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         struct tty_struct *tty = hu->tty;
 122         struct hci_dev *hdev = hu->hdev;
 123         struct sk_buff *skb;
 124
 125         if (test_and_set_bit(HCI_UART_SENDING, &hu->tx_state)) {
 126                 set_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
 127                 return 0;
 128         }
 129
 130         BT_DBG("");
 131
 132 restart:
 133         clear_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
 134
 135         while ((skb = hci_uart_dequeue(hu))) {
 136                 int len;
 137
 138                 set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
 139                 len = tty->ops->write(tty, skb->data, skb->len);
 140                 hdev->stat.byte_tx += len;
 141
 142                 skb_pull(skb, len);
 143                 if (skb->len) {
 144                         hu->tx_skb = skb;
 145                         break;
 146                 }
 147
 148                 hci_uart_tx_complete(hu, bt_cb(skb)->pkt_type);
 149                 kfree_skb(skb);
 150         }
 151
 152         if (test_bit(HCI_UART_TX_WAKEUP, &hu->tx_state))
 153                 goto restart;
 154
 155         clear_bit(HCI_UART_SENDING, &hu->tx_state);
 156         return 0;
 157 }
 158
 159 static void hci_uart_init_work(struct work_struct *work)
 160 {
 161         struct hci_uart *hu = container_of(work, struct hci_uart, init_ready);
 162         int err;
 163
 164         if (!test_and_clear_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
 165                 return;
 166
 167         err = hci_register_dev(hu->hdev);
 168         if (err < 0) {
 169                 BT_ERR("Can't register HCI device");
 170                 hci_free_dev(hu->hdev);
 171                 hu->hdev = NULL;
 172                 hu->proto->close(hu);
 173         }
 174
 175         set_bit(HCI_UART_REGISTERED, &hu->flags);
 176 }
 177
 178 int hci_uart_init_ready(struct hci_uart *hu)
 179 {
 180         if (!test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
 181                 return -EALREADY;
 182
 183         schedule_work(&hu->init_ready);
 184
 185         return 0;
 186 }
 187
 188 /* ------- Interface to HCI layer ------ */
 189 /* Initialize device */
 190 static int hci_uart_open(struct hci_dev *hdev)
 191 {
 192         BT_DBG("%s %p", hdev->name, hdev);
 193
 194         /* Nothing to do for UART driver */
 195
 196         set_bit(HCI_RUNNING, &hdev->flags);
 197
 198         return 0;
 199 }
 200
 201 /* Reset device */
 202 static int hci_uart_flush(struct hci_dev *hdev)
 203 {
 204         struct hci_uart *hu  = hci_get_drvdata(hdev);
 205         struct tty_struct *tty = hu->tty;
 206
 207         BT_DBG("hdev %p tty %p", hdev, tty);
 208
 209         if (hu->tx_skb) {
 210                 kfree_skb(hu->tx_skb); hu->tx_skb = NULL;
 211         }
 212
 213         /* Flush any pending characters in the driver and discipline. */
 214         tty_ldisc_flush(tty);
 215         tty_driver_flush_buffer(tty);
 216
 217         if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
 218                 hu->proto->flush(hu);
 219
 220         return 0;
 221 }
 222
 223 /* Close device */
 224 static int hci_uart_close(struct hci_dev *hdev)
 225 {
 226         BT_DBG("hdev %p", hdev);
 227
 228         if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags))
 229                 return 0;
 230
 231         hci_uart_flush(hdev);
 232         hdev->flush = NULL;
 233         return 0;
 234 }
 235
 236 /* Send frames from HCI layer */
 237 static int hci_uart_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
 238 {
 239         struct hci_uart *hu = hci_get_drvdata(hdev);
 240
 241         if (!test_bit(HCI_RUNNING, &hdev->flags))
 242                 return -EBUSY;
 243
 244         BT_DBG("%s: type %d len %d", hdev->name, bt_cb(skb)->pkt_type, skb->len);
 245
 246         hu->proto->enqueue(hu, skb);
 247
 248         hci_uart_tx_wakeup(hu);
 249
 250         return 0;
 251 }
 252
 253 /* ------ LDISC part ------ */
 254 /* hci_uart_tty_open
 255  *
 256  *     Called when line discipline changed to HCI_UART.
