp_txmsg_crc & 0x00ff));
+	}
+
+	bcsp_slip_msgdelim(nskb);
+	return nskb;
+}
+
+/* This is a rewrite of pkt_avail in ABCSP */
+static struct sk_buff *bcsp_dequeue(struct hci_uart *hu)
+{
+	struct bcsp_struct *bcsp = hu->priv;
+	unsigned long flags;
+	struct sk_buff *skb;
+
+	/* First of all, check for unreliable messages in the queue,
+	 * since they have priority
+	 */
+
+	skb = skb_dequeue(&bcsp->unrel);
+	if (skb != NULL) {
+		struct sk_buff *nskb;
+
+		nskb = bcsp_prepare_pkt(bcsp, skb->data, skb->len,
+					hci_skb_pkt_type(skb));
+		if (nskb) {
+			kfree_skb(skb);
+			return nskb;
+		} else {
+			skb_queue_head(&bcsp->unrel, skb);
+			BT_ERR("Could not dequeue pkt because alloc_skb failed");
+		}
+	}
+
+	/* Now, try to send a reliable pkt. We can only send a
+	 * reliable packet if the number of packets sent but not yet ack'ed
+	 * is < than the winsize
+	 */
+
+	spin_lock_irqsave_nested(&bcsp->unack.lock, flags, SINGLE_DEPTH_NESTING);
+
+	if (bcsp->unack.qlen < BCSP_TXWINSIZE) {
+		skb = skb_dequeue(&bcsp->rel);
+		if (skb != NULL) {
+			struct sk_buff *nskb;
+
+			nskb = bcsp_prepare_pkt(bcsp, skb->data, skb->len,
+						hci_skb_pkt_type(skb));
+			if (nskb) {
+				__skb_queue_tail(&bcsp->unack, skb);
+				mod_timer(&bcsp->tbcsp, jiffies + HZ / 4);
+				spin_unlock_irqrestore(&bcsp->unack.lock, flags);
+				return nskb;
+			} else {
+				skb_queue_head(&bcsp->rel, skb);
+				BT_ERR("Could not dequeue pkt because alloc_skb failed");
+			}
+		}
+	}
+
+	spin_unlock_irqrestore(&bcsp->unack.lock, flags);
+
+	/* We could not send a reliable packet, either because there are
+	 * none or because there are too many unack'ed pkts. Did we receive
+	 * any packets we have not acknowledged yet ?
+	 */
+
+	if (bcsp->txack_req) {
+		/* if so, craft an empty ACK pkt and send it on BCSP unreliable
+		 * channel 0
+		 */
+		struct sk_buff *nskb = bcsp_prepare_pkt(bcsp, NULL, 0, BCSP_ACK_PKT);
+		return nskb;
+	}
+
+	/* We have nothing to send */
+	return NULL;
+}
+
+static int bcsp_flush(struct hci_uart *hu)
+{
+	BT_DBG("hu %p", hu);
+	return 0;
+}
+
+/* Remove ack'ed packets */
+static void bcsp_pkt_cull(struct bcsp_struct *bcsp)
+{
+	struct sk_buff *skb, *tmp;
+	unsigned long flags;
+	int i, pkts_to_be_removed;
+	u8 seqno;
+
+	spin_lock_irqsave(&bcsp->unack.lock, flags);
+
+	pkts_to_be_removed = skb_queue_len(&bcsp->unack);
+	seqno = bcsp->msgq_txseq;
+
+	while (pkts_to_be_removed) {
+		if (bcsp->rxack == seqno)
+			break;
+		pkts_to_be_removed--;
+		seqno = (seqno - 1) & 0x07;
+	}
+
+	if (bcsp->rxack != seqno)
+		BT_ERR("Peer acked invalid packet");
+
+	BT_DBG("Removing %u pkts out of %u, up to seqno %u",
