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 <<
136 Date: February 2023 <<
137 Contact: Bastien Nocera <hadess@hadess.n <<
138 Description: <<
139 Some USB devices use a USB rec <<
140 wirelessly with their device u <<
141 attribute allows user-space to <<
142 connected to its receiver dong <<
143 the device to be absent when c <<
144 device's battery, show a heads <<
145 an on-screen keyboard if the o <<
146 turned off. <<
147 This attribute is not to be us <<
148 statuses available in WWAN, WL <<
149 If the device does not use a r <<
150 device, then this attribute wi <<
151 <<
152 What: /sys/bus/usb/devices/.../<hub_ 169 What: /sys/bus/usb/devices/.../<hub_interface>/port<X>
153 Date: August 2012 170 Date: August 2012
154 Contact: Lan Tianyu <tianyu.lan@intel.co 171 Contact: Lan Tianyu <tianyu.lan@intel.com>
155 Description: 172 Description:
156 The /sys/bus/usb/devices/.../< 173 The /sys/bus/usb/devices/.../<hub_interface>/port<X>
157 is usb port device's sysfs dir 174 is usb port device's sysfs directory.
158 175
159 What: /sys/bus/usb/devices/.../<hub_ 176 What: /sys/bus/usb/devices/.../<hub_interface>/port<X>/connect_type
160 Date: January 2013 177 Date: January 2013
161 Contact: Lan Tianyu <tianyu.lan@intel.co 178 Contact: Lan Tianyu <tianyu.lan@intel.com>
162 Description: 179 Description:
163 Some platforms provide usb por 180 Some platforms provide usb port connect types through ACPI.
164 This attribute is to expose th 181 This attribute is to expose these information to user space.
165 The file will read "hotplug", 182 The file will read "hotplug", "hardwired" and "not used" if the
166 information is available, and 183 information is available, and "unknown" otherwise.
167 184
168 What: /sys/bus/usb/devices/.../<hub_ 185 What: /sys/bus/usb/devices/.../<hub_interface>/port<X>/location
169 Date: October 2018 186 Date: October 2018
170 Contact: Bjørn Mork <bjorn@mork.no> 187 Contact: Bjørn Mork <bjorn@mork.no>
171 Description: 188 Description:
172 Some platforms provide usb por 189 Some platforms provide usb port physical location through
173 firmware. This is used by the 190 firmware. This is used by the kernel to pair up logical ports
174 mapping to the same physical c 191 mapping to the same physical connector. The attribute exposes the
175 raw location value as a hex in 192 raw location value as a hex integer.
176 193
177 194
178 What: /sys/bus/usb/devices/.../<hub_ 195 What: /sys/bus/usb/devices/.../<hub_interface>/port<X>/quirks
179 Date: May 2018 196 Date: May 2018
180 Contact: Nicolas Boichat <drinkcat@chrom 197 Contact: Nicolas Boichat <drinkcat@chromium.org>
181 Description: 198 Description:
182 In some cases, we care about t 199 In some cases, we care about time-to-active for devices
183 connected on a specific port ( 200 connected on a specific port (e.g. non-standard USB port like
184 pogo pins), where the device t 201 pogo pins), where the device to be connected is known in
185 advance, and behaves well acco 202 advance, and behaves well according to the specification.
186 This attribute is a bit-field 203 This attribute is a bit-field that controls the behavior of
187 a specific port: 204 a specific port:
188 205
189 - Bit 0 of this field selects 206 - Bit 0 of this field selects the "old" enumeration scheme,
190 as it is considerably faste 207 as it is considerably faster (it only causes one USB reset
191 instead of 2). 208 instead of 2).
192 209
193 The old enumeration scheme 210 The old enumeration scheme can also be selected globally
194 using /sys/module/usbcore/p 211 using /sys/module/usbcore/parameters/old_scheme_first, but
195 it is often not desirable a 212 it is often not desirable as the new scheme was introduced to
196 increase compatibility with 213 increase compatibility with more devices.
