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 What: /sys/bus/usb/drivers/.../new_i 31 What: /sys/bus/usb/drivers/.../new_id
32 Date: October 2011 32 Date: October 2011
33 Contact: linux-usb@vger.kernel.org 33 Contact: linux-usb@vger.kernel.org
34 Description: 34 Description:
35 Writing a device ID to this fi 35 Writing a device ID to this file will attempt to
36 dynamically add a new device I 36 dynamically add a new device ID to a USB device driver.
37 This may allow the driver to s 37 This may allow the driver to support more hardware than
38 was included in the driver's s 38 was included in the driver's static device ID support
39 table at compile time. The for 39 table at compile time. The format for the device ID is:
40 idVendor idProduct bInterfaceC 40 idVendor idProduct bInterfaceClass RefIdVendor RefIdProduct
41 The vendor ID and device ID fi 41 The vendor ID and device ID fields are required, the
42 rest is optional. The `Ref*` t 42 rest is optional. The `Ref*` tuple can be used to tell the
43 driver to use the same driver_ 43 driver to use the same driver_data for the new device as
44 it is used for the reference d 44 it is used for the reference device.
45 Upon successfully adding an ID 45 Upon successfully adding an ID, the driver will probe
46 for the device and attempt to 46 for the device and attempt to bind to it. For example::
47 47
48 # echo "8086 10f5" > /sys/bu 48 # echo "8086 10f5" > /sys/bus/usb/drivers/foo/new_id
49 49
50 Here add a new device (0458:70 50 Here add a new device (0458:7045) using driver_data from
51 an already supported device (0 51 an already supported device (0458:704c)::
52 52
53 # echo "0458 7045 0 0458 704 53 # echo "0458 7045 0 0458 704c" > /sys/bus/usb/drivers/foo/new_id
54 54
55 Reading from this file will li 55 Reading from this file will list all dynamically added
56 device IDs in the same format, 56 device IDs in the same format, with one entry per
57 line. For example:: 57 line. For example::
58 58
59 # cat /sys/bus/usb/drivers/f 59 # cat /sys/bus/usb/drivers/foo/new_id
60 8086 10f5 60 8086 10f5
61 dead beef 06 61 dead beef 06
62 f00d cafe 62 f00d cafe
63 63
64 The list will be truncated at 64 The list will be truncated at PAGE_SIZE bytes due to
65 sysfs restrictions. 65 sysfs restrictions.
66 66
67 What: /sys/bus/usb-serial/drivers/.. 67 What: /sys/bus/usb-serial/drivers/.../new_id
68 Date: October 2011 68 Date: October 2011
69 Contact: linux-usb@vger.kernel.org 69 Contact: linux-usb@vger.kernel.org
70 Description: 70 Description:
71 For serial USB drivers, this a 71 For serial USB drivers, this attribute appears under the
72 extra bus folder "usb-serial" 72 extra bus folder "usb-serial" in sysfs; apart from that
73 difference, all descriptions f 73 difference, all descriptions from the entry
74 "/sys/bus/usb/drivers/.../new_ 74 "/sys/bus/usb/drivers/.../new_id" apply.
75 75
76 What: /sys/bus/usb/drivers/.../remov 76 What: /sys/bus/usb/drivers/.../remove_id
77 Date: November 2009 77 Date: November 2009
78 Contact: CHENG Renquan <rqcheng@smu.edu. 78 Contact: CHENG Renquan <rqcheng@smu.edu.sg>
79 Description: 79 Description:
80 Writing a device ID to this fi 80 Writing a device ID to this file will remove an ID
81 that was dynamically added via 81 that was dynamically added via the new_id sysfs entry.
82 The format for the device ID i 82 The format for the device ID is:
83 idVendor idProduct. After 83 idVendor idProduct. After successfully
84 removing an ID, the driver wil 84 removing an ID, the driver will no longer support the
85 device. This is useful to ens 85 device. This is useful to ensure auto probing won't
86 match the driver to the device 86 match the driver to the device. For example:
87 # echo "046d c315" > /sys/bus/ 87 # echo "046d c315" > /sys/bus/usb/drivers/foo/remove_id
88 88
89 Reading from this file will li 89 Reading from this file will list the dynamically added
90 device IDs, exactly like readi 90 device IDs, exactly like reading from the entry
91 "/sys/bus/usb/drivers/.../new_ 91 "/sys/bus/usb/drivers/.../new_id"
92 92
93 What: /sys/bus/usb/devices/.../power 93 What: /sys/bus/usb/devices/.../power/usb2_hardware_lpm
94 Date: September 2011 94 Date: September 2011
95 Contact: Andiry Xu <andiry.xu@amd.com> 95 Contact: Andiry Xu <andiry.xu@amd.com>
96 Description: 96 Description:
97 If CONFIG_PM is set and a USB 97 If CONFIG_PM is set and a USB 2.0 lpm-capable device is plugged
98 in to a xHCI host which suppor 98 in to a xHCI host which support link PM, it will perform a LPM
99 test; if the test is passed an 99 test; if the test is passed and host supports USB2 hardware LPM
100 (xHCI 1.0 feature), USB2 hardw 100 (xHCI 1.0 feature), USB2 hardware LPM will be enabled for the
101 device and the USB device dire 101 device and the USB device directory will contain a file named
102 power/usb2_hardware_lpm. The 102 power/usb2_hardware_lpm. The file holds a string value (enable
103 or disable) indicating whether 103 or disable) indicating whether or not USB2 hardware LPM is
104 enabled for the device. Develo 104 enabled for the device. Developer can write y/Y/1 or n/N/0 to
105 the file to enable/disable the 105 the file to enable/disable the feature.
