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 int reset = 0;
  52
  53 static struct hci_uart_proto *hup[HCI_UART_MAX_PROTO];
  54
  55 int hci_uart_register_proto(struct hci_uart_proto *p)
  56 {
  57         if (p->id >= HCI_UART_MAX_PROTO)
  58                 return -EINVAL;
  59
  60         if (hup[p->id])
  61                 return -EEXIST;
  62
  63         hup[p->id] = p;
  64
  65         return 0;
  66 }
  67
  68 int hci_uart_unregister_proto(struct hci_uart_proto *p)
  69 {
  70         if (p->id >= HCI_UART_MAX_PROTO)
  71                 return -EINVAL;
  72
  73         if (!hup[p->id])
  74                 return -EINVAL;
  75
  76         hup[p->id] = NULL;
  77
  78         return 0;
  79 }
  80
  81 static struct hci_uart_proto *hci_uart_get_proto(unsigned int id)
  82 {
  83         if (id >= HCI_UART_MAX_PROTO)
  84                 return NULL;
  85
  86         return hup[id];
  87 }
  88
  89 static inline void hci_uart_tx_complete(struct hci_uart *hu, int pkt_type)
  90 {
  91         struct hci_dev *hdev = hu->hdev;
  92
  93         /* Update HCI stat counters */
  94         switch (pkt_type) {
  95         case HCI_COMMAND_PKT:
  96                 hdev->stat.cmd_tx++;
  97                 break;
  98
  99         case HCI_ACLDATA_PKT:
 100                 hdev->stat.acl_tx++;
 101                 break;
 102
 103         case HCI_SCODATA_PKT:
 104                 hdev->stat.sco_tx++;
 105                 break;
 106         }
 107 }
 108
 109 static inline struct sk_buff *hci_uart_dequeue(struct hci_uart *hu)
 110 {
 111         struct sk_buff *skb = hu->tx_skb;
 112
 113         if (!skb)
 114                 skb = hu->proto->dequeue(hu);
 115         else
 116                 hu->tx_skb = NULL;
 117
 118         return skb;
 119 }
 120
 121 int hci_uart_tx_wakeup(struct hci_uart *hu)
 122 {
 123         struct tty_struct *tty = hu->tty;
 124         struct hci_dev *hdev = hu->hdev;
 125         struct sk_buff *skb;
 126
 127         if (test_and_set_bit(HCI_UART_SENDING, &hu->tx_state)) {
 128                 set_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
 129                 return 0;
 130         }
 131
 132         BT_DBG("");
 133
 134 restart:
 135         clear_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
 136
 137         while ((skb = hci_uart_dequeue(hu))) {
 138                 int len;
 139
 140                 set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
 141                 len = tty->ops->write(tty, skb->data, skb->len);
 142                 hdev->stat.byte_tx += len;
 143
 144                 skb_pull(skb, len);
 145                 if (skb->len) {
 146                         hu->tx_skb = skb;
 147                         break;
 148                 }
 149
 150                 hci_uart_tx_complete(hu, bt_cb(skb)->pkt_type);
 151                 kfree_skb(skb);
 152         }
 153
 154         if (test_bit(HCI_UART_TX_WAKEUP, &hu->tx_state))
 155                 goto restart;
 156
 157         clear_bit(HCI_UART_SENDING, &hu->tx_state);
 158         return 0;
 159 }
 160
 161 /* ------- Interface to HCI layer ------ */
 162 /* Initialize device */
 163 static int hci_uart_open(struct hci_dev *hdev)
 164 {
 165         BT_DBG("%s %p", hdev->name, hdev);
 166
 167         /* Nothing to do for UART driver */
 168
 169         set_bit(HCI_RUNNING, &hdev->flags);
 170
 171         return 0;
 172 }
 173
 174 /* Reset device */
 175 static int hci_uart_flush(struct hci_dev *hdev)
 176 {
 177         struct hci_uart *hu  = (struct hci_uart *) hdev->driver_data;
 178         struct tty_struct *tty = hu->tty;
 179
 180         BT_DBG("hdev %p tty %p", hdev, tty);
 181
 182         if (hu->tx_skb) {
 183                 kfree_skb(hu->tx_skb); hu->tx_skb = NULL;
 184         }
 185
 186         /* Flush any pending characters in the driver and discipline. */
 187         tty_ldisc_flush(tty);
 188         tty_driver_flush_buffer(tty);
 189