197 - Bit 1 reduces TRSTRCY to th 214 - Bit 1 reduces TRSTRCY to the 10 ms that are required by the
198 USB 2.0 specification, inst 215 USB 2.0 specification, instead of the 50 ms that are normally
199 used to help make enumerati 216 used to help make enumeration work better on some high speed
200 devices. 217 devices.
201 218
202 What: /sys/bus/usb/devices/.../<hub_ 219 What: /sys/bus/usb/devices/.../<hub_interface>/port<X>/over_current_count
203 Date: February 2018 220 Date: February 2018
204 Contact: Richard Leitner <richard.leitne 221 Contact: Richard Leitner <richard.leitner@skidata.com>
205 Description: 222 Description:
206 Most hubs are able to detect o 223 Most hubs are able to detect over-current situations on their
207 ports and report them to the k 224 ports and report them to the kernel. This attribute is to expose
208 the number of over-current sit 225 the number of over-current situation occurred on a specific port
209 to user space. This file will 226 to user space. This file will contain an unsigned 32 bit value
210 which wraps to 0 after its max 227 which wraps to 0 after its maximum is reached. This file supports
211 poll() for monitoring changes 228 poll() for monitoring changes to this value in user space.
212 229
213 Any time this value changes th 230 Any time this value changes the corresponding hub device will send a
214 udev event with the following 231 udev event with the following attributes::
215 232
216 OVER_CURRENT_PORT=/sys/bus/u 233 OVER_CURRENT_PORT=/sys/bus/usb/devices/.../<hub_interface>/port<X>
217 OVER_CURRENT_COUNT=[current 234 OVER_CURRENT_COUNT=[current value of this sysfs attribute]
218 235
219 What: /sys/bus/usb/devices/.../<hub_ 236 What: /sys/bus/usb/devices/.../<hub_interface>/port<X>/usb3_lpm_permit
220 Date: November 2015 237 Date: November 2015
221 Contact: Lu Baolu <baolu.lu@linux.intel. 238 Contact: Lu Baolu <baolu.lu@linux.intel.com>
222 Description: 239 Description:
223 Some USB3.0 devices are not fr 240 Some USB3.0 devices are not friendly to USB3 LPM. usb3_lpm_permit
224 attribute allows enabling/disa 241 attribute allows enabling/disabling usb3 lpm of a port. It takes
225 effect both before and after a 242 effect both before and after a usb device is enumerated. Supported
226 values are "0" if both u1 and 243 values are "0" if both u1 and u2 are NOT permitted, "u1" if only u1
227 is permitted, "u2" if only u2 244 is permitted, "u2" if only u2 is permitted, "u1_u2" if both u1 and
228 u2 are permitted. 245 u2 are permitted.
229 246
230 What: /sys/bus/usb/devices/.../<hub_ 247 What: /sys/bus/usb/devices/.../<hub_interface>/port<X>/connector
231 Date: December 2021 248 Date: December 2021
232 Contact: Heikki Krogerus <heikki.krogeru 249 Contact: Heikki Krogerus <heikki.krogerus@linux.intel.com>
233 Description: 250 Description:
234 Link to the USB Type-C connect 251 Link to the USB Type-C connector when available. This link is
235 only created when USB Type-C C 252 only created when USB Type-C Connector Class is enabled, and
236 only if the system firmware is 253 only if the system firmware is capable of describing the
237 connection between a port and 254 connection between a port and its connector.