106 106
107 What: /sys/bus/usb/devices/.../power 107 What: /sys/bus/usb/devices/.../power/usb3_hardware_lpm_u1
108 /sys/bus/usb/devices/.../power 108 /sys/bus/usb/devices/.../power/usb3_hardware_lpm_u2
109 Date: November 2015 109 Date: November 2015
110 Contact: Kevin Strasser <kevin.strasser@ 110 Contact: Kevin Strasser <kevin.strasser@linux.intel.com>
111 Lu Baolu <baolu.lu@linux.intel. 111 Lu Baolu <baolu.lu@linux.intel.com>
112 Description: 112 Description:
113 If CONFIG_PM is set and a USB 113 If CONFIG_PM is set and a USB 3.0 lpm-capable device is plugged
114 in to a xHCI host which suppor 114 in to a xHCI host which supports link PM, it will check if U1
115 and U2 exit latencies have bee 115 and U2 exit latencies have been set in the BOS descriptor; if
116 the check is passed and the ho 116 the check is passed and the host supports USB3 hardware LPM,
117 USB3 hardware LPM will be enab 117 USB3 hardware LPM will be enabled for the device and the USB
118 device directory will contain 118 device directory will contain two files named
119 power/usb3_hardware_lpm_u1 and 119 power/usb3_hardware_lpm_u1 and power/usb3_hardware_lpm_u2. These
120 files hold a string value (ena 120 files hold a string value (enable or disable) indicating whether
121 or not USB3 hardware LPM U1 or 121 or not USB3 hardware LPM U1 or U2 is enabled for the device.
122 122
123 What: /sys/bus/usb/devices/.../ltm_c 123 What: /sys/bus/usb/devices/.../ltm_capable
124 Date: July 2012 124 Date: July 2012
125 Contact: Sarah Sharp <sarah.a.sharp@linu 125 Contact: Sarah Sharp <sarah.a.sharp@linux.intel.com>
126 Description: 126 Description:
127 USB 3.0 devices may optionally 127 USB 3.0 devices may optionally support Latency Tolerance
128 Messaging (LTM). They indicat 128 Messaging (LTM). They indicate their support by setting a bit
129 in the bmAttributes field of t 129 in the bmAttributes field of their SuperSpeed BOS descriptors.
130 If that bit is set for the dev 130 If that bit is set for the device, ltm_capable will read "yes".
131 If the device doesn't support 131 If the device doesn't support LTM, the file will read "no".
132 The file will be present for a 132 The file will be present for all speeds of USB devices, and will
133 always read "no" for USB 1.1 a 133 always read "no" for USB 1.1 and USB 2.0 devices.
134 134
135 What: /sys/bus/usb/devices/<INTERFAC 135 What: /sys/bus/usb/devices/<INTERFACE>/wireless_status
136 Date: February 2023 136 Date: February 2023
137 Contact: Bastien Nocera <hadess@hadess.n 137 Contact: Bastien Nocera <hadess@hadess.net>
138 Description: 138 Description:
139 Some USB devices use a USB rec 139 Some USB devices use a USB receiver dongle to communicate
140 wirelessly with their device u 140 wirelessly with their device using proprietary protocols. This
141 attribute allows user-space to 141 attribute allows user-space to know whether the device is
142 connected to its receiver dong 142 connected to its receiver dongle, and, for example, consider
143 the device to be absent when c 143 the device to be absent when choosing whether to show the
144 device's battery, show a heads 144 device's battery, show a headset in a list of outputs, or show
145 an on-screen keyboard if the o 145 an on-screen keyboard if the only wireless keyboard is
146 turned off. 146 turned off.
147 This attribute is not to be us 147 This attribute is not to be used to replace protocol specific
148 statuses available in WWAN, WL 148 statuses available in WWAN, WLAN/Wi-Fi, Bluetooth, etc.
149 If the device does not use a r 149 If the device does not use a receiver dongle with a wireless
150 device, then this attribute wi 150 device, then this attribute will not exist.
151 151
152 What: /sys/bus/usb/devices/.../<hub_ 152 What: /sys/bus/usb/devices/.../<hub_interface>/port<X>
153 Date: August 2012 153 Date: August 2012
154 Contact: Lan Tianyu <tianyu.lan@intel.co 154 Contact: Lan Tianyu <tianyu.lan@intel.com>
155 Description: 155 Description:
156 The /sys/bus/usb/devices/.../< 156 The /sys/bus/usb/devices/.../<hub_interface>/port<X>
157 is usb port device's sysfs dir 157 is usb port device's sysfs directory.
