1 What: /sys/bus/usb/devices/<INTERFAC 1 What: /sys/bus/usb/devices/<INTERFACE>/authorized
2 Date: August 2015 2 Date: August 2015
3 Description: 3 Description:
4 This allows to authorize (1) o 4 This allows to authorize (1) or deauthorize (0)
5 individual interfaces instead 5 individual interfaces instead a whole device
6 in contrast to the device auth 6 in contrast to the device authorization.
7 If a deauthorized interface wi 7 If a deauthorized interface will be authorized
8 so the driver probing must be 8 so the driver probing must be triggered manually
9 by writing INTERFACE to /sys/b 9 by writing INTERFACE to /sys/bus/usb/drivers_probe
10 This allows to avoid side-effe 10 This allows to avoid side-effects with drivers
11 that need multiple interfaces. 11 that need multiple interfaces.
12 12
13 A deauthorized interface canno 13 A deauthorized interface cannot be probed or claimed.
14 14
15 What: /sys/bus/usb/devices/usbX/inte 15 What: /sys/bus/usb/devices/usbX/interface_authorized_default
16 Date: August 2015 16 Date: August 2015
17 Description: 17 Description:
18 This is used as value that det 18 This is used as value that determines if interfaces
19 would be authorized by default 19 would be authorized by default.
20 The value can be 1 or 0. It's 20 The value can be 1 or 0. It's by default 1.
21 21
22 What: /sys/bus/usb/device/.../author 22 What: /sys/bus/usb/device/.../authorized
23 Date: July 2008 23 Date: July 2008
24 KernelVersion: 2.6.26 24 KernelVersion: 2.6.26
25 Contact: David Vrabel <david.vrabel@csr. 25 Contact: David Vrabel <david.vrabel@csr.com>
26 Description: 26 Description:
27 Authorized devices are availab 27 Authorized devices are available for use by device
28 drivers, non-authorized one ar 28 drivers, non-authorized one are not. By default, wired
29 USB devices are authorized. 29 USB devices are authorized.
30 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
>> 35 What: /sys/bus/usb/device/.../wusb_cdid
>> 36 Date: July 2008
>> 37 KernelVersion: 2.6.27
>> 38 Contact: David Vrabel <david.vrabel@csr.com>
>> 39 Description:
>> 40 For Certified Wireless USB devices only.
>> 41
>> 42 A devices's CDID, as 16 space-separated hex octets.
>> 43
>> 44 What: /sys/bus/usb/device/.../wusb_ck
>> 45 Date: July 2008
>> 46 KernelVersion: 2.6.27
>> 47 Contact: David Vrabel <david.vrabel@csr.com>
>> 48 Description:
>> 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
>> 55 What: /sys/bus/usb/device/.../wusb_disconnect
>> 56 Date: July 2008
>> 57 KernelVersion: 2.6.27
>> 58 Contact: David Vrabel <david.vrabel@csr.com>
>> 59 Description:
>> 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
31 What: /sys/bus/usb/drivers/.../new_i 65 What: /sys/bus/usb/drivers/.../new_id
32 Date: October 2011 66 Date: October 2011
33 Contact: linux-usb@vger.kernel.org 67 Contact: linux-usb@vger.kernel.org
34 Description: 68 Description:
35 Writing a device ID to this fi 69 Writing a device ID to this file will attempt to
36 dynamically add a new device I 70 dynamically add a new device ID to a USB device driver.
37 This may allow the driver to s 71 This may allow the driver to support more hardware than
38 was included in the driver's s 72 was included in the driver's static device ID support
39 table at compile time. The for 73 table at compile time. The format for the device ID is:
40 idVendor idProduct bInterfaceC 74 idVendor idProduct bInterfaceClass RefIdVendor RefIdProduct
41 The vendor ID and device ID fi 75 The vendor ID and device ID fields are required, the
42 rest is optional. The `Ref*` t 76 rest is optional. The `Ref*` tuple can be used to tell the
43 driver to use the same driver_ 77 driver to use the same driver_data for the new device as
44 it is used for the reference d 78 it is used for the reference device.
45 Upon successfully adding an ID 79 Upon successfully adding an ID, the driver will probe
46 for the device and attempt to 80 for the device and attempt to bind to it. For example::
47 81
48 # echo "8086 10f5" > /sys/bu 82 # echo "8086 10f5" > /sys/bus/usb/drivers/foo/new_id
49 83
50 Here add a new device (0458:70 84 Here add a new device (0458:7045) using driver_data from
51 an already supported device (0 85 an already supported device (0458:704c)::
52 86
53 # echo "0458 7045 0 0458 704 87 # echo "0458 7045 0 0458 704c" > /sys/bus/usb/drivers/foo/new_id
54 88
55 Reading from this file will li 89 Reading from this file will list all dynamically added
56 device IDs in the same format, 90 device IDs in the same format, with one entry per
57 line. For example:: 91 line. For example::
58 92
59 # cat /sys/bus/usb/drivers/f 93 # cat /sys/bus/usb/drivers/foo/new_id
60 8086 10f5 94 8086 10f5
61 dead beef 06 95 dead beef 06
62 f00d cafe 96 f00d cafe
63 97
64 The list will be truncated at 98 The list will be truncated at PAGE_SIZE bytes due to
65 sysfs restrictions. 99 sysfs restrictions.