238 255
239 What: /sys/bus/usb/devices/.../<hub_ <<
240 Date: June 2022 <<
241 Contact: Michael Grzeschik <m.grzeschik@ <<
242 Description: <<
243 This file controls the state o <<
244 Vbus power output (but only on <<
245 power switching -- most hubs d <<
246 a port is disabled, the port i <<
247 attached to the port will not <<
248 or enumerated. <<
249 <<
250 What: /sys/bus/usb/devices/.../<hub_ <<
251 Date: Sep 2022 <<
252 Contact: Ray Chi <raychi@google.com> <<
253 Description: <<
254 Some USB hosts have some watch <<
255 may enter ramdump if it takes <<
256 This attribute allows each por <<
257 port initialization will be fa <<
258 which is marked with early_sto <<
259 all future connections until t <<
260 <<
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 256 What: /sys/bus/usb/devices/.../power/usb2_lpm_l1_timeout
272 Date: May 2013 257 Date: May 2013
273 Contact: Mathias Nyman <mathias.nyman@li 258 Contact: Mathias Nyman <mathias.nyman@linux.intel.com>
274 Description: 259 Description:
275 USB 2.0 devices may support ha 260 USB 2.0 devices may support hardware link power management (LPM)
276 L1 sleep state. The usb2_lpm_l 261 L1 sleep state. The usb2_lpm_l1_timeout attribute allows
277 tuning the timeout for L1 inac 262 tuning the timeout for L1 inactivity timer (LPM timer), e.g.
278 needed inactivity time before 263 needed inactivity time before host requests the device to go to L1 sleep.
279 Useful for power management tu 264 Useful for power management tuning.
280 Supported values are 0 - 65535 265 Supported values are 0 - 65535 microseconds.
281 266
282 What: /sys/bus/usb/devices/.../power 267 What: /sys/bus/usb/devices/.../power/usb2_lpm_besl
283 Date: May 2013 268 Date: May 2013
284 Contact: Mathias Nyman <mathias.nyman@li 269 Contact: Mathias Nyman <mathias.nyman@linux.intel.com>
285 Description: 270 Description:
286 USB 2.0 devices that support h 271 USB 2.0 devices that support hardware link power management (LPM)
287 L1 sleep state now use a best 272 L1 sleep state now use a best effort service latency value (BESL) to
288 indicate the best effort to re 273 indicate the best effort to resumption of service to the device after the
289 initiation of the resume event 274 initiation of the resume event.
290 If the device does not have a 275 If the device does not have a preferred besl value then the host can select
291 one instead. This usb2_lpm_bes 276 one instead. This usb2_lpm_besl attribute allows to tune the host selected besl
292 value in order to tune power s 277 value in order to tune power saving and service latency.
293 278
294 Supported values are 0 - 15. 279 Supported values are 0 - 15.
295 More information on how besl v 280 More information on how besl values map to microseconds can be found in
296 USB 2.0 ECN Errata for Link Po 281 USB 2.0 ECN Errata for Link Power Management, section 4.10)
297 282
298 What: /sys/bus/usb/devices/.../rx_la 283 What: /sys/bus/usb/devices/.../rx_lanes
299 Date: March 2018 284 Date: March 2018
300 Contact: Mathias Nyman <mathias.nyman@li 285 Contact: Mathias Nyman <mathias.nyman@linux.intel.com>
301 Description: 286 Description:
302 Number of rx lanes the device 287 Number of rx lanes the device is using.
303 USB 3.2 adds Dual-lane support 288 USB 3.2 adds Dual-lane support, 2 rx and 2 tx lanes over Type-C.
304 Inter-Chip SSIC devices suppor 289 Inter-Chip SSIC devices support asymmetric lanes up to 4 lanes per
305 direction. Devices before USB 290 direction. Devices before USB 3.2 are single lane (rx_lanes = 1)
