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@users.sourceforge.net>
Author.
COPYRIGHT
Kernel Hackers Manual 3.10 June 2014 USB_GADGET_GET_STRIN(9)
