USB_IF_DESCR(9S) Data Structures for Drivers USB_IF_DESCR(9S)

usb_if_descr - USB interface descriptor

#include <sys/usb/usba.h>

illumos DDI specific (illumos DDI)

The usb_if_descr_t interface descriptor defines attributes of an interface. A configuration contains one or more interfaces. An interface contains one or more endpoints.

Please refer to Section 9.6.5 of the USB 2.0 specification. The USB 2.0 specification is available at

One or more configuration descriptors are retrieved from a USB device during device enumeration. They can be accessed via usb_get_dev_data(9F).

A interface descriptor has the following fields:

uint8_t     bLength                 Size of this descriptor
                                    in bytes.
uint8_t     bDescriptorType         Set to USB_DESCR_TYPE_IF.
uint8_t     bInterfaceNumber        Interface number (0-based).
uint8_t     bAlternateSetting       Alternate setting number for
                                    this interface and its
                                    endpoints (0-based).
uint8_t     bNumEndpoints           Number of endpoints,
                                    excluding endpoint 0.
uint8_t     bInterfaceClass         Interface Class code
                                    (see below).
uint8_t     bInterfaceSubClass      Sub class code. (See USB 2.0
                                    specification of applicable
                                    interface class for information.)
uint8_t     bInterfaceProtocol      Protocol code.  (See USB 2.0
                                    specification of applicable
                                    interface class for information.)
uint8_t     iInterface              Index of optional string
                                    describing this interface
                                    Valid if > 0. Pass to
                                    usb_get_string_descr(9F) to
                                    retrieve string.
USB 2.0 specification interface descriptor bInterfaceClass field
values are as follows:
        USB_CLASS_APP           Application-specific interface class
        USB_CLASS_AUDIO         Audio interface class
        USB_CLASS_CCID          Chip/Smartcard interface class
        USB_CLASS_CDC_CTRL      CDC control interface class
        USB_CLASS_CDC_DATA      CDC data interface class
        USB_CLASS_SECURITY      Content security interface class
        USB_CLASS_DIAG          Diagnostic interface class
        USB_CLASS_HID           HID interface class
        USB_CLASS_HUB           HUB interface class
        USB_CLASS_MASS_STORAGE  Mass storage interface class
        USB_CLASS_PHYSICAL      Physical interface class
        USB_CLASS_PRINTER       Printer interface class
        USB_CLASS_VENDOR_SPEC   Vendor-specific interface class
        USB_CLASS_WIRELESS      Wireless interface class

See attributes(7) for descriptions of the following attributes:

Architecture PCI-based systems
Interface stability Committed

attributes(7), usb_get_alt_if(9F), usb_get_cfg(9F), usb_get_dev_data(9F), usb_get_string_descr(9F), usb_parse_data(9F), usb_cfg_descr(9S), usb_ctrl_request(9S), usb_dev_descr(9S), usb_dev_qlf_descr(9S), usb_ep_descr(9S), usb_other_speed_cfg_descr(9S), usb_string_descr(9S)
January 5, 2004 OmniOS