e79bfcb795
Now that the SPDX tag is in all USB files, that identifies the license in a specific and legally-defined manner. So the extra GPL text wording can be removed as it is no longer needed at all. This is done on a quest to remove the 700+ different ways that files in the kernel describe the GPL license text. And there's unneeded stuff like the address (sometimes incorrect) for the FSF which is never needed. No copyright headers or other non-license-description text was removed. Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
68 lines
1.9 KiB
C
68 lines
1.9 KiB
C
// SPDX-License-Identifier: LGPL-2.1+
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/*
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* Copyright (C) 2003 David Brownell
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*/
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#include <linux/errno.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/list.h>
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#include <linux/string.h>
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#include <linux/device.h>
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#include <linux/nls.h>
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#include <linux/usb/ch9.h>
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#include <linux/usb/gadget.h>
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/**
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* usb_gadget_get_string - fill out a string descriptor
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* @table: of c strings encoded using UTF-8
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* @id: string id, from low byte of wValue in get string descriptor
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* @buf: at least 256 bytes, must be 16-bit aligned
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*
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* Finds the UTF-8 string matching the ID, and converts it into a
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* string descriptor in utf16-le.
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* Returns length of descriptor (always even) or negative errno
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*
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* If your driver needs stings in multiple languages, you'll probably
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* "switch (wIndex) { ... }" in your ep0 string descriptor logic,
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* using this routine after choosing which set of UTF-8 strings to use.
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* Note that US-ASCII is a strict subset of UTF-8; any string bytes with
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* the eighth bit set will be multibyte UTF-8 characters, not ISO-8859/1
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* characters (which are also widely used in C strings).
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*/
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int
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usb_gadget_get_string (struct usb_gadget_strings *table, int id, u8 *buf)
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{
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struct usb_string *s;
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int len;
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/* descriptor 0 has the language id */
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if (id == 0) {
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buf [0] = 4;
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buf [1] = USB_DT_STRING;
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buf [2] = (u8) table->language;
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buf [3] = (u8) (table->language >> 8);
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return 4;
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}
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for (s = table->strings; s && s->s; s++)
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if (s->id == id)
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break;
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/* unrecognized: stall. */
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if (!s || !s->s)
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return -EINVAL;
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/* string descriptors have length, tag, then UTF16-LE text */
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len = min ((size_t) 126, strlen (s->s));
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len = utf8s_to_utf16s(s->s, len, UTF16_LITTLE_ENDIAN,
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(wchar_t *) &buf[2], 126);
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if (len < 0)
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return -EINVAL;
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buf [0] = (len + 1) * 2;
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buf [1] = USB_DT_STRING;
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return buf [0];
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}
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EXPORT_SYMBOL_GPL(usb_gadget_get_string);
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