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 #ifndef CONFIG_BT_HCIUART_DEBUG 50 #undef BT_DBG 51 #define BT_DBG( A... ) 52 #endif 53 54 #define VERSION "2.2" 55 56 static int reset = 0; 57 58 static struct hci_uart_proto *hup[HCI_UART_MAX_PROTO]; 59 60 int hci_uart_register_proto(struct hci_uart_proto *p) 61 { 62 if (p->id >= HCI_UART_MAX_PROTO) 63 return -EINVAL; 64 65 if (hup[p->id]) 66 return -EEXIST; 67 68 hup[p->id] = p; 69 70 return 0; 71 } 72 73 int hci_uart_unregister_proto(struct hci_uart_proto *p) 74 { 75 if (p->id >= HCI_UART_MAX_PROTO) 76 return -EINVAL; 77 78 if (!hup[p->id]) 79 return -EINVAL; 80 81 hup[p->id] = NULL; 82 83 return 0; 84 } 85 86 static struct hci_uart_proto *hci_uart_get_proto(unsigned int id) 87 { 88 if (id >= HCI_UART_MAX_PROTO) 89 return NULL; 90 91 return hup[id]; 92 } 93 94 static inline void hci_uart_tx_complete(struct hci_uart *hu, int pkt_type) 95 { 96 struct hci_dev *hdev = hu->hdev; 97 98 /* Update HCI stat counters */ 99 switch (pkt_type) { 100 case HCI_COMMAND_PKT: 101 hdev->stat.cmd_tx++; 102 break; 103 104 case HCI_ACLDATA_PKT: 105 hdev->stat.acl_tx++; 106 break; 107 108 case HCI_SCODATA_PKT: 109 hdev->stat.cmd_tx++; 110 break; 111 } 112 } 113 114 static inline struct sk_buff *hci_uart_dequeue(struct hci_uart *hu) 115 { 116 struct sk_buff *skb = hu->tx_skb; 117 118 if (!skb) 119 skb = hu->proto->dequeue(hu); 120 else 121 hu->tx_skb = NULL; 122 123 return skb; 124 } 125 126 int hci_uart_tx_wakeup(struct hci_uart *hu) 127 { 128 struct tty_struct *tty = hu->tty; 129 struct hci_dev *hdev = hu->hdev; 130 struct sk_buff *skb; 131 132 if (test_and_set_bit(HCI_UART_SENDING, &hu->tx_state)) { 133 set_bit(HCI_UART_TX_WAKEUP, &hu->tx_state); 134 return 0; 135 } 136 137 BT_DBG(""); 138 139 restart: 140 clear_bit(HCI_UART_TX_WAKEUP, &hu->tx_state); 141 142 while ((skb = hci_uart_dequeue(hu))) { 143 int len; 144 145 set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); 146 len = tty->driver->write(tty, skb->data, skb->len); 147 hdev->stat.byte_tx += len; 148 149 skb_pull(skb, len); 150 if (skb->len) { 151 hu->tx_skb = skb; 152 break; 153 } 154 155 hci_uart_tx_complete(hu, bt_cb(skb)->pkt_type); 156 kfree_skb(skb); 157 } 158 159 if (test_bit(HCI_UART_TX_WAKEUP, &hu->tx_state)) 160 goto restart; 161 162 clear_bit(HCI_UART_SENDING, &hu->tx_state); 163 return 0; 164 } 165 166 /* ------- Interface to HCI layer ------ */ 167 /* Initialize device */ 168 static int hci_uart_open(struct hci_dev *hdev) 169 { 170 BT_DBG("%s %p", hdev->name, hdev); 171 172 /* Nothing to do for UART driver */ 173 174 set_bit(HCI_RUNNING, &hdev->flags); 175 176 return 0; 177 } 178 179 /* Reset device */ 180 static int hci_uart_flush(struct hci_dev *hdev) 181 { 182 struct hci_uart *hu = (struct hci_uart *) hdev->driver_data; 183 struct tty_struct *tty = hu->tty; 184 185 BT_DBG("hdev %p tty %p", hdev, tty); 186 187 if (hu->tx_skb) { 188 kfree_skb(hu->tx_skb); hu->tx_skb = NULL; 189 } 190 191 /* Flush any pending characters in the driver and discipline. */ 192 tty_ldisc_flush(tty); 193 if (tty->driver && tty->driver->flush_buffer) 194 tty->driver->flush_buffer(tty); 