1 /* 2 * USB Serial Converter Generic functions 3 * 4 * Copyright (C) 1999 - 2002 Greg Kroah-Hartman (greg@kroah.com) 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License version 8 * 2 as published by the Free Software Foundation. 9 * 10 */ 11 12 #include <linux/kernel.h> 13 #include <linux/errno.h> 14 #include <linux/slab.h> 15 #include <linux/tty.h> 16 #include <linux/tty_flip.h> 17 #include <linux/module.h> 18 #include <linux/moduleparam.h> 19 #include <linux/usb.h> 20 #include <linux/usb/serial.h> 21 #include <linux/uaccess.h> 22 23 24 static int debug; 25 26 #ifdef CONFIG_USB_SERIAL_GENERIC 27 28 static int generic_probe(struct usb_interface *interface, 29 const struct usb_device_id *id); 30 31 static __u16 vendor = 0x05f9; 32 static __u16 product = 0xffff; 33 34 module_param(vendor, ushort, 0); 35 MODULE_PARM_DESC(vendor, "User specified USB idVendor"); 36 37 module_param(product, ushort, 0); 38 MODULE_PARM_DESC(product, "User specified USB idProduct"); 39 40 static struct usb_device_id generic_device_ids[2]; /* Initially all zeroes. */ 41 42 /* we want to look at all devices, as the vendor/product id can change 43 * depending on the command line argument */ 44 static struct usb_device_id generic_serial_ids[] = { 45 {.driver_info = 42}, 46 {} 47 }; 48 49 static struct usb_driver generic_driver = { 50 .name = "usbserial_generic", 51 .probe = generic_probe, 52 .disconnect = usb_serial_disconnect, 53 .id_table = generic_serial_ids, 54 .no_dynamic_id = 1, 55 }; 56 57 /* All of the device info needed for the Generic Serial Converter */ 58 struct usb_serial_driver usb_serial_generic_device = { 59 .driver = { 60 .owner = THIS_MODULE, 61 .name = "generic", 62 }, 63 .id_table = generic_device_ids, 64 .usb_driver = &generic_driver, 65 .num_ports = 1, 66 .disconnect = usb_serial_generic_disconnect, 67 .release = usb_serial_generic_release, 68 .throttle = usb_serial_generic_throttle, 69 .unthrottle = usb_serial_generic_unthrottle, 70 .resume = usb_serial_generic_resume, 71 }; 72 73 static int generic_probe(struct usb_interface *interface, 74 const struct usb_device_id *id) 75 { 76 const struct usb_device_id *id_pattern; 77 78 id_pattern = usb_match_id(interface, generic_device_ids); 79 if (id_pattern != NULL) 80 return usb_serial_probe(interface, id); 81 return -ENODEV; 82 } 83 #endif 84 85 int usb_serial_generic_register(int _debug) 86 { 87 int retval = 0; 88 89 debug = _debug; 90 #ifdef CONFIG_USB_SERIAL_GENERIC 91 generic_device_ids[0].idVendor = vendor; 92 generic_device_ids[0].idProduct = product; 93 generic_device_ids[0].match_flags = 94 USB_DEVICE_ID_MATCH_VENDOR | USB_DEVICE_ID_MATCH_PRODUCT; 95 96 /* register our generic driver with ourselves */ 97 retval = usb_serial_register(&usb_serial_generic_device); 98 if (retval) 99 goto exit; 100 retval = usb_register(&generic_driver); 101 if (retval) 102 usb_serial_deregister(&usb_serial_generic_device); 103 exit: 104 #endif 105 return retval; 106 } 107 108 void usb_serial_generic_deregister(void) 109 { 110 #ifdef CONFIG_USB_SERIAL_GENERIC 111 /* remove our generic driver */ 112 usb_deregister(&generic_driver); 113 usb_serial_deregister(&usb_serial_generic_device); 114 #endif 115 } 116 117 int usb_serial_generic_open(struct tty_struct *tty, struct usb_serial_port *port) 118 { 119 