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.cmd_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 static void hci_uart_destruct(struct hci_dev *hdev) 235 { 236 if (!hdev) 237 return; 238 239 BT_DBG("%s", hdev->name); 240 kfree(hdev->driver_data); 241 } 242 243 /* ------ LDISC part ------ */ 244 /* hci_uart_tty_open 245 * 246 * Called when line discipline changed to HCI_UART. 247 * 248 * Arguments: 249 * tty pointer to tty info structure 250 * Return Value: 251 * 0 if success, otherwise error code 252 */ 253 static int hci_uart_tty_open(struct tty_struct *tty) 254 { 255 struct hci_uart *hu = (void *) tty->disc_data; 256 257 BT_DBG("tty %p", tty); 258 259 /* FIXME: This btw is bogus, nothing requires the old ldisc to clear 260 the pointer */ 261 if (hu) 262 return -EEXIST; 263 264 /* Error if the tty has no write op instead of leaving an exploitable 265 hole */ 266 if (tty->ops->write == NULL) 267 return -EOPNOTSUPP; 268 269 if (!(hu = kzalloc(sizeof(struct hci_uart), GFP_KERNEL))) { 270 BT_ERR("Can't allocate control structure"); 271 return -ENFILE; 272 } 273 274 tty->disc_data = hu; 275 hu->tty = tty; 276 tty->receive_room = 65536; 277 278 spin_lock_init(&hu->rx_lock); 279 280 /* Flush any pending characters in the driver and line discipline. */ 281 282 /* FIXME: why is this needed. Note don't use ldisc_ref here as the 283 open path is before the ldisc is referencable */ 284 285 if (tty->ldisc->ops->flush_buffer) 286 tty->ldisc->ops->flush_buffer(tty); 287 tty_driver_flush_buffer(tty); 288 289 return 0; 290 } 291 292 /* hci_uart_tty_close() 293 * 294 * Called when the line discipline is changed to something 295 * else, the tty is closed, or the tty detects a hangup. 296 */ 297 static void hci_uart_tty_close(struct tty_struct *tty) 298 { 299 struct hci_uart *hu = (void *)tty->disc_data; 300 301 BT_DBG("tty %p", tty); 302 303 /* Detach from the tty */ 304 tty->disc_data = NULL; 305 306 if (hu) { 307 struct hci_dev *hdev = hu->hdev; 308 309 if (hdev) 310 hci_uart_close(hdev); 311 312 if (test_and_clear_bit(HCI_UART_PROTO_SET, &hu->flags)) { 313 hu->proto->close(hu); 314 hci_unregister_dev(hdev); 315 hci_free_dev(hdev); 316 } 317 } 318 } 319 320 /* hci_uart_tty_wakeup() 321 * 322 * Callback for transmit wakeup. Called when low level 323 * device driver can accept more send data. 324 * 325 * Arguments: tty pointer to associated tty instance data 326 * Return Value: None 327 */ 328 static void hci_uart_tty_wakeup(struct tty_struct *tty) 329 { 330 struct hci_uart *hu = (void *)tty->disc_data; 331 332 BT_DBG(""); 333 334 if (!hu) 335 return; 336 337 clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); 338 339 if (tty != hu->tty) 340 return; 341 342 if (test_bit(HCI_UART_PROTO_SET, &hu->flags)) 343 hci_uart_tx_wakeup(hu); 344 } 345 346 /* hci_uart_tty_receive() 347 * 348 * Called by tty low level driver when receive data is 349 * available. 350 * 351 * Arguments: tty pointer to tty isntance data 352 * data pointer to received data 353 * flags pointer to flags for data 354 * count count of received data in bytes 355 * 356 * Return Value: None 357 */ 358 static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data, char *flags, int count) 359 { 360 struct hci_uart *hu = (void *)tty->disc_data; 361 362 if (!hu || tty != hu->tty) 363 return; 364 365 if (!test_bit(HCI_UART_PROTO_SET, &hu->flags)) 366 return; 367 368 spin_lock(&hu->rx_lock); 369 hu->proto->recv(hu, (void *) data, count); 370 hu->hdev->stat.byte_rx += count; 371 spin_unlock(&hu->rx_lock); 372 373 tty_unthrottle(tty); 374 } 375 376 static int hci_uart_register_dev(struct hci_uart *hu) 377 { 378 struct hci_dev *hdev; 379 380 BT_DBG(""); 381 382 /* Initialize and register HCI device */ 383 hdev = hci_alloc_dev(); 384 if (!hdev) { 385 BT_ERR("Can't allocate HCI device"); 386 return -ENOMEM; 387 } 388 389 hu->hdev = hdev; 390 391 hdev->bus = HCI_UART; 392 hdev->driver_data = hu; 393 394 hdev->open = hci_uart_open; 395 hdev->close = hci_uart_close; 396 hdev->flush = hci_uart_flush; 397 hdev->send = hci_uart_send_frame; 398 hdev->destruct = hci_uart_destruct; 399 400 hdev->owner = THIS_MODULE; 401 402 if (!reset) 403 set_bit(HCI_QUIRK_NO_RESET, &hdev->quirks); 404 405 if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags)) 406 set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks); 407 408 if (hci_register_dev(hdev) < 0) { 409 BT_ERR("Can't register HCI device"); 410 hci_free_dev(hdev); 411 return -ENODEV; 412 } 413 414 return 0; 415 } 416 417 static int hci_uart_set_proto(struct hci_uart *hu, int id) 418 { 419 struct hci_uart_proto *p; 420 int err; 421 422 p = hci_uart_get_proto(id); 423 if (!p) 424 return -EPROTONOSUPPORT; 425 426 err = p->open(hu); 427 if (err) 428 return err; 429 430 hu->proto = p; 431 432 err = hci_uart_register_dev(hu); 433 if (err) { 434 p->close(hu); 435 return err; 436 } 437 438 return 0; 439 } 440 441 /* hci_uart_tty_ioctl() 442 * 443 * Process IOCTL system call for the tty device. 