158 158
159 What: /sys/bus/usb/devices/.../<hub_ 159 What: /sys/bus/usb/devices/.../<hub_interface>/port<X>/connect_type
160 Date: January 2013 160 Date: January 2013
161 Contact: Lan Tianyu <tianyu.lan@intel.co 161 Contact: Lan Tianyu <tianyu.lan@intel.com>
162 Description: 162 Description:
163 Some platforms provide usb por 163 Some platforms provide usb port connect types through ACPI.
164 This attribute is to expose th 164 This attribute is to expose these information to user space.
165 The file will read "hotplug", 165 The file will read "hotplug", "hardwired" and "not used" if the
166 information is available, and 166 information is available, and "unknown" otherwise.
167 167
168 What: /sys/bus/usb/devices/.../<hub_ 168 What: /sys/bus/usb/devices/.../<hub_interface>/port<X>/location
169 Date: October 2018 169 Date: October 2018
170 Contact: Bjørn Mork <bjorn@mork.no> 170 Contact: Bjørn Mork <bjorn@mork.no>
171 Description: 171 Description:
172 Some platforms provide usb por 172 Some platforms provide usb port physical location through
173 firmware. This is used by the 173 firmware. This is used by the kernel to pair up logical ports
174 mapping to the same physical c 174 mapping to the same physical connector. The attribute exposes the
175 raw location value as a hex in 175 raw location value as a hex integer.
176 176
177 177
178 What: /sys/bus/usb/devices/.../<hub_ 178 What: /sys/bus/usb/devices/.../<hub_interface>/port<X>/quirks
179 Date: May 2018 179 Date: May 2018
180 Contact: Nicolas Boichat <drinkcat@chrom 180 Contact: Nicolas Boichat <drinkcat@chromium.org>
181 Description: 181 Description:
182 In some cases, we care about t 182 In some cases, we care about time-to-active for devices
183 connected on a specific port ( 183 connected on a specific port (e.g. non-standard USB port like
184 pogo pins), where the device t 184 pogo pins), where the device to be connected is known in
185 advance, and behaves well acco 185 advance, and behaves well according to the specification.
186 This attribute is a bit-field 186 This attribute is a bit-field that controls the behavior of
187 a specific port: 187 a specific port:
188 188
189 - Bit 0 of this field selects 189 - Bit 0 of this field selects the "old" enumeration scheme,
190 as it is considerably faste 190 as it is considerably faster (it only causes one USB reset
191 instead of 2). 191 instead of 2).
192 192
193 The old enumeration scheme 193 The old enumeration scheme can also be selected globally
194 using /sys/module/usbcore/p 194 using /sys/module/usbcore/parameters/old_scheme_first, but
195 it is often not desirable a 195 it is often not desirable as the new scheme was introduced to
196 increase compatibility with 196 increase compatibility with more devices.
197 - Bit 1 reduces TRSTRCY to th 197 - Bit 1 reduces TRSTRCY to the 10 ms that are required by the
198 USB 2.0 specification, inst 198 USB 2.0 specification, instead of the 50 ms that are normally
199 used to help make enumerati 199 used to help make enumeration work better on some high speed
200 devices. 200 devices.
201 201
202 What: /sys/bus/usb/devices/.../<hub_ 202 What: /sys/bus/usb/devices/.../<hub_interface>/port<X>/over_current_count
203 Date: February 2018 203 Date: February 2018
204 Contact: Richard Leitner <richard.leitne 204 Contact: Richard Leitner <richard.leitner@skidata.com>
205 Description: 205 Description:
206 Most hubs are able to detect o 206 Most hubs are able to detect over-current situations on their
207 ports and report them to the k 207 ports and report them to the kernel. This attribute is to expose
208 the number of over-current sit 208 the number of over-current situation occurred on a specific port
209 to user space. This file will 209 to user space. This file will contain an unsigned 32 bit value
210 which wraps to 0 after its max 210 which wraps to 0 after its maximum is reached. This file supports
211 poll() for monitoring changes 211 poll() for monitoring changes to this value in user space.
212 212
213 Any time this value changes th 213 Any time this value changes the corresponding hub device will send a
214 udev event with the following 214 udev event with the following attributes::
215 215
216 OVER_CURRENT_PORT=/sys/bus/u 216 OVER_CURRENT_PORT=/sys/bus/usb/devices/.../<hub_interface>/port<X>
217 OVER_CURRENT_COUNT=[current 217 OVER_CURRENT_COUNT=[current value of this sysfs attribute]
218 218
219 What: /sys/bus/usb/devices/.../<hub_ 219 What: /sys/bus/usb/devices/.../<hub_interface>/port<X>/usb3_lpm_permit
220 Date: November 2015 220 Date: November 2015
221 Contact: Lu Baolu <baolu.lu@linux.intel. 221 Contact: Lu Baolu <baolu.lu@linux.intel.com>
222 Description: 222 Description:
223 Some USB3.0 devices are not fr 223 Some USB3.0 devices are not friendly to USB3 LPM. usb3_lpm_permit
224 attribute allows enabling/disa 224 attribute allows enabling/disabling usb3 lpm of a port. It takes
225 effect both before and after a 225 effect both before and after a usb device is enumerated. Supported
226 values are "0" if both u1 and 226 values are "0" if both u1 and u2 are NOT permitted, "u1" if only u1
227 is permitted, "u2" if only u2 227 is permitted, "u2" if only u2 is permitted, "u1_u2" if both u1 and
228 u2 are permitted. 228 u2 are permitted.
