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/config.h>
  27 #include <linux/module.h>
  28
  29 #include <linux/kernel.h>
  30 #include <linux/init.h>
  31 #include <linux/sched.h>
  32 #include <linux/types.h>
  33 #include <linux/fcntl.h>
  34 #include <linux/interrupt.h>
  35 #include <linux/ptrace.h>
  36 #include <linux/poll.h>
  37
  38 #include <linux/slab.h>
  39 #include <linux/tty.h>
  40 #include <linux/errno.h>
  41 #include <linux/string.h>
  42 #include <linux/signal.h>
  43 #include <linux/ioctl.h>
  44 #include <linux/skbuff.h>
  45
  46 #include <net/bluetooth/bluetooth.h>
  47 #include <net/bluetooth/hci_core.h>
  48
  49 #include "hci_uart.h"
  50
  51 #ifndef CONFIG_BT_HCIUART_DEBUG
  52 #undef  BT_DBG
  53 #define BT_DBG( A... )
  54 #endif
  55
  56 #define VERSION "1.2"
  57
  58 struct h4_struct {
  59         unsigned long rx_state;
  60         unsigned long rx_count;
  61         struct sk_buff *rx_skb;
  62         struct sk_buff_head txq;
  63 };
  64
  65 /* H4 receiver States */
  66 #define H4_W4_PACKET_TYPE       0
  67 #define H4_W4_EVENT_HDR         1
  68 #define H4_W4_ACL_HDR           2
  69 #define H4_W4_SCO_HDR           3
  70 #define H4_W4_DATA              4
  71
  72 /* Initialize protocol */
  73 static int h4_open(struct hci_uart *hu)
  74 {
  75         struct h4_struct *h4;
  76
  77         BT_DBG("hu %p", hu);
  78
  79         h4 = kmalloc(sizeof(*h4), GFP_ATOMIC);
  80         if (!h4)
  81                 return -ENOMEM;
  82
  83         memset(h4, 0, sizeof(*h4));
  84
  85         skb_queue_head_init(&h4->txq);
  86
  87         hu->priv = h4;
  88         return 0;
  89 }
  90
  91 /* Flush protocol data */
  92 static int h4_flush(struct hci_uart *hu)
  93 {
  94         struct h4_struct *h4 = hu->priv;
  95
  96         BT_DBG("hu %p", hu);
  97
  98         skb_queue_purge(&h4->txq);
  99
 100         return 0;
 101 }
 102
 103 /* Close protocol */
 104 static int h4_close(struct hci_uart *hu)
 105 {
 106         struct h4_struct *h4 = hu->priv;
 107
 108         hu->priv = NULL;
 109
 110         BT_DBG("hu %p", hu);
 111
 112         skb_queue_purge(&h4->txq);
 113
 114         if (h4->rx_skb)
 115                 kfree_skb(h4->rx_skb);
 116
 117         hu->priv = NULL;
 118         kfree(h4);
 119
 120         return 0;
 121 }
 122
 123 /* Enqueue frame for transmittion (padding, crc, etc) */
 124 static int h4_enqueue(struct hci_uart *hu, struct sk_buff *skb)
 125 {
 126         struct h4_struct *h4 = hu->priv;
 127
 128         BT_DBG("hu %p skb %p", hu, skb);
 129
 130         /* Prepend skb with frame type */
 131         memcpy(skb_push(skb, 1), &bt_cb(skb)->pkt_type, 1);
 132         skb_queue_tail(&h4->txq, skb);
 133
 134         return 0;
 135 }
 136
 137 static inline int h4_check_data_len(struct h4_struct *h4, int len)
 138 {
 139         register int room = skb_tailroom(h4->rx_skb);
 140
 141         BT_DBG("len %d room %d", len, room);
 142
 143         if (!len) {
 144                 hci_recv_frame(h4->rx_skb);
 145         } else if (len > room) {
 146                 BT_ERR("Data length is too large");
 147                 kfree_skb(h4->rx_skb);
 148         } else {
 149                 h4->rx_state = H4_W4_DATA;
 150                 h4->rx_count = len;
 151                 return len;
 152         }
 153
 154         h4->rx_state = H4_W4_PACKET_TYPE;
 155         h4->rx_skb   = NULL;
 156         h4->rx_count = 0;
 157
 158         return 0;
 159 }
 160
 161 /* Recv data */
 162 static int h4_recv(struct hci_uart *hu, void *data, int count)
 163 {
 164         struct h4_struct *h4 = hu->priv;
 165         register char *ptr;
 166         struct hci_event_hdr *eh;
 167         struct hci_acl_hdr   *ah;
 168         struct hci_sco_hdr   *sh;
 169         register int len, type, dlen;
 170
 171         BT_DBG("hu %p count %d rx_state %ld rx_count %ld",
 172                         hu, count, h4->rx_state, h4->rx_count);
 173
 174         ptr = data;
 175         while (count) {
 176                 if (h4->rx_count) {
 177                         len = min_t(unsigned int, h4->rx_count, count);
 178                         memcpy(skb_put(h4->rx_skb, len), ptr, len);
 179                         h4->rx_count -= len; count -= len; ptr += len;
 180
 181                         if (h4->rx_count)
 182                                 continue;
 183
