alistair23-linux/drivers/staging/ccg/usbstring.c
Sebastian Andrzej Siewior e220ff75db staging: ccg: include all sourced files
This Android gadget includes a bunch of .c files. Fixing normal gadgets
is not the real problem but this gadget is not always fixable since the
problem here are fundumential / design.

*I* wanted to get this removed but other people want to keep it even
though there were reports that Android itself is not using it. Some
poeple think that it is better to have this instead of nothing and other
argue that they need sdb and mass storage gadget. The sdb function is
not provided by ccg so I don't see the point of this. I don't see any
logical reasoning behind it and I decided that it is time for retreat.

This patch brings all dependencies of ccg into staging so I can do
whatever I want in drivers/usb/gadget without breaking ccg.

Cc: devel@driverdev.osuosl.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>
2012-09-10 15:35:35 +03:00

72 lines
2 KiB
C

/*
* Copyright (C) 2003 David Brownell
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published
* by the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*/
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/string.h>
#include <linux/device.h>
#include <linux/init.h>
#include <linux/nls.h>
#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>
/**
* usb_gadget_get_string - fill out a string descriptor
* @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
*
* 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).
*/
int
usb_gadget_get_string (struct usb_gadget_strings *table, int id, u8 *buf)
{
struct usb_string *s;
int len;
/* descriptor 0 has the language id */
if (id == 0) {
buf [0] = 4;
buf [1] = USB_DT_STRING;
buf [2] = (u8) table->language;
buf [3] = (u8) (table->language >> 8);
return 4;
}
for (s = table->strings; s && s->s; s++)
if (s->id == id)
break;
/* unrecognized: stall. */
if (!s || !s->s)
return -EINVAL;
/* string descriptors have length, tag, then UTF16-LE text */
len = min ((size_t) 126, strlen (s->s));
len = utf8s_to_utf16s(s->s, len, UTF16_LITTLE_ENDIAN,
(wchar_t *) &buf[2], 126);
if (len < 0)
return -EINVAL;
buf [0] = (len + 1) * 2;
buf [1] = USB_DT_STRING;
return buf [0];
}