struct_usb_gadget - represents a usb slave device
2. SYNOPSIS ▲
3. MEMBERS ▲
Function pointers used to access hardware-specific operations.
Endpoint zero, used when reading or writing responses to driver setup requests
List of other endpoints supported by the device.
Speed of current connection to USB host.
Maximal speed the UDC can handle. UDC must support this and all slower speeds.
the state we are now (attached, suspended, configured, etc)
true if we can handle scatter-gather
True if the USB device port uses a Mini-AB jack, so that the gadget driver must provide a USB OTG descriptor.
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.
OTG device feature flag, indicating that the A-Host enabled HNP support.
OTG device feature flag, indicating that the A-Host supports HNP at this port.
OTG device feature flag, indicating that the A-Host only supports HNP on a different root port.
Identifies the controller hardware type. Used in diagnostics and sometimes configuration.
Driver model state for this abstract device.
last used out ep number
last used in ep number
4. 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 thatAqs 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).
5. AUTHOR ▲
David Brownell <>
6. COPYRIGHT ▲