444 * 445 * Arguments: 446 * 447 * tty pointer to tty instance data 448 * file pointer to open file object for device 449 * cmd IOCTL command code 450 * arg argument for IOCTL call (cmd dependent) 451 * 452 * Return Value: Command dependent 453 */ 454 static int hci_uart_tty_ioctl(struct tty_struct *tty, struct file * file, 455 unsigned int cmd, unsigned long arg) 456 { 457 struct hci_uart *hu = (void *)tty->disc_data; 458 int err = 0; 459 460 BT_DBG(""); 461 462 /* Verify the status of the device */ 463 if (!hu) 464 return -EBADF; 465 466 switch (cmd) { 467 case HCIUARTSETPROTO: 468 if (!test_and_set_bit(HCI_UART_PROTO_SET, &hu->flags)) { 469 err = hci_uart_set_proto(hu, arg); 470 if (err) { 471 clear_bit(HCI_UART_PROTO_SET, &hu->flags); 472 return err; 473 } 474 } else 475 return -EBUSY; 476 break; 477 478 case HCIUARTGETPROTO: 479 if (test_bit(HCI_UART_PROTO_SET, &hu->flags)) 480 return hu->proto->id; 481 return -EUNATCH; 482 483 case HCIUARTGETDEVICE: 484 if (test_bit(HCI_UART_PROTO_SET, &hu->flags)) 485 return hu->hdev->id; 486 return -EUNATCH; 487 488 case HCIUARTSETFLAGS: 489 if (test_bit(HCI_UART_PROTO_SET, &hu->flags)) 490 return -EBUSY; 491 hu->hdev_flags = arg; 492 break; 493 494 case HCIUARTGETFLAGS: 495 return hu->hdev_flags; 496 497 default: 498 err = n_tty_ioctl_helper(tty, file, cmd, arg); 499 break; 500 }; 501 502 return err; 503 } 504 505 /* 506 * We don't provide read/write/poll interface for user space. 507 */ 508 static ssize_t hci_uart_tty_read(struct tty_struct *tty, struct file *file, 509 unsigned char __user *buf, size_t nr) 510 { 511 return 0; 512 } 513 514 static ssize_t hci_uart_tty_write(struct tty_struct *tty, struct file *file, 515 const unsigned char *data, size_t count) 516 { 517 return 0; 518 } 519 520 static unsigned int hci_uart_tty_poll(struct tty_struct *tty, 521 struct file *filp, poll_table *wait) 522 { 523 return 0; 524 } 525 526 static int __init hci_uart_init(void) 527 { 528 static struct tty_ldisc_ops hci_uart_ldisc; 529 int err; 530 531 BT_INFO("HCI UART driver ver %s", VERSION); 532 533 /* Register the tty discipline */ 534 535 memset(&hci_uart_ldisc, 0, sizeof (hci_uart_ldisc)); 536 hci_uart_ldisc.magic = TTY_LDISC_MAGIC; 537 hci_uart_ldisc.name = "n_hci"; 538 hci_uart_ldisc.open = hci_uart_tty_open; 539 hci_uart_ldisc.close = hci_uart_tty_close; 540 hci_uart_ldisc.read = hci_uart_tty_read; 541 hci_uart_ldisc.write = hci_uart_tty_write; 542 hci_uart_ldisc.ioctl = hci_uart_tty_ioctl; 543 hci_uart_ldisc.poll = hci_uart_tty_poll; 544 hci_uart_ldisc.receive_buf = hci_uart_tty_receive; 545 hci_uart_ldisc.write_wakeup = hci_uart_tty_wakeup; 546 hci_uart_ldisc.owner = THIS_MODULE; 547 548 if ((err = tty_register_ldisc(N_HCI, &hci_uart_ldisc))) { 549 BT_ERR("HCI line discipline registration failed. (%d)", err); 550 return err; 551 } 552 553 #ifdef CONFIG_BT_HCIUART_H4 554 h4_init(); 555 #endif 556 #ifdef CONFIG_BT_HCIUART_BCSP 557 bcsp_init(); 558 #endif 559 #ifdef CONFIG_BT_HCIUART_LL 560 ll_init(); 561 #endif 562 #ifdef CONFIG_BT_HCIUART_ATH3K 563 ath_init(); 564 #endif 565 566 return 0; 567 } 568 569 static void __exit hci_uart_exit(void) 570 { 571 int err; 572 573 #ifdef CONFIG_BT_HCIUART_H4 574 h4_deinit(); 575 #endif 576 #ifdef CONFIG_BT_HCIUART_BCSP 577 bcsp_deinit(); 578 #endif 579 #ifdef CONFIG_BT_HCIUART_LL 580 ll_deinit(); 581 #endif 582 #ifdef CONFIG_BT_HCIUART_ATH3K 583 ath_deinit(); 584 #endif 585 586 /* Release tty registration of line discipline */ 587 if ((err = tty_unregister_ldisc(N_HCI))) 588 BT_ERR("Can't unregister HCI line discipline (%d)", err); 589 } 590 591 module_init(hci_uart_init); 592 module_exit(hci_uart_exit); 593 594 module_param(reset, bool, 0644); 595 MODULE_PARM_DESC(reset, "Send HCI reset command on initialization"); 596 597 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>"); 598 MODULE_DESCRIPTION("Bluetooth HCI UART driver ver " VERSION); 599 MODULE_VERSION(VERSION); 600 MODULE_LICENSE("GPL"); 601 MODULE_ALIAS_LDISC(N_HCI); 602