 190         if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
 191                 hu->proto->flush(hu);
 192
 193         return 0;
 194 }
 195
 196 /* Close device */
 197 static int hci_uart_close(struct hci_dev *hdev)
 198 {
 199         BT_DBG("hdev %p", hdev);
 200
 201         if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags))
 202                 return 0;
 203
 204         hci_uart_flush(hdev);
 205         hdev->flush = NULL;
 206         return 0;
 207 }
 208
 209 /* Send frames from HCI layer */
 210 static int hci_uart_send_frame(struct sk_buff *skb)
 211 {
 212         struct hci_dev* hdev = (struct hci_dev *) skb->dev;
 213         struct hci_uart *hu;
 214
 215         if (!hdev) {
 216                 BT_ERR("Frame for unknown device (hdev=NULL)");
 217                 return -ENODEV;
 218         }
 219
 220         if (!test_bit(HCI_RUNNING, &hdev->flags))
 221                 return -EBUSY;
 222
 223         hu = (struct hci_uart *) hdev->driver_data;
 224
 225         BT_DBG("%s: type %d len %d", hdev->name, bt_cb(skb)->pkt_type, skb->len);
 226
 227         hu->proto->enqueue(hu, skb);
 228
 229         hci_uart_tx_wakeup(hu);
 230
 231         return 0;
 232 }
 233
 234 /* ------ LDISC part ------ */
 235 /* hci_uart_tty_open
 236  *
 237  *     Called when line discipline changed to HCI_UART.
 238  *
 239  * Arguments:
 240  *     tty    pointer to tty info structure
 241  * Return Value:
 242  *     0 if success, otherwise error code
 243  */
 244 static int hci_uart_tty_open(struct tty_struct *tty)
 245 {
 246         struct hci_uart *hu = (void *) tty->disc_data;
 247
 248         BT_DBG("tty %p", tty);
 249
 250         /* FIXME: This btw is bogus, nothing requires the old ldisc to clear
 251            the pointer */
 252         if (hu)
 253                 return -EEXIST;
 254
 255         /* Error if the tty has no write op instead of leaving an exploitable
 256            hole */
 257         if (tty->ops->write == NULL)
 258                 return -EOPNOTSUPP;
 259
 260         if (!(hu = kzalloc(sizeof(struct hci_uart), GFP_KERNEL))) {
 261                 BT_ERR("Can't allocate control structure");
 262                 return -ENFILE;
 263         }
 264
 265         tty->disc_data = hu;
 266         hu->tty = tty;
 267         tty->receive_room = 65536;
 268
 269         spin_lock_init(&hu->rx_lock);
 270
 271         /* Flush any pending characters in the driver and line discipline. */
 272
 273         /* FIXME: why is this needed. Note don't use ldisc_ref here as the
 274            open path is before the ldisc is referencable */
 275
 276         if (tty->ldisc->ops->flush_buffer)
 277                 tty->ldisc->ops->flush_buffer(tty);
 278         tty_driver_flush_buffer(tty);
 279
 280         return 0;
 281 }
 282
 283 /* hci_uart_tty_close()
 284  *
 285  *    Called when the line discipline is changed to something
 286  *    else, the tty is closed, or the tty detects a hangup.
 287  */
 288 static void hci_uart_tty_close(struct tty_struct *tty)
 289 {
 290         struct hci_uart *hu = (void *)tty->disc_data;
 291
 292         BT_DBG("tty %p", tty);
 293
 294         /* Detach from the tty */
 295         tty->disc_data = NULL;
 296
 297         if (hu) {
 298                 struct hci_dev *hdev = hu->hdev;
 299
 300                 if (hdev)
 301                         hci_uart_close(hdev);
 302
 303                 if (test_and_clear_bit(HCI_UART_PROTO_SET, &hu->flags)) {
 304                         hu->proto->close(hu);
 305                         if (hdev) {
 306                                 hci_unregister_dev(hdev);
 307                                 hci_free_dev(hdev);
 308                         }
 309                 }
 310
 311                 kfree(hu);
 312         }
 313 }
 314
 315 /* hci_uart_tty_wakeup()
 316  *
 317  *    Callback for transmit wakeup. Called when low level
 318  *    device driver can accept more send data.
