1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * devices.c 4 * (C) Copyright 1999 Randy Dunlap. 5 * (C) Copyright 1999,2000 Thomas Sailer <sailer@ife.ee.ethz.ch>. 6 * (proc file per device) 7 * (C) Copyright 1999 Deti Fliegl (new USB architecture) 8 * 9 ************************************************************* 10 * 11 * <mountpoint>/devices contains USB topology, device, config, class, 12 * interface, & endpoint data. 13 * 14 * I considered using /dev/bus/usb/device# for each device 15 * as it is attached or detached, but I didn't like this for some 16 * reason -- maybe it's just too deep of a directory structure. 17 * I also don't like looking in multiple places to gather and view 18 * the data. Having only one file for ./devices also prevents race 19 * conditions that could arise if a program was reading device info 20 * for devices that are being removed (unplugged). (That is, the 21 * program may find a directory for devnum_12 then try to open it, 22 * but it was just unplugged, so the directory is now deleted. 23 * But programs would just have to be prepared for situations like 24 * this in any plug-and-play environment.) 25 * 26 * 1999-12-16: Thomas Sailer <sailer@ife.ee.ethz.ch> 27 * Converted the whole proc stuff to real 28 * read methods. Now not the whole device list needs to fit 29 * into one page, only the device list for one bus. 30 * Added a poll method to /sys/kernel/debug/usb/devices, to wake 31 * up an eventual usbd 32 * 2000-01-04: Thomas Sailer <sailer@ife.ee.ethz.ch> 33 * Turned into its own filesystem 34 * 2000-07-05: Ashley Montanaro <ashley@compsoc.man.ac.uk> 35 * Converted file reading routine to dump to buffer once 36 * per device, not per bus 37 */ 38 39 #include <linux/fs.h> 40 #include <linux/mm.h> 41 #include <linux/gfp.h> 42 #include <linux/usb.h> 43 #include <linux/usbdevice_fs.h> 44 #include <linux/usb/hcd.h> 45 #include <linux/mutex.h> 46 #include <linux/uaccess.h> 47 48 #include "usb.h" 49 50 /* Define ALLOW_SERIAL_NUMBER if you want to see the serial number of devices */ 51 #define ALLOW_SERIAL_NUMBER 52 53 static const char format_topo[] = 54 /* T: Bus=dd Lev=dd Prnt=dd Port=dd Cnt=dd Dev#=ddd Spd=dddd MxCh=dd */ 55 "\nT: Bus=%2.2d Lev=%2.2d Prnt=%2.2d Port=%2.2d Cnt=%2.2d Dev#=%3d Spd=%-4s MxCh=%2d\n"; 56 57 static const char format_string_manufacturer[] = 58 /* S: Manufacturer=xxxx */ 59 "S: Manufacturer=%.100s\n"; 60 61 static const char format_string_product[] = 62 /* S: Product=xxxx */ 63 "S: Product=%.100s\n"; 64 65 #ifdef ALLOW_SERIAL_NUMBER 66 static const char format_string_serialnumber[] = 67 /* S: SerialNumber=xxxx */ 68 "S: SerialNumber=%.100s\n"; 69 #endif 70 71 static const char format_bandwidth[] = 72 /* B: Alloc=ddd/ddd us (xx%), #Int=ddd, #Iso=ddd */ 73 "B: Alloc=%3d/%3d us (%2d%%), #Int=%3d, #Iso=%3d\n"; 74 75 static const char format_device1[] = 76 /* D: Ver=xx.xx Cls=xx(sssss) Sub=xx Prot=xx MxPS=dd #Cfgs=dd */ 77 "D: Ver=%2x.%02x Cls=%02x(%-5s) Sub=%02x Prot=%02x MxPS=%2d #Cfgs=%3d\n"; 78 79 static const char format_device2[] = 80 /* P: Vendor=xxxx ProdID=xxxx Rev=xx.xx */ 81 "P: Vendor=%04x ProdID=%04x Rev=%2x.