229 229
230 What: /sys/bus/usb/devices/.../<hub_ 230 What: /sys/bus/usb/devices/.../<hub_interface>/port<X>/connector
231 Date: December 2021 231 Date: December 2021
232 Contact: Heikki Krogerus <heikki.krogeru 232 Contact: Heikki Krogerus <heikki.krogerus@linux.intel.com>
233 Description: 233 Description:
234 Link to the USB Type-C connect 234 Link to the USB Type-C connector when available. This link is
235 only created when USB Type-C C 235 only created when USB Type-C Connector Class is enabled, and
236 only if the system firmware is 236 only if the system firmware is capable of describing the
237 connection between a port and 237 connection between a port and its connector.
238 238
239 What: /sys/bus/usb/devices/.../<hub_ 239 What: /sys/bus/usb/devices/.../<hub_interface>/port<X>/disable
240 Date: June 2022 240 Date: June 2022
241 Contact: Michael Grzeschik <m.grzeschik@ 241 Contact: Michael Grzeschik <m.grzeschik@pengutronix.de>
242 Description: 242 Description:
243 This file controls the state o 243 This file controls the state of a USB port, including
244 Vbus power output (but only on 244 Vbus power output (but only on hubs that support
245 power switching -- most hubs d 245 power switching -- most hubs don't support it). If
246 a port is disabled, the port i 246 a port is disabled, the port is unusable: Devices
247 attached to the port will not 247 attached to the port will not be detected, initialized,
248 or enumerated. 248 or enumerated.
249 249
250 What: /sys/bus/usb/devices/.../<hub_ 250 What: /sys/bus/usb/devices/.../<hub_interface>/port<X>/early_stop
251 Date: Sep 2022 251 Date: Sep 2022
252 Contact: Ray Chi <raychi@google.com> 252 Contact: Ray Chi <raychi@google.com>
253 Description: 253 Description:
254 Some USB hosts have some watch 254 Some USB hosts have some watchdog mechanisms so that the device
255 may enter ramdump if it takes 255 may enter ramdump if it takes a long time during port initialization.
256 This attribute allows each por 256 This attribute allows each port just has two attempts so that the
257 port initialization will be fa 257 port initialization will be failed quickly. In addition, if a port
258 which is marked with early_sto 258 which is marked with early_stop has failed to initialize, it will ignore
259 all future connections until t 259 all future connections until this attribute is clear.
260 260
261 What: /sys/bus/usb/devices/.../<hub_ 261 What: /sys/bus/usb/devices/.../<hub_interface>/port<X>/state
262 Date: June 2023 262 Date: June 2023
263 Contact: Roy Luo <royluo@google.com> 263 Contact: Roy Luo <royluo@google.com>
264 Description: 264 Description:
265 Indicates current state of the 265 Indicates current state of the USB device attached to the port.
266 Valid states are: 'not-attache 266 Valid states are: 'not-attached', 'attached', 'powered',
267 'reconnecting', 'unauthenticat 267 'reconnecting', 'unauthenticated', 'default', 'addressed',
268 'configured', and 'suspended'. 268 'configured', and 'suspended'. This file supports poll() to
269 monitor the state change from 269 monitor the state change from user space.
270 270
271 What: /sys/bus/usb/devices/.../power 271 What: /sys/bus/usb/devices/.../power/usb2_lpm_l1_timeout
272 Date: May 2013 272 Date: May 2013
273 Contact: Mathias Nyman <mathias.nyman@li 273 Contact: Mathias Nyman <mathias.nyman@linux.intel.com>
274 Description: 274 Description:
275 USB 2.0 devices may support ha 275 USB 2.0 devices may support hardware link power management (LPM)
276 L1 sleep state. The usb2_lpm_l 276 L1 sleep state. The usb2_lpm_l1_timeout attribute allows
277 tuning the timeout for L1 inac 277 tuning the timeout for L1 inactivity timer (LPM timer), e.g.
278 needed inactivity time before 278 needed inactivity time before host requests the device to go to L1 sleep.
