USB_IFNUM_TO_IF(9)                        USB Core APIs                        USB_IFNUM_TO_IF(9)



NAME
       usb_ifnum_to_if - get the interface object with a given interface number

SYNOPSIS
       struct usb_interface * usb_ifnum_to_if(const struct usb_device * dev, unsigned ifnum);

ARGUMENTS
       dev
           the device whose current configuration is considered

       ifnum
           the desired interface

DESCRIPTION
       This walks the device descriptor for the currently active configuration to find the
       interface object with the particular interface number.

       Note that configuration descriptors are not required to assign interface numbers
       sequentially, so that it would be incorrect to assume that the first interface in that
       descriptor corresponds to interface zero. This routine helps device drivers avoid such
       mistakes. However, you should make sure that you do the right thing with any alternate
       settings available for this interfaces.

       Don't call this function unless you are bound to one of the interfaces on this device or
       you have locked the device!

RETURN
       A pointer to the interface that has ifnum as interface number, if found.  NULL otherwise.

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