 319  *
 320  * Arguments:        tty    pointer to associated tty instance data
 321  * Return Value:    None
 322  */
 323 static void hci_uart_tty_wakeup(struct tty_struct *tty)
 324 {
 325         struct hci_uart *hu = (void *)tty->disc_data;
 326
 327         BT_DBG("");
 328
 329         if (!hu)
 330                 return;
 331
 332         clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
 333
 334         if (tty != hu->tty)
 335                 return;
 336
 337         if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
 338                 hci_uart_tx_wakeup(hu);
 339 }
 340
 341 /* hci_uart_tty_receive()
 342  *
 343  *     Called by tty low level driver when receive data is
 344  *     available.
 345  *
 346  * Arguments:  tty          pointer to tty isntance data
 347  *             data         pointer to received data
 348  *             flags        pointer to flags for data
 349  *             count        count of received data in bytes
 350  *
 351  * Return Value:    None
 352  */
 353 static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data, char *flags, int count)
 354 {
 355         struct hci_uart *hu = (void *)tty->disc_data;
 356
 357         if (!hu || tty != hu->tty)
 358                 return;
 359
 360         if (!test_bit(HCI_UART_PROTO_SET, &hu->flags))
 361                 return;
 362
 363         spin_lock(&hu->rx_lock);
 364         hu->proto->recv(hu, (void *) data, count);
 365         hu->hdev->stat.byte_rx += count;
 366         spin_unlock(&hu->rx_lock);
 367
 368         tty_unthrottle(tty);
 369 }
 370
 371 static int hci_uart_register_dev(struct hci_uart *hu)
 372 {
 373         struct hci_dev *hdev;
 374
 375         BT_DBG("");
 376
 377         /* Initialize and register HCI device */
 378         hdev = hci_alloc_dev();
 379         if (!hdev) {
 380                 BT_ERR("Can't allocate HCI device");
 381                 return -ENOMEM;
 382         }
 383
 384         hu->hdev = hdev;
 385
 386         hdev->bus = HCI_UART;
 387         hdev->driver_data = hu;
 388
 389         hdev->open  = hci_uart_open;
 390         hdev->close = hci_uart_close;
 391         hdev->flush = hci_uart_flush;
 392         hdev->send  = hci_uart_send_frame;
 393         hdev->parent = hu->tty->dev;
 394
 395         if (!reset)
 396                 set_bit(HCI_QUIRK_NO_RESET, &hdev->quirks);
 397
 398         if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags))
 399                 set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
 400
 401         if (hci_register_dev(hdev) < 0) {
 402                 BT_ERR("Can't register HCI device");
 403                 hci_free_dev(hdev);
 404                 return -ENODEV;
 405         }
 406
 407         return 0;
 408 }
 409
 410 static int hci_uart_set_proto(struct hci_uart *hu, int id)
 411 {
 412         struct hci_uart_proto *p;
 413         int err;
 414
 415         p = hci_uart_get_proto(id);
 416         if (!p)
 417                 return -EPROTONOSUPPORT;
 418
 419         err = p->open(hu);
 420         if (err)
 421                 return err;
 422
 423         hu->proto = p;
 424
 425         err = hci_uart_register_dev(hu);
 426         if (err) {
 427                 p->close(hu);
 428                 return err;
 429         }
 430
 431         return 0;
 432 }
 433
 434 /* hci_uart_tty_ioctl()
 435  *
 436  *    Process IOCTL system call for the tty device.
 437  *
 438  * Arguments:
 439  *
 440  *    tty        pointer to tty instance data
 441  *    file       pointer to open file object for device
 442  *    cmd        IOCTL command code
 443  *    arg        argument for IOCTL call (cmd dependent)
 444  *
 445  * Return Value:    Command dependent
 446  */
 447 static int hci_uart_tty_ioctl(struct tty_struct *tty, struct file * file,
 448                                         unsigned int cmd, unsigned long arg)
 449 {
 450         struct hci_uart *hu = (void *)tty->disc_data;
 451         int err = 0;
 452
 453         BT_DBG("");
 454
 455         /* Verify the status of the device */
 456         if (!hu)
 457                 return -EBADF;
 458
 459         switch (cmd) {
 460         case HCIUARTSETPROTO:
 461                 if (!test_and_set_bit(HCI_UART_PROTO_SET, &hu->flags)) {
 462                         err = hci_uart_set_proto(hu, arg);
 463                         if (err) {
 464                                 clear_bit(HCI_UART_PROTO_SET, &hu->flags);
 465                                 return err;
 466                         }
 467                 } else
 468                         return -EBUSY;
 469                 break;
 470
 471         case HCIUARTGETPROTO:
 472                 if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
 473                         return hu->proto->id;
 474                 return -EUNATCH;
 475
 476         case HCIUARTGETDEVICE:
 477                 if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
 478                         return hu->hdev->id;
 479                 return -EUNATCH;
 480
 481         case HCIUARTSETFLAGS:
 482                 if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
 483                         return -EBUSY;
 484                 hu->hdev_flags = arg;
 485                 break;
 486
 487         case HCIUARTGETFLAGS:
 488                 return hu->hdev_flags;
 489
 490         default:
 491                 err = n_tty_ioctl_helper(tty, file, cmd, arg);
 492                 break;
 493         };
 494
 495         return err;
 496 }
 497
 498 /*
 499  * We don't provide read/write/poll interface for user space.