306 291
307 What: /sys/bus/usb/devices/.../tx_la 292 What: /sys/bus/usb/devices/.../tx_lanes
308 Date: March 2018 293 Date: March 2018
309 Contact: Mathias Nyman <mathias.nyman@li 294 Contact: Mathias Nyman <mathias.nyman@linux.intel.com>
310 Description: 295 Description:
311 Number of tx lanes the device 296 Number of tx lanes the device is using.
312 USB 3.2 adds Dual-lane support 297 USB 3.2 adds Dual-lane support, 2 rx and 2 tx -lanes over Type-C.
313 Inter-Chip SSIC devices suppor 298 Inter-Chip SSIC devices support asymmetric lanes up to 4 lanes per
314 direction. Devices before USB 299 direction. Devices before USB 3.2 are single lane (tx_lanes = 1)
315 300
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 301 What: /sys/bus/usb/devices/usbX/bAlternateSetting
326 Description: 302 Description:
327 The current interface alternat 303 The current interface alternate setting number, in decimal.
328 304
329 See USB specs for its meaning. 305 See USB specs for its meaning.
330 306
331 What: /sys/bus/usb/devices/usbX/bcdD 307 What: /sys/bus/usb/devices/usbX/bcdDevice
332 Description: 308 Description:
333 The device's release number, i 309 The device's release number, in hexadecimal.
334 310
335 See USB specs for its meaning. 311 See USB specs for its meaning.
336 312
337 What: /sys/bus/usb/devices/usbX/bCon 313 What: /sys/bus/usb/devices/usbX/bConfigurationValue
338 Description: 314 Description:
339 While a USB device typically h 315 While a USB device typically have just one configuration
340 setting, some devices support 316 setting, some devices support multiple configurations.
341 317
342 This value shows the current c 318 This value shows the current configuration, in decimal.
343 319
344 Changing its value will change 320 Changing its value will change the device's configuration
345 to another setting. 321 to another setting.
