drivers/bluetooth/hci_ldisc.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 "2.2"
  50
  51 static struct hci_uart_proto *hup[HCI_UART_MAX_PROTO];
  52
  53 int hci_uart_register_proto(struct hci_uart_proto *p)
  54 {
  55         if (p->id >= HCI_UART_MAX_PROTO)
  56                 return -EINVAL;
  57
  58         if (hup[p->id])
  59                 return -EEXIST;
  60
  61         hup[p->id] = p;
  62
  63         return 0;
  64 }
  65
  66 int hci_uart_unregister_proto(struct hci_uart_proto *p)
  67 {
  68         if (p->id >= HCI_UART_MAX_PROTO)
  69                 return -EINVAL;
  70
  71         if (!hup[p->id])
  72                 return -EINVAL;
  73
  74         hup[p->id] = NULL;
  75
  76         return 0;
  77 }
  78
  79 static struct hci_uart_proto *hci_uart_get_proto(unsigned int id)
  80 {
  81         if (id >= HCI_UART_MAX_PROTO)
  82                 return NULL;
  83
  84         return hup[id];
  85 }
  86
  87 static inline void hci_uart_tx_complete(struct hci_uart *hu, int pkt_type)
  88 {
  89         struct hci_dev *hdev = hu->hdev;
  90
  91         /* Update HCI stat counters */
  92         switch (pkt_type) {
  93         case HCI_COMMAND_PKT:
  94                 hdev->stat.cmd_tx++;
  95                 break;
  96
  97         case HCI_ACLDATA_PKT:
  98                 hdev->stat.acl_tx++;
  99                 break;
 100
 101         case HCI_SCODATA_PKT:
 102                 hdev->stat.sco_tx++;
 103                 break;
 104         }
 105 }
 106
 107 static inline struct sk_buff *hci_uart_dequeue(struct hci_uart *hu)
 108 {
 109         struct sk_buff *skb = hu->tx_skb;
 110
 111         if (!skb)
 112                 skb = hu->proto->dequeue(hu);
 113         else
 114                 hu->tx_skb = NULL;
 115
 116         return skb;
 117 }
 118
 119 int hci_uart_tx_wakeup(struct hci_uart *hu)
 120 {
 121         if (test_and_set_bit(HCI_UART_SENDING, &hu->tx_state)) {
 122                 set_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
 123                 return 0;
 124         }
 125
 126         BT_DBG("");
 127
 128         schedule_work(&hu->write_work);
 129
 130         return 0;
 131 }
 132
 133 static void hci_uart_write_work(struct work_struct *work)
 134 {
 135         struct hci_uart *hu = container_of(work, struct hci_uart, write_work);
 136         struct tty_struct *tty = hu->tty;
 137         struct hci_dev *hdev = hu->hdev;
 138         struct sk_buff *skb;
 139
 140         /* REVISIT: should we cope with bad skbs or ->write() returning
 141          * and error value ?
 142          */
 143
 144 restart:
 145         clear_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
 146
 147         while ((skb = hci_uart_dequeue(hu))) {
 148                 int len;
 149
 150                 set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
 151                 len = tty->ops->write(tty, skb->data, skb->len);
 152                 hdev->stat.byte_tx += len;
 153
 154                 skb_pull(skb, len);
 155                 if (skb->len) {
 156                         hu->tx_skb = skb;
 157                         break;
 158                 }
 159
 160                 hci_uart_tx_complete(hu, bt_cb(skb)->pkt_type);
 161                 kfree_skb(skb);
 162         }
 163
 164         if (test_bit(HCI_UART_TX_WAKEUP, &hu->tx_state))
 165                 goto restart;
 166
 167         clear_bit(HCI_UART_SENDING, &hu->tx_state);
 168 }
 169
 170 static void hci_uart_init_work(struct work_struct *work)
 171 {
 172         struct hci_uart *hu = container_of(work, struct hci_uart, init_ready);
 173         int err;
 174
 175         if (!test_and_clear_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
 176                 return;
 177
 178         err = hci_register_dev(hu->hdev);
 179         if (err < 0) {
 180                 BT_ERR("Can't register HCI device");
