1What:		/sys/bus/usb/devices/<INTERFACE>/authorized
2Date:		August 2015
3Description:
4		This allows to authorize (1) or deauthorize (0)
5		individual interfaces instead a whole device
6		in contrast to the device authorization.
7		If a deauthorized interface will be authorized
8		so the driver probing must be triggered manually
9		by writing INTERFACE to /sys/bus/usb/drivers_probe
10		This allows to avoid side-effects with drivers
11		that need multiple interfaces.
12
13		A deauthorized interface cannot be probed or claimed.
14
15What:		/sys/bus/usb/devices/usbX/interface_authorized_default
16Date:		August 2015
17Description:
18		This is used as value that determines if interfaces
19		would be authorized by default.
20		The value can be 1 or 0. It's by default 1.
21
22What:		/sys/bus/usb/device/.../authorized
23Date:		July 2008
24KernelVersion:	2.6.26
25Contact:	David Vrabel <david.vrabel@csr.com>
26Description:
27		Authorized devices are available for use by device
28		drivers, non-authorized one are not.  By default, wired
29		USB devices are authorized.
30
31		Certified Wireless USB devices are not authorized
32		initially and should be (by writing 1) after the
33		device has been authenticated.
34
35What:		/sys/bus/usb/device/.../wusb_cdid
36Date:		July 2008
37KernelVersion:	2.6.27
38Contact:	David Vrabel <david.vrabel@csr.com>
39Description:
40		For Certified Wireless USB devices only.
41
42		A devices's CDID, as 16 space-separated hex octets.
43
44What:		/sys/bus/usb/device/.../wusb_ck
45Date:		July 2008
46KernelVersion:	2.6.27
47Contact:	David Vrabel <david.vrabel@csr.com>
48Description:
49		For Certified Wireless USB devices only.
50
51		Write the device's connection key (CK) to start the
52		authentication of the device.  The CK is 16
53		space-separated hex octets.
54
55What:		/sys/bus/usb/device/.../wusb_disconnect
56Date:		July 2008
57KernelVersion:	2.6.27
58Contact:	David Vrabel <david.vrabel@csr.com>
59Description:
60		For Certified Wireless USB devices only.
61
62		Write a 1 to force the device to disconnect
63		(equivalent to unplugging a wired USB device).
64
65What:		/sys/bus/usb/drivers/.../new_id
66Date:		October 2011
67Contact:	linux-usb@vger.kernel.org
68Description:
69		Writing a device ID to this file will attempt to
70		dynamically add a new device ID to a USB device driver.
71		This may allow the driver to support more hardware than
72		was included in the driver's static device ID support
73		table at compile time. The format for the device ID is:
74		idVendor idProduct bInterfaceClass RefIdVendor RefIdProduct
75		The vendor ID and device ID fields are required, the
76		rest is optional. The `Ref*` tuple can be used to tell the
77		driver to use the same driver_data for the new device as
78		it is used for the reference device.
79		Upon successfully adding an ID, the driver will probe
80		for the device and attempt to bind to it.  For example::
81
82		  # echo "8086 10f5" > /sys/bus/usb/drivers/foo/new_id
83
84		Here add a new device (0458:7045) using driver_data from
85		an already supported device (0458:704c)::
86
87		  # echo "0458 7045 0 0458 704c" > /sys/bus/usb/drivers/foo/new_id
88
89		Reading from this file will list all dynamically added
90		device IDs in the same format, with one entry per
91		line. For example::
92
93		  # cat /sys/bus/usb/drivers/foo/new_id
94		  8086 10f5
95		  dead beef 06
96		  f00d cafe
97
98		The list will be truncated at PAGE_SIZE bytes due to
99		sysfs restrictions.
100
101What:		/sys/bus/usb-serial/drivers/.../new_id
102Date:		October 2011
103Contact:	linux-usb@vger.kernel.org
104Description:
105		For serial USB drivers, this attribute appears under the
106		extra bus folder "usb-serial" in sysfs; apart from that
107		difference, all descriptions from the entry
108		"/sys/bus/usb/drivers/.../new_id" apply.
109
110What:		/sys/bus/usb/drivers/.../remove_id
111Date:		November 2009
112Contact:	CHENG Renquan <rqcheng@smu.edu.sg>
113Description:
114		Writing a device ID to this file will remove an ID
115		that was dynamically added via the new_id sysfs entry.