+	       pkts_to_be_removed, skb_queue_len(&bcsp->unack),
+	       (seqno - 1) & 0x07);
+
+	i = 0;
+	skb_queue_walk_safe(&bcsp->unack, skb, tmp) {
+		if (i >= pkts_to_be_removed)
+			break;
+		i++;
+
+		__skb_unlink(skb, &bcsp->unack);
+		kfree_skb(skb);
+	}
+
+	if (skb_queue_empty(&bcsp->unack))
+		del_timer(&bcsp->tbcsp);
+
+	spin_unlock_irqrestore(&bcsp->unack.lock, flags);
+
+	if (i != pkts_to_be_removed)
+		BT_ERR("Removed only %u out of %u pkts", i, pkts_to_be_removed);
+}
+
+/* Handle BCSP link-establishment packets. When we
+ * detect a "sync" packet, symptom that the BT module has reset,
+ * we do nothing :) (yet)
+ */
+static void bcsp_handle_le_pkt(struct hci_uart *hu)
+{
+	struct bcsp_struct *bcsp = hu->priv;
+	u8 conf_pkt[4]     = { 0xad, 0xef, 0xac, 0xed };
+	u8 conf_rsp_pkt[4] = { 0xde, 0xad, 0xd0, 0xd0 };
+	u8 sync_pkt[4]     = { 0xda, 0xdc, 0xed, 0xed };
+
+	/* spot "conf" pkts and reply with a "conf rsp" pkt */
+	if (bcsp->rx_skb->data[1] >> 4 == 4 && bcsp->rx_skb->data[2] == 0 &&
+	    !memcmp(&bcsp->rx_skb->data[4], conf_pkt, 4)) {
+		struct sk_buff *nskb = alloc_skb(4, GFP_ATOMIC);
+
+		BT_DBG("Found a LE conf pkt");
+		if (!nskb)
+			return;
+		skb_put_data(nskb, conf_rsp_pkt, 4);
+		hci_skb_pkt_type(nskb) = BCSP_LE_PKT;
+
+		skb_queue_head(&bcsp->unrel, nskb);
+		hci_uart_tx_wakeup(hu);
+	}
+	/* Spot "sync" pkts. If we find one...disaster! */
+	else if (bcsp->rx_skb->data[1] >> 4 == 4 && bcsp->rx_skb->data[2] == 0 &&
+		 !memcmp(&bcsp->rx_skb->data[4], sync_pkt, 4)) {
+		BT_ERR("Found a LE sync pkt, card has reset");
+	}
+}
+
+static inline void bcsp_unslip_one_byte(struct bcsp_struct *bcsp, unsigned char byte)
+{
+	const u8 c0 = 0xc0, db = 0xdb;
+
+	switch (bcsp->rx_esc_state) {
+	case BCSP_ESCSTATE_NOESC:
+		switch (byte) {
+		case 0xdb:
+			bcsp->rx_esc_state = BCSP_ESCSTATE_ESC;
+			break;
+		default:
+			skb_put_data(bcsp->rx_skb, &byte, 1);
+			if ((bcsp->rx_skb->data[0] & 0x40) != 0 &&
+			    bcsp->rx_state != BCSP_W4_CRC)
+				bcsp_crc_update(&bcsp->message_crc, byte);
+			bcsp->rx_count--;
+		}
+		break;
+
+	case BCSP_ESCSTATE_ESC:
+		switch (byte) {
+		case 0xdc:
+			skb_put_data(bcsp->rx_skb, &c0, 1);
+			if ((bcsp->rx_skb->data[0] & 0x40) != 0 &&
+			    bcsp->rx_state != BCSP_W4_CRC)
+				bcsp_crc_update(&bcsp->message_crc, 0xc0);
+			bcsp->rx_esc_state = BCSP_ESCSTATE_NOESC;
+			bcsp->rx_count--;
+			break;
+
+		case 0xdd:
+			skb_put_data(bcsp->rx_skb, &db, 1);
+			if ((bcsp->rx_skb->data[0] & 0x40) != 0 &&
+			    bcsp->rx_state != BCSP_W4_CRC)
+				bcsp_crc_update(&bcsp->message_crc, 0xdb);
+			bcsp->rx_esc_state = BCSP_ESCSTATE_NOESC;
