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 sk_buff *skb) 238 { 239 struct hci_dev* hdev = (struct hci_dev *) skb->dev; 240 struct hci_uart *hu; 241 242 if (!hdev) { 243 BT_ERR("Frame for unknown device (hdev=NULL)"); 244 return -ENODEV; 245 } 246 247 if (!test_bit(HCI_RUNNING, &hdev->flags)) 248 return -EBUSY; 249 250 hu = hci_get_drvdata(hdev); 251 252 BT_DBG("%s: type %d len %d", hdev->name, bt_cb(skb)->pkt_type, skb->len); 253 254 hu->proto->enqueue(hu, skb); 255 256 hci_uart_tx_wakeup(hu); 257 258 return 0; 259 } 260 261 /* ------ LDISC part ------ */ 262 /* hci_uart_tty_open 263 * 264 * Called when line discipline changed to HCI_UART. 265 * 266 * Arguments: 267 * tty pointer to tty info structure 268 * Return Value: 269 * 0 if success, otherwise error code 270 */ 271 static int hci_uart_tty_open(struct tty_struct *tty) 272 { 273 struct hci_uart *hu = (void *) tty->disc_data; 274 275 BT_DBG("tty %p", tty); 276 277 /* FIXME: This btw is bogus, nothing requires the old ldisc to clear 278 the pointer */ 279 if (hu) 280 return -EEXIST; 281 282 /* Error if the tty has no write op instead of leaving an exploitable 283 hole */ 284 if (tty->ops->write == NULL) 285 return -EOPNOTSUPP; 286 287 if (!(hu = kzalloc(sizeof(struct hci_uart), GFP_KERNEL))) { 288 BT_ERR("Can't allocate control structure"); 289 return -ENFILE; 290 } 291 292 tty->disc_data = hu; 293 hu->tty = tty; 294 tty->receive_room = 65536; 295 296 INIT_WORK(&hu->init_ready, hci_uart_init_work); 297 298 spin_lock_init(&hu->rx_lock); 299 300 /* Flush any pending characters in the driver and line discipline. */ 301 302 /* FIXME: why is this needed. Note don't use ldisc_ref here as the 303 open path is before the ldisc is referencable */ 304 305 if (tty->ldisc->ops->flush_buffer) 306 tty->ldisc->ops->flush_buffer(tty); 307 tty_driver_flush_buffer(tty); 308 309 return 0; 310 } 311 312 /* hci_uart_tty_close() 313 * 314 * Called when the line discipline is changed to something 315 * else, the tty is closed, or the tty detects a hangup. 316 */ 317 static void hci_uart_tty_close(struct tty_struct *tty) 318 { 319 struct hci_uart *hu = (void *)tty->disc_data; 320 struct hci_dev *hdev; 321 322 BT_DBG("tty %p", tty); 323 324 /* Detach from the tty */ 325 tty->disc_data = NULL; 326 327 if (!hu) 328 return; 329 330 hdev = hu->hdev; 331 if (hdev) 332 hci_uart_close(hdev); 333 334 if (test_and_clear_bit(HCI_UART_PROTO_SET, &hu->flags)) { 335 if (hdev) { 336 if (test_bit(HCI_UART_REGISTERED, &hu->flags)) 337 hci_unregister_dev(hdev); 338 hci_free_dev(hdev); 339 } 340 hu->proto->close(hu); 341 } 342 343 kfree(hu); 344 } 345 346 /* hci_uart_tty_wakeup() 347 * 348 * Callback for transmit wakeup. Called when low level 349 * device driver can accept more send data. 350 * 351 * Arguments: tty pointer to associated tty instance data 352 * Return Value: None 353 */ 354 static void hci_uart_tty_wakeup(struct tty_struct *tty) 355 { 356 struct hci_uart *hu = (void *)tty->disc_data; 357 358 BT_DBG(""); 359 360 if (!hu) 361 return; 362 363 clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); 364 365 if (tty != hu->tty) 366 return; 367 368 if (test_bit(HCI_UART_PROTO_SET, &hu->flags)) 369 hci_uart_tx_wakeup(hu); 370 } 371 372 /* hci_uart_tty_receive() 373 * 374 * Called by tty low level driver when receive data is 375 * available. 