116		The format for the device ID is:
117		idVendor idProduct.	After successfully
118		removing an ID, the driver will no longer support the
119		device.  This is useful to ensure auto probing won't
120		match the driver to the device.  For example:
121		# echo "046d c315" > /sys/bus/usb/drivers/foo/remove_id
122
123		Reading from this file will list the dynamically added
124		device IDs, exactly like reading from the entry
125		"/sys/bus/usb/drivers/.../new_id"
126
127What:		/sys/bus/usb/devices/.../power/usb2_hardware_lpm
128Date:		September 2011
129Contact:	Andiry Xu <andiry.xu@amd.com>
130Description:
131		If CONFIG_PM is set and a USB 2.0 lpm-capable device is plugged
132		in to a xHCI host which support link PM, it will perform a LPM
133		test; if the test is passed and host supports USB2 hardware LPM
134		(xHCI 1.0 feature), USB2 hardware LPM will be enabled for the
135		device and the USB device directory will contain a file named
136		power/usb2_hardware_lpm.  The file holds a string value (enable
137		or disable) indicating whether or not USB2 hardware LPM is
138		enabled for the device. Developer can write y/Y/1 or n/N/0 to
139		the file to enable/disable the feature.
140
141What:		/sys/bus/usb/devices/.../power/usb3_hardware_lpm_u1
142		/sys/bus/usb/devices/.../power/usb3_hardware_lpm_u2
143Date:		November 2015
144Contact:	Kevin Strasser <kevin.strasser@linux.intel.com>
145		Lu Baolu <baolu.lu@linux.intel.com>
146Description:
147		If CONFIG_PM is set and a USB 3.0 lpm-capable device is plugged
148		in to a xHCI host which supports link PM, it will check if U1
149		and U2 exit latencies have been set in the BOS descriptor; if
150		the check is passed and the host supports USB3 hardware LPM,
151		USB3 hardware LPM will be enabled for the device and the USB
152		device directory will contain two files named
153		power/usb3_hardware_lpm_u1 and power/usb3_hardware_lpm_u2. These
154		files hold a string value (enable or disable) indicating whether
155		or not USB3 hardware LPM U1 or U2 is enabled for the device.
156
157What:		/sys/bus/usb/devices/.../ltm_capable
158Date:		July 2012
159Contact:	Sarah Sharp <sarah.a.sharp@linux.intel.com>
160Description:
161		USB 3.0 devices may optionally support Latency Tolerance
162		Messaging (LTM).  They indicate their support by setting a bit
163		in the bmAttributes field of their SuperSpeed BOS descriptors.
164		If that bit is set for the device, ltm_capable will read "yes".
165		If the device doesn't support LTM, the file will read "no".
166		The file will be present for all speeds of USB devices, and will
167		always read "no" for USB 1.1 and USB 2.0 devices.
168
169What:		/sys/bus/usb/devices/.../<hub_interface>/port<X>
170Date:		August 2012
171Contact:	Lan Tianyu <tianyu.lan@intel.com>
172Description:
173		The /sys/bus/usb/devices/.../<hub_interface>/port<X>
174		is usb port device's sysfs directory.
175
176What:		/sys/bus/usb/devices/.../<hub_interface>/port<X>/connect_type
177Date:		January 2013
178Contact:	Lan Tianyu <tianyu.lan@intel.com>
179Description:
180		Some platforms provide usb port connect types through ACPI.
181		This attribute is to expose these information to user space.
182		The file will read "hotplug", "hardwired" and "not used" if the
183		information is available, and "unknown" otherwise.
184
185What:		/sys/bus/usb/devices/.../<hub_interface>/port<X>/location
186Date:		October 2018
187Contact:	Bjørn Mork <bjorn@mork.no>
188Description:
189		Some platforms provide usb port physical location through
190		firmware. This is used by the kernel to pair up logical ports
191		mapping to the same physical connector. The attribute exposes the
192		raw location value as a hex integer.
193
194
195What:		/sys/bus/usb/devices/.../<hub_interface>/port<X>/quirks
196Date:		May 2018
197Contact:	Nicolas Boichat <drinkcat@chromium.org>
198Description:
199		In some cases, we care about time-to-active for devices
200		connected on a specific port (e.g. non-standard USB port like
201		pogo pins), where the device to be connected is known in
202		advance, and behaves well according to the specification.
203		This attribute is a bit-field that controls the behavior of
204		a specific port:
205
206		 - Bit 0 of this field selects the "old" enumeration scheme,
207		   as it is considerably faster (it only causes one USB reset
208		   instead of 2).
