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 sk_buff *skb)
 249 {
 250         struct hci_dev* hdev = (struct hci_dev *) skb->dev;
 251         struct hci_uart *hu;
 252
 253         if (!hdev) {
 254                 BT_ERR("Frame for unknown device (hdev=NULL)");
 255                 return -ENODEV;
 256         }
 257
 258         if (!test_bit(HCI_RUNNING, &hdev->flags))
 259                 return -EBUSY;
 260
 261         hu = hci_get_drvdata(hdev);
 262
 263         BT_DBG("%s: type %d len %d", hdev->name, bt_cb(skb)->pkt_type, skb->len);
 264
 265         hu->proto->enqueue(hu, skb);
 266
 267         hci_uart_tx_wakeup(hu);
 268
 269         return 0;
 270 }
 271
 272 /* ------ LDISC part ------ */
 273 /* hci_uart_tty_open
 274  *
 275  *     Called when line discipline changed to HCI_UART.
 276  *
 277  * Arguments:
 278  *     tty    pointer to tty info structure
 279  * Return Value:
 280  *     0 if success, otherwise error code
 281  */
 282 static int hci_uart_tty_open(struct tty_struct *tty)
 283 {
 284         struct hci_uart *hu;
 285
 286         BT_DBG("tty %p", tty);
 287
 288         /* Error if the tty has no write op instead of leaving an exploitable
 289            hole */
 290         if (tty->ops->write == NULL)
 291                 return -EOPNOTSUPP;
 292
 293         if (!(hu = kzalloc(sizeof(struct hci_uart), GFP_KERNEL))) {
 294                 BT_ERR("Can't allocate control structure");
 295                 return -ENFILE;
 296         }
 297
 298         tty->disc_data = hu;
 299         hu->tty = tty;
 300         tty->receive_room = 65536;
 301
 302         INIT_WORK(&hu->init_ready, hci_uart_init_work);
 303         INIT_WORK(&hu->write_work, hci_uart_write_work);
 304
 305         spin_lock_init(&hu->rx_lock);
 306
 307         /* Flush any pending characters in the driver and line discipline. */
 308
 309         /* FIXME: why is this needed. Note don't use ldisc_ref here as the
 310            open path is before the ldisc is referencable */
 311
 312         if (tty->ldisc->ops->flush_buffer)
 313                 tty->ldisc->ops->flush_buffer(tty);
 314         tty_driver_flush_buffer(tty);
 315
 316         return 0;
 317 }
 318
 319 /* hci_uart_tty_close()
 320  *
 321  *    Called when the line discipline is changed to something
 322  *    else, the tty is closed, or the tty detects a hangup.
 323  */
 324 static void hci_uart_tty_close(struct tty_struct *tty)
 325 {
 326         struct hci_uart *hu = (void *)tty->disc_data;
 327         struct hci_dev *hdev;
 328
 329         BT_DBG("tty %p", tty);
 330
 331         /* Detach from the tty */
 332         tty->disc_data = NULL;
 333
 334         if (!hu)
 335                 return;
 336
 337         hdev = hu->hdev;
 338         if (hdev)
 339                 hci_uart_close(hdev);
 340
 341         cancel_work_sync(&hu->write_work);
 342
 343         if (test_and_clear_bit(HCI_UART_PROTO_SET, &hu->flags)) {
 344                 if (hdev) {
 345                         if (test_bit(HCI_UART_REGISTERED, &hu->flags))
 346                                 hci_unregister_dev(hdev);
 347                         hci_free_dev(hdev);
 348                 }
 349                 hu->proto->close(hu);
 350         }
 351
 352         kfree(hu);
 353 }
 354
 355 /* hci_uart_tty_wakeup()
 356  *
 357  *    Callback for transmit wakeup. Called when low level
 358  *    device driver can accept more send data.
 359  *
 360  * Arguments:        tty    pointer to associated tty instance data
 361  * Return Value:    None
 362  */
 363 static void hci_uart_tty_wakeup(struct tty_struct *tty)
 364 {
 365         struct hci_uart *hu = (void *)tty->disc_data;
 366
 367         BT_DBG("");
 368
 369         if (!hu)
 370                 return;
 371
 372         clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
 373
 374         if (tty != hu->tty)
 375                 return;
 376
 377         if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
 378                 hci_uart_tx_wakeup(hu);
 379 }
 380
 381 /* hci_uart_tty_receive()
 382  *
 383  *     Called by tty low level driver when receive data is
 384  *     available.