66 100
67 What: /sys/bus/usb-serial/drivers/.. 101 What: /sys/bus/usb-serial/drivers/.../new_id
68 Date: October 2011 102 Date: October 2011
69 Contact: linux-usb@vger.kernel.org 103 Contact: linux-usb@vger.kernel.org
70 Description: 104 Description:
71 For serial USB drivers, this a 105 For serial USB drivers, this attribute appears under the
72 extra bus folder "usb-serial" 106 extra bus folder "usb-serial" in sysfs; apart from that
73 difference, all descriptions f 107 difference, all descriptions from the entry
74 "/sys/bus/usb/drivers/.../new_ 108 "/sys/bus/usb/drivers/.../new_id" apply.
75 109
76 What: /sys/bus/usb/drivers/.../remov 110 What: /sys/bus/usb/drivers/.../remove_id
77 Date: November 2009 111 Date: November 2009
78 Contact: CHENG Renquan <rqcheng@smu.edu. 112 Contact: CHENG Renquan <rqcheng@smu.edu.sg>
79 Description: 113 Description:
80 Writing a device ID to this fi 114 Writing a device ID to this file will remove an ID
81 that was dynamically added via 115 that was dynamically added via the new_id sysfs entry.
82 The format for the device ID i 116 The format for the device ID is:
83 idVendor idProduct. After 117 idVendor idProduct. After successfully
84 removing an ID, the driver wil 118 removing an ID, the driver will no longer support the
85 device. This is useful to ens 119 device. This is useful to ensure auto probing won't
86 match the driver to the device 120 match the driver to the device. For example:
87 # echo "046d c315" > /sys/bus/ 121 # echo "046d c315" > /sys/bus/usb/drivers/foo/remove_id
88 122
89 Reading from this file will li 123 Reading from this file will list the dynamically added
90 device IDs, exactly like readi 124 device IDs, exactly like reading from the entry
91 "/sys/bus/usb/drivers/.../new_ 125 "/sys/bus/usb/drivers/.../new_id"
92 126
93 What: /sys/bus/usb/devices/.../power 127 What: /sys/bus/usb/devices/.../power/usb2_hardware_lpm
94 Date: September 2011 128 Date: September 2011
95 Contact: Andiry Xu <andiry.xu@amd.com> 129 Contact: Andiry Xu <andiry.xu@amd.com>
96 Description: 130 Description:
97 If CONFIG_PM is set and a USB 131 If CONFIG_PM is set and a USB 2.0 lpm-capable device is plugged
98 in to a xHCI host which suppor 132 in to a xHCI host which support link PM, it will perform a LPM
99 test; if the test is passed an 133 test; if the test is passed and host supports USB2 hardware LPM
100 (xHCI 1.0 feature), USB2 hardw 134 (xHCI 1.0 feature), USB2 hardware LPM will be enabled for the
101 device and the USB device dire 135 device and the USB device directory will contain a file named
102 power/usb2_hardware_lpm. The 136 power/usb2_hardware_lpm. The file holds a string value (enable
103 or disable) indicating whether 137 or disable) indicating whether or not USB2 hardware LPM is
104 enabled for the device. Develo 138 enabled for the device. Developer can write y/Y/1 or n/N/0 to
105 the file to enable/disable the 139 the file to enable/disable the feature.
106 140
107 What: /sys/bus/usb/devices/.../power 141 What: /sys/bus/usb/devices/.../power/usb3_hardware_lpm_u1
108 /sys/bus/usb/devices/.../power 142 /sys/bus/usb/devices/.../power/usb3_hardware_lpm_u2
109 Date: November 2015 143 Date: November 2015
110 Contact: Kevin Strasser <kevin.strasser@ 144 Contact: Kevin Strasser <kevin.strasser@linux.intel.com>
111 Lu Baolu <baolu.lu@linux.intel. 145 Lu Baolu <baolu.lu@linux.intel.com>
112 Description: 146 Description:
113 If CONFIG_PM is set and a USB 147 If CONFIG_PM is set and a USB 3.0 lpm-capable device is plugged
114 in to a xHCI host which suppor 148 in to a xHCI host which supports link PM, it will check if U1
115 and U2 exit latencies have bee 149 and U2 exit latencies have been set in the BOS descriptor; if
116 the check is passed and the ho 150 the check is passed and the host supports USB3 hardware LPM,
117 USB3 hardware LPM will be enab 151 USB3 hardware LPM will be enabled for the device and the USB
118 device directory will contain 152 device directory will contain two files named
119 power/usb3_hardware_lpm_u1 and 153 power/usb3_hardware_lpm_u1 and power/usb3_hardware_lpm_u2. These
120 files hold a string value (ena 154 files hold a string value (enable or disable) indicating whether
121 or not USB3 hardware LPM U1 or 155 or not USB3 hardware LPM U1 or U2 is enabled for the device.
