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