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 return 0; 212 } 213 214 /* Send frames from HCI layer */ 215 static int hci_uart_send_frame(struct sk_buff *skb) 216 { 217 struct hci_dev* hdev = (struct hci_dev *) skb->dev; 218 struct tty_struct *tty; 219 struct hci_uart *hu; 220 221 if (!hdev) { 222 BT_ERR("Frame for uknown device (hdev=NULL)"); 223 return -ENODEV; 224 } 225 226 if (!test_bit(HCI_RUNNING, &hdev->flags)) 227 return -EBUSY; 228 229 hu = (struct hci_uart *) hdev->driver_data; 230 tty = hu->tty; 231 232 BT_DBG("%s: type %d len %d", hdev->name, bt_cb(skb)->pkt_type, skb->len); 233 234 hu->proto->enqueue(hu, skb); 235 236 hci_uart_tx_wakeup(hu); 237 238 return 0; 239 } 240 241 static void hci_uart_destruct(struct hci_dev *hdev) 242 { 243 if (!hdev) 244 return; 245 246 BT_DBG("%s", hdev->name); 247 kfree(hdev->driver_data); 248 } 249 250 /* ------ LDISC part ------ */ 251 /* hci_uart_tty_open 252 * 253 * Called when line discipline changed to HCI_UART. 254 * 255 * Arguments: 256 * tty pointer to tty info structure 257 * Return Value: 258 * 0 if success, otherwise error code 259 */ 260 static int hci_uart_tty_open(struct tty_struct *tty) 261 { 262 struct hci_uart *hu = (void *) tty->disc_data; 263 264 BT_DBG("tty %p", tty); 265 266 if (hu) 267 return -EEXIST; 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.flush_buffer) 286 tty->ldisc.flush_buffer(tty); 287 288 if (tty->driver && tty->driver->flush_buffer) 289 tty->driver->flush_buffer(tty); 290 291 return 0; 292 } 293 294 /* hci_uart_tty_close() 295 * 296 * Called when the line discipline is changed to something 297 * else, the tty is closed, or the tty detects a hangup. 298 */ 299 static void hci_uart_tty_close(struct tty_struct *tty) 300 { 301 struct hci_uart *hu = (void *)tty->disc_data; 302 303 BT_DBG("tty %p", tty); 304 305 /* Detach from the tty */ 306 tty->disc_data = NULL; 307 308 if (hu) { 309 struct hci_dev *hdev = hu->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 if (test_and_clear_bit(TTY_THROTTLED, &tty->flags) && 374 tty->driver->unthrottle) 375 tty->driver->unthrottle(tty); 376 } 377 378 static int hci_uart_register_dev(struct hci_uart *hu) 379 { 380 struct hci_dev *hdev; 381 382 BT_DBG(""); 383 384 /* Initialize and register HCI device */ 385 hdev = hci_alloc_dev(); 386 if (!hdev) { 387 BT_ERR("Can't allocate HCI device"); 388 return -ENOMEM; 389 } 390 391 hu->hdev = hdev; 392 393 hdev->type = HCI_UART; 394 hdev->driver_data = hu; 395 396 hdev->open = hci_uart_open; 397 hdev->close = hci_uart_close; 398 hdev->flush = hci_uart_flush; 399 hdev->send = hci_uart_send_frame; 400 hdev->destruct = hci_uart_destruct; 401 402 hdev->owner = THIS_MODULE; 403 404 if (reset) 405 set_bit(HCI_QUIRK_RESET_ON_INIT, &hdev->quirks); 406 407 if (hci_register_dev(hdev) < 0) { 408 BT_ERR("Can't register HCI device"); 409 hci_free_dev(hdev); 410 return -ENODEV; 411 } 412 413 return 0; 414 } 415 416 static int hci_uart_set_proto(struct hci_uart *hu, int id) 417 { 418 struct hci_uart_proto *p; 419 int err; 420 421 p = hci_uart_get_proto(id); 422 if (!p) 423 return -EPROTONOSUPPORT; 424 425 err = p->open(hu); 426 if (err) 427 return err; 428 429 hu->proto = p; 430 431 err = hci_uart_register_dev(hu); 432 if (err) { 433 p->close(hu); 434 return err; 435 } 436 437 return 0; 438 } 439 440 /* hci_uart_tty_ioctl() 441 * 442 * Process IOCTL system call for the tty device. 