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