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 "btbcm.h"
  48 #include "hci_uart.h"
  49
  50 #define VERSION "2.3"
  51
  52 static const struct hci_uart_proto *hup[HCI_UART_MAX_PROTO];
  53
  54 int hci_uart_register_proto(const struct hci_uart_proto *p)
  55 {
  56         if (p->id >= HCI_UART_MAX_PROTO)
  57                 return -EINVAL;
  58
  59         if (hup[p->id])
  60                 return -EEXIST;
  61
  62         hup[p->id] = p;
  63
  64         BT_INFO("HCI UART protocol %s registered", p->name);
  65
  66         return 0;
  67 }
  68
  69 int hci_uart_unregister_proto(const struct hci_uart_proto *p)
  70 {
  71         if (p->id >= HCI_UART_MAX_PROTO)
  72                 return -EINVAL;
  73
  74         if (!hup[p->id])
  75                 return -EINVAL;
  76
  77         hup[p->id] = NULL;
  78
  79         return 0;
  80 }
  81
  82 static const struct hci_uart_proto *hci_uart_get_proto(unsigned int id)
  83 {
  84         if (id >= HCI_UART_MAX_PROTO)
  85                 return NULL;
  86
  87         return hup[id];
  88 }
  89
  90 static inline void hci_uart_tx_complete(struct hci_uart *hu, int pkt_type)
  91 {
  92         struct hci_dev *hdev = hu->hdev;
  93
  94         /* Update HCI stat counters */
  95         switch (pkt_type) {
  96         case HCI_COMMAND_PKT:
  97                 hdev->stat.cmd_tx++;
  98                 break;
  99
 100         case HCI_ACLDATA_PKT:
 101                 hdev->stat.acl_tx++;
 102                 break;
 103
 104         case HCI_SCODATA_PKT:
 105                 hdev->stat.sco_tx++;
 106                 break;
 107         }
 108 }
 109
 110 static inline struct sk_buff *hci_uart_dequeue(struct hci_uart *hu)
 111 {
 112         struct sk_buff *skb = hu->tx_skb;
 113
 114         if (!skb)
 115                 skb = hu->proto->dequeue(hu);
 116         else
 117                 hu->tx_skb = NULL;
 118
 119         return skb;
 120 }
 121
 122 int hci_uart_tx_wakeup(struct hci_uart *hu)
 123 {
 124         if (test_and_set_bit(HCI_UART_SENDING, &hu->tx_state)) {
 125                 set_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
 126                 return 0;
 127         }
 128
 129         BT_DBG("");
 130
 131         schedule_work(&hu->write_work);
 132
 133         return 0;
 134 }
 135
 136 static void hci_uart_write_work(struct work_struct *work)
 137 {
 138         struct hci_uart *hu = container_of(work, struct hci_uart, write_work);
 139         struct tty_struct *tty = hu->tty;
 140         struct hci_dev *hdev = hu->hdev;
 141         struct sk_buff *skb;
 142
 143         /* REVISIT: should we cope with bad skbs or ->write() returning
 144          * and error value ?
 145          */
 146
 147 restart:
 148         clear_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
 149
 150         while ((skb = hci_uart_dequeue(hu))) {
 151                 int len;
 152
 153                 set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
 154                 len = tty->ops->write(tty, skb->data, skb->len);
 155                 hdev->stat.byte_tx += len;
 156
 157                 skb_pull(skb, len);
 158                 if (skb->len) {
 159                         hu->tx_skb = skb;
 160                         break;
 161                 }
 162
 163                 hci_uart_tx_complete(hu, bt_cb(skb)->pkt_type);
 164                 kfree_skb(skb);
 165         }
 166
 167         if (test_bit(HCI_UART_TX_WAKEUP, &hu->tx_state))
 168                 goto restart;
 169
 170         clear_bit(HCI_UART_SENDING, &hu->tx_state);
 171 }
 172
 173 static void hci_uart_init_work(struct work_struct *work)
 174 {
 175         struct hci_uart *hu = container_of(work, struct hci_uart, init_ready);
 176         int err;
 177
 178         if (!test_and_clear_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
 179                 return;
 180
 181         err = hci_register_dev(hu->hdev);
 182         if (err < 0) {
 183                 BT_ERR("Can't register HCI device");