%02x\n"; 82 83 static const char format_config[] = 84 /* C: #Ifs=dd Cfg#=dd Atr=xx MPwr=dddmA */ 85 "C:%c #Ifs=%2d Cfg#=%2d Atr=%02x MxPwr=%3dmA\n"; 86 87 static const char format_iad[] = 88 /* A: FirstIf#=dd IfCount=dd Cls=xx(sssss) Sub=xx Prot=xx */ 89 "A: FirstIf#=%2d IfCount=%2d Cls=%02x(%-5s) Sub=%02x Prot=%02x\n"; 90 91 static const char format_iface[] = 92 /* I: If#=dd Alt=dd #EPs=dd Cls=xx(sssss) Sub=xx Prot=xx Driver=xxxx*/ 93 "I:%c If#=%2d Alt=%2d #EPs=%2d Cls=%02x(%-5s) Sub=%02x Prot=%02x Driver=%s\n"; 94 95 static const char format_endpt[] = 96 /* E: Ad=xx(s) Atr=xx(ssss) MxPS=dddd Ivl=D?s */ 97 "E: Ad=%02x(%c) Atr=%02x(%-4s) MxPS=%4d Ivl=%d%cs\n"; 98 99 struct class_info { 100 int class; 101 char *class_name; 102 }; 103 104 static const struct class_info clas_info[] = { 105 /* max. 5 chars. per name string */ 106 {USB_CLASS_PER_INTERFACE, ">ifc"}, 107 {USB_CLASS_AUDIO, "audio"}, 108 {USB_CLASS_COMM, "comm."}, 109 {USB_CLASS_HID, "HID"}, 110 {USB_CLASS_PHYSICAL, "PID"}, 111 {USB_CLASS_STILL_IMAGE, "still"}, 112 {USB_CLASS_PRINTER, "print"}, 113 {USB_CLASS_MASS_STORAGE, "stor."}, 114 {USB_CLASS_HUB, "hub"}, 115 {USB_CLASS_CDC_DATA, "data"}, 116 {USB_CLASS_CSCID, "scard"}, 117 {USB_CLASS_CONTENT_SEC, "c-sec"}, 118 {USB_CLASS_VIDEO, "video"}, 119 {USB_CLASS_PERSONAL_HEALTHCARE, "perhc"}, 120 {USB_CLASS_AUDIO_VIDEO, "av"}, 121 {USB_CLASS_BILLBOARD, "blbrd"}, 122 {USB_CLASS_USB_TYPE_C_BRIDGE, "bridg"}, 123 {USB_CLASS_WIRELESS_CONTROLLER, "wlcon"}, 124 {USB_CLASS_MISC, "misc"}, 125 {USB_CLASS_APP_SPEC, "app."}, 126 {USB_CLASS_VENDOR_SPEC, "vend."}, 127 {-1, "unk."} /* leave as last */ 128 }; 129 130 /*****************************************************************/ 131 132 static const char *class_decode(const int class) 133 { 134 int ix; 135 136 for (ix = 0; clas_info[ix].class != -1; ix++) 137 if (clas_info[ix].class == class) 138 break; 139 return clas_info[ix].class_name; 140 } 141 142 static char *usb_dump_endpoint_descriptor(int speed, char *start, char *end, 143 const struct usb_endpoint_descriptor *desc) 144 { 145 char dir, unit, *type; 146 unsigned interval, bandwidth = 1; 147 148 if (start > end) 149 return start; 150 151 dir = usb_endpoint_dir_in(desc) ? 'I' : 'O'; 152 153 if (speed == USB_SPEED_HIGH) 154 bandwidth = usb_endpoint_maxp_mult(desc); 155 156 /* this isn't checking for illegal values */ 157 switch (usb_endpoint_type(desc)) { 158 case USB_ENDPOINT_XFER_CONTROL: 159 type = "Ctrl"; 160 dir = 'B'; /* ctrl is bidirectional */ 161 break; 162 case USB_ENDPOINT_XFER_ISOC: 163 type = "Isoc"; 164 break; 165 case USB_ENDPOINT_XFER_BULK: 166 type = "Bulk"; 167 break; 168 case USB_ENDPOINT_XFER_INT: 169 type = "Int."; 170 break; 171 default: /* "can't happen" */ 172 return start; 173 } 174 175 interval = usb_decode_interval(desc, speed); 176 if (interval % 1000) { 177 unit = 'u'; 178 } else { 179 unit = 'm'; 180 interval /= 1000; 181 } 182 183 start += sprintf(start, format_endpt, desc->bEndpointAddress, dir, 184 desc->bmAttributes, type, 185 usb_endpoint_maxp(desc) * 186 bandwidth, 187 interval, unit); 188 return start; 189 } 190 191 static char *usb_dump_interface_descriptor(char *start, char *end, 192 const struct usb_interface_cache *intfc, 193 const struct usb_interface *iface, 194 int setno) 195 { 196 const struct usb_interface_descriptor *desc; 197 const char *driver_name = ""; 198 int active = 0; 199 200 if (start > end) 201 return start; 202 desc = &intfc->altsetting[setno].desc; 203 if (iface) { 204 driver_name = (iface->dev.driver 