122 156
123 What: /sys/bus/usb/devices/.../ltm_c 157 What: /sys/bus/usb/devices/.../ltm_capable
124 Date: July 2012 158 Date: July 2012
125 Contact: Sarah Sharp <sarah.a.sharp@linu 159 Contact: Sarah Sharp <sarah.a.sharp@linux.intel.com>
126 Description: 160 Description:
127 USB 3.0 devices may optionally 161 USB 3.0 devices may optionally support Latency Tolerance
128 Messaging (LTM). They indicat 162 Messaging (LTM). They indicate their support by setting a bit
129 in the bmAttributes field of t 163 in the bmAttributes field of their SuperSpeed BOS descriptors.
130 If that bit is set for the dev 164 If that bit is set for the device, ltm_capable will read "yes".
131 If the device doesn't support 165 If the device doesn't support LTM, the file will read "no".
132 The file will be present for a 166 The file will be present for all speeds of USB devices, and will
133 always read "no" for USB 1.1 a 167 always read "no" for USB 1.1 and USB 2.0 devices.
134 168
135 What: /sys/bus/usb/devices/<INTERFAC 169 What: /sys/bus/usb/devices/<INTERFACE>/wireless_status
136 Date: February 2023 170 Date: February 2023
137 Contact: Bastien Nocera <hadess@hadess.n 171 Contact: Bastien Nocera <hadess@hadess.net>
138 Description: 172 Description:
139 Some USB devices use a USB rec 173 Some USB devices use a USB receiver dongle to communicate
140 wirelessly with their device u 174 wirelessly with their device using proprietary protocols. This
141 attribute allows user-space to 175 attribute allows user-space to know whether the device is
142 connected to its receiver dong 176 connected to its receiver dongle, and, for example, consider
143 the device to be absent when c 177 the device to be absent when choosing whether to show the
144 device's battery, show a heads 178 device's battery, show a headset in a list of outputs, or show
145 an on-screen keyboard if the o 179 an on-screen keyboard if the only wireless keyboard is
146 turned off. 180 turned off.
147 This attribute is not to be us 181 This attribute is not to be used to replace protocol specific
148 statuses available in WWAN, WL 182 statuses available in WWAN, WLAN/Wi-Fi, Bluetooth, etc.
149 If the device does not use a r 183 If the device does not use a receiver dongle with a wireless
150 device, then this attribute wi 184 device, then this attribute will not exist.
151 185
152 What: /sys/bus/usb/devices/.../<hub_ 186 What: /sys/bus/usb/devices/.../<hub_interface>/port<X>
153 Date: August 2012 187 Date: August 2012
154 Contact: Lan Tianyu <tianyu.lan@intel.co 188 Contact: Lan Tianyu <tianyu.lan@intel.com>
155 Description: 189 Description:
156 The /sys/bus/usb/devices/.../< 190 The /sys/bus/usb/devices/.../<hub_interface>/port<X>
157 is usb port device's sysfs dir 191 is usb port device's sysfs directory.
158 192
159 What: /sys/bus/usb/devices/.../<hub_ 193 What: /sys/bus/usb/devices/.../<hub_interface>/port<X>/connect_type
160 Date: January 2013 194 Date: January 2013
161 Contact: Lan Tianyu <tianyu.lan@intel.co 195 Contact: Lan Tianyu <tianyu.lan@intel.com>
162 Description: 196 Description:
163 Some platforms provide usb por 197 Some platforms provide usb port connect types through ACPI.
164 This attribute is to expose th 198 This attribute is to expose these information to user space.
165 The file will read "hotplug", 199 The file will read "hotplug", "hardwired" and "not used" if the
166 information is available, and 200 information is available, and "unknown" otherwise.
167 201
168 What: /sys/bus/usb/devices/.../<hub_ 202 What: /sys/bus/usb/devices/.../<hub_interface>/port<X>/location
169 Date: October 2018 203 Date: October 2018
170 Contact: Bjørn Mork <bjorn@mork.no> 204 Contact: Bjørn Mork <bjorn@mork.no>
171 Description: 205 Description:
172 Some platforms provide usb por 206 Some platforms provide usb port physical location through
173 firmware. This is used by the 207 firmware. This is used by the kernel to pair up logical ports
174 mapping to the same physical c 208 mapping to the same physical connector. The attribute exposes the
175 raw location value as a hex in 209 raw location value as a hex integer.
176 210
177 211
178 What: /sys/bus/usb/devices/.../<hub_ 212 What: /sys/bus/usb/devices/.../<hub_interface>/port<X>/quirks
179 Date: May 2018 213 Date: May 2018
180 Contact: Nicolas Boichat <drinkcat@chrom 214 Contact: Nicolas Boichat <drinkcat@chromium.org>
181 Description: 215 Description:
182 In some cases, we care about t 216 In some cases, we care about time-to-active for devices
183 connected on a specific port ( 217 connected on a specific port (e.g. non-standard USB port like
184 pogo pins), where the device t 218 pogo pins), where the device to be connected is known in
185 advance, and behaves well acco 219 advance, and behaves well according to the specification.
186 This attribute is a bit-field 220 This attribute is a bit-field that controls the behavior of
187 a specific port: 221 a specific port:
188 222
189 - Bit 0 of this field selects 223 - Bit 0 of this field selects the "old" enumeration scheme,
190 as it is considerably faste 224 as it is considerably faster (it only causes one USB reset
191 instead of 2). 225 instead of 2).
