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Based on kernel version 4.2. Page generated on 2015-09-09 12:07 EST.

1	What:		/sys/bus/usb/device/.../authorized
2	Date:		July 2008
3	KernelVersion:	2.6.26
4	Contact:	David Vrabel <david.vrabel@csr.com>
5	Description:
6			Authorized devices are available for use by device
7			drivers, non-authorized one are not.  By default, wired
8			USB devices are authorized.
10			Certified Wireless USB devices are not authorized
11			initially and should be (by writing 1) after the
12			device has been authenticated.
14	What:		/sys/bus/usb/device/.../wusb_cdid
15	Date:		July 2008
16	KernelVersion:	2.6.27
17	Contact:	David Vrabel <david.vrabel@csr.com>
18	Description:
19			For Certified Wireless USB devices only.
21			A devices's CDID, as 16 space-separated hex octets.
23	What:		/sys/bus/usb/device/.../wusb_ck
24	Date:		July 2008
25	KernelVersion:	2.6.27
26	Contact:	David Vrabel <david.vrabel@csr.com>
27	Description:
28			For Certified Wireless USB devices only.
30			Write the device's connection key (CK) to start the
31			authentication of the device.  The CK is 16
32			space-separated hex octets.
34	What:		/sys/bus/usb/device/.../wusb_disconnect
35	Date:		July 2008
36	KernelVersion:	2.6.27
37	Contact:	David Vrabel <david.vrabel@csr.com>
38	Description:
39			For Certified Wireless USB devices only.
41			Write a 1 to force the device to disconnect
42			(equivalent to unplugging a wired USB device).
44	What:		/sys/bus/usb/drivers/.../new_id
45	Date:		October 2011
46	Contact:	linux-usb@vger.kernel.org
47	Description:
48			Writing a device ID to this file will attempt to
49			dynamically add a new device ID to a USB device driver.
50			This may allow the driver to support more hardware than
51			was included in the driver's static device ID support
52			table at compile time. The format for the device ID is:
53			idVendor idProduct bInterfaceClass RefIdVendor RefIdProduct
54			The vendor ID and device ID fields are required, the
55			rest is optional. The Ref* tuple can be used to tell the
56			driver to use the same driver_data for the new device as
57			it is used for the reference device.
58			Upon successfully adding an ID, the driver will probe
59			for the device and attempt to bind to it.  For example:
60			# echo "8086 10f5" > /sys/bus/usb/drivers/foo/new_id
62			Here add a new device (0458:7045) using driver_data from
63			an already supported device (0458:704c):
64			# echo "0458 7045 0 0458 704c" > /sys/bus/usb/drivers/foo/new_id
66			Reading from this file will list all dynamically added
67			device IDs in the same format, with one entry per
68			line. For example:
69			# cat /sys/bus/usb/drivers/foo/new_id
70			8086 10f5
71			dead beef 06
72			f00d cafe
74			The list will be truncated at PAGE_SIZE bytes due to
75			sysfs restrictions.
77	What:		/sys/bus/usb-serial/drivers/.../new_id
78	Date:		October 2011
79	Contact:	linux-usb@vger.kernel.org
80	Description:
81			For serial USB drivers, this attribute appears under the
82			extra bus folder "usb-serial" in sysfs; apart from that
83			difference, all descriptions from the entry
84			"/sys/bus/usb/drivers/.../new_id" apply.
86	What:		/sys/bus/usb/drivers/.../remove_id
87	Date:		November 2009
88	Contact:	CHENG Renquan <rqcheng@smu.edu.sg>
89	Description:
90			Writing a device ID to this file will remove an ID
91			that was dynamically added via the new_id sysfs entry.