 184                 hci_free_dev(hu->hdev);
 185                 hu->hdev = NULL;
 186                 hu->proto->close(hu);
 187         }
 188
 189         set_bit(HCI_UART_REGISTERED, &hu->flags);
 190 }
 191
 192 int hci_uart_init_ready(struct hci_uart *hu)
 193 {
 194         if (!test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
 195                 return -EALREADY;
 196
 197         schedule_work(&hu->init_ready);
 198
 199         return 0;
 200 }
 201
 202 /* ------- Interface to HCI layer ------ */
 203 /* Initialize device */
 204 static int hci_uart_open(struct hci_dev *hdev)
 205 {
 206         BT_DBG("%s %p", hdev->name, hdev);
 207
 208         /* Nothing to do for UART driver */
 209
 210         set_bit(HCI_RUNNING, &hdev->flags);
 211
 212         return 0;
 213 }
 214
 215 /* Reset device */
 216 static int hci_uart_flush(struct hci_dev *hdev)
 217 {
 218         struct hci_uart *hu  = hci_get_drvdata(hdev);
 219         struct tty_struct *tty = hu->tty;
 220
 221         BT_DBG("hdev %p tty %p", hdev, tty);
 222
 223         if (hu->tx_skb) {
 224                 kfree_skb(hu->tx_skb); hu->tx_skb = NULL;
 225         }
 226
 227         /* Flush any pending characters in the driver and discipline. */
 228         tty_ldisc_flush(tty);
 229         tty_driver_flush_buffer(tty);
 230
 231         if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
 232                 hu->proto->flush(hu);
 233
 234         return 0;
 235 }
 236
 237 /* Close device */
 238 static int hci_uart_close(struct hci_dev *hdev)
 239 {
 240         BT_DBG("hdev %p", hdev);
 241
 242         if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags))
 243                 return 0;
 244
 245         hci_uart_flush(hdev);
 246         hdev->flush = NULL;
 247         return 0;
 248 }
 249
 250 /* Send frames from HCI layer */
 251 static int hci_uart_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
 252 {
 253         struct hci_uart *hu = hci_get_drvdata(hdev);
 254
 255         if (!test_bit(HCI_RUNNING, &hdev->flags))
 256                 return -EBUSY;
 257
 258         BT_DBG("%s: type %d len %d", hdev->name, bt_cb(skb)->pkt_type, skb->len);
 259
 260         hu->proto->enqueue(hu, skb);
 261
 262         hci_uart_tx_wakeup(hu);
 263
 264         return 0;
 265 }
 266
 267 static int hci_uart_setup(struct hci_dev *hdev)
 268 {
 269         struct hci_uart *hu = hci_get_drvdata(hdev);
 270         struct hci_rp_read_local_version *ver;
 271         struct sk_buff *skb;
 272
 273         if (hu->proto->setup)
 274                 return hu->proto->setup(hu);
 275
 276         if (!test_bit(HCI_UART_VND_DETECT, &hu->hdev_flags))
 277                 return 0;
 278
 279         skb = __hci_cmd_sync(hdev, HCI_OP_READ_LOCAL_VERSION, 0, NULL,
 280                              HCI_INIT_TIMEOUT);
 281         if (IS_ERR(skb)) {
 282                 BT_ERR("%s: Reading local version information failed (%ld)",
 283                        hdev->name, PTR_ERR(skb));
 284                 return 0;
 285         }
 286
 287         if (skb->len != sizeof(*ver)) {
 288                 BT_ERR("%s: Event length mismatch for version information",
 289                        hdev->name);
 290                 goto done;
 291         }
 292
 293         ver = (struct hci_rp_read_local_version *)skb->data;
 294
 295         switch (le16_to_cpu(ver->manufacturer)) {
 296 #ifdef CONFIG_BT_HCIUART_INTEL
 297         case 2:
 298                 hdev->set_bdaddr = intel_set_bdaddr;
 299                 break;
 300 #endif
 301 #ifdef CONFIG_BT_HCIUART_BCM
 302         case 15:
 303                 hdev->set_bdaddr = btbcm_set_bdaddr;
 304                 btbcm_check_bdaddr(hdev);
 305                 break;
 306 #endif
 307         }
 308
 309 done:
 310         kfree_skb(skb);
 311         return 0;
 312 }
 313
 314 /* ------ LDISC part ------ */
 315 /* hci_uart_tty_open
 316  *
 317  *     Called when line discipline changed to HCI_UART.
