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