+			bcsp->rx_count--;
+			break;
+
+		default:
+			BT_ERR("Invalid byte %02x after esc byte", byte);
+			kfree_skb(bcsp->rx_skb);
+			bcsp->rx_skb = NULL;
+			bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
+			bcsp->rx_count = 0;
+		}
+	}
+}
+
+static void bcsp_complete_rx_pkt(struct hci_uart *hu)
+{
+	struct bcsp_struct *bcsp = hu->priv;
+	int pass_up = 0;
+
+	if (bcsp->rx_skb->data[0] & 0x80) {	/* reliable pkt */
+		BT_DBG("Received seqno %u from card", bcsp->rxseq_txack);
+
+		/* check the rx sequence number is as expected */
+		if ((bcsp->rx_skb->data[0] & 0x07) == bcsp->rxseq_txack) {
+			bcsp->rxseq_txack++;
+			bcsp->rxseq_txack %= 0x8;
+		} else {
+			/* handle re-transmitted packet or
+			 * when packet was missed
+			 */
+			BT_ERR("Out-of-order packet arrived, got %u expected %u",
+			       bcsp->rx_skb->data[0] & 0x07, bcsp->rxseq_txack);
+
+			/* do not process out-of-order packet payload */
+			pass_up = 2;
+		}
+
+		/* send current txack value to all received reliable packets */
+		bcsp->txack_req = 1;
+
+		/* If needed, transmit an ack pkt */
+		hci_uart_tx_wakeup(hu);
+	}
+
+	bcsp->rxack = (bcsp->rx_skb->data[0] >> 3) & 0x07;
+	BT_DBG("Request for pkt %u from card", bcsp->rxack);
+
+	/* handle received ACK indications,
+	 * including those from out-of-order packets
+	 */
+	bcsp_pkt_cull(bcsp);
+
+	if (pass_up != 2) {
+		if ((bcsp->rx_skb->data[1] & 0x0f) == 6 &&
+		    (bcsp->rx_skb->data[0] & 0x80)) {
+			hci_skb_pkt_type(bcsp->rx_skb) = HCI_ACLDATA_PKT;
+			pass_up = 1;
+		} else if ((bcsp->rx_skb->data[1] & 0x0f) == 5 &&
+			   (bcsp->rx_skb->data[0] & 0x80)) {
+			hci_skb_pkt_type(bcsp->rx_skb) = HCI_EVENT_PKT;
+			pass_up = 1;
+		} else if ((bcsp->rx_skb->data[1] & 0x0f) == 7) {
+			hci_skb_pkt_type(bcsp->rx_skb) = HCI_SCODATA_PKT;
+			pass_up = 1;
+		} else if ((bcsp->rx_skb->data[1] & 0x0f) == 1 &&
+			   !(bcsp->rx_skb->data[0] & 0x80)) {
+			bcsp_handle_le_pkt(hu);
+			pass_up = 0;
+		} else {
+			pass_up = 0;
+		}
+	}
+
+	if (pass_up == 0) {
+		struct hci_event_hdr hdr;
+		u8 desc = (bcsp->rx_skb->data[1] & 0x0f);
+
+		if (desc != 0 && desc != 1) {
+			if (hciextn) {
+				desc |= 0xc0;
+				skb_pull(bcsp->rx_skb, 4);
+				memcpy(skb_push(bcsp->rx_skb, 1), &desc, 1);
+
+				hdr.evt = 0xff;
+				hdr.plen = bcsp->rx_skb->len;
+				memcpy(skb_push(bcsp->rx_skb, HCI_EVENT_HDR_SIZE), &hdr, HCI_EVENT_HDR_SIZE);
+				hci_skb_pkt_type(bcsp->rx_skb) = HCI_EVENT_PKT;
+
+				hci_recv_frame(hu->hdev, bcsp->rx_skb);
+			} else {
+				BT_ERR("Packet for unknown channel (%u %s)",
+				       bcsp->rx_skb->data[1] & 0x0f,
+				       bcsp->rx_skb->data[0] & 0x80 ?
