1 /* 2 * devices.c 3 * (C) Copyright 1999 Randy Dunlap. 4 * (C) Copyright 1999,2000 Thomas Sailer <sailer@ife.ee.ethz.ch>. (proc file per device) 5 * (C) Copyright 1999 Deti Fliegl (new USB architecture) 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License as published by 9 * the Free Software Foundation; either version 2 of the License, or 10 * (at your option) any later version. 11 * 12 * This program is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with this program; if not, write to the Free Software 19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 20 * 21 ************************************************************* 22 * 23 * <mountpoint>/devices contains USB topology, device, config, class, 24 * interface, & endpoint data. 25 * 26 * I considered using /proc/bus/usb/devices/device# for each device 27 * as it is attached or detached, but I didn't like this for some 28 * reason -- maybe it's just too deep of a directory structure. 29 * I also don't like looking in multiple places to gather and view 30 * the data. Having only one file for ./devices also prevents race 31 * conditions that could arise if a program was reading device info 32 * for devices that are being removed (unplugged). (That is, the 33 * program may find a directory for devnum_12 then try to open it, 34 * but it was just unplugged, so the directory is now deleted. 35 * But programs would just have to be prepared for situations like 36 * this in any plug-and-play environment.) 37 * 38 * 1999-12-16: Thomas Sailer <sailer@ife.ee.ethz.ch> 39 * Converted the whole proc stuff to real 40 * read methods. Now not the whole device list needs to fit 41 * into one page, only the device list for one bus. 42 * Added a poll method to /proc/bus/usb/devices, to wake 43 * up an eventual usbd 44 * 2000-01-04: Thomas Sailer <sailer@ife.ee.ethz.ch> 45 * Turned into its own filesystem 46 * 2000-07-05: Ashley Montanaro <ashley@compsoc.man.ac.uk> 47 * Converted file reading routine to dump to buffer once 48 * per device, not per bus 49 */ 50 51 #include <linux/fs.h> 52 #include <linux/mm.h> 53 #include <linux/slab.h> 54 #include <linux/poll.h> 55 #include <linux/usb.h> 56 #include <linux/smp_lock.h> 57 #include <linux/usbdevice_fs.h> 58 #include <linux/mutex.h> 59 #include <asm/uaccess.h> 60 61 #include "usb.h" 62 #include "hcd.h" 63 64 /* Define ALLOW_SERIAL_NUMBER if you want to see the serial number of devices */ 65 #define ALLOW_SERIAL_NUMBER 66 67 static const char *format_topo = 68 /* T: Bus=dd Lev=dd Prnt=dd Port=dd Cnt=dd Dev#=ddd Spd=ddd MxCh=dd */ 69 "\nT: Bus=%2.2d Lev=%2.2d Prnt=%2.2d Port=%2.2d Cnt=%2.2d Dev#=%3d Spd=%3s MxCh=%2d\n"; 70 71 static const char *format_string_manufacturer = 72 /* S: Manufacturer=xxxx */ 73 "S: Manufacturer=%.100s\n"; 74 75 static const char *format_string_product = 76 /* S: Product=xxxx */ 77 "S: Product=%.100s\n"; 78 79 #ifdef ALLOW_SERIAL_NUMBER 80 static const char *format_string_serialnumber = 81 /* S: SerialNumber=xxxx */ 82 "S: SerialNumber=%.100s\n"; 83 #endif 84 85 static const char *format_bandwidth = 86 /* B: Alloc=ddd/ddd us (xx%), #Int=ddd, #Iso=ddd */ 87 "B: Alloc=%3d/%3d us (%2d%%), #Int=%3d, #Iso=%3d\n"; 88 89 static const char *format_device1 = 90 /* D: Ver=xx.xx Cls=xx(sssss) Sub=xx Prot=xx MxPS=dd #Cfgs=dd */ 91 "D: Ver=%2x.%02x Cls=%02x(%-5s) Sub=%02x Prot=%02x MxPS=%2d #Cfgs=%3d\n"; 92 93 static const char *format_device2 = 94 /* P: Vendor=xxxx ProdID=xxxx Rev=xx.xx */ 95 "P: Vendor=%04x ProdID=%04x Rev=%2x.