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 = kzalloc(sizeof(*h4), GFP_ATOMIC);
  80         if (!h4)
  81                 return -ENOMEM;
  82
  83         skb_queue_head_init(&h4->txq);
  84
  85         hu->priv = h4;
  86         return 0;
  87 }
  88
  89 /* Flush protocol data */
  90 static int h4_flush(struct hci_uart *hu)
  91 {
  92         struct h4_struct *h4 = hu->priv;
  93
  94         BT_DBG("hu %p", hu);
  95
  96         skb_queue_purge(&h4->txq);
  97
  98         return 0;
  99 }
 100
 101 /* Close protocol */
 102 static int h4_close(struct hci_uart *hu)
 103 {
 104         struct h4_struct *h4 = hu->priv;
 105
 106         hu->priv = NULL;
 107
 108         BT_DBG("hu %p", hu);
 109
 110         skb_queue_purge(&h4->txq);
 111
 112         if (h4->rx_skb)
 113                 kfree_skb(h4->rx_skb);
 114
 115         hu->priv = NULL;
 116         kfree(h4);
 117
 118         return 0;
 119 }
 120
 121 /* Enqueue frame for transmittion (padding, crc, etc) */
 122 static int h4_enqueue(struct hci_uart *hu, struct sk_buff *skb)
 123 {
 124         struct h4_struct *h4 = hu->priv;
 125
 126         BT_DBG("hu %p skb %p", hu, skb);
 127
 128         /* Prepend skb with frame type */
 129         memcpy(skb_push(skb, 1), &bt_cb(skb)->pkt_type, 1);
 130         skb_queue_tail(&h4->txq, skb);
 131
 132         return 0;
 133 }
 134
 135 static inline int h4_check_data_len(struct h4_struct *h4, int len)
 136 {
 137         register int room = skb_tailroom(h4->rx_skb);
 138
 139         BT_DBG("len %d room %d", len, room);
 140
 141         if (!len) {
 142                 hci_recv_frame(h4->rx_skb);
 143         } else if (len > room) {
 144                 BT_ERR("Data length is too large");
 145                 kfree_skb(h4->rx_skb);
 146         } else {
 147                 h4->rx_state = H4_W4_DATA;
 148                 h4->rx_count = len;
 149                 return len;
 150         }
 151
 152         h4->rx_state = H4_W4_PACKET_TYPE;
 153         h4->rx_skb   = NULL;
 154         h4->rx_count = 0;
 155
 156         return 0;
 157 }
 158
 159 /* Recv data */
 160 static int h4_recv(struct hci_uart *hu, void *data, int count)
 161 {
 162         struct h4_struct *h4 = hu->priv;
 163         register char *ptr;
 164         struct hci_event_hdr *eh;
 165         struct hci_acl_hdr   *ah;
 166         struct hci_sco_hdr   *sh;
 167         register int len, type, dlen;
 168
 169         BT_DBG("hu %p count %d rx_state %ld rx_count %ld",
 170                         hu, count, h4->rx_state, h4->rx_count);
 171
 172         ptr = data;
 173         while (count) {
 174                 if (h4->rx_count) {
 175                         len = min_t(unsigned int, h4->rx_count, count);
 176                         memcpy(skb_put(h4->rx_skb, len), ptr, len);
 177                         h4->rx_count -= len; count -= len; ptr += len;
 178
 179                         if (h4->rx_count)
 180                                 continue;
 181
 182                         switch (h4->rx_state) {
 183                         case H4_W4_DATA:
 184                                 BT_DBG("Complete data");
 185
 186                                 hci_recv_frame(h4->rx_skb);
 187
 188                                 h4->rx_state = H4_W4_PACKET_TYPE;
 189                                 h4->rx_skb = NULL;
 190                                 continue;
 191
 192                         case H4_W4_EVENT_HDR:
 193                                 eh = (struct hci_event_hdr *) h4->rx_skb->data;
 194
 195                                 BT_DBG("Event header: evt 0x%2.2x plen %d", eh->evt, eh->plen);
 196
 197                                 h4_check_data_len(h4, eh->plen);
