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.TH "USB_GET_DESCRIPTOR" "9" "17 July 2003" "" ""

.SH NAME
usb_get_descriptor \- issues a generic GET_DESCRIPTOR request
.SH SYNOPSIS
.sp
\fB
.sp
int usb_get_descriptor  (struct usb_device * \fIdev\fB, unsigned char \fItype\fB, unsigned char \fIindex\fB, void * \fIbuf\fB, int \fIsize\fB);
\fR
.SH "ARGUMENTS"
.TP
\fB\fIdev\fB\fR
the device whose descriptor is being retrieved
.TP
\fB\fItype\fB\fR
the descriptor type (USB_DT_*)
.TP
\fB\fIindex\fB\fR
the number of the descriptor
.TP
\fB\fIbuf\fB\fR
where to put the descriptor
.TP
\fB\fIsize\fB\fR
how big is ``buf''?
.SH "CONTEXT"
.PP
!in_interrupt ()
.SH "DESCRIPTION"
.PP
Gets a USB descriptor.  Convenience functions exist to simplify
getting some types of descriptors.  Use
\fBusb_get_device_descriptor\fR for USB_DT_DEVICE,
and \fBusb_get_string\fR or \fBusb_string\fR for USB_DT_STRING.
Configuration descriptors (USB_DT_CONFIG) are part of the device
structure, at least for the current configuration.
In addition to a number of USB-standard descriptors, some
devices also use class-specific or vendor-specific descriptors.
.PP
This call is synchronous, and may not be used in an interrupt context.
.PP
Returns the number of bytes received on success, or else the status code
returned by the underlying \fBusb_control_msg\fR call.
.SH "ABOUT THIS DOCUMENT"
.PP
This documentation is free software; you can redistribute
it and/or modify it under the terms of the GNU General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later
version.
.PP
This program is distributed in the hope that it will be
useful, but WITHOUT ANY WARRANTY; without even the implied
warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the GNU General Public License for more details.
.PP
You should have received a copy of the GNU General Public
License along with this program; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston,
MA 02111-1307 USA
.PP
For more details see the file COPYING in the source
distribution of Linux.
.PP
If you have comments on the formatting of this manpage, then please contact
Michael Still (mikal@stillhq.com).
.PP
This documentation was generated with kernel version 2.5.71.