%02x\n"; 96 97 static const char *format_config = 98 /* C: #Ifs=dd Cfg#=dd Atr=xx MPwr=dddmA */ 99 "C:%c #Ifs=%2d Cfg#=%2d Atr=%02x MxPwr=%3dmA\n"; 100 101 static const char *format_iad = 102 /* A: FirstIf#=dd IfCount=dd Cls=xx(sssss) Sub=xx Prot=xx */ 103 "A: FirstIf#=%2d IfCount=%2d Cls=%02x(%-5s) Sub=%02x Prot=%02x\n"; 104 105 static const char *format_iface = 106 /* I: If#=dd Alt=dd #EPs=dd Cls=xx(sssss) Sub=xx Prot=xx Driver=xxxx*/ 107 "I:%c If#=%2d Alt=%2d #EPs=%2d Cls=%02x(%-5s) Sub=%02x Prot=%02x Driver=%s\n"; 108 109 static const char *format_endpt = 110 /* E: Ad=xx(s) Atr=xx(ssss) MxPS=dddd Ivl=D?s */ 111 "E: Ad=%02x(%c) Atr=%02x(%-4s) MxPS=%4d Ivl=%d%cs\n"; 112 113 114 /* 115 * Need access to the driver and USB bus lists. 116 * extern struct list_head usb_bus_list; 117 * However, these will come from functions that return ptrs to each of them. 118 */ 119 120 static DECLARE_WAIT_QUEUE_HEAD(deviceconndiscwq); 121 static unsigned int conndiscevcnt; 122 123 /* this struct stores the poll state for <mountpoint>/devices pollers */ 124 struct usb_device_status { 125 unsigned int lastev; 126 }; 127 128 struct class_info { 129 int class; 130 char *class_name; 131 }; 132 133 static const struct class_info clas_info[] = 134 { /* max. 5 chars. per name string */ 135 {USB_CLASS_PER_INTERFACE, ">ifc"}, 136 {USB_CLASS_AUDIO, "audio"}, 137 {USB_CLASS_COMM, "comm."}, 138 {USB_CLASS_HID, "HID"}, 139 {USB_CLASS_PHYSICAL, "PID"}, 140 {USB_CLASS_STILL_IMAGE, "still"}, 141 {USB_CLASS_PRINTER, "print"}, 142 {USB_CLASS_MASS_STORAGE, "stor."}, 143 {USB_CLASS_HUB, "hub"}, 144 {USB_CLASS_CDC_DATA, "data"}, 145 {USB_CLASS_CSCID, "scard"}, 146 {USB_CLASS_CONTENT_SEC, "c-sec"}, 147 {USB_CLASS_VIDEO, "video"}, 148 {USB_CLASS_WIRELESS_CONTROLLER, "wlcon"}, 149 {USB_CLASS_MISC, "misc"}, 150 {USB_CLASS_APP_SPEC, "app."}, 151 {USB_CLASS_VENDOR_SPEC, "vend."}, 152 {-1, "unk."} /* leave as last */ 153 }; 154 155 /*****************************************************************/ 156 157 void usbfs_conn_disc_event(void) 158 { 159 conndiscevcnt++; 160 wake_up(&deviceconndiscwq); 161 } 162 163 static const char *class_decode(const int class) 164 { 165 int ix; 166 167 for (ix = 0; clas_info[ix].class != -1; ix++) 168 if (clas_info[ix].class == class) 169 break; 170 return clas_info[ix].class_name; 171 } 172 173 static char *usb_dump_endpoint_descriptor(int speed, char *start, char *end, 174 const struct usb_endpoint_descriptor *desc) 175 { 176 char dir, unit, *type; 177 unsigned interval, bandwidth = 1; 178 179 if (start > end) 180 return start; 181 182 dir = usb_endpoint_dir_in(desc) ? 'I' : 'O'; 183 184 if (speed == USB_SPEED_HIGH) { 185 switch (le16_to_cpu(desc->wMaxPacketSize) & (0x03 << 11)) { 186 case 1 << 11: bandwidth = 2; break; 187 case 2 << 11: bandwidth = 3; break; 188 } 189 } 190 191 /* this isn't checking for illegal values */ 192 switch (usb_endpoint_type(desc)) { 193 case USB_ENDPOINT_XFER_CONTROL: 194 type = "Ctrl"; 195 if (speed == USB_SPEED_HIGH) /* uframes per NAK */ 196 interval = desc->bInterval; 197 else 198 interval = 0; 199 dir = 'B'; /* ctrl is bidirectional */ 200 break; 201 case USB_ENDPOINT_XFER_ISOC: 202 type = "Isoc"; 203 interval = 1 << (desc->bInterval - 1); 204 break; 205 case USB_ENDPOINT_XFER_BULK: 206 type = "Bulk"; 207 if (speed == USB_SPEED_HIGH && dir == 'O') /* uframes per NAK */ 208 interval = desc->bInterval; 209 else 210 interval = 0; 211 break; 212 case USB_ENDPOINT_XFER_INT: 213 type = "Int."; 214 if (speed == USB_SPEED_HIGH) 215 interval = 1 << (desc->bInterval - 1); 216 else 217 interval = desc->bInterval; 218 break; 219 default: /* "can't happen" */ 220 return start; 221 } 222 interval *= (speed == USB_SPEED_HIGH) ? 