xref: /openbmc/linux/drivers/usb/core/devices.c (revision 1e4c5742)
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 
class_decode(const int class)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 
usb_dump_endpoint_descriptor(int speed,char * start,char * end,const struct usb_endpoint_descriptor * desc)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 
usb_dump_interface_descriptor(char * start,char * end,const struct usb_interface_cache * intfc,const struct usb_interface * iface,int setno)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 
usb_dump_interface(int speed,char * start,char * end,const struct usb_interface_cache * intfc,const struct usb_interface * iface,int setno)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 
usb_dump_iad_descriptor(char * start,char * end,const struct usb_interface_assoc_descriptor * iad)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  */
usb_dump_config_descriptor(char * start,char * end,const struct usb_config_descriptor * desc,int active,int speed)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 
usb_dump_config(int speed,char * start,char * end,const struct usb_host_config * config,int active)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  */
usb_dump_device_descriptor(char * start,char * end,const struct usb_device_descriptor * desc)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  */
usb_dump_device_strings(char * start,char * end,struct usb_device * dev)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 
usb_dump_desc(char * start,char * end,struct usb_device * dev)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  */
usb_device_dump(char __user ** buffer,size_t * nbytes,loff_t * skip_bytes,loff_t * file_offset,struct usb_device * usbdev,struct usb_bus * bus,int level,int index,int count)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_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(pages_start, 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(data_end, 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(data_end, pages_start + (2 * PAGE_SIZE) - 256,
470 				 usbdev);
471 
472 	if (data_end > (pages_start + (2 * PAGE_SIZE) - 256))
473 		data_end += sprintf(data_end, "(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(*buffer, pages_start + *skip_bytes, length)) {
482 			free_pages((unsigned long)pages_start, 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((unsigned long)pages_start, 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, childdev, bus,
500 				      level + 1, chix - 1, ++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 
usb_device_read(struct file * file,char __user * buf,size_t nbytes,loff_t * ppos)509 static 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(&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(&buf, &nbytes, &skip_bytes, ppos,
530 				      bus->root_hub, bus, 0, 0, 0);
531 		usb_unlock_device(bus->root_hub);
532 		if (ret < 0) {
533 			mutex_unlock(&usb_bus_idr_lock);
534 			return ret;
535 		}
536 		total_written += ret;
537 	}
538 	mutex_unlock(&usb_bus_idr_lock);
539 	return total_written;
540 }
541 
542 const struct file_operations usbfs_devices_fops = {
543 	.llseek =	no_seek_end_llseek,
544 	.read =		usb_device_read,
545 };
546