346 322
347 The number of configurations s 323 The number of configurations supported by a device is at:
348 324
349 /sys/bus/usb/devices/u 325 /sys/bus/usb/devices/usbX/bNumConfigurations
350 326
351 See USB specs for its meaning. 327 See USB specs for its meaning.
352 328
353 What: /sys/bus/usb/devices/usbX/bDev 329 What: /sys/bus/usb/devices/usbX/bDeviceClass
354 Description: 330 Description:
355 Class code of the device, in h 331 Class code of the device, in hexadecimal.
356 332
357 See USB specs for its meaning. 333 See USB specs for its meaning.
358 334
359 What: /sys/bus/usb/devices/usbX/bDev 335 What: /sys/bus/usb/devices/usbX/bDeviceProtocol
360 Description: 336 Description:
361 Protocol code of the device, i 337 Protocol code of the device, in hexadecimal.
362 338
363 See USB specs for its meaning. 339 See USB specs for its meaning.
364 340
365 What: /sys/bus/usb/devices/usbX/bDev 341 What: /sys/bus/usb/devices/usbX/bDeviceSubClass
366 Description: 342 Description:
367 Subclass code of the device, i 343 Subclass code of the device, in hexadecimal.
368 344
369 See USB specs for its meaning. 345 See USB specs for its meaning.
370 346
371 What: /sys/bus/usb/devices/usbX/bInt 347 What: /sys/bus/usb/devices/usbX/bInterfaceClass
372 Description: 348 Description:
373 Class code of the interface, i 349 Class code of the interface, in hexadecimal.
374 350
375 See USB specs for its meaning. 351 See USB specs for its meaning.
376 352
377 What: /sys/bus/usb/devices/usbX/bInt 353 What: /sys/bus/usb/devices/usbX/bInterfaceNumber
378 Description: 354 Description:
379 Interface number, in hexadecim 355 Interface number, in hexadecimal.
380 356
381 See USB specs for its meaning. 357 See USB specs for its meaning.
382 358
383 What: /sys/bus/usb/devices/usbX/bInt 359 What: /sys/bus/usb/devices/usbX/bInterfaceProtocol
384 Description: 360 Description:
385 Protocol code of the interface 361 Protocol code of the interface, in hexadecimal.
386 362
387 See USB specs for its meaning. 363 See USB specs for its meaning.
388 364
389 What: /sys/bus/usb/devices/usbX/bInt 365 What: /sys/bus/usb/devices/usbX/bInterfaceSubClass
390 Description: 366 Description:
391 Subclass code of the interface 367 Subclass code of the interface, in hexadecimal.
392 368
393 See USB specs for its meaning. 369 See USB specs for its meaning.
394 370
395 What: /sys/bus/usb/devices/usbX/bmAt 371 What: /sys/bus/usb/devices/usbX/bmAttributes
396 Description: 372 Description:
397 Attributes of the current conf 373 Attributes of the current configuration, in hexadecimal.
398 374
399 See USB specs for its meaning. 375 See USB specs for its meaning.
400 376
401 What: /sys/bus/usb/devices/usbX/bMax 377 What: /sys/bus/usb/devices/usbX/bMaxPacketSize0
402 Description: 378 Description:
403 Maximum endpoint 0 packet size 379 Maximum endpoint 0 packet size, in decimal.
404 380
405 See USB specs for its meaning. 381 See USB specs for its meaning.
406 382
407 What: /sys/bus/usb/devices/usbX/bMax 383 What: /sys/bus/usb/devices/usbX/bMaxPower
408 Description: 384 Description:
409 Maximum power consumption of t 385 Maximum power consumption of the active configuration of
410 the device, in miliamperes. 386 the device, in miliamperes.
411 387
412 What: /sys/bus/usb/devices/usbX/bNum 388 What: /sys/bus/usb/devices/usbX/bNumConfigurations
413 Description: 389 Description:
414 Number of the possible configu 390 Number of the possible configurations of the device, in
415 decimal. The current configura 391 decimal. The current configuration is controlled via:
416 392
417 /sys/bus/usb/devices/u 393 /sys/bus/usb/devices/usbX/bConfigurationValue
418 394
419 See USB specs for its meaning. 395 See USB specs for its meaning.
420 396
421 What: /sys/bus/usb/devices/usbX/bNum 397 What: /sys/bus/usb/devices/usbX/bNumEndpoints
422 Description: 398 Description:
423 Number of endpoints used on th 399 Number of endpoints used on this interface, in hexadecimal.
424 400
425 See USB specs for its meaning. 401 See USB specs for its meaning.
426 402
427 What: /sys/bus/usb/devices/usbX/bNum 403 What: /sys/bus/usb/devices/usbX/bNumInterfaces
428 Description: 404 Description:
429 Number of interfaces on this d 405 Number of interfaces on this device, in decimal.
430 406
431 What: /sys/bus/usb/devices/usbX/busn 407 What: /sys/bus/usb/devices/usbX/busnum
432 Description: 408 Description:
433 Number of the bus. 409 Number of the bus.
434 410
435 What: /sys/bus/usb/devices/usbX/conf 411 What: /sys/bus/usb/devices/usbX/configuration
436 Description: 412 Description:
437 Contents of the string descrip 413 Contents of the string descriptor associated with the
438 current configuration. It may 414 current configuration. It may include the firmware version
439 of a device and/or its serial 415 of a device and/or its serial number.
440 416
441 What: /sys/bus/usb/devices/usbX/desc 417 What: /sys/bus/usb/devices/usbX/descriptors
442 Description: 418 Description:
443 Contains the interface descrip 419 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 <<
454 420
455 What: /sys/bus/usb/devices/usbX/idPr 421 What: /sys/bus/usb/devices/usbX/idProduct
456 Description: 422 Description:
457 Product ID, in hexadecimal. 423 Product ID, in hexadecimal.
458 424
459 What: /sys/bus/usb/devices/usbX/idVe 425 What: /sys/bus/usb/devices/usbX/idVendor
460 Description: 426 Description:
461 Vendor ID, in hexadecimal. 427 Vendor ID, in hexadecimal.
462 428
463 What: /sys/bus/usb/devices/usbX/devs 429 What: /sys/bus/usb/devices/usbX/devspec
464 Description: 430 Description:
465 Displays the Device Tree Open 431 Displays the Device Tree Open Firmware node of the interface.
466 432
467 What: /sys/bus/usb/devices/usbX/avoi 433 What: /sys/bus/usb/devices/usbX/avoid_reset_quirk
468 Description: 434 Description:
469 Most devices have this set to 435 Most devices have this set to zero.
470 436
471 If the value is 1, enable a US 437 If the value is 1, enable a USB quirk that prevents this
472 device to use reset. 438 device to use reset.