 318  *
 319  * Arguments:
 320  *     tty    pointer to tty info structure
 321  * Return Value:
 322  *     0 if success, otherwise error code
 323  */
 324 static int hci_uart_tty_open(struct tty_struct *tty)
 325 {
 326         struct hci_uart *hu;
 327
 328         BT_DBG("tty %p", tty);
 329
 330         /* Error if the tty has no write op instead of leaving an exploitable
 331            hole */
 332         if (tty->ops->write == NULL)
 333                 return -EOPNOTSUPP;
 334
 335         hu = kzalloc(sizeof(struct hci_uart), GFP_KERNEL);
 336         if (!hu) {
 337                 BT_ERR("Can't allocate control structure");
 338                 return -ENFILE;
 339         }
 340
 341         tty->disc_data = hu;
 342         hu->tty = tty;
 343         tty->receive_room = 65536;
 344
 345         INIT_WORK(&hu->init_ready, hci_uart_init_work);
 346         INIT_WORK(&hu->write_work, hci_uart_write_work);
 347
 348         spin_lock_init(&hu->rx_lock);
 349
 350         /* Flush any pending characters in the driver and line discipline. */
 351
 352         /* FIXME: why is this needed. Note don't use ldisc_ref here as the
 353            open path is before the ldisc is referencable */
 354
 355         if (tty->ldisc->ops->flush_buffer)
 356                 tty->ldisc->ops->flush_buffer(tty);
 357         tty_driver_flush_buffer(tty);
 358
 359         return 0;
 360 }
 361
 362 /* hci_uart_tty_close()
 363  *
 364  *    Called when the line discipline is changed to something
 365  *    else, the tty is closed, or the tty detects a hangup.
 366  */
 367 static void hci_uart_tty_close(struct tty_struct *tty)
 368 {
 369         struct hci_uart *hu = tty->disc_data;
 370         struct hci_dev *hdev;
 371
 372         BT_DBG("tty %p", tty);
 373
 374         /* Detach from the tty */
 375         tty->disc_data = NULL;
 376
 377         if (!hu)
 378                 return;
 379
 380         hdev = hu->hdev;
 381         if (hdev)
 382                 hci_uart_close(hdev);
 383
 384         cancel_work_sync(&hu->write_work);
 385
 386         if (test_and_clear_bit(HCI_UART_PROTO_SET, &hu->flags)) {
 387                 if (hdev) {
 388                         if (test_bit(HCI_UART_REGISTERED, &hu->flags))
 389                                 hci_unregister_dev(hdev);
 390                         hci_free_dev(hdev);
 391                 }
 392                 hu->proto->close(hu);
 393         }
 394
 395         kfree(hu);
 396 }
 397
 398 /* hci_uart_tty_wakeup()
 399  *
 400  *    Callback for transmit wakeup. Called when low level
 401  *    device driver can accept more send data.
 402  *
 403  * Arguments:        tty    pointer to associated tty instance data
 404  * Return Value:    None
 405  */
 406 static void hci_uart_tty_wakeup(struct tty_struct *tty)
 407 {
 408         struct hci_uart *hu = tty->disc_data;
 409
 410         BT_DBG("");
 411
 412         if (!hu)
 413                 return;
 414
 415         clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
 416
 417         if (tty != hu->tty)
 418                 return;
 419
 420         if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
 421                 hci_uart_tx_wakeup(hu);
 422 }
 423
 424 /* hci_uart_tty_receive()
 425  *
 426  *     Called by tty low level driver when receive data is
 427  *     available.
