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 tty_struct *tty; 214 struct hci_uart *hu; 215 216 if (!hdev) { 217 BT_ERR("Frame for uknown device (hdev=NULL)"); 218 return -ENODEV; 219 } 220 221 if (!test_bit(HCI_RUNNING, &hdev->flags)) 222 return -EBUSY; 223 224 hu = (struct hci_uart *) hdev->driver_data; 225 tty = hu->tty; 226 227 BT_DBG("%s: type %d len %d", hdev->name, bt_cb(skb)->pkt_type, skb->len); 228 229 hu->proto->enqueue(hu, skb); 230 231 hci_uart_tx_wakeup(hu); 232 233 return 0; 234 } 235 236 static void hci_uart_destruct(struct hci_dev *hdev) 237 { 238 if (!hdev) 239 return; 240 241 BT_DBG("%s", hdev->name); 242 kfree(hdev->driver_data); 243 } 244 245 /* ------ LDISC part ------ */ 246 /* hci_uart_tty_open 247 * 248 * Called when line discipline changed to HCI_UART. 249 * 250 * Arguments: 251 * tty pointer to tty info structure 252 * Return Value: 253 * 0 if success, otherwise error code 254 */ 255 static int hci_uart_tty_open(struct tty_struct *tty) 256 { 257 struct hci_uart *hu = (void *) tty->disc_data; 258 259 BT_DBG("tty %p", tty); 260 261 if (hu) 262 return -EEXIST; 263 264 if (!(hu = kzalloc(sizeof(struct hci_uart), GFP_KERNEL))) { 265 BT_ERR("Can't allocate control structure"); 266 return -ENFILE; 267 } 268 269 tty->disc_data = hu; 270 hu->tty = tty; 271 tty->receive_room = 65536; 272 273 spin_lock_init(&hu->rx_lock); 274 275 /* Flush any pending characters in the driver and line discipline. */ 276 277 /* FIXME: why is this needed. Note don't use ldisc_ref here as the 278 open path is before the ldisc is referencable */ 279 280 if (tty->ldisc.ops->flush_buffer) 281 tty->ldisc.ops->flush_buffer(tty); 282 tty_driver_flush_buffer(tty); 283 284 return 0; 285 } 286 287 /* hci_uart_tty_close() 288 * 289 * Called when the line discipline is changed to something 290 * else, the tty is closed, or the tty detects a hangup. 291 */ 292 static void hci_uart_tty_close(struct tty_struct *tty) 293 { 294 struct hci_uart *hu = (void *)tty->disc_data; 295 296 BT_DBG("tty %p", tty); 297 298 /* Detach from the tty */ 299 tty->disc_data = NULL; 300 301 if (hu) { 302 struct hci_dev *hdev = hu->hdev; 303 304 if (hdev) 305 hci_uart_close(hdev); 306 307 if (test_and_clear_bit(HCI_UART_PROTO_SET, &hu->flags)) { 308 hu->proto->close(hu); 309 hci_unregister_dev(hdev); 310 hci_free_dev(hdev); 311 } 312 } 313 } 314 315 /* hci_uart_tty_wakeup() 316 * 317 * Callback for transmit wakeup. Called when low level 318 * device driver can accept more send data. 319 * 320 * Arguments: tty pointer to associated tty instance data 321 * Return Value: None 322 */ 323 static void hci_uart_tty_wakeup(struct tty_struct *tty) 324 { 325 struct hci_uart *hu = (void *)tty->disc_data; 326 327 BT_DBG(""); 328 329 if (!hu) 330 return; 331 332 clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); 333 334 if (tty != hu->tty) 335 return; 336 337 if (test_bit(HCI_UART_PROTO_SET, &hu->flags)) 338 hci_uart_tx_wakeup(hu); 339 } 340 341 /* hci_uart_tty_receive() 342 * 343 * Called by tty low level driver when receive data is 344 * available. 345 * 346 * Arguments: tty pointer to tty isntance data 347 * data pointer to received data 348 * flags pointer to flags for data 349 * count count of received data in bytes 350 * 351 * Return Value: None 352 */ 353 static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data, char *flags, int count) 354 { 355 struct hci_uart *hu = (void *)tty->disc_data; 356 357 if (!hu || tty != hu->tty) 358 return; 359 360 if (!test_bit(HCI_UART_PROTO_SET, &hu->flags)) 361 return; 362 363 spin_lock(&hu->rx_lock); 364 hu->proto->recv(hu, (void *) data, count); 365 hu->hdev->stat.byte_rx += count; 366 spin_unlock(&hu->rx_lock); 367 368 tty_unthrottle(tty); 369 } 370 371 static int hci_uart_register_dev(struct hci_uart *hu) 372 { 373 struct hci_dev *hdev; 374 375 BT_DBG(""); 376 377 /* Initialize and register HCI device */ 378 hdev = hci_alloc_dev(); 379 if (!hdev) { 380 BT_ERR("Can't allocate HCI device"); 381 return -ENOMEM; 382 } 383 384 hu->hdev = hdev; 385 386 hdev->type = HCI_UART; 387 hdev->driver_data = hu; 388 389 hdev->open = hci_uart_open; 390 hdev->close = hci_uart_close; 391 hdev->flush = hci_uart_flush; 392 hdev->send = hci_uart_send_frame; 393 hdev->destruct = hci_uart_destruct; 394 395 hdev->owner = THIS_MODULE; 396 397 if (!reset) 398 set_bit(HCI_QUIRK_NO_RESET, &hdev->quirks); 