 257  *
 258  * Arguments:
 259  *     tty    pointer to tty info structure
 260  * Return Value:
 261  *     0 if success, otherwise error code
 262  */
 263 static int hci_uart_tty_open(struct tty_struct *tty)
 264 {
 265         struct hci_uart *hu;
 266
 267         BT_DBG("tty %p", tty);
 268
 269         /* Error if the tty has no write op instead of leaving an exploitable
 270            hole */
 271         if (tty->ops->write == NULL)
 272                 return -EOPNOTSUPP;
 273
 274         hu = kzalloc(sizeof(struct hci_uart), GFP_KERNEL);
 275         if (!hu) {
 276                 BT_ERR("Can't allocate control structure");
 277                 return -ENFILE;
 278         }
 279
 280         tty->disc_data = hu;
 281         hu->tty = tty;
 282         tty->receive_room = 65536;
 283
 284         INIT_WORK(&hu->init_ready, hci_uart_init_work);
 285
 286         spin_lock_init(&hu->rx_lock);
 287
 288         /* Flush any pending characters in the driver and line discipline. */
 289
 290         /* FIXME: why is this needed. Note don't use ldisc_ref here as the
 291            open path is before the ldisc is referencable */
 292
 293         if (tty->ldisc->ops->flush_buffer)
 294                 tty->ldisc->ops->flush_buffer(tty);
 295         tty_driver_flush_buffer(tty);
 296
 297         return 0;
 298 }
 299
 300 /* hci_uart_tty_close()
 301  *
 302  *    Called when the line discipline is changed to something
 303  *    else, the tty is closed, or the tty detects a hangup.
 304  */
 305 static void hci_uart_tty_close(struct tty_struct *tty)
 306 {
 307         struct hci_uart *hu = (void *)tty->disc_data;
 308         struct hci_dev *hdev;
 309
 310         BT_DBG("tty %p", tty);
 311
 312         /* Detach from the tty */
 313         tty->disc_data = NULL;
 314
 315         if (!hu)
 316                 return;
 317
 318         hdev = hu->hdev;
 319         if (hdev)
 320                 hci_uart_close(hdev);
 321
 322         if (test_and_clear_bit(HCI_UART_PROTO_SET, &hu->flags)) {
 323                 if (hdev) {
 324                         if (test_bit(HCI_UART_REGISTERED, &hu->flags))
 325                                 hci_unregister_dev(hdev);
 326                         hci_free_dev(hdev);
 327                 }
 328                 hu->proto->close(hu);
 329         }
 330
 331         kfree(hu);
 332 }
 333
 334 /* hci_uart_tty_wakeup()
 335  *
 336  *    Callback for transmit wakeup. Called when low level
 337  *    device driver can accept more send data.
 338  *
 339  * Arguments:        tty    pointer to associated tty instance data
 340  * Return Value:    None
 341  */
 342 static void hci_uart_tty_wakeup(struct tty_struct *tty)
 343 {
 344         struct hci_uart *hu = (void *)tty->disc_data;
 345
 346         BT_DBG("");
 347
 348         if (!hu)
 349                 return;
 350
 351         clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
 352
 353         if (tty != hu->tty)
 354                 return;
 355
 356         if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
 357                 hci_uart_tx_wakeup(hu);
 358 }
 359
 360 /* hci_uart_tty_receive()
 361  *
 362  *     Called by tty low level driver when receive data is
 363  *     available.