279 Useful for power management tu 279 Useful for power management tuning.
280 Supported values are 0 - 65535 280 Supported values are 0 - 65535 microseconds.
281 281
282 What: /sys/bus/usb/devices/.../power 282 What: /sys/bus/usb/devices/.../power/usb2_lpm_besl
283 Date: May 2013 283 Date: May 2013
284 Contact: Mathias Nyman <mathias.nyman@li 284 Contact: Mathias Nyman <mathias.nyman@linux.intel.com>
285 Description: 285 Description:
286 USB 2.0 devices that support h 286 USB 2.0 devices that support hardware link power management (LPM)
287 L1 sleep state now use a best 287 L1 sleep state now use a best effort service latency value (BESL) to
288 indicate the best effort to re 288 indicate the best effort to resumption of service to the device after the
289 initiation of the resume event 289 initiation of the resume event.
290 If the device does not have a 290 If the device does not have a preferred besl value then the host can select
291 one instead. This usb2_lpm_bes 291 one instead. This usb2_lpm_besl attribute allows to tune the host selected besl
292 value in order to tune power s 292 value in order to tune power saving and service latency.
293 293
294 Supported values are 0 - 15. 294 Supported values are 0 - 15.
295 More information on how besl v 295 More information on how besl values map to microseconds can be found in
296 USB 2.0 ECN Errata for Link Po 296 USB 2.0 ECN Errata for Link Power Management, section 4.10)
297 297
298 What: /sys/bus/usb/devices/.../rx_la 298 What: /sys/bus/usb/devices/.../rx_lanes
299 Date: March 2018 299 Date: March 2018
300 Contact: Mathias Nyman <mathias.nyman@li 300 Contact: Mathias Nyman <mathias.nyman@linux.intel.com>
301 Description: 301 Description:
302 Number of rx lanes the device 302 Number of rx lanes the device is using.
303 USB 3.2 adds Dual-lane support 303 USB 3.2 adds Dual-lane support, 2 rx and 2 tx lanes over Type-C.
304 Inter-Chip SSIC devices suppor 304 Inter-Chip SSIC devices support asymmetric lanes up to 4 lanes per
305 direction. Devices before USB 305 direction. Devices before USB 3.2 are single lane (rx_lanes = 1)
306 306
307 What: /sys/bus/usb/devices/.../tx_la 307 What: /sys/bus/usb/devices/.../tx_lanes
308 Date: March 2018 308 Date: March 2018
309 Contact: Mathias Nyman <mathias.nyman@li 309 Contact: Mathias Nyman <mathias.nyman@linux.intel.com>
310 Description: 310 Description:
311 Number of tx lanes the device 311 Number of tx lanes the device is using.
312 USB 3.2 adds Dual-lane support 312 USB 3.2 adds Dual-lane support, 2 rx and 2 tx -lanes over Type-C.
313 Inter-Chip SSIC devices suppor 313 Inter-Chip SSIC devices support asymmetric lanes up to 4 lanes per
314 direction. Devices before USB 314 direction. Devices before USB 3.2 are single lane (tx_lanes = 1)
315 315
316 What: /sys/bus/usb/devices/.../typec 316 What: /sys/bus/usb/devices/.../typec
317 Date: November 2023 317 Date: November 2023
318 Contact: Heikki Krogerus <heikki.krogeru 318 Contact: Heikki Krogerus <heikki.krogerus@linux.intel.com>
319 Description: 319 Description:
320 Symlink to the USB Type-C part 320 Symlink to the USB Type-C partner device. USB Type-C partner
321 represents the component that 321 represents the component that communicates over the
322 Configuration Channel (CC sign 322 Configuration Channel (CC signal on USB Type-C connectors and
323 cables) with the local port. 323 cables) with the local port.
324 324
325 What: /sys/bus/usb/devices/usbX/bAlt 325 What: /sys/bus/usb/devices/usbX/bAlternateSetting
326 Description: 326 Description:
327 The current interface alternat 327 The current interface alternate setting number, in decimal.
328 328
329 See USB specs for its meaning. 329 See USB specs for its meaning.
330 330
331 What: /sys/bus/usb/devices/usbX/bcdD 331 What: /sys/bus/usb/devices/usbX/bcdDevice
332 Description: 332 Description:
333 The device's release number, i 333 The device's release number, in hexadecimal.
334 334
335 See USB specs for its meaning. 335 See USB specs for its meaning.
336 336
337 What: /sys/bus/usb/devices/usbX/bCon 337 What: /sys/bus/usb/devices/usbX/bConfigurationValue
338 Description: 338 Description:
339 While a USB device typically h 339 While a USB device typically have just one configuration
340 setting, some devices support 340 setting, some devices support multiple configurations.
341 341
342 This value shows the current c 342 This value shows the current configuration, in decimal.
343 343
344 Changing its value will change 344 Changing its value will change the device's configuration
345 to another setting. 345 to another setting.