473 439
474 (read/write) 440 (read/write)
475 441
476 What: /sys/bus/usb/devices/usbX/devn 442 What: /sys/bus/usb/devices/usbX/devnum
477 Description: 443 Description:
478 USB interface device number, i 444 USB interface device number, in decimal.
479 445
480 What: /sys/bus/usb/devices/usbX/devp 446 What: /sys/bus/usb/devices/usbX/devpath
481 Description: 447 Description:
482 String containing the USB inte 448 String containing the USB interface device path.
483 449
484 What: /sys/bus/usb/devices/usbX/manu 450 What: /sys/bus/usb/devices/usbX/manufacturer
485 Description: 451 Description:
486 Vendor specific string contain 452 Vendor specific string containing the name of the
487 manufacturer of the device. 453 manufacturer of the device.
488 454
489 What: /sys/bus/usb/devices/usbX/maxc 455 What: /sys/bus/usb/devices/usbX/maxchild
490 Description: 456 Description:
491 Number of ports of an USB hub 457 Number of ports of an USB hub
492 458
493 What: /sys/bus/usb/devices/usbX/pers 459 What: /sys/bus/usb/devices/usbX/persist
494 Description: 460 Description:
495 Keeps the device even if it ge 461 Keeps the device even if it gets disconnected.
496 462
497 What: /sys/bus/usb/devices/usbX/prod 463 What: /sys/bus/usb/devices/usbX/product
498 Description: 464 Description:
499 Vendor specific string contain 465 Vendor specific string containing the name of the
500 device's product. 466 device's product.
501 467
502 What: /sys/bus/usb/devices/usbX/spee 468 What: /sys/bus/usb/devices/usbX/speed
503 Description: 469 Description:
504 Shows the device's max speed, 470 Shows the device's max speed, according to the USB version,
505 in Mbps. 471 in Mbps.
506 Can be: 472 Can be:
507 473
508 ======= ====== 474 ======= ====================
509 Unknown speed 475 Unknown speed unknown
510 1.5 Low sp 476 1.5 Low speed
511 15 Full s 477 15 Full speed
512 480 High S 478 480 High Speed
513 5000 Super 479 5000 Super Speed
514 10000 Super 480 10000 Super Speed+
515 20000 Super 481 20000 Super Speed+ Gen 2x2
516 ======= ====== 482 ======= ====================
517 483
518 What: /sys/bus/usb/devices/usbX/supp 484 What: /sys/bus/usb/devices/usbX/supports_autosuspend
519 Description: 485 Description:
520 Returns 1 if the device doesn' 486 Returns 1 if the device doesn't support autosuspend.
521 Otherwise, returns 0. 487 Otherwise, returns 0.
522 488
523 What: /sys/bus/usb/devices/usbX/urbn 489 What: /sys/bus/usb/devices/usbX/urbnum
524 Description: 490 Description:
525 Number of URBs submitted for t 491 Number of URBs submitted for the whole device.
526 492
527 What: /sys/bus/usb/devices/usbX/vers 493 What: /sys/bus/usb/devices/usbX/version
528 Description: 494 Description:
529 String containing the USB devi 495 String containing the USB device version, as encoded
530 at the BCD descriptor. 496 at the BCD descriptor.
531 497
532 What: /sys/bus/usb/devices/usbX/powe 498 What: /sys/bus/usb/devices/usbX/power/autosuspend
533 Description: 499 Description:
534 Time in milliseconds for the d 500 Time in milliseconds for the device to autosuspend. If the
535 value is negative, then autosu 501 value is negative, then autosuspend is prevented.