 181                 hci_free_dev(hu->hdev);
 182                 hu->hdev = NULL;
 183                 hu->proto->close(hu);
 184         }
 185
 186         set_bit(HCI_UART_REGISTERED, &hu->flags);
 187 }
 188
 189 int hci_uart_init_ready(struct hci_uart *hu)
 190 {
 191         if (!test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
 192                 return -EALREADY;
 193
 194         schedule_work(&hu->init_ready);
 195
 196         return 0;
 197 }
 198
 199 /* ------- Interface to HCI layer ------ */
 200 /* Initialize device */
 201 static int hci_uart_open(struct hci_dev *hdev)
 202 {
 203         BT_DBG("%s %p", hdev->name, hdev);
 204
 205         /* Nothing to do for UART driver */
 206
 207         set_bit(HCI_RUNNING, &hdev->flags);
 208
 209         return 0;
 210 }
 211
 212 /* Reset device */
 213 static int hci_uart_flush(struct hci_dev *hdev)
 214 {
 215         struct hci_uart *hu  = hci_get_drvdata(hdev);
 216         struct tty_struct *tty = hu->tty;
 217
 218         BT_DBG("hdev %p tty %p", hdev, tty);
 219
 220         if (hu->tx_skb) {
 221                 kfree_skb(hu->tx_skb); hu->tx_skb = NULL;
 222         }
 223
 224         /* Flush any pending characters in the driver and discipline. */
 225         tty_ldisc_flush(tty);
 226         tty_driver_flush_buffer(tty);
 227
 228         if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
 229                 hu->proto->flush(hu);
 230
 231         return 0;
 232 }
 233
 234 /* Close device */
 235 static int hci_uart_close(struct hci_dev *hdev)
 236 {
 237         BT_DBG("hdev %p", hdev);
 238
 239         if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags))
 240                 return 0;
 241
 242         hci_uart_flush(hdev);
 243         hdev->flush = NULL;
 244         return 0;
 245 }
 246
 247 /* Send frames from HCI layer */
 248 static int hci_uart_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
 249 {
 250         struct hci_uart *hu = hci_get_drvdata(hdev);
 251
 252         if (!test_bit(HCI_RUNNING, &hdev->flags))
 253                 return -EBUSY;
 254
 255         BT_DBG("%s: type %d len %d", hdev->name, bt_cb(skb)->pkt_type, skb->len);
 256
 257         hu->proto->enqueue(hu, skb);
 258
 259         hci_uart_tx_wakeup(hu);
 260
 261         return 0;
 262 }
 263
 264 static int hci_uart_setup(struct hci_dev *hdev)
 265 {
 266         struct hci_uart *hu = hci_get_drvdata(hdev);
 267         struct hci_rp_read_local_version *ver;
 268         struct sk_buff *skb;
 269
 270         if (hu->proto->setup)
 271                 return hu->proto->setup(hu);
 272
 273         if (!test_bit(HCI_UART_VND_DETECT, &hu->hdev_flags))
 274                 return 0;
 275
 276         skb = __hci_cmd_sync(hdev, HCI_OP_READ_LOCAL_VERSION, 0, NULL,
 277                              HCI_INIT_TIMEOUT);
 278         if (IS_ERR(skb)) {
 279                 BT_ERR("%s: Reading local version information failed (%ld)",
 280                        hdev->name, PTR_ERR(skb));
 281                 return 0;
 282         }
 283
 284         if (skb->len != sizeof(*ver)) {
 285                 BT_ERR("%s: Event length mismatch for version information",
 286                        hdev->name);
 287                 goto done;
 288         }
 289
 290         ver = (struct hci_rp_read_local_version *)skb->data;
 291
 292         switch (le16_to_cpu(ver->manufacturer)) {
 293 #ifdef CONFIG_BT_HCIUART_INTEL
 294         case 2:
 295                 hdev->set_bdaddr = intel_set_bdaddr;
 296                 break;
 297 #endif
 298 #ifdef CONFIG_BT_HCIUART_BCM
 299         case 15:
 300                 hdev->set_bdaddr = bcm_set_bdaddr;
 301                 break;
 302 #endif
 303         }
 304
 305 done:
 306         kfree_skb(skb);
 307         return 0;
 308 }
 309
 310 /* ------ LDISC part ------ */
 311 /* hci_uart_tty_open
 312  *
 313  *     Called when line discipline changed to HCI_UART.