+				       "reliable" : "unreliable");
+				kfree_skb(bcsp->rx_skb);
+			}
+		} else
+			kfree_skb(bcsp->rx_skb);
+	} else if (pass_up == 1) {
+		/* Pull out BCSP hdr */
+		skb_pull(bcsp->rx_skb, 4);
+
+		hci_recv_frame(hu->hdev, bcsp->rx_skb);
+	} else {
+		/* ignore packet payload of already ACKed re-transmitted
+		 * packets or when a packet was missed in the BCSP window
+		 */
+		kfree_skb(bcsp->rx_skb);
+	}
+
+	bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
+	bcsp->rx_skb = NULL;
+}
+
+static u16 bscp_get_crc(struct bcsp_struct *bcsp)
+{
+	return get_unaligned_be16(&bcsp->rx_skb->data[bcsp->rx_skb->len - 2]);
+}
+
+/* Recv data */
+static int bcsp_recv(struct hci_uart *hu, const void *data, int count)
+{
+	struct bcsp_struct *bcsp = hu->priv;
+	const unsigned char *ptr;
+
+	BT_DBG("hu %p count %d rx_state %d rx_count %ld",
+	       hu, count, bcsp->rx_state, bcsp->rx_count);
+
+	ptr = data;
+	while (count) {
+		if (bcsp->rx_count) {
+			if (*ptr == 0xc0) {
+				BT_ERR("Short BCSP packet");
+				kfree_skb(bcsp->rx_skb);
+				bcsp->rx_skb = NULL;
+				bcsp->rx_state = BCSP_W4_PKT_START;
+				bcsp->rx_count = 0;
+			} else
+				bcsp_unslip_one_byte(bcsp, *ptr);
+
+			ptr++; count--;
+			continue;
+		}
+
+		switch (bcsp->rx_state) {
+		case BCSP_W4_BCSP_HDR:
+			if ((0xff & (u8)~(bcsp->rx_skb->data[0] + bcsp->rx_skb->data[1] +
+			    bcsp->rx_skb->data[2])) != bcsp->rx_skb->data[3]) {
+				BT_ERR("Error in BCSP hdr checksum");
+				kfree_skb(bcsp->rx_skb);
+				bcsp->rx_skb = NULL;
+				bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
+				bcsp->rx_count = 0;
+				continue;
+			}
+			bcsp->rx_state = BCSP_W4_DATA;
+			bcsp->rx_count = (bcsp->rx_skb->data[1] >> 4) +
+					(bcsp->rx_skb->data[2] << 4);	/* May be 0 */
+			continue;
+
+		case BCSP_W4_DATA:
+			if (bcsp->rx_skb->data[0] & 0x40) {	/* pkt with crc */
+				bcsp->rx_state = BCSP_W4_CRC;
+				bcsp->rx_count = 2;
+			} else
+				bcsp_complete_rx_pkt(hu);
+			continue;
+
+		case BCSP_W4_CRC:
+			if (bitrev16(bcsp->message_crc) != bscp_get_crc(bcsp)) {
+				BT_ERR("Checksum failed: computed %04x received %04x",
+				       bitrev16(bcsp->message_crc),
+				       bscp_get_crc(bcsp));
+
+				kfree_skb(bcsp->rx_skb);
+				bcsp->rx_skb = NULL;
+				bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
+				bcsp->rx_count = 0;
+				continue;
+			}
+			skb_trim(bcsp->rx_skb, bcsp->rx_skb->len - 2);
+			bcsp_complete_rx_pkt(hu);
+			continue;
+
+		case BCSP_W4_PKT_DELIMITER:
+			switch (*ptr) {
+			case 0xc0:
+				bcsp->rx_state = BCSP_W4_PKT_START;
+				break;
+			default:
+				/*BT_ERR("Ignoring byte %02x", *ptr);*/
+				break;
+			}
+			ptr++; count--;
+			break;
+
+		case BCSP_W4_PKT_START:
+			switch (*ptr) {
+			case 0xc0:
