What:		/config/usb-gadget
Date:		Jun 2013
KernelVersion:	3.11
Description:
		This group contains sub-groups corresponding to created
		USB gadgets.

What:		/config/usb-gadget/gadget
Date:		Jun 2013
KernelVersion:	3.11
Description:

		The attributes of a gadget:

		UDC		- bind a gadget to UDC/unbind a gadget;
				write UDC's name found in /sys/class/udc/*
				to bind a gadget, empty string "" to unbind.

		bDeviceClass	- USB device class code
		bDeviceSubClass	- USB device subclass code
		bDeviceProtocol	- USB device protocol code
		bMaxPacketSize0	- maximum endpoint 0 packet size
		bcdDevice	- bcd device release number
		bcdUSB		- bcd USB specification version number
		idProduct	- product ID
		idVendor	- vendor ID

What:		/config/usb-gadget/gadget/configs
Date:		Jun 2013
KernelVersion:	3.11
Description:
		This group contains a USB gadget's configurations

What:		/config/usb-gadget/gadget/configs/config
Date:		Jun 2013
KernelVersion:	3.11
Description:
		The attributes of a configuration:

		bmAttributes	- configuration characteristics
		MaxPower	- maximum power consumption from the bus

What:		/config/usb-gadget/gadget/configs/config/strings
Date:		Jun 2013
KernelVersion:	3.11
Description:
		This group contains subdirectories for language-specific
		strings for this configuration.

What:		/config/usb-gadget/gadget/configs/config/strings/language
Date:		Jun 2013
KernelVersion:	3.11
Description:
		The attributes:

		configuration	- configuration description


What:		/config/usb-gadget/gadget/functions
Date:		Jun 2013
KernelVersion:	3.11
Description:
		This group contains functions available to this USB gadget.

What:		/config/usb-gadget/gadget/functions/<func>.<inst>/interface.<n>
Date:		May 2014
KernelVersion:	3.16
Description:
		This group contains "Feature Descriptors" specific for one
		gadget's USB interface or one interface group described
		by an IAD.

		The attributes:

		compatible_id		- 8-byte string for "Compatible ID"
		sub_compatible_id	- 8-byte string for "Sub Compatible ID"

What:		/config/usb-gadget/gadget/functions/<func>.<inst>/interface.<n>/<property>
Date:		May 2014
KernelVersion:	3.16
Description:
		This group contains "Extended Property Descriptors" specific for one
		gadget's USB interface or one interface group described
		by an IAD.

		The attributes:

		type		- value 1..7 for interpreting the data
				1: unicode string
				2: unicode string with environment variable
				3: binary
				4: little-endian 32-bit
				5: big-endian 32-bit
				6: unicode string with a symbolic link
				7: multiple unicode strings
		data		- blob of data to be interpreted depending on
				type

What:		/config/usb-gadget/gadget/strings
Date:		Jun 2013
KernelVersion:	3.11
Description:
		This group contains subdirectories for language-specific
		strings for this gadget.

What:		/config/usb-gadget/gadget/strings/language
Date:		Jun 2013
KernelVersion:	3.11
Description:
		The attributes:

		serialnumber	- gadget's serial number (string)
		product		- gadget's product description
		manufacturer	- gadget's manufacturer description

What:		/config/usb-gadget/gadget/os_desc
Date:		May 2014
KernelVersion:	3.16
Description:
		This group contains "OS String" extension handling attributes.

		use		- flag turning "OS Desctiptors" support on/off
		b_vendor_code	- one-byte value used for custom per-device and
				per-interface requests
		qw_sign		- an identifier to be reported as "OS String"
				proper