192 226
193 The old enumeration scheme 227 The old enumeration scheme can also be selected globally
194 using /sys/module/usbcore/p 228 using /sys/module/usbcore/parameters/old_scheme_first, but
195 it is often not desirable a 229 it is often not desirable as the new scheme was introduced to
196 increase compatibility with 230 increase compatibility with more devices.
197 - Bit 1 reduces TRSTRCY to th 231 - Bit 1 reduces TRSTRCY to the 10 ms that are required by the
198 USB 2.0 specification, inst 232 USB 2.0 specification, instead of the 50 ms that are normally
199 used to help make enumerati 233 used to help make enumeration work better on some high speed
200 devices. 234 devices.
201 235
202 What: /sys/bus/usb/devices/.../<hub_ 236 What: /sys/bus/usb/devices/.../<hub_interface>/port<X>/over_current_count
203 Date: February 2018 237 Date: February 2018
204 Contact: Richard Leitner <richard.leitne 238 Contact: Richard Leitner <richard.leitner@skidata.com>
205 Description: 239 Description:
206 Most hubs are able to detect o 240 Most hubs are able to detect over-current situations on their
207 ports and report them to the k 241 ports and report them to the kernel. This attribute is to expose
208 the number of over-current sit 242 the number of over-current situation occurred on a specific port
209 to user space. This file will 243 to user space. This file will contain an unsigned 32 bit value
210 which wraps to 0 after its max 244 which wraps to 0 after its maximum is reached. This file supports
211 poll() for monitoring changes 245 poll() for monitoring changes to this value in user space.
212 246
213 Any time this value changes th 247 Any time this value changes the corresponding hub device will send a
214 udev event with the following 248 udev event with the following attributes::
215 249
216 OVER_CURRENT_PORT=/sys/bus/u 250 OVER_CURRENT_PORT=/sys/bus/usb/devices/.../<hub_interface>/port<X>
217 OVER_CURRENT_COUNT=[current 251 OVER_CURRENT_COUNT=[current value of this sysfs attribute]
218 252
219 What: /sys/bus/usb/devices/.../<hub_ 253 What: /sys/bus/usb/devices/.../<hub_interface>/port<X>/usb3_lpm_permit
220 Date: November 2015 254 Date: November 2015
221 Contact: Lu Baolu <baolu.lu@linux.intel. 255 Contact: Lu Baolu <baolu.lu@linux.intel.com>
222 Description: 256 Description:
223 Some USB3.0 devices are not fr 257 Some USB3.0 devices are not friendly to USB3 LPM. usb3_lpm_permit
224 attribute allows enabling/disa 258 attribute allows enabling/disabling usb3 lpm of a port. It takes
225 effect both before and after a 259 effect both before and after a usb device is enumerated. Supported
226 values are "0" if both u1 and 260 values are "0" if both u1 and u2 are NOT permitted, "u1" if only u1
227 is permitted, "u2" if only u2 261 is permitted, "u2" if only u2 is permitted, "u1_u2" if both u1 and
228 u2 are permitted. 262 u2 are permitted.
229 263
230 What: /sys/bus/usb/devices/.../<hub_ 264 What: /sys/bus/usb/devices/.../<hub_interface>/port<X>/connector
231 Date: December 2021 265 Date: December 2021
232 Contact: Heikki Krogerus <heikki.krogeru 266 Contact: Heikki Krogerus <heikki.krogerus@linux.intel.com>
233 Description: 267 Description:
234 Link to the USB Type-C connect 268 Link to the USB Type-C connector when available. This link is
235 only created when USB Type-C C 269 only created when USB Type-C Connector Class is enabled, and
236 only if the system firmware is 270 only if the system firmware is capable of describing the
237 connection between a port and 271 connection between a port and its connector.
238 272
239 What: /sys/bus/usb/devices/.../<hub_ 273 What: /sys/bus/usb/devices/.../<hub_interface>/port<X>/disable
240 Date: June 2022 274 Date: June 2022
241 Contact: Michael Grzeschik <m.grzeschik@ 275 Contact: Michael Grzeschik <m.grzeschik@pengutronix.de>
242 Description: 276 Description:
243 This file controls the state o 277 This file controls the state of a USB port, including
244 Vbus power output (but only on 278 Vbus power output (but only on hubs that support
245 power switching -- most hubs d 279 power switching -- most hubs don't support it). If
246 a port is disabled, the port i 280 a port is disabled, the port is unusable: Devices
247 attached to the port will not 281 attached to the port will not be detected, initialized,
248 or enumerated. 282 or enumerated.
249 283
250 What: /sys/bus/usb/devices/.../<hub_ 284 What: /sys/bus/usb/devices/.../<hub_interface>/port<X>/early_stop
251 Date: Sep 2022 285 Date: Sep 2022
252 Contact: Ray Chi <raychi@google.com> 286 Contact: Ray Chi <raychi@google.com>
253 Description: 287 Description:
254 Some USB hosts have some watch 288 Some USB hosts have some watchdog mechanisms so that the device
255 may enter ramdump if it takes 289 may enter ramdump if it takes a long time during port initialization.
256 This attribute allows each por 290 This attribute allows each port just has two attempts so that the
257 port initialization will be fa 291 port initialization will be failed quickly. In addition, if a port
258 which is marked with early_sto 292 which is marked with early_stop has failed to initialize, it will ignore
259 all future connections until t 293 all future connections until this attribute is clear.
