1USB_GADGET_GET_STRIN(9)     Kernel Mode Gadget API     USB_GADGET_GET_STRIN(9)
2
3
4

NAME

6       usb_gadget_get_string - fill out a string descriptor
7

SYNOPSIS

9       int usb_gadget_get_string(struct usb_gadget_strings * table, int id,
10                                 u8 * buf);
11

ARGUMENTS

13       table
14           of c strings encoded using UTF-8
15
16       id
17           string id, from low byte of wValue in get string descriptor
18
19       buf
20           at least 256 bytes, must be 16-bit aligned
21

DESCRIPTION

23       Finds the UTF-8 string matching the ID, and converts it into a string
24       descriptor in utf16-le. Returns length of descriptor (always even) or
25       negative errno
26
27       If your driver needs stings in multiple languages, you'll probably
28       “switch (wIndex) { ... }” in your ep0 string descriptor logic, using
29       this routine after choosing which set of UTF-8 strings to use. Note
30       that US-ASCII is a strict subset of UTF-8; any string bytes with the
31       eighth bit set will be multibyte UTF-8 characters, not ISO-8859/1
32       characters (which are also widely used in C strings).
33

AUTHOR

35       David Brownell <dbrownell@users.sourceforge.net>
36           Author.
37

39Kernel Hackers Manual 3.10         June 2019           USB_GADGET_GET_STRIN(9)
Impressum