USB_ALTNUM_TO_ALTSET(9)                   USB Core APIs                   USB_ALTNUM_TO_ALTSET(9)



NAME
       usb_altnum_to_altsetting - get the altsetting structure with a given alternate setting
       number.

SYNOPSIS
       struct usb_host_interface * usb_altnum_to_altsetting(const struct usb_interface * intf,
                                                            unsigned int altnum);

ARGUMENTS
       intf
           the interface containing the altsetting in question

       altnum
           the desired alternate setting number

DESCRIPTION
       This searches the altsetting array of the specified interface for an entry with the
       correct bAlternateSetting value.

       Note that altsettings need not be stored sequentially by number, so it would be incorrect
       to assume that the first altsetting entry in the array corresponds to altsetting zero.
       This routine helps device drivers avoid such mistakes.

       Don't call this function unless you are bound to the intf interface or you have locked the
       device!

RETURN
       A pointer to the entry of the altsetting array of intf that has altnum as the alternate
       setting number.  NULL if not found.

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