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 Copyright (c) 2004, Sun Microsystems, Inc.,
 All Rights Reserved
 The contents of this file are subject to the terms of the Common Development and Distribution License (the "License"). You may not use this file except in compliance with the License.
 You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing. See the License for the specific language governing permissions and limitations under the License.
 When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE. If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner]
 USB_GET_STRING_DESCR 9F "Jan 5, 2004"
 NAME
usb_get_string_descr - Get string descriptor from device

 SYNOPSIS
#include <sys/usb/usba.h>



int usb_get_string_descr(dev_info_t *dip,
 uint16_t langid, uint8_t index,
 char *buf, size_t buflen);




 INTERFACE LEVEL
illumos DDI specific (illumos DDI)

 PARAMETERS
dip


Pointer to the device's dev_info structure.



langid


Language ID. Currently only USB_LANG_ID (English ascii) is valid.



index


String index indicating descriptor to retrieve.



buf


Address into which the string descriptor is placed.



buflen


Size of buf in bytes.




 DESCRIPTION
The usb_get_string_descr() function retrieves a parsed string descriptor
from a device. dip specifies the device, while index indicates
which descriptor to return.


String descriptors provide information about other descriptors, or information
that is encoded in other descriptors, in readable form. Many descriptor types
have one or more index fields which identify string descriptors. (See
Sections 9.5 and 9.6 of the USB 2.0 specification.) For
example, a configuration descriptor's seventh byte contains the string
descriptor index describing a specific configuration.


Retrieved descriptors that do not fit into buflen bytes are truncated.
All returned descriptors are null-terminated.

 RETURN VALUES
USB_SUCCESS


String descriptor is returned in buf.



USB_INVALID_ARGS


dip or buf are NULL, or index or buflen is
0.



USB_FAILURE


Descriptor cannot be retrieved.




 CONTEXT
May be called from user or kernel context.

 EXAMPLES
 /* Get the first string descriptor. */

 char buf[SIZE];

 if (usb_get_string_descr(
 dip, USB_LANG_ID, 0, buf, SIZE) == USB_SUCCESS) {
 cmn_err (CE_NOTE, "%s%d: %s",
 ddi_driver_name(dip), ddi_get_instance(dip), buf);
 }




 ATTRIBUTES
See attributes(7) for descriptions of the following attributes:






ATTRIBUTE TYPE ATTRIBUTE VALUE
Architecture PCI-based systems
Interface stability Committed



 SEE ALSO
 attributes (7),  usb_get_dev_data (9F),  usb_string_descr (9S)