drivers/bluetooth/hci_h4.c

   1 /*
   2  *
   3  *  Bluetooth HCI UART driver
   4  *
   5  *  Copyright (C) 2000-2001  Qualcomm Incorporated
   6  *  Copyright (C) 2002-2003  Maxim Krasnyansky <maxk@qualcomm.com>
   7  *  Copyright (C) 2004-2005  Marcel Holtmann <marcel@holtmann.org>
   8  *
   9  *
  10  *  This program is free software; you can redistribute it and/or modify
  11  *  it under the terms of the GNU General Public License as published by
  12  *  the Free Software Foundation; either version 2 of the License, or
  13  *  (at your option) any later version.
  14  *
  15  *  This program is distributed in the hope that it will be useful,
  16  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  *  GNU General Public License for more details.
  19  *
  20  *  You should have received a copy of the GNU General Public License
  21  *  along with this program; if not, write to the Free Software
  22  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  23  *
  24  */
  25
  26 #include <linux/module.h>
  27
  28 #include <linux/kernel.h>
  29 #include <linux/init.h>
  30 #include <linux/types.h>
  31 #include <linux/fcntl.h>
  32 #include <linux/interrupt.h>
  33 #include <linux/ptrace.h>
  34 #include <linux/poll.h>
  35
  36 #include <linux/slab.h>
  37 #include <linux/tty.h>
  38 #include <linux/errno.h>
  39 #include <linux/string.h>
  40 #include <linux/signal.h>
  41 #include <linux/ioctl.h>
  42 #include <linux/skbuff.h>
  43
  44 #include <net/bluetooth/bluetooth.h>
  45 #include <net/bluetooth/hci_core.h>
  46
  47 #include "hci_uart.h"
  48
  49 #define VERSION "1.2"
  50
  51 struct h4_struct {
  52         unsigned long rx_state;
  53         unsigned long rx_count;
  54         struct sk_buff *rx_skb;
  55         struct sk_buff_head txq;
  56 };
  57
  58 /* H4 receiver States */
  59 #define H4_W4_PACKET_TYPE       0
  60 #define H4_W4_EVENT_HDR         1
  61 #define H4_W4_ACL_HDR           2
  62 #define H4_W4_SCO_HDR           3
  63 #define H4_W4_DATA              4
  64
  65 /* Initialize protocol */
  66 static int h4_open(struct hci_uart *hu)
  67 {
  68         struct h4_struct *h4;
  69
  70         BT_DBG("hu %p", hu);
  71
  72         h4 = kzalloc(sizeof(*h4), GFP_KERNEL);
  73         if (!h4)
  74                 return -ENOMEM;
  75
  76         skb_queue_head_init(&h4->txq);
  77
  78         hu->priv = h4;
  79         return 0;
  80 }
  81
  82 /* Flush protocol data */
  83 static int h4_flush(struct hci_uart *hu)
  84 {
  85         struct h4_struct *h4 = hu->priv;
  86
  87         BT_DBG("hu %p", hu);
  88
  89         skb_queue_purge(&h4->txq);
  90
  91         return 0;
  92 }
  93
  94 /* Close protocol */
  95 static int h4_close(struct hci_uart *hu)
  96 {
  97         struct h4_struct *h4 = hu->priv;
  98
  99         hu->priv = NULL;
 100
 101         BT_DBG("hu %p", hu);
 102
 103         skb_queue_purge(&h4->txq);
 104
 105         kfree_skb(h4->rx_skb);
 106
 107         hu->priv = NULL;
 108         kfree(h4);
 109
 110         return 0;
 111 }
 112
 113 /* Enqueue frame for transmittion (padding, crc, etc) */
 114 static int h4_enqueue(struct hci_uart *hu, struct sk_buff *skb)
 115 {
 116         struct h4_struct *h4 = hu->priv;
 117
 118         BT_DBG("hu %p skb %p", hu, skb);
 119
 120         /* Prepend skb with frame type */
 121         memcpy(skb_push(skb, 1), &bt_cb(skb)->pkt_type, 1);
 122         skb_queue_tail(&h4->txq, skb);
 123
 124         return 0;
 125 }
 126
 127 static inline int h4_check_data_len(struct h4_struct *h4, int len)
 128 {
 129         int room = skb_tailroom(h4->rx_skb);
 130
 131         BT_DBG("len %d room %d", len, room);
 132
 133         if (!len) {
 134                 hci_recv_frame(h4->rx_skb);
 135         } else if (len > room) {
 136                 BT_ERR("Data length is too large");
 137                 kfree_skb(h4->rx_skb);
 138         } else {
 139                 h4->rx_state = H4_W4_DATA;
 140                 h4->rx_count = len;
 141                 return len;
 142         }
 143
 144         h4->rx_state = H4_W4_PACKET_TYPE;
 145         h4->rx_skb   = NULL;
 146         h4->rx_count = 0;
 147
 148         return 0;
 149 }
 150
 151 /* Recv data */
 152 static int h4_recv(struct hci_uart *hu, void *data, int count)
 153 {
 154         int ret;
 155
 156         if (!test_bit(HCI_UART_REGISTERED, &hu->flags))
 157                 return -EUNATCH;
 158
 159         ret = hci_recv_stream_fragment(hu->hdev, data, count);
 160         if (ret < 0) {
 161                 BT_ERR("Frame Reassembly Failed");
 162                 return ret;
 163         }
 164
 165         return count;
 166 }
 167
 168 static struct sk_buff *h4_dequeue(struct hci_uart *hu)
 169 {
 170         struct h4_struct *h4 = hu->priv;
 171         return skb_dequeue(&h4->txq);
 172 }
 173
 174 static struct hci_uart_proto h4p = {
 175         .id             = HCI_UART_H4,
 176         .open           = h4_open,
 177         .close          = h4_close,
 178         .recv           = h4_recv,
 179         .enqueue        = h4_enqueue,
 180         .dequeue        = h4_dequeue,
 181         .flush          = h4_flush,
 182 };
 183
 184 int __init h4_init(void)
 185 {
 186         int err = hci_uart_register_proto(&h4p);
 187
 188         if (!err)
 189                 BT_INFO("HCI H4 protocol initialized");
 190         else
 191                 BT_ERR("HCI H4 protocol registration failed");
 192
 193         return err;
 194 }
 195
 196 int __exit h4_deinit(void)
 197 {
 198         return hci_uart_unregister_proto(&h4p);
 199 }