195 196 if (test_bit(HCI_UART_PROTO_SET, &hu->flags)) 197 hu->proto->flush(hu); 198 199 return 0; 200 } 201 202 /* Close device */ 203 static int hci_uart_close(struct hci_dev *hdev) 204 { 205 BT_DBG("hdev %p", hdev); 206 207 if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags)) 208 return 0; 209 210 hci_uart_flush(hdev); 211 hdev->flush = NULL; 212 return 0; 213 } 214 215 /* Send frames from HCI layer */ 216 static int hci_uart_send_frame(struct sk_buff *skb) 217 { 218 struct hci_dev* hdev = (struct hci_dev *) skb->dev; 219 struct tty_struct *tty; 220 struct hci_uart *hu; 221 222 if (!hdev) { 223 BT_ERR("Frame for uknown device (hdev=NULL)"); 224 return -ENODEV; 225 } 226 227 if (!test_bit(HCI_RUNNING, &hdev->flags)) 228 return -EBUSY; 229 230 hu = (struct hci_uart *) hdev->driver_data; 231 tty = hu->tty; 232 233 BT_DBG("%s: type %d len %d", hdev->name, bt_cb(skb)->pkt_type, skb->len); 234 235 hu->proto->enqueue(hu, skb); 236 237 hci_uart_tx_wakeup(hu); 238 239 return 0; 240 } 241 242 static void hci_uart_destruct(struct hci_dev *hdev) 243 { 244 if (!hdev) 245 return; 246 247 BT_DBG("%s", hdev->name); 248 kfree(hdev->driver_data); 249 } 250 251 /* ------ LDISC part ------ */ 252 /* hci_uart_tty_open 253 * 254 * Called when line discipline changed to HCI_UART. 255 * 256 * Arguments: 257 * tty pointer to tty info structure 258 * Return Value: 259 * 0 if success, otherwise error code 260 */ 261 static int hci_uart_tty_open(struct tty_struct *tty) 262 { 263 struct hci_uart *hu = (void *) tty->disc_data; 264 265 BT_DBG("tty %p", tty); 266 267 if (hu) 268 return -EEXIST; 269 270 if (!(hu = kzalloc(sizeof(struct hci_uart), GFP_KERNEL))) { 271 BT_ERR("Can't allocate control structure"); 272 return -ENFILE; 273 } 274 275 tty->disc_data = hu; 276 hu->tty = tty; 277 tty->receive_room = 65536; 278 279 spin_lock_init(&hu->rx_lock); 280 281 /* Flush any pending characters in the driver and line discipline. */ 282 283 /* FIXME: why is this needed. Note don't use ldisc_ref here as the 284 open path is before the ldisc is referencable */ 285 286 if (tty->ldisc.flush_buffer) 287 tty->ldisc.flush_buffer(tty); 288 289 if (tty->driver && tty->driver->flush_buffer) 290 tty->driver->flush_buffer(tty); 291 292 return 0; 293 } 294 295 /* hci_uart_tty_close() 296 * 297 * Called when the line discipline is changed to something 298 * else, the tty is closed, or the tty detects a hangup. 299 */ 300 static void hci_uart_tty_close(struct tty_struct *tty) 301 { 302 struct hci_uart *hu = (void *)tty->disc_data; 303 304 BT_DBG("tty %p", tty); 305 306 /* Detach from the tty */ 307 tty->disc_data = NULL; 308 309 if (hu) { 310 struct hci_dev *hdev = hu->hdev; 311 312 if (hdev) 313 hci_uart_close(hdev); 314 315 if (test_and_clear_bit(HCI_UART_PROTO_SET, &hu->flags)) { 316 hu->proto->close(hu); 317 hci_unregister_dev(hdev); 318 hci_free_dev(hdev); 319 } 320 } 321 } 322 323 /* hci_uart_tty_wakeup() 324 * 325 * Callback for transmit wakeup. Called when low level 326 * device driver can accept more send data. 327 * 328 * Arguments: tty pointer to associated tty instance data 329 * Return