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1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * devices.c
4 * (C) Copyright 1999 Randy Dunlap.
5 * (C) Copyright 1999,2000 Thomas Sailer <[email protected]>.
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 <[email protected]>
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 <[email protected]>
33 * Turned into its own filesystem
34 * 2000-07-05: Ashley Montanaro <[email protected]>
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/slab.h>
41#include <linux/mm.h>
42#include <linux/gfp.h>
43#include <linux/usb.h>
44#include <linux/usbdevice_fs.h>
45#include <linux/usb/hcd.h>
46#include <linux/mutex.h>
47#include <linux/uaccess.h>
48
49#include "usb.h"
50
51/* Define ALLOW_SERIAL_NUMBER if you want to see the serial number of devices */
52#define ALLOW_SERIAL_NUMBER
53
54static const char format_topo[] =
55/* T: Bus=dd Lev=dd Prnt=dd Port=dd Cnt=dd Dev#=ddd Spd=dddd MxCh=dd */
56"\nT: Bus=%2.2d Lev=%2.2d Prnt=%2.2d Port=%2.2d Cnt=%2.2d Dev#=%3d Spd=%-4s MxCh=%2d\n";
57
58static const char format_string_manufacturer[] =
59/* S: Manufacturer=xxxx */
60 "S: Manufacturer=%.100s\n";
61
62static const char format_string_product[] =
63/* S: Product=xxxx */
64 "S: Product=%.100s\n";
65
66#ifdef ALLOW_SERIAL_NUMBER
67static const char format_string_serialnumber[] =
68/* S: SerialNumber=xxxx */
69 "S: SerialNumber=%.100s\n";
70#endif
71
72static const char format_bandwidth[] =
73/* B: Alloc=ddd/ddd us (xx%), #Int=ddd, #Iso=ddd */
74 "B: Alloc=%3d/%3d us (%2d%%), #Int=%3d, #Iso=%3d\n";
75
76static const char format_device1[] =
77/* D: Ver=xx.xx Cls=xx(sssss) Sub=xx Prot=xx MxPS=dd #Cfgs=dd */
78 "D: Ver=%2x.%02x Cls=%02x(%-5s) Sub=%02x Prot=%02x MxPS=%2d #Cfgs=%3d\n";
79
80static const char format_device2[] =
81/* P: Vendor=xxxx ProdID=xxxx Rev=xx.xx */
82 "P: Vendor=%04x ProdID=%04x Rev=%2x.%02x\n";
83
84static const char format_config[] =
85/* C: #Ifs=dd Cfg#=dd Atr=xx MPwr=dddmA */
86 "C:%c #Ifs=%2d Cfg#=%2d Atr=%02x MxPwr=%3dmA\n";
87
88static const char format_iad[] =
89/* A: FirstIf#=dd IfCount=dd Cls=xx(sssss) Sub=xx Prot=xx */
90 "A: FirstIf#=%2d IfCount=%2d Cls=%02x(%-5s) Sub=%02x Prot=%02x\n";
91
92static const char format_iface[] =
93/* I: If#=dd Alt=dd #EPs=dd Cls=xx(sssss) Sub=xx Prot=xx Driver=xxxx*/
94 "I:%c If#=%2d Alt=%2d #EPs=%2d Cls=%02x(%-5s) Sub=%02x Prot=%02x Driver=%s\n";
95
96static const char format_endpt[] =
97/* E: Ad=xx(s) Atr=xx(ssss) MxPS=dddd Ivl=D?s */
98 "E: Ad=%02x(%c) Atr=%02x(%-4s) MxPS=%4d Ivl=%d%cs\n";
99
100struct class_info {
101 int class;
102 char *class_name;
103};
104
105static const struct class_info clas_info[] = {
106 /* max. 5 chars. per name string */
107 {USB_CLASS_PER_INTERFACE, ">ifc"},
108 {USB_CLASS_AUDIO, "audio"},
109 {USB_CLASS_COMM, "comm."},
110 {USB_CLASS_HID, "HID"},
111 {USB_CLASS_PHYSICAL, "PID"},
112 {USB_CLASS_STILL_IMAGE, "still"},
113 {USB_CLASS_PRINTER, "print"},
114 {USB_CLASS_MASS_STORAGE, "stor."},
115 {USB_CLASS_HUB, "hub"},
116 {USB_CLASS_CDC_DATA, "data"},
117 {USB_CLASS_CSCID, "scard"},
118 {USB_CLASS_CONTENT_SEC, "c-sec"},
119 {USB_CLASS_VIDEO, "video"},
120 {USB_CLASS_PERSONAL_HEALTHCARE, "perhc"},
121 {USB_CLASS_AUDIO_VIDEO, "av"},
122 {USB_CLASS_BILLBOARD, "blbrd"},
123 {USB_CLASS_USB_TYPE_C_BRIDGE, "bridg"},
124 {USB_CLASS_WIRELESS_CONTROLLER, "wlcon"},
125 {USB_CLASS_MISC, "misc"},
126 {USB_CLASS_APP_SPEC, "app."},
127 {USB_CLASS_VENDOR_SPEC, "vend."},
128 {-1, "unk."} /* leave as last */
129};
130
131/*****************************************************************/
132
133static const char *class_decode(const int class)
134{
135 int ix;
136
137 for (ix = 0; clas_info[ix].class != -1; ix++)
138 if (clas_info[ix].class == class)
139 break;
140 return clas_info[ix].class_name;
141}
142
143static char *usb_dump_endpoint_descriptor(int speed, char *start, char *end,
144 const struct usb_endpoint_descriptor *desc)
145{
146 char dir, unit, *type;
147 unsigned interval, bandwidth = 1;
148
149 if (start > end)
150 return start;
151
152 dir = usb_endpoint_dir_in(desc) ? 'I' : 'O';
153
154 if (speed == USB_SPEED_HIGH)
155 bandwidth = usb_endpoint_maxp_mult(desc);
156
157 /* this isn't checking for illegal values */