260 294
261 What: /sys/bus/usb/devices/.../<hub_ <<
262 Date: June 2023 <<
263 Contact: Roy Luo <royluo@google.com> <<
264 Description: <<
265 Indicates current state of the <<
266 Valid states are: 'not-attache <<
267 'reconnecting', 'unauthenticat <<
268 'configured', and 'suspended'. <<
269 monitor the state change from <<
270 <<
271 What: /sys/bus/usb/devices/.../power 295 What: /sys/bus/usb/devices/.../power/usb2_lpm_l1_timeout
272 Date: May 2013 296 Date: May 2013
273 Contact: Mathias Nyman <mathias.nyman@li 297 Contact: Mathias Nyman <mathias.nyman@linux.intel.com>
274 Description: 298 Description:
275 USB 2.0 devices may support ha 299 USB 2.0 devices may support hardware link power management (LPM)
276 L1 sleep state. The usb2_lpm_l 300 L1 sleep state. The usb2_lpm_l1_timeout attribute allows
277 tuning the timeout for L1 inac 301 tuning the timeout for L1 inactivity timer (LPM timer), e.g.
278 needed inactivity time before 302 needed inactivity time before host requests the device to go to L1 sleep.
279 Useful for power management tu 303 Useful for power management tuning.
280 Supported values are 0 - 65535 304 Supported values are 0 - 65535 microseconds.
281 305
282 What: /sys/bus/usb/devices/.../power 306 What: /sys/bus/usb/devices/.../power/usb2_lpm_besl
283 Date: May 2013 307 Date: May 2013
284 Contact: Mathias Nyman <mathias.nyman@li 308 Contact: Mathias Nyman <mathias.nyman@linux.intel.com>
285 Description: 309 Description:
286 USB 2.0 devices that support h 310 USB 2.0 devices that support hardware link power management (LPM)
287 L1 sleep state now use a best 311 L1 sleep state now use a best effort service latency value (BESL) to
288 indicate the best effort to re 312 indicate the best effort to resumption of service to the device after the
289 initiation of the resume event 313 initiation of the resume event.
290 If the device does not have a 314 If the device does not have a preferred besl value then the host can select
291 one instead. This usb2_lpm_bes 315 one instead. This usb2_lpm_besl attribute allows to tune the host selected besl
292 value in order to tune power s 316 value in order to tune power saving and service latency.
293 317
294 Supported values are 0 - 15. 318 Supported values are 0 - 15.
295 More information on how besl v 319 More information on how besl values map to microseconds can be found in
296 USB 2.0 ECN Errata for Link Po 320 USB 2.0 ECN Errata for Link Power Management, section 4.10)
297 321
298 What: /sys/bus/usb/devices/.../rx_la 322 What: /sys/bus/usb/devices/.../rx_lanes
299 Date: March 2018 323 Date: March 2018
300 Contact: Mathias Nyman <mathias.nyman@li 324 Contact: Mathias Nyman <mathias.nyman@linux.intel.com>
301 Description: 325 Description:
302 Number of rx lanes the device 326 Number of rx lanes the device is using.
303 USB 3.2 adds Dual-lane support 327 USB 3.2 adds Dual-lane support, 2 rx and 2 tx lanes over Type-C.
304 Inter-Chip SSIC devices suppor 328 Inter-Chip SSIC devices support asymmetric lanes up to 4 lanes per
305 direction. Devices before USB 329 direction. Devices before USB 3.2 are single lane (rx_lanes = 1)
306 330
307 What: /sys/bus/usb/devices/.../tx_la 331 What: /sys/bus/usb/devices/.../tx_lanes
308 Date: March 2018 332 Date: March 2018
309 Contact: Mathias Nyman <mathias.nyman@li 333 Contact: Mathias Nyman <mathias.nyman@linux.intel.com>
310 Description: 334 Description:
311 Number of tx lanes the device 335 Number of tx lanes the device is using.
312 USB 3.2 adds Dual-lane support 336 USB 3.2 adds Dual-lane support, 2 rx and 2 tx -lanes over Type-C.
313 Inter-Chip SSIC devices suppor 337 Inter-Chip SSIC devices support asymmetric lanes up to 4 lanes per
314 direction. Devices before USB 338 direction. Devices before USB 3.2 are single lane (tx_lanes = 1)
315 339
316 What: /sys/bus/usb/devices/.../typec <<
317 Date: November 2023 <<
318 Contact: Heikki Krogerus <heikki.krogeru <<
319 Description: <<
320 Symlink to the USB Type-C part <<
321 represents the component that <<
322 Configuration Channel (CC sign <<
323 cables) with the local port. <<
324 <<
325 What: /sys/bus/usb/devices/usbX/bAlt 340 What: /sys/bus/usb/devices/usbX/bAlternateSetting
326 Description: 341 Description:
327 The current interface alternat 342 The current interface alternate setting number, in decimal.
328 343
329 See USB specs for its meaning. 344 See USB specs for its meaning.
330 345
331 What: /sys/bus/usb/devices/usbX/bcdD 346 What: /sys/bus/usb/devices/usbX/bcdDevice
332 Description: 347 Description:
333 The device's release number, i 348 The device's release number, in hexadecimal.
334 349
335 See USB specs for its meaning. 350 See USB specs for its meaning.
336 351
337 What: /sys/bus/usb/devices/usbX/bCon 352 What: /sys/bus/usb/devices/usbX/bConfigurationValue
338 Description: 353 Description:
339 While a USB device typically h 354 While a USB device typically have just one configuration
340 setting, some devices support 355 setting, some devices support multiple configurations.