125 : 1000; 223 if (interval % 1000) 224 unit = 'u'; 225 else { 226 unit = 'm'; 227 interval /= 1000; 228 } 229 230 start += sprintf(start, format_endpt, desc->bEndpointAddress, dir, 231 desc->bmAttributes, type, 232 (le16_to_cpu(desc->wMaxPacketSize) & 0x07ff) * 233 bandwidth, 234 interval, unit); 235 return start; 236 } 237 238 static char *usb_dump_interface_descriptor(char *start, char *end, 239 const struct usb_interface_cache *intfc, 240 const struct usb_interface *iface, 241 int setno) 242 { 243 const struct usb_interface_descriptor *desc; 244 const char *driver_name = ""; 245 int active = 0; 246 247 if (start > end) 248 return start; 249 desc = &intfc->altsetting[setno].desc; 250 if (iface) { 251 driver_name = (iface->dev.driver 252 ? iface->dev.driver->name 253 : "(none)"); 254 active = (desc == &iface->cur_altsetting->desc); 255 } 256 start += sprintf(start, format_iface, 257 active ? '*' : ' ', /* mark active altsetting */ 258 desc->bInterfaceNumber, 259 desc->bAlternateSetting, 260 desc->bNumEndpoints, 261 desc->bInterfaceClass, 262 class_decode(desc->bInterfaceClass), 263 desc->bInterfaceSubClass, 264 desc->bInterfaceProtocol, 265 driver_name); 266 return start; 267 } 268 269 static char *usb_dump_interface(int speed, char *start, char *end, 270 const struct usb_interface_cache *intfc, 271 const struct usb_interface *iface, int setno) 272 { 273 const struct usb_host_interface *desc = &intfc->altsetting[setno]; 274 int i; 275 276 start = usb_dump_interface_descriptor(start, end, intfc, iface, setno); 277 for (i = 0; i < desc->desc.bNumEndpoints; i++) { 278 if (start > end) 279 return start; 280 start = usb_dump_endpoint_descriptor(speed, 281 start, end, &desc->endpoint[i].desc); 282 } 283 return start; 284 } 285 286 static char *usb_dump_iad_descriptor(char *start, char *end, 287 const struct usb_interface_assoc_descriptor *iad) 288 { 289 if (start > end) 290 return start; 291 start += sprintf(start, format_iad, 292 iad->bFirstInterface, 293 iad->bInterfaceCount, 294 iad->bFunctionClass, 295 class_decode(iad->bFunctionClass), 296 iad->bFunctionSubClass, 297 iad->bFunctionProtocol); 298 return start; 299 } 300 301 /* TBD: 302 * 0. TBDs 303 * 1. marking active interface altsettings (code lists all, but should mark 304 * which ones are active, if any) 305 */ 306 static char *usb_dump_config_descriptor(char *start, char *end, 307 const struct usb_config_descriptor *desc, 308 int active) 309 { 310 if (start > end) 311 return start; 312 start += sprintf(start, format_config, 313 /* mark active/actual/current cfg. */ 314 active ? '*' : ' ', 315 desc->bNumInterfaces, 316 desc->bConfigurationValue, 317 desc->bmAttributes, 318 desc->bMaxPower * 2); 319 return start; 320 } 321 322 static char *usb_dump_config(int speed, char *start, char *end, 323 const struct usb_host_config *config, int active) 324 { 325 int i, j; 326 struct usb_interface_cache *intfc; 327 struct usb_interface *interface; 328 329 if (start > end) 330 return start; 331 if (!config) 332 /* getting these some in 2.3.7; none in 2.3.6 */ 333 return start + sprintf(start, "(null Cfg. desc.)