What:		/sys/bus/usb/devices/.../power/autosuspendDate:		March 2007KernelVersion:	2.6.21Contact:	Alan Stern <stern@rowland.harvard.edu>Description:		Each USB device directory will contain a file named		power/autosuspend.  This file holds the time (in seconds)		the device must be idle before it will be autosuspended.		0 means the device will be autosuspended as soon as		possible.  Negative values will prevent the device from		being autosuspended at all, and writing a negative value		will resume the device if it is already suspended.		The autosuspend delay for newly-created devices is set to		the value of the usbcore.autosuspend module parameter.What:		/sys/bus/usb/devices/.../power/levelDate:		March 2007KernelVersion:	2.6.21Contact:	Alan Stern <stern@rowland.harvard.edu>Description:		Each USB device directory will contain a file named		power/level.  This file holds a power-level setting for		the device, one of "on", "auto", or "suspend".		"on" means that the device is not allowed to autosuspend,		although normal suspends for system sleep will still		be honored.  "auto" means the device will autosuspend		and autoresume in the usual manner, according to the		capabilities of its driver.  "suspend" means the device		is forced into a suspended state and it will not autoresume		in response to I/O requests.  However remote-wakeup requests		from the device may still be enabled (the remote-wakeup		setting is controlled separately by the power/wakeup		attribute).		During normal use, devices should be left in the "auto"		level.  The other levels are meant for administrative uses.		If you want to suspend a device immediately but leave it		free to wake up in response to I/O requests, you should		write "0" to power/autosuspend.What:		/sys/bus/usb/devices/.../power/persistDate:		May 2007KernelVersion:	2.6.23Contact:	Alan Stern <stern@rowland.harvard.edu>Description:		If CONFIG_USB_PERSIST is set, then each USB device directory		will contain a file named power/persist.  The file holds a		boolean value (0 or 1) indicating whether or not the		"USB-Persist" facility is enabled for the device.  Since the		facility is inherently dangerous, it is disabled by default		for all devices except hubs.  For more information, see		Documentation/usb/persist.txt.What:		/sys/bus/usb/device/.../power/connected_durationDate:		January 2008KernelVersion:	2.6.25Contact:	Sarah Sharp <sarah.a.sharp@intel.com>Description:		If CONFIG_PM and CONFIG_USB_SUSPEND are enabled, then this file		is present.  When read, it returns the total time (in msec)		that the USB device has been connected to the machine.  This		file is read-only.Users:		PowerTOP <power@bughost.org>		http://www.lesswatts.org/projects/powertop/What:		/sys/bus/usb/device/.../power/active_durationDate:		January 2008KernelVersion:	2.6.25Contact:	Sarah Sharp <sarah.a.sharp@intel.com>Description:		If CONFIG_PM and CONFIG_USB_SUSPEND are enabled, then this file		is present.  When read, it returns the total time (in msec)		that the USB device has been active, i.e. not in a suspended		state.  This file is read-only.		Tools can use this file and the connected_duration file to		compute the percentage of time that a device has been active.		For example,		echo $((100 * `cat active_duration` / `cat connected_duration`))		will give an integer percentage.  Note that this does not		account for counter wrap.Users:		PowerTOP <power@bughost.org>		http://www.lesswatts.org/projects/powertop/What:		/sys/bus/usb/device/<busnum>-<devnum>...:<config num>-<interface num>/supports_autosuspendDate:		January 2008KernelVersion:	2.6.27Contact:	Sarah Sharp <sarah.a.sharp@intel.com>Description:		When read, this file returns 1 if the interface driver		for this interface supports autosuspend.  It also		returns 1 if no driver has claimed this interface, as an		unclaimed interface will not stop the device from being		autosuspended if all other interface drivers are idle.		The file returns 0 if autosuspend support has not been		added to the driver.Users:		USB PM tool		git://git.moblin.org/users/sarah/usb-pm-tool/What:		/sys/bus/usb/device/.../authorizedDate:		July 2008KernelVersion:	2.6.26Contact:	David Vrabel <david.vrabel@csr.com>Description:		Authorized devices are available for use by device		drivers, non-authorized one are not.  By default, wired		USB devices are authorized.		Certified Wireless USB devices are not authorized		initially and should be (by writing 1) after the		device has been authenticated.What:		/sys/bus/usb/device/.../wusb_cdidDate:		July 2008KernelVersion:	2.6.27Contact:	David Vrabel <david.vrabel@csr.com>Description:		For Certified Wireless USB devices only.		A devices's CDID, as 16 space-separated hex octets.What:		/sys/bus/usb/device/.../wusb_ckDate:		July 2008KernelVersion:	2.6.27Contact:	David Vrabel <david.vrabel@csr.com>Description:		For Certified Wireless USB devices only.		Write the device's connection key (CK) to start the		authentication of the device.  The CK is 16		space-separated hex octets.What:		/sys/bus/usb/device/.../wusb_disconnectDate:		July 2008KernelVersion:	2.6.27Contact:	David Vrabel <david.vrabel@csr.com>Description:		For Certified Wireless USB devices only.		Write a 1 to force the device to disconnect		(equivalent to unplugging a wired USB device).