Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / bluetooth / hci_bcsp.c
diff --git a/kernel/drivers/bluetooth/hci_bcsp.c b/kernel/drivers/bluetooth/hci_bcsp.c
new file mode 100644 (file)
index 0000000..dc8e3d4
--- /dev/null
@@ -0,0 +1,761 @@
+/*
+ *
+ *  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 = 1;
+static bool hciextn = 1;
+
+#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;
+
+       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;
+
+       memcpy(skb_put(skb, 1), &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:
+               memcpy(skb_put(skb, 2), &esc_c0, 2);
+               break;
+       case 0xdb:
+               memcpy(skb_put(skb, 2), &esc_db, 2);
+               break;
+       default:
+               memcpy(skb_put(skb, 1), &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 (bt_cb(skb)->pkt_type) {
+       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;
+
+       bt_cb(nskb)->pkt_type = 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 = bcsp_prepare_pkt(bcsp, skb->data, skb->len, bt_cb(skb)->pkt_type);
+               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 = bcsp_prepare_pkt(bcsp, skb->data, skb->len,
+                                                               bt_cb(skb)->pkt_type);
+                       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;
+               memcpy(skb_put(nskb, 4), conf_rsp_pkt, 4);
+               bt_cb(nskb)->pkt_type = 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:
+                       memcpy(skb_put(bcsp->rx_skb, 1), &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:
+                       memcpy(skb_put(bcsp->rx_skb, 1), &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:
+                       memcpy(skb_put(bcsp->rx_skb, 1), &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;
+
+       if (bcsp->rx_skb->data[0] & 0x80) {     /* reliable pkt */
+               BT_DBG("Received seqno %u from card", bcsp->rxseq_txack);
+               bcsp->rxseq_txack++;
+               bcsp->rxseq_txack %= 0x8;
+               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);
+
+       bcsp_pkt_cull(bcsp);
+       if ((bcsp->rx_skb->data[1] & 0x0f) == 6 &&
+                       bcsp->rx_skb->data[0] & 0x80) {
+               bt_cb(bcsp->rx_skb)->pkt_type = HCI_ACLDATA_PKT;
+               pass_up = 1;
+       } else if ((bcsp->rx_skb->data[1] & 0x0f) == 5 &&
+                       bcsp->rx_skb->data[0] & 0x80) {
+               bt_cb(bcsp->rx_skb)->pkt_type = HCI_EVENT_PKT;
+               pass_up = 1;
+       } else if ((bcsp->rx_skb->data[1] & 0x0f) == 7) {
+               bt_cb(bcsp->rx_skb)->pkt_type = 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) {
+               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);
+                               bt_cb(bcsp->rx_skb)->pkt_type = 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 {
+               /* Pull out BCSP hdr */
+               skb_pull(bcsp->rx_skb, 4);
+
+               hci_recv_frame(hu->hdev, 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_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_state = BCSP_W4_PKT_DELIMITER;
+                               bcsp->rx_count = 0;
+                               continue;
+                       }
+                       if (bcsp->rx_skb->data[0] & 0x80        /* reliable pkt */
+                                       && (bcsp->rx_skb->data[0] & 0x07) != bcsp->rxseq_txack) {
+                               BT_ERR ("Out-of-order packet arrived, got %u expected %u",
+                                       bcsp->rx_skb->data[0] & 0x07, bcsp->rxseq_txack);
+
+                               kfree_skb(bcsp->rx_skb);
+                               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_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(unsigned long arg)
+{
+       struct hci_uart *hu = (struct hci_uart *) arg;
+       struct bcsp_struct *bcsp = hu->priv;
+       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;
+       skb_queue_head_init(&bcsp->unack);
+       skb_queue_head_init(&bcsp->rel);
+       skb_queue_head_init(&bcsp->unrel);
+
+       init_timer(&bcsp->tbcsp);
+       bcsp->tbcsp.function = bcsp_timed_event;
+       bcsp->tbcsp.data     = (u_long) hu;
+
+       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);
+
+       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");