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
53static 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
57static const char format_string_manufacturer[] =
58/* S: Manufacturer=xxxx */
59 "S: Manufacturer=%.100s\n";
60
61static const char format_string_product[] =
62/* S: Product=xxxx */
63 "S: Product=%.100s\n";
64
65#ifdef ALLOW_SERIAL_NUMBER
66static const char format_string_serialnumber[] =
67/* S: SerialNumber=xxxx */
68 "S: SerialNumber=%.100s\n";
69#endif
70
71static 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
75static 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
79static const char format_device2[] =
80/* P: Vendor=xxxx ProdID=xxxx Rev=xx.xx */
81 "P: Vendor=%04x ProdID=%04x Rev=%2x.%02x\n";
82
83static 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
87static 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
91static 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
95static 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
99struct class_info {
100 int class;
101 char *class_name;
102};
103
104static const struct class_info clas_info[] = {
105 /* max. 5 chars. per name string */
106 {USB_CLASS_PER_INTERFACE, ">ifc"},
107 {USB_CLASS_AUDIO, .class_name: "audio"},
108 {USB_CLASS_COMM, .class_name: "comm."},
109 {USB_CLASS_HID, .class_name: "HID"},
110 {USB_CLASS_PHYSICAL, .class_name: "PID"},
111 {USB_CLASS_STILL_IMAGE, .class_name: "still"},
112 {USB_CLASS_PRINTER, .class_name: "print"},
113 {USB_CLASS_MASS_STORAGE, .class_name: "stor."},
114 {USB_CLASS_HUB, .class_name: "hub"},
115 {USB_CLASS_CDC_DATA, .class_name: "data"},
116 {USB_CLASS_CSCID, .class_name: "scard"},
117 {USB_CLASS_CONTENT_SEC, .class_name: "c-sec"},
118 {USB_CLASS_VIDEO, .class_name: "video"},
119 {USB_CLASS_PERSONAL_HEALTHCARE, .class_name: "perhc"},
120 {USB_CLASS_AUDIO_VIDEO, .class_name: "av"},
121 {USB_CLASS_BILLBOARD, .class_name: "blbrd"},
122 {USB_CLASS_USB_TYPE_C_BRIDGE, .class_name: "bridg"},
123 {USB_CLASS_WIRELESS_CONTROLLER, .class_name: "wlcon"},
124 {USB_CLASS_MISC, .class_name: "misc"},
125 {USB_CLASS_APP_SPEC, .class_name: "app."},
126 {USB_CLASS_VENDOR_SPEC, .class_name: "vend."},
127 {.class: -1, .class_name: "unk."} /* leave as last */
128};
129
130/*****************************************************************/
131
132static 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
142static 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(epd: desc) ? 'I' : 'O';
152
153 if (speed == USB_SPEED_HIGH)
154 bandwidth = usb_endpoint_maxp_mult(epd: desc);
155
156 /* this isn't checking for illegal values */
157 switch (usb_endpoint_type(epd: 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(epd: desc, speed);
176 if (interval % 1000) {
177 unit = 'u';
178 } else {
179 unit = 'm';
180 interval /= 1000;
181 }
182
183 start += sprintf(buf: start, fmt: format_endpt, desc->bEndpointAddress, dir,
184 desc->bmAttributes, type,
185 usb_endpoint_maxp(epd: desc) *
186 bandwidth,
187 interval, unit);
188 return start;
189}
190
191static 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(buf: start, fmt: format_iface,
210 active ? '*' : ' ', /* mark active altsetting */
211 desc->bInterfaceNumber,
212 desc->bAlternateSetting,
213 desc->bNumEndpoints,
214 desc->bInterfaceClass,
215 class_decode(class: desc->bInterfaceClass),
216 desc->bInterfaceSubClass,
217 desc->bInterfaceProtocol,
218 driver_name);
219 return start;
220}
221
222static 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: &desc->endpoint[i].desc);
233 }
234 return start;
235}
236
237static 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(buf: start, fmt: format_iad,
243 iad->bFirstInterface,
244 iad->bInterfaceCount,
245 iad->bFunctionClass,
246 class_decode(class: 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 */
257static 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(buf: start, fmt: 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
279static 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(buf: start, fmt: "(null Cfg. desc.)\n");
291 start = usb_dump_config_descriptor(start, end, desc: &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 iad: 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, iface: interface, setno: j);
305 }
306 }
307 return start;
308}
309
310/*
311 * Dump the different USB descriptors.