158 switch (usb_endpoint_type(desc)) {
159 case USB_ENDPOINT_XFER_CONTROL:
160 type = "Ctrl";
161 dir = 'B'; /* ctrl is bidirectional */
162 break;
163 case USB_ENDPOINT_XFER_ISOC:
164 type = "Isoc";
165 break;
166 case USB_ENDPOINT_XFER_BULK:
167 type = "Bulk";
168 break;
169 case USB_ENDPOINT_XFER_INT:
170 type = "Int.";
171 break;
172 default: /* "can't happen" */
173 return start;
174 }
175
176 interval = usb_decode_interval(desc, speed);
177 if (interval % 1000) {
178 unit = 'u';
179 } else {
180 unit = 'm';
181 interval /= 1000;
182 }
183
184 start += sprintf(start, format_endpt, desc->bEndpointAddress, dir,
185 desc->bmAttributes, type,
186 usb_endpoint_maxp(desc) *
187 bandwidth,
188 interval, unit);
189 return start;
190}
191
192static char *usb_dump_interface_descriptor(char *start, char *end,
193 const struct usb_interface_cache *intfc,
194 const struct usb_interface *iface,
195 int setno)
196{
197 const struct usb_interface_descriptor *desc;
198 const char *driver_name = "";
199 int active = 0;
200
201 if (start > end)
202 return start;
203 desc = &intfc->altsetting[setno].desc;
204 if (iface) {
205 driver_name = (iface->dev.driver
206 ? iface->dev.driver->name
207 : "(none)");
208 active = (desc == &iface->cur_altsetting->desc);
209 }
210 start += sprintf(start, format_iface,
211 active ? '*' : ' ', /* mark active altsetting */
212 desc->bInterfaceNumber,
213 desc->bAlternateSetting,
214 desc->bNumEndpoints,
215 desc->bInterfaceClass,
216 class_decode(desc->bInterfaceClass),
217 desc->bInterfaceSubClass,
218 desc->bInterfaceProtocol,
219 driver_name);
220 return start;
221}
222
223static char *usb_dump_interface(int speed, char *start, char *end,
224 const struct usb_interface_cache *intfc,
225 const struct usb_interface *iface, int setno)
226{
227 const struct usb_host_interface *desc = &intfc->altsetting[setno];
228 int i;
229
230 start = usb_dump_interface_descriptor(start, end, intfc, iface, setno);
231 for (i = 0; i < desc->desc.bNumEndpoints; i++) {
232 start = usb_dump_endpoint_descriptor(speed,
233 start, end, &desc->endpoint[i].desc);
234 }
235 return start;
236}
237
238static char *usb_dump_iad_descriptor(char *start, char *end,
239 const struct usb_interface_assoc_descriptor *iad)
240{
241 if (start > end)
242 return start;
243 start += sprintf(start, format_iad,
244 iad->bFirstInterface,
245 iad->bInterfaceCount,
246 iad->bFunctionClass,
247 class_decode(iad->bFunctionClass),
248 iad->bFunctionSubClass,
249 iad->bFunctionProtocol);
250 return start;
251}
252
253/* TBD:
254 * 0. TBDs
255 * 1. marking active interface altsettings (code lists all, but should mark
256 * which ones are active, if any)
257 */
258static char *usb_dump_config_descriptor(char *start, char *end,
259 const struct usb_config_descriptor *desc,
260 int active, int speed)
261{
262 int mul;
263
264 if (start > end)
265 return start;
266 if (speed >= USB_SPEED_SUPER)
267 mul = 8;
268 else
269 mul = 2;
270 start += sprintf(start, format_config,
271 /* mark active/actual/current cfg. */
272 active ? '*' : ' ',
273 desc->bNumInterfaces,
274 desc->bConfigurationValue,
275 desc->bmAttributes,
276 desc->bMaxPower * mul);
277 return start;
278}
279
280static char *usb_dump_config(int speed, char *start, char *end,
281 const struct usb_host_config *config, int active)
282{
283 int i, j;
284 struct usb_interface_cache *intfc;
285 struct usb_interface *interface;
286
287 if (start > end)
288 return start;
289 if (!config)
290 /* getting these some in 2.3.7; none in 2.3.6 */
291 return start + sprintf(start, "(null Cfg. desc.)\n");
292 start = usb_dump_config_descriptor(start, end, &config->desc, active,
293 speed);
294 for (i = 0; i < USB_MAXIADS; i++) {
295 if (config->intf_assoc[i] == NULL)
296 break;
297 start = usb_dump_iad_descriptor(start, end,
298 config->intf_assoc[i]);
299 }
300 for (i = 0; i < config->desc.bNumInterfaces; i++) {
301 intfc = config->intf_cache[i];
302 interface = config->interface[i];
303 for (j = 0; j < intfc->num_altsetting; j++) {
304 start = usb_dump_interface(speed,
305 start, end, intfc, interface, j);
306 }
307 }
308 return start;
309}
310
311/*
312 * Dump the different USB descriptors.