struct usb_serial *serial = port->serial; 120 int result = 0; 121 unsigned long flags; 122 123 dbg("%s - port %d", __func__, port->number); 124 125 /* clear the throttle flags */ 126 spin_lock_irqsave(&port->lock, flags); 127 port->throttled = 0; 128 port->throttle_req = 0; 129 spin_unlock_irqrestore(&port->lock, flags); 130 131 /* if we have a bulk endpoint, start reading from it */ 132 if (serial->num_bulk_in) { 133 /* Start reading from the device */ 134 usb_fill_bulk_urb(port->read_urb, serial->dev, 135 usb_rcvbulkpipe(serial->dev, 136 port->bulk_in_endpointAddress), 137 port->read_urb->transfer_buffer, 138 port->read_urb->transfer_buffer_length, 139 ((serial->type->read_bulk_callback) ? 140 serial->type->read_bulk_callback : 141 usb_serial_generic_read_bulk_callback), 142 port); 143 result = usb_submit_urb(port->read_urb, GFP_KERNEL); 144 if (result) 145 dev_err(&port->dev, 146 "%s - failed resubmitting read urb, error %d\n", 147 __func__, result); 148 } 149 150 return result; 151 } 152 EXPORT_SYMBOL_GPL(usb_serial_generic_open); 153 154 static void generic_cleanup(struct usb_serial_port *port) 155 { 156 struct usb_serial *serial = port->serial; 157 158 dbg("%s - port %d", __func__, port->number); 159 160 if (serial->dev) { 161 /* shutdown any bulk reads that might be going on */ 162 if (serial->num_bulk_out) 163 usb_kill_urb(port->write_urb); 164 if (serial->num_bulk_in) 165 usb_kill_urb(port->read_urb); 166 } 167 } 168 169 int usb_serial_generic_resume(struct usb_serial *serial) 170 { 171 struct usb_serial_port *port; 172 int i, c = 0, r; 173 174 for (i = 0; i < serial->num_ports; i++) { 175 port = serial->port[i]; 176 if (port->port.count && port->read_urb) { 177 r = usb_submit_urb(port->read_urb, GFP_NOIO); 178 if (r < 0) 179 c++; 180 } 181 } 182 183 return c ? -EIO : 0; 184 } 185 EXPORT_SYMBOL_GPL(usb_serial_generic_resume); 186 187 void usb_serial_generic_close(struct usb_serial_port *port) 188 { 189 dbg("%s - port %d", __func__, port->number); 190 generic_cleanup(port); 191 } 192 193 static int usb_serial_multi_urb_write(struct tty_struct *tty, 194 struct usb_serial_port *port, const unsigned char *buf, int count) 195 { 196 unsigned long flags; 197 struct urb *urb; 198 unsigned char *buffer; 199 int status; 200 int towrite; 201 int bwrite = 0; 202 203 dbg("%s - port %d", __func__, port->number); 204 205 if (count == 0) 206 dbg("%s - write request of 0 bytes", __func__); 207 208 while (count > 0) { 209 towrite = (count > port->bulk_out_size) ? 210 port->bulk_out_size : count; 211 spin_lock_irqsave(&port->lock, flags); 212 if (port->urbs_in_flight > 213 port->serial->type->max_in_flight_urbs) { 214 spin_unlock_irqrestore(&port->lock, flags); 215 dbg("%s - write limit hit\n", __func__); 216 return bwrite; 217 } 218 port->tx_bytes_flight += towrite; 219 port->urbs_in_flight++; 220 spin_unlock_irqrestore(&port->lock, flags); 221 222 buffer = kmalloc(towrite, GFP_ATOMIC); 223 if (!buffer) { 224 dev_err(&port->dev, 225 "%s ran out of kernel memory for urb ...