312 */
313static 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(buf: start, fmt: format_device1,
322 bcdUSB >> 8, bcdUSB & 0xff,
323 desc->bDeviceClass,
324 class_decode(class: desc->bDeviceClass),
325 desc->bDeviceSubClass,
326 desc->bDeviceProtocol,
327 desc->bMaxPacketSize0,
328 desc->bNumConfigurations);
329 if (start > end)
330 return start;
331 start += sprintf(buf: start, fmt: 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 */
341static 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(buf: start, fmt: format_string_manufacturer,
348 dev->manufacturer);
349 if (start > end)
350 goto out;
351 if (dev->product)
352 start += sprintf(buf: start, fmt: format_string_product, dev->product);
353 if (start > end)
354 goto out;
355#ifdef ALLOW_SERIAL_NUMBER
356 if (dev->serial)
357 start += sprintf(buf: start, fmt: format_string_serialnumber,
358 dev->serial);
359#endif
360 out:
361 return start;
362}
363
364static 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, desc: &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(speed: dev->speed,
374 start, end, config: dev->config + i,
375 /* active ? */
376 active: (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 */
390static 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_HIGH:
428 speed = "480"; break;
429 case USB_SPEED_SUPER:
430 speed = "5000"; break;
431 case USB_SPEED_SUPER_PLUS:
432 speed = "10000"; break;
433 default:
434 speed = "??";
435 }
436 data_end = pages_start + sprintf(buf: pages_start, fmt: format_topo,
437 bus->busnum, level, parent_devnum,
438 index, count, usbdev->devnum,
439 speed, usbdev->maxchild);
440 /*
441 * level = topology-tier level;
442 * parent_devnum = parent device number;
443 * index = parent's connector number;
444 * count = device count at this level
445 */
446 /* If this is the root hub, display the bandwidth information */
447 if (level == 0) {
448 int max;
449
450 /* super/high speed reserves 80%, full/low reserves 90% */
451 if (usbdev->speed == USB_SPEED_HIGH ||
452 usbdev->speed >= USB_SPEED_SUPER)
453 max = 800;
454 else
455 max = FRAME_TIME_MAX_USECS_ALLOC;
456
457 /* report "average" periodic allocation over a microsecond.
458 * the schedules are actually bursty, HCDs need to deal with
459 * that and just compute/report this average.
460 */
461 data_end += sprintf(buf: data_end, fmt: format_bandwidth,
462 bus->bandwidth_allocated, max,
463 (100 * bus->bandwidth_allocated + max / 2)
464 / max,
465 bus->bandwidth_int_reqs,
466 bus->bandwidth_isoc_reqs);
467
468 }
469 data_end = usb_dump_desc(start: data_end, end: pages_start + (2 * PAGE_SIZE) - 256,
470 dev: usbdev);
471
472 if (data_end > (pages_start + (2 * PAGE_SIZE) - 256))
473 data_end += sprintf(buf: data_end, fmt: "(truncated)\n");
474
475 length = data_end - pages_start;
476 /* if we can start copying some data to the user */
477 if (length > *skip_bytes) {
478 length -= *skip_bytes;
479 if (length > *nbytes)
480 length = *nbytes;
481 if (copy_to_user(to: *buffer, from: pages_start + *skip_bytes, n: length)) {
482 free_pages(addr: (unsigned long)pages_start, order: 1);
483 return -EFAULT;
484 }
485 *nbytes -= length;
486 *file_offset += length;
487 total_written += length;
488 *buffer += length;
489 *skip_bytes = 0;
490 } else
491 *skip_bytes -= length;
492
493 free_pages(addr: (unsigned long)pages_start, order: 1);
494
495 /* Now look at all of this device's children. */
496 usb_hub_for_each_child(usbdev, chix, childdev) {
497 usb_lock_device(childdev);
498 ret = usb_device_dump(buffer, nbytes, skip_bytes,
499 file_offset, usbdev: childdev, bus,
500 level: level + 1, index: chix - 1, count: ++cnt);
501 usb_unlock_device(childdev);
502 if (ret == -EFAULT)
503 return total_written;
504 total_written += ret;
505 }
506 return total_written;
507}
508
509static ssize_t usb_device_read(struct file *file, char __user *buf,
510 size_t nbytes, loff_t *ppos)
511{
512 struct usb_bus *bus;
513 ssize_t ret, total_written = 0;
514 loff_t skip_bytes = *ppos;
515 int id;
516
517 if (*ppos < 0)
518 return -EINVAL;
519 if (nbytes <= 0)
520 return 0;
521
522 mutex_lock(lock: &usb_bus_idr_lock);
523 /* print devices for all busses */
524 idr_for_each_entry(&usb_bus_idr, bus, id) {
525 /* recurse through all children of the root hub */
526 if (!bus_to_hcd(bus)->rh_registered)
527 continue;
528 usb_lock_device(bus->root_hub);
529 ret = usb_device_dump(buffer: &buf, nbytes: &nbytes, skip_bytes: &skip_bytes, file_offset: ppos,
530 usbdev: bus->root_hub, bus, level: 0, index: 0, count: 0);
531 usb_unlock_device(bus->root_hub);
532 if (ret < 0) {
533 mutex_unlock(lock: &usb_bus_idr_lock);
534 return ret;
535 }
536 total_written += ret;
537 }
538 mutex_unlock(lock: &usb_bus_idr_lock);
539 return total_written;
540}
541
542const struct file_operations usbfs_devices_fops = {
543 .llseek = no_seek_end_llseek,
544 .read = usb_device_read,
545};
546