443 * 444 * Arguments: 445 * 446 * tty pointer to tty instance data 447 * file pointer to open file object for device 448 * cmd IOCTL command code 449 * arg argument for IOCTL call (cmd dependent) 450 * 451 * Return Value: Command dependent 452 */ 453 static int hci_uart_tty_ioctl(struct tty_struct *tty, struct file * file, 454 unsigned int cmd, unsigned long arg) 455 { 456 struct hci_uart *hu = (void *)tty->disc_data; 457 int err = 0; 458 459 BT_DBG(""); 460 461 /* Verify the status of the device */ 462 if (!hu) 463 return -EBADF; 464 465 switch (cmd) { 466 case HCIUARTSETPROTO: 467 if (!test_and_set_bit(HCI_UART_PROTO_SET, &hu->flags)) { 468 err = hci_uart_set_proto(hu, arg); 469 if (err) { 470 clear_bit(HCI_UART_PROTO_SET, &hu->flags); 471 return err; 472 } 473 tty->low_latency = 1; 474 } else 475 return -EBUSY; 476 477 case HCIUARTGETPROTO: 478 if (test_bit(HCI_UART_PROTO_SET, &hu->flags)) 479 return hu->proto->id; 480 return -EUNATCH; 481 482 default: 483 err = n_tty_ioctl(tty, file, cmd, arg); 484 break; 485 }; 486 487 return err; 488 } 489 490 /* 491 * We don't provide read/write/poll interface for user space. 492 */ 493 static ssize_t hci_uart_tty_read(struct tty_struct *tty, struct file *file, 494 unsigned char __user *buf, size_t nr) 495 { 496 return 0; 497 } 498 499 static ssize_t hci_uart_tty_write(struct tty_struct *tty, struct file *file, 500 const unsigned char *data, size_t count) 501 { 502 return 0; 503 } 504 505 static unsigned int hci_uart_tty_poll(struct tty_struct *tty, 506 struct file *filp, poll_table *wait) 507 { 508 return 0; 509 } 510 511 static int __init hci_uart_init(void) 512 { 513 static struct tty_ldisc hci_uart_ldisc; 514 int err; 515 516 BT_INFO("HCI UART driver ver %s", VERSION); 517 518 /* Register the tty discipline */ 519 520 memset(&hci_uart_ldisc, 0, sizeof (hci_uart_ldisc)); 521 hci_uart_ldisc.magic = TTY_LDISC_MAGIC; 522 hci_uart_ldisc.name = "n_hci"; 523 hci_uart_ldisc.open = hci_uart_tty_open; 524 hci_uart_ldisc.close = hci_uart_tty_close; 525 hci_uart_ldisc.read = hci_uart_tty_read; 526 hci_uart_ldisc.write = hci_uart_tty_write; 527 hci_uart_ldisc.ioctl = hci_uart_tty_ioctl; 528 hci_uart_ldisc.poll = hci_uart_tty_poll; 529 hci_uart_ldisc.receive_buf = hci_uart_tty_receive; 530 hci_uart_ldisc.write_wakeup = hci_uart_tty_wakeup; 531 hci_uart_ldisc.owner = THIS_MODULE; 532 533 if ((err = tty_register_ldisc(N_HCI, &hci_uart_ldisc))) { 534 BT_ERR("HCI line discipline registration failed. (%d)", err); 535 return err; 536 } 537 538 #ifdef CONFIG_BT_HCIUART_H4 539 h4_init(); 540 #endif 541 #ifdef CONFIG_BT_HCIUART_BCSP 542 bcsp_init(); 543 #endif 544 545 return 0; 546 } 547 548 static void __exit hci_uart_exit(void) 549 { 550 int err; 551 552 #ifdef CONFIG_BT_HCIUART_H4 553 h4_deinit(); 554 #endif 555 #ifdef CONFIG_BT_HCIUART_BCSP 556 bcsp_deinit(); 557 #endif 558 559 /* Release tty registration of line discipline */ 560 if ((err = tty_unregister_ldisc(N_HCI))) 561 BT_ERR("Can't unregister HCI line discipline (%d)", err); 562 } 563 564 module_init(hci_uart_init); 565 module_exit(hci_uart_exit); 566 567 module_param(reset, bool, 0644); 568 MODULE_PARM_DESC(reset, "Send HCI reset command on initialization"); 569 570 MODULE_AUTHOR("Maxim Krasnyansky <maxk@qualcomm.com>, Marcel Holtmann <marcel@holtmann.org>"); 571 MODULE_DESCRIPTION("Bluetooth HCI UART driver ver " VERSION); 572 MODULE_VERSION(VERSION); 573 MODULE_LICENSE("GPL"); 574 MODULE_ALIAS_LDISC(N_HCI); 575