Value: None 330 */ 331 static void hci_uart_tty_wakeup(struct tty_struct *tty) 332 { 333 struct hci_uart *hu = (void *)tty->disc_data; 334 335 BT_DBG(""); 336 337 if (!hu) 338 return; 339 340 clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); 341 342 if (tty != hu->tty) 343 return; 344 345 if (test_bit(HCI_UART_PROTO_SET, &hu->flags)) 346 hci_uart_tx_wakeup(hu); 347 } 348 349 /* hci_uart_tty_receive() 350 * 351 * Called by tty low level driver when receive data is 352 * available. 353 * 354 * Arguments: tty pointer to tty isntance data 355 * data pointer to received data 356 * flags pointer to flags for data 357 * count count of received data in bytes 358 * 359 * Return Value: None 360 */ 361 static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data, char *flags, int count) 362 { 363 struct hci_uart *hu = (void *)tty->disc_data; 364 365 if (!hu || tty != hu->tty) 366 return; 367 368 if (!test_bit(HCI_UART_PROTO_SET, &hu->flags)) 369 return; 370 371 spin_lock(&hu->rx_lock); 372 hu->proto->recv(hu, (void *) data, count); 373 hu->hdev->stat.byte_rx += count; 374 spin_unlock(&hu->rx_lock); 375 376 if (test_and_clear_bit(TTY_THROTTLED, &tty->flags) && 377 tty->driver->unthrottle) 378 tty->driver->unthrottle(tty); 379 } 380 381 static int hci_uart_register_dev(struct hci_uart *hu) 382 { 383 struct hci_dev *hdev; 384 385 BT_DBG(""); 386 387 /* Initialize and register HCI device */ 388 hdev = hci_alloc_dev(); 389 if (!hdev) { 390 BT_ERR("Can't allocate HCI device"); 391 return -ENOMEM; 392 } 393 394 hu->hdev = hdev; 395 396 hdev->type = HCI_UART; 397 hdev->driver_data = hu; 398 399 hdev->open = hci_uart_open; 400 hdev->close = hci_uart_close; 401 hdev->flush = hci_uart_flush; 402 hdev->send = hci_uart_send_frame; 403 hdev->destruct = hci_uart_destruct; 404 405 hdev->owner = THIS_MODULE; 406 407 if (reset) 408 set_bit(HCI_QUIRK_RESET_ON_INIT, &hdev->quirks); 409 410 if (hci_register_dev(hdev) < 0) { 411 BT_ERR("Can't register HCI device"); 412 hci_free_dev(hdev); 413 return -ENODEV; 414 } 415 416 return 0; 417 } 418 419 static int hci_uart_set_proto(struct hci_uart *hu, int id) 420 { 421 struct hci_uart_proto *p; 422 int err; 423 424 p = hci_uart_get_proto(id); 425 if (!p) 426 return -EPROTONOSUPPORT; 427 428 err = p->open(hu); 429 if (err) 430 return err; 431 432 hu->proto = p; 433 434 err = hci_uart_register_dev(hu); 435 if (err) { 436 p->close(hu); 437 return err; 438 } 439 440 return 0; 441 } 442 443 /* hci_uart_tty_ioctl() 444 * 445 * Process IOCTL system call for the tty device. 446 * 447 * Arguments: 448 * 449 * tty pointer to tty instance data 450 * file pointer to open file object for device 451 * cmd IOCTL command code 452 * arg argument for IOCTL call (cmd dependent) 453 * 454 * Return Value: Command dependent 455 */ 456 static int hci_uart_tty_ioctl(struct tty_struct *tty, struct file * file, 457 unsigned int cmd, unsigned long arg) 458 { 459 struct hci_uart *hu = (void *)tty->disc_data; 460 int err = 0; 461 462 BT_DBG(""); 463 464 /* Verify the status of the device */ 465 if (!hu) 466 return -EBADF; 467 468 switch (cmd) { 469 case HCIUARTSETPROTO: 470 