 385  *
 386  * Arguments:  tty          pointer to tty isntance data
 387  *             data         pointer to received data
 388  *             flags        pointer to flags for data
 389  *             count        count of received data in bytes
 390  *
 391  * Return Value:    None
 392  */
 393 static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data, char *flags, int count)
 394 {
 395         struct hci_uart *hu = (void *)tty->disc_data;
 396
 397         if (!hu || tty != hu->tty)
 398                 return;
 399
 400         if (!test_bit(HCI_UART_PROTO_SET, &hu->flags))
 401                 return;
 402
 403         spin_lock(&hu->rx_lock);
 404         hu->proto->recv(hu, (void *) data, count);
 405
 406         if (hu->hdev)
 407                 hu->hdev->stat.byte_rx += count;
 408
 409         spin_unlock(&hu->rx_lock);
 410
 411         tty_unthrottle(tty);
 412 }
 413
 414 static int hci_uart_register_dev(struct hci_uart *hu)
 415 {
 416         struct hci_dev *hdev;
 417
 418         BT_DBG("");
 419
 420         /* Initialize and register HCI device */
 421         hdev = hci_alloc_dev();
 422         if (!hdev) {
 423                 BT_ERR("Can't allocate HCI device");
 424                 return -ENOMEM;
 425         }
 426
 427         hu->hdev = hdev;
 428
 429         hdev->bus = HCI_UART;
 430         hci_set_drvdata(hdev, hu);
 431
 432         hdev->open  = hci_uart_open;
 433         hdev->close = hci_uart_close;
 434         hdev->flush = hci_uart_flush;
 435         hdev->send  = hci_uart_send_frame;
 436         SET_HCIDEV_DEV(hdev, hu->tty->dev);
 437
 438         if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags))
 439                 set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
 440
 441         if (!test_bit(HCI_UART_RESET_ON_INIT, &hu->hdev_flags))
 442                 set_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks);
 443
 444         if (test_bit(HCI_UART_CREATE_AMP, &hu->hdev_flags))
 445                 hdev->dev_type = HCI_AMP;
 446         else
 447                 hdev->dev_type = HCI_BREDR;
 448
 449         if (test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
 450                 return 0;
 451
 452         if (hci_register_dev(hdev) < 0) {
 453                 BT_ERR("Can't register HCI device");
 454                 hci_free_dev(hdev);
 455                 return -ENODEV;
 456         }
 457
 458         set_bit(HCI_UART_REGISTERED, &hu->flags);
 459
 460         return 0;
 461 }
 462
 463 static int hci_uart_set_proto(struct hci_uart *hu, int id)
 464 {
 465         struct hci_uart_proto *p;
 466         int err;
 467
 468         p = hci_uart_get_proto(id);
 469         if (!p)
 470                 return -EPROTONOSUPPORT;
 471
 472         err = p->open(hu);
 473         if (err)
 474                 return err;
 475
 476         hu->proto = p;
 477
 478         err = hci_uart_register_dev(hu);
 479         if (err) {
 480                 p->close(hu);
 481                 return err;
 482         }
 483
 484         return 0;
 485 }
 486
 487 /* hci_uart_tty_ioctl()
 488  *
 489  *    Process IOCTL system call for the tty device.
 490  *
 491  * Arguments:
 492  *
 493  *    tty        pointer to tty instance data
 494  *    file       pointer to open file object for device
 495  *    cmd        IOCTL command code
 496  *    arg        argument for IOCTL call (cmd dependent)
 497  *
 498  * Return Value:    Command dependent
 499  */
 500 static int hci_uart_tty_ioctl(struct tty_struct *tty, struct file * file,
 501                                         unsigned int cmd, unsigned long arg)
 502 {
 503         struct hci_uart *hu = (void *)tty->disc_data;
 504         int err = 0;
 505
 506         BT_DBG("");
 507
 508         /* Verify the status of the device */
 509         if (!hu)
 510                 return -EBADF;
 511
 512         switch (cmd) {
 513         case HCIUARTSETPROTO:
 514                 if (!test_and_set_bit(HCI_UART_PROTO_SET, &hu->flags)) {
 515                         err = hci_uart_set_proto(hu, arg);
 516                         if (err) {
 517                                 clear_bit(HCI_UART_PROTO_SET, &hu->flags);
 518                                 return err;
 519                         }
 520                 } else
 521                         return -EBUSY;
 522                 break;
 523
 524         case HCIUARTGETPROTO:
 525                 if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
 526                         return hu->proto->id;
 527                 return -EUNATCH;
 528
 529         case HCIUARTGETDEVICE:
 530                 if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
 531                         return hu->hdev->id;
 532                 return -EUNATCH;
 533
 534         case HCIUARTSETFLAGS:
 535                 if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
 536                         return -EBUSY;
 537                 hu->hdev_flags = arg;
 538                 break;
 539
 540         case HCIUARTGETFLAGS:
 541                 return hu->hdev_flags;
 542
 543         default:
 544                 err = n_tty_ioctl_helper(tty, file, cmd, arg);
 545                 break;
 546         }
 547
 548         return err;
 549 }
 550
 551 /*
 552  * We don't provide read/write/poll interface for user space.