346 346
347 The number of configurations s 347 The number of configurations supported by a device is at:
348 348
349 /sys/bus/usb/devices/u 349 /sys/bus/usb/devices/usbX/bNumConfigurations
350 350
351 See USB specs for its meaning. 351 See USB specs for its meaning.
352 352
353 What: /sys/bus/usb/devices/usbX/bDev 353 What: /sys/bus/usb/devices/usbX/bDeviceClass
354 Description: 354 Description:
355 Class code of the device, in h 355 Class code of the device, in hexadecimal.
356 356
357 See USB specs for its meaning. 357 See USB specs for its meaning.
358 358
359 What: /sys/bus/usb/devices/usbX/bDev 359 What: /sys/bus/usb/devices/usbX/bDeviceProtocol
360 Description: 360 Description:
361 Protocol code of the device, i 361 Protocol code of the device, in hexadecimal.
362 362
363 See USB specs for its meaning. 363 See USB specs for its meaning.
364 364
365 What: /sys/bus/usb/devices/usbX/bDev 365 What: /sys/bus/usb/devices/usbX/bDeviceSubClass
366 Description: 366 Description:
367 Subclass code of the device, i 367 Subclass code of the device, in hexadecimal.
368 368
369 See USB specs for its meaning. 369 See USB specs for its meaning.
370 370
371 What: /sys/bus/usb/devices/usbX/bInt 371 What: /sys/bus/usb/devices/usbX/bInterfaceClass
372 Description: 372 Description:
373 Class code of the interface, i 373 Class code of the interface, in hexadecimal.
374 374
375 See USB specs for its meaning. 375 See USB specs for its meaning.
376 376
377 What: /sys/bus/usb/devices/usbX/bInt 377 What: /sys/bus/usb/devices/usbX/bInterfaceNumber
378 Description: 378 Description:
379 Interface number, in hexadecim 379 Interface number, in hexadecimal.
380 380
381 See USB specs for its meaning. 381 See USB specs for its meaning.
382 382
383 What: /sys/bus/usb/devices/usbX/bInt 383 What: /sys/bus/usb/devices/usbX/bInterfaceProtocol
384 Description: 384 Description:
385 Protocol code of the interface 385 Protocol code of the interface, in hexadecimal.
386 386
387 See USB specs for its meaning. 387 See USB specs for its meaning.
388 388
389 What: /sys/bus/usb/devices/usbX/bInt 389 What: /sys/bus/usb/devices/usbX/bInterfaceSubClass
390 Description: 390 Description:
391 Subclass code of the interface 391 Subclass code of the interface, in hexadecimal.
392 392
393 See USB specs for its meaning. 393 See USB specs for its meaning.
394 394
395 What: /sys/bus/usb/devices/usbX/bmAt 395 What: /sys/bus/usb/devices/usbX/bmAttributes
396 Description: 396 Description:
397 Attributes of the current conf 397 Attributes of the current configuration, in hexadecimal.
398 398
399 See USB specs for its meaning. 399 See USB specs for its meaning.
400 400
401 What: /sys/bus/usb/devices/usbX/bMax 401 What: /sys/bus/usb/devices/usbX/bMaxPacketSize0
402 Description: 402 Description:
403 Maximum endpoint 0 packet size 403 Maximum endpoint 0 packet size, in decimal.
404 404
405 See USB specs for its meaning. 405 See USB specs for its meaning.
406 406
407 What: /sys/bus/usb/devices/usbX/bMax 407 What: /sys/bus/usb/devices/usbX/bMaxPower
408 Description: 408 Description:
409 Maximum power consumption of t 409 Maximum power consumption of the active configuration of
410 the device, in miliamperes. 410 the device, in miliamperes.
411 411
412 What: /sys/bus/usb/devices/usbX/bNum 412 What: /sys/bus/usb/devices/usbX/bNumConfigurations
413 Description: 413 Description:
414 Number of the possible configu 414 Number of the possible configurations of the device, in
415 decimal. The current configura 415 decimal. The current configuration is controlled via:
416 416
417 /sys/bus/usb/devices/u 417 /sys/bus/usb/devices/usbX/bConfigurationValue
418 418
419 See USB specs for its meaning. 419 See USB specs for its meaning.
420 420
421 What: /sys/bus/usb/devices/usbX/bNum 421 What: /sys/bus/usb/devices/usbX/bNumEndpoints
422 Description: 422 Description:
423 Number of endpoints used on th 423 Number of endpoints used on this interface, in hexadecimal.
424 424
425 See USB specs for its meaning. 425 See USB specs for its meaning.
426 426
427 What: /sys/bus/usb/devices/usbX/bNum 427 What: /sys/bus/usb/devices/usbX/bNumInterfaces
428 Description: 428 Description:
429 Number of interfaces on this d 429 Number of interfaces on this device, in decimal.
430 430
431 What: /sys/bus/usb/devices/usbX/busn 431 What: /sys/bus/usb/devices/usbX/busnum
432 Description: 432 Description:
433 Number of the bus. 433 Number of the bus.
434 434
435 What: /sys/bus/usb/devices/usbX/conf 435 What: /sys/bus/usb/devices/usbX/configuration
436 Description: 436 Description:
437 Contents of the string descrip 437 Contents of the string descriptor associated with the
438 current configuration. It may 438 current configuration. It may include the firmware version
439 of a device and/or its serial 439 of a device and/or its serial number.