 364  *
 365  * Arguments:  tty          pointer to tty isntance data
 366  *             data         pointer to received data
 367  *             flags        pointer to flags for data
 368  *             count        count of received data in bytes
 369  *
 370  * Return Value:    None
 371  */
 372 static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data, char *flags, int count)
 373 {
 374         struct hci_uart *hu = (void *)tty->disc_data;
 375
 376         if (!hu || tty != hu->tty)
 377                 return;
 378
 379         if (!test_bit(HCI_UART_PROTO_SET, &hu->flags))
 380                 return;
 381
 382         spin_lock(&hu->rx_lock);
 383         hu->proto->recv(hu, (void *) data, count);
 384
 385         if (hu->hdev)
 386                 hu->hdev->stat.byte_rx += count;
 387
 388         spin_unlock(&hu->rx_lock);
 389
 390         tty_unthrottle(tty);
 391 }
 392
 393 static int hci_uart_register_dev(struct hci_uart *hu)
 394 {
 395         struct hci_dev *hdev;
 396
 397         BT_DBG("");
 398
 399         /* Initialize and register HCI device */
 400         hdev = hci_alloc_dev();
 401         if (!hdev) {
 402                 BT_ERR("Can't allocate HCI device");
 403                 return -ENOMEM;
 404         }
 405
 406         hu->hdev = hdev;
 407
 408         hdev->bus = HCI_UART;
 409         hci_set_drvdata(hdev, hu);
 410
 411         hdev->open  = hci_uart_open;
 412         hdev->close = hci_uart_close;
 413         hdev->flush = hci_uart_flush;
 414         hdev->send  = hci_uart_send_frame;
 415         SET_HCIDEV_DEV(hdev, hu->tty->dev);
 416
 417         if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags))
 418                 set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
 419
 420         if (!test_bit(HCI_UART_RESET_ON_INIT, &hu->hdev_flags))
 421                 set_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks);
 422
 423         if (test_bit(HCI_UART_CREATE_AMP, &hu->hdev_flags))
 424                 hdev->dev_type = HCI_AMP;
 425         else
 426                 hdev->dev_type = HCI_BREDR;
 427
 428         if (test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
 429                 return 0;
 430
 431         if (hci_register_dev(hdev) < 0) {
 432                 BT_ERR("Can't register HCI device");
 433                 hci_free_dev(hdev);
 434                 return -ENODEV;
 435         }
 436
 437         set_bit(HCI_UART_REGISTERED, &hu->flags);
 438
 439         return 0;
 440 }
 441
 442 static int hci_uart_set_proto(struct hci_uart *hu, int id)
 443 {
 444         struct hci_uart_proto *p;
 445         int err;
 446
 447         p = hci_uart_get_proto(id);
 448         if (!p)
 449                 return -EPROTONOSUPPORT;
 450
 451         err = p->open(hu);
 452         if (err)
 453                 return err;
 454
 455         hu->proto = p;
 456
 457         err = hci_uart_register_dev(hu);
 458         if (err) {
 459                 p->close(hu);
 460                 return err;
 461         }
 462
 463         return 0;
 464 }
 465
 466 /* hci_uart_tty_ioctl()
 467  *
 468  *    Process IOCTL system call for the tty device.
 469  *
 470  * Arguments:
 471  *
 472  *    tty        pointer to tty instance data
 473  *    file       pointer to open file object for device
 474  *    cmd        IOCTL command code
 475  *    arg        argument for IOCTL call (cmd dependent)
 476  *
 477  * Return Value:    Command dependent
 478  */
 479 static int hci_uart_tty_ioctl(struct tty_struct *tty, struct file * file,
 480                                         unsigned int cmd, unsigned long arg)
 481 {
 482         struct hci_uart *hu = (void *)tty->disc_data;
 483         int err = 0;
 484
 485         BT_DBG("");
 486
 487         /* Verify the status of the device */
 488         if (!hu)
 489                 return -EBADF;
 490
 491         switch (cmd) {
 492         case HCIUARTSETPROTO:
 493                 if (!test_and_set_bit(HCI_UART_PROTO_SET, &hu->flags)) {
 494                         err = hci_uart_set_proto(hu, arg);
 495                         if (err) {
 496                                 clear_bit(HCI_UART_PROTO_SET, &hu->flags);
 497                                 return err;
 498                         }
 499                 } else
 500                         return -EBUSY;
 501                 break;
 502
 503         case HCIUARTGETPROTO:
 504                 if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
 505                         return hu->proto->id;
 506                 return -EUNATCH;
 507
 508         case HCIUARTGETDEVICE:
 509                 if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
 510                         return hu->hdev->id;
 511                 return -EUNATCH;
 512
 513         case HCIUARTSETFLAGS:
 514                 if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
 515                         return -EBUSY;
 516                 hu->hdev_flags = arg;
 517                 break;
 518
 519         case HCIUARTGETFLAGS:
 520                 return hu->hdev_flags;
 521
 522         default:
 523                 err = n_tty_ioctl_helper(tty, file, cmd, arg);
 524                 break;
 525         }
 526
 527         return err;
 528 }
 529
 530 /*
 531  * We don't provide read/write/poll interface for user space.