209
210		   The old enumeration scheme can also be selected globally
211		   using /sys/module/usbcore/parameters/old_scheme_first, but
212		   it is often not desirable as the new scheme was introduced to
213		   increase compatibility with more devices.
214		 - Bit 1 reduces TRSTRCY to the 10 ms that are required by the
215		   USB 2.0 specification, instead of the 50 ms that are normally
216		   used to help make enumeration work better on some high speed
217		   devices.
218
219What:		/sys/bus/usb/devices/.../<hub_interface>/port<X>/over_current_count
220Date:		February 2018
221Contact:	Richard Leitner <richard.leitner@skidata.com>
222Description:
223		Most hubs are able to detect over-current situations on their
224		ports and report them to the kernel. This attribute is to expose
225		the number of over-current situation occurred on a specific port
226		to user space. This file will contain an unsigned 32 bit value
227		which wraps to 0 after its maximum is reached. This file supports
228		poll() for monitoring changes to this value in user space.
229
230		Any time this value changes the corresponding hub device will send a
231		udev event with the following attributes::
232
233		  OVER_CURRENT_PORT=/sys/bus/usb/devices/.../<hub_interface>/port<X>
234		  OVER_CURRENT_COUNT=[current value of this sysfs attribute]
235
236What:		/sys/bus/usb/devices/.../<hub_interface>/port<X>/usb3_lpm_permit
237Date:		November 2015
238Contact:	Lu Baolu <baolu.lu@linux.intel.com>
239Description:
240		Some USB3.0 devices are not friendly to USB3 LPM.  usb3_lpm_permit
241		attribute allows enabling/disabling usb3 lpm of a port. It takes
242		effect both before and after a usb device is enumerated. Supported
243		values are "0" if both u1 and u2 are NOT permitted, "u1" if only u1
244		is permitted, "u2" if only u2 is permitted, "u1_u2" if both u1 and
245		u2 are permitted.
246
247What:		/sys/bus/usb/devices/.../<hub_interface>/port<X>/connector
248Date:		December 2021
249Contact:	Heikki Krogerus <heikki.krogerus@linux.intel.com>
250Description:
251		Link to the USB Type-C connector when available. This link is
252		only created when USB Type-C Connector Class is enabled, and
253		only if the system firmware is capable of describing the
254		connection between a port and its connector.
255
256What:		/sys/bus/usb/devices/.../power/usb2_lpm_l1_timeout
257Date:		May 2013
258Contact:	Mathias Nyman <mathias.nyman@linux.intel.com>
259Description:
260		USB 2.0 devices may support hardware link power management (LPM)
261		L1 sleep state. The usb2_lpm_l1_timeout attribute allows
262		tuning the timeout for L1 inactivity timer (LPM timer), e.g.
263		needed inactivity time before host requests the device to go to L1 sleep.
264		Useful for power management tuning.
265		Supported values are 0 - 65535 microseconds.
266
267What:		/sys/bus/usb/devices/.../power/usb2_lpm_besl
268Date:		May 2013
269Contact:	Mathias Nyman <mathias.nyman@linux.intel.com>
270Description:
271		USB 2.0 devices that support hardware link power management (LPM)
272		L1 sleep state now use a best effort service latency value (BESL) to
273		indicate the best effort to resumption of service to the device after the
274		initiation of the resume event.
275		If the device does not have a preferred besl value then the host can select
276		one instead. This usb2_lpm_besl attribute allows to tune the host selected besl
277		value in order to tune power saving and service latency.
278
279		Supported values are 0 - 15.
280		More information on how besl values map to microseconds can be found in
281		USB 2.0 ECN Errata for Link Power Management, section 4.10)
282
283What:		/sys/bus/usb/devices/.../rx_lanes
284Date:		March 2018
285Contact:	Mathias Nyman <mathias.nyman@linux.intel.com>
286Description:
287		Number of rx lanes the device is using.
288		USB 3.2 adds Dual-lane support, 2 rx and 2 tx lanes over Type-C.
289		Inter-Chip SSIC devices support asymmetric lanes up to 4 lanes per
290		direction. Devices before USB 3.2 are single lane (rx_lanes = 1)
291
292What:		/sys/bus/usb/devices/.../tx_lanes
293Date:		March 2018
294Contact:	Mathias Nyman <mathias.nyman@linux.intel.com>
295Description:
296		Number of tx lanes the device is using.
297		USB 3.2 adds Dual-lane support, 2 rx and 2 tx -lanes over Type-C.
298		Inter-Chip SSIC devices support asymmetric lanes up to 4 lanes per
299		direction. Devices before USB 3.2 are single lane (tx_lanes = 1)
300
301What:		/sys/bus/usb/devices/usbX/bAlternateSetting
302Description:
303		The current interface alternate setting number, in decimal.
304
305		See USB specs for its meaning.
306
307What:		/sys/bus/usb/devices/usbX/bcdDevice
308Description:
309		The device's release number, in hexadecimal.
310
311		See USB specs for its meaning.
312
313What:		/sys/bus/usb/devices/usbX/bConfigurationValue
314Description:
315		While a USB device typically have just one configuration
316		setting, some devices support multiple configurations.
317
318		This value shows the current configuration, in decimal.
319
320		Changing its value will change the device's configuration
321		to another setting.
322
323		The number of configurations supported by a device is at:
324
325			/sys/bus/usb/devices/usbX/bNumConfigurations
326
327		See USB specs for its meaning.
328
329What:		/sys/bus/usb/devices/usbX/bDeviceClass
330Description:
331		Class code of the device, in hexadecimal.
332
333		See USB specs for its meaning.
334
335What:		/sys/bus/usb/devices/usbX/bDeviceProtocol
336Description:
337		Protocol code of the device, in hexadecimal.
338
339		See USB specs for its meaning.
340
341What:		/sys/bus/usb/devices/usbX/bDeviceSubClass
342Description:
343		Subclass code of the device, in hexadecimal.
344
345		See USB specs for its meaning.
346
347What:		/sys/bus/usb/devices/usbX/bInterfaceClass
348Description:
349		Class code of the interface, in hexadecimal.
350
351		See USB specs for its meaning.
352
353What:		/sys/bus/usb/devices/usbX/bInterfaceNumber
354Description:
355		Interface number, in hexadecimal.
356
357		See USB specs for its meaning.
358
359What:		/sys/bus/usb/devices/usbX/bInterfaceProtocol
360Description:
361		Protocol code of the interface, in hexadecimal.
362
363		See USB specs for its meaning.
364
365What:		/sys/bus/usb/devices/usbX/bInterfaceSubClass
366Description:
367		Subclass code of the interface, in hexadecimal.
368
369		See USB specs for its meaning.
370
371What:		/sys/bus/usb/devices/usbX/bmAttributes
372Description:
373		Attributes of the current configuration, in hexadecimal.
374
375		See USB specs for its meaning.
376
377What:		/sys/bus/usb/devices/usbX/bMaxPacketSize0
378Description:
379		Maximum endpoint 0 packet size, in decimal.
380
381		See USB specs for its meaning.
382
383What:		/sys/bus/usb/devices/usbX/bMaxPower
384Description:
385		Maximum power consumption of the active configuration of
386		the device, in miliamperes.
387
388What:		/sys/bus/usb/devices/usbX/bNumConfigurations
389Description:
390		Number of the possible configurations of the device, in
391		decimal. The current configuration is controlled via:
392
393			/sys/bus/usb/devices/usbX/bConfigurationValue
394
395		See USB specs for its meaning.
396
397What:		/sys/bus/usb/devices/usbX/bNumEndpoints
398Description:
399		Number of endpoints used on this interface, in hexadecimal.
400
401		See USB specs for its meaning.
402
403What:		/sys/bus/usb/devices/usbX/bNumInterfaces
404Description:
405		Number of interfaces on this device, in decimal.
406
407What:		/sys/bus/usb/devices/usbX/busnum
408Description:
409		Number of the bus.
410
411What:		/sys/bus/usb/devices/usbX/configuration
412Description:
413		Contents of the string descriptor associated with the
414		current configuration. It may include the firmware version
415		of a device and/or its serial number.
416
417What:		/sys/bus/usb/devices/usbX/descriptors
418Description:
419		Contains the interface descriptors, in binary.
420
421What:		/sys/bus/usb/devices/usbX/idProduct
422Description:
423		Product ID, in hexadecimal.
424
425What:		/sys/bus/usb/devices/usbX/idVendor
426Description:
427		Vendor ID, in hexadecimal.
428
429What:		/sys/bus/usb/devices/usbX/devspec
430Description:
431		Displays the Device Tree Open Firmware node of the interface.
432
433What:		/sys/bus/usb/devices/usbX/avoid_reset_quirk
434Description:
435		Most devices have this set to zero.
436
437		If the value is 1, enable a USB quirk that prevents this
438		device to use reset.