if (!test_and_set_bit(HCI_UART_PROTO_SET, &hu->flags)) { 471 err = hci_uart_set_proto(hu, arg); 472 if (err) { 473 clear_bit(HCI_UART_PROTO_SET, &hu->flags); 474 return err; 475 } 476 tty->low_latency = 1; 477 } else 478 return -EBUSY; 479 break; 480 481 case HCIUARTGETPROTO: 482 if (test_bit(HCI_UART_PROTO_SET, &hu->flags)) 483 return hu->proto->id; 484 return -EUNATCH; 485 486 case HCIUARTGETDEVICE: 487 if (test_bit(HCI_UART_PROTO_SET, &hu->flags)) 488 return hu->hdev->id; 489 return -EUNATCH; 490 491 default: 492 err = n_tty_ioctl(tty, file, cmd, arg); 493 break; 494 }; 495 496 return err; 497 } 498 499 /* 500 * We don't provide read/write/poll interface for user space. 501 */ 502 static ssize_t hci_uart_tty_read(struct tty_struct *tty, struct file *file, 503 unsigned char __user *buf, size_t nr) 504 { 505 return 0; 506 } 507 508 static ssize_t hci_uart_tty_write(struct tty_struct *tty, struct file *file, 509 const unsigned char *data, size_t count) 510 { 511 return 0; 512 } 513 514 static unsigned int hci_uart_tty_poll(struct tty_struct *tty, 515 struct file *filp, poll_table *wait) 516 { 517 return 0; 518 } 519 520 static int __init hci_uart_init(void) 521 { 522 static struct tty_ldisc hci_uart_ldisc; 523 int err; 524 525 BT_INFO("HCI UART driver ver %s", VERSION); 526 527 /* Register the tty discipline */ 528 529 memset(&hci_uart_ldisc, 0, sizeof (hci_uart_ldisc)); 530 hci_uart_ldisc.magic = TTY_LDISC_MAGIC; 531 hci_uart_ldisc.name = "n_hci"; 532 hci_uart_ldisc.open = hci_uart_tty_open; 533 hci_uart_ldisc.close = hci_uart_tty_close; 534 hci_uart_ldisc.read = hci_uart_tty_read; 535 hci_uart_ldisc.write = hci_uart_tty_write; 536 hci_uart_ldisc.ioctl = hci_uart_tty_ioctl; 537 hci_uart_ldisc.poll = hci_uart_tty_poll; 538 hci_uart_ldisc.receive_buf = hci_uart_tty_receive; 539 hci_uart_ldisc.write_wakeup = hci_uart_tty_wakeup; 540 hci_uart_ldisc.owner = THIS_MODULE; 541 542 if ((err = tty_register_ldisc(N_HCI, &hci_uart_ldisc))) { 543 BT_ERR("HCI line discipline registration failed. (%d)", err); 544 return err; 545 } 546 547 #ifdef CONFIG_BT_HCIUART_H4 548 h4_init(); 549 #endif 550 #ifdef CONFIG_BT_HCIUART_BCSP 551 bcsp_init(); 552 #endif 553 #ifdef CONFIG_BT_HCIUART_LL 554 ll_init(); 555 #endif 556 557 return 0; 558 } 559 560 static void __exit hci_uart_exit(void) 561 { 562 int err; 563 564 #ifdef CONFIG_BT_HCIUART_H4 565 h4_deinit(); 566 #endif 567 #ifdef CONFIG_BT_HCIUART_BCSP 568 bcsp_deinit(); 569 #endif 570 #ifdef CONFIG_BT_HCIUART_LL 571 ll_deinit(); 572 #endif 573 574 /* Release tty registration of line discipline */ 575 if ((err = tty_unregister_ldisc(N_HCI))) 576 BT_ERR("Can't unregister HCI line discipline (%d)", err); 577 } 578 579 module_init(hci_uart_init); 580 module_exit(hci_uart_exit); 581 582 module_param(reset, bool, 0644); 583 MODULE_PARM_DESC(reset, "Send HCI reset command on initialization"); 584 585 MODULE_AUTHOR("Maxim Krasnyansky <maxk@qualcomm.com>, Marcel Holtmann <marcel@holtmann.org>"); 586 MODULE_DESCRIPTION("Bluetooth HCI UART driver ver " VERSION); 587 MODULE_VERSION(VERSION); 588 MODULE_LICENSE("GPL"); 589 MODULE_ALIAS_LDISC(N_HCI); 590