205 ? iface->dev.driver->name 206 : "(none)"); 207 active = (desc == &iface->cur_altsetting->desc); 208 } 209 start += sprintf(start, format_iface, 210 active ? '*' : ' ', /* mark active altsetting */ 211 desc->bInterfaceNumber, 212 desc->bAlternateSetting, 213 desc->bNumEndpoints, 214 desc->bInterfaceClass, 215 class_decode(desc->bInterfaceClass), 216 desc->bInterfaceSubClass, 217 desc->bInterfaceProtocol, 218 driver_name); 219 return start; 220 } 221 222 static char *usb_dump_interface(int speed, char *start, char *end, 223 const struct usb_interface_cache *intfc, 224 const struct usb_interface *iface, int setno) 225 { 226 const struct usb_host_interface *desc = &intfc->altsetting[setno]; 227 int i; 228 229 start = usb_dump_interface_descriptor(start, end, intfc, iface, setno); 230 for (i = 0; i < desc->desc.bNumEndpoints; i++) { 231 start = usb_dump_endpoint_descriptor(speed, 232 start, end, &desc->endpoint[i].desc); 233 } 234 return start; 235 } 236 237 static char *usb_dump_iad_descriptor(char *start, char *end, 238 const struct usb_interface_assoc_descriptor *iad) 239 { 240 if (start > end) 241 return start; 242 start += sprintf(start, format_iad, 243 iad->bFirstInterface, 244 iad->bInterfaceCount, 245 iad->bFunctionClass, 246 class_decode(iad->bFunctionClass), 247 iad->bFunctionSubClass, 248 iad->bFunctionProtocol); 249 return start; 250 } 251 252 /* TBD: 253 * 0. TBDs 254 * 1. marking active interface altsettings (code lists all, but should mark 255 * which ones are active, if any) 256 */ 257 static char *usb_dump_config_descriptor(char *start, char *end, 258 const struct usb_config_descriptor *desc, 259 int active, int speed) 260 { 261 int mul; 262 263 if (start > end) 264 return start; 265 if (speed >= USB_SPEED_SUPER) 266 mul = 8; 267 else 268 mul = 2; 269 start += sprintf(start, format_config, 270 /* mark active/actual/current cfg. */ 271 active ? '*' : ' ', 272 desc->bNumInterfaces, 273 desc->bConfigurationValue, 274 desc->bmAttributes, 275 desc->bMaxPower * mul); 276 return start; 277 } 278 279 static char *usb_dump_config(int speed, char *start, char *end, 280 const struct usb_host_config *config, int active) 281 { 282 int i, j; 283 struct usb_interface_cache *intfc; 284 struct usb_interface *interface; 285 286 if (start > end) 287 return start; 288 if (!config) 289 /* getting these some in 2.3.7; none in 2.3.6 */ 290 return start + sprintf(start, "(null Cfg. desc.)\n"); 291 start = usb_dump_config_descriptor(start, end, &config->desc, active, 292 speed); 293 for (i = 0; i < USB_MAXIADS; i++) { 294 if (config->intf_assoc[i] == NULL) 295 break; 296 start = usb_dump_iad_descriptor(start, end, 297 config->intf_assoc[i]); 298 } 299 for (i = 0; i < config->desc.bNumInterfaces; i++) { 300 intfc = config->intf_cache[i]; 301 interface = config->interface[i]; 302 for (j = 0; j < intfc->num_altsetting; j++) { 303 start = usb_dump_interface(speed, 304 start, end, intfc, interface, j); 305 } 306 } 307 return start; 308 } 309 310 /* 311 * Dump the different USB descriptors. 