\n"); 334 start = usb_dump_config_descriptor(start, end, &config->desc, active); 335 for (i = 0; i < USB_MAXIADS; i++) { 336 if (config->intf_assoc[i] == NULL) 337 break; 338 start = usb_dump_iad_descriptor(start, end, 339 config->intf_assoc[i]); 340 } 341 for (i = 0; i < config->desc.bNumInterfaces; i++) { 342 intfc = config->intf_cache[i]; 343 interface = config->interface[i]; 344 for (j = 0; j < intfc->num_altsetting; j++) { 345 if (start > end) 346 return start; 347 start = usb_dump_interface(speed, 348 start, end, intfc, interface, j); 349 } 350 } 351 return start; 352 } 353 354 /* 355 * Dump the different USB descriptors. 356 */ 357 static char *usb_dump_device_descriptor(char *start, char *end, 358 const struct usb_device_descriptor *desc) 359 { 360 u16 bcdUSB = le16_to_cpu(desc->bcdUSB); 361 u16 bcdDevice = le16_to_cpu(desc->bcdDevice); 362 363 if (start > end) 364 return start; 365 start += sprintf(start, format_device1, 366 bcdUSB >> 8, bcdUSB & 0xff, 367 desc->bDeviceClass, 368 class_decode(desc->bDeviceClass), 369 desc->bDeviceSubClass, 370 desc->bDeviceProtocol, 371 desc->bMaxPacketSize0, 372 desc->bNumConfigurations); 373 if (start > end) 374 return start; 375 start += sprintf(start, format_device2, 376 le16_to_cpu(desc->idVendor), 377 le16_to_cpu(desc->idProduct), 378 bcdDevice >> 8, bcdDevice & 0xff); 379 return start; 380 } 381 382 /* 383 * Dump the different strings that this device holds. 384 */ 385 static char *usb_dump_device_strings(char *start, char *end, 386 struct usb_device *dev) 387 { 388 if (start > end) 389 return start; 390 if (dev->manufacturer) 391 start += sprintf(start, format_string_manufacturer, 392 dev->manufacturer); 393 if (start > end) 394 goto out; 395 if (dev->product) 396 start += sprintf(start, format_string_product, dev->product); 397 if (start > end) 398 goto out; 399 #ifdef ALLOW_SERIAL_NUMBER 400 if (dev->serial) 401 start += sprintf(start, format_string_serialnumber, 402 dev->serial); 403 #endif 404 out: 405 return start; 406 } 407 408 static char *usb_dump_desc(char *start, char *end, struct usb_device *dev) 409 { 410 int i; 411 412 if (start > end) 413 return start; 414 415 start = usb_dump_device_descriptor(start, end, &dev->descriptor); 416 417 if (start > end) 418 return start; 419 420 start = usb_dump_device_strings(start, end, dev); 421 422 for (i = 0; i < dev->descriptor.bNumConfigurations; i++) { 423 if (start > end) 424 return start; 425 start = usb_dump_config(dev->speed, 426 start, end, dev->config + i, 427 /* active ? */ 428 (dev->config + i) == dev->actconfig); 429 } 430 return start; 431 } 432 433 434 #ifdef PROC_EXTRA /* TBD: may want to add this code later */ 435 436 static char *usb_dump_hub_descriptor(char *start, char *end, 437 const struct usb_hub_descriptor *desc) 438 { 439 int leng = USB_DT_HUB_NONVAR_SIZE; 440 unsigned char *ptr = (unsigned char *)desc; 441 442 if (start > end) 443 return start; 444 start += sprintf(start, "Interface:"); 445 while (leng && start <= end) { 446 start += sprintf(start, " %02x", *ptr); 447 ptr++; leng--; 448 } 449 *start++ = '\n'; 450 return start; 451 } 452 453 static char *usb_dump_string(char *start, char *end, 454 const struct usb_device *dev, char *id, int index) 455 { 456 if (start > end) 457 return start; 458 start += sprintf(start, "Interface:"); 459 if (index <= dev->maxstring && dev->stringindex && 460 dev->stringindex[index]) 461 start += sprintf(start, "%s: %.100s ", id, 462 dev->stringindex[index]); 463 return start; 464 } 465 466 #endif /* PROC_EXTRA */ 467 468 /*****************************************************************/ 469 470 /* This is a recursive function. Parameters: 471 * buffer - the user-space buffer to write data into 472 * nbytes - the maximum number of bytes to write 473 * skip_bytes - the number of bytes to skip before writing anything 474 * file_offset - the offset into the devices file on completion 475 * The caller must own the device lock. 476 */ 477 static ssize_t usb_device_dump(char __user **buffer, size_t *nbytes, 478 loff_t *skip_bytes, loff_t *file_offset, 479 struct usb_device *usbdev, struct usb_bus *bus, 480 int level, int index, int count) 481 { 482 int chix; 483 int ret, cnt = 0; 484 int parent_devnum = 0; 485 char *pages_start, *data_end, *speed; 486 unsigned int length; 487 ssize_t total_written = 0; 488 489 /* don't bother with anything else if we're not writing any data */ 490 if (*nbytes <= 0) 491 return 0; 492 493 if (level > MAX_TOPO_LEVEL) 494 return 0; 495 /* allocate 2^1 pages = 8K (on i386); 496 * should be more than enough for one device */ 497 pages_start = (char *)__get_free_pages(GFP_KERNEL, 1); 498 if (!pages_start) 499 return -ENOMEM; 500 501 if (usbdev->parent && usbdev->parent->devnum != -1) 502 parent_devnum = usbdev->parent->devnum; 503 /* 504 * So the root hub's parent is 0 and any device that is 505 * plugged into the root hub has a parent of 0. 506 */ 507 switch (usbdev->speed) { 508 case USB_SPEED_LOW: 509 speed = "1.5"; break; 510 case USB_SPEED_UNKNOWN: /* usb 1.1 root hub code */ 511 case USB_SPEED_FULL: 512 speed = "12 "; break; 513 case USB_SPEED_HIGH: 514 speed = "480"; break; 515 default: 516 speed = "?? "; 517 } 518 data_end = pages_start + sprintf(pages_start, format_topo, 519 bus->busnum, level, parent_devnum, 520 index, count, usbdev->devnum, 521 speed, usbdev->maxchild); 522 /* 523 * level = topology-tier level; 524 * parent_devnum = parent device number; 525 * index = parent's connector number; 526 * count = device count at this level 527 */ 528 /* If this is the root hub, display the bandwidth information */ 529 if (level == 0) { 530 int max; 531 532 /* high speed reserves 80%, full/low reserves 90% */ 533 if (usbdev->speed == USB_SPEED_HIGH) 534 max = 800; 535 else 536 max = FRAME_TIME_MAX_USECS_ALLOC; 537 538 /* report "average" periodic allocation over a microsecond. 539 * the schedules are actually bursty, HCDs need to deal with 540 * that and just compute/report this average. 541 */ 542 data_end += sprintf(data_end, format_bandwidth, 543 bus->bandwidth_allocated, max, 544 (100 * bus->bandwidth_allocated + max / 2) 545 / max, 546 bus->bandwidth_int_reqs, 547 bus->bandwidth_isoc_reqs); 548 549 } 550 data_end = usb_dump_desc(data_end, pages_start + (2 * PAGE_SIZE) - 256, 551 usbdev); 552 553 if (data_end > (pages_start + (2 * PAGE_SIZE) - 256)) 554 data_end += sprintf(data_end, "(truncated)\n"); 555 556 length = data_end - pages_start; 557 /* if we can start copying some data to the user */ 558 if (length > *skip_bytes) { 559 length -= *skip_bytes; 560 if (length > *nbytes) 561 length = *nbytes; 562 if (copy_to_user(*buffer, pages_start + *skip_bytes, length)) { 563 free_pages((unsigned long)pages_start, 1); 564 return -EFAULT; 565 } 566 *nbytes -= length; 567 *file_offset += length; 568 total_written += length; 569 *buffer += length; 570 *skip_bytes = 0; 571 } else 572 *skip_bytes -= length; 573 574 free_pages((unsigned long)pages_start, 1); 575 576 /* Now look at all of this device's children. */ 577 for (chix = 0; chix < usbdev->maxchild; chix++) { 578 struct usb_device *childdev = usbdev->children[chix]; 579 580 if (childdev) { 581 usb_lock_device(childdev); 582 ret = usb_device_dump(buffer, nbytes, skip_bytes, 583 file_offset, childdev, bus, 584 level + 1, chix, ++cnt); 585 usb_unlock_device(childdev); 586 if (ret == -EFAULT) 587 return total_written; 588 total_written += ret; 589 } 590 } 591 return total_written; 592 } 593 594 static ssize_t usb_device_read(struct file *file, char __user *buf, 595 size_t nbytes, loff_t *ppos) 596 { 597 struct usb_bus *bus; 598 ssize_t ret, total_written = 0; 599 loff_t skip_bytes = *ppos; 600 601 if (*ppos < 0) 602 return -EINVAL; 603 if (nbytes <= 0) 604 return 0; 605 if (!access_ok(VERIFY_WRITE, buf, nbytes)) 606 return -EFAULT; 607 608 mutex_lock(&usb_bus_list_lock); 609 /* print devices for all busses */ 610 list_for_each_entry(bus, &usb_bus_list, bus_list) { 611 /* recurse through all children of the root hub */ 612 if (!bus->root_hub) 613 continue; 614 usb_lock_device(bus->root_hub); 615 ret = usb_device_dump(&buf, &nbytes, &skip_bytes, ppos, 616 bus->root_hub, bus, 0, 0, 0); 617 usb_unlock_device(bus->root_hub); 618 if (ret < 0) { 619 mutex_unlock(&usb_bus_list_lock); 620 return ret; 621 } 622 total_written += ret; 623 } 624 mutex_unlock(&usb_bus_list_lock); 625 return total_written; 626 } 627 628 /* Kernel lock for "lastev" protection */ 629 static unsigned int usb_device_poll(struct file *file, 630 struct poll_table_struct *wait) 631 { 632 struct usb_device_status *st = file->private_data; 633 unsigned int mask = 0; 634 635 lock_kernel(); 636 if (!st) { 637 st = kmalloc(sizeof(struct usb_device_status), GFP_KERNEL); 638 639 /* we may have dropped BKL - 640 * need to check for having lost the race */ 641 if (file->private_data) { 642 kfree(st); 643 st = file->private_data; 644 goto lost_race; 645 } 646 /* we haven't lost - check for allocation failure now */ 647 if (!st) { 648 unlock_kernel(); 649 return POLLIN; 650 } 651 652 /* 653 * need to prevent the module from being unloaded, since 654 * proc_unregister does not call the release method and 655 * we would have a memory leak 656 */ 657 st->lastev = conndiscevcnt; 658 file->private_data = st; 659 mask = POLLIN; 660 } 661 lost_race: 662 if (file->f_mode & FMODE_READ) 663 poll_wait(file, &deviceconndiscwq, wait); 664 if (st->lastev != conndiscevcnt) 665 mask |= POLLIN; 666 st->lastev = conndiscevcnt; 667 unlock_kernel(); 668 return mask; 669 } 670 671 static int usb_device_open(struct inode *inode, struct file *file) 672 { 673 file->private_data = NULL; 674 return 0; 675 } 676 677 static int usb_device_release(struct inode *inode, struct file *file) 678 { 679 kfree(file->private_data); 680 file->private_data = NULL; 681 return 0; 682 } 683 684 static loff_t usb_device_lseek(struct file *file, loff_t offset, int orig) 685 { 686 loff_t ret; 687 688 lock_kernel(); 689 690 switch (orig) { 691 case 0: 692 file->f_pos = offset; 693 ret = file->f_pos; 694 break; 695 case 1: 696 file->f_pos += offset; 697 ret = file->f_pos; 698 break; 699 case 2: 700 default: 701 ret = -EINVAL; 702 } 703 704 unlock_kernel(); 705 return ret; 706 } 707 708 const struct file_operations usbfs_devices_fops = { 709 .llseek = usb_device_lseek, 710 .read = usb_device_read, 711 .poll = usb_device_poll, 712 .open = usb_device_open, 713 .release = usb_device_release, 714 }; 715