 184                         switch (h4->rx_state) {
 185                         case H4_W4_DATA:
 186                                 BT_DBG("Complete data");
 187
 188                                 hci_recv_frame(h4->rx_skb);
 189
 190                                 h4->rx_state = H4_W4_PACKET_TYPE;
 191                                 h4->rx_skb = NULL;
 192                                 continue;
 193
 194                         case H4_W4_EVENT_HDR:
 195                                 eh = (struct hci_event_hdr *) h4->rx_skb->data;
 196
 197                                 BT_DBG("Event header: evt 0x%2.2x plen %d", eh->evt, eh->plen);
 198
 199                                 h4_check_data_len(h4, eh->plen);
 200                                 continue;
 201
 202                         case H4_W4_ACL_HDR:
 203                                 ah = (struct hci_acl_hdr *) h4->rx_skb->data;
 204                                 dlen = __le16_to_cpu(ah->dlen);
 205
 206                                 BT_DBG("ACL header: dlen %d", dlen);
 207
 208                                 h4_check_data_len(h4, dlen);
 209                                 continue;
 210
 211                         case H4_W4_SCO_HDR:
 212                                 sh = (struct hci_sco_hdr *) h4->rx_skb->data;
 213
 214                                 BT_DBG("SCO header: dlen %d", sh->dlen);
 215
 216                                 h4_check_data_len(h4, sh->dlen);
 217                                 continue;
 218                         }
 219                 }
 220
 221                 /* H4_W4_PACKET_TYPE */
 222                 switch (*ptr) {
 223                 case HCI_EVENT_PKT:
 224                         BT_DBG("Event packet");
 225                         h4->rx_state = H4_W4_EVENT_HDR;
 226                         h4->rx_count = HCI_EVENT_HDR_SIZE;
 227                         type = HCI_EVENT_PKT;
 228                         break;
 229
 230                 case HCI_ACLDATA_PKT:
 231                         BT_DBG("ACL packet");
 232                         h4->rx_state = H4_W4_ACL_HDR;
 233                         h4->rx_count = HCI_ACL_HDR_SIZE;
 234                         type = HCI_ACLDATA_PKT;
 235                         break;
 236
 237                 case HCI_SCODATA_PKT:
 238                         BT_DBG("SCO packet");
 239                         h4->rx_state = H4_W4_SCO_HDR;
 240                         h4->rx_count = HCI_SCO_HDR_SIZE;
 241                         type = HCI_SCODATA_PKT;
 242                         break;
 243
 244                 default:
 245                         BT_ERR("Unknown HCI packet type %2.2x", (__u8)*ptr);
 246                         hu->hdev->stat.err_rx++;
 247                         ptr++; count--;
 248                         continue;
 249                 };
 250
 251                 ptr++; count--;
 252
 253                 /* Allocate packet */
 254                 h4->rx_skb = bt_skb_alloc(HCI_MAX_FRAME_SIZE, GFP_ATOMIC);
 255                 if (!h4->rx_skb) {
 256                         BT_ERR("Can't allocate mem for new packet");
 257                         h4->rx_state = H4_W4_PACKET_TYPE;
 258                         h4->rx_count = 0;
 259                         return 0;
 260                 }
 261
 262                 h4->rx_skb->dev = (void *) hu->hdev;
 263                 bt_cb(h4->rx_skb)->pkt_type = type;
 264         }
 265
 266         return count;
 267 }
 268
 269 static struct sk_buff *h4_dequeue(struct hci_uart *hu)
 270 {
 271         struct h4_struct *h4 = hu->priv;
 272         return skb_dequeue(&h4->txq);
 273 }
 274
 275 static struct hci_uart_proto h4p = {
 276         .id             = HCI_UART_H4,
 277         .open           = h4_open,
 278         .close          = h4_close,
 279         .recv           = h4_recv,
 280         .enqueue        = h4_enqueue,
 281         .dequeue        = h4_dequeue,
 282         .flush          = h4_flush,
 283 };
 284
 285 int h4_init(void)
 286 {
 287         int err = hci_uart_register_proto(&h4p);
 288
 289         if (!err)
 290                 BT_INFO("HCI H4 protocol initialized");
 291         else
 292                 BT_ERR("HCI H4 protocol registration failed");
 293
 294         return err;
 295 }
 296
 297 int h4_deinit(void)
 298 {
 299         return hci_uart_unregister_proto(&h4p);
 300 }