USB_GADGET_GET_STRIN(9)               Kernel Mode Gadget API              USB_GADGET_GET_STRIN(9)



NAME
       usb_gadget_get_string - fill out a string descriptor

SYNOPSIS
       int usb_gadget_get_string(struct usb_gadget_strings * table, int id, u8 * buf);

ARGUMENTS
       table
           of c strings encoded using UTF-8

       id
           string id, from low byte of wValue in get string descriptor

       buf
           at least 256 bytes, must be 16-bit aligned

DESCRIPTION
       Finds the UTF-8 string matching the ID, and converts it into a string descriptor in
       utf16-le. Returns length of descriptor (always even) or negative errno

       If your driver needs stings in multiple languages, you'll probably “switch (wIndex) { ...
       }” in your ep0 string descriptor logic, using this routine after choosing which set of
       UTF-8 strings to use. Note that US-ASCII is a strict subset of UTF-8; any string bytes
       with the eighth bit set will be multibyte UTF-8 characters, not ISO-8859/1 characters
       (which are also widely used in C strings).

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

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