440 440
441 What: /sys/bus/usb/devices/usbX/desc 441 What: /sys/bus/usb/devices/usbX/descriptors
442 Description: 442 Description:
443 Contains the interface descrip 443 Contains the interface descriptors, in binary.
444 444
445 What: /sys/bus/usb/devices/usbX/bos_ 445 What: /sys/bus/usb/devices/usbX/bos_descriptors
446 Date: March 2024 446 Date: March 2024
447 Contact: Elbert Mai <code@elbertmai.com> 447 Contact: Elbert Mai <code@elbertmai.com>
448 Description: 448 Description:
449 Binary file containing the cac 449 Binary file containing the cached binary device object store (BOS)
450 of the device. This consists o 450 of the device. This consists of the BOS descriptor followed by the
451 set of device capability descr 451 set of device capability descriptors. All descriptors read from
452 this file are in bus-endian fo 452 this file are in bus-endian format. Note that the kernel will not
453 request the BOS from a device 453 request the BOS from a device if its bcdUSB is less than 0x0201.
454 454
455 What: /sys/bus/usb/devices/usbX/idPr 455 What: /sys/bus/usb/devices/usbX/idProduct
456 Description: 456 Description:
457 Product ID, in hexadecimal. 457 Product ID, in hexadecimal.
458 458
459 What: /sys/bus/usb/devices/usbX/idVe 459 What: /sys/bus/usb/devices/usbX/idVendor
460 Description: 460 Description:
461 Vendor ID, in hexadecimal. 461 Vendor ID, in hexadecimal.
462 462
463 What: /sys/bus/usb/devices/usbX/devs 463 What: /sys/bus/usb/devices/usbX/devspec
464 Description: 464 Description:
465 Displays the Device Tree Open 465 Displays the Device Tree Open Firmware node of the interface.
466 466
467 What: /sys/bus/usb/devices/usbX/avoi 467 What: /sys/bus/usb/devices/usbX/avoid_reset_quirk
468 Description: 468 Description:
469 Most devices have this set to 469 Most devices have this set to zero.
470 470
471 If the value is 1, enable a US 471 If the value is 1, enable a USB quirk that prevents this
472 device to use reset. 472 device to use reset.
473 473
474 (read/write) 474 (read/write)
475 475
476 What: /sys/bus/usb/devices/usbX/devn 476 What: /sys/bus/usb/devices/usbX/devnum
477 Description: 477 Description:
478 USB interface device number, i 478 USB interface device number, in decimal.
479 479
480 What: /sys/bus/usb/devices/usbX/devp 480 What: /sys/bus/usb/devices/usbX/devpath
481 Description: 481 Description:
482 String containing the USB inte 482 String containing the USB interface device path.
483 483
484 What: /sys/bus/usb/devices/usbX/manu 484 What: /sys/bus/usb/devices/usbX/manufacturer
485 Description: 485 Description:
486 Vendor specific string contain 486 Vendor specific string containing the name of the
487 manufacturer of the device. 487 manufacturer of the device.
488 488
489 What: /sys/bus/usb/devices/usbX/maxc 489 What: /sys/bus/usb/devices/usbX/maxchild
490 Description: 490 Description:
491 Number of ports of an USB hub 491 Number of ports of an USB hub
492 492
493 What: /sys/bus/usb/devices/usbX/pers 493 What: /sys/bus/usb/devices/usbX/persist
494 Description: 494 Description:
495 Keeps the device even if it ge 495 Keeps the device even if it gets disconnected.
496 496
497 What: /sys/bus/usb/devices/usbX/prod 497 What: /sys/bus/usb/devices/usbX/product
498 Description: 498 Description:
499 Vendor specific string contain 499 Vendor specific string containing the name of the
500 device's product. 500 device's product.
501 501
502 What: /sys/bus/usb/devices/usbX/spee 502 What: /sys/bus/usb/devices/usbX/speed
503 Description: 503 Description:
504 Shows the device's max speed, 504 Shows the device's max speed, according to the USB version,
505 in Mbps. 505 in Mbps.
506 Can be: 506 Can be:
507 507
508 ======= ====== 508 ======= ====================
509 Unknown speed 509 Unknown speed unknown
510 1.5 Low sp 510 1.5 Low speed
511 15 Full s 511 15 Full speed
512 480 High S 512 480 High Speed
513 5000 Super 513 5000 Super Speed
514 10000 Super 514 10000 Super Speed+
515 20000 Super 515 20000 Super Speed+ Gen 2x2
516 ======= ====== 516 ======= ====================
517 517
518 What: /sys/bus/usb/devices/usbX/supp 518 What: /sys/bus/usb/devices/usbX/supports_autosuspend
519 Description: 519 Description:
520 Returns 1 if the device doesn' 520 Returns 1 if the device doesn't support autosuspend.
521 Otherwise, returns 0. 521 Otherwise, returns 0.
522 522
523 What: /sys/bus/usb/devices/usbX/urbn 523 What: /sys/bus/usb/devices/usbX/urbnum
524 Description: 524 Description:
525 Number of URBs submitted for t 525 Number of URBs submitted for the whole device.
526 526
527 What: /sys/bus/usb/devices/usbX/vers 527 What: /sys/bus/usb/devices/usbX/version
528 Description: 528 Description:
529 String containing the USB devi 529 String containing the USB device version, as encoded
530 at the BCD descriptor. 530 at the BCD descriptor.