 314  *
 315  * Arguments:
 316  *     tty    pointer to tty info structure
 317  * Return Value:
 318  *     0 if success, otherwise error code
 319  */
 320 static int hci_uart_tty_open(struct tty_struct *tty)
 321 {
 322         struct hci_uart *hu;
 323
 324         BT_DBG("tty %p", tty);
 325
 326         /* Error if the tty has no write op instead of leaving an exploitable
 327            hole */
 328         if (tty->ops->write == NULL)
 329                 return -EOPNOTSUPP;
 330
 331         hu = kzalloc(sizeof(struct hci_uart), GFP_KERNEL);
 332         if (!hu) {
 333                 BT_ERR("Can't allocate control structure");
 334                 return -ENFILE;
 335         }
 336
 337         tty->disc_data = hu;
 338         hu->tty = tty;
 339         tty->receive_room = 65536;
 340
 341         INIT_WORK(&hu->init_ready, hci_uart_init_work);
 342         INIT_WORK(&hu->write_work, hci_uart_write_work);
 343
 344         spin_lock_init(&hu->rx_lock);
 345
 346         /* Flush any pending characters in the driver and line discipline. */
 347
 348         /* FIXME: why is this needed. Note don't use ldisc_ref here as the
 349            open path is before the ldisc is referencable */
 350
 351         if (tty->ldisc->ops->flush_buffer)
 352                 tty->ldisc->ops->flush_buffer(tty);
 353         tty_driver_flush_buffer(tty);
 354
 355         return 0;
 356 }
 357
 358 /* hci_uart_tty_close()
 359  *
 360  *    Called when the line discipline is changed to something
 361  *    else, the tty is closed, or the tty detects a hangup.
 362  */
 363 static void hci_uart_tty_close(struct tty_struct *tty)
 364 {
 365         struct hci_uart *hu = tty->disc_data;
 366         struct hci_dev *hdev;
 367
 368         BT_DBG("tty %p", tty);
 369
 370         /* Detach from the tty */
 371         tty->disc_data = NULL;
 372
 373         if (!hu)
 374                 return;
 375
 376         hdev = hu->hdev;
 377         if (hdev)
 378                 hci_uart_close(hdev);
 379
 380         cancel_work_sync(&hu->write_work);
 381
 382         if (test_and_clear_bit(HCI_UART_PROTO_SET, &hu->flags)) {
 383                 if (hdev) {
 384                         if (test_bit(HCI_UART_REGISTERED, &hu->flags))
 385                                 hci_unregister_dev(hdev);
 386                         hci_free_dev(hdev);
 387                 }
 388                 hu->proto->close(hu);
 389         }
 390
 391         kfree(hu);
 392 }
 393
 394 /* hci_uart_tty_wakeup()
 395  *
 396  *    Callback for transmit wakeup. Called when low level
 397  *    device driver can accept more send data.
 398  *
 399  * Arguments:        tty    pointer to associated tty instance data
 400  * Return Value:    None
 401  */
 402 static void hci_uart_tty_wakeup(struct tty_struct *tty)
 403 {
 404         struct hci_uart *hu = tty->disc_data;
 405
 406         BT_DBG("");
 407
 408         if (!hu)
 409                 return;
 410
 411         clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
 412
 413         if (tty != hu->tty)
 414                 return;
 415
 416         if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
 417                 hci_uart_tx_wakeup(hu);
 418 }
 419
 420 /* hci_uart_tty_receive()
 421  *
 422  *     Called by tty low level driver when receive data is
 423  *     available.