 198                                 continue;
 199
 200                         case H4_W4_ACL_HDR:
 201                                 ah = (struct hci_acl_hdr *) h4->rx_skb->data;
 202                                 dlen = __le16_to_cpu(ah->dlen);
 203
 204                                 BT_DBG("ACL header: dlen %d", dlen);
 205
 206                                 h4_check_data_len(h4, dlen);
 207                                 continue;
 208
 209                         case H4_W4_SCO_HDR:
 210                                 sh = (struct hci_sco_hdr *) h4->rx_skb->data;
 211
 212                                 BT_DBG("SCO header: dlen %d", sh->dlen);
 213
 214                                 h4_check_data_len(h4, sh->dlen);
 215                                 continue;
 216                         }
 217                 }
 218
 219                 /* H4_W4_PACKET_TYPE */
 220                 switch (*ptr) {
 221                 case HCI_EVENT_PKT:
 222                         BT_DBG("Event packet");
 223                         h4->rx_state = H4_W4_EVENT_HDR;
 224                         h4->rx_count = HCI_EVENT_HDR_SIZE;
 225                         type = HCI_EVENT_PKT;
 226                         break;
 227
 228                 case HCI_ACLDATA_PKT:
 229                         BT_DBG("ACL packet");
 230                         h4->rx_state = H4_W4_ACL_HDR;
 231                         h4->rx_count = HCI_ACL_HDR_SIZE;
 232                         type = HCI_ACLDATA_PKT;
 233                         break;
 234
 235                 case HCI_SCODATA_PKT:
 236                         BT_DBG("SCO packet");
 237                         h4->rx_state = H4_W4_SCO_HDR;
 238                         h4->rx_count = HCI_SCO_HDR_SIZE;
 239                         type = HCI_SCODATA_PKT;
 240                         break;
 241
 242                 default:
 243                         BT_ERR("Unknown HCI packet type %2.2x", (__u8)*ptr);
 244                         hu->hdev->stat.err_rx++;
 245                         ptr++; count--;
 246                         continue;
 247                 };
 248
 249                 ptr++; count--;
 250
 251                 /* Allocate packet */
 252                 h4->rx_skb = bt_skb_alloc(HCI_MAX_FRAME_SIZE, GFP_ATOMIC);
 253                 if (!h4->rx_skb) {
 254                         BT_ERR("Can't allocate mem for new packet");
 255                         h4->rx_state = H4_W4_PACKET_TYPE;
 256                         h4->rx_count = 0;
 257                         return 0;
 258                 }
 259
 260                 h4->rx_skb->dev = (void *) hu->hdev;
 261                 bt_cb(h4->rx_skb)->pkt_type = type;
 262         }
 263
 264         return count;
 265 }
 266
 267 static struct sk_buff *h4_dequeue(struct hci_uart *hu)
 268 {
 269         struct h4_struct *h4 = hu->priv;
 270         return skb_dequeue(&h4->txq);
 271 }
 272
 273 static struct hci_uart_proto h4p = {
 274         .id             = HCI_UART_H4,
 275         .open           = h4_open,
 276         .close          = h4_close,
 277         .recv           = h4_recv,
 278         .enqueue        = h4_enqueue,
 279         .dequeue        = h4_dequeue,
 280         .flush          = h4_flush,
 281 };
 282
 283 int h4_init(void)
 284 {
 285         int err = hci_uart_register_proto(&h4p);
 286
 287         if (!err)
 288                 BT_INFO("HCI H4 protocol initialized");
 289         else
 290                 BT_ERR("HCI H4 protocol registration failed");
 291
 292         return err;
 293 }
 294
 295 int h4_deinit(void)
 296 {
 297         return hci_uart_unregister_proto(&h4p);
 298 }