 428  *
 429  * Arguments:  tty          pointer to tty isntance data
 430  *             data         pointer to received data
 431  *             flags        pointer to flags for data
 432  *             count        count of received data in bytes
 433  *
 434  * Return Value:    None
 435  */
 436 static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data,
 437                                  char *flags, int count)
 438 {
 439         struct hci_uart *hu = tty->disc_data;
 440
 441         if (!hu || tty != hu->tty)
 442                 return;
 443
 444         if (!test_bit(HCI_UART_PROTO_SET, &hu->flags))
 445                 return;
 446
 447         spin_lock(&hu->rx_lock);
 448         hu->proto->recv(hu, data, count);
 449
 450         if (hu->hdev)
 451                 hu->hdev->stat.byte_rx += count;
 452
 453         spin_unlock(&hu->rx_lock);
 454
 455         tty_unthrottle(tty);
 456 }
 457
 458 static int hci_uart_register_dev(struct hci_uart *hu)
 459 {
 460         struct hci_dev *hdev;
 461
 462         BT_DBG("");
 463
 464         /* Initialize and register HCI device */
 465         hdev = hci_alloc_dev();
 466         if (!hdev) {
 467                 BT_ERR("Can't allocate HCI device");
 468                 return -ENOMEM;
 469         }
 470
 471         hu->hdev = hdev;
 472
 473         hdev->bus = HCI_UART;
 474         hci_set_drvdata(hdev, hu);
 475
 476         hdev->open  = hci_uart_open;
 477         hdev->close = hci_uart_close;
 478         hdev->flush = hci_uart_flush;
 479         hdev->send  = hci_uart_send_frame;
 480         hdev->setup = hci_uart_setup;
 481         SET_HCIDEV_DEV(hdev, hu->tty->dev);
 482
 483         if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags))
 484                 set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
 485
 486         if (test_bit(HCI_UART_EXT_CONFIG, &hu->hdev_flags))
 487                 set_bit(HCI_QUIRK_EXTERNAL_CONFIG, &hdev->quirks);
 488
 489         if (!test_bit(HCI_UART_RESET_ON_INIT, &hu->hdev_flags))
 490                 set_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks);
 491
 492         if (test_bit(HCI_UART_CREATE_AMP, &hu->hdev_flags))
 493                 hdev->dev_type = HCI_AMP;
 494         else
 495                 hdev->dev_type = HCI_BREDR;
 496
 497         if (test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
 498                 return 0;
 499
 500         if (hci_register_dev(hdev) < 0) {
 501                 BT_ERR("Can't register HCI device");
 502                 hci_free_dev(hdev);
 503                 return -ENODEV;
 504         }
 505
 506         set_bit(HCI_UART_REGISTERED, &hu->flags);
 507
 508         return 0;
 509 }
 510
 511 static int hci_uart_set_proto(struct hci_uart *hu, int id)
 512 {
 513         const struct hci_uart_proto *p;
 514         int err;
 515
 516         p = hci_uart_get_proto(id);
 517         if (!p)
 518                 return -EPROTONOSUPPORT;
 519
 520         err = p->open(hu);
 521         if (err)
 522                 return err;
 523
 524         hu->proto = p;
 525
 526         err = hci_uart_register_dev(hu);
 527         if (err) {
 528                 p->close(hu);
 529                 return err;
 530         }
 531
 532         return 0;
 533 }
 534
 535 static int hci_uart_set_flags(struct hci_uart *hu, unsigned long flags)
 536 {
 537         unsigned long valid_flags = BIT(HCI_UART_RAW_DEVICE) |
 538                                     BIT(HCI_UART_RESET_ON_INIT) |
 539                                     BIT(HCI_UART_CREATE_AMP) |
 540                                     BIT(HCI_UART_INIT_PENDING) |
 541                                     BIT(HCI_UART_EXT_CONFIG) |
 542                                     BIT(HCI_UART_VND_DETECT);
 543
 544         if (flags & ~valid_flags)
 545                 return -EINVAL;
 546
 547         hu->hdev_flags = flags;
 548
 549         return 0;
 550 }
 551
 552 /* hci_uart_tty_ioctl()
 553  *
 554  *    Process IOCTL system call for the tty device.
 555  *
 556  * Arguments:
 557  *
 558  *    tty        pointer to tty instance data
 559  *    file       pointer to open file object for device
 560  *    cmd        IOCTL command code
 561  *    arg        argument for IOCTL call (cmd dependent)
 562  *
 563  * Return Value:    Command dependent
 564  */
 565 static int hci_uart_tty_ioctl(struct tty_struct *tty, struct file *file,
 566                               unsigned int cmd, unsigned long arg)
 567 {
 568         struct hci_uart *hu = tty->disc_data;
 569         int err = 0;
 570
 571         BT_DBG("");
 572
 573         /* Verify the status of the device */
 574         if (!hu)
 575                 return -EBADF;
 576
 577         switch (cmd) {
 578         case HCIUARTSETPROTO:
 579                 if (!test_and_set_bit(HCI_UART_PROTO_SET, &hu->flags)) {
 580                         err = hci_uart_set_proto(hu, arg);
 581                         if (err) {
 582                                 clear_bit(HCI_UART_PROTO_SET, &hu->flags);
 583                                 return err;
 584                         }
 585                 } else
 586                         return -EBUSY;
 587                 break;
 588
 589         case HCIUARTGETPROTO:
 590                 if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
 591                         return hu->proto->id;
 592                 return -EUNATCH;
 593
 594         case HCIUARTGETDEVICE:
 595                 if (test_bit(HCI_UART_REGISTERED, &hu->flags))
 596                         return hu->hdev->id;
 597                 return -EUNATCH;
 598
 599         case HCIUARTSETFLAGS:
 600                 if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
 601                         return -EBUSY;
 602                 err = hci_uart_set_flags(hu, arg);
 603                 if (err)
 604                         return err;
 605                 break;
 606
 607         case HCIUARTGETFLAGS:
 608                 return hu->hdev_flags;
 609
 610         default:
 611                 err = n_tty_ioctl_helper(tty, file, cmd, arg);
 612                 break;
 613         }
 614
 615         return err;
 616 }
 617
 618 /*
 619  * We don't provide read/write/poll interface for user space.
