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usbd_interface_descriptor()

Get the interface descriptor for a specific interface setting

Synopsis:

#include <sys/usbdi.h>

usbd_interface_descriptor_t 
   *usbd_interface_descriptor(
       struct usbd_device *device,                          
       _uint8 cfg,                                          
       _uint8 ifc,                                          
       _uint8 alt,                                          
       struct usbd_desc_node **node );

Arguments:

device: An opaque handle used to identify the USB device.
cfg: The device's configuration identifier (bConfigurationValue).
ifc: Interface identifier (bInterfaceNumber).
alt: Alternate identifier (bAlternateSetting).
node: Indicates the descriptor's location for rooting future requests (e.g. endpoints of this interface).

Library:

libusbdi

Description:

The usbd_interface_descriptor() function lets you obtain the interface descriptor for a specific interface setting.

The usbd_interface_descriptor_t structure looks like this:

typedef struct usbd_interface_descriptor {
    _uint8                  bLength;
    _uint8                  bDescriptorType;
    _uint8                  bInterfaceNumber;
    _uint8                  bAlternateSetting;
    _uint8                  bNumEndpoints;
    _uint8                  bInterfaceClass;
    _uint8                  bInterfaceSubClass;
    _uint8                  bInterfaceProtocol;
    _uint8                  iInterface;
} usbd_interface_descriptor_t;

Returns:

A pointer to usbd_interface_descriptor_t on success, or NULL on error.

Classification:

QNX Neutrino, QNX 4

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