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struct_usb_gadget(9) [centos man page]

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; enum usb_device_speed max_speed; enum usb_device_state state; unsigned sg_supported: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; unsigned out_epnum; unsigned in_epnum; }; 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. max_speed Maximal speed the UDC can handle. UDC must support this and all slower speeds. state the state we are now (attached, suspended, configured, etc) sg_supported true if we can handle scatter-gather 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. out_epnum last used out ep number in_epnum last used in ep number 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 <> Author. COPYRIGHT
Kernel Hackers Manual 3.10 June 2014 STRUCT USB_GADGET(9)

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struct_usb_composite_driver - groups configurations into a gadget SYNOPSIS
struct usb_composite_driver { const char * name; const struct usb_device_descriptor * dev; struct usb_gadget_strings ** strings; enum usb_device_speed max_speed; unsigned needs_serial:1; int (* bind) (struct usb_composite_dev *cdev); int (* unbind) (struct usb_composite_dev *); void (* disconnect) (struct usb_composite_dev *); void (* suspend) (struct usb_composite_dev *); void (* resume) (struct usb_composite_dev *); struct usb_gadget_driver gadget_driver; }; MEMBERS
name For diagnostics, identifies the driver. dev Template descriptor for the device, including default device identifiers. strings tables of strings, keyed by identifiers assigned during bind and language IDs provided in control requests. Note: The first entries are predefined. The first entry that may be used is USB_GADGET_FIRST_AVAIL_IDX max_speed Highest speed the driver supports. needs_serial set to 1 if the gadget needs userspace to provide a serial number. If one is not provided, warning will be printed. bind (REQUIRED) Used to allocate resources that are shared across the whole device, such as string IDs, and add its configurations using usb_add_config(). This may fail by returning a negative errno value; it should return zero on successful initialization. unbind Reverses bind; called as a side effect of unregistering this driver. disconnect optional driver disconnect method suspend Notifies when the host stops sending USB traffic, after function notifications resume Notifies configuration when the host restarts USB traffic, before function notifications gadget_driver Gadget driver controlling this driver DESCRIPTION
Devices default to reporting self powered operation. Devices which rely on bus powered operation should report this in their bind method. Before returning from bind, various fields in the template descriptor may be overridden. These include the idVendor/idProduct/bcdDevice values normally to bind the appropriate host side driver, and the three strings (iManufacturer, iProduct, iSerialNumber) normally used to provide user meaningful device identifiers. (The strings will not be defined unless they are defined in dev and strings.) The correct ep0 maxpacket size is also reported, as defined by the underlying controller driver. AUTHOR
David Brownell <> Author. COPYRIGHT
Kernel Hackers Manual 3.10 June 2014 STRUCT USB_COMPOSITE(9)
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