 553  */
 554 static ssize_t hci_uart_tty_read(struct tty_struct *tty, struct file *file,
 555                                         unsigned char __user *buf, size_t nr)
 556 {
 557         return 0;
 558 }
 559
 560 static ssize_t hci_uart_tty_write(struct tty_struct *tty, struct file *file,
 561                                         const unsigned char *data, size_t count)
 562 {
 563         return 0;
 564 }
 565
 566 static unsigned int hci_uart_tty_poll(struct tty_struct *tty,
 567                                         struct file *filp, poll_table *wait)
 568 {
 569         return 0;
 570 }
 571
 572 static int __init hci_uart_init(void)
 573 {
 574         static struct tty_ldisc_ops hci_uart_ldisc;
 575         int err;
 576
 577         BT_INFO("HCI UART driver ver %s", VERSION);
 578
 579         /* Register the tty discipline */
 580
 581         memset(&hci_uart_ldisc, 0, sizeof (hci_uart_ldisc));
 582         hci_uart_ldisc.magic            = TTY_LDISC_MAGIC;
 583         hci_uart_ldisc.name             = "n_hci";
 584         hci_uart_ldisc.open             = hci_uart_tty_open;
 585         hci_uart_ldisc.close            = hci_uart_tty_close;
 586         hci_uart_ldisc.read             = hci_uart_tty_read;
 587         hci_uart_ldisc.write            = hci_uart_tty_write;
 588         hci_uart_ldisc.ioctl            = hci_uart_tty_ioctl;
 589         hci_uart_ldisc.poll             = hci_uart_tty_poll;
 590         hci_uart_ldisc.receive_buf      = hci_uart_tty_receive;
 591         hci_uart_ldisc.write_wakeup     = hci_uart_tty_wakeup;
 592         hci_uart_ldisc.owner            = THIS_MODULE;
 593
 594         if ((err = tty_register_ldisc(N_HCI, &hci_uart_ldisc))) {
 595                 BT_ERR("HCI line discipline registration failed. (%d)", err);
 596                 return err;
 597         }
 598
 599 #ifdef CONFIG_BT_HCIUART_H4
 600         h4_init();
 601 #endif
 602 #ifdef CONFIG_BT_HCIUART_BCSP
 603         bcsp_init();
 604 #endif
 605 #ifdef CONFIG_BT_HCIUART_LL
 606         ll_init();
 607 #endif
 608 #ifdef CONFIG_BT_HCIUART_ATH3K
 609         ath_init();
 610 #endif
 611 #ifdef CONFIG_BT_HCIUART_3WIRE
 612         h5_init();
 613 #endif
 614
 615         return 0;
 616 }
 617
 618 static void __exit hci_uart_exit(void)
 619 {
 620         int err;
 621
 622 #ifdef CONFIG_BT_HCIUART_H4
 623         h4_deinit();
 624 #endif
 625 #ifdef CONFIG_BT_HCIUART_BCSP
 626         bcsp_deinit();
 627 #endif
 628 #ifdef CONFIG_BT_HCIUART_LL
 629         ll_deinit();
 630 #endif
 631 #ifdef CONFIG_BT_HCIUART_ATH3K
 632         ath_deinit();
 633 #endif
 634 #ifdef CONFIG_BT_HCIUART_3WIRE
 635         h5_deinit();
 636 #endif
 637
 638         /* Release tty registration of line discipline */
 639         if ((err = tty_unregister_ldisc(N_HCI)))
 640                 BT_ERR("Can't unregister HCI line discipline (%d)", err);
 641 }
 642
 643 module_init(hci_uart_init);
 644 module_exit(hci_uart_exit);
 645
 646 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
 647 MODULE_DESCRIPTION("Bluetooth HCI UART driver ver " VERSION);
 648 MODULE_VERSION(VERSION);
 649 MODULE_LICENSE("GPL");
 650 MODULE_ALIAS_LDISC(N_HCI);