376 * 377 * Arguments: tty pointer to tty isntance data 378 * data pointer to received data 379 * flags pointer to flags for data 380 * count count of received data in bytes 381 * 382 * Return Value: None 383 */ 384 static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data, char *flags, int count) 385 { 386 struct hci_uart *hu = (void *)tty->disc_data; 387 388 if (!hu || tty != hu->tty) 389 return; 390 391 if (!test_bit(HCI_UART_PROTO_SET, &hu->flags)) 392 return; 393 394 spin_lock(&hu->rx_lock); 395 hu->proto->recv(hu, (void *) data, count); 396 hu->hdev->stat.byte_rx += count; 397 spin_unlock(&hu->rx_lock); 398 399 tty_unthrottle(tty); 400 } 401 402 static int hci_uart_register_dev(struct hci_uart *hu) 403 { 404 struct hci_dev *hdev; 405 406 BT_DBG(""); 407 408 /* Initialize and register HCI device */ 409 hdev = hci_alloc_dev(); 410 if (!hdev) { 411 BT_ERR("Can't allocate HCI device"); 412 return -ENOMEM; 413 } 414 415 hu->hdev = hdev; 416 417 hdev->bus = HCI_UART; 418 hci_set_drvdata(hdev, hu); 419 420 hdev->open = hci_uart_open; 421 hdev->close = hci_uart_close; 422 hdev->flush = hci_uart_flush; 423 hdev->send = hci_uart_send_frame; 424 SET_HCIDEV_DEV(hdev, hu->tty->dev); 425 426 if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags)) 427 set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks); 428 429 if (!test_bit(HCI_UART_RESET_ON_INIT, &hu->hdev_flags)) 430 set_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks); 431 432 if (test_bit(HCI_UART_CREATE_AMP, &hu->hdev_flags)) 433 hdev->dev_type = HCI_AMP; 434 else 435 hdev->dev_type = HCI_BREDR; 436 437 if (test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags)) 438 return 0; 439 440 if (hci_register_dev(hdev) < 0) { 441 BT_ERR("Can't register HCI device"); 442 hci_free_dev(hdev); 443 return -ENODEV; 444 } 445 446 set_bit(HCI_UART_REGISTERED, &hu->flags); 447 448 return 0; 449 } 450 451 static int hci_uart_set_proto(struct hci_uart *hu, int id) 452 { 453 struct hci_uart_proto *p; 454 int err; 455 456 p = hci_uart_get_proto(id); 457 if (!p) 458 return -EPROTONOSUPPORT; 459 460 err = p->open(hu); 461 if (err) 462 return err; 463 464 hu->proto = p; 465 466 err = hci_uart_register_dev(hu); 467 if (err) { 468 p->close(hu); 469 return err; 470 } 471 472 return 0; 473 } 474 475 /* hci_uart_tty_ioctl() 476 * 477 * Process IOCTL system call for the tty device. 478 * 479 * Arguments: 480 * 481 * tty pointer to tty instance data 482 * file pointer to open file object for device 483 * cmd IOCTL command code 484 * arg argument for IOCTL call (cmd dependent) 485 * 486 * Return Value: Command dependent 487 */ 488 static int hci_uart_tty_ioctl(struct tty_struct *tty, struct file * file, 489 unsigned int cmd, unsigned long arg) 490 { 491 struct hci_uart *hu = (void *)tty->disc_data; 492 int err = 0; 493 494 BT_DBG(""); 495 496 /* Verify the status of the device */ 497 if (!hu) 498 return -EBADF; 499 500 switch (cmd) { 501 case HCIUARTSETPROTO: 502 if (!test_and_set_bit(HCI_UART_PROTO_SET, &hu->flags)) { 503 err = hci_uart_set_proto(hu, arg); 504 if (err) { 505 clear_bit(HCI_UART_PROTO_SET, &hu->flags); 506 return