341 356
342 This value shows the current c 357 This value shows the current configuration, in decimal.
343 358
344 Changing its value will change 359 Changing its value will change the device's configuration
345 to another setting. 360 to another setting.
346 361
347 The number of configurations s 362 The number of configurations supported by a device is at:
348 363
349 /sys/bus/usb/devices/u 364 /sys/bus/usb/devices/usbX/bNumConfigurations
350 365
351 See USB specs for its meaning. 366 See USB specs for its meaning.
352 367
353 What: /sys/bus/usb/devices/usbX/bDev 368 What: /sys/bus/usb/devices/usbX/bDeviceClass
354 Description: 369 Description:
355 Class code of the device, in h 370 Class code of the device, in hexadecimal.
356 371
357 See USB specs for its meaning. 372 See USB specs for its meaning.
358 373
359 What: /sys/bus/usb/devices/usbX/bDev 374 What: /sys/bus/usb/devices/usbX/bDeviceProtocol
360 Description: 375 Description:
361 Protocol code of the device, i 376 Protocol code of the device, in hexadecimal.
362 377
363 See USB specs for its meaning. 378 See USB specs for its meaning.
364 379
365 What: /sys/bus/usb/devices/usbX/bDev 380 What: /sys/bus/usb/devices/usbX/bDeviceSubClass
366 Description: 381 Description:
367 Subclass code of the device, i 382 Subclass code of the device, in hexadecimal.
368 383
369 See USB specs for its meaning. 384 See USB specs for its meaning.
370 385
371 What: /sys/bus/usb/devices/usbX/bInt 386 What: /sys/bus/usb/devices/usbX/bInterfaceClass
372 Description: 387 Description:
373 Class code of the interface, i 388 Class code of the interface, in hexadecimal.
374 389
375 See USB specs for its meaning. 390 See USB specs for its meaning.
376 391
377 What: /sys/bus/usb/devices/usbX/bInt 392 What: /sys/bus/usb/devices/usbX/bInterfaceNumber
378 Description: 393 Description:
379 Interface number, in hexadecim 394 Interface number, in hexadecimal.
380 395
381 See USB specs for its meaning. 396 See USB specs for its meaning.
382 397
383 What: /sys/bus/usb/devices/usbX/bInt 398 What: /sys/bus/usb/devices/usbX/bInterfaceProtocol
384 Description: 399 Description:
385 Protocol code of the interface 400 Protocol code of the interface, in hexadecimal.
386 401
387 See USB specs for its meaning. 402 See USB specs for its meaning.
388 403
389 What: /sys/bus/usb/devices/usbX/bInt 404 What: /sys/bus/usb/devices/usbX/bInterfaceSubClass
390 Description: 405 Description:
391 Subclass code of the interface 406 Subclass code of the interface, in hexadecimal.
392 407
393 See USB specs for its meaning. 408 See USB specs for its meaning.
394 409
395 What: /sys/bus/usb/devices/usbX/bmAt 410 What: /sys/bus/usb/devices/usbX/bmAttributes
396 Description: 411 Description:
397 Attributes of the current conf 412 Attributes of the current configuration, in hexadecimal.
398 413
399 See USB specs for its meaning. 414 See USB specs for its meaning.
400 415
401 What: /sys/bus/usb/devices/usbX/bMax 416 What: /sys/bus/usb/devices/usbX/bMaxPacketSize0
402 Description: 417 Description:
403 Maximum endpoint 0 packet size 418 Maximum endpoint 0 packet size, in decimal.
404 419
405 See USB specs for its meaning. 420 See USB specs for its meaning.
406 421
407 What: /sys/bus/usb/devices/usbX/bMax 422 What: /sys/bus/usb/devices/usbX/bMaxPower
408 Description: 423 Description:
409 Maximum power consumption of t 424 Maximum power consumption of the active configuration of
410 the device, in miliamperes. 425 the device, in miliamperes.
411 426
412 What: /sys/bus/usb/devices/usbX/bNum 427 What: /sys/bus/usb/devices/usbX/bNumConfigurations
413 Description: 428 Description:
414 Number of the possible configu 429 Number of the possible configurations of the device, in
415 decimal. The current configura 430 decimal. The current configuration is controlled via:
416 431
417 /sys/bus/usb/devices/u 432 /sys/bus/usb/devices/usbX/bConfigurationValue
418 433
419 See USB specs for its meaning. 434 See USB specs for its meaning.
420 435
421 What: /sys/bus/usb/devices/usbX/bNum 436 What: /sys/bus/usb/devices/usbX/bNumEndpoints
422 Description: 437 Description:
423 Number of endpoints used on th 438 Number of endpoints used on this interface, in hexadecimal.
424 439
425 See USB specs for its meaning. 440 See USB specs for its meaning.
426 441
427 What: /sys/bus/usb/devices/usbX/bNum 442 What: /sys/bus/usb/devices/usbX/bNumInterfaces
428 Description: 443 Description:
429 Number of interfaces on this d 444 Number of interfaces on this device, in decimal.
430 445
431 What: /sys/bus/usb/devices/usbX/busn 446 What: /sys/bus/usb/devices/usbX/busnum
432 Description: 447 Description:
433 Number of the bus. 448 Number of the bus.
434 449
435 What: /sys/bus/usb/devices/usbX/conf 450 What: /sys/bus/usb/devices/usbX/configuration
436 Description: 451 Description:
437 Contents of the string descrip 452 Contents of the string descriptor associated with the
438 current configuration. It may 453 current configuration. It may include the firmware version
439 of a device and/or its serial 454 of a device and/or its serial number.