\n", __func__); 226 goto error_no_buffer; 227 } 228 229 urb = usb_alloc_urb(0, GFP_ATOMIC); 230 if (!urb) { 231 dev_err(&port->dev, "%s - no more free urbs\n", 232 __func__); 233 goto error_no_urb; 234 } 235 236 /* Copy data */ 237 memcpy(buffer, buf + bwrite, towrite); 238 usb_serial_debug_data(debug, &port->dev, __func__, 239 towrite, buffer); 240 /* fill the buffer and send it */ 241 usb_fill_bulk_urb(urb, port->serial->dev, 242 usb_sndbulkpipe(port->serial->dev, 243 port->bulk_out_endpointAddress), 244 buffer, towrite, 245 usb_serial_generic_write_bulk_callback, port); 246 247 status = usb_submit_urb(urb, GFP_ATOMIC); 248 if (status) { 249 dev_err(&port->dev, 250 "%s - failed submitting write urb, error %d\n", 251 __func__, status); 252 goto error; 253 } 254 255 /* This urb is the responsibility of the host driver now */ 256 usb_free_urb(urb); 257 dbg("%s write: %d", __func__, towrite); 258 count -= towrite; 259 bwrite += towrite; 260 } 261 return bwrite; 262 263 error: 264 usb_free_urb(urb); 265 error_no_urb: 266 kfree(buffer); 267 error_no_buffer: 268 spin_lock_irqsave(&port->lock, flags); 269 port->urbs_in_flight--; 270 port->tx_bytes_flight -= towrite; 271 spin_unlock_irqrestore(&port->lock, flags); 272 return bwrite; 273 } 274 275 int usb_serial_generic_write(struct tty_struct *tty, 276 struct usb_serial_port *port, const unsigned char *buf, int count) 277 { 278 struct usb_serial *serial = port->serial; 279 int result; 280 unsigned char *data; 281 282 dbg("%s - port %d", __func__, port->number); 283 284 if (count == 0) { 285 dbg("%s - write request of 0 bytes", __func__); 286 return 0; 287 } 288 289 /* only do something if we have a bulk out endpoint */ 290 if (serial->num_bulk_out) { 291 unsigned long flags; 292 293 if (serial->type->max_in_flight_urbs) 294 return usb_serial_multi_urb_write(tty, port, 295 buf, count); 296 297 spin_lock_irqsave(&port->lock, flags); 298 if (port->write_urb_busy) { 299 spin_unlock_irqrestore(&port->lock, flags); 300 dbg("%s - already writing", __func__); 301 return 0; 302 } 303 port->write_urb_busy = 1; 304 spin_unlock_irqrestore(&port->lock, flags); 305 306 count = (count > port->bulk_out_size) ? 307 port->bulk_out_size : count; 308 309 memcpy(port->write_urb->transfer_buffer, buf, count); 310 data = port->write_urb->transfer_buffer; 311 usb_serial_debug_data(debug, &port->dev, __func__, count, data); 312 313 /* set up our urb */ 314 usb_fill_bulk_urb(port->write_urb, serial->dev, 315 usb_sndbulkpipe(serial->dev, 316 port->bulk_out_endpointAddress), 317 port->write_urb->transfer_buffer, count, 318 ((serial->type->write_bulk_callback) ? 319 serial->type->write_bulk_callback : 320 usb_serial_generic_write_bulk_callback), 321 port); 322 323 /* send the data out the bulk port */ 324 port->write_urb_busy = 1; 325 result = usb_submit_urb(port->write_urb, GFP_ATOMIC); 326 if (result) { 327 dev_err(&port->dev, 328 "%s - failed submitting write urb, error %d\n", 329 __func__, result); 330 /* don't have to grab the lock here, as we will 331 retry if != 0 */ 332 port->write_urb_busy = 0; 333 } else 334 result = count; 335 336 return result; 337 } 338 339 /* no bulk out, so return 0 bytes written */ 340 return 0; 341 } 342 EXPORT_SYMBOL_GPL(usb_serial_generic_write); 343 344 int usb_serial_generic_write_room(struct tty_struct *tty) 345 { 346 struct usb_serial_port *port = tty->driver_data; 347 struct usb_serial *serial = port->serial; 348 unsigned long flags; 349 int room = 0; 350 351 dbg("%s - port %d", __func__, port->number); 352 spin_lock_irqsave(&port->lock, flags); 353 if (serial->type->max_in_flight_urbs) { 354 if (port->urbs_in_flight < serial->type->max_in_flight_urbs) 355 room = port->bulk_out_size * 356 (serial->type->max_in_flight_urbs - 357 port->urbs_in_flight); 358 } else if (serial->num_bulk_out && !