312 */ 313 static char *usb_dump_device_descriptor(char *start, char *end, 314 const struct usb_device_descriptor *desc) 315 { 316 u16 bcdUSB = le16_to_cpu(desc->bcdUSB); 317 u16 bcdDevice = le16_to_cpu(desc->bcdDevice); 318 319 if (start > end) 320 return start; 321 start += sprintf(start, format_device1, 322 bcdUSB >> 8, bcdUSB & 0xff, 323 desc->bDeviceClass, 324 class_decode(desc->bDeviceClass), 325 desc->bDeviceSubClass, 326 desc->bDeviceProtocol, 327 desc->bMaxPacketSize0, 328 desc->bNumConfigurations); 329 if (start > end) 330 return start; 331 start += sprintf(start, format_device2, 332 le16_to_cpu(desc->idVendor), 333 le16_to_cpu(desc->idProduct), 334 bcdDevice >> 8, bcdDevice & 0xff); 335 return start; 336 } 337 338 /* 339 * Dump the different strings that this device holds. 340 */ 341 static char *usb_dump_device_strings(char *start, char *end, 342 struct usb_device *dev) 343 { 344 if (start > end) 345 return start; 346 if (dev->manufacturer) 347 start += sprintf(start, format_string_manufacturer, 348 dev->manufacturer); 349 if (start > end) 350 goto out; 351 if (dev->product) 352 start += sprintf(start, format_string_product, dev->product); 353 if (start > end) 354 goto out; 355 #ifdef ALLOW_SERIAL_NUMBER 356 if (dev->serial) 357 start += sprintf(start, format_string_serialnumber, 358 dev->serial); 359 #endif 360 out: 361 return start; 362 } 363 364 static char *usb_dump_desc(char *start, char *end, struct usb_device *dev) 365 { 366 int i; 367 368 start = usb_dump_device_descriptor(start, end, &dev->descriptor); 369 370 start = usb_dump_device_strings(start, end, dev); 371 372 for (i = 0; i < dev->descriptor.bNumConfigurations; i++) { 373 start = usb_dump_config(dev->speed, 374 start, end, dev->config + i, 375 /* active ? */ 376 (dev->config + i) == dev->actconfig); 377 } 378 return start; 379 } 380 381 /*****************************************************************/ 382 383 /* This is a recursive function. Parameters: 384 * buffer - the user-space buffer to write data into 385 * nbytes - the maximum number of bytes to write 386 * skip_bytes - the number of bytes to skip before writing anything 387 * file_offset - the offset into the devices file on completion 388 * The caller must own the device lock. 389 */ 390 static ssize_t usb_device_dump(char __user **buffer, size_t *nbytes, 391 loff_t *skip_bytes, loff_t *file_offset, 392 struct usb_device *usbdev, struct usb_bus *bus, 393 int level, int index, int count) 394 { 395 int chix; 396 int ret, cnt = 0; 397 int parent_devnum = 0; 398 char *pages_start, *data_end, *speed; 399 unsigned int length; 400 ssize_t total_written = 0; 401 struct usb_device *childdev = NULL; 402 403 /* don't bother with anything else if we're not writing any data */ 404 if (*nbytes <= 0) 405 return 0; 406 407 if (level > MAX_TOPO_LEVEL) 408 return 0; 409 /* allocate 2^1 pages = 8K (on i386); 410 * should be more than enough for one device */ 411 pages_start = (char *)__get_free_pages(GFP_NOIO, 1); 412 if (!pages_start) 413 return -ENOMEM; 414 415 if (usbdev->parent && usbdev->parent->devnum != -1) 416 parent_devnum = usbdev->parent->devnum; 417 /* 418 * So the root hub's parent is 0 and any device that is 419 * plugged into the root hub has a parent of 0. 