440 455
441 What: /sys/bus/usb/devices/usbX/desc 456 What: /sys/bus/usb/devices/usbX/descriptors
442 Description: 457 Description:
443 Contains the interface descrip 458 Contains the interface descriptors, in binary.
444 <<
445 What: /sys/bus/usb/devices/usbX/bos_ <<
446 Date: March 2024 <<
447 Contact: Elbert Mai <code@elbertmai.com> <<
448 Description: <<
449 Binary file containing the cac <<
450 of the device. This consists o <<
451 set of device capability descr <<
452 this file are in bus-endian fo <<
453 request the BOS from a device <<
454 459
455 What: /sys/bus/usb/devices/usbX/idPr 460 What: /sys/bus/usb/devices/usbX/idProduct
456 Description: 461 Description:
457 Product ID, in hexadecimal. 462 Product ID, in hexadecimal.
458 463
459 What: /sys/bus/usb/devices/usbX/idVe 464 What: /sys/bus/usb/devices/usbX/idVendor
460 Description: 465 Description:
461 Vendor ID, in hexadecimal. 466 Vendor ID, in hexadecimal.
462 467
463 What: /sys/bus/usb/devices/usbX/devs 468 What: /sys/bus/usb/devices/usbX/devspec
464 Description: 469 Description:
465 Displays the Device Tree Open 470 Displays the Device Tree Open Firmware node of the interface.
466 471
467 What: /sys/bus/usb/devices/usbX/avoi 472 What: /sys/bus/usb/devices/usbX/avoid_reset_quirk
468 Description: 473 Description:
469 Most devices have this set to 474 Most devices have this set to zero.
470 475
471 If the value is 1, enable a US 476 If the value is 1, enable a USB quirk that prevents this
472 device to use reset. 477 device to use reset.
473 478
474 (read/write) 479 (read/write)
475 480
476 What: /sys/bus/usb/devices/usbX/devn 481 What: /sys/bus/usb/devices/usbX/devnum
477 Description: 482 Description:
478 USB interface device number, i 483 USB interface device number, in decimal.
479 484
480 What: /sys/bus/usb/devices/usbX/devp 485 What: /sys/bus/usb/devices/usbX/devpath
481 Description: 486 Description:
482 String containing the USB inte 487 String containing the USB interface device path.
483 488
484 What: /sys/bus/usb/devices/usbX/manu 489 What: /sys/bus/usb/devices/usbX/manufacturer
485 Description: 490 Description:
486 Vendor specific string contain 491 Vendor specific string containing the name of the
487 manufacturer of the device. 492 manufacturer of the device.
488 493
489 What: /sys/bus/usb/devices/usbX/maxc 494 What: /sys/bus/usb/devices/usbX/maxchild
490 Description: 495 Description:
491 Number of ports of an USB hub 496 Number of ports of an USB hub
492 497
493 What: /sys/bus/usb/devices/usbX/pers 498 What: /sys/bus/usb/devices/usbX/persist
494 Description: 499 Description:
495 Keeps the device even if it ge 500 Keeps the device even if it gets disconnected.
496 501
497 What: /sys/bus/usb/devices/usbX/prod 502 What: /sys/bus/usb/devices/usbX/product
498 Description: 503 Description:
499 Vendor specific string contain 504 Vendor specific string containing the name of the
500 device's product. 505 device's product.
501 506
502 What: /sys/bus/usb/devices/usbX/spee 507 What: /sys/bus/usb/devices/usbX/speed
503 Description: 508 Description:
504 Shows the device's max speed, 509 Shows the device's max speed, according to the USB version,
505 in Mbps. 510 in Mbps.
506 Can be: 511 Can be:
507 512
508 ======= ====== 513 ======= ====================
509 Unknown speed 514 Unknown speed unknown
510 1.5 Low sp 515 1.5 Low speed
511 15 Full s 516 15 Full speed
512 480 High S 517 480 High Speed
513 5000 Super 518 5000 Super Speed
514 10000 Super 519 10000 Super Speed+
515 20000 Super 520 20000 Super Speed+ Gen 2x2
516 ======= ====== 521 ======= ====================
517 522
518 What: /sys/bus/usb/devices/usbX/supp 523 What: /sys/bus/usb/devices/usbX/supports_autosuspend
519 Description: 524 Description:
520 Returns 1 if the device doesn' 525 Returns 1 if the device doesn't support autosuspend.
521 Otherwise, returns 0. 526 Otherwise, returns 0.
522 527
523 What: /sys/bus/usb/devices/usbX/urbn 528 What: /sys/bus/usb/devices/usbX/urbnum
524 Description: 529 Description:
525 Number of URBs submitted for t 530 Number of URBs submitted for the whole device.
526 531
527 What: /sys/bus/usb/devices/usbX/vers 532 What: /sys/bus/usb/devices/usbX/version
528 Description: 533 Description:
529 String containing the USB devi 534 String containing the USB device version, as encoded
530 at the BCD descriptor. 535 at the BCD descriptor.
