text: /*
   *
   *  Bluetooth HCI UART driver
   *
   *  Copyright (C) 2000-2001  Qualcomm Incorporated
   *  Copyright (C) 2002-2003  Maxim Krasnyansky <maxk@qualcomm.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 <net/bluetooth/bluetooth.h>
  #include <net/bluetooth/hci_core.h>
  
  #include "hci_uart.h"
  
  #define VERSION "1.2"
  
  struct h4_struct {
  	unsigned long rx_state;
  	unsigned long rx_count;
  	struct sk_buff *rx_skb;
  	struct sk_buff_head txq;
  };
  
  /* Initialize protocol */
  static int h4_open(struct hci_uart *hu)
  {
  	struct h4_struct *h4;
  
  	BT_DBG("hu %p", hu);
  
  	h4 = kzalloc(sizeof(*h4), GFP_KERNEL);
  	if (!h4)
  		return -ENOMEM;
  
  	skb_queue_head_init(&h4->txq);
  
  	hu->priv = h4;
  	return 0;
  }
  
  /* Flush protocol data */
  static int h4_flush(struct hci_uart *hu)
  {
  	struct h4_struct *h4 = hu->priv;
  
  	BT_DBG("hu %p", hu);
  
  	skb_queue_purge(&h4->txq);
  
  	return 0;
  }
  
  /* Close protocol */
  static int h4_close(struct hci_uart *hu)
  {
  	struct h4_struct *h4 = hu->priv;
  
  	hu->priv = NULL;
  
  	BT_DBG("hu %p", hu);
  
  	skb_queue_purge(&h4->txq);
  
  	kfree_skb(h4->rx_skb);
  
  	hu->priv = NULL;
  	kfree(h4);
  
  	return 0;
  }
  
  /* Enqueue frame for transmittion (padding, crc, etc) */
  static int h4_enqueue(struct hci_uart *hu, struct sk_buff *skb)
  {
  	struct h4_struct *h4 = hu->priv;
  
  	BT_DBG("hu %p skb %p", hu, skb);
  
  	/* Prepend skb with frame type */
  	memcpy(skb_push(skb, 1), &bt_cb(skb)->pkt_type, 1);
  	skb_queue_tail(&h4->txq, skb);
  
  	return 0;
  }
  
  /* Recv data */
  static int h4_recv(struct hci_uart *hu, void *data, int count)
  {
  	int ret;
  
  	if (!test_bit(HCI_UART_REGISTERED, &hu->flags))
  		return -EUNATCH;
  
  	ret = hci_recv_stream_fragment(hu->hdev, data, count);
  	if (ret < 0) {
  		BT_ERR("Frame Reassembly Failed");
  		return ret;
  	}
  
  	return count;
  }
  
  static struct sk_buff *h4_dequeue(struct hci_uart *hu)
  {
  	struct h4_struct *h4 = hu->priv;
  	return skb_dequeue(&h4->txq);
  }
  
  static struct hci_uart_proto h4p = {
  	.id		= HCI_UART_H4,
  	.open		= h4_open,
  	.close		= h4_close,
  	.recv		= h4_recv,
  	.enqueue	= h4_enqueue,
  	.dequeue	= h4_dequeue,
  	.flush		= h4_flush,
  };
  
  int __init h4_init(void)
  {
  	int err = hci_uart_register_proto(&h4p);
  
  	if (!err)
  		BT_INFO("HCI H4 protocol initialized");
  	else
  		BT_ERR("HCI H4 protocol registration failed");
  
  	return err;
  }
  
  int __exit h4_deinit(void)
  {
  	return hci_uart_unregister_proto(&h4p);
  }
  