399 400 if (hci_register_dev(hdev) < 0) { 401 BT_ERR("Can't register HCI device"); 402 hci_free_dev(hdev); 403 return -ENODEV; 404 } 405 406 return 0; 407 } 408 409 static int hci_uart_set_proto(struct hci_uart *hu, int id) 410 { 411 struct hci_uart_proto *p; 412 int err; 413 414 p = hci_uart_get_proto(id); 415 if (!p) 416 return -EPROTONOSUPPORT; 417 418 err = p->open(hu); 419 if (err) 420 return err; 421 422 hu->proto = p; 423 424 err = hci_uart_register_dev(hu); 425 if (err) { 426 p->close(hu); 427 return err; 428 } 429 430 return 0; 431 } 432 433 /* hci_uart_tty_ioctl() 434 * 435 * Process IOCTL system call for the tty device. 436 * 437 * Arguments: 438 * 439 * tty pointer to tty instance data 440 * file pointer to open file object for device 441 * cmd IOCTL command code 442 * arg argument for IOCTL call (cmd dependent) 443 * 444 * Return Value: Command dependent 445 */ 446 static int hci_uart_tty_ioctl(struct tty_struct *tty, struct file * file, 447 unsigned int cmd, unsigned long arg) 448 { 449 struct hci_uart *hu = (void *)tty->disc_data; 450 int err = 0; 451 452 BT_DBG(""); 453 454 /* Verify the status of the device */ 455 if (!hu) 456 return -EBADF; 457 458 switch (cmd) { 459 case HCIUARTSETPROTO: 460 if (!test_and_set_bit(HCI_UART_PROTO_SET, &hu->flags)) { 461 err = hci_uart_set_proto(hu, arg); 462 if (err) { 463 clear_bit(HCI_UART_PROTO_SET, &hu->flags); 464 return err; 465 } 466 tty->low_latency = 1; 467 } else 468 return -EBUSY; 469 break; 470 471 case HCIUARTGETPROTO: 472 if (test_bit(HCI_UART_PROTO_SET, &hu->flags)) 473 return hu->proto->id; 474 return -EUNATCH; 475 476 case HCIUARTGETDEVICE: 477 if (test_bit(HCI_UART_PROTO_SET, &hu->flags)) 478 return hu->hdev->id; 479 return -EUNATCH; 480 481 default: 482 err = n_tty_ioctl_helper(tty, file, cmd, arg); 483 break; 484 }; 485 486 return err; 487 } 488 489 /* 490 * We don't provide read/write/poll interface for user space. 491 */ 492 static ssize_t hci_uart_tty_read(struct tty_struct *tty, struct file *file, 493 unsigned char __user *buf, size_t nr) 494 { 495 return 0; 496 } 497 498 static ssize_t hci_uart_tty_write(struct tty_struct *tty, struct file *file, 499 const unsigned char *data, size_t count) 500 { 501 return 0; 502 } 503 504 static unsigned int hci_uart_tty_poll(struct tty_struct *tty, 505 struct file *filp, poll_table *wait) 506 { 507 return 0; 508 } 509 510 static int __init hci_uart_init(void) 511 { 512 static struct tty_ldisc_ops hci_uart_ldisc; 513 int err; 514 515 BT_INFO("HCI UART driver ver %s", VERSION); 516 517 /* Register the tty discipline */ 518 519 memset(&hci_uart_ldisc, 0, sizeof (hci_uart_ldisc)); 520 hci_uart_ldisc.magic = TTY_LDISC_MAGIC; 521 hci_uart_ldisc.name = "n_hci"; 522 hci_uart_ldisc.open = hci_uart_tty_open; 523 hci_uart_ldisc.close = hci_uart_tty_close; 524 hci_uart_ldisc.read = hci_uart_tty_read; 525 hci_uart_ldisc.write = hci_uart_tty_write; 526 hci_uart_ldisc.ioctl = hci_uart_tty_ioctl; 527 hci_uart_ldisc.poll = hci_uart_tty_poll; 528 hci_uart_ldisc.receive_buf = hci_uart_tty_receive; 529 hci_uart_ldisc.write_wakeup = hci_uart_tty_wakeup; 530 hci_uart_ldisc.owner = THIS_MODULE; 531 532 if ((err = tty_register_ldisc(N_HCI, &hci_uart_ldisc))) { 533 BT_ERR("HCI line discipline registration failed. (%d)", err); 534 return err; 535 } 536 537 #ifdef CONFIG_BT_HCIUART_H4 538 h4_init(); 539 #endif 540 #ifdef CONFIG_BT_HCIUART_BCSP 541 bcsp_init(); 542 #endif 543 #ifdef CONFIG_BT_HCIUART_LL 544 ll_init(); 545 #endif 546 547 return 0; 548 } 549 550 static void __exit hci_uart_exit(void) 551 { 552 int err; 553 554 #ifdef CONFIG_BT_HCIUART_H4 555 h4_deinit(); 556 #endif 557 #ifdef CONFIG_BT_HCIUART_BCSP 558 bcsp_deinit(); 559 #endif 560 #ifdef CONFIG_BT_HCIUART_LL 561 ll_deinit(); 562 #endif 563 564 /* Release tty registration of line discipline */ 565 if ((err = tty_unregister_ldisc(N_HCI))) 566 BT_ERR("Can't unregister HCI line discipline (%d)", err); 567 } 568 569 module_init(hci_uart_init); 570 module_exit(hci_uart_exit); 571 572 module_param(reset, bool, 0644); 573 MODULE_PARM_DESC(reset, "Send HCI reset command on initialization"); 574 575 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>"); 576 MODULE_DESCRIPTION("Bluetooth HCI UART driver ver " VERSION); 577 MODULE_VERSION(VERSION); 578 MODULE_LICENSE("GPL"); 579 MODULE_ALIAS_LDISC(N_HCI); 580