531 536
532 What: /sys/bus/usb/devices/usbX/powe 537 What: /sys/bus/usb/devices/usbX/power/autosuspend
533 Description: 538 Description:
534 Time in milliseconds for the d 539 Time in milliseconds for the device to autosuspend. If the
535 value is negative, then autosu 540 value is negative, then autosuspend is prevented.
536 541
537 (read/write) 542 (read/write)
538 543
539 What: /sys/bus/usb/devices/usbX/powe 544 What: /sys/bus/usb/devices/usbX/power/active_duration
540 Description: 545 Description:
541 The total time the device has 546 The total time the device has not been suspended.
542 547
543 What: /sys/bus/usb/devices/usbX/powe 548 What: /sys/bus/usb/devices/usbX/power/connected_duration
544 Description: 549 Description:
545 The total time (in msec) that 550 The total time (in msec) that the device has been connected.
546 551
547 What: /sys/bus/usb/devices/usbX/powe 552 What: /sys/bus/usb/devices/usbX/power/level
548 Description: 553 Description:
549 554
550 What: /sys/bus/usb/devices/usbX/ep_< 555 What: /sys/bus/usb/devices/usbX/ep_<N>/bEndpointAddress
551 Description: 556 Description:
552 The address of the endpoint de 557 The address of the endpoint described by this descriptor,
553 in hexadecimal. The endpoint d 558 in hexadecimal. The endpoint direction on this bitmapped field
554 is also shown at: 559 is also shown at:
555 560
556 /sys/bus/usb/devices/u 561 /sys/bus/usb/devices/usbX/ep_<N>/direction
557 562
558 See USB specs for its meaning. 563 See USB specs for its meaning.
559 564
560 What: /sys/bus/usb/devices/usbX/ep_< 565 What: /sys/bus/usb/devices/usbX/ep_<N>/bInterval
561 Description: 566 Description:
562 The interval of the endpoint a 567 The interval of the endpoint as described on its descriptor,
563 in hexadecimal. The actual int 568 in hexadecimal. The actual interval depends on the version
564 of the USB. Also shown in time 569 of the USB. Also shown in time units at
565 /sys/bus/usb/devices/usbX/ep_< 570 /sys/bus/usb/devices/usbX/ep_<N>/interval.
566 571
567 What: /sys/bus/usb/devices/usbX/ep_< 572 What: /sys/bus/usb/devices/usbX/ep_<N>/bLength
568 Description: 573 Description:
569 Number of bytes of the endpoin 574 Number of bytes of the endpoint descriptor, in hexadecimal.
570 575
571 What: /sys/bus/usb/devices/usbX/ep_< 576 What: /sys/bus/usb/devices/usbX/ep_<N>/bmAttributes
572 Description: 577 Description:
573 Attributes which apply to the 578 Attributes which apply to the endpoint as described on its
574 descriptor, in hexadecimal. Th 579 descriptor, in hexadecimal. The endpoint type on this
575 bitmapped field is also shown 580 bitmapped field is also shown at:
576 581
577 /sys/bus/usb/devices/u 582 /sys/bus/usb/devices/usbX/ep_<N>/type
578 583
579 See USB specs for its meaning. 584 See USB specs for its meaning.
580 585
581 What: /sys/bus/usb/devices/usbX/ep_< 586 What: /sys/bus/usb/devices/usbX/ep_<N>/direction
582 Description: 587 Description:
583 Direction of the endpoint. Can 588 Direction of the endpoint. Can be:
584 589
585 - both (on control endpoin 590 - both (on control endpoints)
586 - in 591 - in
587 - out 592 - out
588 593
589 What: /sys/bus/usb/devices/usbX/ep_< 594 What: /sys/bus/usb/devices/usbX/ep_<N>/interval
590 Description: 595 Description:
591 Interval for polling endpoint 596 Interval for polling endpoint for data transfers, in
592 milisseconds or microseconds. 597 milisseconds or microseconds.
593 598
594 What: /sys/bus/usb/devices/usbX/ep_< 599 What: /sys/bus/usb/devices/usbX/ep_<N>/type
595 Description: 600 Description:
596 Descriptor type. Can be: 601 Descriptor type. Can be:
597 602
598 - Control 603 - Control
599 - Isoc 604 - Isoc
600 - Bulk 605 - Bulk
601 - Interrupt 606 - Interrupt
602 - unknown 607 - unknown
603 608
604 What: /sys/bus/usb/devices/usbX/ep_< 609 What: /sys/bus/usb/devices/usbX/ep_<N>/wMaxPacketSize
605 Description: 610 Description:
606 Maximum packet size this endpo 611 Maximum packet size this endpoint is capable of
607 sending or receiving, in hexad 612 sending or receiving, in hexadecimal.
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.