92			The format for the device ID is:
93			idVendor idProduct.	After successfully
94			removing an ID, the driver will no longer support the
95			device.  This is useful to ensure auto probing won't
96			match the driver to the device.  For example:
97			# echo "046d c315" > /sys/bus/usb/drivers/foo/remove_id
99			Reading from this file will list the dynamically added
100			device IDs, exactly like reading from the entry
101			"/sys/bus/usb/drivers/.../new_id"
103	What:		/sys/bus/usb/devices/.../power/usb2_hardware_lpm
104	Date:		September 2011
105	Contact:	Andiry Xu <andiry.xu@amd.com>
106	Description:
107			If CONFIG_PM is set and a USB 2.0 lpm-capable device is plugged
108			in to a xHCI host which support link PM, it will perform a LPM
109			test; if the test is passed and host supports USB2 hardware LPM
110			(xHCI 1.0 feature), USB2 hardware LPM will be enabled for the
111			device and the USB device directory will contain a file named
112			power/usb2_hardware_lpm.  The file holds a string value (enable
113			or disable) indicating whether or not USB2 hardware LPM is
114			enabled for the device. Developer can write y/Y/1 or n/N/0 to
115			the file to enable/disable the feature.
117	What:		/sys/bus/usb/devices/.../removable
118	Date:		February 2012
119	Contact:	Matthew Garrett <mjg@redhat.com>
120	Description:
121			Some information about whether a given USB device is
122			physically fixed to the platform can be inferred from a
123			combination of hub descriptor bits and platform-specific data
124			such as ACPI. This file will read either "removable" or
125			"fixed" if the information is available, and "unknown"
126			otherwise.
128	What:		/sys/bus/usb/devices/.../ltm_capable
129	Date:		July 2012
130	Contact:	Sarah Sharp <sarah.a.sharp@linux.intel.com>
131	Description:
132			USB 3.0 devices may optionally support Latency Tolerance
133			Messaging (LTM).  They indicate their support by setting a bit
134			in the bmAttributes field of their SuperSpeed BOS descriptors.
135			If that bit is set for the device, ltm_capable will read "yes".
136			If the device doesn't support LTM, the file will read "no".
137			The file will be present for all speeds of USB devices, and will
138			always read "no" for USB 1.1 and USB 2.0 devices.
140	What:		/sys/bus/usb/devices/.../(hub interface)/portX
141	Date:		August 2012
142	Contact:	Lan Tianyu <tianyu.lan@intel.com>
143	Description:
144			The /sys/bus/usb/devices/.../(hub interface)/portX
145			is usb port device's sysfs directory.
147	What:		/sys/bus/usb/devices/.../(hub interface)/portX/connect_type
148	Date:		January 2013
149	Contact:	Lan Tianyu <tianyu.lan@intel.com>
150	Description:
151			Some platforms provide usb port connect types through ACPI.
152			This attribute is to expose these information to user space.
153			The file will read "hotplug", "wired" and "not used" if the
154			information is available, and "unknown" otherwise.
156	What:		/sys/bus/usb/devices/.../power/usb2_lpm_l1_timeout
157	Date:		May 2013
158	Contact:	Mathias Nyman <mathias.nyman@linux.intel.com>
159	Description:
160			USB 2.0 devices may support hardware link power management (LPM)
161			L1 sleep state. The usb2_lpm_l1_timeout attribute allows
162			tuning the timeout for L1 inactivity timer (LPM timer), e.g.
163			needed inactivity time before host requests the device to go to L1 sleep.
164			Useful for power management tuning.
165			Supported values are 0 - 65535 microseconds.
167	What:		/sys/bus/usb/devices/.../power/usb2_lpm_besl
168	Date:		May 2013
169	Contact:	Mathias Nyman <mathias.nyman@linux.intel.com>
170	Description:
171			USB 2.0 devices that support hardware link power management (LPM)
172			L1 sleep state now use a best effort service latency value (BESL) to
173			indicate the best effort to resumption of service to the device after the
174			initiation of the resume event.
175			If the device does not have a preferred besl value then the host can select
176			one instead. This usb2_lpm_besl attribute allows to tune the host selected besl
177			value in order to tune power saving and service latency.
179			Supported values are 0 - 15.
180			More information on how besl values map to microseconds can be found in
181			USB 2.0 ECN Errata for Link Power Management, section 4.10)
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