+				ptr++; count--;
+				break;
+
+			default:
+				bcsp->rx_state = BCSP_W4_BCSP_HDR;
+				bcsp->rx_count = 4;
+				bcsp->rx_esc_state = BCSP_ESCSTATE_NOESC;
+				BCSP_CRC_INIT(bcsp->message_crc);
+
+				/* Do not increment ptr or decrement count
+				 * Allocate packet. Max len of a BCSP pkt=
+				 * 0xFFF (payload) +4 (header) +2 (crc)
+				 */
+
+				bcsp->rx_skb = bt_skb_alloc(0x1005, GFP_ATOMIC);
+				if (!bcsp->rx_skb) {
+					BT_ERR("Can't allocate mem for new packet");
+					bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
+					bcsp->rx_count = 0;
+					return 0;
+				}
+				break;
+			}
+			break;
+		}
+	}
+	return count;
+}
+
+	/* Arrange to retransmit all messages in the relq. */
+static void bcsp_timed_event(struct timer_list *t)
+{
+	struct bcsp_struct *bcsp = from_timer(bcsp, t, tbcsp);
+	struct hci_uart *hu = bcsp->hu;
+	struct sk_buff *skb;
+	unsigned long flags;
+
+	BT_DBG("hu %p retransmitting %u pkts", hu, bcsp->unack.qlen);
+
+	spin_lock_irqsave_nested(&bcsp->unack.lock, flags, SINGLE_DEPTH_NESTING);
+
+	while ((skb = __skb_dequeue_tail(&bcsp->unack)) != NULL) {
+		bcsp->msgq_txseq = (bcsp->msgq_txseq - 1) & 0x07;
+		skb_queue_head(&bcsp->rel, skb);
+	}
+
+	spin_unlock_irqrestore(&bcsp->unack.lock, flags);
+
+	hci_uart_tx_wakeup(hu);
+}
+
+static int bcsp_open(struct hci_uart *hu)
+{
+	struct bcsp_struct *bcsp;
+
+	BT_DBG("hu %p", hu);
+
+	bcsp = kzalloc(sizeof(*bcsp), GFP_KERNEL);
+	if (!bcsp)
+		return -ENOMEM;
+
+	hu->priv = bcsp;
+	bcsp->hu = hu;
+	skb_queue_head_init(&bcsp->unack);
+	skb_queue_head_init(&bcsp->rel);
+	skb_queue_head_init(&bcsp->unrel);
+
+	timer_setup(&bcsp->tbcsp, bcsp_timed_event, 0);
+
+	bcsp->rx_state = BCSP_W4_PKT_DELIMITER;
+
+	if (txcrc)
+		bcsp->use_crc = 1;
+
+	return 0;
+}
+
+static int bcsp_close(struct hci_uart *hu)
+{
+	struct bcsp_struct *bcsp = hu->priv;
+
+	del_timer_sync(&bcsp->tbcsp);
+
+	hu->priv = NULL;
+
+	BT_DBG("hu %p", hu);
+
+	skb_queue_purge(&bcsp->unack);
+	skb_queue_purge(&bcsp->rel);
+	skb_queue_purge(&bcsp->unrel);
+
+	if (bcsp->rx_skb) {
+		kfree_skb(bcsp->rx_skb);
+		bcsp->rx_skb = NULL;
+	}
+
+	kfree(bcsp);
+	return 0;
+}
+
+static const struct hci_uart_proto bcsp = {
+	.id		= HCI_UART_BCSP,
+	.name		= "BCSP",
+	.open		= bcsp_open,
+	.close		= bcsp_close,
+	.enqueue	= bcsp_enqueue,
+	.dequeue	= bcsp_dequeue,
+	.recv		= bcsp_recv,
+	.flush		= bcsp_flush
+};
+
+int __init bcsp_init(void)
+{
+	return hci_uart_register_proto(&bcsp);
+}
+
+int __exit bcsp_deinit(void)
+{
+	return hci_uart_unregister_proto(&bcsp);
+}
+
+module_param(txcrc, bool, 0644);
+MODULE_PARM_DESC(txcrc, "Transmit CRC with every BCSP packet");
+
+module_param(hciextn, bool, 0644);
+MODULE_PARM_DESC(hciextn, "Convert HCI Extensions into BCSP packets");