 500  */
 501 static ssize_t hci_uart_tty_read(struct tty_struct *tty, struct file *file,
 502                                         unsigned char __user *buf, size_t nr)
 503 {
 504         return 0;
 505 }
 506
 507 static ssize_t hci_uart_tty_write(struct tty_struct *tty, struct file *file,
 508                                         const unsigned char *data, size_t count)
 509 {
 510         return 0;
 511 }
 512
 513 static unsigned int hci_uart_tty_poll(struct tty_struct *tty,
 514                                         struct file *filp, poll_table *wait)
 515 {
 516         return 0;
 517 }
 518
 519 static int __init hci_uart_init(void)
 520 {
 521         static struct tty_ldisc_ops hci_uart_ldisc;
 522         int err;
 523
 524         BT_INFO("HCI UART driver ver %s", VERSION);
 525
 526         /* Register the tty discipline */
 527
 528         memset(&hci_uart_ldisc, 0, sizeof (hci_uart_ldisc));
 529         hci_uart_ldisc.magic            = TTY_LDISC_MAGIC;
 530         hci_uart_ldisc.name             = "n_hci";
 531         hci_uart_ldisc.open             = hci_uart_tty_open;
 532         hci_uart_ldisc.close            = hci_uart_tty_close;
 533         hci_uart_ldisc.read             = hci_uart_tty_read;
 534         hci_uart_ldisc.write            = hci_uart_tty_write;
 535         hci_uart_ldisc.ioctl            = hci_uart_tty_ioctl;
 536         hci_uart_ldisc.poll             = hci_uart_tty_poll;
 537         hci_uart_ldisc.receive_buf      = hci_uart_tty_receive;
 538         hci_uart_ldisc.write_wakeup     = hci_uart_tty_wakeup;
 539         hci_uart_ldisc.owner            = THIS_MODULE;
 540
 541         if ((err = tty_register_ldisc(N_HCI, &hci_uart_ldisc))) {
 542                 BT_ERR("HCI line discipline registration failed. (%d)", err);
 543                 return err;
 544         }
 545
 546 #ifdef CONFIG_BT_HCIUART_H4
 547         h4_init();
 548 #endif
 549 #ifdef CONFIG_BT_HCIUART_BCSP
 550         bcsp_init();
 551 #endif
 552 #ifdef CONFIG_BT_HCIUART_LL
 553         ll_init();
 554 #endif
 555 #ifdef CONFIG_BT_HCIUART_ATH3K
 556         ath_init();
 557 #endif
 558
 559         return 0;
 560 }
 561
 562 static void __exit hci_uart_exit(void)
 563 {
 564         int err;
 565
 566 #ifdef CONFIG_BT_HCIUART_H4
 567         h4_deinit();
 568 #endif
 569 #ifdef CONFIG_BT_HCIUART_BCSP
 570         bcsp_deinit();
 571 #endif
 572 #ifdef CONFIG_BT_HCIUART_LL
 573         ll_deinit();
 574 #endif
 575 #ifdef CONFIG_BT_HCIUART_ATH3K
 576         ath_deinit();
 577 #endif
 578
 579         /* Release tty registration of line discipline */
 580         if ((err = tty_unregister_ldisc(N_HCI)))
 581                 BT_ERR("Can't unregister HCI line discipline (%d)", err);
 582 }
 583
 584 module_init(hci_uart_init);
 585 module_exit(hci_uart_exit);
 586
 587 module_param(reset, bool, 0644);
 588 MODULE_PARM_DESC(reset, "Send HCI reset command on initialization");
 589
 590 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
 591 MODULE_DESCRIPTION("Bluetooth HCI UART driver ver " VERSION);
 592 MODULE_VERSION(VERSION);
 593 MODULE_LICENSE("GPL");
 594 MODULE_ALIAS_LDISC(N_HCI);