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Based on kernel version 3.13. Page generated on 2014-01-20 21:59 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.
54			The vendor ID and device ID fields are required, the
55			interface class is optional.
56			Upon successfully adding an ID, the driver will probe
57			for the device and attempt to bind to it.  For example:
58			# echo "8086 10f5" > /sys/bus/usb/drivers/foo/new_id
60			Reading from this file will list all dynamically added
61			device IDs in the same format, with one entry per
62			line. For example:
63			# cat /sys/bus/usb/drivers/foo/new_id
64			8086 10f5
65			dead beef 06
66			f00d cafe
68			The list will be truncated at PAGE_SIZE bytes due to
69			sysfs restrictions.
71	What:		/sys/bus/usb-serial/drivers/.../new_id
72	Date:		October 2011
73	Contact:	linux-usb@vger.kernel.org
74	Description:
75			For serial USB drivers, this attribute appears under the
76			extra bus folder "usb-serial" in sysfs; apart from that
77			difference, all descriptions from the entry
78			"/sys/bus/usb/drivers/.../new_id" apply.
80	What:		/sys/bus/usb/drivers/.../remove_id
81	Date:		November 2009
82	Contact:	CHENG Renquan <rqcheng@smu.edu.sg>
83	Description:
84			Writing a device ID to this file will remove an ID
85			that was dynamically added via the new_id sysfs entry.
86			The format for the device ID is:
87			idVendor idProduct.	After successfully
88			removing an ID, the driver will no longer support the
89			device.  This is useful to ensure auto probing won't
90			match the driver to the device.  For example:
91			# echo "046d c315" > /sys/bus/usb/drivers/foo/remove_id
93			Reading from this file will list the dynamically added
94			device IDs, exactly like reading from the entry
95			"/sys/bus/usb/drivers/.../new_id"
97	What:		/sys/bus/usb/devices/.../power/usb2_hardware_lpm
98	Date:		September 2011
99	Contact:	Andiry Xu <andiry.xu@amd.com>
100	Description:
101			If CONFIG_PM_RUNTIME is set and a USB 2.0 lpm-capable device
102			is plugged in to a xHCI host which support link PM, it will
103			perform a LPM test; if the test is passed and host supports
104			USB2 hardware LPM (xHCI 1.0 feature), USB2 hardware LPM will
105			be enabled for the device and the USB device directory will
106			contain a file named power/usb2_hardware_lpm.  The file holds
107			a string value (enable or disable) indicating whether or not
108			USB2 hardware LPM is enabled for the device. Developer can
109			write y/Y/1 or n/N/0 to the file to enable/disable the
110			feature.
112	What:		/sys/bus/usb/devices/.../removable
113	Date:		February 2012
114	Contact:	Matthew Garrett <mjg@redhat.com>
115	Description:
116			Some information about whether a given USB device is
117			physically fixed to the platform can be inferred from a
118			combination of hub descriptor bits and platform-specific data
119			such as ACPI. This file will read either "removable" or
120			"fixed" if the information is available, and "unknown"
121			otherwise.
123	What:		/sys/bus/usb/devices/.../ltm_capable
124	Date:		July 2012
125	Contact:	Sarah Sharp <sarah.a.sharp@linux.intel.com>
126	Description:
127			USB 3.0 devices may optionally support Latency Tolerance
128			Messaging (LTM).  They indicate their support by setting a bit
129			in the bmAttributes field of their SuperSpeed BOS descriptors.
130			If that bit is set for the device, ltm_capable will read "yes".
131			If the device doesn't support LTM, the file will read "no".
132			The file will be present for all speeds of USB devices, and will
133			always read "no" for USB 1.1 and USB 2.0 devices.
135	What:		/sys/bus/usb/devices/.../(hub interface)/portX
136	Date:		August 2012
137	Contact:	Lan Tianyu <tianyu.lan@intel.com>
138	Description:
139			The /sys/bus/usb/devices/.../(hub interface)/portX
140			is usb port device's sysfs directory.
142	What:		/sys/bus/usb/devices/.../(hub interface)/portX/connect_type
143	Date:		January 2013
144	Contact:	Lan Tianyu <tianyu.lan@intel.com>
145	Description:
146			Some platforms provide usb port connect types through ACPI.
147			This attribute is to expose these information to user space.
148			The file will read "hotplug", "wired" and "not used" if the
149			information is available, and "unknown" otherwise.
151	What:		/sys/bus/usb/devices/.../power/usb2_lpm_l1_timeout
152	Date:		May 2013
153	Contact:	Mathias Nyman <mathias.nyman@linux.intel.com>
154	Description:
155			USB 2.0 devices may support hardware link power management (LPM)
156			L1 sleep state. The usb2_lpm_l1_timeout attribute allows
157			tuning the timeout for L1 inactivity timer (LPM timer), e.g.
158			needed inactivity time before host requests the device to go to L1 sleep.
159			Useful for power management tuning.
160			Supported values are 0 - 65535 microseconds.
162	What:		/sys/bus/usb/devices/.../power/usb2_lpm_besl
163	Date:		May 2013
164	Contact:	Mathias Nyman <mathias.nyman@linux.intel.com>
165	Description:
166			USB 2.0 devices that support hardware link power management (LPM)
167			L1 sleep state now use a best effort service latency value (BESL) to
168			indicate the best effort to resumption of service to the device after the
169			initiation of the resume event.
170			If the device does not have a preferred besl value then the host can select
171			one instead. This usb2_lpm_besl attribute allows to tune the host selected besl
172			value in order to tune power saving and service latency.
174			Supported values are 0 - 15.
175			More information on how besl values map to microseconds can be found in
176			USB 2.0 ECN Errata for Link Power Management, section 4.10)
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