 424  *
 425  * Arguments:  tty          pointer to tty isntance data
 426  *             data         pointer to received data
 427  *             flags        pointer to flags for data
 428  *             count        count of received data in bytes
 429  *
 430  * Return Value:    None
 431  */
 432 static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data,
 433                                  char *flags, int count)
 434 {
 435         struct hci_uart *hu = tty->disc_data;
 436
 437         if (!hu || tty != hu->tty)
 438                 return;
 439
 440         if (!test_bit(HCI_UART_PROTO_SET, &hu->flags))
 441                 return;
 442
 443         spin_lock(&hu->rx_lock);
 444         hu->proto->recv(hu, data, count);
 445
 446         if (hu->hdev)
 447                 hu->hdev->stat.byte_rx += count;
 448
 449         spin_unlock(&hu->rx_lock);
 450
 451         tty_unthrottle(tty);
 452 }
 453
 454 static int hci_uart_register_dev(struct hci_uart *hu)
 455 {
 456         struct hci_dev *hdev;
 457
 458         BT_DBG("");
 459
 460         /* Initialize and register HCI device */
 461         hdev = hci_alloc_dev();
 462         if (!hdev) {
 463                 BT_ERR("Can't allocate HCI device");
 464                 return -ENOMEM;
 465         }
 466
 467         hu->hdev = hdev;
 468
 469         hdev->bus = HCI_UART;
 470         hci_set_drvdata(hdev, hu);
 471
 472         hdev->open  = hci_uart_open;
 473         hdev->close = hci_uart_close;
 474         hdev->flush = hci_uart_flush;
 475         hdev->send  = hci_uart_send_frame;
 476         hdev->setup = hci_uart_setup;
 477         SET_HCIDEV_DEV(hdev, hu->tty->dev);
 478
 479         if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags))
 480                 set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
 481
 482         if (test_bit(HCI_UART_EXT_CONFIG, &hu->hdev_flags))
 483                 set_bit(HCI_QUIRK_EXTERNAL_CONFIG, &hdev->quirks);
 484
 485         if (!test_bit(HCI_UART_RESET_ON_INIT, &hu->hdev_flags))
 486                 set_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks);
 487
 488         if (test_bit(HCI_UART_CREATE_AMP, &hu->hdev_flags))
 489                 hdev->dev_type = HCI_AMP;
 490         else
 491                 hdev->dev_type = HCI_BREDR;
 492
 493         if (test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
 494                 return 0;
 495
 496         if (hci_register_dev(hdev) < 0) {
 497                 BT_ERR("Can't register HCI device");
 498                 hci_free_dev(hdev);
 499                 return -ENODEV;
 500         }
 501
 502         set_bit(HCI_UART_REGISTERED, &hu->flags);
 503
 504         return 0;
 505 }
 506
 507 static int hci_uart_set_proto(struct hci_uart *hu, int id)
 508 {
 509         struct hci_uart_proto *p;
 510         int err;
 511
 512         p = hci_uart_get_proto(id);
 513         if (!p)
 514                 return -EPROTONOSUPPORT;
 515
 516         err = p->open(hu);
 517         if (err)
 518                 return err;
 519
 520         hu->proto = p;
 521
 522         err = hci_uart_register_dev(hu);
 523         if (err) {
 524                 p->close(hu);
 525                 return err;
 526         }
 527
 528         return 0;
 529 }
 530
 531 static int hci_uart_set_flags(struct hci_uart *hu, unsigned long flags)
 532 {
 533         unsigned long valid_flags = BIT(HCI_UART_RAW_DEVICE) |
 534                                     BIT(HCI_UART_RESET_ON_INIT) |
 535                                     BIT(HCI_UART_CREATE_AMP) |
 536                                     BIT(HCI_UART_INIT_PENDING) |
 537                                     BIT(HCI_UART_EXT_CONFIG) |
 538                                     BIT(HCI_UART_VND_DETECT);
 539
 540         if (flags & ~valid_flags)
 541                 return -EINVAL;
 542
 543         hu->hdev_flags = flags;
 544
 545         return 0;
 546 }
 547
 548 /* hci_uart_tty_ioctl()
 549  *
 550  *    Process IOCTL system call for the tty device.
 551  *
 552  * Arguments:
 553  *
 554  *    tty        pointer to tty instance data
 555  *    file       pointer to open file object for device
 556  *    cmd        IOCTL command code
 557  *    arg        argument for IOCTL call (cmd dependent)
 558  *
 559  * Return Value:    Command dependent
 560  */
 561 static int hci_uart_tty_ioctl(struct tty_struct *tty, struct file *file,
 562                               unsigned int cmd, unsigned long arg)
 563 {
 564         struct hci_uart *hu = tty->disc_data;
 565         int err = 0;
 566
 567         BT_DBG("");
 568
 569         /* Verify the status of the device */
 570         if (!hu)
 571                 return -EBADF;
 572
 573         switch (cmd) {
 574         case HCIUARTSETPROTO:
 575                 if (!test_and_set_bit(HCI_UART_PROTO_SET, &hu->flags)) {
 576                         err = hci_uart_set_proto(hu, arg);
 577                         if (err) {
 578                                 clear_bit(HCI_UART_PROTO_SET, &hu->flags);
 579                                 return err;
 580                         }
 581                 } else
 582                         return -EBUSY;
 583                 break;
 584
 585         case HCIUARTGETPROTO:
 586                 if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
 587                         return hu->proto->id;
 588                 return -EUNATCH;
 589
 590         case HCIUARTGETDEVICE:
 591                 if (test_bit(HCI_UART_REGISTERED, &hu->flags))
 592                         return hu->hdev->id;
 593                 return -EUNATCH;
 594
 595         case HCIUARTSETFLAGS:
 596                 if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
 597                         return -EBUSY;
 598                 err = hci_uart_set_flags(hu, arg);
 599                 if (err)
 600                         return err;
 601                 break;
 602
 603         case HCIUARTGETFLAGS:
 604                 return hu->hdev_flags;
 605
 606         default:
 607                 err = n_tty_ioctl_helper(tty, file, cmd, arg);
 608                 break;
 609         }
 610
 611         return err;
 612 }
 613
 614 /*
 615  * We don't provide read/write/poll interface for user space.