(port->write_urb_busy)) { 359 room = port->bulk_out_size; 360 } 361 spin_unlock_irqrestore(&port->lock, flags); 362 363 dbg("%s - returns %d", __func__, room); 364 return room; 365 } 366 367 int usb_serial_generic_chars_in_buffer(struct tty_struct *tty) 368 { 369 struct usb_serial_port *port = tty->driver_data; 370 struct usb_serial *serial = port->serial; 371 int chars = 0; 372 unsigned long flags; 373 374 dbg("%s - port %d", __func__, port->number); 375 376 if (serial->type->max_in_flight_urbs) { 377 spin_lock_irqsave(&port->lock, flags); 378 chars = port->tx_bytes_flight; 379 spin_unlock_irqrestore(&port->lock, flags); 380 } else if (serial->num_bulk_out) { 381 /* FIXME: Locking */ 382 if (port->write_urb_busy) 383 chars = port->write_urb->transfer_buffer_length; 384 } 385 386 dbg("%s - returns %d", __func__, chars); 387 return chars; 388 } 389 390 391 void usb_serial_generic_resubmit_read_urb(struct usb_serial_port *port, 392 gfp_t mem_flags) 393 { 394 struct urb *urb = port->read_urb; 395 struct usb_serial *serial = port->serial; 396 int result; 397 398 /* Continue reading from device */ 399 usb_fill_bulk_urb(urb, serial->dev, 400 usb_rcvbulkpipe(serial->dev, 401 port->bulk_in_endpointAddress), 402 urb->transfer_buffer, 403 urb->transfer_buffer_length, 404 ((serial->type->read_bulk_callback) ? 405 serial->type->read_bulk_callback : 406 usb_serial_generic_read_bulk_callback), port); 407 result = usb_submit_urb(urb, mem_flags); 408 if (result) 409 dev_err(&port->dev, 410 "%s - failed resubmitting read urb, error %d\n", 411 __func__, result); 412 } 413 EXPORT_SYMBOL_GPL(usb_serial_generic_resubmit_read_urb); 414 415 /* Push data to tty layer and resubmit the bulk read URB */ 416 static void flush_and_resubmit_read_urb(struct usb_serial_port *port) 417 { 418 struct urb *urb = port->read_urb; 419 struct tty_struct *tty = tty_port_tty_get(&port->port); 420 char *ch = (char *)urb->transfer_buffer; 421 int i; 422 423 if (!tty) 424 goto done; 425 426 /* The per character mucking around with sysrq path it too slow for 427 stuff like 3G modems, so shortcircuit it in the 99.9999999% of cases 428 where the USB serial is not a console anyway */ 429 if (!port->console || !port->sysrq) 430 tty_insert_flip_string(tty, ch, urb->actual_length); 431 else { 432 /* Push data to tty */ 433 for (i = 0; i < urb->actual_length; i++, ch++) { 434 if (!usb_serial_handle_sysrq_char(tty, port, *ch)) 435 tty_insert_flip_char(tty, *ch, TTY_NORMAL); 436 } 437 } 438 tty_flip_buffer_push(tty); 439 tty_kref_put(tty); 440 done: 441 usb_serial_generic_resubmit_read_urb(port, GFP_ATOMIC); 442 } 443 444 void usb_serial_generic_read_bulk_callback(struct urb *urb) 445 { 446 struct usb_serial_port *port = urb->context; 447 unsigned char *data = urb->transfer_buffer; 448 int status = urb->status; 449 unsigned long flags; 450 451 dbg("%s - port %d", __func__, port->number); 452 453 if (unlikely(status != 0)) { 454 dbg("%s - nonzero read bulk status received: %d", 455 __func__, status); 456 return; 457 } 458 459 