 620  */
 621 static ssize_t hci_uart_tty_read(struct tty_struct *tty, struct file *file,
 622                                  unsigned char __user *buf, size_t nr)
 623 {
 624         return 0;
 625 }
 626
 627 static ssize_t hci_uart_tty_write(struct tty_struct *tty, struct file *file,
 628                                   const unsigned char *data, size_t count)
 629 {
 630         return 0;
 631 }
 632
 633 static unsigned int hci_uart_tty_poll(struct tty_struct *tty,
 634                                       struct file *filp, poll_table *wait)
 635 {
 636         return 0;
 637 }
 638
 639 static int __init hci_uart_init(void)
 640 {
 641         static struct tty_ldisc_ops hci_uart_ldisc;
 642         int err;
 643
 644         BT_INFO("HCI UART driver ver %s", VERSION);
 645
 646         /* Register the tty discipline */
 647
 648         memset(&hci_uart_ldisc, 0, sizeof (hci_uart_ldisc));
 649         hci_uart_ldisc.magic            = TTY_LDISC_MAGIC;
 650         hci_uart_ldisc.name             = "n_hci";
 651         hci_uart_ldisc.open             = hci_uart_tty_open;
 652         hci_uart_ldisc.close            = hci_uart_tty_close;
 653         hci_uart_ldisc.read             = hci_uart_tty_read;
 654         hci_uart_ldisc.write            = hci_uart_tty_write;
 655         hci_uart_ldisc.ioctl            = hci_uart_tty_ioctl;
 656         hci_uart_ldisc.poll             = hci_uart_tty_poll;
 657         hci_uart_ldisc.receive_buf      = hci_uart_tty_receive;
 658         hci_uart_ldisc.write_wakeup     = hci_uart_tty_wakeup;
 659         hci_uart_ldisc.owner            = THIS_MODULE;
 660
 661         err = tty_register_ldisc(N_HCI, &hci_uart_ldisc);
 662         if (err) {
 663                 BT_ERR("HCI line discipline registration failed. (%d)", err);
 664                 return err;
 665         }
 666
 667 #ifdef CONFIG_BT_HCIUART_H4
 668         h4_init();
 669 #endif
 670 #ifdef CONFIG_BT_HCIUART_BCSP
 671         bcsp_init();
 672 #endif
 673 #ifdef CONFIG_BT_HCIUART_LL
 674         ll_init();
 675 #endif
 676 #ifdef CONFIG_BT_HCIUART_ATH3K
 677         ath_init();
 678 #endif
 679 #ifdef CONFIG_BT_HCIUART_3WIRE
 680         h5_init();
 681 #endif
 682
 683         return 0;
 684 }
 685
 686 static void __exit hci_uart_exit(void)
 687 {
 688         int err;
 689
 690 #ifdef CONFIG_BT_HCIUART_H4
 691         h4_deinit();
 692 #endif
 693 #ifdef CONFIG_BT_HCIUART_BCSP
 694         bcsp_deinit();
 695 #endif
 696 #ifdef CONFIG_BT_HCIUART_LL
 697         ll_deinit();
 698 #endif
 699 #ifdef CONFIG_BT_HCIUART_ATH3K
 700         ath_deinit();
 701 #endif
 702 #ifdef CONFIG_BT_HCIUART_3WIRE
 703         h5_deinit();
 704 #endif
 705
 706         /* Release tty registration of line discipline */
 707         err = tty_unregister_ldisc(N_HCI);
 708         if (err)
 709                 BT_ERR("Can't unregister HCI line discipline (%d)", err);
 710 }
 711
 712 module_init(hci_uart_init);
 713 module_exit(hci_uart_exit);
 714
 715 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
 716 MODULE_DESCRIPTION("Bluetooth HCI UART driver ver " VERSION);
 717 MODULE_VERSION(VERSION);
 718 MODULE_LICENSE("GPL");
 719 MODULE_ALIAS_LDISC(N_HCI);