313 */
314static char *usb_dump_device_descriptor(char *start, char *end,
315 const struct usb_device_descriptor *desc)
316{
317 u16 bcdUSB = le16_to_cpu(desc->bcdUSB);
318 u16 bcdDevice = le16_to_cpu(desc->bcdDevice);
319
320 if (start > end)
321 return start;
322 start += sprintf(start, format_device1,
323 bcdUSB >> 8, bcdUSB & 0xff,
324 desc->bDeviceClass,
325 class_decode(desc->bDeviceClass),
326 desc->bDeviceSubClass,
327 desc->bDeviceProtocol,
328 desc->bMaxPacketSize0,
329 desc->bNumConfigurations);
330 if (start > end)
331 return start;
332 start += sprintf(start, format_device2,
333 le16_to_cpu(desc->idVendor),
334 le16_to_cpu(desc->idProduct),
335 bcdDevice >> 8, bcdDevice & 0xff);
336 return start;
337}
338
339/*
340 * Dump the different strings that this device holds.
341 */
342static char *usb_dump_device_strings(char *start, char *end,
343 struct usb_device *dev)
344{
345 if (start > end)
346 return start;
347 if (dev->manufacturer)
348 start += sprintf(start, format_string_manufacturer,
349 dev->manufacturer);
350 if (start > end)
351 goto out;
352 if (dev->product)
353 start += sprintf(start, format_string_product, dev->product);
354 if (start > end)
355 goto out;
356#ifdef ALLOW_SERIAL_NUMBER
357 if (dev->serial)
358 start += sprintf(start, format_string_serialnumber,
359 dev->serial);
360#endif
361 out:
362 return start;
363}
364
365static char *usb_dump_desc(char *start, char *end, struct usb_device *dev)
366{
367 int i;
368
369 start = usb_dump_device_descriptor(start, end, &dev->descriptor);
370
371 start = usb_dump_device_strings(start, end, dev);
372
373 for (i = 0; i < dev->descriptor.bNumConfigurations; i++) {
374 start = usb_dump_config(dev->speed,
375 start, end, dev->config + i,
376 /* active ? */
377 (dev->config + i) == dev->actconfig);
378 }
379 return start;
380}
381
382/*****************************************************************/
383
384/* This is a recursive function. Parameters:
385 * buffer - the user-space buffer to write data into
386 * nbytes - the maximum number of bytes to write
387 * skip_bytes - the number of bytes to skip before writing anything
388 * file_offset - the offset into the devices file on completion
389 * The caller must own the device lock.
390 */
391static ssize_t usb_device_dump(char __user **buffer, size_t *nbytes,
392 loff_t *skip_bytes, loff_t *file_offset,
393 struct usb_device *usbdev, struct usb_bus *bus,
394 int level, int index, int count)
395{
396 int chix;
397 int ret, cnt = 0;
398 int parent_devnum = 0;
399 char *pages_start, *data_end, *speed;
400 unsigned int length;
401 ssize_t total_written = 0;
402 struct usb_device *childdev = NULL;
403
404 /* don't bother with anything else if we're not writing any data */
405 if (*nbytes <= 0)
406 return 0;
407
408 if (level > MAX_TOPO_LEVEL)
409 return 0;
410 /* allocate 2^1 pages = 8K (on i386);
411 * should be more than enough for one device */
412 pages_start = kmalloc(PAGE_SIZE << 1, GFP_NOIO);
413 if (!pages_start)
414 return -ENOMEM;
415
416 if (usbdev->parent && usbdev->parent->devnum != -1)
417 parent_devnum = usbdev->parent->devnum;
418 /*
419 * So the root hub's parent is 0 and any device that is
420 * plugged into the root hub has a parent of 0.
421 */
422 switch (usbdev->speed) {
423 case USB_SPEED_LOW:
424 speed = "1.5"; break;
425 case USB_SPEED_UNKNOWN: /* usb 1.1 root hub code */
426 case USB_SPEED_FULL:
427 speed = "12"; break;
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 kfree(pages_start);
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 kfree(pages_start);
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
510static 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
543const struct file_operations usbfs_devices_fops = {
544 .llseek = no_seek_end_llseek,
545 .read = usb_device_read,
546};