usb_serial_debug_data(debug, &port->dev, __func__, 460 urb->actual_length, data); 461 462 /* Throttle the device if requested by tty */ 463 spin_lock_irqsave(&port->lock, flags); 464 port->throttled = port->throttle_req; 465 if (!port->throttled) { 466 spin_unlock_irqrestore(&port->lock, flags); 467 flush_and_resubmit_read_urb(port); 468 } else 469 spin_unlock_irqrestore(&port->lock, flags); 470 } 471 EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback); 472 473 void usb_serial_generic_write_bulk_callback(struct urb *urb) 474 { 475 unsigned long flags; 476 struct usb_serial_port *port = urb->context; 477 int status = urb->status; 478 479 dbg("%s - port %d", __func__, port->number); 480 481 if (port->serial->type->max_in_flight_urbs) { 482 spin_lock_irqsave(&port->lock, flags); 483 --port->urbs_in_flight; 484 port->tx_bytes_flight -= urb->transfer_buffer_length; 485 if (port->urbs_in_flight < 0) 486 port->urbs_in_flight = 0; 487 spin_unlock_irqrestore(&port->lock, flags); 488 } else { 489 /* Handle the case for single urb mode */ 490 port->write_urb_busy = 0; 491 } 492 493 if (status) { 494 dbg("%s - nonzero write bulk status received: %d", 495 __func__, status); 496 return; 497 } 498 usb_serial_port_softint(port); 499 } 500 EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback); 501 502 void usb_serial_generic_throttle(struct tty_struct *tty) 503 { 504 struct usb_serial_port *port = tty->driver_data; 505 unsigned long flags; 506 507 dbg("%s - port %d", __func__, port->number); 508 509 /* Set the throttle request flag. It will be picked up 510 * by usb_serial_generic_read_bulk_callback(). */ 511 spin_lock_irqsave(&port->lock, flags); 512 port->throttle_req = 1; 513 spin_unlock_irqrestore(&port->lock, flags); 514 } 515 516 void usb_serial_generic_unthrottle(struct tty_struct *tty) 517 { 518 struct usb_serial_port *port = tty->driver_data; 519 int was_throttled; 520 unsigned long flags; 521 522 dbg("%s - port %d", __func__, port->number); 523 524 /* Clear the throttle flags */ 525 spin_lock_irqsave(&port->lock, flags); 526 was_throttled = port->throttled; 527 port->throttled = port->throttle_req = 0; 528 spin_unlock_irqrestore(&port->lock, flags); 529 530 if (was_throttled) { 531 /* Resume reading from device */ 532 usb_serial_generic_resubmit_read_urb(port, GFP_KERNEL); 533 } 534 } 535 536 int usb_serial_handle_sysrq_char(struct tty_struct *tty, 537 struct usb_serial_port *port, unsigned int ch) 538 { 539 if (port->sysrq && port->console) { 540 if (ch && time_before(jiffies, port->sysrq)) { 541 handle_sysrq(ch, tty); 542 port->sysrq = 0; 543 return 1; 544 } 545 port->sysrq = 0; 546 } 547 return 0; 548 } 549 EXPORT_SYMBOL_GPL(usb_serial_handle_sysrq_char); 550 551 int usb_serial_handle_break(struct usb_serial_port *port) 552 { 553 if (!port->sysrq) { 554 port->sysrq = jiffies + HZ*5; 555 return 1; 556 } 557 port->sysrq = 0; 558 return 0; 559 } 560 EXPORT_SYMBOL_GPL(usb_serial_handle_break); 561 562 void usb_serial_generic_disconnect(struct usb_serial *serial) 563 { 564 int i; 565 566 dbg("%s", __func__); 567 568 /* stop reads and writes on all ports */ 569 for (i = 0; i < serial->num_ports; ++i) 570 generic_cleanup(serial->port[i]); 571 } 572 573 void usb_serial_generic_release(struct usb_serial *serial) 574 { 575 dbg("%s", __func__); 576 } 577