 532  */
 533 static ssize_t hci_uart_tty_read(struct tty_struct *tty, struct file *file,
 534                                         unsigned char __user *buf, size_t nr)
 535 {
 536         return 0;
 537 }
 538
 539 static ssize_t hci_uart_tty_write(struct tty_struct *tty, struct file *file,
 540                                         const unsigned char *data, size_t count)
 541 {
 542         return 0;
 543 }
 544
 545 static unsigned int hci_uart_tty_poll(struct tty_struct *tty,
 546                                         struct file *filp, poll_table *wait)
 547 {
 548         return 0;
 549 }
 550
 551 static int __init hci_uart_init(void)
 552 {
 553         static struct tty_ldisc_ops hci_uart_ldisc;
 554         int err;
 555
 556         BT_INFO("HCI UART driver ver %s", VERSION);
 557
 558         /* Register the tty discipline */
 559
 560         memset(&hci_uart_ldisc, 0, sizeof (hci_uart_ldisc));
 561         hci_uart_ldisc.magic            = TTY_LDISC_MAGIC;
 562         hci_uart_ldisc.name             = "n_hci";
 563         hci_uart_ldisc.open             = hci_uart_tty_open;
 564         hci_uart_ldisc.close            = hci_uart_tty_close;
 565         hci_uart_ldisc.read             = hci_uart_tty_read;
 566         hci_uart_ldisc.write            = hci_uart_tty_write;
 567         hci_uart_ldisc.ioctl            = hci_uart_tty_ioctl;
 568         hci_uart_ldisc.poll             = hci_uart_tty_poll;
 569         hci_uart_ldisc.receive_buf      = hci_uart_tty_receive;
 570         hci_uart_ldisc.write_wakeup     = hci_uart_tty_wakeup;
 571         hci_uart_ldisc.owner            = THIS_MODULE;
 572
 573         err = tty_register_ldisc(N_HCI, &hci_uart_ldisc);
 574         if (err) {
 575                 BT_ERR("HCI line discipline registration failed. (%d)", err);
 576                 return err;
 577         }
 578
 579 #ifdef CONFIG_BT_HCIUART_H4
 580         h4_init();
 581 #endif
 582 #ifdef CONFIG_BT_HCIUART_BCSP
 583         bcsp_init();
 584 #endif
 585 #ifdef CONFIG_BT_HCIUART_LL
 586         ll_init();
 587 #endif
 588 #ifdef CONFIG_BT_HCIUART_ATH3K
 589         ath_init();
 590 #endif
 591 #ifdef CONFIG_BT_HCIUART_3WIRE
 592         h5_init();
 593 #endif
 594
 595         return 0;
 596 }
 597
 598 static void __exit hci_uart_exit(void)
 599 {
 600         int err;
 601
 602 #ifdef CONFIG_BT_HCIUART_H4
 603         h4_deinit();
 604 #endif
 605 #ifdef CONFIG_BT_HCIUART_BCSP
 606         bcsp_deinit();
 607 #endif
 608 #ifdef CONFIG_BT_HCIUART_LL
 609         ll_deinit();
 610 #endif
 611 #ifdef CONFIG_BT_HCIUART_ATH3K
 612         ath_deinit();
 613 #endif
 614 #ifdef CONFIG_BT_HCIUART_3WIRE
 615         h5_deinit();
 616 #endif
 617
 618         /* Release tty registration of line discipline */
 619         err = tty_unregister_ldisc(N_HCI);
 620         if (err)
 621                 BT_ERR("Can't unregister HCI line discipline (%d)", err);
 622 }
 623
 624 module_init(hci_uart_init);
 625 module_exit(hci_uart_exit);
 626
 627 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
 628 MODULE_DESCRIPTION("Bluetooth HCI UART driver ver " VERSION);
 629 MODULE_VERSION(VERSION);
 630 MODULE_LICENSE("GPL");
 631 MODULE_ALIAS_LDISC(N_HCI);