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