Provided by:
linux-doc-2.6.15_2.6.15-23.39_all 
NAME
struct usb_gadget - represents a usb slave device
SYNOPSIS
struct usb_gadget {
const struct usb_gadget_ops * ops;
struct usb_ep * ep0;
struct list_head ep_list;
enum usb_device_speed speed;
unsigned is_dualspeed:1;
unsigned is_otg:1;
unsigned is_a_peripheral:1;
unsigned b_hnp_enable:1;
unsigned a_hnp_support:1;
unsigned a_alt_hnp_support:1;
const char * name;
struct device dev;
};
MEMBERS
ops Function pointers used to access hardware-specific operations.
ep0 Endpoint zero, used when reading or writing responses to driver
setup requests
ep_list
List of other endpoints supported by the device.
speed Speed of current connection to USB host.
is_dualspeed
True if the controller supports both high and full speed
operation. If it does, the gadget driver must also support both.
is_otg True if the USB device port uses a Mini-AB jack, so that the
gadget driver must provide a USB OTG descriptor.
is_a_peripheral
False unless is_otg, the ‘‘A’’ end of a USB cable is in the
Mini-AB jack, and HNP has been used to switch roles so that the
‘‘A’’ device currently acts as A-Peripheral, not A-Host.
b_hnp_enable
OTG device feature flag, indicating that the A-Host enabled HNP
support.
a_hnp_support
OTG device feature flag, indicating that the A-Host supports HNP
at this port.
a_alt_hnp_support
OTG device feature flag, indicating that the A-Host only
supports HNP on a different root port.
name Identifies the controller hardware type. Used in diagnostics and
sometimes configuration.
dev Driver model state for this abstract device.
DESCRIPTION
Gadgets have a mostly-portable ‘‘gadget driver’’ implementing device
functions, handling all usb configurations and interfaces. Gadget
drivers talk to hardware-specific code indirectly, through ops vectors.
That insulates the gadget driver from hardware details, and packages
the hardware endpoints through generic i/o queues. The ‘‘usb_gadget’’
and ‘‘usb_ep’’ interfaces provide that insulation from the hardware.
Except for the driver data, all fields in this structure are read-only
to the gadget driver. That driver data is part of the ‘‘driver model’’
infrastructure in 2.6 (and later) kernels, and for earlier systems is
grouped in a similar structure that’s not known to the rest of the
kernel.
Values of the three OTG device feature flags are updated before the
setup call corresponding to USB_REQ_SET_CONFIGURATION, and before
driver suspend calls. They are valid only when is_otg, and when the
device is acting as a B-Peripheral (so is_a_peripheral is false).
AUTHOR
David Brownell <dbrownell@users.sourceforge.net>.