 616  */
 617 static ssize_t hci_uart_tty_read(struct tty_struct *tty, struct file *file,
 618                                  unsigned char __user *buf, size_t nr)
 619 {
 620         return 0;
 621 }
 622
 623 static ssize_t hci_uart_tty_write(struct tty_struct *tty, struct file *file,
 624                                   const unsigned char *data, size_t count)
 625 {
 626         return 0;
 627 }
 628
 629 static unsigned int hci_uart_tty_poll(struct tty_struct *tty,
 630                                       struct file *filp, poll_table *wait)
 631 {
 632         return 0;
 633 }
 634
 635 static int __init hci_uart_init(void)
 636 {
 637         static struct tty_ldisc_ops hci_uart_ldisc;
 638         int err;
 639
 640         BT_INFO("HCI UART driver ver %s", VERSION);
 641
 642         /* Register the tty discipline */
 643
 644         memset(&hci_uart_ldisc, 0, sizeof (hci_uart_ldisc));
 645         hci_uart_ldisc.magic            = TTY_LDISC_MAGIC;
 646         hci_uart_ldisc.name             = "n_hci";
 647         hci_uart_ldisc.open             = hci_uart_tty_open;
 648         hci_uart_ldisc.close            = hci_uart_tty_close;
 649         hci_uart_ldisc.read             = hci_uart_tty_read;
 650         hci_uart_ldisc.write            = hci_uart_tty_write;
 651         hci_uart_ldisc.ioctl            = hci_uart_tty_ioctl;
 652         hci_uart_ldisc.poll             = hci_uart_tty_poll;
 653         hci_uart_ldisc.receive_buf      = hci_uart_tty_receive;
 654         hci_uart_ldisc.write_wakeup     = hci_uart_tty_wakeup;
 655         hci_uart_ldisc.owner            = THIS_MODULE;
 656
 657         err = tty_register_ldisc(N_HCI, &hci_uart_ldisc);
 658         if (err) {
 659                 BT_ERR("HCI line discipline registration failed. (%d)", err);
 660                 return err;
 661         }
 662
 663 #ifdef CONFIG_BT_HCIUART_H4
 664         h4_init();
 665 #endif
 666 #ifdef CONFIG_BT_HCIUART_BCSP
 667         bcsp_init();
 668 #endif
 669 #ifdef CONFIG_BT_HCIUART_LL
 670         ll_init();
 671 #endif
 672 #ifdef CONFIG_BT_HCIUART_ATH3K
 673         ath_init();
 674 #endif
 675 #ifdef CONFIG_BT_HCIUART_3WIRE
 676         h5_init();
 677 #endif
 678
 679         return 0;
 680 }
 681
 682 static void __exit hci_uart_exit(void)
 683 {
 684         int err;
 685
 686 #ifdef CONFIG_BT_HCIUART_H4
 687         h4_deinit();
 688 #endif
 689 #ifdef CONFIG_BT_HCIUART_BCSP
 690         bcsp_deinit();
 691 #endif
 692 #ifdef CONFIG_BT_HCIUART_LL
 693         ll_deinit();
 694 #endif
 695 #ifdef CONFIG_BT_HCIUART_ATH3K
 696         ath_deinit();
 697 #endif
 698 #ifdef CONFIG_BT_HCIUART_3WIRE
 699         h5_deinit();
 700 #endif
 701
 702         /* Release tty registration of line discipline */
 703         err = tty_unregister_ldisc(N_HCI);
 704         if (err)
 705                 BT_ERR("Can't unregister HCI line discipline (%d)", err);
 706 }
 707
 708 module_init(hci_uart_init);
 709 module_exit(hci_uart_exit);
 710
 711 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
 712 MODULE_DESCRIPTION("Bluetooth HCI UART driver ver " VERSION);
 713 MODULE_VERSION(VERSION);
 714 MODULE_LICENSE("GPL");
 715 MODULE_ALIAS_LDISC(N_HCI);