439
440		(read/write)
441
442What:		/sys/bus/usb/devices/usbX/devnum
443Description:
444		USB interface device number, in decimal.
445
446What:		/sys/bus/usb/devices/usbX/devpath
447Description:
448		String containing the USB interface device path.
449
450What:		/sys/bus/usb/devices/usbX/manufacturer
451Description:
452		Vendor specific string containing the name of the
453		manufacturer of the device.
454
455What:		/sys/bus/usb/devices/usbX/maxchild
456Description:
457		Number of ports of an USB hub
458
459What:		/sys/bus/usb/devices/usbX/persist
460Description:
461		Keeps the device even if it gets disconnected.
462
463What:		/sys/bus/usb/devices/usbX/product
464Description:
465		Vendor specific string containing the name of the
466		device's product.
467
468What:		/sys/bus/usb/devices/usbX/speed
469Description:
470		Shows the device's max speed, according to the USB version,
471		in Mbps.
472		Can be:
473
474			=======		====================
475			Unknown		speed unknown
476			1.5		Low speed
477			15		Full speed
478			480		High Speed
479			5000		Super Speed
480			10000		Super Speed+
481			20000		Super Speed+ Gen 2x2
482			=======		====================
483
484What:		/sys/bus/usb/devices/usbX/supports_autosuspend
485Description:
486		Returns 1 if the device doesn't support autosuspend.
487		Otherwise, returns 0.
488
489What:		/sys/bus/usb/devices/usbX/urbnum
490Description:
491		Number of URBs submitted for the whole device.
492
493What:		/sys/bus/usb/devices/usbX/version
494Description:
495		String containing the USB device version, as encoded
496		at the BCD descriptor.
497
498What:		/sys/bus/usb/devices/usbX/power/autosuspend
499Description:
500		Time in milliseconds for the device to autosuspend. If the
501		value is negative, then autosuspend is prevented.
502
503		(read/write)
504
505What:		/sys/bus/usb/devices/usbX/power/active_duration
506Description:
507		The total time the device has not been suspended.
508
509What:		/sys/bus/usb/devices/usbX/power/connected_duration
510Description:
511		The total time (in msec) that the device has been connected.
512
513What:		/sys/bus/usb/devices/usbX/power/level
514Description:
515
516What:		/sys/bus/usb/devices/usbX/ep_<N>/bEndpointAddress
517Description:
518		The address of the endpoint described by this descriptor,
519		in hexadecimal. The endpoint direction on this bitmapped field
520		is also shown at:
521
522			/sys/bus/usb/devices/usbX/ep_<N>/direction
523
524		See USB specs for its meaning.
525
526What:		/sys/bus/usb/devices/usbX/ep_<N>/bInterval
527Description:
528		The interval of the endpoint as described on its descriptor,
529		in hexadecimal. The actual interval depends on the version
530		of the USB. Also shown in time units at
531		/sys/bus/usb/devices/usbX/ep_<N>/interval.
532
533What:		/sys/bus/usb/devices/usbX/ep_<N>/bLength
534Description:
535		Number of bytes of the endpoint descriptor, in hexadecimal.
536
537What:		/sys/bus/usb/devices/usbX/ep_<N>/bmAttributes
538Description:
539		Attributes which apply to the endpoint as described on its
540		descriptor, in hexadecimal. The endpoint type on this
541		bitmapped field is also shown at:
542
543			/sys/bus/usb/devices/usbX/ep_<N>/type
544
545		See USB specs for its meaning.
546
547What:		/sys/bus/usb/devices/usbX/ep_<N>/direction
548Description:
549		Direction of the endpoint. Can be:
550
551		    - both (on control endpoints)
552		    - in
553		    - out
554
555What:		/sys/bus/usb/devices/usbX/ep_<N>/interval
556Description:
557		Interval for polling endpoint for data transfers, in
558		milisseconds or microseconds.
559
560What:		/sys/bus/usb/devices/usbX/ep_<N>/type
561Description:
562		Descriptor type. Can be:
563
564		    - Control
565		    - Isoc
566		    - Bulk
567		    - Interrupt
568		    - unknown
569
570What:		/sys/bus/usb/devices/usbX/ep_<N>/wMaxPacketSize
571Description:
572		Maximum packet size this endpoint is capable of
573		sending or receiving, in hexadecimal.
574