err; 507 } 508 } else 509 return -EBUSY; 510 break; 511 512 case HCIUARTGETPROTO: 513 if (test_bit(HCI_UART_PROTO_SET, &hu->flags)) 514 return hu->proto->id; 515 return -EUNATCH; 516 517 case HCIUARTGETDEVICE: 518 if (test_bit(HCI_UART_PROTO_SET, &hu->flags)) 519 return hu->hdev->id; 520 return -EUNATCH; 521 522 case HCIUARTSETFLAGS: 523 if (test_bit(HCI_UART_PROTO_SET, &hu->flags)) 524 return -EBUSY; 525 hu->hdev_flags = arg; 526 break; 527 528 case HCIUARTGETFLAGS: 529 return hu->hdev_flags; 530 531 default: 532 err = n_tty_ioctl_helper(tty, file, cmd, arg); 533 break; 534 } 535 536 return err; 537 } 538 539 /* 540 * We don't provide read/write/poll interface for user space. 541 */ 542 static ssize_t hci_uart_tty_read(struct tty_struct *tty, struct file *file, 543 unsigned char __user *buf, size_t nr) 544 { 545 return 0; 546 } 547 548 static ssize_t hci_uart_tty_write(struct tty_struct *tty, struct file *file, 549 const unsigned char *data, size_t count) 550 { 551 return 0; 552 } 553 554 static unsigned int hci_uart_tty_poll(struct tty_struct *tty, 555 struct file *filp, poll_table *wait) 556 { 557 return 0; 558 } 559 560 static int __init hci_uart_init(void) 561 { 562 static struct tty_ldisc_ops hci_uart_ldisc; 563 int err; 564 565 BT_INFO("HCI UART driver ver %s", VERSION); 566 567 /* Register the tty discipline */ 568 569 memset(&hci_uart_ldisc, 0, sizeof (hci_uart_ldisc)); 570 hci_uart_ldisc.magic = TTY_LDISC_MAGIC; 571 hci_uart_ldisc.name = "n_hci"; 572 hci_uart_ldisc.open = hci_uart_tty_open; 573 hci_uart_ldisc.close = hci_uart_tty_close; 574 hci_uart_ldisc.read = hci_uart_tty_read; 575 hci_uart_ldisc.write = hci_uart_tty_write; 576 hci_uart_ldisc.ioctl = hci_uart_tty_ioctl; 577 hci_uart_ldisc.poll = hci_uart_tty_poll; 578 hci_uart_ldisc.receive_buf = hci_uart_tty_receive; 579 hci_uart_ldisc.write_wakeup = hci_uart_tty_wakeup; 580 hci_uart_ldisc.owner = THIS_MODULE; 581 582 if ((err = tty_register_ldisc(N_HCI, &hci_uart_ldisc))) { 583 BT_ERR("HCI line discipline registration failed. (%d)", err); 584 return err; 585 } 586 587 #ifdef CONFIG_BT_HCIUART_H4 588 h4_init(); 589 #endif 590 #ifdef CONFIG_BT_HCIUART_BCSP 591 bcsp_init(); 592 #endif 593 #ifdef CONFIG_BT_HCIUART_LL 594 ll_init(); 595 #endif 596 #ifdef CONFIG_BT_HCIUART_ATH3K 597 ath_init(); 598 #endif 599 #ifdef CONFIG_BT_HCIUART_3WIRE 600 h5_init(); 601 #endif 602 603 return 0; 604 } 605 606 static void __exit hci_uart_exit(void) 607 { 608 int err; 609 610 #ifdef CONFIG_BT_HCIUART_H4 611 h4_deinit(); 612 #endif 613 #ifdef CONFIG_BT_HCIUART_BCSP 614 bcsp_deinit(); 615 #endif 616 #ifdef CONFIG_BT_HCIUART_LL 617 ll_deinit(); 618 #endif 619 #ifdef CONFIG_BT_HCIUART_ATH3K 620 ath_deinit(); 621 #endif 622 #ifdef CONFIG_BT_HCIUART_3WIRE 623 h5_deinit(); 624 #endif 625 626 /* Release tty registration of line discipline */ 627 if ((err = tty_unregister_ldisc(N_HCI))) 628 BT_ERR("Can't unregister HCI line discipline (%d)", err); 629 } 630 631 module_init(hci_uart_init); 632 module_exit(hci_uart_exit); 633 634 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>"); 635 MODULE_DESCRIPTION("Bluetooth HCI UART driver ver " VERSION); 636 MODULE_VERSION(VERSION); 637 MODULE_LICENSE("GPL"); 638 MODULE_ALIAS_LDISC(N_HCI); 639