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 and returns a pointer to the interface with that particular
interface number, or null.
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!
COPYRIGHT
Kernel Hackers Manual 2.6. July 2010 USB_IFNUM_TO_IF(9)