531 531
532 What: /sys/bus/usb/devices/usbX/powe 532 What: /sys/bus/usb/devices/usbX/power/autosuspend
533 Description: 533 Description:
534 Time in milliseconds for the d 534 Time in milliseconds for the device to autosuspend. If the
535 value is negative, then autosu 535 value is negative, then autosuspend is prevented.
536 536
537 (read/write) 537 (read/write)
538 538
539 What: /sys/bus/usb/devices/usbX/powe 539 What: /sys/bus/usb/devices/usbX/power/active_duration
540 Description: 540 Description:
541 The total time the device has 541 The total time the device has not been suspended.
542 542
543 What: /sys/bus/usb/devices/usbX/powe 543 What: /sys/bus/usb/devices/usbX/power/connected_duration
544 Description: 544 Description:
545 The total time (in msec) that 545 The total time (in msec) that the device has been connected.
546 546
547 What: /sys/bus/usb/devices/usbX/powe 547 What: /sys/bus/usb/devices/usbX/power/level
548 Description: 548 Description:
549 549
550 What: /sys/bus/usb/devices/usbX/ep_< 550 What: /sys/bus/usb/devices/usbX/ep_<N>/bEndpointAddress
551 Description: 551 Description:
552 The address of the endpoint de 552 The address of the endpoint described by this descriptor,
553 in hexadecimal. The endpoint d 553 in hexadecimal. The endpoint direction on this bitmapped field
554 is also shown at: 554 is also shown at:
555 555
556 /sys/bus/usb/devices/u 556 /sys/bus/usb/devices/usbX/ep_<N>/direction
557 557
558 See USB specs for its meaning. 558 See USB specs for its meaning.
559 559
560 What: /sys/bus/usb/devices/usbX/ep_< 560 What: /sys/bus/usb/devices/usbX/ep_<N>/bInterval
561 Description: 561 Description:
562 The interval of the endpoint a 562 The interval of the endpoint as described on its descriptor,
563 in hexadecimal. The actual int 563 in hexadecimal. The actual interval depends on the version
564 of the USB. Also shown in time 564 of the USB. Also shown in time units at
565 /sys/bus/usb/devices/usbX/ep_< 565 /sys/bus/usb/devices/usbX/ep_<N>/interval.
566 566
567 What: /sys/bus/usb/devices/usbX/ep_< 567 What: /sys/bus/usb/devices/usbX/ep_<N>/bLength
568 Description: 568 Description:
569 Number of bytes of the endpoin 569 Number of bytes of the endpoint descriptor, in hexadecimal.
570 570
571 What: /sys/bus/usb/devices/usbX/ep_< 571 What: /sys/bus/usb/devices/usbX/ep_<N>/bmAttributes
572 Description: 572 Description:
573 Attributes which apply to the 573 Attributes which apply to the endpoint as described on its
574 descriptor, in hexadecimal. Th 574 descriptor, in hexadecimal. The endpoint type on this
575 bitmapped field is also shown 575 bitmapped field is also shown at:
576 576
577 /sys/bus/usb/devices/u 577 /sys/bus/usb/devices/usbX/ep_<N>/type
578 578
579 See USB specs for its meaning. 579 See USB specs for its meaning.
580 580
581 What: /sys/bus/usb/devices/usbX/ep_< 581 What: /sys/bus/usb/devices/usbX/ep_<N>/direction
582 Description: 582 Description:
583 Direction of the endpoint. Can 583 Direction of the endpoint. Can be:
584 584
585 - both (on control endpoin 585 - both (on control endpoints)
586 - in 586 - in
587 - out 587 - out
588 588
589 What: /sys/bus/usb/devices/usbX/ep_< 589 What: /sys/bus/usb/devices/usbX/ep_<N>/interval
590 Description: 590 Description:
591 Interval for polling endpoint 591 Interval for polling endpoint for data transfers, in
592 milisseconds or microseconds. 592 milisseconds or microseconds.
593 593
594 What: /sys/bus/usb/devices/usbX/ep_< 594 What: /sys/bus/usb/devices/usbX/ep_<N>/type
595 Description: 595 Description:
596 Descriptor type. Can be: 596 Descriptor type. Can be:
597 597
598 - Control 598 - Control
599 - Isoc 599 - Isoc
600 - Bulk 600 - Bulk
601 - Interrupt 601 - Interrupt
602 - unknown 602 - unknown
603 603
604 What: /sys/bus/usb/devices/usbX/ep_< 604 What: /sys/bus/usb/devices/usbX/ep_<N>/wMaxPacketSize
605 Description: 605 Description:
606 Maximum packet size this endpo 606 Maximum packet size this endpoint is capable of
607 sending or receiving, in hexad 607 sending or receiving, in hexadecimal.
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