420 */ 421 switch (usbdev->speed) { 422 case USB_SPEED_LOW: 423 speed = "1.5"; break; 424 case USB_SPEED_UNKNOWN: /* usb 1.1 root hub code */ 425 case USB_SPEED_FULL: 426 speed = "12"; break; 427 case USB_SPEED_WIRELESS: /* Wireless has no real fixed speed */ 428 case USB_SPEED_HIGH: 429 speed = "480"; break; 430 case USB_SPEED_SUPER: 431 speed = "5000"; break; 432 case USB_SPEED_SUPER_PLUS: 433 speed = "10000"; break; 434 default: 435 speed = "??"; 436 } 437 data_end = pages_start + sprintf(pages_start, format_topo, 438 bus->busnum, level, parent_devnum, 439 index, count, usbdev->devnum, 440 speed, usbdev->maxchild); 441 /* 442 * level = topology-tier level; 443 * parent_devnum = parent device number; 444 * index = parent's connector number; 445 * count = device count at this level 446 */ 447 /* If this is the root hub, display the bandwidth information */ 448 if (level == 0) { 449 int max; 450 451 /* super/high speed reserves 80%, full/low reserves 90% */ 452 if (usbdev->speed == USB_SPEED_HIGH || 453 usbdev->speed >= USB_SPEED_SUPER) 454 max = 800; 455 else 456 max = FRAME_TIME_MAX_USECS_ALLOC; 457 458 /* report "average" periodic allocation over a microsecond. 459 * the schedules are actually bursty, HCDs need to deal with 460 * that and just compute/report this average. 461 */ 462 data_end += sprintf(data_end, format_bandwidth, 463 bus->bandwidth_allocated, max, 464 (100 * bus->bandwidth_allocated + max / 2) 465 / max, 466 bus->bandwidth_int_reqs, 467 bus->bandwidth_isoc_reqs); 468 469 } 470 data_end = usb_dump_desc(data_end, pages_start + (2 * PAGE_SIZE) - 256, 471 usbdev); 472 473 if (data_end > (pages_start + (2 * PAGE_SIZE) - 256)) 474 data_end += sprintf(data_end, "(truncated)\n"); 475 476 length = data_end - pages_start; 477 /* if we can start copying some data to the user */ 478 if (length > *skip_bytes) { 479 length -= *skip_bytes; 480 if (length > *nbytes) 481 length = *nbytes; 482 if (copy_to_user(*buffer, pages_start + *skip_bytes, length)) { 483 free_pages((unsigned long)pages_start, 1); 484 return -EFAULT; 485 } 486 *nbytes -= length; 487 *file_offset += length; 488 total_written += length; 489 *buffer += length; 490 *skip_bytes = 0; 491 } else 492 *skip_bytes -= length; 493 494 free_pages((unsigned long)pages_start, 1); 495 496 /* Now look at all of this device's children. */ 497 usb_hub_for_each_child(usbdev, chix, childdev) { 498 usb_lock_device(childdev); 499 ret = usb_device_dump(buffer, nbytes, skip_bytes, 500 file_offset, childdev, bus, 501 level + 1, chix - 1, ++cnt); 502 usb_unlock_device(childdev); 503 if (ret == -EFAULT) 504 return total_written; 505 total_written += ret; 506 } 507 return total_written; 508 } 509 510 static ssize_t usb_device_read(struct file *file, char __user *buf, 511 size_t nbytes, loff_t *ppos) 512 { 513 struct usb_bus *bus; 514 ssize_t ret, total_written = 0; 515 loff_t skip_bytes = *ppos; 516 int id; 517 518 if (*ppos < 0) 519 return -EINVAL; 520 if (nbytes <= 0) 521 return 0; 522 523 mutex_lock(&usb_bus_idr_lock); 524 /* print devices for all busses */ 525 idr_for_each_entry(&usb_bus_idr, bus, id) { 526 /* recurse through all children of the root hub */ 527 if (!bus_to_hcd(bus)->rh_registered) 528 continue; 529 usb_lock_device(bus->root_hub); 530 ret = usb_device_dump(&buf, &nbytes, &skip_bytes, ppos, 531 bus->root_hub, bus, 0, 0, 0); 532 usb_unlock_device(bus->root_hub); 533 if (ret < 0) { 534 mutex_unlock(&usb_bus_idr_lock); 535 return ret; 536 } 537 total_written += ret; 538 } 539 mutex_unlock(&usb_bus_idr_lock); 540 return total_written; 541 } 542 543 const struct file_operations usbfs_devices_fops = { 544 .llseek = no_seek_end_llseek, 545 .read = usb_device_read, 546 }; 547