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); 629