USB_GADGET_CONFIG_BU(9)               Kernel Mode Gadget API              USB_GADGET_CONFIG_BU(9)



NAME
       usb_gadget_config_buf - builts a complete configuration descriptor

SYNOPSIS
       int usb_gadget_config_buf(const struct usb_config_descriptor * config, void * buf,
                                 unsigned length, const struct usb_descriptor_header ** desc);

ARGUMENTS
       config
           Header for the descriptor, including characteristics such as power requirements and
           number of interfaces.

       buf
           Buffer for the resulting configuration descriptor.

       length
           Length of buffer. If this is not big enough to hold the entire configuration
           descriptor, an error code will be returned.

       desc
           Null-terminated vector of pointers to the descriptors (interface, endpoint, etc)
           defining all functions in this device configuration.

DESCRIPTION
       This copies descriptors into the response buffer, building a descriptor for that
       configuration. It returns the buffer length or a negative status code. The
       config.wTotalLength field is set to match the length of the result, but other descriptor
       fields (including power usage and interface count) must be set by the caller.

       Gadget drivers could use this when constructing a config descriptor in response to
       USB_REQ_GET_DESCRIPTOR. They will need to patch the resulting bDescriptorType value if
       USB_DT_OTHER_SPEED_CONFIG is needed.

AUTHOR
       David Brownell <dbrownell AT users.net>
           Author.

COPYRIGHT
Kernel Hackers Manual 4.8.                 January 2017                   USB_GADGET_CONFIG_BU(9)