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usbd_descriptor()

Get or set USB descriptors

Synopsis:

#include <sys/usbdi.h>

int usbd_descriptor( struct usbd_device *device, 
                     int set,
                     _uint8 type,
                     _uint16 rtype, 
                     _uint8 index,
                     _uint16 langid, 
                     _uint8 *desc,
                     size_t len );

Arguments:

device: An opaque handle used to identify the USB device.
set: A flag that says to either get or set a descriptor.
type: Type of descriptor (e.g. USB_DESC_DEVICE, USB_DESC_CONFIGURATION, USB_DESC_STRING, USB_DESC_HUB).
rtype: Type of request (e.g. USB_RECIPIENT_DEVICE, USB_RECIPIENT_INTERFACE, USB_RECIPIENT_ENDPOINT, USB_RECIPIENT_OTHER, USB_TYPE_STANDARD, USB_TYPE_CLASS, USB_TYPE_VENDOR).
index: This varies, depending on the request. It's used for passing a parameter to the device.
langid: Identifies the language supported in strings (according to the LANGID table).
desc: Pointer at buffer to put descriptors.
len: The length of the data transfer in bytes.

Library:

libusbdi

Description:

The usbd_descriptor() function lets you obtain the USB descriptors.

Returns:

EMSGSIZE: Buffer too small for descriptor.
ENOMEM: No memory for URB.
ENODEV: Device was removed.
EIO: I/O error on USB device.

Classification:

QNX Neutrino, QNX 4

Safety:
Cancellation point	Yes
Interrupt handler	No
Signal handler	No
Thread	Yes