536 502
537 (read/write) 503 (read/write)
538 504
539 What: /sys/bus/usb/devices/usbX/powe 505 What: /sys/bus/usb/devices/usbX/power/active_duration
540 Description: 506 Description:
541 The total time the device has 507 The total time the device has not been suspended.
542 508
543 What: /sys/bus/usb/devices/usbX/powe 509 What: /sys/bus/usb/devices/usbX/power/connected_duration
544 Description: 510 Description:
545 The total time (in msec) that 511 The total time (in msec) that the device has been connected.
546 512
547 What: /sys/bus/usb/devices/usbX/powe 513 What: /sys/bus/usb/devices/usbX/power/level
548 Description: 514 Description:
549 515
550 What: /sys/bus/usb/devices/usbX/ep_< 516 What: /sys/bus/usb/devices/usbX/ep_<N>/bEndpointAddress
551 Description: 517 Description:
552 The address of the endpoint de 518 The address of the endpoint described by this descriptor,
553 in hexadecimal. The endpoint d 519 in hexadecimal. The endpoint direction on this bitmapped field
554 is also shown at: 520 is also shown at:
555 521
556 /sys/bus/usb/devices/u 522 /sys/bus/usb/devices/usbX/ep_<N>/direction
557 523
558 See USB specs for its meaning. 524 See USB specs for its meaning.
559 525
560 What: /sys/bus/usb/devices/usbX/ep_< 526 What: /sys/bus/usb/devices/usbX/ep_<N>/bInterval
561 Description: 527 Description:
562 The interval of the endpoint a 528 The interval of the endpoint as described on its descriptor,
563 in hexadecimal. The actual int 529 in hexadecimal. The actual interval depends on the version
564 of the USB. Also shown in time 530 of the USB. Also shown in time units at
565 /sys/bus/usb/devices/usbX/ep_< 531 /sys/bus/usb/devices/usbX/ep_<N>/interval.
566 532
567 What: /sys/bus/usb/devices/usbX/ep_< 533 What: /sys/bus/usb/devices/usbX/ep_<N>/bLength
568 Description: 534 Description:
569 Number of bytes of the endpoin 535 Number of bytes of the endpoint descriptor, in hexadecimal.
570 536
571 What: /sys/bus/usb/devices/usbX/ep_< 537 What: /sys/bus/usb/devices/usbX/ep_<N>/bmAttributes
572 Description: 538 Description:
573 Attributes which apply to the 539 Attributes which apply to the endpoint as described on its
574 descriptor, in hexadecimal. Th 540 descriptor, in hexadecimal. The endpoint type on this
575 bitmapped field is also shown 541 bitmapped field is also shown at:
576 542
577 /sys/bus/usb/devices/u 543 /sys/bus/usb/devices/usbX/ep_<N>/type
578 544
579 See USB specs for its meaning. 545 See USB specs for its meaning.
580 546
581 What: /sys/bus/usb/devices/usbX/ep_< 547 What: /sys/bus/usb/devices/usbX/ep_<N>/direction
582 Description: 548 Description:
583 Direction of the endpoint. Can 549 Direction of the endpoint. Can be:
584 550
585 - both (on control endpoin 551 - both (on control endpoints)
586 - in 552 - in
587 - out 553 - out
588 554
589 What: /sys/bus/usb/devices/usbX/ep_< 555 What: /sys/bus/usb/devices/usbX/ep_<N>/interval
590 Description: 556 Description:
591 Interval for polling endpoint 557 Interval for polling endpoint for data transfers, in
592 milisseconds or microseconds. 558 milisseconds or microseconds.
593 559
594 What: /sys/bus/usb/devices/usbX/ep_< 560 What: /sys/bus/usb/devices/usbX/ep_<N>/type
595 Description: 561 Description:
596 Descriptor type. Can be: 562 Descriptor type. Can be:
597 563
598 - Control 564 - Control
599 - Isoc 565 - Isoc
600 - Bulk 566 - Bulk
601 - Interrupt 567 - Interrupt
602 - unknown 568 - unknown
603 569
604 What: /sys/bus/usb/devices/usbX/ep_< 570 What: /sys/bus/usb/devices/usbX/ep_<N>/wMaxPacketSize
605 Description: 571 Description:
606 Maximum packet size this endpo 572 Maximum packet size this endpoint is capable of
607 sending or receiving, in hexad 573 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.